K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Preface

This book is written for the young otolaryngologist who is already acquainted with the field through recent formal residency training, as well as for other physicians who are intereseted in concise descriptions of otolaryngologic conditions.

It is not the intent of the authors to write a complete review of otolaryngology, much less a textbook of otolaryngology. It is a discussion of many current concepts in the field. The materials in this book came from numerous sources. The first edition was compiled from the editor's notes for his own Board Examinations, with contributions from authorities in the field. This revised third edition has been updated, as well as expanded, to make it more useful to medical students and physicians in other specialties.

It is hoped that the reader will freely refer to the list of references for more in-depth dissertations.

KJL

Chapter 1: Anatomy of the Ear

General Information

1. The temporal bone forms part of the side and base of the skull. It constitutes two- thirds of the floor of the middle cranial fossa and one-third of the floor of the posterior fossa. There are four parts to the temporal bone:

a. Squamosa

b. Mastoid

c. Petrous

d. Tympanic.

2. The following muscles are attached to the mastoid process:

a. Sternocleidomastoid

b. Splenius capitis

c. Longissimus capitis

d. Digastric

e. Anterior, superior, posterir, auricular.

1 (The temporalis muscle attaches to the squamosa portion of the temporal bone and not to the mastoid process.)

3. The auricle (Fig. 1-1) is made of elastic cartilage, the cartilaginous canal of fibrocartilage. The cartilaginous canal constitutes one-third of the external auditory canal (whereas the eustachian tube is two-thirds cartilaginous); the remaining two-third is osseous.

4. The skin over the cartilaginous canal has sebaceous glands, ceruminous glands, and hair follicles. The skin over the bony canal is tight and has not subcutaneous tissue except periosteum.

5. Boundaries of the external auditory canal

Anteriorly: mandibular fossa parotid

Posteriorly: mastoid

Superiorly: (medially) epitympanic recess (laterally) cranial cavity

Inferiorly: parotid.

The anterior portion, the floor, and part of the posterior portion of the bony canal are formed by the tympanic part of the temporal bone. The rest of the posterior canal and the roof are formed by the squamosa.

6. Boundaries of the tympanum

Medially: lateral semicircular canal and VII nerve

Superiorly: tegmen

Anteriorly: zygomatic arch

Laterally: squamosa (scutum)

Inferiorly: fossa incudis

Posteriorly: aditus.

7. Boundaries of the tympanic cavity

Roof: tegmen

Floor: jugular wall and styloid prominence

Posteriorly: mastoid, stapedius, pyramidal prominence

2 Anteriorly: carotid wall, eustachian tube, tensor tympani

Medially: labyrinthine wall

Laterally: tympanic membrane, scutum (latero-superior).

8. The auricle is attached to the head by:

a. Skin

b. An extension of cartilage to the external auditory canal cartilage

c. Ligaments:

1) Anterior ligament (zygoma to helix and tragus)

2) Superior ligament (external auditory canal to the spine of the helix)

3) Posterior ligament (mastoid to concha)

d. Muscles

1) Anterior auricular muscle

2) Superior auricular muscle

3) Posterior auricular muscle.

9. Notch of Rivinus is the notch on the squamosa, medial to which lies Shrapnell's membrane. The tympanic ring is not a complete ring, giving a dehiscence superiorly.

10. Meckel's cave is the concavity on the superior portion of the temporal bone in which the gasserian ganglion (V) is located.

11. Dorello's canal is between the petrous tip and the sphenoid bone. It is the groove of the Vi nerve.

(Gradenigo's syndrome is characterized by:

a. Pain behind the eye

b. Diplopia

c. Aural discharge.

It is secondary to petrositis with involvement of the VI nerve.)

3 12. The suprameatal triangle of Macewen's triangle is posterior and superior to the external auditory canal. It is bound at the meatus by the Spine of Henle, otherwise called the suprameatal spine. This triangle approximates the position of the antrum medially. Tegmen mastoidi is the thin plate over the antrum.

13. Trautmann's triangle is demarcated by the bony labyrinth, the sigmoid sinus, and the superior petrosal sinus or dura.

Citelli's angle is the sinodural angle. It is located between the sigmoid sinus and the middle fossa dura plate. Others consider the superior side of Trautmann's triangle to be Citelli's triangle.

Solid angle is the angle formed by the three semicirculat canals.

Scutum is the thin plate of bone which constitutes the lateral wall of the epitympanum. It is part of the squamosa.

Mandibular fossa is bound by the zygomatic, squamosa, and tympanic bones.

Canal of Huguier transmits the chorda tympani out of the temporal bone anteriorly. It is situated lateral to the roof of the protympanum.

Foramen of Huschke is located on the anterior tympanic plate along a nonossified portion of the plate. This is near the fissures of Santorini.

Porus acusticus is the "mouth" of the internal auditory canal. The canal is divided horizontally by the crista falciformis.

14. There are three parts to the inner ear (Fig. 1-2):

a. Pars superior: vestibular labyrinth (utricle and semicircular canals)

b. Pars inferior: cochlea and saccule

c. Endolymphatic sac and duct.

15. There are four small outpocketings from the perilymph space:

a. Along the endolymphatic duct

b. Fissula ante fenestram

c. Fossula post fenestram

d. Periotic duct.

4 16. There are four openings into the temporal bone:

a. Internal auditory canal

b. Vestibular aqueduct

c. Cochlear aqueduct

d. Subarcuate fossa.

17. The ponticulum is the ridge of bone between the oval window niche and sinus tympani.

18. The subiculum is a ridge of bone between the round window niche and sinus tympani.

19. Körner's septum separates the squamosa from the petrous air cells.

20. Only one-third of the population has a pneumatized petrous portion of the temporal bone.

21. Scala communis is where the scala tympani joins the scala vestibuli. The helicotrema is at the apex of the cochlea where the two join (Fig. 1-3).

22. The petrous pyramid is the strongest bone in the body.

23. The upper limits of the internal auditory canal diameter is 8 mm.

24. The cochlear aqueduct is a bony channel connecting the scala tympani of the basal turn with the subarachnoid spoace of the posterior cranial cavity. The average adult cochlear aqueduct is 6.2 mm long.

Middle Ear

(Tympanic plexus = V3, IX, and X)

V3 --> Auriculotemporal nerve IX --> Jacobson's nerve X --> Auricular nerve.

Inner Ear

Superior vestibular nerve --> Superior and horizontal semicircular canals --> Utricle --> Voit nerve --> Saccule

5 Inferior vestibular nerve --> Saccule --> Posterior semicircular canal

Blood Supply

External carotid artery --> Posterior auricular artery --> Outer ear. --> Superficial temporal artery --> Outer ear.

External carotid artery --> Maxillary artery --> Anterior tympanic branch --> Middle ear. --> Maxillary artery --> Middle meningeal artery --> Superior tympanic branch --> Middle ear. --> Maxillary artery --> Middle meningeal artery --> Superficial petrosal branch --> Middle ear.

Internal carotid artery --> Caroticotympanic artery --> Anastomoses with branches from stylomastoid, maxillary and ascending pharyngeal arteries.

Postauricular artery --> Posterior tympanic --> Middle ear. --> Stylomastoid branch --> Middle ear.

Ascending pharyngeal artery --> Inferior tympanic branch --> Middle ear.

(The long process of the incus receives the least blood supply and hence is the most frequently necrosed.)

External carotid artery --> Occipital artery --> Meningeal branch --> Mastoid.

Internal carotid artery --> Subarcuate vessels --> Mastoid.

External carotid artery --> Maxillary artery --> Deep auricular branch --> Lateral surface TM. --> Maxillary artery --> Ant tympanic branch --> Medial surface TM. --> Posterior auricular artery --> Stylomastoid branch --> Med surf TM.

Ant inf cerebellar artery --> Internal auditory artery --> Common cochlear artery --> Main cochlear artery --> All of cochlea except one-third of the basal turn. --> Internal auditory artery --> Common cochlear artery --> Main cochlear artery --> Cochlear ramus --> The one-third of the basal turn. --> Internal auditory artery --> Common cochlear artery --> Cochlear vestibular artery

6 --> Posterior vestibular artery --> Inferior portion of utricle and saccuel and posterior semicircular canal. --> Internal auditory artery --> Anterior vestibular artery --> Cochlear vestibular artery --> Posterior vestibular artery --> Inferior portion of utricle and saccuel and posterior semicircular canal. --> Internal auditory artery --> Anterior vestibular artery --> Superior portion of utricle and saccule, superior and horizontal semicircular canals.

Basilar artery (occasionally) --> Internal auditory artery --> Common cochlear artery --> Main cochlear artery --> All of cochlea except one-third of the basal turn. --> Internal auditory artery --> Common cochlear artery --> Main cochlear artery --> Cochlear ramus --> The one-third of the basal turn. --> Internal auditory artery --> Common cochlear artery --> Cochlear vestibular artery --> Posterior vestibular artery --> Inferior portion of utricle and saccuel and posterior semicircular canal. --> Internal auditory artery --> Anterior vestibular artery --> Cochlear vestibular artery --> Posterior vestibular artery --> Inferior portion of utricle and saccuel and posterior semicircular canal. --> Internal auditory artery --> Anterior vestibular artery --> Superior portion of utricle and saccule, superior and horizontal semicircular canals.

Figure 1-4. Sensory Innervation of the Auricle

Posterior surface:

--> C3 via greater auricular nerve --> C2,3 via lesser occipital nerve --> X auricular branch --> VII sensory twigs.

Anterior surface:

--> V3 auriculotemporal nerve --> X auricular branch --> VII sensory twigs.

Figure 1-5. Cross-Section of Internal Auditory Canal

Anterior - VII - "Bill's Bar" - Sup vestibular nerve - Posterior - Cochlear nerve - Inferior vestibular nerve.

Figure 1-6. Measurements of the Tympanic Membrane

Vertical 9-10 mm Horizontal 8-9 mm.

7 The tympanic membrane has four layers:

1. Squamous epithelium

2. Radiating fibrous layer

3. Circular fibrous layer

4. Mucosa layer.

Average total layer of tympanic membrane: 70-80 mm2.

Average vibrating surface of tympanic membrane: 55 mm2.

Venous Drainage

Vertebral Cavernous External jugular III Occipital Superior petrosal Mastoid emissary veins III Lateral sinus Sigmoid sinus Sigmoid sinus I Internal jugular vein Inf petrosal sinus

Ossicles

Malleus

1. Head

2. Neck

3. Manubrium

4. Anterior process

5. Lateral or short process.

Stapes

1. Head

2. Posterior crus

3. Anterior crus

4. Footplate (average 1.41 mm x 2.99 mm).

8 Incus

1. Body

2. Short process

3. Long process (lenticular process).

Ligaments

Malleus

1. Superior malleal ligament (head to roof of epitympanum)

2. Anterior malleal ligament (neck near anterior process to sphenoid bone through the petrotympanic fissure)

3. Tensor tympani (medial surface of upper end of manubrium to cochleariform process)

4. Lateral malleal ligament (neck to tympanic notch).

Incus

1. Superior incudal ligament (body to tegment)

2. Posterior incudal ligament (short process to floor of incudal fossa).

Stapes

1. Stapedial tendon (apex of the pyramidal process to the posterior surface of the neck of the stapes).

2. Annular ligament (footplate to margin of vestibular fenestrum).

Malleal:Incudal joint is a diarthroidal joint.

Incudo:Stapedial joint is a diarthroidal joint.

Stapedial:Labyrinthal joint is a syndesmotic joint.

Middle Ear Folds of Significance

1. Anterior malleal fold: neck of the malleus to anterosuperior margin of the tympanic sulcus.

2. Posterior malleal fold: neck to posterosuperior margin of the tympanic sulcus.

9 3. Lateral mallear fold: neck to neck in an arch form and to Shrapnell's membrane.

4. Anterior pouch of von Tröltsch: Lies between the anterior malleal fold and the portion of the tympanic membrane anterior to the handle of the malleus.

5. Posterior pouch of von Tröltsch: Lies between the posterior malleal fold and the portion of the tympanic membrane posterior to the handle of malleus.

Prussak's space (Fig. 1-7) is bound:

1. Anteriorly by the lateral malleolar fold

2. Posteriorly by the lateral malleolar fold

3. Superiorly by the lateral malleolar fold

4. Inferiorly by the lateral process of the malleus

5. Medially by the neck of the malleus

6. Laterally by Shrapnell's membrane.

The oval window sits in the sagittal plane.

The round window sits in the transverse plane and is protected by an anterior lip from the promontory. It faces posteroinferiorly as well as laterally.

The tensor tympani inserts from the cochleariform process onto the medial surface of the upper end of the manubrium. It supposedly pulls the tympanic membrane medially, thus tensing it. It also draws the malleus medially and upward. It raises the resonant frequency and attenuates low frequencies.

The stapedius muscle most frequently attaches to the posterior neck of the stapes. Occasionally it is attached to the posterior crus or head and rarely to the lenticular process. It is attached posteriorly at the pyramidal process. It pulls the stapes posteriorly, supposedly raises the resonant frequency of the ossicular chain and attenuates sound.

Eustachian Tube

1. It is 17-18 mm at birth and grows to about 35 mm in adult life.

2. At birth the tube is horizontal and grows to be at an incline of 45° in adult life. Thus the pharyngeal orifice is about 15 mm lower than the tympanic orifice.

3. It can be divided into an anteromedial cartilaginous portion (24 mm) and a posterolateral bony (11 mm) portion. The narrowest part of the tube is at the junction of the bony and the cartilaginous portions. (Reminder: The external auditory canal is one-third cartilaginous and two-thirds bony.)

10 4. The cartilaginous part of the tube is lined by pseudostratified columnar cilicated epithelium but toward the tympanic orifice it is lined by ciliated cuboidal epithelium.

5. It opens by the action of the tensor palati (innervated by the third division of the V nerve) acting synergistically with the levator veli palatini (innervated by the vagus). In children the only muscle that works is the tensor palati because the levator palati is separated from the eustachian tube cartilage by a considerable distance. Therefore, a cleft palate child with poor tensor palati function is expected to have eustachian tube problems until the levator palati starts to function.

6. In a normal individual a pressure difference of 200-300 mm H2O is needed to produce air flow.

7. It is easier to expel air from the middle ear than to get it into the middle ear (reason for more tubal trouble with descent in an airplane).

8. A pressure of -30 mm Hg or lower for 15 minutes can produce a transudate in the middle ear. A pressure differential of 90 mm Hg or greater may "lock" the eustachian tube preventing opening of the tube by the muscles. This is called the "critical pressure difference".

9. If the pressure differential exceeds 100 mm Hg, the tympanic membrane may rupture.

10. A Valsalva maneuver generates about 20-40 mm Hg pressure.

11. The lymphoid tissues within the tube have been referred to as the tonsil of Gerlach.

12. The tympanic ostium of the tube is at the anterior wall of the tympanic cavity about 4 mm above the most inferior part of the floor of the cavity. The diameter of the ostium is 3-5 mm. The size of the pharyngeal ostium varies from 3-10 mm in its vertical diameter and 2-5 mm in its horizontal diameter.

Embryology of the Ear

The Auricle

On the sixth week of gestation, condensation of the mesoderm of the first and second arches occurs to give rise to six hillocks called the Hillocks of His. The first three hillocks are derived from the first arch while the second arch contributes to the last three (Fig. 1-9).

First arch: First hillock --> tragus (1). Second hillock --> helical crus (2). Third hillock --> helix (3).

Second arch: Fourth hillock --> antihelix (4). Fifth hillock --> antitragus (5). Sixth hillock --> lobule and lower helix (6).

11 On the seventh week: Formation of cartilage is in progress.

On the twelfth week: The auricle is formed by fusion of the hillocks.

On the twentieth week: It has reached adult shape although it does not reach adult size till one is 9 years old.

The concha is formed by three separate areas from the first groove (ectoderm) (see Fig. 1-9).

a. Middle part of the first groove: Concha cavum. b. Upper part of the first groove: Concha cymba. c. Lower part of the first groove: Intertragus incisura.

The External Auditory Canal

On the eight week of gestation, the surface ectoderm in the region of the upper end of the first pharyngeal groove (dorsal) thickens. This solid core of epithelium continues to grow toward the middle ear. Simultaneously, the concha cavum deepends to form the outer one-third of the external auditory canal. By the twenty-first week this core begins to resorb and "hollow out" to form a channel. The innermost layer of ectoderm remains to become the superficial layer of the tympanic membrane. Formation of the channel is completed by the twenty-eight week. At birth, the external auditory canal is neither ossified nor of adult size. Completion of ossification occurs around age 3 and adult size is reached at age 9.

The Eustachian Tube and the Middle Ear

During the third week of gestation, the first and second pharyngeal pouches lie laterally on either side of what is to become the oral and pharyngeal tongue. As the third arch enlarges, the space between the second arch and the pharynx (first pouch) is compressed and becomes the eustachian tube. The "outpocketing" at the lateral end becomes the middle ear space. Because of the proximity to the first, second, and third arches, the V, VII, and IX nerves are found in the middle ear. By the tenth week, pneumatization begins. The antrum appears on the twenty-third week. However, it is of interest that the middle ear is filled with mucoid connective tissue until the time of birth. The twenty-eight week marks the apparition of the tympanic membrane which is derived from all three origins.

a. Ectoderm --> squamous layer.

b. Mesoderm --> fibrous layer.

c. Entoderm --> mucosal layer.

Between the twelfth and the 28th week, four primary mucosal sacs emerge, each becoming a specific anatomic region of the middle ear.

a. Saccus anticus --> anterior pouch of von Tröltsch.

12 b. Saccus medius --> epitympanum and petrous area.

c. Saccus superior --> posterior pouch of von Tröltsch, part of the mastoid, inferior incudal space.

d. Saccus posterior --> round window and oval window niches, sinus tympani.

At birth, the embryonic subepithelium is resorbed and pneumatization continues in the middle ear, antrum and mastoid. Pneumatization of the petrous portion of the temporal bone, being the last to arise, continues until puberty.

The middle ear is well formed at birth and enlarges only slightly postnatally. At age 1, the mastoid process appears. At age 3, the tympanic ring and osseous canal are calcified.

The eustachian tube measures approximately 17 mm at birth and continues to grow to 35 mm in adulthood.

The Malleus and Incus

On the sixth week of embryonic development, the malleus and the incus appear as a single mass. By the eight week they are separated and the malleoincudal joint is formed. The head and neck of the malleus are derived from Meckel's cartilage (first arch mesoderm), the anterior process from the process of Folius (mesenchyme bone) and the manubrium from the Reichert's cartilage (second arch mesoderm). The body and short process of the incus originate from Meckel's cartilage (first arch mesoderm) and the long process from Reichert's cartilage (second arch mesoderm). By the sixteenth week, the ossicles reach adult size. On the sixteenth week, ossification begins and appears first at the long process of the incus. On the seventeenth week, the ossification center becomes visible on the medial surface of the neck of the malleus and spreads to the manubrium and the head. At birth, the malleus and incus are of adult size and shape. The ossification of the malleus is never complete so that part of the manubrium remains cartilaginous. (The lenticular process is also known as "sylvian apophysis" or "os orbiculare").

The Stapes

At 4.5 weeks the mesenchymal cells of the second arch condense to form the blastema. The VII nerve divides the blastema into stapes, interhyale and laterohyale. On the seventh week, the stapes ring emerges around the stapedial artery. The lamina stapedialis, which is of the otic mesenchyme, appears to becomes the footplate and annular ligament. At 8.5 weeks, the incudalstapedial joint develops. The interhyale becomes the stapedial muscle and tendon, the laterohyale becomes the posterior wall of the middle ear. Together with the otic capsule, the laterohyale also becomes the pyramidal process and facial canal. The lower part of the facial canal is said to be derived from Reichert's cartilage.

On the tenth week, the stapes changes its ring shape to "stirrup" shape. On the nineteenth week, ossification begins and starts at the obturator surface of the stapedial base. The ossification is completed by the 28th week except for the vestibular surface of the footplate which remains cartilaginous throughout life. At birth the stapes if of adult size and

13 form.

The Inner Ear

On the third week neuroectoderm and ectoderm lateral to the first branchial groove condense to form the otic placode. The latter invaginates until completely submerged and surrounded by mesoderm to become the otocyst or otic vesicle by the fourth week. The fifth week marks the appearance of a wide dorsal and a slender ventral part of the otic vesicle. Between these two parts, the endolymphatic duct and sac develop. On the sixth week, the semicircular canals take shape and by the eight week, together with the utricle, they are fully formed. Formation of the basal turn of the cochlea takes place on the seventh week and by the twelfth week the complete two and a half turns are developed. Development of the saccule follows that of the utricle. Evidently, the pars superior (semicircular canals and utricle) is developed before the pars inferior (saccculus and cochlea). Formation of the membranous labyrinth without the end organ is said to be complete by the fifteenth week of gestation.

Concurrent with the formation of the membranous labyrinth, the precursor of the otic capsule emerges on the eight week as a condensation of mesenchyme precartilage. The 14 centers of ossification can be identified on the fifteenth week and ossification is completed on the 23rd week of gestation. The last area to ossify is the fissula ante fenestram which may remain cartilaginous throughout life. Other than the endolymphatic sac which continues to grow until adulthood, the membranous and bony labyrinth are of adult size at the 23rd week of embryonic development. The endolymphatic sac is the first to appear and the last to stop growing.

At the third week, the common maxula first appears. Its upper part differentiates into the utricular macula and the cristae of the superior and lateral semicircular canals, whereas its lower part becomes the macula of the saccule and the cristae of the posterior semicircular canal. On the eight week, two ridges of cells as well as the stria vascularis are identifiable. On the eleventh week, the vestibular end organs complete with sensory and supporting cells are formed. On the twentieth week, development of the stria vascularis and the tectorial membrane is completed. On the 23rd week, the two ridges of cells divide into inner ridge cells and outer ridge cells. The inner ridge cells become the spiral limbus, the outer ones become the hair cells, pillar cells, Hensen's cells, and Deiters' cell. On the 26th week, the tunnel of Corti and canal of Nuvel are formed.

The neurocrest cells lateral to the rhombencephalon condense to form the acoustic- facial ganglion which differentiates into the facial geniculate ganglion, superior vestibular ganglion (utricle, superior and horizontal semicircular canals) and inferior ganglion (saccule, posterior semicircular canal and cochlea).

At birth, four elements of the temporal bone are distinguishable: petrous, squamous, tympanic ring, and styloid process. The mastoid antrum is present but the mastoid process is not formed until the end of the second year of life and pneumatization of the mastoid soon follows. The tympanic ring extends laterally after birth forming the osseous canal.

14 Clinical Information

1. Congenital microtia occurs about 1:20.000 births.

2. The auricle is formed early. Therefore, malformation of the auricle implies malformation of the middle ear, mastoid, and VII nerve. On the other hand, a normal auricle with canal atresia indicates development in the 28th week, by which time ossicles and middle ear are already formed.

3. Improper fusion of the first and second branchial arches results in a preauricular sinus tract (epithelial lined).

4. Malformation of first branchial arch and groove results in:

a. Auricle abnormality (first and second arches)

b. Bony meatus atresia (first groove)

c. Abnormal incus and malleus (first and second arches)

d. Abnormal mandible (first arch).

When the maxilla is also malformed, this constellation of findings is called Treacher- Collins syndrome (mandibular-facial dysostosis).

a. Outward-downward slanted eyes (antimongoloid)

b. Notched lower lid

c. Short mandible

d. Bony meatal atresia

e. Malformed incus and malleus

f. Fishmouth

5. Abnormalities of the otic capsule and labyrinth are rare because they are phylogenetically ancient.

6. An incidence of 20-30% dehiscent tympanic portion of the VII nerve has been reported.

7. The incidence of absent stapedius tendon, muscle, and pyramidal eminence is estimated at 1%.

8. Twenty percent of preauricular cysts are bilateral.

15 9. In the very young infants, Hyrtl's fissure affords a route of direct extension of infection from the middle ear to the subarachnoid spaces. The fissure closes as the infant grows. Hyrtl's fissure extends from the subarachnoid space near the glossopharyngeal ganglion to the hypotympanum just inferior and anterior to the round window. (Eggston, 1947.)

16 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 2: Audiology

Theories of Hearing

There are several theories regarding the manner in which sound is perceived by the human ear. The following are several of the most common and accepted theories.

The Place Theory

The place theory is based on the assumption that pitch discrimination is determined by a certain place along the basilar membrane being set into maximum vibration, which in turn excites the sensory nerve fibers at that place. It was presumed that every particular section of the basilar membrane is tuned so that its resonance characteristics will correspond to the frequency of some audible tone. This theory was propounded by Hermann von Helmholtz, who considered the 24.000 or so transverse fibers of the basilar membrane to be tuned like the strings of a piano or harp. It was thought that when sound waves containing those frequencies were received by the ear, the appropriate fibers would resonate automatically to those pitches, thus stimulating the hair cells of the organ of Corti which rests on those fibers of the membrane. It was assumed that because the trasnverse fibers at the base of the cochlea are short, they thought to resonate to lower pitches. Later exponents of the place theory did not think that the tuning of the basilar membrane was as sharp as Helmholtz has thought, but agreed that a particular region of stimulation in the basilar membrane was responsible for the perception of a particular pitch.

The Frequency Theory

The frequency theory explains pitch perception by suggesting that all parts of the basilar membrane are stimulated by every frequency and that the determination of pitch perception is based upon the number of times per second that the fibers of the auditory nerve discharge. For example, this theory holds that an auditory stimulus of 1000 Hz causes fibers within the auditory nerve to discharge at a rate of 1000 times per second, and that pitch is appreciated in the brain, not in the cochlea. The frequency theory also is known as the "telephone" theory, because displacements along the basilar membrane are in phase with the movements of the stapes, much like a telephone diaphragm. Studies of action potentials of nerve fibers have demonstrated that the maximum rate of discharge of nerve impulses from the peripheral auditory nerve fibers is about 1000/sec. This means that the discrimination of pitches above this frequency could not be explained on the basis of the frequency theory. Rutherford, and more recently Boring, were exponents of this theory.

The Volley Theory

The volley theory combines elements of the place theory and the frequency theory, and holds that perception of pitch for frequencies up to 5000 Hz can be explained on the basis of the frequency of nerve impulses firing in volleys. It holds that the primary explanation for perception of pitch for frequencies in excess of 5000 Hz is the place of greatest excitation along the basilar membrane. The volley theory is advocated by Weaver.

1 The Travelling Wave Theory

The travelling wave theory is one of the place theories which holds that pitch discrimination is determined when a certain place along the basilar membrane is set into maximum vibration. The place on the membrane where the nerve endings will be stimulated depends upon where the maximum displacement of the travelling wave occurs. Support for the travelling wave theory is contributed by experimentation carried out by George von Bekesy. According to Bekesy, the energy for creating the travelling wave comes from the stapes, but the wave starting at one end, runs along the length of the membrane, gradually increasing in amplitude until it gains maximum displacement. The wave travels from the base to the apex of the cochlea, and the maximum amplitude occurs at a point along the basilar membrane that corresponds to the frequency of the stimulus. Increasing the frequency of the tone moves the place of maximal vibration toward the base of the cochlea, decreasing the frequency moves it in the direction of the apex of the cochlea.

The above four theories of hearing, a few more acceptable than others, are explanations of how the human ear discriminates pitch. When intensity discrimination in the human ear is considered, it appears that the number of nerve fibers activated, the total number of impulses per second of all fibers, and the existence of fibers that tend to respond to stimuli which fit a particular category of intensity, are the factors on which intensity discrimination are dependent.

Bone Conduction

When testing pure tone thresholds under headphones, otherwise known as air- conduction testing, the integrity of the outer, middle, and inner ear is being tested as a whole. In essence, air-conduction results indicate the amount of hearing loss the patient is experiencing. When testing pure tone bone-conduction thresholds, the integrity of only the inner ear is indicated. Therefore, the combination of air-conduction and bone-conduction tests indicates the amount of conductive hearing loss present. The difference between air- conduction and bone-conduction results equals the conductive hearing loss.

Bone conduction testing is performed using a bone vibrator attached to the skull with a headband. Conventional bone-conduction testing is done at the mastoid process of the temporal bone. The vibrator sets the fluid of the cochlea in motion. Two patterns of skull and fluid vibration are as follows:

a. Below 800 Hz the skull vibrates as a unit and the ossicles, mandible, and cochlear fluid lag behind due to inertia. Since the ossicular chain lags, the stapes moves relative to the oval window and stimulates hearing as in air conduction.

b. Above 800 Hz compressional vibration occurs. This means that when the compressional forces of the skull are transmitted to the inner ear, the noncompressible fluids of the entire cochlea move toward or away from the mobile round window. Since the fluid is in motion, it may cause depression of the basilar membrane, resulting in the sensation of hearing.

2 Physiology of the Middle Ear Related to Hearing

The average surface area of the tympanic membrane - 70-80 mm2.

Weight of tympanic membrane = 14 mg, elasticity = 4.9 x 10-8 dynes.

The average surface area of the vibrating portion of the tympanic membrane = 55 mm2.

The surface of the footplate = 3.2-3.5 mm2.

The surface area of the round window is 2 mm2.

Lever mechanism = (Length of the long process of the malleus) / (Length of the long process of the incus) = 1.3/1or2.5dB

Hydraulic action = (Vibrating TM) / (Footplate) = 55 / 3.2 = 17 or 25 dB

Total transformer ratio = (1.3 x 17)/1=22/1or27.5 dB.

Glossary of Miscellaneous Terminology Related to Physiology of the Human Ear

1. The human ear has an auditory range from approximately 10 Hz through 24.000 Hz. The intensity range is from approximately 0 dB through 120 dB (0.0002 dynes/cm2 through 200 dynes/cm2).

2. In the middle ear, a high-frequency hearing loss will result with an increase of mass. An increase of stiffness will cause a low-frequency hearing loss.

3. Maximum conductive hearing loss:

a. With intact ossicular chain with no pars tensa - 40-45 dB

b. With osscicular discontinuity with no pars tensa - 40-45 dB

c. Ossicular discontinuity with intact tympanic membrane - 50-55 dB.

4. The resonant frequency of the external auditory canal is 3000 Hz. The resonant frequency of the tympanic membrane and ossicles is 800 Hz. The maximum increase in sound pressure occurs when the applied sound has a wavelength four times the effective length of the external auditory canal.

5. Other definitions related to perception of sound in the human ear:

a. Hyperacusis is an unusually low hearing threshold level. (It is not necessarily associated with intolerance to sound.)

3 b. Dysacusis indicates a disturbance of speech discrimination, abnormal tone quality, pitch, or loudness.

c. Hypoacusis is an unusually high hearing threshold level.

d. Paracusis willisane is the phenomenon whereby a person with conductive hearing loss hears better in background noise.

e. Central hearing loss occurs because of a lesion within the auditory nervous system, does not involve the primary neuron, and may or may not involve decreased hearing thresholds.

f. Central auditory imperception indicates receptive (sensory) aphasia, in which hearing thresholds are good but discrimination or understanding of the stimuli is poor.

g. Monoaural diplacusis is a hearing disorder which affects the perception of pure tones as impure or noisy.

Binaural diplacusis is a disorder in which the same pitch sounds different in both ears.

h. Phonemic regression occurs when discrimination is so poor that the listener is unable to differentiate phonemes. Presbyacusis is a common problem among the geriatric population, whose common complaint is lack of understanding even if loud enough to hear. This problem is due to the loss of central communicating neurons and axons.

6. Occlusion effect occurs when the external auditory canal of the test ear is occluded. This will render the bone-conduction hearing thresholds improved in the normal and sensorineural hearing loss. This phenomenon will not occur with conductive hearing loss.

7. Difference limen indicates the smallest detectable change. This can be related to intensity or frequency.

8. The concept that the round window is exposed to the external auditory canal and the oval window is protected is defined as sonoinversion.

9. Interaural attenuation for air conduction is 40-50 dB and for bone conduction is 0 dB.

10. Usual norms:

a. 4-month-old baby: responds to mother's sounds

b. 6-month-old baby: turns head to a source of sound located 3-4 ft away

c. 24-months-old baby: responds to some words and perhaps phrases; able to obtain thresholds with play audiometry

d. 40-month-old baby: is able to perform a conventional audiogram if cooperative.

4 11. Any conductive hearing loss greater than 40 dB suggests ossicular problems.

Tuning Fork Tests

Every otologic patient should be tested with a tuning fork before an audiogram is performed. If the responses to the tuning fork do not agree with the audiogram, the situation should be resolved with repeated testing and repeated audiometric studies. Clinically, the most useful fork is the 512. A negative Rinne response to the 512 fork indicates a 25-30 dB or greater conductive hearing loss. A 256 fork may be felt rather than heard. Besides, ambient noises are also in the low frequencies, around 250 cps. When striking the fork, it is essential to strike it gently to avoid overtones. The maximum output of a tuning fork is about 60 dB.

Weber Test

In Weber's test the tuning fork is placed on a midline structure on the skull. The forehead, the nasal bone, and the incisor teeth are favorable sites. In a normal individual the tone is heard symmetrically in both ears. In a person with a sensorineural hearing loss, the tone lateralizes to the opposite ear. It lateralizes to the ear with conductive hearing loss. Possible reasons for this are:

a. Less masking noise via air conduction from the environment in the ear with conductive hearing loss.

b. An abnormal conductive mechanism prevents escape of energy through the ossicular chain thus enhancing bone conduction.

Rinne Test

Rinne's test compares the loudness of the sound perceived when holding the tuning fork next to the external auditory canal with holding it against the mastoid. It is important to place the fork firmly against the mastoid (preferably near the postero-superior edge of the bony canal) and to hold the tines of the fork about 1 in. lateral to the tragus.

A negative Rinne with a 256 fork implies a conductive deficit of 15 dB or more. However, the 256 fork is not a reliable fork to use for this test. The 512 fork is the most commonly used fork. A negative Rinne with this fork implies a 25-30 dB or more conductive hearing loss. A 1024 fork would give a negative Rinne when a conductive loss is 35 or more.

Bing Test

The tuning fork is applied to the forehead and lateralization is noted when present. The external auditory meatus of one side is then occluded. The patient indicates whether the intensity of the sound has increased or whether it lateralizes to the occluded side. This is repeated with occlusion of the opposite ear.

In an ear with a normal sound-conduction mechanism (i.e. a normal ear or one with sensorineural hearing loss) occlusion of the meatus would intensify the sound or cause lateralization to that ear. An ear with a significant conductive hearing loss would have no

5 effect from occlusion of the meatus.

Gelle Test

A tuning fork is placed against the mastoid. The intensity of the sound heard is compared with various amounts of pressure applied against the tympanic membrane. An increase in pressure results in a decrease in intensity of bone conduction if the tympanic membrane and ossicular chain are mobile and intact. When ossicular discontinuity or fixation is present, there is no decrease in intensity with an increase in applied pressure.

Lewis Test

A tuning fork is placed against the mastoid. When it is no longer heard, it is placed against the tragus with gentle occlusion of the meatus. The patient is then asked if he hears the tone again. The interruption of this test is neither simple nor consistent.

Schwabach Test

Schwabach's test compares the hearing acuity of the patient with that of the tester as transmitted by a vibrating fork applied on the mastoid (assuming the tester has normal hearing).

The tuning fork can also be used to test recruitment and diplacusis between the two ears.

Audiology

The Decibel

In general, the decibelk (dB) is a measure of the intensity of a sound and may refer to either sound power or sound pressure. In the usual application, the measurement of hearing by audiometry, the decibel refers to sound pressure. Some sources have erroneously stated that 1 dB is equal to the smallest "just noticeable difference" that the ear can detectg. While this is approximately true. it would be more accurate to say that the just noticeable difference varies as a function of sound intensity. For very faint sounds, the difference must be 3 or 4 dB to be perceived while for very intense sounds the normal ear can detect changes as small as 0.3 dB. A tone that is made 10 dB more intense than another, is likely to be perceived as twice as loud.

To further understand the decibel, it should be noted that intensity is a physical attribute of sound which can be manipulated and measured with appropriate electronic equipment in a laboratory. The psychologic correlate of intensity is loudness. The sensation of loudness is related to stimulus intensity but not on a one-to-one basis. For soft sounds, a relatively small change in absolute intensity units will cause a change in loudness. However, for relatively loud sounds, it is possible to make large changes in absolute intensity units without getting a perceived change in the sensation of loudness. In terms of sound pressure, the loudnest sound that the normal ear can tolerate is about 10 million times that of the softest sound it can hear. Since the ear detects differences in loudness by ratios of pressure or power

6 rather than by actual differences, a logarithmic system employing decibels has been adopted by acoustic scientists and engineers.

Technically, the decibel can be defined as the logarithm of the ratio of two sound powers. This formula which relates intensity or sound power to decibels is:

NdB = I1/I0

where power is given in watts per square centimeter. Since it is a mathematical fact that acoustic pressures are proportional to the square root of the corresponding acoustic powers, it is possibel to derive a formula which relates changes in sound pressure to decibels. It has already been noted that for purposes of hearing measurement we usually deal with acoustic pressure. The formula relating changes in sound pressure to decibels is:

NdB = 20 log P1/P2

P1 = the greater pressure in dynes/cm2 P2 = the lesser sound pressure.

Remember that we are interested in the ratio of one pressure to another.

Suppose that we would like to know how many decibels a tone will increase if we increase the sound pressure 100-fold. The formula would be applied as follows:

NdB = 20 log 100/1

the pressure ratio P1/P2 with a 100-fold increase in pressure would be 100:1.

NdB=20LOG100=20x2=40dB.

The log of a number is the power to which the base 10 must be raised to give that number. Common log tables are available to make this determination, although when the number under discussion is 1, followed by a number of zeroes, the log of that number can be found by simple adding up the zeroes. For example, the log of 1000 = 3, the log of 10.000 = 4, etc.

Unless otherwise stated, the standard reference pressure is 0.0002 dynes/cm2. The standard reference for power is 10-16 W/cm2. When decibels are calculated using the standard reference pressure as the denominator of the pressure ratio in the decibel formula, it is customary to refer to the results as dB SPL (sound pressure level).

7 Some common sound pressure levels associated with different sounds are listed in Table 2.1.

Table 2.1. Sound Pressure Levels Associated with Different Sounds

Sound Decibels (dB SPL)

Rocket launching pad 180 Jet plane 140 Gunshot blast 140 Riveting steel tank 130 Automobile horn 120 Sandblasting 112 Woodworking shop 100 Punch press 100 Pneumatic drill 100 Boiler shop 100 Hydraulic press 100 Can manufacturing plant 100 Subway 90 Average factory 80-90 Computer card verifier 85 Noisy restaurant 80 Office tabulator 80 Busy traffic 75 Conversational speech 66 Average home 50 Quiet office 40 Soft whisper 30

Noises over 140 dB SPL may cause pain. Long exposure to noises over 90 dB SPL may eventually harm hearing.

Audiometric Reference Levels

Sound Pressure Level

Stimulus levels in pure tone audiometry may be stated with reference to sound pressure level (SPL), sensation level (SL), or hearing level (HL). From the discussion of the decibel it may be recalled that the standard reference for pressure is 0.0002 dynes/cm2 or the standard reference for power is 10-16 W/cm2. Whenever decibers are discussed in terms of the pressure standard they are given as dB SPL. A 50 dB SPL tone is 50 dB above the reference pressure, 0.0002 dynes/cm2. Occasionally, steady state industrial noise or audiometric masking noise will be specified in SPL.

8 Hearing Level

Audiometric test tones are specified in hearing level (HL) rather than SPL because the normal ear is not equally sensitive to low- and high-pitched tones. According to current standards (ANSI, 1969) it takes 39 dB more SPL for the normal ear to barely hear a 125 Hz tone than it does for it to barely hear a 1000 Hz tone. Since it is desirable to havea0dBdial reading at the point where the normal ear can just barely hear the stimulus, regardless of frequency, the audiometer has been designed to compensate for differences in hearing sensitivity as a function of frequency.

If 0 dB HL is set on the attenuator dial, the sound pressure generated by the audiometer will automatically change, whenever the frequency selection dial is rotated to select a different test frequency. Table 2-2 shows how many decibels SPL is required at each frequency to achieve 0 dB HL according to current as well as past standards.

Table 2-2. Number of Decibels at Each Frequency to Achieve 0 dB HL

Frequency Present Standard Past American Standard (Hz) (ANSI - 1969, (ASA - 1951) same as ISO, 1964) dB re 0.0002 dynes/cm2 dB re 0.0002 dynes/cm2 125 45.5 54.5 250 24.5 39.5 500 11.0 25.0 1000 6.5 16.5 1500 6.5 2000 8.5 17.0 3000 7.5 4000 9.0 15.0 6000 8.0 8000 9.5 21.0

Sensation Level

Sensation level (SL) is another way to refer to stimulus intensity. Its reference is the threshold of the individual being tested. Thus, 30 dB SL means 30 dB above the individual's threshold for test stimulus, whether it be tone or some other type of sound.

The term SL often is used to specify the level at which speech discrimination tests are administered. For instance, if an individual's speech reception threshold is 40 dB HL, a speech discrimination test administered at the 30 dB sensation level will be given at a hearing level (HL) of 70 dB. If his speech reception threshold was 10 dB HL, the speech discrimination test would have to be given at the 40 dB hearing level to meet the condition of a 30 dB SL presentation.

The SISI test, which employs pure tones, is usually administered at the 20 dB sensation level.

9 Summary

Zero decibels SPL is equivalent to a sound pressure level of 0.0002 dynes/cm2; zero dB intensity level is equivalent to 10-16 W/cm2.

Zero decibels HL (audiometric zero) has different sound pressures for different frequencies. This is because the normal ear requires less sound pressure to make a tone audible in the middle frequencies than in the very low or very high frequencies. For example, zero dB HL for 250 Hz is 24.5 dB above 0.0002 dynes/cm2 (24.5 dB SPL), while zero dB HL for 2000 Hz is 8.5 dB above 0.0002 dynes/cm2 (8.5 dB SPL). To simplify the appearance of an audiometric curve, the audiometer is set such that zero dB for each frequency does not generate zero dB SPL (0.0002 dynes/cm2) but produces the necessary energy to be just audible to the normal subject. Hence, the zero dB on the audiometric dial is not zero dB SPL or 0.0002 dynes/cm2 but rather the threshold of normal subjects. For example, a patient whose threshold at 500 Hz is 30 dB has a threshold that is 30 dB higher than that of normal subjects at 500 Hz but not 30 dB higher than 0.0002 dynes/cm2.

Sensation level (SL) for auditory stimulus is based on the individual's threshold for that stimulus whether the hearing is normal or impaired. The 20 dB SL for a 500 Hz tone in a person who has an audiometric threshold of 50 dB HL for the 500 Hz tone is 70 dB HL.

Review of Standard Audiometric Test Battery

There are several standard test procedures included in the audiometric test battery, all of which provide the otolaryngologist with valuable information regarding the integrity of the ear and the hearing mechanism. A brief description of the standard audiometric test battery follows.

1. Standard pure tone air-conduction and bone-conduction testing provides information regarding the nature and degree or severity or both of hearing loss. It can determine whether the hearing loss is conductive if an air-bone gap is present, or sensorineural if there is no evidence of an air-bone gap. The configuration or shape of the hearing loss can be classified from these results, i.e. flat, low frequency, or high-frequency hearing loss.

2. Speech reception threshold (SRT) and speech discrimination testing (SD) testing may be performed using live-voice or tape-recorded presentation of standard spondee word lists (Table 2-3) for SRT, and standard phonetically balanced word lists (Table 2-4) for SD testing. The SRT is one means of determining the reliability of pure tone test results, since the pure tone average(s) should coincide with SRT(s). The speech discrimination score provides information about the clarity of speech stimuli at loudness levels relatively comfortable to the listener. If phonemic regression or presbyacusis is evident, or if the pure tone configuration indicates hearing loss (especially in the high frequencies), speech discimination scores may be poor.

10 Table 2-3. Adult Spondee Word (Familiarization) List

airplane, armchair, baseball, birthday, cowboy, daybreak, doormat, drawbridge, duckpond, eardrum, farewell, grandson, greyhound, hardware, headlight, horseshoe, hotdog, hothouse, iseberg, inkwell, mousetrap, mushroom, northwest, oatmeal, padlock, pancake, playground, railroad, schoolboy, sidewalk, stairway, sunset, toothbrush, whitewash, woodwork, workshop.

Table 2-4. Adult Phonetically Balanced Word List (Sample)

CID 1A: an, yard, carve, us, day, toe, felt, stove, hunt, ran, knees, not, new, low, owl, it, she, high, there, earn, twins, could, what, bathe, ace, you, as, wet, chew, see, deaf, them, give, true, isle, or, law, me, none, jam, poor, him, skin, east, thing, dad, up, bells, wire, ache.

CID 2A: your, bin, way, chest, then, ease, smart, gave, pew, ice, odd, knee, move, now, jaw, one, hit, send, else, tear, does, too, cap, with, air, and, young, cars, tree, dumb, that, die, show, hurt, own, key, oak, new, live, off, ill, rooms, ham, star, eat, thin, flat, well, by, ail.

3. Tympanometry, which will be discussed in greater detail in a later chapter, is an objective test used to indicate the integrity of the middle ear system. There are three basic tests performed:

a. The tympanogram is a graphic representation of the function of the tympanic membrane and middle ear system. It will indicate a type A (normal) tympanogram if the tympanic membrane and ossicles are intact and if there is no evidence of middle ear effusion. The type B (flat) tympanogram can indicate the presence of middle ear effusion or a tympanic membrane perforation. A type C (negative-pressure) tympanogram will show the degree of negative pressure present in the middle ear, which may indicate eustachian tube dysfunction.

b. Stapedial reflex testing is performed to show the hearing level at which the stapedius muscle will contract, changing the impedance of the middle ear. The results of this test may indicate normal function, absence of the reflexes due to middle ear pathology, reflexes at levels higher than normal (hearing loss), or reflexes at levels lower than normal (possible recruitment with hearing loss). Other stapedial (acoustic) reflex tests may be performed to determine the presence of cochlear vs. retrocochlear hearing loss, such as ipsilateral reflex testing and acoustic reflex decay testing.

c. Eustachian tube testing may be performed in the presence of an intact tympanic membrane or with perforated tympanic membranes and myringotomy tubes. The most common test used with perforated tympanic membranes or myringotomy tubes is the swallow test, by which pressure equalization should occur with normal eustachian tube function. When there is an intact tympanic membrane, the presence of a type C (negative pressure) tympanogram is a good indication of the presence of eustachian tube dysfunction.

The above tests are part of the standard audiometric test battery and can provide the otolaryngologist with reliable information in a relatively short period of time. Further discussion of the implications of these tests will appear later in this chapter, and in other

11 chapter.

Special Audiometric Tests

Special audiometric tests are performed to provide information over and above standard pure tone audiometry. These special tests provide "differential diagnosis" regarding cochlear vs. retrocochlear hearing loss, thereby providing the site of the lesion. The following tests are usually performed as a battery, not individually.

Bekesy's Audiometry

Thresholds are obtained automatically using pulsed and continuous tones. The audiometer automatically sweeps across the frequency ranges while the patient controls the intensity of the pure tones with a switch, attempting to maintain threshold. Thresholds are recorded on a graph. The pulsed and continuous tone threshold graphs are compared as indicated by five types of configurations.

Type I

Pulsed and continuous tracings interweave with each other across all frequencies; associated with normal/conductive hearing loss.

Type II

Pulsed and continuous tracings interweave through approximately 1000 Hz, but then the continuous tracing drops to about 20 dB poorer below the pulsed tracing. Associated wtih cochlear site of lesion.

Type III

Pulsed and continuous tracings interweave in the low frequencies only, then the continuous tracing drops to more than 20 dB poorer below the pulsed traing. The continuous tracing may exceed the limits of the audiometer. Associated with retrocochlear site of lesion.

Type IV

Pulsed and continuous tracings never interweave, with the continuous tracing always poorer (to audiometer limits) than the pulsed tracing. Associated with retrocochlear lesion.

Type V

Pulsed and continuous tracings are separated, with the continuous tracing better than the pulsed tracing; associated with nonorganic or functional hearing loss.

Tone Decay Testing

This testing is utilized to determine the presence of retrocochlear hearing loss. Continuous pure tone stimuli are used to measure adaptation at threshold. With tone decay

12 present, it becomes necessary to increase the intensity of the stimulus to keep it audible at threshold. Persons with retrocochlear lesions exhibit rapid tone decay, 30 dB of tone decay in 1 minute being considered marked decay. Several tests are used, including the Carhart's and the Rosenberg's tests. In these tests, the difference between threshold and the level at which the patient finally heard the tone for a full 1 minute indicates the amount of tone decay.

Suprathreshold Adaptation Test (STAT)

The STAT is similar in nature to conventional tone decay tests, but is performed at 110 dB SPL at 500, 1000, and 2000 Hz. The premise that symptoms of abnormal tone decay first appear at the highest testable sound intensities is the basis for the STAT. If the patient can hear the tone for a full 1 minute the test is negative for retrocochlear pathology. If he cannot hold the tone for 1 minute, the results are considered positive for the presence of a retrocochlear lesion.

Performance:Intensity Function for Phonetically Balanced Words (PIPB Function)

In this test, PB word lists are presented in 10-20 dB steps above the SRT. Scores should improve with increases in intensity; PB scores will improve until a maximum score or PB max is obtained, at which point the score will not change significantly with further increases in intensity. Scores are not expected to change more than 19% once PB max is reached. However, when presentation levels are increased, the individual with a retrocochlear lesion will show reduced speech discrimination scores (greater than 20% change) after PB max is obtained. This is termed "rollover" phenomenon. When scores rollover exactly 20% the results are questionable.

Short Increment Sensitivity Index (SISI)

The SISI is a test which assesses the ability of an individual to detect 1 dB intensity increments at 20 dB SL. It is based on the difference limen for intensity. Persons with a cochlear site of lesion are able to detect a 1 dB increment. A continuous pure tone is presented monaurally at 20 dB SL in regard to pure tone threshold at that frequency. Periodically, 1 dB increments are superimposed on the continuous tones. The patient signals every time he hears the increment. Normal individuals and those with retrocochlear lesions are not able to detect the changes in intensity. Those with cochlear hearing loss can easily detect the increments, showing high scores on this test.

0-30% detection: normal or noncochlear (negative results) 30-60% detection: questionable results 60% detection or better: cochlear pathology (positive results).

Alternate Binaural Loudness Balance (ABLB)

This test for recruitment is generally performed when one ear is within normal limits and the impaired ear is at least 20 dB poorer at the test frequency. The patient indicates when a presented stimulus sounds equally loud to both ears. Recruitment is an abnormal growth in loudness, and is evident when the perceived loudness of the signal grows more rapidly in the affected ear, than in the normal ear. Recruitment is usually manifested in pathologies

13 associated with acoustic trauma, ototoxic drugs, Ménière's disease, and indicates cochlear pathology.

1. No recruitment: Between ears, equal loudness at equal sensation levels (SL).

2. Complete recruitment: Between ears, equal loudness at equal hearing levels (HL).

3. Partial recruitment: Between ears, equal loudness occurs in-between the above.

4. Derecruitment: Equal loudness occurs with 10 dB or greater sensation levels (SL) in the poor ear than in the good ear: retrocochlear lesion.

5. Interpretation: Results are reported as (a) normal or cochlear, (b) retrocochlear, or (c) questionable. If performance climbs to a maximum and then remains there or declines less than 20% as intensity is increased above the level yielding the maximum percentage correct, results are reported as normal or cochlear. If performance declines more than 20% when intensity is raised above the level yielding maximum performance, results are reported as retrocochlear. Questionable findings are indicated in those subjects who rollover exactly 20%.

Glycerol Test for Ménière's Disease

Pretest restrictions: NPO for 6 hours before test, no sedatives, tranquilizers, strong analgesics, antivertiginous medications for 48 hours before the test. Caution should be exercised in patients with cardiovascular disorders, diabetes, and gastrectomy surgery.

Dosage: 1.2 mL of 95% glycerin per kilogram in an equal volume of saline with several drops of lemon juice. Audiologic testing consists of pure tones (AC and BC), SRT, and PB-max (NPO during test).

1. Preingestion of glycerol.

2. One hour postingestion.

3. Two hours postingestion.

4. Three hours postingestion.

Side Effects

1. Thirst (usual).

2. Headache (23%).

3. Nausea (37%).

4. Emesis (5%).

5. Drowsiness.

14 Positive Test

1. Fifteen decibels or more improvement at any one frequency or 10 dB or more improvement at two or more frequencies between 250 Hz and 2000 Hz.

2. Twelve percent or more improvement in PB max.

3. Ten decibels or more improvement in SRT.

The test is inaccurate for minimal loss.

Functional Hearing Loss

Functional hearing loss, also called nonorganic hearing loss, psychogenic hearing loss, malingering, and pseudohypoacusis, describes a hearing loss which has no organic etiology. When a patient exaggerates a hearing loss, several indications will be present. It is necessary for the audiologist to be aware of the situation and attempt to determine the true hearing level.

Functional hearing loss becomes evident when the individual does not respond consistently to pure tones, when pure tone averages do not agree with speech reception thresholds, when the individual may use half-word responses for SRTs, and when the individual may use rhyming word responses during speech discrimination testing, among other inconsistencies. Very often a functional hearing loss is presented only in one ear. A functional hearing loss also may be exaggeration or overlay of a true organic hearing loss. It is not always in the realm of the audiologist's or otolaryngologist's expertise to determine the cause for feigning a hearing loss, nor should they attempt to analyze the cause.

The following tests are used for determining the true hearing level.

Stenger's Test

Stenger's test is used when one ear presents a functional component. It will indicate the presence of functional hearing loss and approximate the true threshold of hearing. The basis for the Stenger test is the theory that when two tones of identical frequency are sounded simultaneously in each ear, an individual with normal hearing or equal bilateral hearing loss will be aware of only the louder tone.

Present a tone at 5 dB SL in the normal ear, and present the same tone to the suspected functional ear. Hold the intensity constant in the normal ear. Continuously increase the intensity to the suspected ear. The patient will continue to respond as long as he hears the tone if there is true hearing loss. If the suspected ear has a functional hearing loss, the tone will be heard in the "poor" ear as intensity is increased. Then he will stop responding to the tone, since he "shouldn't" be hearing in that ear. The intensity at which he ceases to respond is close to threshold.

The Stenger's test also may be performed with speech stimuli in the same manner as with pure tones.

15 Lombard's Test

Lombard's test is based on the principle that a speaker unconsciously tends to raise his voice when he is speaking in a noisy environment so that he may hear himself speak. Masking noise is introduced to the patient under headphones while he reads aloud. In a true organic hearing loss, the individual will not raise his voice because he will not hear the masking. With a functional hearing loss, he will increase the volume of his voice as the intensity of the masking increases in the affected ear. This may be performed on unilateral or bilateral functional hearing loss.

The Doerfler-Stewart Test

This test is used for detecting bilateral functional hearing loss. Spondee words are presented binaurally through headphones in the presence of masking noise. Normal individuals and those with true organic hearing loss can repeat spondee words when masking noise levels equal or slightly exceed the levels of speech signals. Those with functional loss may cease responding when the intensity of the masking noise is 10-15 dB less than the level of the spondees. Once, this was considered a strong test of functional hearing loss.

Delayed Auditory Feedback (DAF)

The DAF test uses a 0.2 second delay of the patient's voice when reading aloud. This slight delay will cause a disruption of fluency. The subject reads aloud into a microphone attached to a tape recorder. The recorder plays back the discourse through headphones on a 0.2 second delay. The intensity of the played-back speech is increased until the individual begins to speak in dysfluencies (since he can hear himself delayed). The level at which the dysfluencies begin may be considered close to SRT.

Evoked Response Audiometry (ERA)

The ERA test is a truly objective measure of hearing, based on transient changes in the electric activities of the central nervous system in the presence of sound stimulation. This evaluation requires no voluntary response from the patient, and will be discussed in greater deatil in a later chapter.

Stapedial Reflex Testing

This is another objective test which may be helpful in estimating pure tone thresholds based on the levels at which the acoustic reflex is present compared to norms for normal hearing reflex thresholds.

Electrodermal Audiometry

Electrodermal audiometry is a test which used a slight electric shock to condition a reflex when pure tones were presented. Because of the questionable nature and unpleasantness of this method, it is rarely, if ever, used at this time.

16 Acoustic Trauma and Noise-Induced Hearing Loss

Temporary Threshold Shift (TTS)

This phenomenon is indicated by the human ear's ability to recover from brief exposure to loud sounds. When the ear is exposed to such sounds as machinery, explosions, and the like, the hearing threshold levels become poorer because of auditory fatigue. The recovery of normal thresholds is usually complete and occurs within 1 hour to 2 weeks, depending on the intensity of the sound source and on the length of noise exposure. This is a temporary threshold shift. The greatest shift is for tones about one-half octave above the exposure tone, but other higher frequencies may be affected as well. Usually low frequency hearing is not affected. This also has been shown in data showing that when the maximum energy is the in the low frequencies, the TTS is less than when maximum sound energy is in the higher frequencies.

If the exposure is intermittent, the TTS is less. With more constant exposure, TTS becomes greater and may take more time to recover. This phenomenon applies to periodic exposure to loud sources.

Permanent Threshold Shift (PTS)

A PTS occurs over time in individuals who are exposed to high levels of noise without ear protection, and results in permanent (sensorineural) hearing loss. This shift in hearing depends upon the intensity and duration of exposure.

It is important to make the distinction between acoustic trauma and noise-induced hearing loss. The former refers to a sudden permanent or temporary hearing loss related to a brief exposure to an explosion-type sound. Noise-induced hearing loss results from exposure to high levels of noise for an extended period. The audiometric evaluations indicate a similar pure tone configuration, so a complete case history is imperative. However, noise-induced hearing loss is relatively permanent in nature.

The typical audiometric configuration in noise-induced hearing loss in the early stages shows normal hearing at 250-2000 Hz with a dip at 4000 Hz of varying degree, returning to normal in the higher frequencies. As this hearing loss progresses with more exposure to high noise levels, the frequencies surrounding 4000 Hz become more involved in the hearing loss, eventually resulting in a "ski slope" audiometric configuration.

Periodic hearing evaluations should be performed on those regularly exposed to high levels of noise, and on those who are no longer working in noise. However, a respite from noise exposure (at least 14 hours for industrial hearing screenings) is necessary to allow for recovery of any TTS overlay on a PTS.

OSHA Damage Risk Criteria

OSHA has developed standards for permissible durations of exposure without ear protection. These standards are printed in Table 2-5. However, they may be revised following more research from OSHA, whose industrial noise regulations recently have been in a state

17 of flux.

Table 2-5. OSHA Permissible Noise Exposure Levels

Duration/day (hr) Sound Level (dBA)

890 692 495 397 2 100 1-1.5 102 1 105 0.5 110 0.25 or less 115.

It is known that noise-induced hearing loss can be prevented by reducing levels of noise exposure or time of exposure and by the use of personal ear protection, in the form of earmuffs or earplugs. Various manufacturers have developed disposable, reusable, custom- shaped and standard sized earplugs and more efficient earmuffs. These developments were made to encourage more use of personal ear protection by workers, but the number of individuals who prefer not to wear ear protection are staggering. Therefore, despite OSHA regulations and cooperation from employers regarding provision of ear protection and reevaluating hearing status regularly, many persons will still exhibit noise-induced hearing loss in the future.

Ear Protectors (Table 2-6)

Table 2-6. Attenuation in dB in the Various Frequencies (Hz)

Protection Type 250 500 1000 2000 3000 4000

Fluid sealed muffs 28 38 39 41 44 47 V-51R plug 11 13 19 27 30 25 Glass down 11 13 17 29 34 35 Waxed cotton 10 12 16 27 31 32 Dry cotton 348121412.

Four Thousand Hertz Dip (8-10 mm Region of the Cochlear Duct)

The 4000 Hz sensorineural dip is one of the principal audiometric features of a hearing loss resulting from excessive noise. There are basically three theories to explin this. One hypothesis is that the area of the organ of Corti responsive to 4000 Hz is highly susceptible to damage, possibly as a result of vascular insufficiency. The second hypothesis believes that the resonance characteristics of the ear canal produce the 4 kHz notch. The third view contends that the mechanical stress on the basilar membrane is excessive in the 4000 Hz region because of the mechanics of cochlear action. This latter explanation is based on the

18 asymmetric distribution of the amplitude of displacement of the basilar membrane. It is believed that the stress is due to the acceleration of the basilar membrane during stimulation. Acceleration of the basilar membrane is greatest at the basal end and becomes progressively less at the apical end. Greater losses for frequencies above 4000 Hz do not occur because there is less auditory sensitivity in that region. The mechanical hypothesis is preferred by a number of investigators since there is evidence from auditory fatigue studies that stimulation by a given level tone caused no greater auditory fatigue at 4000 Hz than at 1500 Hz. It also has been found that the recovery rate for 4000 Hz did not proceed less rapidly than at other frequencies.

Hearing Handicap

Hearing loss, and therefore the degree of hearing loss, may be described in several ways. It may be described in relation to decibels of hearing loss, and it may be described subjectively, i.e. mild, moderate, severe, or profound. It also may be described in relation to how well the hearing impaired individual can communicate in the everyday world. Table 2-7 ASHA, 1981) shows several scales in common use for describing the degree of hearing loss in relation to the decibel levels involved.

Table 2-7. Scale of Hearing Impairment

Average Hearing Threshold Level in dB Hearing Loss Label (re: 1969 ANSI)

10-15 Normal hearing 16-25 Slight hearing loss 26-40 Mild hearing loss 41-55 Moderate hearing loss 56-70 Moderately severe hearing loss 71-90 Severe hearing loss 91 + Profound hearing loss.

Evidently the decibel levels and descriptors are not in agreement from one scale to the next. Hence, one particular audiogram may be described any number of ways using any scale above. The main point in describing hearing loss is consistency. The individual otolaryngologist or audiologist must be consistent in describing audiometric results in the same manner from one time to the next, and from one patient to the next. Once a pattern has been developed, it is important to maintain this same scale to keep consistent records. It is also helpful to describe the configuration of the audiogram, since this information can be useful, especially when looking at SRTs and speech discrimination scores.

One consistent, however controversial, method of measuring hearing impairment is the AAO percentage of hearing impairment formula, reproduced and explained in Table 2-8. This formula is currently acceptable for use in insurance and compensation claims. Controversy may arise because of the correction for age over 40 years, since it appears to assume a certain degree of hearing loss after that age. It has been maintained that the individual physician may choose to eliminate this section of the formula and only use the absolute hearing loss figures when describing the percent of hearing impairment.

19 Table 2.8. AAO Formula for Calculating Percentage of Hearing Impairment

The following formula is used for calculating the percentage of hearing impairment:

... dB HL Pure tone average (500, 1000, 2000, 3000 Hz) - 26 AAO limits ... dB HL Corrected hearing loss x 1.5 ... % Percent hearing impairment - calculated for each ear separately. Then:

Better ear%x5=...+Poorer ear%=.../6=...%forbinaural loss.

If person is 40 years of age or less, it is not necessary to correct the above percentages for age. If over 40 years of age, the following correction formula is used:

(Age - 40) x 0.5 = ... Correction factor in dB (0.5 dB/yr over 40 years old).

Then:

... dB HL Corrected hearing loss (from initial calculation). - ... dB Correction factor = ... dB Adjusted hearing level x 1.5 = ... % Adjusted percent hearing impairment - calculated for each ear separately. Then:

Better ear%x5=...+Poorer ear%=.../6=...%forbinaural loss.

It is important to note at this point that the former scales indicate descriptors of the hearing loss in question and may be more useful from a (re)habilitative point of view insofar as the estimation of communication ability. The AAO percentage of hearing impairment formula represents an absolute number value of the hearing loss. Therefore, in certain instances one method would be more useful than the other.

Testing Infants and Children

Until age 2 years the human infant does not respond to sound stimuli in the same manner as the older child or adult. The human infant, although it may have normal hearing, does not respond to the softest sounds it can hear, or to the softest sounds to which the adult can respond. Much research has been conducted to obtain normative data, as reproduced below. It is possible to test infants in the sound field using the data present. Infant localizations to sound sources also mature.

Attempts have been made at maintaining infant high-risk registers in hospitals for identifying neonates at risk for hearing loss. Difficulties arise with identifying and testing large numbers of at-risk infants before discharge. Methods of weeding out those infants who must be screened are still being developed. The use of portable auditory screeners in the

20 nursery is n ow being eliminated with the further development of brain stem evoked response (BSER) audiometry. This relatively quick and efficient test can provide full information regarding the neonate's hearing, and will be discussed in detail in a later chapter. The largest problem with the high-risk registry is follow-up. It is imperative that once an infant has been identifid as hearing impaired or has failed an initial hearing screen, he should be reevaluated at a later date for more complete results and prognosis for amplification as soon as possible.

The main purpose of the high risk register and other similar early screening programs is to provide early identification of hearing loss for early amplification. The later the child is identified as being hearing impaired, the later he will be amplified. This results in later language development. It is vital to the child's early development that sound stimulation be provided in the form of amplification (or other appropriate method) as soon as possible.

Hearing Aids

After any patient has been identified as having a hearing loss and as a candidate for amplification, the otolaryngologist may perform the following functions in counseling the patient:

1. The physician may describe the audiometric results (pure tones, SRT, speech discrimination scores relative to normal communication), and the patient's prognosis for success with amplification.

2. The physician may discuss binaural vs. monaural amplification with the prospective candidate. Very often the financial aspect may prevent binaural amplification. In other situations, binaural hearing aids are necessary, especially when they involve infants and children.

3. The patient may query regarding a behind-the-ear vs. an in-the-ear fitting. In many cases, an in-the-ear hearing aid would be most appropriate, but most often sa behind-the-ear hearing aid is chosen. Discussing this may be left to the audiologist or hearing aid dispenser involved, whose experience may dictate the type of fitting to be attempted.

4. As a general rule, the better ear would be fitted with a hearing aid, or at least the ear with the better speech discrimination score. This rule is not steadfast, and may change with different patient situations and needs.

Basically, a hearing aid consists of three parts:

1. Microphone: Changes sound energy into electrical energy.

2. Amplifier: Amplifies the converted electrical energy.

3. Receiver: Converts the amplified electrical energy back into sound energy.

The hearing aid's main function is to amplify all sounds. It makes things louder, not necessarily clearer. Therefore, it is necessary for the new hearing aid user to experience an adjustment period with this new hearing aid. The wearer must become accustomed to listening

21 again, and to hearing the new sounds which the hearing aid is amplifying. He needs to weigh his expectations for amplification with the actual result he has achieved. It is important that the otolaryngologist and audiologist work with the wearer cooperatively when handling and counselling regarding amplification, so that he can become comfortable with amplification.

Depending upon the nature and severity of the hearing loss, how long the patient has been hearing impaired, and the type and intensity of counseling the patient received before, during, and after evaluating hearing aids, his prognosis for successful use of amplification can be very good. More persons who previously had been told that they could not be helped by amplification are successfully wearing hearing aids. The numbers can become better with more intensive counseling and acceptance of amplification in the future.

Table 2-9. Enzymes Found in the Organ of Corti and Stria Vascularis

Succinate dehydrogenase Cytochrome oxidases Diaphorases (DPN, TPN) Lactic dehydrogenase Malic dehydrogenase Alpha-glycerophosphate-dehydrogenase Glutamate dehydrogenase.

Table 2-10. Normal Labyrinthine Fluid Values

Serum CSF Perilymph Endolymph Endolymph sac S. tymp S. vest Cochl Vest

Na 141 141 157 147 6 14.9 153 mEq/L K 5 3 3.8 10.5 171 155 8 mEq/L Cl 101 126 - - 120 120 - mEq/L Protein 7000 10-25 215 160 125 - 5200 mg% Sugar 100 70 85 92 9.5 39.4 - mg% pH 7.35 7.35 7.2 7.2 7.5 7.5 -.

Table 2-11. Electric Potentials of Ear Components

A. Endocochlear potential Scala media + 80 mV Endolymph potential Scala vestibuli + mV Resting potential Scala tympani 0 DC potential Hair cell and cortilymph - 80 mV Endolymphatic sac (+) Cells of Hensen and Claudius (-)

22 B. Action potential of the nerve.

C. Cochlear microphonics (due to stimulation of outer hair cells).

D. Summation potential (due to stimulation of inner hair cell and is more significant in higher frequencies).

(The recording of endocochlear potential and summation potential requires an intracochlear electrode while the action potential of the nerve and cochlear microphonics can be picked up with a round window electrode).

23 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 3: Electric Response Audiometry

During the past 10 years electric response audiometry (ERA), particularly brain stem audiometry, has become an important clinical tool. In this chapter the basic principles of electric response audiometry are reviewed. We then describe the various techniques emphasizing their clinical applications.

Basic Concepts of Electric Response Audiometry

The aim of electric response audiometry is to record the potentials that arise in the auditory system as a result of sound stimulation. The basic principles of recording the electric potentials from the auditory system are the same regardless of the potential that is of particular interest. The recording is made difficult by the fact that the potentials generated in the auditory system are minute in comparison with the background or electric impulses from other parts of the body (brain, heart, and muscles). The development of the average response computer has made it practical to record these potentials in the clinical setting.

The apparatus for electric response audiometry is shown in simplified block diagram in Fig. 3-1. The stimulus is an acoustic impulse of very short duration termed a click, tone pip, or tone burst. This brief stimulus produces a synchronized discharge in the auditory system. The stimulus is attenuated and then presented to the test ear through either a free-field loudspeaker or a headphone. Depending on the technique employed, the active electrode is applied to the ear lobe, mastoid prominence, ear canal, promontory, or scalp vertex. An appropriate reference electrode also is applied. The minute signal these electrodes pick up is differentially amplified first in a preamplifier and then further enlarged in an amplifier before being delivered to the averaging computer.

The average response computer consists of a series of memory units, each receiving information a fraction of a second later than the one just before it. We like to think of each point as a small calculator capable of addition and subtraction.

The computer is triggered to begin its sequential process of analysis each time a stimulus is delivered to the ear. The signal is said to be time-locked to the averager. In other words, the response repeatedly occurs in the same group of memory locations. In this way the potentials from the auditory system that singly would be impossible to identify are extracted from the background noise, which is reduced by the averaging. The averaged response is then transferred to permanent recording paper for analysis.

The basic principles for recording are the same in all electric response audiometry. The techniques vary depending upon the response to be measured.

Auditory Evoked Potentials

The most important auditory evoked potentials and their probable sites of generation are outlined in Table 3-1. In considering these responses it is important to point out that the measurements obtained from ERA methods are generally not measures of hearing per se.

1 Hearing is a perceptual process that involves the entire auditory system and cannot be measured in terms of electric responses unless those responses can be shown to relate directly directly to perception. The clinical value of ERA lies in the correlation of electric responses with auditory pathology and/or performance.

Table 3-1. Potentials Evoked in the Auditory System by Sound Stimulation, Their Probable Sites of Origin, and Typical Latencies

I. Cochlea (hair cells). Cochlear microphonic. Summating potential.

II. Auditory nerve. (eight nerve action potential (wave I) 2.0 msec.

III. Brain stem

Wave II - cochlear nucleus 3.0 msec. Wave III - superior olive 4.1 msec. Wave IV - lateral lemniscus 5.3 msec. Wave V - inferior colliculus 5.9 msec.

Frequency following response - unknown. Slow negative 10 (SN-10) - unknown 10.0 msec.

IV. Middle responses (auditory cortex). N0 - 8 to 10 msec (variable). P0 - 13 msec. Na - 22 msec. Pa - 34 msec. Nb - 44 msec.

V. Vertex potential (auditory cortex). P1 - 50 msec (variable). N1 - 90 msec. P2 - 180 msec. N2 - 250 msec.

Sustained cortical potential. Late positive component. Contigent negative variation.

Types of Electric Response Audiometry

Three techniques for recording the auditory evoked potentials have been described: electrocochleography (ECoG), auditory brain stem response audiometry (ABR), and cortical electric response audiometry. A comparison of these techniques is presented in Table 3-2.

2 Electrocochleography

Electrocochleography is the measurement of the potentials arising within the cochlea and the auditory nerve: cochlear microphonic, summating potential, and eight nerve action potential. In most cases a needle electrode is placed through the tympanic membrane onto the bone of the promontory to make these recordings.

Table 3-2. Comparison of Techniques of Electric Response Audiometry

Technique Electrode Effect of Portion of Reliability Anesthesia Auditory System Tested

Electrocochleography Promontory None Peripheral Excellent Auditory brain stem response Surface None Brain stem Good Cortical evoked response audiometry Surface Marked Entire Fair.

Electrocochleography is the most accurate of the electric response audiometric techniques by virtue of the close proximity of the electrode to the generator sites. Accuracy also is enhanced because the peripheral auditory system is unaffected by sedation or even general anesthesia.

An obvious disadvantage of this technique is the requirement for tympanic membrane penetration. Another disadvantage is that it measures only the response of the most peripheral portion of the auditory system and, therefore, cannot be equated with hearing as such. Although relatively rare, there are cases in which the cochlea and auditory nerve function normally, but brain stem or central defects produce hearing loss.

Auditory Brain Stem Response Audiometry

Auditory brain stem response audiometry utilizes surface electrodes to measure the potentials arising in the auditory nerve and brain stem structures. The active electrode is placed on the scalp vertex. , and the reference electrode is attached to the mastoid prominence of the test ear. The opposite mastoid is used as a ground. The events that occur during the first 10 msec following sound stimulation are recorded.

The advantage of auditory brain stem response audiometry is that because surface electrodes are used, anesthesia is not requird. In practice, however, either basal narcosis or anesthesia is often required in children to prevent excessive movement which interferes with accurate recordings. Auditory brain stem response audiometry, like electrocochleography, is not influenced by basal narcosis or general anesthesia.

Cortical Electric Response Audiometry

Cortical electric response audiometry involves the measurement of the potentials that arise in the auditory system above the brain st em (the middle and slow potentials). The electrode configuration is the same as for auditory brain stem response audiometry.

3 An advantage of cortical electric response audiometry is that in measuring the most central responses, the entire auditory mechanism is tested. Responses can thus be best equated with clinical hearing. This is particularly important when there is a question of a central disturbance.

A major disadvantage of cortical electric response audiometry is that the potentials also are affected by sleep and sedation. Because of these factors, cortical electric response audiometry is more difficult to perform in a clinical setting.

Electrocochleography

Stimulation Techniques

The stimulus most commonly used in electrocochleography has been wide-band click stimulus. Acoustically the click comprises a large number of frequencies which stimulate the entire cochlea. With a flat hearing loss, the click is a good predictor of the audiometric threshold. With sloping hearing losses, however, one cannot predict the type of audiogram using click stimuli.

Eggermont has used tone bursts for electrocochleography. Frequency-specific tone bursts are more accurate indicators of hearing levels at different frequencies and predict the behavioral audiogram quite accurately.

Recording Techniques

A standard Teflon insulated electromyographic recording needle is positioned onto thebone of the promontory after induction of anesthesia of the tympanic membrane by means of iontophoresis or topical phenol application. Responses are filtered below 30 Hz and above 3200 Hz. The computer is set to measure over a 10 msec window.

Measurable Potentials

Electrocochleography is a measure of the potentials arising within the cochlea and the auditory nerve: cochlear microphonics, summating potential, and eight nerve action potential.

Cochlear Microphonic

The source of the cochlear microphonic is the hair-bearing surface of the hair cells. Its onset is immediate and it mimics the wave form of the acoustic stimulus. Because the response recorded from the promontory is diffuse and gives no definite information regarding specific populations of hair cells, most investigators do not find the cochlear microphonic clinically useful.

Gibson and Beagley are an exception and have used the cochlear microphonic to aid in differentiation of cochlear from retrocochlear lesions. They find a tendency toward a reduction in microphonics in cochlear lesions, whereas in acoustic tumors the cochlear microphonic is often normal.

4 The eight nerve action potential is of primary interest in electrocochleography. This can be recorded free of the interfering cochlear microphonic by cancelling the microphonic by alternating the phase of the click or tone burst stimulus.

Summating Potential

The summating potential also is generated by the hair cells and is a direct current shift of the baseline of the recording, which is almost always negative for all frequencies and intensity levels in man (Fig. 3-2). This potential is thought to represent asymmetry in the basilar movement resulting from a pressure difference between the scala tympani and the scala vestibuli during sound stimulation. The source of this dc shift is also the hair cells. As we shall see later, this potential may be a means of studying hair cells in Ménière's disease and other cochlear disorders.

Since the summating potential appears superimposed upon the eight nerve action potential, its measurement is sometimes difficult. One technique for separating the summating potential from the eight nerve action potential is to increase the click rate. As the rate of the click is increased, the eight nerve action potential diminishes because the individual neurons do not have time to recover from their refractory period to again respond to the new stimulus. The summating potential is unaffected by click rate. A recording is first done at a low click rate and the response, which comprises both the summating potential and the eight nerve action potential, is stored in computer. A second recording is then done with a high click rate. The response obtained represents primarily the summating potential and is used as a measure of that response. The second response can then be subtracted from the first response in the computer and the derived response will represent primarily the eight nerve action potential devoid of the contaminating summating potential.

Compound Action Potential

The eight nerve action potential is the averaged response of the discharge pattern of many auditory neurons. Cochlear dynamics which influence the shape of the compound action potential are extremely complex and beyond the scope of this discussion. The reader is referred to Eggermont's chaper on electrocochleography in the Handbook of Sensory Physiology for a current review of this subject.

In addition to the normal compound action potential, Portmann and Aran have described four types of electrocochleographic response in patients with sensorineural hearing impairment: dissociated, recruiting, broad, and abnormal. Only the normal response will be described here.

Normal response. In patients with normal hearing an action potentical can be elicited to within 5-10 dB of the patient's behavioral threshold in most cases. At high intensity the potential is large, consistent, easily recordable, and reproducible. Action potentials are described by three parameters: latency, amplitude, and wave form.

Latency is defined as the time interval from the onset of the click to the maximal negative deflection in the action potential. Latency normally decreases systematically from approximately 4 msec at threshold to 1.5 msec at high intensity. Amplitude, on the other

5 hand, characteristically increases in two steps. There is a gradual rise to the level of approximately 40-50 dB HL, where there is a plateau, and then a second more rapid increase in amplitude above that level.

By convention, latency and amplitude (as a percentage of maximal amplitude) are plotted in relation to stimulus intensity. The maximal amplitude and representative wave forms are plotted on the recording (Fig. 3-3).

Clinical Applications of Electrocochleography

There are three clinical uses for electrocohleography: threshold testing, the study of Ménière's disease, and the study of acoustic neurinomas.

Threshold Testing

Electrocochleography is the most accurate of the objective audiometric tests. Thresholds to the click are an indication of the audiometric threshold in the 3000-4000 Hz range. The electrocochleographic threshold predicts the behavioral threshold to within 5-10 dB at this frequency to almost all cases. As stated before, however, one cannot predict the audiogram using clicks only.

There is a much better correlation to the subjective audiogram using tone bursts rather than clicks. The best correlation is the frequencies of 1, 2, and 4 kHz, but correlation remains excellent at 500 and 8000 Hz.

The disadvantage of using electrocochleography for threshold determination is the necessity for transtympanic needle placement. At the Otologic Medical Group, Inc, we currently use auditory brain stem response audiometry for threshold determination.

Ménière's Disease

The summating potential and the compound action potential are of interest in the study of Ménière's disease.

Summating potential. Eggermont has found an increased negative summating potential during periods of hearing loss in the fluctuant hearing stage of Ménière's disease. He attributes this findings to either a mechanical displacement of the basilar membrane, which causes nonlinearities in its movement as a result of the presumed endolymphatic hydrops, or a metabolic disturbance resulting in a larger endolymphatic potential. As fixed hearing loss develops, the summating potential decreases. This indicates a loss of hair cells. Measurement of the summating potential may, therefore, be an indication of reversibility of the hearing impairment in Ménière's disease.

Compound action potential. Compound action potentials in Ménière's disease are generally of the broad type, most likely because of the contribution of a large negative summating potential.

6 In approximately 50% of the patients with Ménière's disease whom we studied, a distinctive type of eight nerve action potential was found characterized by a tendency to form multiple negative responses. We have not seen this type of response in other types of sensorineural hearing loss, and this may be a means of distinguishing endolymphatic hydrops.

Acoustic neurinomas. The potential of most interest in acoustic neuroma study is the compound action potential. Gibson and Beagley also have studied the cochlear microphonic as previously mentioned.

The compound action potential in acoustic neuromas is much broader than the normal potential. In our study by electrocochleography of 50 patients with acoustic neuromas we found an abnormal action potential in 85%.

As observed in the following section, brain stem audiometry is a more accurate predictor of acoustic tumors, and we use it exclusively for this problem at the present time.

Future applications of electrocochleography. Because of the necessity of penetrating the tympanic membrane for electrocochleography, auditory brain stem response audiometry has replaced it in most clinics. Threshold testing is nearly as accurate with auditory brain stem response audiometry as with electrocochleography. Auditory brain stem response audiometry is a more accurate predictor of retrocochlear pathology than is electrocochleography.

The future of electrocochleography lies in the study of cochlear and eight nerve physiology and pathophysiology. Changes in cochlear microphonics and summating potentials are an indication of hair cell disease. As outlined above, study of the summating potential and compound action potential are means of assessing the state of the end organ in Ménière's disease.

Moffat has reported changes in these potentials during glycerol dehydration in patients with Ménière's disease. Gibson, Ramsden, and Moffat also have demonstrated changes in these potentials with the administration of intravenous vasodilators. Electrocochleography is, therefore, a powerful new tool in the study of cochlear disease which will have great future application.

The disadvantage of electrocochleography is the necessity for transtympanic needle electrode placement. Because of this, surface recording techniques have become much more popular in the USA.

Auditory Brain Stem Response Audiometry

Stimulation Techniques

As in electrocochleography, the stimulus most commonly used for auditory brain stem response audiometry is a wide band click stimulus. This stimulus presents the same limitations in brain stem audiometry as in electrocochleography in that the entire cochlea is stimulated, and one cannot predict the audiogram except in cases of flat hearing impairment.

7 The majority of sensorineural losses are sloping with the loss greater in the higher frequencies. Errors, therefore, might occur in predicting a more severe loss than is actually present because of preservation of low tone hearing.

Relatively frequency-specific stimuli (tone bursts, tone pips, filtered clicks) may also be used to elicit the brain stem responses. These stimuli give more frequency-specific information regarding the cochlea and may be used to estimate audiometric thresholds as described later.

The addition of high-pass noise with various cutoff frequencies simultaneously with click stimulation is a means of assessing contributions from different areas of the cochlea. With this technique a good estimation of the audiogram can be made. This technique is detailed below.

Recording Techniques

Standard electroencephalographic disk electrodes are attached to the vertex and both mastoids of the patients to be tested. The vertex electrode is the active lead, with the mastoid on the stimulated side as the reference electrode and the mastoid of the unstimulated ear as the ground electrode. Band-passing of the system occurs at 30-3000 Hz with an overall amplification of 100.000. A time window of 10 msec is used.

Sedation is not used in adults or in small infants, who often sleep during the procedure. Uncooperative children are sedated as follows: 1 mL/25 lb intramuscularly of a combination of meperidine (Demerol) (25 mg), promethazine (Phenergan) (6.25 mg), and chlorpromazine (Thoraxine) (6.25 mg) per 1 mL. A maximum of 1 mL is used. Chloral hydrate (500 mg/5 mL) in an oral dose of 1-2 mL/10 lb may be used in place of the injectable medication.

Normal Brain Stem Responses

A series of seven waves may be recorded from the scalp vertex during the first 10 msec following sound stimulation. These waves are thought to represent successive synapses in the auditory pathway with wave V most likely representing the inferior colliculus. Of these various responses wave V is the one that is most consistent and is used in the clinical assessment of hearing (Fig. 3-4).

Frequency Following Responses

Similar to the cochlear microphonic response, the frequency following response follows the frequency of tonal stimulation. It is distinguished from the cochlear microphonic by its onset latency of about 6 msec. This has led to the general consensus that its origin is in the region of the inferior colliculus. Some researchers are still investigating whether or not the frequency following response could possibly be a repeated wave V of the transient brain stem response.

8 Recently Davis and Hirsh, and Suzuki and coworkers, have described another response at around 10 msec after stimulus onset. Davis and Hirsh have labeled this the SN-10 response and believe the generator is the primary auditory cortex.

The first appearance and latency of wave V are the measures most used in brain stem audiometry. Wave V latency is dependent upon stimulus intensity: as the intensity of the stimulus is increased, there is a systematic shortening of the latency from about 8.5 msec at threshold to 5.5 msec at the 60 dB hearing level.

Clinical Applications of Auditory Brain Stem Response Audiometry

There are three major clinical uses of brain stem audiometry: (1) threshold testing of infants, young children, and malingerers, (2) diagnosis of acoustic neurinomas, and (3) diagnosis of brain stem lesions.

Threshold Testing

Brain stem audiometry is used in all cases in which standard behavioral audiometric techniques fail. This technique allows identification of hearing impairment in infancy so that rehabilitation can be started. As described above, wideband click stimuli stimulate the entire cochlea, and one cannot predict the audiogram except in cases of flat hearing impairment. Despite this deficiency, this is a valuable technique for early identification of hearing loss. If an error is made, it is usually in predicting a greater hearing loss than is actually present. In either case, early rehabilitation is begun.

Kodera et al have shown good correlation between the behavioral audiogram and brain stem audiometry using tone burst stimuli. As with the electrocochleography, the correlations are better for the high frequencies than the low. Use of these stimuli better predicts the pure tone audiogram than does use of broad-band click stimuli. This technique, however, is still deficient in accurately predicting low-frequency hearing.

Some studies have shown good correlation of the frequency following responses to low-frequency hearing thresholds. The disadvantage of the use of this response is that its amplitude is very small and it is difficult to separate artifact from the response. Some researchers have questioned the area of the cochlea from which this response is initiated at moderate to high levels of stimulation. Thus, even though this response shows promise of aiding in the assessment of low-frequency hearing, may questions remain unanswered regarding its clinical applicability.

Recently we have applied a technique which involves the use of high-pass masking noise which can reasonably reconstruct the pure tone audiogram. This technique was first introduced in animal work by Teas, Eldredge, and Davis and later applied to electrocochleography by Elberling.

The High-Pass Masking Technique

Don and Eggermont, and Parker and Thornton have demonstrated that the whole of the basilar membrane contributes to the brain stem response to a broad-frequency click. The

9 technique of deriving the contribution initiated from each portion of the basilar membrane is illustrated in Fig. 3-5. In this figure the cochlea is rolled out flat and marked off in sections A through F. Section A represents the area of the cochlea whose maximum sensitivity is 8 kHz and above. Section B represents the region from 4-8 kHz. Section C represents the region from 2-4 kHz; section D, from 1-2 kHz; section E, from 0.5-1 kHz; and section F, the region below 5000 Hz.

A click stimulus presented at moderate hearing levels and above will stimulate the entire cochlea because of its broad-band nature. The brain stem response R-1, seen in line 1 of Fig. 3-5 represents the sum of brain stem activity initiated by stimulation of the whole cochlea (i.e. from sections A through F). Next, as seen in line 2, the level of continuous broad-band noise that is sufficient to desynchronize and thereby obliterate the response to the click is determined. This masked activity is denoted as MR.

After the appropriate noise level has been determined, the noise is steeply high-pass filtered at 8 kHz (the high-frequency component of the noise above 8 kHz is allowed to pass), and the clicks are presented in this noise. As seen in line 3 of Fig. 3-5, the brain stem response (R-2) obtained under these conditions results from click-synchronous activity initiated from the region below 8 kHz. The subtraction of this response, R-2, from the response obtained without any masking noise, R-1, in the computer results in the derived narrow band response, DR-1, seen in line 4. This subtraction procedure eliminates the common contributions from regions below 8 kHz (stippled area in line 4) and results in the contribution from the cochlea that was masked by the 8 kHz high-pass noise (section A).

Next the high-pass cutoff of the noise is lowered by an octave to 4 kHz, and the clicks are presented in this noise. The brain stem response is recorded, R-3, shown in the line 5 of Fig. 3-5, results from click-synchronous activity from the unmasked portion of the cochlea, that is, the region below 4 kHz. Subtraction of the response (R-3) from that obtained with the 8 kHz high-pass noise (R-2) eliminates the common contribution from the region below 4 kHz (stippled area, line 6). The response derived from this subtraction (DR-2) is initiated from the narrow band region of the cochlea that is not masked by 8 kHz high-pass noise, but was masked by the 4 kHz high-pass noise (section B). In similar fashion, by successive subtraction of the responses, one obtains the derived narrow band contribution to the brain stem response for the other sections of the cochlea. This procedure is repeated for different click intensities and in this manner the contribution from each portion of the basilar membrane at each intensity is derived.

In patients with normal hearin, contributions to the brain stem response to the click can be detected down to the 30 dB sensation level for the 8 kHz and above region and 500 kHz and below regions of the cochlea. Contributions to the brain stem response from 4, 2, and 1 kHz octave-wide regions can be detected down to at least the 10 dB sensation level.

To estimate the hearing loss at a given audiometric frequency, these data have been used to derive the following simple formula:

Xf = LPf - LNf where

Xf = the amount of hearing loss at audiometric frequency (in kHz) for the patient.

10 LPf = the lowest click level where wave V is detected in the patient's derived response for frequency region f.

LNf = the lowest click level where wave V is detected in normal hearing subjects' derived responses for frequency region f.

For example, if for the derived responses from the 4 kHz region (f=4) in a patient, wave V can last be detected at a click level of 40 dB HL (i.e. LP4=40 dB) and from the data of normal hearing subjects the lowest level is 10 dB (i.e. LN4-10 dB), then the hearing loss at 4 kHz is X4=40 dB - 10 dB = 30 dB loss.

This technique estimates the hearing impairment at specific frequencies quite accurately in all types of hearing loss. There are two disadvantages to the technique, the time required to complete the test, and the sophisticated, expensive equipment necessary. To perform this analysis expeditiously, a computer system with storage capability is necessary. Even then testing of one ear requires approximately 1.5 hours. To complete the analysis without the capability of data storage would require at least twice as long. Nevertheless, this is a small price to pay for a technique which can accurately assess hearing function in the very young or otherwise difficult-to-test patient.

Use of a Combination of Techniques

Davis and Hirsh have proposed that a combination of techniques be used to approximate the pure tone audiogram. They use auditory brain stem responses to 2 and 4 kHz tone pips to estimate the audiogram at those frequencies. The later SN-10 response to 1 and 0.5 kHz tone pips is used to estimate the hearing at those frequencies. Moushegian et al have proposed that the auditory brain stem responses be used to assess the more basal portions of the cochlea and the frequency following response, the apical region.

Current Status of Threshold Testing

At the prewsent time, we are using broad-band click stimulation to elicit the brain stem responses. From this we estimate the hearing in the 3-4 kHz region of the cochlea. We estimate the low-frequency hearing with the use of impedance audiometry. The presence of an acoustic reflex to a low-frequency stimulus indicates preservation of hearing in the lower frequencies. This finding with an absent auditory brain stem response to high-frequency click stimulation would indicate a sloping type high-frequency hearing loss and would be an indication for caution in fitting of a hearing aid. In such a case we might well prescribe a low-gain hearing aid with high-frequency emphasis.

On the other hand, the absence of an acoustic reflex to a low-frequency stimulus combined with an absent brain stem response to a high-intensity click implies a profound hearing impairment and indicates the need for a high-gain hearing aid.

The use of the frequency-following response, the SN-10 response, and the high-pass masking technique, require further study and clinical verification. Some combination of these techniques give promise of accurate prediction of the pure tone audiogram with objective measuring techniques.

11 Acoustic Neurinoma Diagnosis

Auditory brain stem response audiometry has proved to be the best audiometric test for acoustic tumor detection. The success of ABR depends upon the fact that acoustic tumors stretch or compress the auditory nerve, producing a delay in the response latency which ABR can detect. This delay may occur in an ear with normal hearing. Conversely, cochlear lesions have little effect on the brain stem response latencies for high-intensity stimuli until the hearing loss becomes rather severe.

There are several techniques in which the latency of wave V is used for detection of a retrocochlear lesion. The first is to measure the absolute latency of the wave and compare it to normals. The normal latency for wave V is between 5-5.7 msec. Because of this rather large variability among normal patients, we have not found the measure of the absolute latency of wave V to be very useful in acoustic neurinoma diagnosis.

Another approach has been to measure the interval between the first and fifth waves. This so-called measure of central conduction time has the advantage of removing the error which occurs when there is a high-frequency sensorineural hearing impairment producing a cochlear delay, as described below. Prolongation of the wave I-V interval should reflect only the delay of propagation of the nerve impulse along the auditory nerve secondary to tumor compression.

The difficulty with the use of this technique is that patients with either sensory hearing loss or an acoustic tumor often do not have a recordable wave I. Thus, this technique cannot be used. Coates has increased his ability to use this method by doing simultaneous recordings with an ear canal electrode and scalp electrodes. The ear canal electrode more frequently detects the first wave, while the surface electrodes are used to record the fifth wave. This procedure, however, requires the placement of an ear canal electrode and also necessitates equipment which is capable of simultaneous recording.

Another difficulty in using central conduction time as the only measure of a retrocochlear lesion is that a tumor may cause delay in wave I; wave I-V latency would be normal with all of the waves delayed.

The technique which we use for acoustic tumor detection is to compare the patient's nonsuspect ear with the ear with the suspected acoustic tumor. With this technique, the patient acts as his own control to reduce the variability seen between normal patients.

Interaural Latency Differences in Patients with Normal Hearing

Brain stem responses to an 83 dB HL broad-band click are recorded. The nontest ear is masked by 78 dB white noise. The responses are studied for the detection and latency of wave V which is the largest and most recordable of the peaks. The latency between the two ears (IT5) is compared. In studying a group of normal patients, we found no more than a 0.2 msec difference between the wave V latencies for the two ears.

12 Interaural Latency Differences in Patients with Unilateral Hearing Loss

Nontumor Cases

Patients with hearing impairment greater than 75 dB at either 2 or 4 kHz are excluded because they do not give reliable brain stem responses. When the hearing loss is less than 55 dB at 4 kHz, there is an insignificant effect on the wave V latency. As the hearing loss at 4 kHz increases above 50 dB, wave V latency gradually increases at the rate of about 0.1 msec/10 dB, and it is necessary to introduce a correction factor to decrease the number of false-positive responses.

The correction factor was determined which would eliminate the majority of the false- positive responses without creating any false-negatives (tumor missed), which is a much more serious error. A correction factor of 0.1 msec is subtracted for 4 kHz pure tone hearing loss of 55 or 60 dB, and 0.2 msec is subtracted for hearing loss of 65 or 70 dB. The data are recorded as illustrated in Fig. 3-6.

Tumor Cases

One-half of the patients with acoustic neurinomas have no detectable wave V regardless of the degree of hearing impairment. We consider this indicative of an acoustic neurinoma.

Ninety-six percent of 150 tumor patients have shown an adjusted interaural difference (IT5) of greater than 0.2 msec. Comparing ABR with the other standard neuro-otologic tests, we find that ABR is the most accurate of these tests and also has the lowest false-positive rate (Tabel 3-3). Brain stem audiometry has, therefore, become an important part of our evaluation of acoustic tumor suspects.

Prediction of Tumor Size

Large acoustic tumors press against the brain stem. If significant pressure is exerted on the auditory tracts in the brain stem, abnormalities in the brain stem response are detectable when testing the opposite (nontumor) ear. This effect is best detected by measuring the interval between the third and fifth waves. Normally, this interval, T3-5, will be 1.9 ± 0.1 msec. A T5-3 of 2.1-2.8 msec has been found in 71% of 55 patients having tumors larger than 3 cm. Thus brain stem audiometry may not only predict the presence of an acoustic tumor, but also the general size of the tumor.

Conductive Hearing Losses

One word of caution is in order. Conductive hearing impairments will produce latency shifts that mimic an acoustic tumor. Standard audiometric tests to rule out conductive losses should first be performed.

13 Current Use of ABR in the Neuro-Otologic Evaluation

Our routine evaluation of a tumor suspect includes petrous pyramid x-rays, electronystagmography, and an acoustic reflex test. If the x-rays show definite enlargement of the internal auditory canal on the suspect side, a constrast study is obtained, usually computerized tomography with air contrast if necessary, followed by a small-dose polytome Pantopaque study if the diagnosis remains in doubt after computerized tomography.

If the findings on x-ray are not definite, but the ENG or acoustic reflex test suggests a tumor, we obtain ABR. If that is positive, the contrast studies as described above are performed.

Table 3-3. Four Screening Tests' Failures Listed as Percentages of Tests Performed

ABR X-ray ENG ART

Percent false-negative 4 11 23 30 (tumor missed)

Percent false-positive 8 27 28 28 (false alarm).

Recently we have used ABR as a primary screening test more often. In some cases the ENG and acoustic reflex test have been omitted because of ABR. The ABR is a significant addition to the acoustic tumor detection test battery which is being used with increasing frequency.

Nonacoustic Cerebellopontine Angle Tumors

Twenty-eight patients with cerebellopontine angle tumors, not acoustic tumors, have been studied with brain stem audiometry. Brain stem audiometry has identified the tumor in cases where there has been pressure on the cochlear nerve. Because some nonacoustic lesions of the angle do not produce pressure on the cochlear nerve, the detection rate for non- acoustics is not as good as for acoustic neurinomas (Table 3-4).

Table 3-4. Detection Rate for Nonacoustic Cerebellopontine Angle Tumors (#28)

Wave V - Absent or delayed 75% Wave V - Normal 25% - 3 of 10 meningiomas - 1 of 5 cholesteatomas - 2 of 4 facial nerve neurinomas - arachnoid cyst.

Brain Stem Lesions

Brain stem audiometry is of distinct value in the diagnosis and localization of brain stem lesions. Intra-axial pontine masses which impinge upon the auditory tracts produce loss

14 of brain stem responses. The level of the mass can be predicted on the basis of the presence or absence of succeeding brain stem responses.

Absence of brain stem responses is an early indication of multiple sclerosis in a large percentage of those patients. Lesions in the auditory tract produce desynchronization of the responses which make them nondetectable despite the presence of normal pure tone and speech audiometry in many cases.

Cortical Electric Response Audiometry

At the present time we are not using the cortical responses in our clinical practice. Nevertheless, a brief review of possible clinical application of these potentials is presented.

Slow and Late Potentials

Initially, the vertex potentials were explored for threshold testing. Some reasons for recording these potentials are: (1) they represent activity of higher central levels and, therefore, are apt to reflect more of the "hearing process", (2) stimuli more frequency specific than clicks (i.e. tone bursts) can be used to elicit a response, (3) the responses are relatively large and require only a small number of trials.

However, after a few years of research and application, it was evident that vertex potentials do not result in accurate threshold testing. They seem to correlate well with the audiogram (within 10 dB of threshold) in waking adults, but they are affected by the patient's physiologic state and by medications and anesthesia. More importantly, these responses are not reliable in children, the population most in need of an ERA technique. In general, the slow and late cortical potentials may be reliable in waking adults; in children these responses are unreliable either because they vary or, as with "expectation waves", they require some behavioral interaction. Thus, these responses can occasionally be used for gross testing but must be interpreted with great caution.

Middle Components

After the slow and late cortical responses lost their appeal, electric responses in the 12-50 msec range began to be examined. Unlike the slow and late cortical potentials, middle components remain stable whatever the subject's state - alert, asleep, even lightly sedated. However, they are affected by anesthetic levels of sedation. With use of filtered clicks or tone pips, middle components are better for predicting thresholds of various frequencies than the slow cortical potentials.

One major disadvantage of responses in this middle time domain is contamination by the myogenic responses. For threshold testing, whether the response is myogenic or neurogenic may be irrelevant as long as both responses are mediated by the auditory pathway. However, at high-stimulus levels, some of these myogenic responses from the scalp muscles are thought to be mediated by other portions of the labyrinth. The claims are that the middle responses will yield threshold estimates within 10 dB of the behavioral threshold in the waking state and about 20 dB in the sleeping state. This suggests that sleep has an effect on thresholds. Moreover, the amplitudes are smaller in infants and yield thresholds of about 30

15 dB normal hearing level (nHL). It is difficult to determine when middle responses should be the ERA method of choice, as many of their advantages over slow and cortical responses are the same advantages of brain stem and ECoG methods. It also should be noted that some researchers have had difficulty recording and using the middle components in children, while others have apparently had success. Perhaps middle responses can be used to provide information on some level (primary cortex?) of processing and thereby aid in assessing central problems.

Because of the difficulties in recording these later responses, the earlier surface- recorded brain stem responses are of much greater clinical usefulness.

Conclusions

Electric response audiometry is an exciting new development with broad implications in the fields of otology, audiology, and neurology. At the present time it is the best objective audiometric test for predicting hearing thresholds in infants or uncooperative patients.

Electrocochleography offers a means for study of the function of the inner ear and for differentiation of types of sensorineural hearing impairment. Auditory brain stem response audiometry is a valuable addition to the audiologic test battery for acoustic tumor diagnosis. It also offers a means of studying brain stem function in a variety of neurologic disorders.

16 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 4: The Vestibular System and its Disorders: Part I

Physiology of Vestibular System

The physiology of the vestibular system is the applied anatomy of three semicircular canals; the lateral where there is no medial, the superior where there is no inferior, and the posteriro where there is no anterior. These are at approximate right angles to each other. In addition there are two otolithic organs, the utricle and saccule.

The fundamental microscopic anatomy of hair cells of the inner ear is the same. Each hair cell has hairs or cilia of two varieties. There are stereocilia which are arranged in an ascending, pipe organ structure, and one kinocilium located at the end of the tallest stereocilia. The kinocilium is less rigid in structure and appears wavy and more flexible. It is the deflection of the cilia either toward or away from the kinocilium that stimulates the hair cell. Each hair cell has a resting electic discharge, i.e. a discharge of measurable electric activity without stimulation or deflection of the cilia. If the cilia are deflected toward the kinocilia, the rate of discharge is increased, while deflection away from the kinocilia will decrease and possibly abolish the discharge depending upon the intensity of the stimulus.

The hairs of the hair cells are inserted into a gelatinous layer which is reponsible for the manner in which the hair cells are deflected. In the semicircular canal this mass is called the cupula and extends across the endolymphatic fluid space of the ampulla to insert into the endosteal membrane. Therefore, as the endolymph flows in response to angular acceleration, i.e. rotational or caloric stimuli, rather than flowing over the cupula like a swinging door, the cupula deflects it like a sail. This endolymph flow then stimulates the semicircular ducts.

The otolithic system has, in addition to its gelatinous membrane, a mass of calcium carbonate crystals (rock pile) which renders that membrane sensitive to the effects of gravity and head tilt. The utricle is the primary otolithic structure sensitive to linear acceleration. The function of the saccule is not clear at this time. It may function similar to the utriculus and/or may function as a low-frequency sound or vibration sensor.

Since the hair cells have "polarity", i.e. where the kinocilium is located, they are lined up in functional groups. In the lateral semicircular canals the hair cells of the ampulla are all found with the kinocillia closest to the utricle. In the superior and posterior semicircular canals the kinocilia are located away from the utricle or on the crus commune side of the ampulla.

In the otolithic membranes, the hair cells are lined up with the kinocilia facing a line which almost bisects the membrane. This line is named the striola. This latter formation allows for the sensitivity seen in head tilt.

Let us examine the right lateral semicircular canal (SCC) by caloric stimulation which permits only one SCC to be stimulated. A caloric stimulus with a temperature cooler than body temperature, with the lateral SCC placed vertically causes a flow of endolymph in an ampullofugal (away from the ampulla) or utriculofugal (away from the utricle) direction. This

1 causes a deflection of the cilia of the hair cells of the lateral SCC away from the kinocilia. The result is a decrease or abolition of the electric discharge output of the hair cells of the lateral SCC, which in turn results in a reduction of the electric potential of the ipsilateral vestibular nuclear cells responding to hair cell stimulation. In addition, vestibular nuclear cells sampled on the contralateral side of the brain stem will show a corresponding increase in electric potential. When this potential difference occurs accross the brain stem, the medial longitudinal fasciculus (MLF) is stimulated which provides stimuli to the oculomotor nuclei, particularly III and VI, for lateral SCC stimulation.

Similar to the resting discharge of the hair cells, the extraocular muscles of the eyes have a constant group of muscle fibers contracting, and may increase or decrease the muscle mass contracting to move the eye. Thus with increased potential on the left side of the stem there is relaxation of the medial rectus of the right eye and the lateral rectus of the left eye and a corresponding increase in contraction of the lateral rectus of the right eye and medial rectus of the left eye. This results in a slow eye movement to the right. When the eyes reach a critical deviation to the side, a feedback input probably through the oculomotor system to the prepontine reticular formation evokes the rapid corrective quick component of nystagmus. By convention nystagmus is named by its quick component.

Similarly, if the other ear was stimulated with water cooler than body temperature, the nystagmus produced would be the opposite of the first ear. If the right ear was stimulated with water warmer than body temperature, then this would result in an ampullopetal (towards the ampulla) or utriculopetal (towards the utricle) movement, which results in a deflection of the cilia towards the kinocilia. This increases the discharge of the hair cell population of the lateral SCC over the resting potential. In the brain stem there is an increase in the potential of the ipsilateral vestibular nuclear cells receiving input from the SCC and a corresponding decrease in the potential of the contralateral vestibular nuclei. This reproduces the events of the brain stem similar to a cool water stimulus in the left ear. Thus the right beating nystagmus produced by cool water in the left ear will be the same nystagmus as produced by warm water in the right ear.

If water of the same temperature was irrigated into both ears, and if the response in both sets of hair cells was equal, the resultant effect in the brain stem vestibular nuclei would be no change, therefore no stimulation of the MLF and no nystagmus produced.

Similarly, a lesion in the inner ear, vestibular nerve, vestibular nucleus, or internuncial nerve tracts of the vestibular nuclei can produce a differential across the brain stem resulting in a spontaneous nystagmus. If the differential were not present except under stimulus conditions then this may be evident by a reduction in caloric response, or nystagmus on the changing of the head position.

Thus the effects of caloric stimulation can be understood as well as the rotary stimulation of the lateral SCCs. The posterior and superior SCC also can be stimulated but produce an oculomotor response which at present is difficult to sort out for clinical diagnostic purposes.

2 The otolithic system produces ocular counterrolling which allows for some measure of function. This technique is cumbersome, difficult, and can be fraught with interference by other oculomotor phenomena.

Methods of Testing the Vestibular System

At this time any test of the vestibular system without an electrical recording of nystagmus behind closed eyes may mislead the clinician in the proper management of the patient. Electronystagmography (ENG) is an electronic method of producing a permanent record of eye movement. This movement can occur with or without the eyes open, in any position of the head, and under any circumstance of stimulation of the vestibular system. A method of vestibular evaluation is described along with the derived conclusions of the test.

The patient is ushered into a room that is permanently set up as a clinical vestibular laboratory. The technician or physician explains all aspects of the procedure as it progresses, both to relieve apprehension and to act as a form of constant alerting for the patient. The patient is seated on the ENG table and the ears are examined for obstructive cerumen, tympanic membrane perforations, or the presence of mastoid cavities. After that, the patient lies supine on the table and the skin is cleansed and dried where the electrodes are to be placed. The electrodes are applied to the skin after filling the electrode cup with a coupling electrode jelly or paste. The ground electrode is placed above the bridge of the nose. The electrodes for recording horizontal nystagmus are placed on the skin as close as possible to the outer canthus of both eyes. The electrodes for recording vertical nystagmus are placed above and below one eye. If necessary, and if the recorder has the capability, each eye motion can be separately recorded with an array of electrodes around the eye. Once the electrodes are applied, the gain of the recorder is adjusted to produce a specific deflection of the pen on the paper in keeping with the magnitude of a calibraing eye movement. This is accomplished by following alternating lights a known distance apart. Once calibrated, the eye movement can be recorded behind closed eyes. The electric potential change being recorded emanates from a potential between the cornea and retina moving within the recording field.

Once calibrated, the corneoretinal potential may vary with the amount of light stimulation of the eyes. It may be necessary to alter the gain from time to time during the testing time in a recalibration procedure.

The patient can then be placed in various positions to see if nystagmus can be recorded. The nystagmus may occur in only the supine position, the right lateral, the left lateral, or all of the position. It may be beating all in the same direction, or the direction of beating may change in one or more positions.

The velocity of the nystagmus may change significantly from one position to the other. Turning the head (neck torsion) also may produce nystagmus, turn off the nystagmus, or enhance any nystagmus already present by just lying on that side. The presence of nystagmus in any of the foregoing is abnormal. The significance, however, is not clear. Some form of spontaneous positional, or positioning nystagmus may be present and is abnormal. It may not represent a serious problem, or it may be the only clue to substantiating an organic vestibular disorder and uncovering a potentially serious health problem, such as an acoustic tumor.

3 The caloric tests have been recognized as the most beneficial in vestibular diagnosis. Each ear can be stimulated separately. By using a bithermal stimulus (30°C and 40°C) the same ear can be stimulated and produce an opposite direction of beating of nystagmus. Thus with the patient's head elevated 30°C from the supine position, the lateral SCC is positioned in the vertical plane, and the maximum effects of stimulation of the endolymph can occur. A unilateral weakness of an ear is recognized when there is less nystagmus produced with both the warm and cool stimulation of one ear compared with the other ear. At times the response is not clear and a mathematical formula comparing the difference in velocity of response from one ear to the other, expressed as a percentage of the total response, may shed light on the quantity of difference. Thirty percent was derived in some studies while others use a 25 or 20% difference to recognize a reduced vestibular response (RVR).

At times there is more nystagmus produced in one direction than the other even though the difference between ears calculates as normal. The tendency to have a significantly greater amount of right-beating nystagmus, for example, is named a "directional preponderance" (DP). Where it is not obvious, a formula also may be used expressing the difference in right-beating nystagmus from left-beating nystagmus as a percentage of the total response of all four bithermal stimuli. Some investigators use from a 30% down to a 15% difference as a significance level. When present, and pathologic or significant, it means that the system is not functioning normally, but it has no localizing value as to right or left, central or peripheral.

Clinical Presentation

History

1. With problems of dysequilibrium, the ability to give clearcut historical information is dependent upon the patient's vocabulary and previous experience of vestibular stimulation. Some may express being "just dizzy"; others may feel a rotary experience. With others there is an illusion of movement of the environment without rotation. Unsteadiness, light- headedness, walking on a cloud, or a floating feeling are other expressions of symptoms which are often referable to abnormalities in the vestibular system.

2. Hearing loss, tinnitus or fullness of the ear(s) will often lead to an otologic origin.

3. Difficulty with speaking or swallowing while walking, otherwise exercising, or expanding cardiac output may be a sign of vascular insufficiency.

4. The character of the dysequilibrium such as onset, duration, frequency, disability, precipitating circumstances, aggravating circumstances, and those which improve the symptoms may provide clues to the cause.

5. The family history may provide information about neurofibromatosis, diabetes, otospongiosis, or other factors.

6. Surgical or accidental trauma, as well as the use of drugs for extended periods, also may provide etiologic clues. Associated medical illnesses should be catologued according to factors in the symptoms.

4 Examination

1. The ears are examined for evidence of trauma to the tympanic membrane, serous otitis media, or evidence of chronic otitis media. The sensation of the posterosuperior aspect of the skin of the medial portion of the external canal may be examined for sensitivity.

2. The use of tuning forks will give clues to conductive or unilateral sensorineural hearing loss. The response of the ears to the forks may outline the anticipated audiometric findings.

3. Next, the remainder of the cranial nerves are examined. The olfactory nerve is difficult to fully examine, but the third, fourth, and sixth are easily examined in searching for gaze nystagmus or any other eyes-open nystagmus. Cranial nerve II is judged by confrontation. The fifth cranial nerv, so important in acoustic tumor diagnosis, can be assessed easily in three areas: corenal sensitivity, light touch, and pinprick in all three divisions. The facial nerve may not display evidence of paralysis but a difference in the width of the orbital fissures or a flattening of the nasolabial fold may provide subtle findings of its early compromise. Nerves IX, X, XI, and XII all become part of the remainder of the head and neck examination.

Audiology

1. Pure tone (air or bone), along with speech reception and discrimination, provide the bare bones and minimum of the auditory function evaluation.

2. Impedance testing including tympanometry and stapedial reflexes, both ipsilateral and contralateral are also essential. In addition, where the stapedial reflexes are present, decay also should be sought.

3. Auditory brain stem evoked potentials will add further knowledge toward understanding the neurophysiology and neuropathology of the hearing mechanism.

4. There are a host of other tests such as SISI, Bekesy's, ABLB, difference limen testing, etc, which have been by and large supplanted by the more modern previously described tests.

Electronystagmography (ENG)

1. The first part of the test occurs with calibration. Consistent overshoots, if present on calibration of horizontal eye movements with small enough calibrating lights, are a sign of ocular dysmetria. This should be considered a sign of a central lesion.

2. Once calibrated, a search is made for nystagmus with the eyes closed in the supine and left and right lateral positions. A portion of the tracing will also include eyes open to see the effect of ocular fixation. This also tends to reduce the intensity of corneoretinal potential change with prolonged darkness. Nystagmus, when found in these positions, is abnormal and this is the most important contribution. When it occurs only once with one ear down, this may provide an additional clue along with the history, clinical examination, audiology, and caloric

5 response to the origin of the dysequilibrium. At times nystagmus will be found in all position. When it is the same direction and similar velocity, then this can be named spontaneous nystagmus. Spontaneous nystagmus is abnormal when present. It has no localizing value as to the site (central or peripheral) or the side (right or left) no matter which direction the nystagmus.

When the nystagmus is the same direction in all positions but varies in velocity, it is a direction-fixed nystagmus. The majority of such findings are peripheral, but not always. At times when there is a large difference with one ear down compared with the remainder of the positions, the difference then may have diagnostic value. The ear down is not always an indication of the pathologic site. This must be correlated with other findings before arriving at a conclusion. To arrive at a decision based upon the position response alone will be erroneous in a small but significant number of patients.

When the nystagmus is present in all positions but changes in direction, it is named a direction-changing positional nystagmus. While this is thought to be a central sign, it is sufficiently inaccurate to be relied upon as a central sign. Of importance is the right-beating nystagmus with the left ear down only, and the left-beating nystagmus with the right ear down only. This is suggestive of the second phase of positional alcohol diffusion, becoming gravity dependent and representing a peripheral abnormality of ingested alcohol over the prior 24-48 hours. Careful questioning is important as to ingestion of substances which could alter the vestibular evaluation.

3. While the lateral positions give evidence mainly about the effect of the otoliths, the addition of turning the neck into these positions adds input from the cervical nerves. These can either produce a nystagmus not previously present, enhance or reduce a previously existent nystagmus, or turn off or produce a nystagmus in the opposite direction. This effect is very potent and must be considered in the development of the symptom complex. The possible effect upon the vertebral arteries also should be considered. The latter tend to play a lesser role in the production of symptoms as a whole.

Alternate Binaural Bithermal Calorics

The caloric stimulus provides the most information about the functioning of the vestibular system. Two temperatures of water, one above and one below body temperature, must be used. Since the response produced will be nystagmus in one direction with one temperature and the other direction with the other temperature, two facets can be examined. Both the warm and cool responses may be reduced in one ear compared with the other. In some instances the use of Jongkees' formula may provide a numerical percentage difference not readily apparent from "eyeballing" the nystagmus. Where there is a directional preponderance than the cool in one ear and the warm in the opposite produces a nystagmus response in which the intensity is greater than the opposite-beating nystagmus. This points out fallacy of using a screening warm or screening cool stimulus. If one were to examine a single screening technique, then 60% of the time the warm hypoactive response would point to the lesion. This leaves an accuracy of about 40% if the cool stimulus were used as a screening temperature. Some laboratories, if the cool responses were low enough, would add an ice water stimulus to determine if more function could be found.

6 Simultaneous Binaural Bithermal

By stimulating both ears simultaneously with the same temperature of water (i.e. 30°C) and looking for nystagmus followed, after an appropriate rest period, by a simultaneous stimulation of the other temperature of water (i.e. 44°C), a more sensitive stimulus was found. The nystagmus responses are divided into four groups, or types, on the basis of the presence of nystagmus and its direction. By stimulating both ears simultaneously, the brain stem receives equal and opposite stimuli. The vestibular nuclear cells perform the task of processing the input. If it is entirely equal and opposite, then no stimulation of the MLF occurs. If the response in the brain stem results in a difference, then the MLF is stimulated. As such, the results of the stimulus produce diagnostic information 55% more sensitive than the alternate binaural bithermal method alone. However, if the simultaneous stimulus were used alone, then an error of at least 2.5% would be made. So, the simultaneous binaural bithermal stimulus is recommended as a 6.5 minute addition to the alternate stimulus in the course of vestibular evaluation.

Massive Caloric

Some patients who have had previous attempts at labyrinthectomy, or with apparent absent function on bithermal testing, may require further testing. If the dizziness persists and is disabling, a more thorough labyrinthectomy or vestibular nerve section may be considered. A search is made for any residual function to be destroyed. A massive caloric stimulus may demonstrate this function. Two temperatures of water are used; ice water and 46-48°C. If there is a preexisting nystagmus, the the first temperature of water delivered to the ear in question should increase the velocity of the preexisting nystagmus. This is followed immediately with the other stimulus. The recorder remains on during the entire stimulus time. The volume delivered is about 300 mL in about 30 seconds for each stimulus. A search is made for the production of and reversal of nystagmus as a demonstration of residual caloric function. As a footnote, the integrity of only the lateral SCC is examined and if the massive test fails to stimulate any residual function, any further decision making will require information from other areas.

Dysrhythmia

There are two types: alerting and central. The alerting type is normal and occurs with a bored or poorly alerted patient. The recording shows bursts of clear, regular, sawtooth nystagmus interrupted by intervals of no nystagmus at the point in the response where the nystagmus should be brisk. This can be alleviated by changing the alerting task or making it more difficult.

Central dysrhythmia is recognized by nystagmus beats whose amplitude, velocity, and morphology bear no resemblance to each other. That is, the central regulatory mechanism is unable to produce even and regular nystagmus beats.

7 Ocular Fixation Suppression

When the nystagmus produced is at its most brisk, then opening the eyes should reduce or eliminate the nystagmus by mere ocular fixation or the attempt at fixation. This finding occurs with a normal vestibular system or in one with a peripheral vestibular disorder. In some central lesions the caloric-induced nystagmus will not appear until the eyes are opened, will significantly increase when the eyes are opened, or will show no signs of suppression of the already present, induced nystagmus. The test should be performed on all four caloric responses to the alternate binaural bithermal stimulus. When present this is a reliable sign of a central disorder.

Future Tests

With the explosion of the computer field and electronic and mechanical technology, newer tests of the vestibular system will become available. At this time (1981) the use of rotation chairs with a computer appears to provide additional helpful clinical information. While both ears are simultaneously stimulated, the information on the laterality of a lesion cannot be accurately deduced. However, by looking at the gain of the vestibulo-ocular reflex with differing frequencies of rotary stimulation, the responses can be classified into normal, central, or peripheral in fairly clear-cut categories. By looking to the degree of labyrinthine preponderance, the degree of compensation of a vestibular lesion then can be assessed. In many instances a patient may demonstrate a stable abnormality in the ENG and yet be fully compensated and symptom free, or fully symptomatic and disabled. The abnormality on the ENG may be exactly the same. The degree of labyrinthine preponderance has shown evidence of compensation when it is present.

Tracking tests using a pendulum or optokinetic stimulus have demonstrated little or no usefulness in clinical testing. The use of a computer generated, LED screen stimulus and a computer analyzed response may provide more accurate clinical data. Unfortunately, as with all-eyes-open voluntary tracking tests, patient cooperation significantly factors into the validity of the test results.

Clinical Entities

Metabolic Vertigo

There are no clinical symptoms which separate metabolic vertigo from other forms. A prerequisite may be an abnormally functioning vestibular system. In this instance the metabolic factor exaggerates of interferes with the compensatory mechanisms and brings about the symptoms. It is imperative to include metabolic studies. These may indicate a contribution to the symptoms that when eliminated may improve the symptoms to a livable rather than disabling level. Elevated blood fats or a fluctuating blood sugar commonly can be found where there is a diet too high in carbohydrates and/or animal fats. Dietary modification often will result in a striking improvement in symptoms.

Hypothyroidism is an extremely rare but definite cause. Many times the patients are not otherwise clinically hypothyroid. The inclusion of a test for hypothyroidism probably is justified.

8 Lastly, allergic causalities are very elusive in the management of a dizzy patient. A screeing IgE may give a clue; RAST or skin testing may provide more precise findings about an allergic cause and its treatment. In the absence of a clear-cut history, the allergy evaluation is indicated in the absence of any other clearly defined cause.

Perilymph Fistula

This finding as a cause for vertigo in the absence of hearing loss is found more frequently than expected. The history should be straightforward for trauma or air travel and the resultant symptoms clearly follow. Such is not always the case since a sneeze or vigorous blowing of the nose may be the inciting event. The resultant vertigo may not occur for some period.

The clue in the history is one of an episodic nature usually related to exertion. Many patients will be asymptomatic on awakening in the morning only to have symptoms appear once they are up and around. A positive fistula sign with or without ENG is helpful, although a negative sign does not rule out a fistula.

Associated symptoms of ear fullness, tinnitus, and mild or fluctuating hearing loss will help to localize the ear. In addition, the caloric findings, especially the simultaneous calorics, are most helpful. Many patients will demonstrate nystagmus with the affected ear down. However, this alone is not a reliable sign to localize the pathologic ear.

Ménière's Disease

The histopathologic temporal bone finding correlated with this disease is endolymphatic hydrops. In its pure form the hydrops should have no traceable cause such as suppuration, trauma, otospongiosis, and syphilis.

The symptoms, where complete and classically present, include fluctuating sensorineural hearing loss, fluctuating tinnitus, and fluctuating fullness in the affected ear. In addition, as the tinnitus, fullness, and hearing loss intensify an attack of vertigo will follow. These tend to occur in episodes. The process may spontaneously remit never to occur again and leave no residual or perhaps a mild hearing loss and tinnitus. It also may go on with recurring disabling vertigo and progressive hearing loss.

The idiopathic form is not commonly bilateral. If bilateral, a causality needs to be conscientiously ruled out.

The symptoms also may occur alone as in cochlear Ménière's disease; vestibular Ménière's disease, or Lermoyez's syndrome. In general, these will have ear fullness as the common denominator.

The audiology findings, where present, will show an early fluctuating low-tone sensorineural hearing loss. The discrimination initially is well preserved. Site-of-lesion tests will demonstrate a cochlear lesion. With serial hearing tests and no remission, the hearing loss will fluctuate with changes in the pure tones, or in the speech discrimination scores or both. Eventually the hearing levels will decline, with mainly evidence of fluctuating discrimination

9 scores. Untreated, the discrimination scores eventually will yield no useful hearing ability even with amplification.

The ENG findings commonly show very little between the initial episodes. During the attack there may be active spontaneous nystagmus with direction changing components even in the midst of caloric testing. Alternate bithermal calorics may reveal an abnormality about 50% of the time, while simultaneous bithermal calorics will increase the yield to 80%.

The natural history is of a final and complete remission in about 60% of the patients. The end point in the hearing loss and vestibular disorder varies with the point of the remission. Residual tinnitus also may be a disturbing factor.

Since the stage at which a spontaneous remission will occur cannot be predicted, several medical and surgical therapies have evolved to alter the end results. Each therapy has its strong advocates. The presentation of the disease with its long remissions and exacerbations, and the inability to measure the degree of hearing loss or vestibular disturbance on line, make it an enigma for therapy.

The medical therapies are aimed at the symptoms and include vestibular suppressants, vasodilators, and diuretics.

The surgical therapies are either destructive, conservative, or preservative. The first includes labyrinthectomy or translabyrinthine eight nerve section where there is no useful hearing. Selective destructive procedures where there is useful hearing include midfossa vestibular nerve section, ultrasonic irradiation of the labyrinth, or cryosurgery.

Conservative procedures include those performed on the endolymphatic sac. These range from sac decompression to endolymphatic-mastoid shunts to endolymphatic- subarachnoid shunts. The endolymphatic-subarachnoid shunt appears to be directed at a correction of the resultant mechanical changes seen in the histopathology of the hydrops.

The tack procedure appears to result in a steady decline in the hearing, while there has been little experience with cochleostomy as a treatment.

As statistical methods and means of evaluation improve, the results of the various therapies will be clarified and the total management of this enigma standardized.

Acoustic Neurinoma

This benign tumor has its origin most commonly in the superior vestibular division of the eight cranial nerve. Because these are slow growing, very few symptoms arise as this division of the eight nerve is being compromised. Compensation for the slow loss of the nerve results in no marked vestibular complaints. As the enlarging tumor spills over into the cochlear division of the eight nerve or compromises the artery to the inner ear, hearing symptoms will manifest themselves. This will produce either unilateral tinnitus or hearing loss or both. Occasionally the findings may be indistinguishable from a hydrops. With time there is a progressive hearing loss with discrimination affected long before a total hearing loss occurs.

10 As the tumor enlarges it compresses the surrounding nerves. The seventh (facial) nerve, primarily a motor nerve, seems to be resistant to the pressure effects of an enlarging tumor. Even though this is the nerve next affected, visible signs of facial nerve palsy are very late. More commonly, the effect of pressure on the fifth (trigeminal) nerve is demonstrated by altered corneal sensation, the first modality of this nerve that is usually affected. Later there may be symptoms of numbness in any or all divisions of the nerve.

The next area affected varies with the size and direction of tumor growth. If the growth is more medial, the obstruction of flow of the cerebrospinal fluid may result in hydrocephalus; if more posterior, then cerebellar signs may be elicited. An inferior growing tumor may give rise to findings in cranial nerves IX, X, XI, and XII. At the extreme of the very large tumor there may be signs of the effect on all of the above nerves.

These tumors also may arise from the cochlear nerve where symptoms will appear clearly, or the inferior vestibular nerve where the findings are characteristically very late.

The early diagnosis of these tumors requires a high index of suspicion and diligence in the diagnostic pursuit. When the tumors are quite large they represent no diagnostic dilemma.

The audiologic evaluation may vary from normal hearing in a normal pure tone audiogram with poor speech discimination, to a pure tone sensorineural hearing loss and poor or no speech discrimination. A search for stapedial reflexes with the impedance bridge may show reflexes present at normal levels without evidence of decay in about 18% of the tumors. The reflexes are helpful when absent or show evidence of decay of the reflex when the behavioral pure tones are in the normal range.

Auditory brain stem evoked potentials also may increase the index of suspicion. This test although very valuable is known to have its false-positive results, but more importantly, its false-negative.

The vestibular evaluation heightens one's suspicions when there is an absent caloric response in the suspect ear in the absence of any history of dysequilibrium. Alternate binaural bithermal testing observes the function of the superior vestibular nerve while the simultaneous stimulus uncovers more abnormalities consistent with the tumor.

The radiologic evaluation provides more reason for suspicion and finally the indication for surgery. Plain roentgenograms and more accurately complex motion tomography of the temporal bone may show an enlarged internal auditory canal. While a 1.5-2.0 mm difference is accepted as the radiologic normal variation, if this occurs on the suspect ear, the coincidence is too great to overlook. Large differences also may be present.

With the suspicion present, CT scanning with intravenous contrast is the first step. This will identify tumors of 1.5-2.0 cm or larger. To identify smaller tumors some contrasting substance needs to be physically introduced into the angle. Currently, air or CO2 with high- resolution CT scanners has outlined smaller tumors or those within the internal auditory canal. False-positive findings have been found as more experience is gained with this modality.

11 Positive contrast iophendylate in the posterior fossa with plain or complex motion tomography also will outline a mass in the canal or angle. This method also uncovers vascular loops and arachnoid cysts which cannot be differentiated from the tumor until the time of surgery.

The surgical treatment has advocates among the neurosurgeons and the neurotologic surgeons. The area of agreement in the surgical treatment demands the use of the operating microscope. The patient in a sitting position, as used by some neurosurgeons, may result in problems of quadriplegia or air emboli. Thus the supine or prone position may be preferred.

When there is hearing worth preserving and the tumor is within the internal auditory canal, the midfossa approach has the best chance for tumor removal and preservation of the hearing. When the hearing is good and the tumor is well into the cerebellopontine angle there are advocates for suboccipital removal. The exact number of patients whose normal hearing has been preserved has not been tabulated. In addition, the mobidity may be increased.

The translabyrinthine approach can be used when there is no useful hearing. Some surgeons will recommend the translabyrinthine approach because they experience less morbidity and find it impossible to preserve hearing when the tumor is out of the internal canal. Others may recommend the suboccipital approach.

Some combine the advantages of the translabyrinthine and suboccipital approaches into a one-stage removal of very large tumors.

Multiple Sclerosis

This neurologic disease with lesions disseminated in space in the neurologic system in time may present with vestibular symptoms.

The lesions may be exaggerated by warming the body temperature. The electronystagmography may show anything from normal findings, to peripheral findings, to central findings. Auditory brain stem-evoked potentials may show delay of central conduction. More likely, there is significant delay of the visually evoked potentials.

Evidence of anterior internuclear ophthalmoplegia on testing eye movements also may give a clue to this neurologic disease.

Syphilis

The otologic findings generally consist of bilateral clinical endolymphatic hydrops. There is significant hearing loss and usually bilateral absent caloric function. The patients as a rule are in the mid-40s. The serologic tests which rely on the presence of reagin are usually negative. The specific treponemal tests such as the fluorescent treponemal antibody absorption or hemagglutination inhibition are positive.

The treatment consists of a course of penillin therapy and desensitization to this drug, if possible, in those patients allergic to penicillin. The use of steroids may result in a dramatic

12 improvement in hearing and reduction of vestibular symptoms. Usually the steroids must be maintained indefinitely to retain the clinical improvement.

Posttraumatic Vertigo

This comprises a history of head trauma followed by a number of possible symptoms. The common denominator is dysequilibrium. If there is a total hearing loss then the use of vestibular suppressants may result in a cure which is sustained after cessation of the suppressants. In some instances where there is no cure, a labyrinthectomy or eighth nerve section will ameliorate the symptoms.

Occasionally there is a progressive hearing loss which therapeutically is managed in the same manner as the immediate hearing loss and vertigo.

Delayed endolymphatic hydrops, which is resistant to medical therapy, may develop. In this instance endolymphatic sac surgery will improve the symptoms, provided there is no fracture displacement through the endolymphatic duct. This latter findings may not be evident on a precise radiologic study or at the time of surgery.

The dislodging of otoconia which roll toward the ampulated end of the posterior semicircular canal has been postulated as a cause for positional vertigo of a posttraumatic type. The nystagmus is said to occur with the affected ear down, and singular nerve neurectomy is recommended as the therapy. While this may occur there are some errors in taking the undermost ear as the pathologic site. In addition, the use of habituation to reduce the symptoms may supplant surgery as the mode of therapy.

Otospongiosis (Otosclerosis)

There appear to be three areas where otospongiosis may bear a relationship to dysequilibrium. The first occurs in relationship to the fixed footplate. By having a fixed footplate, there may be a change in the fluid dynamics of the inner ear giving rise to vestibular symptoms. In a highly reliable number of patients the symptoms are cleared by stapedectomy.

Sometimes vertigo may begin after stapedectomy. This may occur with a perilymph fistula which requires revision and repair. A total, irreversible loss of hearing with vertigo also may occur, and a destructive procedure of labyrinthectomy or eighth nerve section is indicated if the vestibular suppressants fail to control the dysequilibrium.

Endolymphatic hydrops secondary to an otospongiotic process has been described from histologic evaluation of the temporal bone. This must be considered in the etiology of hydrops and may respond to fluoride therapy.

The coexistence of otospongiotic foci around the vestibular labyrinth with elevated blood fats or abnormalities of blood sugar may give rise to vestibular symptoms. The effective treatment here requires fluoride therapy and attention to diet.

13 Vascular Insufficiency

Vascular insufficiency also may give rise to vestibular symptoms. This usually occurs in the elderly patient or those with other evidence of extensive vascular disease. The vestibular findings may show bilateral absent caloric function. Angiography in the absence of focal neurological findings is probably not justified nor likely to lead to a different therapeutic regimen.

The subclavian steal syndrome may be found by differential blood pressure in the arms or direction Doppler confirmed by specific aortic arch angiography and surgical treatment.

In some instances, anticoagulation may be tried as a diagnostic test and continued if therapeutically indicated.

Vestibular Neuronitis

This clinical entity begins with a nonspecific viral illness followed in a variable period of up to 6 weeks by a feeling of dysequilibrium which may be disabling. There are no symptoms or findings in the cochlear system. Electronystagmography demonstrates a unilaterally reduced caloric respone. The remainder of the evaluation is negative for a cause. In most patients, the symptoms, in relation to vestibular compensation, clear with time. This may be hastened by the use of effective vestibular suppression for a period of up to 6 weeks.

A small percentage of patients so afflicted will not respond to vestibular suppression or to vestibular compensation. In these, after an appropriate observation period, a midfossa vestibular nerve section is indicated. Abnormal myelination has been found in some of these nerve specimens.

Otitis Media

Either suppurative or serous otitis media may have vestibular symptoms in association. In serous otitis media the presence of fluid in the middle ear restricting the round window membrane, and/or serous labyrinthitis from diapedesis of protein through the round window membrane, may be responsible for the vestibular symptoms. Removing the serous fluid either medically or surgically gives rise to a remission of the dizziness.

In the presence of suppuration there may be a reversible serous labyrinthitis, or an irreversible suppurative labyrinthitis and the more extensive sequestrum, with a dead ear and facial nerve palsy. In these instances judgment of the disease and its effects will determine the proper treatment.

Ototoxic Drugs

These predominantly aminoglycoside antibiotics are usually used in lifesaving situations where no other antibiotics are judged to be as effective. Vestibular evaluation utilizing ENG will demonstrate no response to warm, cool, or ice-water testing. Minimal response may occur in some instances. The patients may range from being totally incapacitated to being only marginally disabled. The main symptom is oscillopsia, and results

14 from lack of otolithic input to allow the eyes to maintain a level horizon while the head is bobbing up and down as the individual walks. Sometimes the usual vestibular suppressants may aid the patient. In other instances one is frustrated by an inability to adequately treat this condition.

Drugs

A complete drug history is essential as many drugs alone or in combination may act centrally or peripherally to induce symptoms of dysequilibrium.

Alcohol is a common drug whose effect is clearly on the end organ in the second phase of positional alcohol nystagmus. This shows a left-beating nystagmus while lying on the right side and the opposite while lying on the left side. There is no nystagmus in the other positions. This effect can be neutralized by ingestion of heavy water before alcohol ingestion.

Cervical Vertigo

An injury to the neck affecting the spinovestibular input can give rise to dysequilibrium. As more of these patients are studied, another lesion somewhere in the vestibular system also is being found. However, the neck lesion brings out the dysequilibrium and if adequately treated can relieve the symptoms.

Vertigo in Epilepsy

Dysequilibrium as a symptom of epilepsy is seen in two forms. The first is an aura of a major jacksonian seizure. The second is the momentary, almost petit mal, seizure whose entire brief movement is experienced as dysequilibrium. The diagnosis of this latter form may require a sleep EEG. These patients will respond to usual seizure control therapy.

Cardiovascular Causes

Arrhythmias usually may produce dysequilibrium. These rarely presents to the otologist but are seen in consultation with the cardiologist. However, consideration must be given when seeing a new patient with dysequilibrium.

Intracranial Tumors

There is a small but definite number of intracranial tumors which have hitherto gone undiagnosed. These have some degree of dysequilibrium associated with them. The use of CT scanning, without and with intravenous contrast in selected patients, may help to identify these otherwise silent lesions. The type III response to simultaneous binaural bithermal stimulus may be helpful here.

15 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 5: The Vestibular System and its Disorders: Part II

The term dizziness has often been used imprecisely. It is imperative for an otolaryngologist to be able to differentiate the following terms:

Dizziness: Encompasses any discomfort, other than pain, related to the head. The etiology could be visual, cerebral, vestibular, or gastrointestinal.

Vertigo: Describes a discomfort in a patient experiencing an actual sensation of motion in which either the patient or his environment is moving. The direction is often rotatory.

Unsteadiness: Is a loss of equilibrium in relationship to one's environment. It is often described by the patient as "bumping into things" or "almost falling". The etiology could be cerebellar, cerebral, pyramidal tract, posterior column, or vestibular. A pure labyrinthine etiology seldom gives rise to unsteadiness without vertigo.

Lightheadedness: Is described by the patient as a feeling of "going to faint". It is also used to describe mild vertigo.

The next step when evaluating a "dizzy" patient is to determine the duration of each attack, the frequency of each episode, and whether it is constant, episodic, or related to position. A past medical history of dizziness, no matter how remote, should be taken into consideration when arriving at the diagnosis. It is also imperative to obtain a general medical history to rule in or out diabetes mellitus, hypertension, and other cardiovascular or neurologic diseases.

A complete ENT and neurologic examination which includes observation for spontaneous nystagmus in three directions of gaze, either through Frenzel glasses (+20 lenses) or other methods, is a prerequisite to other studies. Audiometric tests, mastoid and internal acoustic meatus view, caloric tests, or ENG can be obtained if needed. Positional testing is performed if the symptoms are questionably induced or provoked when the patient assumes a particular position. One should note that a sudden change of position may aggravate the symptoms in any type of dizziness without necessarily implying a disease of labyrinthine origin or positional vertigo. A feeling of lightheadedness upon rapidly assuming an upright position does not indicate a labyrinthine or vestibular disorder.

Nystagmus

The slow phase of the nystagmus is the direction of the flow of the endolymph and it is vestibular in origin, whereas the quick phase is most likely initiated by the reticular formation as a compensatory mechanism.

Spontaneous: Nystagmus present without positional or other labyrinthine stimulation. Induced: Nystagmus elicited by stimulation, i.e. caloric, rotation, parallel swings, etc. Positional: Nystagmus elicited by assuming a specific position as in positional testing.

1 Spontaneous Nystagmus

Spontaneous nystagmus can be pendular without a fast or slow phase. Pendular nystagmus usually points to a congenital disorder, ocular disease (Miner's nystagmus) or multiple sclerosis. Labyrinthine nystagmus usually has a fast and a slow phase. By convention, the direction of the nystagmus is determined by the fast component.

Spontaneous dissociated nystagmus is also indicative of central nervous system disease.

Spontaneous rotatory nystagmus is rare although not infrequently observed with a horizontal component during positional testing of patients with positional vertigo of the benign paroxysmal type.

Spontaneous vertical or diagonal nystagmus is very rarely observed. It usually signifies a central nervous system disorder. Vertical or diagonal nystagmus induced by stimulation on positional testing also suggests central disorders.

First-degree spontaneous nystagmus: Nystagmus present only when gazing in the direction of the fast component.

Second-degree spontaneous nystagmus: Nystagmus present when gazing in the direciton of the fast component and on straight gaze.

Third-degree spontaneous nystagmus: Nystagmus present in all three directions of gaze.

Clinical correlation:

1st degree = peripheral lesion

2nd degree = central lesion

3rd degree = central lesion.

When testing for spontaneous nystagmus one should not bring the patient to a complete lateral gaze as this will induce fatigue or "end point" nystagmus. The patient should be tested with eyes in straight gazew, 30-45° to the left and 30-45° to the right.

Spontaneous nystagmus due to peripheral disease can be inhibited by fixation - its manifestation is made possible by eliminating fixation through eye closure or darkness. Spontaneous nystagmus of the central type is present during eye fixation and may be eliminated during eye closure or darkness. When the lesion is below the level of the vestibular nuclei, spontaneous nystagmus is exaggerated by eye closure or darkness. When above this level, spontaneous nystagmus is subdued by eye closure or darkness.

2 Positional Nystagmus

Positional nystagmus is nystagmus elicited during positional testing.

Technique of Positional Testing

1. Sit the patient on a bench in an upright position with arms folded.

2. Reassure the patient that he is not going to fall regardless of his sense of direction. Insist that it is of utmost importance to keep his eyes open during the test.

3. Bring the patient backward swiftly with head hanging. Watch for nystagmus induced by assuming this position. Notice (a) the latency between assuming the position and the onset of nystagmus, (b) the character and direction of nystagmus, (c) the duration of the nystagmus. If the nystagmus has a rotatory component it is classified as clockwise or counterclockwise as illustrated in Fig. 5-1.)

4. Bring the patient back to the upright position either after the nystagmus has stopped or after 3 minutes and determine: (a) the direction of the nystagmus, (b) the duration of the nystagmus.

5. Repeat steps 3 and 4 except that now the head is positioned with the left ear down in step 3.

6. Repeat steps 3 and 4 again except that now the patient's head is positioned with the right ear down in step 3.

The nystagmus elicited can be classified according to Nylen's classification or as modified by Aschan.

Nylen's Classification

1. Type I: The direction of nystagmus varies with the positions of the head in the positional testing.

2. Type II: The direction of nystagmus remains fixed regardless of the position of the head during positional testing. When present in different head positions, the nystagmus is stronger in a particular position.

3. Type III: The nystagmus is irregular, characterized by variations in its behavior. It is thus sometimes direction-changing, sometimes direction-fixed, and sometimes changes its direction with the same head position. Type III is used to label all forms of positional nystagmus that cannot be classified under type I or type II.

3 Clinical Correlation

1. Type I: Implies a cental lesion, i.e. multiple sclerosis or a cerebellar tumor.

2. Type II: Implies peripheral lesion or acoustic neurinoma.

3. Type III: Unknown significance.

Aschan's Classification

1. Type I: The nystagmus is nonfatigable and persistent. Its direction changes with head position.

2. Type II: The nystagmus is nonfatigable and persistent. Its direction remains fixed with change of head position.

3. Type III: ALl varieties of transitory positional nystagmus with latency and fatigue are included.

Clinical Correlation

1. Type I: The majority of these patients have CNS disorder.

2. Type II: Possible end organ lesion, but mainly CNS.

3. Type III: Peripheral disease. Usually indicating positional vertigo of the benign paroxysmal type.

The positional testing has many implications. However, the only practical clinical application to date is to separate positional vertigo of the benigh paroxysmal type from positional vertigo secondary to CNS disease (Table 5-1). Characteristics of positional vertigo of the benign paroxysmal type are:

Table 5-1. A Comparison of the Features of Peripheral and Central Nystagmus

Feature Peripheral Central

Latency 5-15 seconds No latency Persistence Disappears in 50 sec Lasts more than 1 min Fatigability Disappears on repetition Repeatable Position Present in one head position Present in multiple head pos Vertigo Always present Occasionally absent Direction One direction Changing in different head pos Incidence 85% of all positional vert 10-15% of all positional vert.

4 1. The nystagmus elicited is rotatory.

2. If the left ear is the pathologic, the patient will manifest a clockwise rotatory nystagmus when assuming the left ear down position.

3. There will be a latency of 5-15 seconds between assuming that position and the onset of nystagmus.

4. The nystagmus will "fatigue out" (stop after a while).

5. Upon reassuming the upright position, the patient may manifest a nystagmus in the opposite direction.

6. On repeat testing without rest in between, the positional nystagmus can no more be elicited.

Stimulation Tests

Simple Caloric Test

There are many modifications of this test. The important point is that it is a qualitative test measuring the difference in response between the right and left ears. It does not matter which modification of this test is used provided the physician is familiar with the test chosen as well as with its clinical implications and limitations. It is important that the irrigating fluid reaches the tympanic membrane and is not just reflected by the anterior osseous canal or cerumen impaction. This is particularly crucial if small amounts of water are used.

To bring the horizontal canal to a vertical plane for the caloric test, it is necessary to tilt the head back 60° when the patient is in an upright position or elevate the head 30° when the patient is supine.

The test as devised by Kobrak (Kobrak test) used 0.2-5 mL of ice water instilled against the tympanic membrane of the patient in a sitting position with head tilted 60° back. The latency and duration of nystagmus are measured. Other tests include Veit's minimal caloric test, Barany's mass caloric test and Dundas-Grant cold air test for patients with perforated tympanic membrane.

Directional Preponderance

This is a standardized test to measure canal paresis and directional preponderance. To determine directional preponderance Fitzgerald and Hallpike used the following system:

The patient is placed supine with head elevated 30°. Each ear is douched in turn with water at exactly 30°C (86°F) and with water at 44°C (112°F), each douche consisting of no less than 250 mL. At least 5 minutes should elapse between each douche. Directional preponderance is calculated as follows.

5 1. Right ear irrigated with cold H2O: duration of nystagmus to (L) = a.

2. Right ear irrigated with warm H2O: duration of nystagmus to (R) = b.

3. Left ear irrigated with cold H2O: duration of nystagmus to (R) = c.

2. Left ear irrigated with warm H2O: duration of nystagmus to (R) = d.

If a + b is less than c + d, the right ear is hypoactive. If a + d is less than b + c, there is directional preponderance to the right.

Directional preponderance is believed to be toward the side of a central lesion and away from the side of a peripheral lesion.

ENG

This test is based on the difference in potential between the cornea (+) and the retina (-). During nystagmus, movements of the eyes cause this corneal-retinal potential to be displaced laterally giving rise to changes in potential that can be recorded by electronic equipment. This electronic recording of the nystagmus is called electronystagmography or ENG.

1. Electrodes are placed as shown: A, B, C, D, E (Fig. 5-2).

2. By convention and calibration, an upward swing of the pen indicates nystagmus to the right while a downward swing indicates nystagmus to the left.

3. The patient lies supine with the head elevated 30°. He is 8.5 ft from the wall and gazes at points A, B, and C for calibration (Fig. 5-3).

4. Recordings are then taken with eyes open and eyes closed to check for spontaneous nystagmus.

5. ENG recordings can be obtained from the rotation test, positional test, etc.

6. The patient is then irrigated with 250 mL of water at 30°C and 250 mL of water at 44°C in turn as outlined in the Fitzgeral and Hallpike test.

7. The parameters measured by electronystagmography include: intensity (frequency of beats, amplitude of pen displacement, and velocity of slow component) and duration.

Rotation Test

This test stimulates the labyrinth by the force of rotation. It has little clinical application because it stimulates both ears simultaneously.

6 Technique

1. Sit patient up with head brought forward 30°.

2. Rotate the chair at the speed of approximately 10 turns per 20 seconds then stop abruptly.

3. If the subject was rotated to his right, the normal response would be nystagmus to the left with past-pointing to the right. A patient rotated to his right and brought to an abrupt stop undergoes the same effect as beginning a turn to his left, i.e. the quick phase is to the left, slow phase to the right. The direction of the slow phase is that of the flow of the endolymph.

Past-pointing and falling also would be to the right, in the direction of the slow phase. Past-pointing is a compensatory body musculature reflex, its nerve pathways being entirely separate from those of the ocular reflex.

Parallel Swing

Parallel swing tests utricular function and is still a research tool.

Fistula Test

In the presence of a fistula, stimulation of the ear with positive pressure causes nystagmus to the same side while negative pressure brings about nystagmus to the opposite side. The presence of nystagmus may be accompanied by vertigo. However, it is the presence of the nystagmus that is significant in this test. If the patient experiences vertigo without nystagmus of the type mentioned, he could be undergoing a cool caloric stimulation without a positive fistula test. Example: When a fistula is present in the right ear, stimulation of this ear with:

(+) pressure gives nystagmus to the (R) (-) pressure gives nystagmus to the (L).

Optokinetic Nystagmus

Optokinetic nystagmus can be elicited by various methods. One practical way is to have the patient watch a drum 30 cm high by 25 cm in diameter. The surface has 1.5 cm wide white vertical stripes. The drum is rotated about its vertical axis taking 1-2 seconds for a complete revolution. The optokinetic nystagmus is measured while the drum is rotated in one direction. The direction is then reversed and the measurements taken again. When the optokinetic nystagmus is asymmetrical for the two directions of drum rotation, a central lesion is implied. Labyrinthine spontaneous nystagmus can be altered to optokinetic nystagmus by fixation on a rotating drum, whereas spontaneous nystagmus of central origin remains unchanged.

7 Practical benefits of ENG:

a. To record spontaneous nystagmus and positional nystagmus with eyes open and eyes closed.

b. To record caloric responses.

c. To study optokinetic nystagmus (eye-tracking is still nonclinical).

Differential Diagnosis

When evaluating a patient with vertigo, one should try to differentiate between vertigo of peripheral origin and that of central origin (Table 5-2).

Table 5-2. Comparison of Vertigo of Peripheral Origin with That of Central Origin

Peripheral

--> Central

A definite sensation of movement is present.

--> Vertigo is mild and more like a sensation of unsteadiness.

Verigo is severe and paroxysmal.

--> Vertigo is vague with no specific onset or termination.

Attacks last from minutes to days; are accompanied by spontaneous nystagmus and associated with autonomic nervous system disorders; patient almost never loses consiousness.

--> Attacks of vertigo last for weeks, often with no apparent nystagmus.

The following list of differential diagnoses constitutes the more common etiologies of the "dizzy" patient:

1. Ménière's disease.

2. Acoustic neurinoma.

3. Vestibular neuronitis.

4. Bacterial labyrinthitis.

5. Nonbacterial "labyrinthitis".

6. Positional vertigo of the benign paroxysmal type.

8 7. Congenital syphilis.

8. Cogan's syndrome.

9. Vertigo due to whiplash injury.

10. Temporal bone fracture and labyrinthine concussion.

11. Multiple sclerosis.

12. Vascular insufficiency.

13. Cervical vertigo.

14. Vertiginous epilepsy.

Ménière's Disease

The medical history of Ménière's disease is usually typical. The patient suffers episodic vertigo lasting from 30 minutes to 2 hours. The attack is associated with nausea, vomiting, and prostration. The patient may experience fluctuating hearing loss, tinnitus, and a sensation of fullness in the affected ear or ears during an attack of vertigo. After a severe attack, patients may feel lightheadedness for half a day or so but they are completely well by that evening or the next day. In the early stage of the disease, the episodic vertigo may occur once every yar or so but sometimes as far apart as 5-10 years. In most patients the disease affects only one ear (85%). Should the second ear be involved, it usually happens within 36 months.

Diagnostic labyrinthotomy through the oval window may reveal the characteristics of endolymph rather than perilymph. However, the fluid obtained from the round window is perilymph.

Audiometric testing will document fluctuating hearing loss usually in the low frequencies with high SISI score, type II Bekesy, and little or no tone decay. Caloric testing or ENG will demonstrate hypofunction of the vestibular labyrinth in the affected ear.

Crisis of Tumarkin

This is a variant of Ménière's disease in which the patient loses his extensor powers and falls to the ground during a sudden, severe, and short episode of vertigo. He is completely conscious throughout this episode and recovers promptly afterwards.

Lermoyez's Syndrome

This is generally agreed to be a rare variant of Ménière's disease in which there is a dramatic restoration of hearing after an episodic attack of vertigo. Recurrence of this phenomenon can be expected.

9 Glycerol Test

It has been speculated that administration of glycerol in the dose of 1.2 mL/kg of body weight with addition of an equal amount of physiologic saline, to a patient with Ménière's disease with sensorineural hearing loss, tinnitus, and sensation of fullness in the ear, has improved the symptoms within an hour with maximum effects in 2-3 hours. After 3 hours, the symptoms slowly return.

Acoustic Neurinoma

Acoustic neurinoma accounts for 80% of angle tumors. Most patients with acoustic neurinomas complain of unsteadiness rather than episodic vertigo. However, it has been reported that about 10% of acoustic neurinoma patients presented with episodic vertigo of Ménière's type.

Classically, the caloric reaction is markedly depressed. Audiometric studies reveal a high frequency hearing loss in many of the cases. However, other audiometric patterns are not uncommon. The patients usually have a disproportionately low discrimination score, low SISI score, high tone decay score, and type III or type IV Bekesy score. Definitive diagnosis of this disease is made from x-rays of the internal auditory canal.

Vestibular Neuronitis

Vestibular neuronitis, of which 50% is unilateral and 50% bilateral, usually follows an upper respiratory tract infection. A patient experiences a sudden onset of vertigo with nausea, vomiting, the sensation of blacking out accompanied by severe unsteadiness. This severe attack can last from days to weeks. Cochlear symptoms are surprisingly absent and without associated neurologic deficits. When seen initially, the patient has spontaneous nystagmus to the contralateral side. A caloric test would show marked hypofunction of the labyrinth. Audiometric tests and x-rays of the internal auditory canal are within normal limits.

After the acute episode has subsided, which may take weeks, the patient continues to experience a slight sensation of light-headedness for some time, particularly in connection with sudden movements. In some patients, there may be an exacerbation of the acute attack within 3-6 months. The caloric reaction may remain mildly hypoactive for the duration of the patient's life. The acute episode may also be followed by a period of positional vertigo of the benign paroxysmal type.

Bacterial Labyrinthitis

This is usually a complication of an ear infection which makes the diagnosis obvious.

Nonbacterial "Labyrinthitis"

Some patients have presented with a sudden attack of vertigo associated with nausea, vomiting, and sensorineural hearing loss without a previous history of vertigo. There is no associated neurologic deficit. Is this the first attack of Ménière's disease, or does the patient have an acoustic neurinoma? Perhaps it is viral labyrinthitis or thrombosis of one of the

10 labyrinthine vessels? Should one consider the possibility of a round or oval window rupture? A careful evaluation and long follow-up may reveal the mystery.

Cupulolithiasis

Cupulolithiasis is a term used by Schuknecht to designate positional vertigo of the benign paroxysmal type. The symptoms include sudden attacks of vertigo precipitated by certain head positions. These attacks have been reported to be prompted by sudden movement of the head to the right or left or by extension of the neck when looking upward. The sensation of vertigo is always of short duration even when the provocative position is maintained. Diagnosis can be confirmed by positional testing which will indicate positional nystagmus with latency and fatigability.

Etiologies include degenerative changes, otitis media, labyrinthine concussion, previous ear surgery, and occlusion of the anterior vestibular artery. Histopathologically, otoconia has been found deposited in the posterior semicircular canal ampulla. It is probable that some of these deposits have resulted from postmortem degeneration of the utricular otolithic membrane. Treatment of this disease is symptomatic and by reassurance.

Congenital Syphilis

The majority of these patients develop hearing loss during young adulthood. This hearing loss is of a flat sensorineural type. When the onset of hearing loss occurs in adulthood, the loss in both ears is asymmetric and fluctuates with the episodic vertigo and tinnitus. However, when the onset occurs in childhood, the hearing loss is abrupt, bilaterally symmetric, and more severe.

Acquired syphilis seldom leads to hearing loss but neurosyphilis and congenital syphilis (38% of congenital syphilis) frequently give rise to hearing loss, with bilateral hearing loss being more prevalent than unilateral hearing loss. Vertigo in congenital syphilis is episodic, similar to Ménière's disease.

These patients usually have a positive Hennebert's sign, i.e. postive fistula test without any demonstrable fistula along with a normal external auditory canal and tympanic membrane. The positive fistula test indicates an abnormally mobile footplate. The patient also may demonstrate Tullio's phenomenon (see Chaps. 8 and 23.)

Histopathologically, mononuclear leukocytic infiltration is evident with obliterative endarteritis. Inflammatory fibrosis and endolymphatic hydrops are present. Osteolytic lesions are often seen in the otic capsule. Interstitial keratitis is another common manifestation of congenital syphilis.

Cogan's Syndrome

(See Chap. 23: Syndromes and Eponyms).

11 Vertigo Due to Whiplash Injury

Patients often complain of dizziness following a whiplash injury. In some cases, there is no physiologic evidence for this complaint. In others, ENG has documented objective findings such as spontaneous nystagmus. The onset of dizziness often occurs 7-10 days following the accident, particularly upon head movements toward the side of the neck most involved in the whiplash. The symptoms may last for months or years after the accident.

Otologic examination is usually normal. Audiometric studies are normal unless there is associated labyrinthine concussion. Vestibular examination can reveal spontaneous nystagmus or positional nystagmus with the head turned in the direction of the whiplash. The use of ENG is essential in evaluating these patients.

Temporal Bone Fracture and Labyrinthine Concussion

Transverse Fracture

Since a transverse fracture destroys the auditory and vestibular function, the patients have no hearing or vestibular response in that ear. When seen initially, they present with spontaneous nystagmus to the contralateral side and are severely vertiginous, very much like a recently postoperative labyrinthectomized patient. The severe vertigo subsides after a week or so and the patients remain mildly unsteady for 3-6 months depending on their age and athletic inclination. The patients also may have labyrinthine concussion in the opposite ear. During the acute phase, they usually fall toward the involved side.

Longitudinal Fracture

Longitudinal fracture constitute 80% of the temporal bone fractures. In this type of fracture, there is usually bleeding into the middle ear, with perforation of the tympanic membrane and disruption of the tympanic ring. Hence, the patient has a conductive hearing loss as well as a sensorineural high-frequency hearing loss fro the concomitant labyrinthine concussion. Dizziness is mild and there may be no vertigo exceopt during positional testing.

Labyrinthine Concussion

Labyrinthine concussion is secondary to head injury. The patient complains of mild unsteadiness or light-headedness particularly with change of head position. Audiometric testing reveals a high-frequency hearing loss. The ENG may show spontaneous or position nystagmus; occasionally, the caloric response is hypoactive.

Multiple Sclerosis

Multiple sclerosis is one of the more common neurologic diseases encountered in a clinical practice. Vertigo is the presenting symptom of multiple sclerosis in 7-10% of the patients or eventually appears during the course of the disease in up to one-third of the cases. The patient usually complains of unsteadiness along with vertigo. Diagnosis of the disease depends on other signs of demyelination. Vertical nystagmus, bilateral internuclear

12 ophthalmoplegia, and ataxic eye movemnts ar other clues to this disease. Charcot's triad (nystagmus, scanning speech, intention tremor) may be present.

Vascular Insufficiency

Vascular insufficiency can be a common cause of vertigo among the over 50-year-olds as well as in patients with diabetes, hypertension, or hyperlipidemias. The following syndromes have been recognized among patients with vascular insufficiency:

Labyrinthine Apoplexy

Labyrinthine apoplexy is due to thrombosis of the internal auditory artery of one of its branches. The symptoms include acute vertigo with nausea and vomiting. Hearing loss and tinnitus may or may not occur.

Wallenberg Syndrome (Also see Chap. 23)

Wallenberg's syndrome also is known as the lateral medullary syndrome secondary to infarction of the lateral portion of the medulla which is supplied by the posterior inferior cerebellar artery. This syndrome is believed to be the most common brain stem vascular disorder. The symptome include:

1. Vertigo, nausea, vomiting, nystagmus.

2. Ataxia, falling toward the side of the lesion.

3. Loss of the sense of pain and temperature sensations on the ipsilateral face and contralateral body.

4. Dysphagia with ipsilateral palate and vocal cord paralysis.

5. Ipsilateral Horner's syndrome.

Subclavian Steal Syndrome (Also see Chap. 23)

The subclavian steal syndrome is characterized by intermittent vertigo, occipital headache, blurred vision, diplopia, dysarthria, pain in the upper extremity, loud bruit or palpable thrill over the supraclavicular fossa, a difference of at least 20 mm Hg in systolic blood pressure between the two arms, and a delayed or weakened radial pulse. The blockage can be surgically corrected.

13 Anterior Vestibular Artery Occlusion

The symptoms include:

1. Sudden onset of vertigo, without deafness.

2. Slow recovery followed by months of positional vertigo of the benign paroxysmal type.

3. Histologically, utricular macula, the cristae of the lateral and superior semicircular canals and the superior vestibular nerve show signs of degeneration.

4. This symptom complex was first described by Lindsay and Hemenway in 1956.

Basilar-Vertebral Insufficiency

The symptoms include vertigo, hemiparesis, visual disturbances, dysarthria, headache, and vomiting. These symptoms are a result of a drop in blood flow to the vestibular nuclei and surrounding structures. The postero- and anteroinferior cerebellar arteries are involved. Tinnitus and deafness are unusual symptoms.

Drop attacks without losing consciousness are characteristic of basilar-vertebral insufficiency. These drop attacks can be precipitated by neck motion.

Cervical Vertigo

Cervical vertigo can be caused by cervical spondylosis as well as by other etiologies. Cervical spondylosis in turn can be brought about by degeneration of the intervertebral disc. As the disc space narrows, approximation of the vertebral bodies takes place. With mobility, the bulging of the annulus is increased causing increased traction on the periosteum to which the annulus is attached and stimulating proliferation of bone along the margins of the vertebral bodies to produce osteophytes.

Barre believed that the symptoms of cervical spondylosis (including vertigo) are due to irritation of the vertebral sympathetic plexus, which is in close proximity to the vertebral artery. Laskiewicz claims that spondylosis irritates the periarterial neural plexus in the wall of the vertebral and basilar arteries leading to contraction of the vessels. Temporary ischemia then gives rise to vertigo. Others claimed that the loss of proprioception in the neck can give rise to cervical vertigo. Emotional tension, rotation of the head, and extension of the head can cause the neck muscle (including the scalenus anticus) to be drawn tightly over the thyrocervical trunk and subclavian artery, compressing these vessels against the proximal vertebral artery. In elderly individuals a change from the supine to the upright position may give rise to postural hypotension which in turn may cause vertebral-basial insufficiency. The aortic arch syndrome and subclavian steal syndrome also may cause cervical vertigo.

14 Symptoms

1. Headache, vertigo.

2. Syncope.

3. Tinnitus and loss of hearing (usually low frequencies).

4. Nausea and vomiting (vagal response).

5. Visual symptoms such as flashing lights are not uncommon. This is due to ischemia of the occipital lobe which is supplied by the posterior cerebral artery, a branch of the basilar artery.

6. Physical examination may reveal a supraclavicular bruit in one-third of the patients.

All of the above symptoms usually appear when the head or neck assumes a certain position or change of position.

Treatment

Proper posture, neck exercises, cervical traction, heat massage, anesthetic infiltration, and immobilization of the neck with a collar temporarily are all good therapeutic measures. If traction is required it can be given as a few pounds horizontally for several hours at a time. In cervical spondylosis without acute root symptoms, heavy traction (100 lb) for 1-2 minutes continuously or 5-10 minutes intermittently is considered by some as more effective.

Vertiginous Epilepsy

Cortical vertigo can either be severe and episodic like Ménière's disease, or may manifest as a mild unsteadiness. It is usually associated with hallucinations of music or sound. The patient may exhibit "daydreaming", and purposeful or purposeless repetitive movements. Motor abnormalities such as chewing, lip smacking, and facial grimacing are not uncommon. The patient may experience an unusual sense of familiarity (deja vu) or a sense of strangeness (jamais vu). Should the seizure discharge spread beyond the temporal lobe, grand mal seizures may ensue.

Vertigo in Migraine

Vertebral-basilar migraine is due to impairment of circulation of the brain stem. The symptoms include vertigo, dysarthria, ataxia, paresthesia, diplopia, diffuse scintillating scotomas, or homonymous hemianopsia. The initial vasoconstriction is followed by vasodilatation giving rise to an intense throbbing headache, usually unilateral. A positive family history is obtained in over 50% of these patients. Treatment of migraine includes Fiorinal, ergot derivatives, and methysergide (Sansert). (Sansert has the tendency to cause retroperitoneal fibrosis.)

15 Miscellaneous

Streptomycin

Streptomycin sulfate is believed to destroy the cristae of the semicircular canals and not the maculae of the utricle and saccule.

Ewald's Law

1. When a semicircular canal is stimulated, it tends to elicit nystagmus in its own plane.

2. The horizontal semicircular canal is maximally stimulated by an ampullopetal flow (i.e. endolymph directed towards the ampulla). The superior semicircular canal and posterior semicircular canal are maximally stimulated by amullofugal flow (i.e. endolymph directed away from the ampulla).

3. When a semicircular canal is maximally stimulated, it elicits a quick phase of nystagmus to its own side.

Coriolis Forces

Any body which is set in motion off the surface of the earth towards a distant earth target is deflected from a straight course because the earth is rotating. When a subject is on a machine which is rotating at a steady velocity, any movement of the body, head, or limbs that are made about an axis different from, and at an angle to, that of the machine, generates extra forces, some of which are also described as Coriolis forces or acceleration.

Coriolis Phenomenon

When the subject's head is tilted about an axis which is perpendicular to the main axis of rotation, spatial disorientation will be experienced.

Internuclear Ophthalmoplegia

Internuclear ophthalmoplegia is a disturbance of the lateral movements of the eyes, characterized by a paralysis of the internal rectus on one side and weakness of the external rectus on the other side. In testing, the examiner has the patient follow his finger, first to one side, and then to the other, as in testing for horizontal nystagmus. Internuclear ophthalmoplegia is recognized when the adductive eye (III nerve) is weak while the abducting eye (VI nerve) moves normally and displays a coarse nystagmus (? vestibular nuclei involvement). The pathology is in the medial longitudinal fasciculus. When the disorder is bilateral it is pathognomonic of multiple sclerosis, when unilateral, one should consider a tumor or vascular process.

16 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 6: Speech, Language, and Voice

Communication, the exchange of verbal or written messages between man, includes the expression and comprehension of symbols or the process of encoding and decoding.

This exchange is made possible through the parameters of speech, language, voice, and hearing.

Speech

Speech is the mechanical aspect of communication. One must consider the physiology of respiration, phonation, resonation, and articulation, when appreciating the necessity and complexity of the system of speech.

Upon the expiration of air from the lungs, the vocal folds of the larynx are set into vibration and produce cound. Thus the larynx may be considered the source of sound. The sound travels up the vocal tract and resonates off the walls of the pharynx, oral cavity and, in the case of nasal sounds, such as /m/, /n/, and /ing/, resonation will occur to a great extent in the area of the nasal cavity. At this point the sound is still nondifferential and generally carries little meaning as a symbol. The action of the articulators, however, shapes and modifies the sound waves into consonants and vowels, which are coarticulated or blended to produce or express the smallest components of communication. These components, or morphemes, are the symbols learned and recognized to carry specific meaning.

Misarticulation

Speech disorders are most salient to the pediatric population, but, if left untreated, carry over into adulthood. A child may substitute one sound for another in a word (thoup for soup) or the production of a sound may be distorted (as in the same example of the word "soup", the /s/ may be slurred or otherwise altered), in either case creating confusion in the listener or destroying the meaning of the word. A child also may completely omit a sound. (If the final /p/ were omitted, "soup" would then become a woman's name and not something to eat.) Finally, a child may add a sound that does not belong to aword, for instance, adding an /a/ sound to our example would give the word an accentuated pronounciation. Thus we can see that the substitution, distortion, omission, and addition of sounds when articulated in words, can most definitely affect the word itself, altering its meaning or making it unintelligible. These speech disorders are commonly referred to as misarticulations and can occur to one or may sounds consistently, in either the initial, medial, or final positions of words. The greater the misarticulation, the more unintelligible speech becomes.

It should be noted that a child will not develop all the sounds of a language at once, but establishes the correct pronounciation over time. Certain sounds appear during specific stages of development. By 3years old, the child would have acquired the following vowels and diphthongs: e, i, e, a, o, u, oo, ooo, o, a, ur, u, a, i, ou, oi. At this stage, 75% of all children would be ablce to produce the following consonants correctly: b, d, f, g, h, k, m, n, p, t, w. Mastery of double and triple consonant blends would be complete by the time they

1 are 4.5 years old.

A prerequisite for proper articulation is adequate hearing acuity. Therefore, upon the referral of a child to a speech/language pathologist by a pediatrician, parent, or schoolteacher for a spech evaluation, the child's hearing ability must be assessed before any speech testing. Assuming this has been done by an audiologist, the spech/language pathologist may then conduct an evaluation of the subject's articulatory skills through articulation testing and an examinaiton of the speech musculature structure (teeth, tongue, lips, hard and soft palate) through an oral-peripheral examination. The results are then studied and proper recommendations are made. A program of therapy would include the correction of each misarticulated sound in isolation as well as in syllables, words, and sentences, with the final goal being the correct pronounciation of the sound in connected speech.

Dysarthria

An impairment of speech usually affecting the adult population is known as dysarthria. It is characterized by a slurred, sometimes thick speech, which, depending upon its severity, may either make the speech slightly abnormal or totally unintelligible. Dysarthria is oftentimes caused by a stroke, but could result from a mere lack of dentures. The speech/language pathologist, following an evaluation of the person's communicative ability, and through a program of therapy will stress slow speech, exaggerated movement of the speech musculature compensatory to the degree of weakness, and self-auditory monitoring.

Apraxia

Another speech impairment that occurs with a cerebral vascular accident or other neurological problem is known as apraxia and is characterized by substitutions and additions of sounds in words. This is similar to a child's misarticulation in its representation; the difference being that the child has never really learned the proper production of a sound, while the adult has simply forgotten the proper coordination of the speech musculature necessary for producing a sound. Retraining for affected sounds in isolation and later on the word level, is the therapeutic goal in such cases. Once again, proper hearing acuity is of utmost importance if the person is to feed back the sound production and measure it for accuracy.

Stuttering

A speech disorder that affects the communicative ability of many ages, childhood through adulthoo, is a disorder of speech timing known as stuttering. It may be characterized by hesitations, repetitions, or prolongations of a sound, word, or phrase. These dysfluencies may be accompanied by secondary behavioral characteristics such as eye blinking, head jerking, or twitching of some kind that seem to develop and be habitually retained as an aid to the production of a sound or word. The cause of stuttering is largely unknown. Some of the theories explain the stammered speech to result from an organic condition, a delay in auditory feedback, or a learned behavior. The speech/language pathologist will analyze the stuttering in depth, then begin therapy. Strategies are geared toward teaching the patients to self-monitor and control their speech in a step-by-step fashion, until they can correctly form sounds, syllables, words, and sentences in a slow, positive, confident manner.

2 Language

According to Webster's dictionary, language may be defined as the "expression of ideas by words or written symbols". Symbols of gesture, as in sign language, also express ideas. In addition, clear messages can be sent through facial expressions or body movement, as well as through specific intonation patterns, via the voice. Simply stated then, symbols can be sent and received through various devices, predominantly verbal, graphic, and gestural.

Language is learned receptively in the first instance. If the infant's hearing mechanism is intact, it is used to capture the words heard, storing large reservoirs of symbols. Once the functions of respiration, phonation, and articulation are coordinated, sounds begin to emerge expressively. These carry distinc meanings, expressing ideas of hunger, pain, discomfort, amusement, and contentment. They occur again and again and develop into meaningful words as the basic utterances are understood and positively reinforced, first by our own auditory skills and then by the listener.

Table 6-1. Sequence of Linguistic and Auditory Milestones in Relation to Age

1 Alerting 1-1.5 Social smile 3 Cooing 4 Orientation to voice 5 Orients to direction of bell sound 5 "Ah-goo" 5 Razzing 6.5 Babbling 7 Orients to direction of bell sounds then locates bell 7.5 Gesture 8 "Mama/Dada" (inappropriately) 9.5 Orients and locates bell sound immediately 10 "Mama/Dada" (appropriately) 11 One word 12 One-step command (with gesture) 12 Two words 14 Three words 15 One-step command without gesture 15 Four to six words 15 Immature jargoning 18 Seven to 20 words 18 Mature jargoning 18 Identifies one body part 21 Identifies three body parts 21 Two-word combinations 23 Identifies five body parts 24 50 words 24 Two-word sentence 24 Use of pronouns (I, me, you; inappropriately).

3 As in the case of the development of sounds, there is a correlation between the development of receptive and expressive terms and other developmental stages (Table 6-1). This development will only take place in a normal sequence if the function of audition is present, including the normal functioning of the ears' anatomy and physiology from pinna to the auditory cortex.

Disorders of Language

Some children have most conditions intact, but still learn language at a rather slow speed. They are usually categorized as being language delayed. They may be missing a functional language model, be that the parent, television, or sibling. Oftentime these children manifest an overall developmental delay, but they are not considered organically retarded. Rather, the term "environmentally deprived" is generally supplied.

Some children lack the ability to effectively experience and process a receptive stimuli and tend to repeat what is said to them as in the case of echolalia. This is accompanied by a delay in the development of expressive vocabulary. Others, for various reasons, never develop language on their own and are considered nonverbal.

A physical handicap like cerebral palsy can prevent a child from learning language in a normal way. These children usually live their lives in a limited environment and are usually overprotected, further limiting learning experiences and, hence, language development. Many times these children also have speech and hearing difficulties. It should be noted that children who are bilingual or multilingual may sometimes show a delayed language development because they are really learning two or more languages at one time.

To monitor language development effectively, hearing acuity must be tested (and the mechanism aided if necessary) by an otologist and audiologist, respectively. Then, as language develops, it must be tested at intervals, receptively and expressively, considering all modalities: verbal, graphic, gestural, and visual. Measurements are made and usually matched against developmental norms to determine just how much language the individual has and how muchg deviation is considered normal. The cause for deficient development may not be readily apparent and may require deeper investigation to seek out such malfunctions as short auditory or visual attention spans, visual and/or auditory closure problems, or behavioral problems. Once the investigation is completed, recommendations are made and individualized therapy programs are designed with a goal of bringing linguistic skills to as near a normal level as is possible. Successful intervention in a language-impaired individual generally calls for an investigation by a team of professionals.

In the case of the adult, we can assume that most language problems are the result of some neurologic deficit, incurred once normal language development has been completed. Head trauma, cerebral vascular accident, hemorrhage, or tumor will cause specific areas of the brain (Broca's or Wernicke's area of the left hemisphere in most instances) to be damaged and not function properly. The dysfunction generally involves the decoding of incoming linguistic stimuli as in receptive aphasia and/or the inability to encode outgoing linguistic stimuli as in expressive aphasia.

4 Once referred to a speech/language pathologist, the brain-injured patient with normal or aided hearing acuity would be screened or be given a deep language evaluation, assessing the skill of all expressive and receptive modalities. When the differential diagnosis has taken place, the caregiver will develop a program of word retrieval with a goal of bringing the patient to a level of communicative ability that is at least functional, if not very near normal.

Voice

Voice or phonation is considered sound. This sound is produced by the vibration of the vocal folds, which are set in motion by the expiration of air from the lungs with the aid of subglottic pressure which builds just before the initiation of vibration. The various frequencies or tone pitches of the voice may be altered or modified by the action of the laryngeal cartilages and intrinsic and extrinsic muscles of the larynx. Frequencies are considered "optimal" for adult males at about 125 Hz, and for adult females at 225 Hz (Harryman E et al, 1978).

A voice within the ranges of what is considered optimal has a clear sound quality, a volume strong enough to be heard under normal circumstances, and has a resonance that sounds evenly balanced between the larynx, pharynx, oral cavity, and nasal cavity. A voice that call attention to itself or is perceived as different auditorially may sound harsh, hoarse, or breathy in quality, may be too soft or weak so that listeners must strain to hear the message, have an inappropriate pitch, as in the case of abnormally low-pitched female or abnormally high-pitched male, or a resonance that seems restricted to the laryngeal or to just the nasal cavities. Therefore, voices that fall outside the perception of what is considered normal may fall into certain classifications according to the features of intensity, pitch, and quality.

Disorders of Intensity

The problem of intensity can be very serious communicatively; in the extreme it is manifested by the total lack of voice or aphonia, which may arise from an emotional problem or stress factors, as in the case of hysteric aphonia. The loss of voice in this situation usually begins suddenly: in the middle of a sentence the individual may find it impossible to complete his message verbally. This condition may seem to originate with a cold or laryngitis, but often it is associated with deep emotional conflict. Upon examination the physicianwill usually find no organic pathology, or possibly observe a bowing of the folds upon phonation, whereas abduction may occur too easily. Approximation of the vocal folds may occur, however, in conjunction with the acts of coughing or clearing the throat. Aphonia is also the direct result of a laryngectomy.

Dysphonia refers to the partial loss of voice. Spastic dysphonia occurs when an individual emits some words of a sentence clearly and with ease, then struggles to produce sound for the remainder. Many times this syndrome may be perceived auditorially, as in stuttering. Automatic speech, singing, or nonmeaningful asides may be expressed easily, but all meaningful utterances may be accompanied by tension and strain, along with their resulting distortions. Besides functional causes, such as vocal abuse and misuse, this condition also may be associated with CNS diseases, such as cerebral palsy.

5 Disorders of Pitch

Pitch disorders are manifested by frequencies that are too high or too low (most common) for the individual's age and sex, or those with little or no inflectional pattern, many times due to fatigue, boredom, depression, or an improper use of pitch. Also included are pitch breaks to a higher or lower frequency, falsetto voice, or the use of a very high pitch, and the less common tremulous voice or quavering speech due to fear, anxiety, or organically, to athetoid cerebral palsy.

As in the case of the bass strings on any string instrument, the thicker the mass of the vocal cord, the lower the pitch. Therefore, if mass is added to the cord, the result will be a lower-than-normal-pitched voice. Mass can be added by edematous folds or the growth of nodules or polyps. When the vocal folds vibrate over the lower part of the pitch range, creating a bubbly, cracking sound, it reveals the presence of a voice problem known as glottal fry. Conversely, the vocal folds are tightened by such conditions as tension, fear, and stress. These, as well as trying to speak louder, will make the folds thinner or reduce their normal mass and abnormally raise the pitch. Organic causes for this condition may occasionally be found. These include a laryngeal web or abnormal approximation of the folds. Use of too high a pitch may cause vocal fatigue, nodules, or myasthenic laryngitis.

Another pitch problem is referred to as a falsetto. Boone describes the physiology as follows:

"... the folds approximate with posterior vocal process adduction. The posterior cartilage portion is so tightly adducted that there is little or no posterior vibration. The lateral portions of the thyroarytenoid muscles are not contracted. The inner vocalis section is extremely tightened and contracted around the vocal ligament; the glottal edge is extremely thin and is the primary vibratory structure during falsetto." (Boone, 1971, pp. 34-35).

Causes for this condition may be the underdevelopment of the laryngeal mechanism, endocrine dysfunctions, fears that go with assuming the responsibilities of adulthood, or an avoidance of other deviant voice or speech problems such as stuttering or pitch breaks.

Pitch breaks are sudden variations in pitch from low to high or high to low and many times break in a direction of the optimal or appropriate pitch of the speaker. Boone (1971) suggests that those experiencing pitch breaks are usually employing an habitually unstable pitch that is either too high or too low, resulting in a break.

Disorders of Quality

The quality of voice often is affected by disorders of phonation, characterized by harshness, breathiness, and hoarseness. Atypical laryngeal size, edema, laryngeal growths, and laryngeal paralysis are among the organic factors, while vocal abuse and misuse may contribute to a functional origin. Common types of vocal abuse may be screaming, yelling, throat clearing, cigarette smoking, coughing, excessive talking, strained vocalizations, and talking in the presence of loud noise. Vocal misuse may be best defined as the incorrect use of pitch and volume. An added causative factor is vocalfold approximation problems: under and over approximation may cause the above-stated vocal qualities. Voice disorders of

6 resonance include mainly hyper- and hyponasality, where too much or too little sound is resonated by the nasal cavity walls. There are only three sounds that require the degree of nasality produced by an open velopharyngeal port: /m/, /n/, and /ing/. These occur approximately 11% of the time in connected speech.

Hypernasality may be caused by velopharyngeal incompetence resulting from inadequate function or structure. The absence of tissue necessary to effect proper closure as in a cleft or short palate, or the result of tumors, or surgery to remove adenoids, may all contribute to hypernasal speech. Any tears or perforations of the bony palate or velum because of injury or trauma also may contribute to hypernasal speech. Hyponasality, or the lack of resonance for the three sounds /m/, /n/, /ing/, may result from a partial or complete obstruction in the nasal tract.

Upon any voice referral to the speech/language pathologist a complete case history is always the first order of business. The sound of the patient's voice is analyzed in the course of the verbal question-and-answer period, usually accompanying the development of a case history. This is retained on tape and is further analyzed as to the nature of the voice disorder, its duration, and previous means of intervention. The clinician will take an in-depth look into the patient's total life-style in an effort to detect possible misuses or abuses of the voice. A therapy program will generally direct itself toward eliminating vocal abuse, teaching the patient a correct oronasopharyngeal resonance balance, locating and maintaining an optimal pitch, and working with correct breathing patterns and relaxation techniques.

The most devastating voice disorder, cancer of the larynx, leaves the patient with no voice. Following the surgical removal of the larynx, the speech/language pathologist will offer the patient alternate means of communication via an electrolarynx and instruct the patient on its most effective use until the patient's communicative ability is considered functional and adequate by the clinician. When the laryngologist deems the patient ready to learn esophageal speech, the speech/language pathologist will begin to teach the patient to produce a burping or belching sound upon command. A progression of instructive levels will follow until the patient produces the sound consistently and stretches it in length to form words, phrases, then sentences. Via a new sound source - the vibration of the esophageal walls - the laryngectomized individual can communicate clearly once again.

Another means of sound production for use by the laryngectomized individual occurs following a tracheoesophageal (TE) puncture, which directs pulmonary air into the esophagus by means of valved voice prosthesis. Severe different types of prostheses are currently being developed and perfected by laryngologists and speech/language pathologists working together.

The TE prosthesis provides a laryngectomee communication that is more natural and fluent.

Miscellaneous

Speech Sounds

Speech sounds are generally classified as consonants, vowels, or diphthongs. Vowel sounds are produced by a modification in size and shape of the resonating cavities without

7 obstruction or interference with the breath stream. Consonants are speech sounds which are produced with some degree of restriction or obstruction of the breath stream by the organs of articulation. Diphthongs are vowel-like sounds made by gliding two vowels together. The most common diphthongs are: (aI) as in ice, (oI) as in boy, (aU) as in house, (eI) as in bay, (oU) as in hoe. Consonants are often classified according to:

1. Place of articulation.

2. Manner of articulation.

3. Element of vocalization.

The place of the production of sound, that is the locus of the blockage, constriction, or diversion of the air stream may be designated as follows: labial (p, b, m, w); labiodental (f, v); linguadental (voiced and unvoiced th); alveolar (t, d, n, l); postdental (s, sh, z, zh); palatal (y as in yellow, r as in red); velar (k, g, ng); glottal (h).

When classifying consonants according to the manner of articulation, the terms plosive, fricative, affricate, nasal, lateral, glide, and semivowel are used.

Plosives

Plosives are produced by stopping and then suddenly releasing the stream of breath. The plosive sounds are (p, b, t, k, g).

Fricatives

Fricatives are produced by a partial closure of the articulators which results in the creation of a restricted passage of the breath stream. This may take place as a result of grooving of the tongue or by having other organs of articulation come close together. The fricative sounds of speech are (f, v, voiced and unvoiced th, s, z, zh, and h).

Nasal Sounds

Nasal sounds are those which are emitted through the nose rather than the mouth. The nasal sounds in American speech are (m, n, ng).

Affricates

Affricates are blends of two sounds, one of which is a fricative and the other of which is a plosive. The affricates are (ch, dzh).

Lateral Speech

The lateral speech is produced by having air emitted at both sides of the tongue or the tip of the tongue is in contact with the gum ridge. The only lateral sound in American speech is the /l/ sound.

8 Glide

A glide consonant is characterized by a continuous movement of the articulator or articulators while a sound is being made. The glide consonants include (w, y as in yellow, and r as in red).

Semivowel

The semivowel is related to the glide in that there is movement involved in its consonant function. The semivowels are (w, r, y as in yellow, and l). The element of vocalization as a means of classifying consonants depends upon whether the vocal folds are in vibration when the sound is produced. If they are, the sound is said to be voiced and if it is not, the sound is said to be unvoiced. A labiodental voiced fricative would describe the consonant /v/ is produced during the three factors of place, manner, and vocalization.

Cleft Palate and Adenoidal Speech

Two types of speech problems which are frequently seen by the otolaryngologist are associated with abnormal nasal resonance. The nasality is "hyper" if there is too much and "hypo" if there is too little.

In the case of a normal speaker, the soft palate effectively seals off the nasal cavity for most sounds, but allows the nasal sounds (m, n, ng) to pass through the nose. For the cleft palate speaker who has insufficient velopharyngeal closure, all sounds tend to pass through the nose and the speech becomes hypernasal. Both vowels and consonants are adversely affected. The vowels are given excessive nasal resonance and hence sound distorted. The most common articulatory error is the substitution of some nasal equivalent for the plosive and fricative sounds. The voiceless plosives (p, t) are usually preceded by a sharp nasal puff and a pinching of the nostrils. The velar plosives (k, g) are among the most difficult to make since they require an air pressure buildup behind the tongue. This is virtually impossible without sealing off the nasal cavity. Fricative sounds usually are accompanied by nasal snorts. The nasal snort frequently is substituted for the s and sh. This type of speech may, in severe cases, be extremely unintelligible. Good test words to show velopharyngeal insufficiency are cool, coca cola, quack quack.

The hypernasality and articulatory problems associated with cleft palate speech also occur when there is no actual cleft of the palate. It may occur with a soft palate that is paralyzed, sluggish, or too short. A child with a short palate may be able to avoide excessive nasality by compensating with hypertrophied adenoid tissue. However, if the adenoidal tissue is removed surgically, hypernasality may result. For this reason, surgical removal of adenoidal tissue should be given careful consideration prior to this undertaking.

Adenoidal Speech

Hyponasality (or denasality) is often called "cold in the nose" speech. It is primarily a substitution of (b, d, g) for the nasal (m, n, ng). The quality of other sounds is also somewhat affected. Hyponasality is usually associated with some structural pathology such as hypertrophy of the adenoids or polyps.

9 Outline

Speech, Language, Voice

Introduction on Communication

Components: Speech Language Voice.

I. Speech

A. Definition: Mechanical aspect of communication. The forming of sounds and words etc on phonation.

B. Physiology: Need systems of respiration, phonation, resonation, articulation.

C. Disorders of Speech:

1. Misarticulations:

a. Substitutions: th for s thoup for soup.

b. Distortions: slurring s in soup.

c. Omissions: sou for soup.

d. Additions: soupa for soup.

e. Development of speech sounds.

f. Evaluation of speech: Articulation test and oral-peripheral.

g. Therapy: Correct sounds in isolation, syllables, words, connected speech.

2. Dysarthria:

a. Definition: Slurred, thick speech.

b. Etiology: CVA, lack of dentures.

c. Evaluation: Subjective auditory measurement, assessment of the speech musculature.

d. Therapy: Stressing slow speech, exaggerated movement of the speech musculature, self-auditory monitoring.

10 3. Apraxia:

a. Definition: Inability to coordinate the speech movements necessary in producing a word or words.

b. Etiology: Usually CVA or other neurologic problems.

c. Evaluation: Articulation testing.

d. Therapy: Retraining for affected sounds.

4. Stuttering:

a. Definition: Hesitations; prolongations; repetitions of sounds, words, phrases, sentences; secondary behavioral characteristics.

b. Etiology: Largely unknown.

(1) Theories:

(a) Organic.

(b) Delayed auditory feedback.

(c) A learned behavior.

c. Evaluation: Analyze stuttering in depth.

d. Therapy: Self-monitoring, slow speech, reshaping.

II. Language

A. Definition: Expression of ideas - verbally, gesturally, facial expression, body movement, intonation patterns, graphically.

B. Development of language.

C. Disorders of language.

1. Language delay: Behind in the development of receptive and expressive vocabulary.

a. Echolalia: Repeat what is said due to an inability to process incoming information accompanied by a delay in expressive vocabulary.

b. Nonverbal: Very behind in the development of linguistic concepts.

c. Cerebral palsy: Show a delay due to a limited experience, accompanied by speech and hearing difficulties.

11 d. Bilingual/multilingual: Difficult to learn two or more languages at once.

2. Aphasia: Inability to use symbols of language either receptively or expressively - a word retrieval problem.

a. Etiology: Neurologic problem to the speech and language areas of the brain.

b. Evaluation: Of hearing acuity; of receptive and expressive linguistic skills, including verbal, auditory, visual, graphic, and gestural.

c. Therapy: Word retrieval to a funcional linguistic level.

D. Evaluation:

1. Complete audiologic workup.

2. Tests of receptive and expressive language skills and modalities.

3. A comparison to the norm.

4. Outside referral for language-related testing.

E. Therapy: Individualized therapy and home program directed at bringing linguistic skills to as near a normal level as possible.

III. Voice

A. Definition: Sound produced by the vibration of the vocal cords.

1. Optimal pitch for adult male = 125 Hz.

2. Optimal pitch for adult female = 225 Hz.

B. Normal voice: Falls into these frequencies, has clear sounding quality, adequate volume, proper resonance balance.

Abnormal voice calls attention to itself because it significantly deviates from the norm.

C. Abnormal voice:

1. Disorders of intensity:

A. Aphonia: Total lack of voice.

(1) Hysteric: Associated with deep emotional conflict.

(2) Laryngectomy.

12 b. Dysphonia: Partial loss of voice.

(1) Spastic dysphonia: Strain of the voice and hence distorted or unintelligible utterances.

2. Disorders of pitch:

a. High pitch: Due to tension - falsetto.

b. Low pitch: Glottal fry - due to the addition of mass to the folds.

c. Monopitch: Little or no inflection.

d. Pitch breaks: Sudden variations in pitch.

e. Falsetto: High pitch in all speech output.

f. Tremulous voice: Quavering overlay of voice.

g. Glottal fry: Bubbly, crackling sound.

3. Disorders of phonation:

a. Harshness.

b. Breathiness.

c. Hoarseness.

d. Functional origin:

(1) Vocal abuse.

(2) Vocal misuse.

e. Organic origin.

(1) Improper approximation.

(2) Atyipical laryngeal size.

(3) Edema.

(4) Laryngeal growths.

(5) Laryngeal paralysis.

13 4. Disorders of resonance. a. Hypernasality. b. Hyponasality.

D. Evaluation:

1. Complete case history. a. Voice sample taped as a baseline for measurement. b. Detection of vocal abuses and misuses. c. Voice analysis.

E. Therapy for most voice disorders includes:

1. Identification and elimination of vocal abuses.

2. Instruction on obtaining correct resonance balance.

3. Locating optimal pitch.

4. Maintenance of optimal pitch.

5. Respiration training.

6. Relaxation exercises.

F. Therapy for a laryngectomy patient.

1. Introduction and instruction of alternate means of communication (electrolarynx).

2. Family counseling regarding rehabilitative stages of a laryngectomy patient.

3. Training in esophageal voice production.

4. Tracheoesophageal puncture/voice prosthesis.

14 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 7: Infections of the Ear

Common Pathogens Found in Infections of the Ear

Acute Otitis Media

1. Bacterial pathogens isolated from middle ear fluids (MEF) of children with acute otitis media (AOM) are seen in Table 7-1.

Table 7-1. Pathogens Found in the MEF of AOM

Microorganism Children with Pathogen (%)

Streptococcus pneumoniae 35 Haemophilus influenzae 20 Streptococcus, group A 8 Branhamella catarrhalis 3 Staphylococcus aureus 2 Gram-negative enteric bacilli 1 Mixed 2 None or nonpathogens 29

2. Streptococcus pneumoniae and H. influenzae are the most frequently isolated bacteria from middle ear effusion of AOM.

3. The eight most common types of S. pneumoniae in order of decreasing frequency are 19, 3, 6, 23, 14, 18, 4, and 7. All are included in a pneumococcal vaccine (Pneumovax) introduced in the USA in February 1978.

4. Otitis media due to H. influenzae is associated with non-typeable strains in almost all patients. In approximately 10% the otitis is due to type B. Some children infected with H. influenzae type B appear to be very toxic and may have meningitis.

5. Until recently H. influenzae was believed to be limited in importance to preschool age children under 5 years of age, but several studies indicate that this organism is a significant cause of otitis media until the age of 10 years and older. Acute otitis media in children through adolescence should be treated with antibiotics known to be effective against H. influenzae.

6. Gram-negative enteric bacilli are isolated from the MEF of approximately 20% of infants up to 6 weeks of age, but are rarely present in the MEF of older children.

7. Group A beta-hemolytic streptococci and S. aureus are infrequent causes of otitis.

8. Preliminary results suggest that anaerobic bacteria are responsible for some episodes of OM.

1 9. Although epidemiologic data suggest that virus infection is associated with OM, the results of ten studies indicate that these agents are infrequently isolated from MEF of children with OM. Viruses were isolated from 29 of 663 patients (4.4%). Respiratory syncytial viruse and influenza virus were isolated most frequently.

10. The results of seven studies of mycoplasma infection in 771 patients with OM included only one isolation of Mycoplasma pneumoniae from MEF.

11. Staphylococcus sp. and Pseudomonas aeruginosa isolated in acute otitis media probably represented an overgrowth or contamination of the culture by infection of the external auditory canal.

12. Chlamyidia trachomatis is the etiologic agent of a mild, but persistent pneumonia in infants that may be accompanied by otitis media.

13. Recent studies of asymptomatic children with persistent MEF indicate that bacterial pathogens are present in some of these fluids. Investigators in Columbus, Boston, and Pittsburgh obtained MEF for culture at the time of myringotomy or placement of tympanostomy tubes. Bacteria were isolated from MEF of 50% of these children; S. pneumoniae, H. influenzae, or group A streptococci were isolated from 10-20% of the patients. There were only minimal differences in the rates of isolation of bacteria from serous, mucoid, or purulent fluids. The signifance of these results is uncertain, but they suggest that persistent effusion may be a result of asymptomatic but prolonged infection, or may be an immune reponse to a persisting antigen.

14. Acute necrotizing otitis media is a virulent form of acute otitis media, nearly always caused by a beta-hemolytic streptococcus, and seen in children who are acutely ill from a systemic infectious disease such as scarlet fever, measles, pneumonia, or influenza. The pathologic process is true necrosis of the soft tissues and bones of the middle ear and mastoid.

The disease is characterized by a profuse, purulent, foul-smelling otorrhea, a large tympanic membrane perforation (in contrast to a small perforation seen in the usual acute suppurative otitis media), sloughing of the annulus tympanicus, portions of ossicles, the scutum, and the mastoid air cells. Occasionally, naked white bone of the promontory and the antrum may be observed.

15. Acute mastoiditis is most likely caused by S. pneumoniae, but Streptococcus pyogenes and Staphylococcus aureus are almost as frequent pathogens. Surprisingly, mastoiditis is rarely due to H. influenzae, which causes mucous membrane infections, but may be less invasive to bone.

16. Most culture studies utilize tympanocentesis as the method of sampling infected material. However, Schwartz et al showed a high correlation between culture results of tympanocentesis and deep nasopharyngeal samplings (77% for a haemophilus and 84% for pneumococcus) when: (a) the culture was taked deep and vigorously in the nasopharyngeal- adenoidal area, and (b) the material was promptly plated on sheep blood and chocolate agar

2 plates without its being passed through a transport broth (which decreases accuracy by allowing overgrowth of nonpathogens).

17. Indications for myringotomy in AOM include: (a) severe pain, (b) failure of initial antibiotic therapy, (c) an immunologically compromised child, and (d) complicated AOM.

Otitis Media with Effusion (Serous Otitis Media)

Otitis media with effusion (OME) continues to be the leading cause of hearing loss in childhood. Recent studies have shown that more than 30% of all children have had three or more episodes of the disorder by their second birthday.

Synonyms for this condition include secretory otitis, glue ear, chronic catarrh otitis, and nonsuppurative otitis.

1. A careful and precise otoscopic examination with the use of the pneumatic otoscope is essential for correct diagnosis. The use of tuning forks, tympanometry, audiometry, and the operating microscope will aid and confirm the diagosis. Recently the use of brain-stem evoked response audiometry has been proposed to differentiate conductive from sensorineural hearing loss. It appears that there is an increase in the latency of wave I in patients with middle ear effusion.

2. Nonoperative therapy includes the use of (a) antihistamines and decongestants, (b) corticosteroids, (c) antibiotics, (d) autoinflation (Valsalva's maneuver), (e) politzerization and (f) control of etiologic factors (nasal infection, sinusitis, allergy, etc).

3. The use of pressure equalizing (PE) or ventilating tubes has become the most widely accepted therapeutic modality for the treatment of otitis media with effusion. Ever since the reintroduction of this treatment in 1954 by Armstrong, the placement of a PE tube through the tympanic membrane has gained worldwide acceptance and is rapidly becoming the most commonly performed surgical procedure in the United States.

4. Approximately 80% of intubated patients respond after one insertion and require no further therapy. Approximately 20% of the patients with OME will require reinsertion of PE tubes on two or more occasions.

5. The overall complication rate after PE tube intubation is about 11%. These include:

a. Persistent otorrhea (5-15%).

b. Persistent perforation after tube extrusion.

c. Scarring or atrophic membrane formation.

d. Granuloma of TM or EAC.

e. Tympanosclerosis.

3 f. Cholesteatoma (by ingrowth of the surface epithelium).

g. Ossicular disruption.

h. Sensorineural hearing loss.

6. Indications for insertion of PE tubes for OME are:

a. Persistent effusion for more than 12 weeks.

b. Failure to respond to 4-week antibiotic-antihistamine-decongestant therapy.

c. Severe otitis media with considerable atelectasis or retraction pocket.

d. Severe conductive deafness.

e. Impending cholesteatoma.

f. "Otitis media prone" child.

g. Cleft palate.

7. Placement of PE tubes significantly decreased the number of episodes of acute purulent OM and was shown to be an effective method of prophylaxis in the otitis prone child.

Immunoglobulin levels in the middle ear in this group of patients were found to be similar to those levels in patients with otitis media with effusion. This supports the hypothesis that a dynamic relationship between the different clinical entities of otitis media exists.

8. Adenoidectomy with or without tonsillectomy: Advocates for adenoidectomy argue that hypertrophic adenoids produce a mechanical obstruction of the eustachian tube orifice leading to diminished middle ear ventilation. Others believe that the adenoids and occasionally the tonisls may harbor microorganisms that ascend through the eustachian tube, establishing an inflammatory process and a middle ear effusion. Unfortunately the controlled studes necessary to prove or disprove such hypotheses are lacking.

According to recent studies, adenoidectomy had no additional beneficial effect on the cure rate obtained by tympanostomy. Data thus far collected by Paradise et al are not sufficient to reach a conclusion for or against the efficacy of adenoidectomy for otitis media, but it is apparent that adenoidectomy by no means eliminates the problem.

9. The successful use of simple mastoidectomy has been reported by Holmquist et al. In most ears with middle ear effusion the mastoid air cells may be involved as well. The mucosal changes and the secretion extends into all cavities of the ear including the mastoid air cells. In most ears insertion of a ventilating tube through the tympanic membrane is adequate for proper aeration of the middle ear as well as of the mastoid air cell system. In a small percentage of cases, the ear will continue to drain and the mastoid will not clear up.

4 Antibiotics and decongestants fail to cure the ear. In such an event, simple mastoidectomy is indicated. Cholesterol granuloma and/or cholesteatoma may be found.

10. Children with conductive hearing loss due to OME may be at risk for language delays that have been suspected of causing later language problems. After a 3-months duration of serous otitis, a language evaluation should be given the infant or child. Any language delay should be promptly treated with a home language stimulation program and, in more extreme cases, there should be a consideration of hearing aid use.

11. Draf reported that 61% of x-ray controlled patients with OME had a pathologic condition of the paranasal sinuses. In persistent cases of OME, the nose and sinuses should be evaluated.

Chronic Otitis Media

1. The bacterial flora found in chronic otitis media varies considerably. The predominating organisms are usually gram-negative bacilli.

2. Chronic suppurative otitis media with tympanic membrane perforation or cholesteatoma, is usually attributed to the aerobic P. aeruginosa and S. aureus organisms, but proteus sp. and Escherichia coli are also frequently isolated.

Draining ears, especially if cholesteatoma (keratoma) is present, often produce a foul- smelling pus which is characteristic of anaerobic streptococcal infections. From two-thirds of infected cholesteatomas various anaerobes can b recovered. Most chronic ear drainage results from mixed infections with both aerobic and anaerobic pathogens. 13% of anaerobes are Bacteroides fragilis.

3. Tuberculous otitis media is a rare type of infection caused by acid-fast tuberculous bacilli (Mycobacterium tuberculosis), characterized by an insidious and painless onset; scanty thin odorless discharge; progressive enlargement of the perforation in the pars tensa; multiple perforations with pale granulations; and hearing loss out of proportion to other symptoms. It is usually secondary to pulmonary tuberculosis. Early investigators believed that the portal of entry was the eustachian tube, while others felt that the infection was spread by the hematogenous route. Any caseous focus may be a source from which tubercle bacilli enter the bloodstream to reach the temporal bone. Histologically, it is characterized by (a) extensive edema and infiltration of the mucosa and tympanic membrane by round cells and giant cells, (b) formation of numerous tubercles consisting of epithelioid and lymphoid cells and containing characteristic giant cells of the Langerhans type, (c) caseation and ulceration.

Diagnosis may be made from direct smears, cultures, and histologic examination of granulation tissue removed from the middle ear or mastoid. Tuberculosis should be suspected when otitis media does not respond readily to ordinary methods of therapy.

Isoniazid and PAS (para-aminosalicylic acid) are commonly used for initial treatment. Streptomycin may be added in more severe cases.

5 4. Syphilitic otitis media (rare today) is caused by Treponema pallidum. The usual aural manifestations of syphilis is a meningoneurolabyrinthitis, but occasionally the middle ear cleft is involved by a gummatous osteitis or osteoperiosteitis. The gummatous change may lead to a foul discharge and extensive destruction of the mastoid. Secondary pyogenic infection develops. Diagnosis may be suspected from foul painless otorrhea in the presence of sensorineural deafness and confirmed by specific tests for syphilis: (a) detection of T. pallidum by direct darkfield examination of material obtained from a primary and secondary lesion, (b) serologic tests (Wassermann, VDRL, Kahn and Kline, Kolmer, rapid plasma reagin tests). (c) Treponema pallidum immobilization test (TPI), and (d) the more sensitive fluorescent treponemal antibody absorption test (FTA-ABS). Indudectomy may help the diagnosis. Treatment should be both local (removal of sequestra may be necessary) and general (systemic penicillin and steroid therapy). There is some evidence that penicillin alone will not eradicate T. pallidum from the human temporal bone, and that ampicillin may reach higher levels than penicillin in perilymph. However, ampicillin and penicillin, when each is combined with a high dosage of steroids, seem equally effective in the treatment of syphilitic hearing loss.

5. Late congenital syphilis is characterized by the following: A rather abrupt onset of deafness in apparently healthy young adults; bilateral involvement, which initially may be asymmetric; family history of lues; periods of exacerbations, i.e. pregnancy, colds; rapid progression even to complete bilateral loss of cochlear and vestibular function in some cases; vestibular symptoms occasionally resembling those seen in Ménière's disease; Tullio's sign (vertigo and nystagmus on stimulation with loud noise); Hennebert's sign: despite an intact drum, a positive fistula test, especially with negative pressure; preponderance in females; negative or equivocal blood serology (Wassermann, VDRL, Kahn and Kline, Kolmer tests), with negative spinal fluid serology; positive FTA-ABS; and a long interval between eye and ear involvement.

One should remember that some diseases may produce false-positive reactions to serologic tests. These include malaria, infectious mononucleosis, systemic lupus erythematosus, and leprosy. Suphilis, both congenital and acquired, can cause sensorineural hearing loss. The incidence of such loss among various forms of syphilis has been estimated at 18% for late congenital, 17% for early congenital, 25% for late latent, 29% for asymptomatic neurosyphilis, and 80% for symptomatic syphilis.

The histopathology of syphilitic infection is primarily two-fold. First, syphilis may cause a meningoneurolabyrinthitis as the predominant lesion in early (infantile) congenital syphilis and in the acute meningitides of secondary and tertiary syphilis. Second, syphilis may cause an osteitis of the temporal bone as the predominant lesion with secondary involvement of the membranous labyrinth in late (tardive) congenital, late latent, and tertiary syphilis. Pathologically, the lesions of congenital and acquired syphilis cannot be differentiated and similarly the hearing loss may be sudden or progressive, with or without vestibular involvement in both congenital and acquired syphilis.

The basic histologic feature of bone involvement is an inflammatory rarefying osteitis featured by round cell infiltration, multinucleated giant cells, and endarteritis leading to varying degrees of destruction of the bony labyrinth. Mononuclear leukocytic infiltration and obliterative endarteritis are common to all syphilitic lesions, whatever the organ affected. Mild

6 reactions promote proliferation of fibrous tissue leading to an inflammatory fibrosis. Severe reactions result in gummatous lesions which are characterized by lymphocytic infiltration, vascular occlusion, and central necrosis.

Other sites commonly involved in congenital syphilis are (a) the nasal cartilaginous and bony framework (snuffles), (b) periosteitis of the cranial bones (bossing of the skull), (c) periosteitis of the tibia (saber shins), (d) injury to odontogenous tissue (Hutchinson's teeth), (e) involvement of epiphyseal cartilages (reduction in stature), and (f) interstitial keratitis (cloudy cornea).

Otitis Externa

1. The usual infecting organism found in localized external otitis (furunculosis) is S. aureus.

2. The most common organisms found in diffuse external otitis (swimmer's ear) are Pseudomonas aeruginosa (B. pyocyaneus) and Staphylococcus. Less commonly found are Streptococcus and Proteus vulgaris.

3. The most common organism found in perichondritis is P. aeruginosa (B. pyocyaneus).

4. The most common fungi affecting the external ear are Candida albicans, Aspergillus niger, and yeastlike fungi.

5. The most common organism found in impetigo contagiosa of the external ear is S. aureus.

6. Bullous myringitis is caused by a virus and generally associated with an acute upper respiratory infection (most commonly influenza). The Mycoplasma pneumoniae organism was implicated but its role in isolated tympanic membrane infection is not proved. In children the same organisms of acute otitis media may be found in bullous myringitis.

Temporary sensorineural hearing loss may be associated with this condition.

The serous or hemorrhagic blebs on the tympanic membrane and adjacent meatal wall may produce severe pain without fever and hearing loss. Treatment is supportive. The blebs may be opened in the presence of severe pain.

7. Herpes zoster oticum (Ramsay Hunt syndrome) is a viral infection affecting the geniculate ganglion characterized by facial paralysis; herpetic vesicles in the external auditory canal and cavum conchae; severe ear pain; and impairment of lacrimation, salivation, and taste; often with vertigo and a sensorineural hearing loss. Treatment is symptomatic. Facial nerve decompression including the region of the geniculate ganglion may be indicated when electrical excitability is lost or markedly impaired.

8. Malignant external otitis (necrotizing external otitis) is a serious infection of high mortality which occurs in the elderly diabetic. Other predisposing conditions include

7 arteriosclerosis, immunosuppression by chemotherapy, steroid administration, or hypogammaglobulinemia. The responsible organism is uniformly P. aeruginosa.

It begins insidiously, frequently with a history of minor trauma, and is characterized by progressive pain and purulent discharge from the external canal. The infection begins in the external auditory canal and extends inferiorly into the soft tissues at the junction of the cartilaginous and osseous portions of the external auditory canal or through the fissures of Santorini. The infection thus involves the parotid gland, cartilage, bone, nerves, and blood vessels.

The pathognomonic sign is the presence of active granulation tissue in the external auditory canal at the junction of its osseous and cartilaginous portion. There is pain on movement of the temporomandibular joint and marked tenderness on palpation beneath the external auditory canal. Facial palsy is an ominous prognostic sign and is due to involvement of the facial nerve at its exit from the stylomastoid foramen.

The infection is resistant to ordinary methods of treatment and, if not arrested, progresses to chondritis; osteitis and osteomyelitis of the temporal bone and base of the skull; facial nerve paralysis and other multiple cranial nerve palsies; sigmoid sinus thrombosis; meningitis; brain abscess; and death.

Treatment should consist of local debridement and systemic administration of carbenicillin and gentamicin for 4-6 weeks. Wide surgical debridement, including radical mastoidectomy, total parotidectomy, excision of the condyle and ascending ramus of the mandible, and occasionally sacrifice of the facial nerve, may be necessary for its control. Subtotal temporal bone resection to gain access to the primary focus of infection and provide adequate drainage may become necessary.

9. The most widely used otic preparations contain antibiotics such as neomycin and/or polymixin and also a steroid to relieve inflammation. The inclusion of both antibiotics is recommended in treating acute external otitis and chronic suppurative otitis media. Chloramphenicol drops are available to treat B. fragilis infection. Both amphotericin B and nystatin are available in topical preparations to treat candidiasis, but they have no activity against Aspergillus.

Cholesterol Granuloma

The cholesterol granuloma does not represent an independent clinical or pathologic entity. Rather, it is a term used for the description of a tissue response of the temporal bone to the presence of a particular foreign body, i.e. cholesterol crystals.

Three factors are considered to play an important role in its development: interference with drainage, hemorrhage, and obstruction of ventilation. The cause of the initial hemorrhage may be a hemorrhagic inflammation or diathesis, a trauma, or some other form of vascular disorder. Interference with air exchange and clearance can be caused by: tubal blockage, persistent mesenchyme, polypoid changes, scar formations, tympanosclerosis, cholesteatoma, etc.

8 The cholesterol granuloma may develop in any portion of the pneumatic system of the temporal bone, and it can be associated with a variety of middle ear disorders. Its principal precursor is the chronic middle ear effusion or serous otitis media. Its clinical expression and hallmark is the "idiopathic hematotympanum", the dark bluish discoloration of the tympanic membrane.

Osteitis and bone erosion are manifestations of an unusual more advanced stage. Resorption of bone, in a rare instance, may lead to extensive destruction of the temporal bone.

Definition of Tympanoplasty and Mastoidectomy

Definitions

Simple Mastoidectomy (Cortical Mastoidectomy)

A complete mastoidectomy with anatomic disection of all accessible pneumatic cells is indicated for acute mastoiditis with impending or existing complications, or acute mastoiditis which does not resolve after appropriate antibiotic therapy and myringotomy drainage.

Myringoplasty

An operation in which the reconstructive procedure is limited to the repair of tympanic membrane perforation.

Tympanoplasty Without Mastoidectomy

An operation to eradicate disease in the middle ear and to reconstruct the hearing mechanism, without mastoid surgery.

Tympanoplasty With Mastoidectomy

An operation to eradicate disease in both the mastoid process and middle ear cavity, and to reconstruct the hearing mechanism.

Modified Radical Mastoidectomy

An operation to eradicate disease of the epitympanum and mastoid in which the mastoid and epitympanic spaces are converted into an easily accessible common cavity by removal of the posterior and superior external bony canal walls. In this operation the tympanic membrane and functioning ossicles are left intact. Thus infection is eradicated and hearing preserved.

Radical Mastoidectomy

An operation to eradicate disease of the middle ear and mastoid in which the mastoid, antrum, and the middle ear are exteriorized so that they form a common cavity with the

9 external auditory canal. In this operation, the tympanic membrane, malleus, incus, chorda tympani, and the mucoperiosteal lining are all removed.

Classifications of Tympanoplasty by Wullstein (Table 7-2)

Table 7-2. Classification of Tympanoplasty by Wullstein

Type --> Damage to Middle Ear - Method of Repair

I --> Perforated tympanic membrane with normal ossicular chain. - Closure of perforation, type I same as myringoplasty.

II --> Perforation of tympanic membrane with erosion of malleus. - Closure with graft against incus or remains of malleus.

III --> Destruction of tympanic membrane and ossicular chain but with intact and mobile stapes. - Graft contacts normal stapes. Also gives sound protection for round window.

IV --> Similar to type III, but head, neck, and crura of stapes missing; footplate mobile. - Mobile footplate left exposed or graft attaches to mobile footplate; air pocket between round window and graft provides sound protection for round window.

V --> Similar to type IV plus fixed footplate. - Fenestra in horizontal semicircular canal; graft seals off middle ear to give sound protection for round window.

Mastoid Obliteration Operation

An operation to eradicate disease when present and to obliterate mastoid or fenestration cavities.

Paparella modified type V tympanoplasty, subdividing it into type Va (fenestration of the horizontal semicircular canal) and type Vb (stapedectomy in cases of tympanoplasty type IV with stapes fixation) (Fig. 7-1).

Classification of Tympanoplasty by Farrior

Farrior proposed the types of tympanoplasties according to the basic pathologic anatomy at the completion of surgery, rather than classifying them according to the method of reconstruction. He also advocated the grouping of cases according to the preoperative status

10 of the middle ear mucosa, eustachian tube function, and associated diseases of the nose and nasopharynx.

Classification

1. Type I: The reconstruction of a new eardrum, intact malleus, incus and stapes.

2. Type II: The reconstruction of a new eardrum in its natural position.

3. Type III: The reconstruction of a new eardrum on top of an upright, freely mobile stapes.

4. Type IV: The reconstruction of a new eardrum and columella on the stapedial footplate.

5. Type V: The reconstruction of an eardrum either over a fistula in the horizontal semicircular canal or a new eardrum with a secondary fenestration of the horizontal semicircular canal.

Tympanoplasty III (Farrior)

1. Type III: drum on stapes.

2. Type III IG: incus graft.

3. Type III IGM: incus graft to malleus.

4. Type III MR: malleus repositioned.

5. Type III MG: malleus graft.

6. Type III BG: bone graft.

7. Type III SS MS: stainless steel malleus to stapes, etc.

The best results in tympanoplasty are obtained when the stapes is upright and freely movable, regardless of the type of reconstruction used. In classifying tympanoplasty according to basic pathologic anatomy all cases with intact stapedial superstructures are classified under type III with indication of the type of superstructure by initials, as IG incus graft.

Tympanoplasty IV (Farrior)

1. Type IV: no columella.

2. Type IV IG: incus graft.

3. Type IV MG: malleus graft.

11 4. Type IV BG: bone graft.

5. Type IV C SS: cartilage graft with stainless steel.

6. Type IV HG MIS: homograft drum with malleus, incus, and stapes.

In classifying tympanoplasty according to the basic pathologic anatomy all casres with absent stapedial superstructures are subclassified under type IV with indication of the type of superstructure reconstructed as MG (malleus graft).

Grouping (Bellucci)

1. Group I: A good prognosis being those cases who are relatively free of any associated middle ear or eustachian tube disease.

2. Group II: A fair prognosis, has a period of quiescence.

3. Group III: With a poor prognosis, has no period of quiescence.

4. Group IV: With a very poor prognosis, has persistent disease with associated deformity of the nasopharynx as cleft palate.

Systematic Approach to Evaluate and Treat Chronic Otitis Media

Systematic preoperative evaluation of patients with chronic otitis media and a brief description of surgical procedures commonly performed for chronic otitis media will be described.

Preoperative Evaluation

Preoperative evaluation should include:

1. Careful analysis of symptoms and signs.

2. Otologic examination.

3. Examination of the upper respiratory tract.

4. Audiologic evaluation.

5. Preoperative preparation.

Careful Analysis of Symptoms and Signs

Careful analysis of the symptoms and findings allows the otologist to determine the need for surgery, its urgency (if any), and the anticipated results.

12 Otorrhea

1. Discharge from the ear is the most common manifestation of chronic otitis media. Note should be made of its duration, frequency, character, and odor.

2. Malodorous discharge, at times bloody, of a constant or frequently recurring nature usually indicates significant middle ear and mastoid disease.

3. A central perforation without significant disease is usually accompanied by episodes of mucoid discharge of short duration. This discharge may be initiated by an upper respiratory infection or by introduction of water into the ear.

Hearing Loss

1. The extent of hearing impairment in chronic otitis media is dependent primarily on the degree of ossicular disruption.

2. In the absence of cholesteatoma, a conductive loss of 20 dB or less usually indicates that the ossicular chain is intact.

3. Disruption or fixation of the chain results in an impairment of 30 dB or more.

4. It is not unusual to find normal hearing in an ear with an attic perforation and cholesteatoma. This may be an indication of an intact ossicular chain. However, this may indicate that sound transmission is accomplished through a mass of cholesteatoma that has replaced ossicular tissue ("cholesteatoma hearer" or "silent cholesteatoma").

5. A progressive conductive impairment in the absence of active disease suggests ossicular fixation. This may be due to tympanosclerosis or otosclerosis. This is significant because surgery may have to be performed in two stages: one a graft of the tympanic membrane to eliminate disease, the other a revision to perform stapedectomy or type Vb tympanoplasty. The patient should be advised of this possibility preoperatively.

Pain (Otalgia)

1. Pain is not a frequent complaint in chronic otitis media unless there is secondary otitis externa.

2. Dull pain, in the absence of otitis externa, particularly when it is severe enough to disturb sleep, is usually an indication of an expanding mass of cholesteatoma or empyema in the antrum. Surgery should not be delayed.

3. Pain may indicate acute exacerbation of infection by upper respiratory infection.

4. Pain may indicate development of complications of chronic otitis media such as petrositis, subperiosteal abscess, or lateral sinus thrombosis.

13 Vertigo

1. Minor degrees of postural vertigo are seen frequently in patients with chronic otitis media.

2. Continuous vertigo or postural vertigo of recent onset in a patient with cholesteatoma is usually an indication for immediate surgery. It indicates labyrinthine irritation or a semicircular canal fistula.

Facial Nerve Paralysis

Facial nerve paralysis occasionally develops in the course of chronic otitis media with cholesteatoma. If and when it occurs, surgery should be undertaken without delay to relieve pressure on the nerve. It is not necessary to "decompress" the nerve in most cases. Elimination of the disease is sufficient.

Examination of the Upper Respiratory Tract

1. A sound review of the history and careful examination of the upper respiratory tract is mandatory.

2. Gross abnormalities and chronic suppurative sinus disease should be identified and corrected before reconstructive surgery is performed.

3. Patients with histories of "repeated colds" in winter months are not good candidates for tympanoplasty.

Otologic Examination

1. Careful inspection of the ear should be the first part of the systematic evaluation. The inspection should include examination under magnification, with an otoscope or preferably with a surgical microscope.

2. Pneumatic otoscopy should be routine to examine the mobility of the tympanic membrane and malleus and to rule out coexisting chronic serous otits media. Care must be taken to avoid forceful insufflation. Lethal intracranial complications following air insufflation have been reported.

3. Careful examination of the attic area should be done to identify hidden retraction pockets, perforation, and/or cholesteatoma. It is often necessary to freely change the position of the patient's head and the angulation of the otoscope or microscope.

4. The fistula test should be performed whenever a marginal perforation is present or when there is a history of dizziness.

5. Specific notes should be made regarding the type of perforation, the character of the discharge, the status of the mucosa, and the presence or absence of ossicular tissue.

14 Discharge (Otorrhea)

1. The character of the discharge, whether mucoid or purulent, with or without odor, is noted.

2. A mucoid discharge without odor is usually an indication of mucosal disease and/or eustachian tube malfunction, often of a temporary nature.

3. Purulent discharge is an indication of infection. This may be a transient mucous membrane infection by opportunistic organisms, in which case it should clear rapidly with local treatment. Purulent discharge that does not subside on local treatment is an indication of a resistant organism, irreversible mucous membrane disease, cholesteatoma, or all of these.

4. The presence of odor suggests tissue necrosis. A malodorous discharge usually is found in active cholesteatoma.

Perforation

1. Perforations of the tympanic membrane are generally divided into two types: central and marginal.

2. A central perforation usually is not associated with cholesteatoma although there are exceptions, especially in children. Intermittent discharge of mucoid material, responding quickly to local treatment, is the rule.

3. A marginal perforation usually is associated with a cholesteatoma. Continuous or frequently recurring malodorous discharge is the rule. This may respond only temporarily, if at all, to local treatment.

4. There are two types of marginal perforations: attic and posterosuperior marginal. Attic perforations involve the area of the pars flaccida. The pars tensa may at times appear quite normal. As a result, perforations in this area occasionally are overlooked. A small perforation may be covered by dried crusts. A polyp of granulation tissue may be seen to extrude through the perforation and tends to block discharge. The hearing impairment is negligible at times because the cholesteatoma develops external to the ossicles and even may extend into the antrum without producing significant ossicular necrosis.

5. A posterosuperior marginal perforation below the malleolar ligament may or may not be associated with cholesteatoma. When cholesteatoma is present, the hearing impairment tends to be more severe than with attic perforation. The incus, and at times the stapes, is destroyed early in the development of the disease.

Status of the Middle Ear Mucosa

1. Much may be learned regarding the possible outcome of surgery by careful evaluation of the middle ear as seen through the perforation.

15 2. The character of the mucosa, the status of the ossicles, and the presence or absence of tympanosclerosis are noted.

3. The presence of normal or near normal mucous membrane is a favorable prognostic sign. When squamous epithelium is observed in the middle ear, the status of the tubotympanic recess should be checked.

4. When ossicular necrosis occurs, usually the incus is the first involved. Of prime importance is the status of the stapes. When the stapes superstructure is absent the prognosis for restoration of hearing is usually less favorable. If the malleus handle is also absent, a two- stage operation may be required for hearing improvement.

5. Tympanosclerosis is the term used to describe a sclerotic or hyaline change of the submucosal tissue of the middle ear. It appears to be an end product of recurrent acute or chronic ear infection. Hyalinized connective tissue develops under the mucous membrane superficial to the bone. Calcification and ossification may occur. Its presence may affect the ultimate prognosis for hearing improvement. If there is a progressive hearing impairment, there may be ossicular fixation by tympanosclerosis. A second operation for stapedectomy may be required at times: the patient should be informed of this possibility.

Myringosclerosis (Doyle) is the term applied to describe deposits of hyaline masses with fibrous layer of the tympanic membrane, but it also is referred generally to as tympanosclerosis of the tympanic membrane. It is often necessary to remove these hyaline masses for a successful myringoplasty.

Fistula Test

This is a production of vertigo and deviation of the eyes on the application of pressure to the affected ear. This is elicited by increasing the pressure within the ear canal by means of a pneumatic otoscope or Politzer's bag with an olive tip, or pressing sharply on the tragus with the thumb. Suction with the Politzer bag may cause the reversal of the labyrinthine symptoms. The significance of this test is that there is a fistula of the labyrinth due to destructive cholesteatoma or infection. A positive fistula test is present in two-thirds of the cases with a labyrinthine fistula.

A positive fistula test despite an intact tympanic membrane may indicate an abnormally mobile footplate of the stapes, and suggests congenital syphilis (Hennebert's sign).

Patch Test

When some hearing loss accompanies a central perforation, it is possible to assess the damage of the ossicular chain by placing a small patch of cigarette paper or a Teflon sheet over the perforation. Should the hearing improve with this maneuver, it is assumed that the ossicular chain is intact, and that myringoplasty is likely to succeed in improving the hearing.

16 Eustachian Tube Function

1. The function of the eustachian tube is to protect, aerate, and drain the middle ear and mastoid. The muscle responsible for the opening of the eustachian tube is a part of the tensor veli palatini known as the dilator tubae.

2. Methods of estimating the pressure required to open the eustachian tube have been devised. Unfortunately, the methods of testing the eustachian tube are not entirely satisfactory and it may be difficult to derive a quantitative measurement in a clinical situation.

3. Miller developed a method of eustachian tube function test by applying the pressure differential through a catheter sealed in the external auditory canal. The effect of swallowing on this pressure may be recorded easily on a paper writer such as an ECG machine. The necessity of a perforated tympanic membrane has made the determination of normal values difficult, but this is not a problem in clinical practice since most surgical patients have a preexisting perforation. The application of this method in patients with secretory otitis media requires placing a tube through the intact membrane. In practice the test is carried out by

causing a negative pressure of 250 mmH2O within the external auditory canal and observing the equalization of pressure as the patient swallows. With normal function, the pressure difference is eliminated after several swallows. Four gradations of abnormality have been described, the most severe being in those patients in whom no airflow occurs even with the

application of a positive pressure of 250 mmH2O, indicating complete functional obstruction of the tube.

4. The tympanic cavity clearance test with use of a dye through the intact tympanic membrane or through the tympanic perforation also has been used as a measure of function.

5. Inflation (Valsalva), although not always accurate, remains thesimplest and a most satisfactory method. For practical purposes, if the eustachian tube can be inflated easily by the Valsalva's or Politzer's method the prognosis for successful tympanoplasty is excellent. If inflation is difficult, requiring repeated attempts or use of the catheter, there may be development of secretory otitis after tympanoplasty, requiring insertion of a polyethylene tube through the tympanic membrane.

6. Tympanometry has become a useful method of eustachian tube function test (see Tympanometry below). A blocked eustachian tube is usually associated with type B or C tympanogram.

Audiologic Evaluation

Careful audiometric tests should be performed routinely. The findings are confirmed by the otologist using the tuning fork with a Barany noisemaker to mask the opposite ear.

The minimum audiometric test requirements are pure tone, bone-air conduction thresholds, speech reception levels, and speech discrimination scores. The audiometric test results should always coincide with those of the tuning fork test.

17 Tympanometry

The most significant advance in the identification of middle ear disease is the use of a new instrument. The electroacustic impedance bridge with which a tympanogram can be obtained.

Tympanometry is a reliable, simple procedure, easily carried out in a short time. To perform tympanometry, a small probe is inserted in the external auditory canal. A tone of fixed characteristics is presented via the probe, and the compliance of the tympanic membrane is measured electronically while the external canal pressure is artificially varied.

As is true for eardrum mobility observed visually with a pneumatic otoscope, acoustic compliance is greatest when pressures are equal on both sides of the tympanic membrane. Thus a peak is present when the middle ear pressure is normal (type A). A peak is present in the negative range when middle ear pressure is reduced (type C). Middle ear effusions are present in most cases in which no impedance peak can be determined (type B) (see Fig. 7-2).

For evaluation of chronic otitis media, tympanometry is useful to detect or confirm the following:

1. Otitis media: type B (43%) or C (47%).

2. Cholesteatoma: type B (54%) or C (42%).

3. Middle ear fluid: type B (44%) or C (45%).

4. Scarred or thickened TM: type A (45%) or C (40%).

5. Ossicular fixation: "shallow" type A (reduced peak).

6. Ossicular discontinuity: "deep" type A (100%) (open high peak) (high compliance).

Tympanometry also is useful (1) as an aid in diagnosis when otoscopy is equivocal or difficult, particularly in children, (2) in conforming otoscopic diagnosis, and (3) as a screening test of ear diseases.

Radiographic Examination

Mastoid x-rays which are useful for evaluation of chronic otitis media include Law, Schüller, Stenvers, and submentovertical. Polytomography and/or CT scan may clearly demonstrate bony destruction by cholesteatoma, presence or absence of ossicles, and, in some cases, fistula of the horizontal semicircular canal (see Chap 24).

The decision whether or not to operate is rarely based on the x-ray findings alone. They are helpful, however, in detecting disease not otherwise suspected but which requires mastoid investigation. Occasionally one detects an anatomic variation, i.e. a far forward lateral sinus, which allows a better planned approach to the mastoid disease.

18 Preoperative Treatment

Systemic antibiotics are of minimal value in chronic otitis media. Before any drugs are applied to the ear, the ear should be thoroughly cleared of debris and discharge. This can be done in several different ways. Whenever possible, suction should be employed. The ear can be gently cleaned with cotton applicators. Insufflation of boric acid powder may assist in drying the ear. If fungal infection is suspected, an antifungal agent should be used, usually in powder form.

In patients with chronic otitis media with mucoid discharge treatment of coexisting upper respiratory infections must always be a part of the management of otitis media. Exacerbations of the chronic otitis media commonly accompany and are dependent upon infections in the nose and nasopharynx. Therefore, any conditions such as sinusitis, nasal obstruction, or any other recurrent nasal infection, must be treated before reconstructive surgery is attempted. This also includes allergic evaluation when indicated.

Surgical Treatment

Any patient with a perforated tympanic membrane, chronic ear infection, or a defect in the ossicular chain is a potential candidate for surgical treatment. The primary purpose of surgery may be one or all of the following:

1. Elimination of infection.

2. Improvement of hearing.

3. Closure of a perforation (prevention of infection).

It should be understood first that the complete eradication of disease is a prerequisite of all surgical treatment, and preservation and restoration of hearing are secondary.

Indications for immediate surgery include:

1. Persistent ear pain.

2. Vertigo (continuous).

3. Facial paralysis.

4. Threatened intracranial complications.

The following are the common operations performed in chronic ear surgery. With rare exceptions, an operation for chronic ear disease can be classified as one of the following. Technical surgical variations peculiar to one or another surgeon do not alter the fundamental classifications (Standard Classification for Surgery of Chronic Ear Infection).

19 1. Modified radical mastoidectomy.

2. Radical mastoidectomy.

3. Mastoid obliteration operation.

4. Myringoplasty.

5. Tympanoplasty without mastoidectomy.

6. Tympanoplasty with mastoidectomy.

Modified Radical Mastoidectomy

This commonly performed operation (Bondy's operation) remains the basic operation in most mastoidectomies and tympanoplasties, particularly in the sclerotic mastoid, when the disease extends medial to the facial nerve and into the posterior tympanic recesses. This frequently is used for acquired cholesteatoma and exteriorizes the mastoid antrum to form a common cavity with the external auditory canal. Unlike the radical mastoidectomy the tympanic membrane and functioning ossicles are left intact.

Radical Mastoidectomy

This operation is performed for cases of chronic otitis media with cholesteatoma which have developed secondary to the marginal tympanic perforation; for those beyond the scope of the modified radical mastoidectomy; for chronic otitis media with extension into the labyrinth or petrous portion of the temporal bone; for chronic otitis media with osteitis or osteomyelitis; and for certain neoplasms.

In this operation, the mastoid antrum, mastoid air cells, and middle ear space are exteriorized so that they form a common cavity with the external auditory canal. Meatoplasty is always performed. This permits inspection and periodic cleaning in the postoperative period.,

Radical mastoidectomy is primarily for eradication of infection and not intended to restore the hearing.

Mastoid Obliteration Operation

This is an operation to obliterate the mastoidectomy cavity, which is created following the radical or modified radical mastoidectomy, using a muscle or other tissue pedicle graft. The purpose of this operation is to restore near normal anatomic contour and avoid the frequent aftercare of the mastoid cavity.

When the disease, either cholesteatomatous or necrotic, has extensive ramifications, and there is the slightest doubt in the surgeon's mind regarding complete removal, obliteration of the cavity is not advisable. Recurrent cholesteatoma behind the muscle may develop.

20 Myringoplasty (Type I Tympanoplasty)

Myringoplasty is an operation in which the reconstructive procedure is limited to the repair of tympanic perforation, utilizing a tissue graft. The ossicular chain is intact and mobile.

Since Zollner and Wullstein opened the way to tympanoplasty, there have been many grafting materials used. These include pedicled canal skin (Sooy), canal skin (House and Sheehy), vein (Tabb, Shea), fascia (Storrs), fat (Ringenberg), perichondrium (Goodhill), heart valves, corneas, Gelfoam and more recently, homograft tympanic membranes have been used (Chalat, Marquet, Perkins). Temporalis fascia has become the most widely used of all the grafting materials.

If there has been any discharge from the ear or any moisture in the ear during the previous 6 months, myringoplasty alone is contraindicated. If there has been recent discharge, the repair should be combined with inspection of the attic, aditus and antrum.

An edema or polyposis of the mucous membrane of the middle ear will render the operation unlikely to succeed. Poor eustachian tube function is also a contraindication.

Tympanoplasty Without Mastoidectomy

This refers to an operation to eradicate disease in the middle ear and to reconstruct the hearing mechanism without mastoidectomy, with or without tympanic grafting.

The cardinal principles of tympanoplasty have been and still are: first, control of infection through eradication of disease, and second, reconstruction of the middle ear sound- conducting mechanism.

Type I Tympanoplasty

This was previously discussed. Tympanoplasty type I or myringoplasty is an operation in which the procedure is limited to repair of the tympanic membrane perforation.

It is a good habit to routinely evaluate the middle ear and ossicles to rule out ossicular fixation or discontinuity. This can be done by elevating the tympanomeatal flat. It is important to prepare the graft recipient site first since it is difficult to denude the drumhead after it becomes flaccid. A wide recipient site should be established. In the presence of a total tympanic perforation, this necessitates reflecting the graft up onto the adjacent denuded bony canal wall for at least several millimeters. It is especially important to position the graft "tightly" in the anterior sulcus where graft failure occurs most commonly as a result of technical error. It is here that the branches of the anterior tympanic and deep auricular arteries provide critical blood supply to the graft.

The graft may be placed on the denuded outer surface (overlay graft) or on the denuded inner surface (underlay graft) of the eardrum. In the latter case, the graft is supported by Gelfoam in the middle ear.

21 One of the persistent problems encountered with lateral placement of the graft is lateral migration of the graft away from the handle of the malleus or the anterior sulcus causing a thick blunting or rounding off in this area. Medial placement of the graft avoids this problem. However, when the perforation is total or involves the anterior half of the tympanic membrane, one should be aware that the anterior portion of the medially displaced graft may have a tendency to be pulled away from the drum remnant toward the medial wall of the middle ear and may result in postoperative perforation in this area.

Type II Tympanoplasty

Type II tympanoplasty consists of a graft placement directly upon the incus. This can result from a destroyed malleus but more commonly it is seen in instances in which wide atticoantrotomy or removal of the posterior bony canal wall with mastoidectomy is done, in which case the graft necessarily rests upon the body of the incus.

Type III and Type IV Tympanoplasty

Type III and type IV tympanoplasty are more often done in association with complete mastoidectomy. It is important to expose the facial recess (suprapyramidal recess) and sinus tympani (infrapyramidal recess for the removal of the disease.

Type V Tympanoplasty

While performing tympanoplasty fixation of the stapes due to either otosclerosis or more commonly to tympanosclerosis may be found.

When tympanosclerosis fixation is found it is best to effect a mobilization by removal of the tympanosclerotic tissue, if possible. If this is not possible, all infected tissues should be removed, a graft applied, and the observed for at least 6 months to a year.

Assuming a dry ear with no tendency toward infection, good tubal function, and good auditory function in the opposite ear, type V tympanoplasty can be considered.

The original type V tympanoplasty consisted of fenestration of the horizontal semicircular canal (type Va). If anatomic characteristics are suitable, stapedectomy can be perfomed (type Vb). Surprisingly good hearing may be obtained.

Stapes mobilization or stapedectomy at the time of tympanic membrane grafting, even in the dry ear, may result in a sensorineural hearing loss. At least 12 months should elapse between the initial tympanoplasty and secondary stapedectomy.

Tympanoplasty with Mastoidectomy

The elimination of infection by mastoidectomy is combined with reconstruction of the hearing mechanism.

22 Intact Posterior Wall Mastoidectomy with Tympanoplasty

The intact canal wall technique has been popularized in recent years by many otologists. This procedure prevents a mastoid cavity postoperatively. It should be stressed, however, that the primary objective should always be the removal of the disease and not the preservation of the posterior canal wall.

Following a complete mastoidectomy, the antrum and aditus are enlarged so that the incus is readily seen. The epitympanum is inspected through the aditus. The facial recess (suprapyramidal recess) and sinus tympani (infrapyramidal recess) are exposed and are cleared of disease and tympanoplasty is accomplished. If a large area of the posterior superior canal wall is removed, retraction of the tympanic membrane may develop. A silicone rubber sheet is placed to prevent adhesions. This procedure is contraindicated in the following situations.

1. The only hearing ear.

2. Labyrinthine fistula when the other ear has cholesteatoma.

3. Inadequate exposure due to a severely contracted mastoid.

4. Extensive canal wall destruction by disease.

In these situations, it is "safer" to remove the posterior bony canal, and perform modified radical mastoidectomy combined with tympanoplasty.

Ossicular Reconstruction in Tympanoplasty

1. The goal of functional reconstruction is to obtain a permanent restoration of hearing with neither conductive not sensorineural hearing loss.

2. When the stapes is normal, a carefully fitted ossicular prosthesis (autograft or homograft) is the procedure of choice. The incus is the most readily available ossicle. The incus (shaped or sculptured) may be placed between the handle of the malleus and the head of the stapes, or it may be placed adjacent to the manubrium. When the stapes capitulum is more deeply seated, the malleus head may be used instead of the incus.

More recently, partial ossicular replacement prosthesis (PORP) (Shea) has been successfully used when the incus is missing while the stapes is intact.

3. The most common ossicular problem encountered is necrosis of the long crus of the incus.

4. The most common cause of failure is separation of the ossicle from the head of the stapes, followed by fixation of the ossicle to adjacent bony structures. Extrusion of the repositioned ossicle is uncommon.

5. When the suprastructure of the stapes is missing, a shaped incus may be placed between the handle of the malleus and the mobile footplate, or it may be placed adjacent to

23 the manubrium of the malleus. A strut of cartilage may be used instead. Cartilage has advantages. It does not become fixed by bone and it rarely extrudes.

6. When the malleus handle is absent, there is nothing to stabilize the graft. A two- stage procedure may be necessary: at the first stage, disease is removed, a Silastic sheet inserted to prevent adhesion, and a graft applied. The second stage involves removal of the plastic and insertion of a suitable prosthesis (cartilage). One may use a homograft tympanic membrane en bloc ossicles as a single procedure.

7. The plastipore total ossicular reconstruction prosthesis (TORP) as introduced by Shea is simple to insert, flexible enough for many situations, and suitable for bridging the gap when the incus and the suprastructure of the stapes are missing. To prevent the extrusion of a TORP, or PORP, placement of a piece of cartilage between the prosthesis and the undersurface of the malleus handle or the eardrum has been suggested.

8. The most common cause of ossicular fixation in case of chronic otitis media is tympanosclerosis. It may fix the malleus head and the stapes. When the malleus head is fixed, it should be amputated and the incus repositioned. When the stapes is fixed, disease is removed and the tympanic membrane repaired. At the second operation, a stapedectomy is performed.

9. Plastic and wire prostheses tend to be extruded. Bone chips tend to resorb in time.

10. Tympanoplasty can be successfully accomplished for atelectatic ears in selected cases. Paparella and Jung proposed a method of tympanoplasty which consists of reestablishing the mesotympanic space, strengthening the tympanic membrane by an underplant fascial graft, cutting the tensor tympani, extirpation of any disease, reestablishment of ossicular mobility and continuity, and the insertion of a ventilation tube in the anterior drumhead remnant along with silicone rubber sheeting and a moist Gelfilm implant.

Otologic Homografts

1. Homograft ossicles, mostly obtained from patients when the ossicle must be removed for various reasons, are autoclaved and then stored in 70% alcohol. These ossicles may be used interchangeably with autografts in any situation in which ossicular repositioning is indicated. They are well tolerated and it is difficult to tell microscopically a repositioned incus from a homograft incus.

2. The most frequently used homograft ossicle is homograft incus, followed by malleus and stapes. Smith employs a stapes homograft when there is a loss of the stapedial arch and there is a mobile footplate.

3. Homograft septal and tragal cartilage maintains its shape and structure with the exception of the chondrocytes which are missing from the lacunae. It is well tolerated and becomes covered with mucosa.

4. Homograft tympanic membranes are now available through the ear bank of Project Hear, Palo Alto, Ca. It was first used by Chalat, then Marquet, later by Brandow, and Perkins.

24 5. Tympanic membrane ossicles en bloc homografts may be indicated in the following situations (Perkins):

a. Large tympanic membrane perforations with malleus manubrial disease (malleus fixed, retracted, defective, or absent).

b. Large tympanic membrane perforations with malleus head and incus disease (attic cholesteatoma).

c. Tympanomastoid reconstruction (radical mastoidectomy cavity).

6. Many techniques to reconstruct the radical mastoidectomy cavity have been proposed. They include:

a. Obliteration procedures with soft tissues (musculoplasty) - soft tissues atrophy but cavity filled with dense fibrous tissues.

b. Obliteration with bone (Shea, M.C.).

c. Cartilage reconstruction of the ear canal either with tragal or homograft knee cartilage.

d. Intact posterior canal bone homograft with a homograft tympanic membrane.

e. Reconstruction with a homograft dura form and autogenous bone plate (Perkins 1976) using a homograft tympanic membrane with ossicles en bloc for middle ear reconstruction.

7. Complications of otologic homografts are absorption, infection, fibrous hyperplasia, extrusion, and rejection. They should not be used in an infected cavity.

Complications of Suppurative Otitis Media

Factors That Influence the Development of Complications

1. Factors influencing the spread of infection beyond the middle ear space include: The type and virulence of the infecting organism, its susceptibility to available antibacterial medication, the adequacy of treatment, the resistance of the host, and the presence or absence of associated chronic systemic illness.

2. The type III pneumococcus has a particular predilection for intracranial extension. The resistance of the host to this organism especially is lowered in infancy, old age, and diabetes. Intracranial extension of an acute infection of the middle ear occurs more often in poorly pneumatized than in well pneumatized temporal bones and in ears with a previous history of recurrent otitis media.

25 3. The bone-invading types of chronic otitis media that lead to complications are the relatively uncommon chronic osteomyelitis of the temporal bone, and the much more common cholesteatoma of either the attic retraction or secondary acquired variety.

4. Complications often result from an insufficient dosage or an insufficient period of administration of the drug or selection of a less effective drug without the benefit of culture and sensitivity tests.

5. Cholesteatoma is potentially dangerous because of its capacity to destroy bone. This allows spread of the infection beyond the middle ear and the pneumatized areas of the temporal bone, and may result in otologic or intracranial complications. As it expands and spreads beyond its origin cholesteatoma can impede sound conduction and prevent the natural self-cleaning mechanisms of the ear from functioning.

6. Bone destruction by cholesteatoma results from pyogenic osteitis and enzymatic bone resorption.

7. The matrix of a cholesteatoma consists of the keratinizing squamous epithelium and the subepithelial stroma.

8. The proteolytic enzymes of the cholesteatoma are located primarily at the interface of the epithelium and subepithelium. The squamous epithelium has enzymatic activity as does the superficial layer of the subepithelium. Both together, however, have three times the enzymatic activity of either. The keratinous debris has no enzymatic activity.

9. A cholesteatoma is more destructive of bone when the non-inflamed subepithelium is thin. The bone appears to be protected, somewhat, by thicker subepithelium as long as that epithelium is noninflamed. If the subepithelium is infected and composed of granulation tissue, as in an "active" cholesteatoma, the bone destructive enzymatic activity is enhanced. Similar proteolytic enzymatic activity has been found, to a lesser degree, in normal skin and in chronically infected ears without cholesteatoma.

Pathways of Spread of Infection

Extension of Osteothrombophlebitis

Infection may pass along the vascular channels through intact bone by the process of osteothrombophlebitis. Complications from this pathway usually occur within 10 days of the original infection.

Extension by Bone Erosion

This is the most frequent manner of spread leading to a complication in case of acute otitis in a well pneumatized temporal bone, and it is nearly always the manner of spread in cases of chronic suppurative otitis media.

Complications resulting from this spread of infection usually do not occur for several weeks.

26 In acute otitis media the bone erosion is the result of a coalescent mastoiditis. In chronic otitis media the bone erosion usually is due to a cholesteatoma, less often to chronic osteomyelitis. Through bone erosion, infection can spread to the mastoid cortex, the petrous portion of the temporal bone, the facial nerve, the labyrinth, the lateral sinus, or the dura. The treatment of a complication by bone erosion is directed toward the complication and always includes surgical removal of the focus of suppuration in the temporal bone.

Extension by Preformed Pathways

The preformed pathway may be a normal opening in the bony wall such the oval or round window leading from the middle ear to the labyrinth or the internal auditory meatus, perilymphatic duct, or endolymphatic duct and sac leading from the labyrinth to the meninges. The pathway may be developmental dehiscence of the floor of the hypotympanum or it may be the result of a skull fracture or previous ear surgery such as a fenestration, a stapedectomy, a labyrinthotomy for Ménière's disease, or a mastoidectomy in which dura was exposed. A perilymph fistula following partial or total stapedectomy establishes an open pathway for infection to extend into the labyrinth.

Acute infection often spread through a preformed pathway, causing early complications. Extension in chronic ear infection usually is secondary to bone erosion, causing late complications.

Types of Complications

There are two major categories of complications: extracranial and intracranial. Complications can usefully be classified as follows:

Extracranial

1. Subperiosteal abscess. 2. Facial paralysis. 3. Labyrinthitis. 4. Petrositis.

Intracranial

1. Extradural abscess. 2. Subdural abscess. 3. Brain abscess. 4. Lateral sinus thrombosis. 5. Meningitis. 6. Otitic hydrocephalus.

Subperiosteal Abscess

1. Postauricular abscess (the most common type) is formed by pus spreading through the minute vascular channels in the suprameatal (Macewen's) triangle and presents as a

27 swelling between the tip of the mastoid adn Macewen's triangle. The auricle is displaced forward, outward, and downward.

2. Zygomatic abscess is formed by pus escaping from the zygomatic cells near the squama. This presents as a swelling above and in front of the ear and may be confused with a parotid swelling. Rarely, the pus may spread downward and forward into the mandibular fossa with a displacement of the mandible toward the normal side so that the teeth no longer meet in occlusion.

3. Bezold's abscess results from the perforation of the tip of the inner aspect of the mastoid by the pus which will track down the sternocleidomastoid muscle and present as a swelling in the posterior triangle of the neck.

4. Sagging of the posterior meatal wall by a subperiosteal abscess rarely may occur as a result of a coalescent mastoiditis. Today, this is much less likely to occur in an acute otitis media than in a chronic otitis media with cholesteatoma formation.

5. Parapharyngeal or retropharyngeal abscess may result from an acute suppurative otitis media or mastoiditis. The pus may track from peritubal cells or by formation of an abscess below the petrous pyramid.

6. Treatment of postauricular, zygomatic, and Bezold's abscess is simple mastoidectomy, although a Bezold's abscess may require separate additional incision and drainage.

Facial Paralysis

Direct extension of infection into the facial canal through a dehiscence in the bony covering of the tympanic portion of the nerve or by destruction of the bone overlying the nerve causes facial nerve paralysis.

Immediate surgical decompression is recommended for facial nerve paralysis caused by chronic ear disease. Surgical decompression of the nerve is usually unnecessary for patients with acute otitis media and is offered to those patients who fail to respond to the usual treatment with myringotomy and antibiotics and/or whose nerves undergo degeneration as determined by electrodiagnostic tests.

Labyrinthitis

Labyrinthitis is the most frequent complication of otitis media due to extension of infection within the temporal bone. Three types of labyrinthine inflammation may occur as a complication of acute otitis media and mastoiditis. They are, in the order of ascending severity, perilabyrinthitis, perilabyrinthitis, serous labyrinthitis, and suppurative labyrinthitis.

Perilabyrinthitis (Labyrinthitis Fistula). Perilabyrinthitis may be surgically produced (simple or radical mastoidectomy, fenestration, labyrinthotomy, or stapedectomy) or it may occur spontaneously due to bone erosion by cholesteatoma. A spontaneous fistula usually results from erosion of one of the semicircular canals, especially the lateral semicircular canal.

28 The most common severe complication from cholesteatoma is fistulization of the horizontal semicircular canal.

The diagnosis of labyrinthine fistula is established by eliciting the fistula sign. This consists of nystagmus and vertigo when positive and negative pressure is applied to the soft tissue covering the fistula. The nystagmus is produced by a movement of endolymph toward the ampulla with inward pressure displacement, with the quick component toward the affected ear. With negative pressure there is outward displacement and a movement of endolymph away from the ampulla, with the quick component of nystagmus toward the normal ear. The absence of the fistula test does not rule out the presence of a fistula. A positive fistula test is present in two-thirds of the cases with a labyrinthine fistula. The presence of a fistula in the horizontal semicircular canal may be demonstrated on the AP polytome x-ray.

The patient with an active fistula of the labyrinth often complains of dizziness if he presses against the tragus, manipulates the auricle, or quickly turns the head. Rarely, he may experience momentary vertigo when exposed to a loud noise (Tullio's phenomenon).

A strong positive fistula sign is always an indication for surgical examination of the labyrinth. When erosion is associated with chronic otitis media, a radical or modified radical mastoidectomy must be performed to eradicate the pathologic condition. In this way, spread of infection into the labyrinth can be prevented.

The cholesteatoma matrix can be removed with reasonable safety from most small (less than 2 mm) semicircular canal fistulae. When the matrix is firmly adherent to a large area of the membranous semicircular canal, its removal is not recommended because of a high incidence of postoperative sensorineural disease. When the fistula involves the cochlear wall, the cholesteatoma matrix should not be removed. Its removal carries a high risk of postoperative sensorineural deafness. If the contralateral ear has no auditory function and the ear with the fistula is the only hearing ear, the cholesteatoma matrix over the fistula is best left undisturbed. In such cases, the cavity should be kept open and the patient should be followed closely to determine if further active suppuration develops.

Serous Labyrinthitis. Serous labyrinthitis is a diffuse intralabyrinthine inflammation without pus formation, and is not followed by permanent loss of auditory and vestibular function. It is, however, a prepurulent condition and a potential precursor of suppurative labyrinthitis.

The treatment of serous labyrinthitis secondary to acute otitis media is primarily medical with a large dosage of antibiotics. Surgery is mandatory in chronic infections when serous labyrinthitis develops.

Suppurative Labyrinthitis (Purulent Labyrinthitis). Suppurative labyrinthitis is a diffuse intralabyrinthine infection with pus formation and is associated with permanent loss of auditory and vestibular function.

This may occur as a result of direct extension of the purulent process in the middle ear or mastoid into the labyrinth, or it may result from the spread of meningeal inflammation

29 into the labyrinth through the internal auditory canal or less frequently through the cochlear aqueduct.

Clinical symptoms include nausea and vomiting, intense vertigo, tinnitus, hearing loss, and nystagmus.

Treatment should consist of intense antibiotic treatment and surgical drainage of the labyrinth.

Petrositis

Petrositis is an inflammation of the petrous portion of the temporal bone, characterized by that clinical triad of otitis media, paralysis of the sixth cranial nerve, and pain of the fifth cranial nerve (Gradenigo's syndrome). The symptoms of petrositis depend upon the area of the petrous pyramid affected.

Past the age of 3 years approximately 30% of the temporal bones have pneumatization in the petrous apex. Even the pneumatized petrous apex has unpneumatized areas containing marrow. This makes this site more susceptible to osteomyelitis. Air cells extend into the petrous pyramid in two main groups: a posterior group from the epitympanum and antrum, around the semicircular canals into the base of the pyramid, not infrequently extending to the apex; and an anterior group from the tympanum, hypotympanum and eustachian tube, around the cochlea into the apex of the pyramid. The posterior group of cells is present in about 30% of the temporal bone, whereas the anterior group of cells is present in about 15% of the temporal bones.

Additional symptoms of petrositis, although not frequent, include transient facial weakness, mild recurrent vertigo, and fever. If the suppuration extends beyond the petrosa, there may be added symptoms of localized and/or generalized meningitis; a cerebellar or a temporal lobe abscess; thrombophlebitis of the inferior petrosal sinus and jugular bulb; or a lateral pharyngeal, retropharyngeal, or deep neck abscess (Bezold's abscess).

Petrositis should be suspected in any patient whose ear continues to drain after surgery for chronic infection, or in any patient with ear disease who complains of persistent pain that is otherwise unexplained.

Treatment is by surgical drainage. A systematic search of the common pathways for extension of infection into the petrous area must be undertaken. The easiest and safest surgical approach to infected petrous cells is along the route by which the cells invaded the petrosa. Surgical drainage should always be preceded by a complete simple mastoidectomy for the posterior group of cells, and a radical mastodiectomy for the anterior group of cells. Care must be taken to prevent injury to the carotid artery in exploring the anterior cell group.

Extradural Abscess

An extradural abscess if a collection of pus between the dura and the bona. Apart from coalescent mastoiditis, this is the most common complication of otitis media. It is usually secondary to bone erosion rather than a result of osteothrombophlebitis or via preformed

30 pathways. If the pus lies against the dura of the posterior fossa medial to the sigmois sinus, it is called an extradural or epidural abscess. If it lies against the split of the posterior fossa dura enclosing the lateral sinus, it is called perisinus abscess.

The most common symptom is persistent headache, however, many extradural abscesses are unnoticed before surgery. Other symptoms include an unusually severe earache and a malaise with low-grade fever. Marked pulsation of the purulent discharge accentuated by compression of the jugular vein is noted. One clinical feature that is somewhat pathognomonic of an extradural abscess is relief of headache by profuse drainage from the ear. The treatment is surgical drainage.

Subdural Abscess

A subdural abscess develops when pus accumulates between the dura and the arachnoid. This is uncommon. This may develop as a result of extension of an infection of the middle ear and mastoid through the intact bone and the dura by means of a thrombophlebitis of the veins or by direct extension with erosion of bone and dura.

The symptoms include headache, malaise, delirious state, focal seizures, and other neurologic signs such as hemiplegia, aphasia, or hemianopsia. Signs of meningeal irritation almost always are present.

Attacks of jacksonian epilepsy with hemiplegia developing in association with middle ear infection should be regarded as indicative of subdural abscess until proved otherwise. Treatment is surgical drainage of the subdural space.

Brain Abscess

Otogenic brain abscess occurs usually in the temporal lobe of the cerebrum (more frequent) or in the cerebellum. It is to be the most frequent cause of death from otitis media.

The abscess may develop as a result of direct extension of the otologic infection, by means of thrombophlebitis, or along the preformed pathway. It may result from a previous skull fracture. An extradural abscess usually forms before the development of a brain abscess. Cerebellar abscesses from otitis media usually form through preformed pathways, whereas temporal lobe abscess results from seeding through bone erosion. Three clinical stages of brain abscess have been observed:

The first stage of initial encephalitis. Elevation of temperature, headache, nuchal rigidity, or other meningeal signs often are noted.

The second latent or quiescent stage. The symptoms are minimal or absent as an abscess is becoming organized and beginning to expand. This stage may last several weeks. The patient may complain of headache, irritability, or lethargy.

The third stage of an expanding abscess. The symptoms and signs of this stage are due to generalized increased intracranial pressure and localized pressure on brain centers. They include severe and continuous headache (the most constant symptom), projectile vomiting,

31 slowing of the pulse, Cheyen-Stokes respiration, apathy and drowsiness, change in mental activity, disorientation, jacksonian convulsions, ocular paralysis with pupilllary changes, hemianopsia, aphasia, and elevated blood pressure. The most constant signs of increased intracranial pressure occur in the eyeground with blurring of the disc margins, hyperemia, or papilledema.

A left temporal lobe abscess in the right handed patient most commonly results in nominal aphasia. The next most common finding is paresis of the contralateral face and mouth, spreading to the extremities. A right temporal lobe abscess in a right-handed patient results in paralysis and numbness of the left side.

A cerebellar abscess usually gives more localizing signs. Among them are:

1. Ataxia (tendency to fall to the diseased side).

2. Ipsilateral hypotonia and weakness.

3. Spontaneous vertical or variable nystagmus.

4. Rapid emaciation.

5. Dysdiadochokinesia.

6. Intention tremor with past-pointing.

Diagnosis. Otogenic brain abscess is suggested by the characteristic clinical features described above in a patient with a coexisting or preexisting suppurative otitis media. Definitive diagnosis of brain abscess is made by special neurosurgical procedures which include lumbar puncture, ventriculography, angiography, electroencephalography, brain scanning, computerized tomography, and brain puncture. Ultimate diagnosis is made by finding the pus by brain puncture via a burr hole.

A lumbar puncture shows an increase in cerebrospinal fluid pressure and protein. A lumbar puncture is valuable in differentiating a brain abscess from other otogenic intracranial complications. However, it should be noted that a lumbar puncture in an advanced brain abscess with increased intracranial pressure can be followed by death as a result of herniation of the brain stem into the foramen magnum. A cerebellar abscess seldom reaches a large size since it is near the respiratory center. Compression of this center results in respiratory arrest and death. A temporal lobe abscess can keep expanding until it ruptures into the fourth ventricle causing fulminating meningitis. The treatment is primarily surgical drainage and an intense course of antibiotics.

Lateral Sinus Thrombophlebitis

Lateral sinus thrombophlebitis usually develops as a consequence of erosion of the lateral sinus plate by coalescent mastoiditis or chronic mastoiditis. First a perisinus abscess is formed. A mural thrombus then develops in the walls of the sinus, becomes infected, and spreads proximally and distally. The lumen of the sinus is eventually occluded by the

32 increased thickness of the infected clot and by clotting of the stagnant blood. The ends of the infected clots then soften and infected material continues to escape into the systemic circulation (septicemia). Lateral sinus thrombophlebitis also can be caused by infections of the scalp or adjacent bones along the mastoid emissary vein. The usual organisms are hemolytic streptococci and pneumococci.

The clinical features vary according to the stage of the infection. When a perisinus abscess develops, headaches and malaise are usually the only symptoms. When the mural thrombus becomes infected within the vessel, septicemia develops with septic fever and chills. The primary symptoms of lateral sinus thrombophlebitis may be a persistent and spiking type of fever ("picket-fence"). Between bouts of fever the patient is often alert and feels well. Anemia may develop. With occlusion of the lumen of the sinus, interference with cerebral circulation results in headaches, papilledema, and increased cerebrospinal fluid pressure. When the thrombophlebitis spreads to the mastoid emissary vein, edema and tenderness may be produced over the mastoid process (Greisinger's sign). When the thrombophlebitis spreads to the jugular bulb and internal jugular vein, it may produce pain in the neck particularly on rotation of the neck. This may simulate neck rigidity of diffuse meningitis. The clot may be felt as a tender cord in the neck. The ninth, tenth and eleventh cranial nerves are occasionally paralyzed by the pressure of a clot in the jugular bulb.

The diagnosis is based upon positive blood cultures taken during the febrile phase, and the demonstration of lateral sinus obstruction by a Tobey-Ayer or Queckenstedt's test. With the spinal needle in place, digital pressure is applied over the internal jugular vein in the neck. This maneuver on the normal side produces a prompt rise in the spinal fluid pressure, but no increase on the side of the lateral sinus obstruction.

The treatment is always surgical. The sinus should be completely uncovered and the perisinus abscess eradicated. A needle aspiration of the sinus will determine if the sinus is occluded. If the sinus is occluded and there is an intrasinus abscess, it is necessary to open the sinus and remove the infected thrombus. When embolism or cavernous sinus thrombosis appears to be developing, anticoagulation together with intensive antibiotic therapy is recommended. Ligation of the internal jugular vein may be necessary.

Lateral sinus thrombophlebitis has been said to be the second common cause of death from otitis media.

Meningitis

Meningitis is the most common intracranial complication from suppurative otitis media and mastoiditis. There are two types of meningitis: localized and generalized.

1. Localized or circumscribed meningitis (no bacterial organism present in the spinal fluid).

2. Generalized meningitis (bacterial organisms are present in the spinal fluid). The patient suddenly becomes very ill and restless with severe headache, vomiting, and pyrexia, but soon loses consciousness. The classic signs of meningitis soon appear: stiffness of the neck, positive Kernig's sign, nausea and vomiting, and delirious and confused mental state or

33 coma. In children, convulsions, a low, weak cry, and bulging fontanelle suggest meningitis until proved otherwise. The cerebrospinal fluid looks turbid and shows an increase in pressure and cell count. The protein concentration is raised, but the glucose and chloride are reduced. In generalized meningitis, numerous microorganisms can be found.

Treatment of meningitis is chemotherapeutic. Surgery is indicated in those patients developing meningitis secondary to chronic otitis media when the patient's general condition permits.

Otitis Hydrocephalus

Otitic hydrocephalus is a syndrome of increased intracranial pressure without a brain abscess following several weeks or more of acute otitis media. The condition occurs most often in children and adolescents. The most constant symptom is headache, often with a sixth nerve paralysis on the same side, sometimes with vomiting. Otherwise tghe patient looks and feels quite well. The most constant findings are papilledema and spinal fluid pressure

exceeding 300 mmH2O. Unlike localized meningitis the spinal fluid is clear without increased cell count or protein content. There are no localizing neurologic changes. Ventriculography fails to show a space-occupying lesion.

The exact mechanism of increased cerebrospinal fluid pressure is not known, but it is assumed to be due to increased production or decreased resorption of cerebrospinal fluid secondary to a previous meningeal inflammation. Treatment is repeated lumbar puncture. Subtemporal decompression may become necessary.

Congenital Cholesteatoma (Epidermoid) of the Temporal Bone

Congenital cholesteatomas or epidermoids arise from aberrant epithelial remnants and are, therefore, considered blastomatous malformations. Their predilective sites are the intracranial cavity, the diploe of the skull, and the spinal canal. In the base of the skull the temporal bone is the most frequent site.

Epidermoids accout for about 0.2-1.5% of all intracranial tumors. The majority originate in the cerebellopontine angle where they account for 6-7% of all tumors. Their age incidence reveals a great scatter from birth to 80 years. The majority are recognized during the third and fourth decades with the onset of clinical symptoms occurring much earlier. They affect males more frequently than females. Their delicate capsule with a whitish, mother-of- pearle sheen lends them a typical appearance.

Epidermoids are generally slow growing lesions which may remain asymptomatic for years. The irritative effect of their content, however, can produce symptoms of dysfunction and intense inflammation. Malignant changes occur infrequently. Diploic epidermoids are easily recognized, whereas intradural epidermoids are more difficult to identify.

Epidermoids may arise in the vicinity of, on the outer aspect of, or within the temporal bone. Epidermoids originating in any of these locations have certain characteristic features which may arouse suspicion of their presence. Examples of an epidermoid with origin in the

34 typical locations within the temporal bone and cerebellopontine angle are discussed to portray their individual characteristics (Laryngoscope 85 suppl, 2, December, 1975).

35 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 8: Noninfections Diseases of the Ear

Histopathology of Otosclerosis

This bony disorder of the otic capsule assumes various histopathologic characteristics throughout its development. The early state is characterized by bone resorption and loose spongy bone widely interspersed with multiple vascular spaces. The more mature state, being denser, is characterized by fewer vascular spaces and by redeposition of bone. Otosclerotic bone can involve all three layers of the otic capsule (endosteum, endochondral, and periosteal) though it is said to begin at the endochondral layer. The involved endochondral layer lacks the typical "globuli ossei" (islands of ossified cartilage) of normal endochondral bone. Both osteoblastic and osteoclastic activities take place in otosclerosis. It is believed that the otosclerotic process starts with fingerlike invasion along blood vessels. On hematoxylin-eosin (HE) stain, this invasion appears bluish and is thus named the "blue mantle of Manasse". Histologic otosclerosis exists in about 8-10% of the white race; it is rarer among Orientals and blacks. The incidence among East Indians, however, is believed to be comparable to that of the white race. Clinical otosclerosis is estimated to account for 1% of conductive hearing loss in the white population.

The sites of predilection for otosclerotic involvement are:

1. Just anterior to the oval window (80-90% of the temporal bone with otosclerosis).

2. The border of the round window (30-50%).

The incidence of bilateral involvement is about 75-85% among temporal bones with otosclerosis. This disease shows a familial tendency; 60% of the patients with clinical otosclerosis have a positive family history. Some investigators believe it to be transmitted by a monohybrid autosomal-dominant gene with 25-40% penetrance; others believe that it may be transmitted by an autosomal-receissive gene. Among those with hearing loss, a positive family history can be obtained from 50-60%. The risk of an increasing hearing loss for any one pregnancy in a woman with stapedial otosclerosis is 1:4. If one parent has clinical otosclerosis, the children have a 20% chance of developing clinical otosclerosis.

Clinically, two eponyms are attached to otosclerosis: Schwartze's sign and Carhart's notch. Schwartze's sign is the reddening of the promontory seen through a translucent tympanic membrane. This supposedly represents the increase of vascular spaces in the periosteal layer of the promontory. Carhart's notch is a depression of the bone conduction threshold, greatest at 1000 or 2000 Hz. The Carhart's notch is eliminated after a successful stapedectomy, suggesting that it is not sensorineural, but rather is due to the impairment of bone conduction by a fixed footplate.

Malleus fixation caused by bone ankylosis between the head of the malleus and the tegment can give a conductive hearing loss similar to that of stapes fixation. The incidence of malleus ankylosis coupled with stapes fixation by otosclerosis has been estimated to be about 1.6% of the patients.

1 Paget's disease (osteitis deformans) is histopathologically very similar to otosclerosis. The main differences are:

1. Paget's disease has diffuse involvement whereas otosclerosis is limited to the temporal bone.

2. Otosclerosis involves all three layers of the otic capsule (endosteal, endochondral, and periosteal), whereas Paget's disease involves mainly the periosteal layer.

3. Osteitis deformans seldom involves the footplate or any part of the ossicles.

Osteogenesis imperfecta tarda is a systemic disease in which there is abnormal osteoblastic activity resulting in resorption of bone. This is an autosomal-dominant disease and is characterized by the patient with multiple fractures. Forty to sixty percent of these patients also have bluish-colored sclerae together with stapes fixation. This constellation of findings has been referred to as the van der Hoeve-de Kleyn syndrome.

Complications of Stapedectomy

Some of the complications of stapedectomy may indeed stem from inadequate preoperative evaluation and poor selection of the patients for surgery. To prevent unnecessary and avoidable complications, some of the suggestions by experienced otologists are as follows:

1. The minimum audiometric test requirements are pure tone bone- and air-conduction thresholds, speech reception levels, and speech-discrimination scores. The intelligent use of masking is highly important. The audiometric test results should always coincide with those of the tuning fork test. If they do not, do not proceed with surgery, but search for an explanation for the discrepancy. It may be due to a "shadow curve" from poor masking.

2. A sufficient conductive hearing loss should be confirmed by a negative Rinne test for at least two of the three speech frequencies.

3. A careful assessment of discrimination ability is essential. The ear that discriminates better should not be operated upon because of the risk of postoperative sensorineural deafness.

4. Stapedectomy when indicated should be performed in the worse hearing ear first. If a successful result is achieved, the operation on the second ear can be considered 12 months or more later.

5. This operation should never be done in an only-hearing ear.

6. The pros, and especially the cons of this operation should be carefully discussed with the patient before surgery. The patient should be advised of the chief risk of the operation, namely postoperative sensorineural deafness, and other possible complications.

7. Patients with otosclerosis rarely complain of vertigo. When there is vertigo and clinical evidence of coexisting labyrinthine hydrops (Ménière's disease), stapedectomy should

2 not be carried out for fear of a "dead ear". The distended saccule which may be in contact with the footplate, may de damaged during stapedectomy.

8. Stapedectomy should never be carried out in the presence of external otitis. The ear canal should be carefully examined the day before the operation and external otitis ruled out.

9. There is a higher incidence of failure in younger individuals because of the activity of the otosclerotic growth. This probably results from stimulation of the otosclerotic growth by stapedectomy.

10. Some otologists feel that stapedectomy should never be done in children because the risk of poststapedectomy sensorineural loss is high, especially if the preoperative bone conduction is poor. Bilateral infantile cases should be advised to wear a hearing aid until older.

11. The risk of prolonged postoperative vertigo is small but should be a consideration for some patients, i.e. professional athletes, high construction workers, roofers, and other individuals whose livelihood depends on special motor skills.

12. For patients engaged in frequent air travel, underwater sports, or other activities associated with unusual alterations in atmospheric pressure, Schuknecht suggests the use of a large fatty connective tissue graft and a shorter prosthesis.

13. Stapedectomy may result in worsening of speech discrimination. The elimination of stiffness by successful stapedectomy in a patient with a descending pattern of bone- conduction thresholds converts the pattern of air-conduction thresholds from flat to descending (paralleling the bone conduction) and results in a loss of speech discrimination. This discrimination is caused by the descending gradient of threshold sensitivity, not by morphologic changes in the inner ear. When this condition has been produced by the first stapedectomy, stapedectomy on the second ear should be discouraged.

14. Large exostoses of the external auditory canal may interfere with the surgical approach. In such cases, it is best to remove the exostoses first and to delay stapedectomy for several months.

Complications Encountered During Stapedectomy

Complications encountered during stapedectomy include tears of the tympanomeatal flap, dislocation of the incus, fracture of the long crus of the incus, cerebrospinal fluid leak, bleeding, vertigo, depressed footplate, and floating footplate. Exostoses, superiorly located jugular bulb, overhanging facial nerve, round window otosclerosis, persistent stapedial artery, malleus ankylosis, congenital anomalies of the stapes and incus, and obliterative otosclerosis also present problems during stapedectomy.

Tears of the Tympanomeatal Flap

A linear tear may require no repair. Most tears can be satisfactorily repaired with fat from the earlobe, temporalis fascia, or tragal perichondrium. A flat piece of tissue of suitable

3 size is introduced into the perforation with the graft on the medial surface. The margins of the perforation are approximated as closely as possible.

Dislocation of the Incus

1. Subluxation of the incus consists of a tear of the incudomaleal joint but with sufficient intact capsule to maintain the incus in its normal anatomic position. Although the long process of the incus will be excessively mobile, the operation may be completed and the functional result may be satisfactory.

2. Luxation of the incus is due to a complete disruption of the incudomalleal joint and demands that the incus be removed and a malleus-oval window prosthesis be utilized. Attempts to replace and maintain the incus in its original position usually are not successful. The incus may be accidentally dislocated during curetting of the bony annulus and during extraction of the stapes. The long process of the incus may be accidentally displaced when withdrawing hooked instruments from the oval window niche.

Fracture of the Long Process of the Incus

This complication is rare. If the fracture occurs near the tip of the long process, the wire prosthesis may be placed on the stump. If the stump is too short, a malleus oval window prosthesis should be used. When the lenticular process is particularly long, and close to the promontory, it is advisable to fracture and shorten it to prevent a fibrous adhesion to the promontory.

Cerebrospinal Fluid Leak

In about 1:300 cases, opening of an oval window reslts in a sudden profuse flor of clear fluid. Those ears apparently have large patent cochlear aqueducts through which cerebrospinal fluid enters the inner ear. The fluid traverses the scala tympani to the helicotrema and then passes through the scala vestibuli to the vestibule to reach the oval window. In these cases, the fat graft technique is preferred and the patient is maintained in a head-elevated position for several days post-operatively. Cerebrospinal fluid flow is more common in cases of congenitally fixed stapes.

Bleeding

All bleeding from the ear canal should be controlled before the middle ear is opened. Bleeding from the mucous membrane of the oval window usually subsides spontaneously, but if necessary, may be controlled by pressure applied with a cotton pledget or Gelfoam soaked with epinephrine. Occasionally there are large vascular channels in the otosclerotic bone which may bleed during footplate removal. Thus bleeding into the vestibule may be unavoidable. Most otologists prefer to leave the clot in the vestibule untouched to complete the stapedectomy. A blood clot in the vestibule does not compromise the end result.

4 Vertigo

Vertigo occurring during the stapedectomy operation is either due to mechanical stimulation of the vestibular sense organs or to cold caloric stimulation. One of the advantages of using local anesthesia is to permit this symptom to be monitored during surgery.

The aspiration of perilymph and its replacement with air results in displacement and collapse of the vestibular labyrinth and is associated with vertigo. Manipulations within the vestibule may cause vertigo. No instrumentation should be performed with the vestibule, and any manoeuver which creates vertigo should be avoided. A fragment of footplate or a "broken" instrument which has fallen into the vestibule should be left alone. Attempts to remove it are followed by a high incidence of sensorineural hearing loss.

The introduction of a prosthesis which is too long may cause vertigo. The proper length should be determined by measurement. Before a prosthesis is tightened to the incus it should be determined if vertigo is elicited by an inward movement of the prosthesis. This is particularly important when fitting a piston prosthesis.

When perilymph has been removed, the utriculus may assume an abnormally superior position in the vestibule. In this position it will be free from possible contact with a prosthesis during surgical procedure, but it will return to its normal position subsequently, as perilymph is reformed. This constitutes an important reason for avoiding loss of perilymph.

The pooling of an anesthetic agent in the round window niche may lead to its resorption into the inner ear and result in vertigo and nystagmus. During the injection procedure, care should be used to avoid allowing the anesthetic agent to enter the middle ear.

Depressed Footplate

Every effort should be made to avoid a depressed footplate. A severely depressed footplate or footplate fragment should be left in the vestibule and a Gelfoam wire or tissue wire prosthesis introduced in the usual manner. These patients usually experience postoperative vertigo for several weeks and unsteadiness for many months.

Floating Footplate

The two conditions which lead to a floating footplate are previous stapes mobilization and minimal stapes fixation. When these conditions exist, a small opening should be created in the footplate before removal of the superstructure. This opening should be large enough to admit a 0.3 mm hook. If in spite of adequate precautions the floating footplate occurs, its removal must be effected through an inferior margin burr hole. A 0.5 mm sharp cutting burr is used to make a notch in the inferior margin of the oval window.

Complications Following Stapedectomy

Postoperative complications following stapedectomy include acute otitis media, suppurative labyrinthitis and meningitis, vertigo, reparative granuloma, perilymph fistula, facial paralysis, fluctuating conductive hearing loss, persistent perforation of the tympanic

5 membrane, taste disturbance and dry mouth, postoperative fibrosis, incus necrosis, and delayed sudden deafness.

Acute Otitis Media

To prevent this complication, many otologists prescribe antibiotics. Acute infections should be treated intensively with the appropriate antibiotics as determined by culture and sensitivity studies.

Suppurative Labyrinthitis and Meningitis

The most serious complication of stapedectomy is suppurative labyrinthitis leading to meningitis. Although it is extremely rare, several deaths from this complication have occurred. Presumably the bacterial invasion occurs through a thin membrane or fistula of the oval window. There is a higher incidence of meningitis with a polyethylene strut than with other tissue-wire prosthesis. Patients having had stapedectomy should be counseled about the importance of prompt treatment of respiratory infections when they are associated with ear discomfort.

Postoperative Vertigo

Vertigo may occur immediately following stapedectomy, or its onset may be delayed. Immediate postoperative vertigo is a result of perilymph loss, direct surgical trauma, or postoperative serous labyrinthitis, and it usually subsides within a few days. When vertigo or a sensation of unsteadiness persists for longer than a few days, a search for the cause should be made. Possible causes are: depressed footplate, reparative granuloma, excessively long prosthesis, and an oval window fistula. The long prosthesis is readily detected by eliciting the fistula response with the pneumatic otoscope. The exact position of the metallic prosthesis may be demonstrated by polytomography. Surgical intervention may be required not only for the comfort of the patient, but also to preserve inner ear function. Positional vertigo of the benign paroxysmal type (cupulolithasis) may follow stapes surgery and probably is due to injury to the utricle with release of otoconia. This type of vertigo is usually self-limiting, but it may persist for several months or years.

Reparative Granuloma

Granuloma of the posterior mesotympanum occurs as a complication of stapedectomy in approximately one or two out of 100 cases. The condition usually becomes manifest between the seventh and fifteenth postoperative days. Progressive sensorineural hearing loss after an initial hearing gain in the earliest and most consistent symptom. Vertigo, tinnitus, and sensation of fullness in the ear may be present. Reparative granulomas are associated with serous labyrinthitis in the early stages and serofibrinous labyrinthitis in the later stages when the inner ear damage becomes permanent. (Kaufman, R. S. and Schuknecht).

Examination reveals an edematous thickened tympanic membrane with redness in its posterior half. Audiometric tests show a combined sensorineural and conductive hearing loss worse in the high frequencies and with marked decrease in speech discrimination. Emergency

6 surgical intervention is imperative in these patients. Complete removal of granuloma within the first two poststapedectomy weeks may prevent permanent sensorineural hearing loss.

Perilymph Fistula (Oval Window Fistula)

The incidence of oval window fistula following a stapedectomy varies from 0.3% in 1772 patients to 2.5% in 1784 patients. The symptoms of perilymph fistula are similar to those of endolymphatic hydrops. A sudden decrease in hearing often with vertigo and unsteadiness, a sense of fullness in the affected ear, and sometimes roaring tinnitus, are common symptoms. Gradual progressive deterioration, but with fluctuation, is the rule in perilymph fistula.

The symptoms of oval window fistula may be evident within a few days or weeks following stapedectomy, or may be delayed for weeks or months. The delayed type of fistula is especially common after insertion of a polyethylene tube or Teflon prosthesis. The incidence is higher with a wire-Gelfoam prosthesis than with a wire-tissue prosthesis.

The treatment of perilymph fistula is unsatisfactory in most cases as far as hearing is concerned, but satisfactory for elimination of vertigo and risk of meningitis. Removal of the entire membrane from the oval window and replacing it with a wire-tissue prosthesis usually will stop the leakage of perilymph and the fluctuating symptoms, including vertigo. Early recognition and treatment may enable recovery of hearing to the previous good level.

Facial Nerve Paralysis

Immediate facial paralysis usually results from the local anesthetic reaching the facial nerve. Recovery of facial function is complete in 2-4 hours. If immediate paralysis persists, surgical trauma is likely and the nerve should be explored and decompressed within 24 hours. Direct instrument injury to the facial nerve is rare, but extreme caution should be used to prevent this complication. Approximately 50-60% of patients have dehiscence of the inferior aspect of the facial canal. Facial paralysis that begins several days after operation may be assumed to be the result of edema of the facial nerve.

Fluctuating Conductive Hearing Loss

Fluctuating conductive hearing loss is the result of loose linkage of either end of the prosthesis. A faulty linkage characterized by intermittent contact with the oval window membrane causes large fluctuations in hearing and is corrected by introducing a longer prosthesis. Loose linkage on the incus is characterized by small fluctuations in hearing, and is corrected by either tightening the wire loop or by removing the prosthesis and replacing it with a properly tightened wire hook.

Although hearing impairment with perilymph fistula is predominantly of the sensorineural type, a fluctuating or persistent conductive loss may be caused by perilymph fistula. This is considered to be due to the "backsplash" of a leaking vestibular perilymph space.

7 Perforation of Tympanic Membrane

A small postoperative perforation will usually heal spontaneously. Large perforation due to surgical trauma or postoperative infection require later myringoplasty.

Taste Disturbance and Dry Mouth

Stretching, tearing, or cutting the chorda tympani nerve can cause loss of taste on that side of the tongue and dryness of the mouth. Dryness of the mouth may be a particularly disagreeable poststapedectomy complication if both nerves are damaged. Some otologists feel that the patient has fewer symptoms when the chorda tympani nerve is cut than when it is overstretched.

The disturbance of taste, dryness of the mouth, and numbness of the anterior part of the tongue after trauma or section of the chorda tympani nerve, begin to lessen in a month or two and usually disappear after 3 or 4 months; but they may persist longer or can be permanent.

Postoperative Fibrosis

A fibrous band from the incus to the promontory is a common cause for incomplete closure of the bone-air gap. The incidence of this complication can be minimized by avoiding surgical trauma to the mucosa of the promontory. Corrective surgery includes removal of the fibrous band and introduction of a Teflon or Silastic disc.

Incus Necrosis

Pressure necrosis of the tip of the long process of the incus appears to be caused by direct surgical trauma or by the irritation of the prosthesis. The incidence of this complication is highest with polyethylene tube prostheses in which case the resorption is due to osteitis initiated by foreign body reaction. A loosely crimped wire also can produce a low-grade reaction and local bone resorption. For this reason the loop of the prosthesis must be secured tightly to the incus.

Delayed Sudden Sensorineural Hearing Loss

This is a rare complication of stapedectomy and may be caused by alterations in atmospheric pressure such as are experienced in an airplane or elevator. It is most common in patients who have had a polyethylene tube prosthesis inserted and is usually accompanied by severe vertigo and profound hearing loss. Presumably in these cases the prosthesis has been displaced into the vestibule.

Sudden profound sensorineural hearing loss, without vertigo and without obvious provocation, may occur some months or years following stapedectomy, particularly after revision procedures.

8 Recent Studies on Stapedectomy

Small-Fenestra Stapedectomy

1. A small-fenestra stapedectomy is based on the rationale of creating a more effective acoustic mechanical transmission system, while reducing potential labyrinthine disturbance. The surgical technique for the small-fenestra stapedectomy described by Bailey at al, includes the creation of the fenestra and the use of a McGee stainless steel piston prosthesis with loose areolar tissue around the piston. Postoperative results are compared in a series of 100 cases, 50 having the small-fenestra technique SFT) and 50 having a partial or total footplate removal procedure. Vestibular results demonstrate a noticeable reduction in postoperative complaints of balance disorders in the SFT patients. Hearing results, when compared between the two groups, show a statistically significant advantage for the SFT patients in postoperative high- frequency threshold sensitivity and speech discrimination scores. The advantages of lowered risk, based on reduced trauma to, and contamination of, the labyrinth, as well as improved high-frequency hearing sensitivity and speech discrimination, support the procedure according to Bailey et al.

2. McGee analyzed the results of 280 consecutive stapedectomies. One hundred forty- one (141) operations were done using the "total stapedectomy" technique, and 139 were done using the "small-fenestra" technique. The auditory acuity of the two groups was compared with reference to conductivew and sensorineural performance. The data supported the author's original impression that the small-fenestra technique is the treatment of choice in the surgical management of clinical otosclerosis.

3. According to B. Farrior, the small-hole stapedectomy with a bare piston is contraindicated when there are excessive fluid pressure changes in the inner ear and when there are excessive air pressure changes in the middle ear. The small-hole stapedectomy is the operation of choice in thick fooplate or obliterative otosclerosis which requires the use of the hand or power drill to create an opening in the oval window. When a small-hole stapedectomy is attempted and there is a tilting of a portion of the footplate, the footplate should be removed and the window sealed with a graft.

Complications of a small-hole stapedectomy are rare but consist of fistulas, a tented piston, a dislocated piston, or a partial closure with a tilted footplate. Complications of a small-hole stapedectomy may be reduced by placing a thin tissue graft over the foot of the piston, a socked piston, or a capped piston.

Total Stapedectomy

The concept of total footplate removal in stapedectomy is recommended by Robinson as the preferred technique, providing that the surgery is atraumatic. Only that part of the footplate which can be removed easily should be removed; in 4671 consecutive stapedectomies a total footplate removal could be accomplished in 74%. Total and partial footplate removal necessitates a connective tissue graft to seal the oval window and must be coordinated with a suitable prosthesis whcih is efficient, functional, and self-centering. The successful results between total and partial footplate removal are not statistically significant when employing the criteria of air-bone gap closure to within 10 dB, but when comparing the

9 complete air-bone gap closure rate there is a statistically signigicant difference with total footplate removal providing a more favorable hearing result.

Revision Stapedectomy

1. Sheehy et al reviewed the records of 258 revision stapedectomy operations performed during an 8-year period.

Displacement of the prosthesis to the inferior edge of the window was the most common cause of failure (41%) and occurred predominantly in wire-Gelfoam pad cases. An oval window fistula, a short prosthesis, or bony closure of the window were causes of failure in 9%. Incus necrosis was the cause of failure in 5%.

Less than 50% of the operations resulted in postoperative conductive deficit of 10 dB or less. The results were better in incus bypass procedures in revisions of patients in which a tissue graft was used over the oval window, and in revisions of ears initially operated on elsewhere. Severe sensorineural hearing impairment was the result in 7% of the operations and half of these impairments resulted in dead ears. The majority of these adverse results followed a repeat drill out of obliterative otosclerosis, or followed reopening of the oval window in patients with a postoperative inner ear problem other than a fistula.

They concluded that (a) revision stapedectomy is a less satisfactory procedure than primary stapedectomy; (b) there is rarely an indication for a repeat drill out of obliterative otosclerosis; and (c) the oval window membrane usually should not be disturbed in revision stapedectomy in a patient with inner ear symptoms unless there is a fistula.

2. In a study by Crabtree et al of 35 patients who underwent revision stapedectomy, revision stapes surgery improved hearing to a satisfactory level in fewer than half of the patients. The risk of sensorineural hearing loss is greater in revision surgery particularly if a sensorineural loss followed primary surgery.

Stapedectomy in Congenital Anomaly

Stapedectomy in a patient with congenital malformation of the middle and external ear should be done with caution. If there is a footplate, one should make the smallest possible diagnostic tap to rule out a profuse flow of cerebrospinal fluid. If none occurs, then one might consider stapedectomy and reconstruction.

Laser Stapedectomy

Argon laser stapedectomy was developed by Perkins. Fenestration of the stapes footplate with an argon laser microscope appears to be an advantageous method of restoring hearing in otosclerotic patients. The use of the laser, which gives increased precision and control to the surgeon, appears to be translate into a lower risk of negative results, less postoperative balance disturbance and better hearing when compared with current methods of management. This should mean shorter average hospitalization, less time away from work when analyzed from an economy viewpoint, and better hearing when viewed from the qulity- of-life standpoint.

10 Stapedectomy - Postmortem Findings

1. In reviewing histologic specimens of 16 temporal bones of 13 subjects who had stapedectomy operations, Schuknecht and Jones conclude:

Prostheses which overlap the margins of the oval windows result in an incomplete closure of the air-bone gaps. This is primarily a complication of methods which employ total removal of the footplate, and is caused by either improper placement or subsequent migration of the prosthesis. This problem can be minimized by careful centering of the prosthesis in the oval window or by the employment of partial stapedectomy in association with a piston prosthesis method in which the piston extends the vestibule.

b. Fibrous adhesions are a common consequence of trauma to the mucous membrane of the middle ear. Fibrous bands which extend between the lenticular process and promontory may cause incomplete closure of the air-bone gape. On the other hand, fibrous tissue which extends between the oval window and incus in association with the prosthesis appears to have little effect on sound transmission. The occurrence of fibrous adhesions can probably be minimized by avoiding trauma to the mucous membrane, particularly in the area of the promontory.

c. Gelfoam implantation following total stapedectomy promotes the formation of thin oval window membranes. However, even the thinnest membrane is at least as thick as the round window membrane. There is not evidence to suggest that the thin membrane is an inadequate seal for the oval window.

d. Thin membranes frequently show cupping (bulging out of the oval window), as a consequence of which the medial ends of the prostheses extend through the membranes. This condition appears to have no adverse effect on sound transmission.

e. Most inci show small areas of cortical bone resorption at the site of contact with the prostheses. However, the process appears to be self-limiting.

2. Two patients who developed sensorineural deafness following stapedectomy were studied by Schuknecht and Mendoza. A postmorted histologic study of one patient showed severe cochlear degeneration, presumably caused by necrosis of the fat graft. The study of the other patient showed that the prosthesis impaled the saccule, causing collapse of its wall with subsequent cochlear endolymphatic hydrops. An atraumatic surgical technique is strongly suggested.

3. Surgeons who perform stapedectomy for otosclerosis should be cognizant of the relevant surgical pathology to better assess their techniques and adopt methods which will optimize functional results and minimize complications.

Traumatic Perforation

Traumatic perforation can be caused by blast injury, welding injury, a force striking the auricle thereby occluding the external auditory canal (i.e. a slap with the open palm), and by a penetrating injury (i.e. Q-tip injury). There are many ways of treating these perforations

11 and the results are, to a large extent, comparable. Most otologists would agree that, without infection, 85-90% of all traumatic tympanic perforations heal spontaneously. However, whenever vertigo is associated with the injury, dislocation of the stapes is suggested, and hence surgical exploration should be performed as soon as possible. Among the above mentioned causes, a penetrating injury gives the highest incidence of stapes dislocation.

A small traumatic perforation without ossicular dislocation with no foreign body or squamous epithelium embedded in the mesotympanum can be treated expectantly. When no infection is evident antibiotic drops are not necessary. The use of 10% trichloroacetic acid and a paper patch (or Gelfoam) has been practiced by some otologists.

In the case of a large perforation without ossicular dislocation but with infolding of the edges of the perforation, the mesotympanum should be cleaned of foreign debris and the edges unfurled over a piece of adipose connective tissue or over pieces of Gelfoam. A tympanoplasty packing should be applied over this repair. In adults or in cooperative older children, this minor procedure can be performed under local anesthesia.

Whenever there is doubt as to the possibility of ossicular dislocation with a traumatic perforation, exploratory tympanotomy and tympanoplasty should be considered.

Sudden Deafness

Sudden deafness is defined as a sensorineural deafness that becomes instantly apparent, or one that rapidly develops over a period of hours or a few days. The hearing loss is often noticed on awakening in the morning, or during any of the days' activities such as those involving physical or emotional strain or even while at rest. Some patients do not complain about a hearing loss but may complain of stuffiness or blocked feeling in the ear or tinnitus. The hearing loss may range from mild to total and is typically unilateral although it may be bilateral. There may be an accompanying dizziness or vertigo (50%) but this is usually mild and typically improves over a period of a few days. Males and females appear to be equally affected.

Etiology

1. Frequently cited predisposing factors include changes in the physical environment such as altitude and other forms of change in atmospheric pressure, allergic manifestations, use of alcohol, emotional disturbances of the patient, physical exertion, diabetes, arteriosclerosis, pregnancy, use of a contraceptive drug, stress of surgery, and general anesthesia.

2. Specific etiologies that are well-documented are limited to viral agents. The sites of the viral-induced pathologic changes are the cochlea ("viral and endolymphatic labyrinthitis") and the components of the eight cranial nerve ("viral neuronitis and ganglionitis"). The viruses of mumps, measles, influenza, and adenoviruses may cause sudden deafness of the viral endolymphatic labyrinthitis type. The viruses of herpes zoster are the sole agents that have been shown to produce viral neuronitis and ganglionitis. The presence of active upper respiratory infection is noted in 25% of the patients at the onset of sudden deafness.

12 3. Vasospasm, thrombosis, embolism, hemorrhage into the inner ear, hypercoagulation, and sludging of blood frequently are considered as the most common causes of sudden deafness, but the evidence is lacking.

4. Cerebellopontine angle tumors (retrocochlear tumor) have been demonstrated to produce sudden deafness.

5. Simmons theorized a break in Reisner's membrane as a cause of sudden deafness resulting from sudden pressure changes (getting out of bed, sneezing, coughing, bending, performing a Valsalva maneuver, or scuba diving).

6. Goodhill recognized round window fistula as a cause of sudden deafness. Many reports of labyrinthine window ruptures followed. The anterior part of the oval window is the most likely area of rupture. The findings of positional nystagmus, a positive Romberg's or fistula sign with a sensorineural loss makes the diagnosis of an inner ear window rupture most probable. Tympanotomy is necessary to identify and close the fistula.

7. Morimitsu reported a new theory and therapy for sudden deafness. He treated 60 cases of sudden deafness with Urografin, injecting 1 mL intravenously the first day, then 2 mL injections daily until hearing reached the maximum recovering point.

Twenty-two of those cases have had a complete recovery. Eight have had a "remarkable recovery, meaning that there has been a hearing gain of more than 30 dB in the average threshold of 250, 500, 1000, 2000, and 4000 Hz". Three cases have shown slight improvement with average hearing gains between 10-30 dB. The remaining 27 cases have shown either no change or hearing threshold changes within 10 dB.

He noted that there was no improvement with Urografin in patients with vertigo. He also noted that recovery was almost complete in all test frequencies even in the patient treated 43 days after onset. Therefore, he believed that the lesion is probably not in the hair cells "which easily develop irreversible changes", but is a functional change in the cochlea. Based on the pharmacology of Urografin, Morimitsu has deduced that dysfunction occurs in the stria vascularis.

It is well established that both stria vascularis and the renal tubular epithelium are damaged equally by ototoxic antibiotics and the diuretics, furosemide and ethacrynic acid. Both diuretics deactivate the sodium-potassium ATPase in the stria vascularis, decreasing the endocochlear DC potential and cochlear microphonics, and the stria vascularis generates endocochlear DC potential.

If one assume that the hearing loss of sudden deafness is caused by a depression of endocochlear DC potential by whatever cause, then it is easy to understand why the hearing loss occurs suddenly, recovers quickly, and also very completely.

It is Morimitsu's theory that in sudden deafness of this type the blood-cochlear barrier is broken down at the area of the stria vascularis and that the molecular weight and character of Urografin is such that a little of it leaks into the circulation to fill the broken membrane

13 pores and reactivate the sodium pump to produce again normal DC potentials and also normal endolymph.

8. Wetmore and Abramson reported three cases of reversible sensorineural hearing loss associated with bullous myringitis.

9. Unilateral sudden sensorineural hearing loss after open heart surgery was reported by Plasses et al. All seven cases were male. The most likely cause is particulate microemboli generated by a cardiopulmonary bypass.

Classification

Sudden deafness may be classified from the etiological standpoint into two groups:

1. Localized lesions of the temporal bone:

a. Acoustic neuroma. b. Cerebellopontine angle tumor. c. Oval or round window fistula. d. Aneurysm of anterior inferior cerebellar artery.

2. Systemic diseases involving the temporal bone:

a. Viral infections which are cochleapathic. b. Accelerated coagulation. c. Hyperviscosity.

1) Polycythemia vera. 2) Macroglobulinemia.

d. Arteriosclerosis secondary to:

1) Aging. 2) Hypertension. 3) Diabetes. 4) Hyperlipidemia.

e. Collagen diseases.

f. Multiple sclerosis, syphilis, and many others.

Systemic Evaluation and Management

The evaluation and management of these patients with sudden deafness must proceed in a systematic fashion.

14 1. Otologic Examination.

Sudden deafness may be of a conductive or sensorineural type. These can be differentiated by otoscopic examination, tuning fork tests, and audiometric tests. When the tympanic membrane is normal, sensorineural loss is most likely present. Wax in the external auditory canal and serous or acute otitis media may often present as sudden conductive deafness.

Vestibular function tests should include spontaneous nystagmus, positional test, Rhomberg's gain, caloric test, and electronystagmography when indicated.

2. Audiogram.

The pure tone audiogram with air and bone conduction will confirm the clinical diagnosis of sensorineural loss. Cochlear or retrocochlear (eight nerve and cochlear nuclei) losses can be differentiated by special audiometric tests which include alternate binaural loudness balance (ABLB), short increment sensitivity index (SISI), discrimination score, tone decay, and Bekesy audiometry.

3. Coagulation Studies.

The sudden nature of sudden deafness suggests a sudden vascular occlusion which could arise from thrombosis of the cochlear vessels. Yet, many of the patients are young, without any evidence of arteriosclerosis, diabetes mellitus, hypertension, hyperlipidaemia, and other vascular diseases. Therefore, the possibility of a thrombosis arising from a hypercoagulated state is considered by Jaffe and multiple tests have been used to assess the presence of accelerated coagulation. About 40% of the patients have an increase in prothrombin consumption, a test which has proved to be the most sensitive indicator of accelerated coagulation. When the coagulation is normal, only about 25% recover. Other hematologic studies include CBC, platelet count, prothrombin time, and partial thromboplastin time (PTT). When the coagulation study is normal, proceed to number 5.

4. Viral Studies.

About 25% of patients with sudden deafness have an antecedent upper respiratory infection. The documentation of an acute infection should include virus isolation from swabs of the nasopharynx and a fourfold or higher rise of antibody titer when comparing the acute and convalescent sera. Specimens for virus studies should be obtained as early as possible and within 21 days of the onset of deafness. Specimen sources include whole clotted blood, stool, washings from throat or nasopharynx, cerebrospinal fluid, and fluid from the middle ear. Jaffe and Maassab, and others, identified adenovirus types I and III, Mycoplasma pneumoniae, and parainfluenza. About 60% of the patients with viral infections will recover spontaneously. No specific antiviral therapy exists.

5. Exploration of Middle Ear.

When the coagulation studies are normal and when there is a history of otologic trauma or physical exertion prior to the onset of sudden deafness, an exploration of the middle

15 ear is indicated to rule out a fistula of the oval window or round window leakage of perilymph from the inner ear. A plug of Gelfoam or fat may be used to seal the fistula.

6. Glycerin Test.

A new application of the glycerin test in the diagnosis of posttraumatic perilymph fistula was described by Lehrer et al. Temporary disappearance of abnormal responses to the fistula and Quix tests and improvement in the hearing occurred. The glycerin test was useful in confirming the diagnosis of posttraumatic fistula in 13 patients in whom fistulas were found at tympanotomy.

7. Medical Therapy.

When coagulation studies indicate accelerated coagulation, one should proceed with the medical therapy.

a. Ambulatory care: Vasodilating drugs such as nylidrin (Arlidin), nicotinic acid, and nicotinyl alcohol (Roniacol) have been used. Suga and Snow showed that nicotinic acid, even in massive doses, has no measurable effect on cochlear blood flow.

b. Hospitalization should include: (1) Bed rest; (2) Intravenous histamine given as 2.75 mg in 500 mL normal saline over 30 min daily for 3 days with careful monitoring of blood pressure and pulse every 5 minutes; (3) low-molecular-weight dextran (10%) given intravenously, 500 mL every 12 hours for 3 days; (4) heparin given to maintain a clotting time of two to three times normal.

c. Anticoagulants, steroids, and Urografin may be effective in some cases.

d. For idiopathic sudden sensorineural deafness, Meyerhoff suggests:

1) Hospitalization and bed rest.

2) Heparin 5000-10.000 units subcutaneously every 12 hours.

3) 40 units of adrenocorticotropic hormone (ACTH) IM each morning.

4) Low-molecular-weight dextran (10%) IV in 500 mL quantities over a 4-hour period; repeated every 12 hours.

5) Papaverine-hydrochloride (smooth muscle relaxant) orally 150 mg every 12 hours.

6) The above regimen is continued for 5 days. The progress is monitored with daily audiograms. If no improvement is seen, the patient is evaluated neuro-otologically. If the possibility of a perilymph fistula leak exists, tympanotomy is performed.

16 8. X-Ray Studies of Internal Auditory Canal.

When the audiometric studies indicate a retrocochlear loss, radiographic examination of the internal auditory canal should be performed (see Chap. 24).

9. Posterior Fossa Myelogram.

If the retrocochlear hearing loss does not recover and if the hearing loss is mild or moderate, one should perform a posterior fossa myelogram. If the posterior fossa myelogram is abnormal, acoustic neuroma is suggested and removal indicated. If the posterior fossa myelogram is normal the patient must be followed every 6 months with repeat audiograms, repeat posterior fossa myelogram, or repeat diagnostic labyrinthotomy.

10. Perilymph Tap (Diagnostic Labyrinthotomy).

Small acoustic neuromas produce an elevated protein content of the perilymph of the inner ear while cerebrospinal fluid protein levels remain normal. Because the diagnostic labyrinthotomy may produce a worsening of the hearing loss, it should not be used to evaluate a mild or moderate hearing loss.

For diagnostic labyrinthotomy, under local anesthesia, a tympanomeatal flap is created and the middle ear entered. The footplate of the stapes is identified, cleaned of mucosa, and all bleeding controlled with Adrenalin. Then a hole is made in the footplate and a capillary tube is placed into the vestibule of the inner ear and perilymph obtained. Analysis of the fluid will be diagnostic of an acoustic neuroma if the protein content is 1000 mg% or greater.

11. Removal of Acoustic Neuroma.

Three major approaches to the internal auditory canal are available: (a) translabyrinthine approach, (b) middle cranial fossa approach, and (c) combined suboccipital and translabyrinthine approach (see following section: Benign Tumors of the Ear).

The translabyrinthine approach destroys hearing so it is used only if severe or total deafness is present or if the discrimination is so poor as to produce a nonfunctioning ear. The middle cranial fossa approach is somewhat more complicated by intracranial complications but it is possible in some cases to remove the tumor, while preserving the hearing and facial nerve function.

Prognosis and Rehabilitation

1. Approximately one-third of patients have a return of normal hearing, one-third are left with a 40-60 dB speech reception threshold, and one-third have total loss of useful hearing.

2. Spontaneous recovery to normal hearing is more likely to occur if the deafness is not associated with severe vertigo and if the deafness initially is not total.

17 3. Once recovery of hearing begins, it usually takes place rapidly in a matter of a few days. The longer the delay between the onset of deafness and the onset of recovery, the worse the prognosis for complete recovery.

4. Children who do not recover spontaneously from a unilateral sudden deafness should have preferential seating in school. Adults should be advised of the availability of a CROS (contralateral routing of signals) hearing aid.

5. Those patients who do not recover serviceable hearing from bilateral sudden deafness should have speech reading and auditory training. A hearing aid should be tried and used when appropriate.

6. When sudden deafness develops in an only hearing ear, exploration of the middle ear is indicated to rule out a hidden oval or round window fistula.

7. Priapism (a painful penile erection) as an unusual complication of heparin therapy for sudden deafness is reported by Clark et al.

Therapeutic Protocols

Therapeutic protocols

Therapeutic protocols suggested by the National Registry for Idiopathic Sudden Deafness include:

Method A:

1. Bed rest for 3 days with barbiturate or phenothiazine sedation.

2. Atropine (only if begun within 4 hours of the onset of deafness): 0.75 mg IM or in 250 mL of 5% dextrose in water IC as a single dose.

3. Procaine: 0.2% in 250 mL of 5% dextrose in water IV twice daily for 3 days.

4. Diphenhydramine (Benadryl): 50 mg 4 times daily orally or by injection until the hearing has stabilized for at least 3 weeks.

5. Nylidrin (Arlidin): 6 mg orally four times daily until the hearing has stabilized for at least 3 weeks.

6. Ascorbic acid (vitamin C): 1000 mg in each IV of procaine.

18 Method B:

1. Bed rest for 3 days.

2. Histamine phosphate: 2.75 mg in 250 mL of 5% dextrose in water IC daily for 3 days. Adjust the rate to produce a flush bot not a headache. Do not run at the same time as dextran as this seems to produce a severe headache.

3. Dextran: 10% (Rheomacrodex), 500 mL every 12 hours for 3 days.

4. Nicotinic acid in a flushing dose (50-300 mg) before meals and at bedtime, until hearing has stabilized for at least 3 weeks. This is begun in the office when the patient is first seen.

Method C:

1. Hospitalization for at least 3 days.

2. Heparin: 200 mg (20.000 units) every 12 hours IM, IV, or subcutaneously to keep the Lee White clotting time between 15-20 minutes which is two to three times normal.

3. Warfarin (Coumadin) is begun on the secon day and then the heparin is discontinued when the prothrombin time is two and a half to three times normal. Anticoagulation is continued for 4 weeks. Medical consultation should be obtained to manage the heparin and Coumadin anticoagulation.

4. Procaine: 0.2% in 250 mL of 5% dextrose in water IV twice daily for 3 days.

Method D: Prednisone: 10 mg three times daily for 10 days, then in reducing amounts to nil over 10 days.

Method E: Exploratory tympanotomy to seal a perforated round or oval window.

Method F:

1. Bed rest for 3 days or until hearing and/or vertigo is stable.

2. No medication: It is possible that the previously recommended medications have no effect or even an adverse effect on the prognosis. This group would serve as a control.

Benign Tumors of the Ear

External Ear

Benign tumors of the auricle and the external auditory canal include angioma (capillary hemangioma, cavernous hemangioma and lymphangioma), dermoid tumors, cylindroma, melanoma, Winkler's disease, osteoma, exostosis, adenoma, ceruminoma, chondroma, lipoma, xanthoma, myoma, myxoma, mixed tumors of the salivary gland type, and keratosis obturans.

19 Osteoma

Osteoma (cancellous) occurs in the auditory canal as a single large pedunculated tumor near the lateral end of the bony portion on one side only. It arises from the region of either the tympanosquamous suture or the tympanomastoid suture. Hearing loss and discomfort are common symptoms.

Treatment. The treatment is surgical removal when symptomatic.

Exostosis

Exostoses (dense ivory compact bone) are the most common tumors of the external auditory canal. These are usually bilateral and asymptomatic unlewss accompanied by accumulation of debris against the tympanic membranes resulting in infection or obstruction. The causative factor most likely responsible is prolonged and repeated stimulation of the external auditory canal by cold water. Exostoses most commonly are seen in saltwater swimmers. Other factors which might play a role include chronic irritation from infection, eczema, and trauma.

Treatment. Treatment consists of surgical excision when symptomatic. Attempts to remove exostoses with a hammer and gauge may produce fractures in the surrounding bone, possibly resulting in facial palsy. Removal should be done with a small cutting burr. In some cases exostoses can be removed through a speculum, raising a flap of meatal skin by an incision external to the exostoses. In others, an endaural or postauricular incision is necessary.

Cerumenoma

This uncommon tumor is an adenoma of sweat gland origin and presents as a smooth intraverted polypoid swelling in the outer end of the meatus. This tumor may become malignant.

Treatment. Local recurrence after excision is common. Wide excision including a margin of healthy skin is advised.

Winkler's Disease

This is a rare, painful nodular growth of unknown origin occurring on top of the helix and mostly in men. It consists of tiny arteriovenous anastomosis with many nerve endings similar to a glomus body. The small nodule is painfully tender, preventing some patients from sleeping on the ear.

Treatment: Surgical excision or injection of cortisone for the relief of pain is the usual treatment.

Keratosis Obturans

This rare condition also is called cholesteatoma of the external auditory canal, and is characterized by an accumulation of large plugs of desquamating squamous epithelium

20 (cholesteatoma) deep within the external auditory canal. It is often associated with chronic pulmonary disease, sinusitis, and bronchiectasis. Pain is the common presenting symptom and results from erosion of the bony canal (destructive or invasive keratitis). Hearing loss is usual.

Etiology. The cause is unknown, but probably is due to faulty migration of squamous epithelial cells from the surface of the tympanic membrane and adjacent canal.

Treatment. This consists of periodic removal of accumulated debris. General anesthesia may be required.

Middle Ear

Benign tumors of the middle ear and mastoid include glomus jugulare tumor, osteoma, neurinoma of the seventh and eight cranial nerves, intratympanic meningioma, glioma, cylindroma, dermoid cysts, hemangioma, and acoustic neuroma.

Glomus Jugulare Tumor

This tumor is also called: chemodectoma, nonchromaffin paraganglioma, carotid body tumor, tympanic body tumor, and glomus tympanicum. Glomus jugulare tumor arises from the glomus bodies located in the adventitia of the dome of the jugular bulb or along branches of the tympanic plexus.

Pathology. Glomus jugulare tumors usually arise in the hypotympanum at the site of the entrance of Jacobson's nerve in the adventitia of the jugular bulb. In many instances they arise on the promontory. The incidence is five times more frequent in women than in men. The tumors consist of vascular sinuses supplied by the ascending pharyngeal artery which enters the tympanum along with Jacobsen's nerve. These tumors grow slowly but are progressively destructive by invasion into the surrounding structures. Instances of multicentric origin and association with carotid body tumors have been reported. The tumors occasionally metastasize to the lungs and cervical nodes.

Clinical Features. The earliest symptom is a pulsating tinnitus which is synchronous with the pulse. The hearing loss follows as the tumor enlarges. As it invades the tympanic membrane, spontaneous bleeding and discharge due to secondary infection will occur. Isolated facial paralysis frequently is present. Invasion along the course of the jugular wall results in multiple involvement of the ninth, tenth, eleventh, and twelfth cranial nerves. Invasion of the cochlea and petrous tip is a late occurence resulting in sensorineural hearing loss and (rarely) paralysis of the fifth and sixth cranial nerves.

Diagnosis. Examination in the early stages may reveal a reddish swelling behind the tympanic membrane which with magnification may be seen to pulsate. If the drumhead is dull and the tumor small, this appearance may be confused with Schwartze's sign in otosclerosis. As the tumor enlarges, it causes the inferior portion of the tympanic membrane to bulge and finally burst revealing a smooth large red polypoid mass which bleeds very easily (and often massively) on manipulation. Application of pressure with the pneumatic otoscope causes the tumor to increase in pulsation. As the pneumatic pressure is raised to exceed systolic pressure, a sudden blanching occurs (Brown's pulsation sign). Radiographic examination is of little

21 value in early cases but as the tumor advances will reveal the extent of bony destruction. In advanced tumors, external carotid angiography, polytomography, and retrograde jugularography are helpful in delineating the extent of tumor. The diagnosis is confirmed by biopsy which must be done carefully in the hospital because of the severe hemorrhage which may occur. With an intact tympanic membrane the biopsy is best done through a tympanotomy approach and combined with total excision.

Classification. Rosenwasser classified glomus tumors into three groups: group I include those cases in whom the tympanic membrane is intact and the lesion is small and confined to the middle ear; group II include those cases in whom the middle ear, aditus, antrum, and mastoid bone appear to be involved, and group III include those cases in whom there is a wide spread extension, at times with intracranial involvement.

Alford and Gilford classified the tumor into five stages:

Stage O: The earliest manifestation of a glomus tumor. The patient complains of hearing loss and/or pulsating tinnitus. There will be normal hearing or a conductive hearing loss. The drum head is intact but discolored. Radiographs will be normal.

Stage I: Aural discharge due to involvement of the tympanic membrane by the tumor is noted. Radiographs show clouding of the middle ear but no bone erosion. There is no cranial nerve involvement.

Stage II: Facial paralysis now present, and there is sensorineural hearing loss. Radiographs may show enlargement of the jugular forament but no bone erosion.

Stage III: Involvement of the jugular foramen with paralysis of the ninth, tenth, eleventh, and/or seventh cranial nerve. Radiographic evidence of erosion of the petrous bone and enlargement of the jugular foramen is noted.

Stage IV: Intracranial extension producing papilledema, extensive involvement of the petrous bone, and paralysis of the third, fourth, fifth, sixth, and seventh cranial nerves.

Treatment. Early cases may be cured by surgical excision but advanced cases should be treated with palliative radiation. The treatment may be summarized as follows:

Group I: Tumor involving the middle ear only (glomus tympanicum). Excision via:

1. Tympanotomy.

2. Endaural hypotympanotomy of Shambaugh.

3. Postauricular facial recess approach.

Group II: Tumor extending into the attic or mastoid: Radical mastoidectomy and hypotympanic resection (with ligation of ascending pharyngeal artery or external carotid artery) followed by radiation when removal was incomplete.

22 Group III: Tumor involving the jugular forament with cranial nerve paralysis:

1. Partial excision with radiation.

2. Combined radical mastoid and hypotympanic neck dissection.

3. Temporal bone resection with dissection and ligation of lateral sinus and jugular vein.

4. Modified infratemporal fossa approach.

Radiation often is used especially when complete removal is not possible. Tumor doses of 2400 to 6000 rad are given over a period of 2-4 weeks. Palliative benefit from radiotherapy is probably due to reduction in vascularity as the tumor cells are not considered to be radiosensitive.

Internal Ear

Acoustic Neuroma

Acoustic neuroma accounts for 78% of all tumors of the cerebellopontine angle. It is found in about 8% of all intracranial tumors and constitutes even a greater percentage of all posterior fossa lesions. The tumor most often becomes symptomatic between the ages of 30- 40 years. Routine autopsies have revealed a 2.4% incidence of asymptomatic acoustic neuroma. It is more common in females in a ratio of 3:2.

Pathology. Acoustic neuroma is a benign encapsulated tumor arising from the sheath of Schwann (neurilemma) of the eight nerve. The usual site of lesion is the vestibular portion of the nerve in the region of Scarpa's ganglion. The incidence of involvement of vestibular and auditory nerves is a 2:1 ratio. The eight nerve loses the neurilemmal sheath at the porus acousticus, and hence it is unlikely that the tumor would arise proximal to the porus. It usually begins in the internal auditory canal, slowly enlarges within the canal and with some degree of erosion extends toward the cerebellopontine angle. It is usually unilateral, but bilateral lesions may be noted as in the case of von Recklinghausen's disease. The size of the tumor may reach 5.0 cm although the more common size outside the canal is about 2.5-3.0 cm.

Histologically, the tumor is characterized by streams of elongated spindle cells, with the elongated nuclei often arrayed in a palisade pattern. Tumors in which there is a thick concentration of cells are called Antoni type A, whereas those in which the cells are loose are called Antoni type B.

23 Clinical Features

They include:

1. The earliest symptoms are tinnitus and unilateral progressive hearing impairment. In the early stages of acoustic neuroma, dizziness also is an extremely common complaint, appearing in the form of unsteadiness in about 83% of the patients.

2. Vertigo is not common initially, but may become a more prominent symptom with continued growth of the tumor.

3. Other early complaints are a sensation of prickling and itching, and pain in the ear.

4. Late manifestation of the disease develop from great pressure upon the auditory canal and extension of tumor into the posterior cranial fossa. The sensory part of the fifth nerve may become involved first, producing unilateral numbness of the face. The motor part of the seventh nerve may be affected, causing facial weakness. Eventually the cerebellum may be disturbed, producing slurring of speech, ataxia, and incoordination of one or both upper extremities. With continued growth the tumor can obstruct the flow of cerebrospinal fluid, creating an internal hydrocephalus. Headache, nausea, vomiting, and dullness of mental faculties may accompany these complications.

Diagnosis. Any patient suspected of acoustic neuroma should undergo a complete audiologic, vestibular, and neurologic evaluation.

Audiometric Examination. The audiometric examination indicates that:

1. All the patients have sensorineural hearing loss. Approximately 64% have a high- tone loss, but others can present with a flat-type curve.

2. Impairment of speech discrimination is much greater than would be expected from pure tone loss. Discrimination scores of 0-30% occur in over half of the patients.

3. The short increments sensitivity index (SISI score) is in the region of 0-35% with retrocochlear lesions.

4. Approximately 50-60% of the patients with acoustin tumors show type III and type IV Bekesy tracings.

Brain Stem Evoked Response Audiometry. Recent studies with the early part of the evoked response, presumably from the brain stem, indicate that pressure on the auditory nerve from tumors can cause an increase in latency or the elimination of early response waves. The waves found as a result of the click stimulus are best compared by evaluating the P-5 wave latency from two ears.

The between-the-ears (intra-auricular) latency is usually less than 0.2 msec, and is found to be 0.4 msec or greater for acoustic tumor cases. In 21/35 acoustic neuroma Selters

24 and Brackmann reported that the P wave was completely absent. The intra-auricular latency difference was positive in 91% of these cases and measured from 0.4-3.2 msec.

In four patients the intra-auricular difference was less than 0.2 msec, but one of these patients had bilateral acoustic tumors. It was proposed that in the other three cases, intra- auricular latency was normal because of insufficient pressure on the cochlear nerve.

Although false-positive findings may occur in patients with severe (greater than 75 dB) hearing losses, the study is a most valuable noninvasive test to be added to the battery of tests used in the detection of acoustic neuromas when the hearing threshold is less than 70 dB.

Vestibular Examination. Diminished or absent response to caloric testing is an important and early sign of acoustic tumor. About 96% of patients with acoustic neuroma have an abnormal caloric response. Electronystagmography may show spontaneous nystagmus away from the side of the lesion. In some patients positional nystagmus may be noted. Vertical nystagmus may suggest posterior fossa involvement.

Neurologic examination. With an increase in intracranial pressure there may be blurred optic discs, impairment of occular motor function, diminished sensation of the face, and facial weakness. Hitselberger and House noted hypesthesia of the posterior wall of the external auditory canal (Hitselberger's sign). Lacrimation, taste, and blink reflexes should be tested. A complete neurological examination should be a must in all suspected cases of acoustic neuroma.

Radiologic Evaluation (also see Chap. 24 Radiology)

1. The radiologic examination for an acoustic tumor usually includes conventional films, polytomography, computed tomography, posterior fossa myelogram, and arteriography.

2. The x-rays that are most valuable in evaluation of the internal auditory canal are Stenvers, transorbital, Towne's, and submentovertical projections. These views demonstrate enlargement of the canal or erosion of the petrous portion of the temporal bone in about 85% of the patients.

3. Computed tomography provides an excellent screening technique permitting diagnosis of acoustic neuromas over 2 cm in size when the examination is carried out with contrast enhancement. Since acoustic neuromas have tissue densities equal to those of the surrounding brain, enhancement with contrast is necessary to produce increases in density and well-circumscribed margins. All tumors over 2 cm in diameter usually are shown with contrast enhancement. The 20% false-negative studies may occur in patients with tumor sizes less than 2 cm.

4. When the screening studies such as conventional film and polytomography are positive and agree with the clinical and audiometric examinations, a CT scan then should be performed. If the latter is negative, Pantopaque myelography or air-CT should follow.

5. The decision to proceed to an invasive radiologic study for a small tumor recently has been based on results from brain stem evoked audiometry (BSEA). When BSEA is

25 negative together with other audiometric studies, then invasive radiologic studies are not indicated.

6. A positive BSEA test indicating a retrocochlear lesion and combined with a negative CT scan should be followed by posterior fossa myelography or cisternography combined with CT.

7. It has become clear that the conventional CT scan cannot detect acoustic tumors in the cerebellopontine angle (CPA) that are less than 1.5 cm in size, or tumors that lie wholly within the internal auditory canal (IAC).

8. Posterior fossa myelography with Pantopaque remains the best diagnostic procedure for the small acoustic tumor (90-100% accuracy).

Laboratory Examination. In acoustic neuroma:

1. Cerebrospinal fluid examination shows elevated protein more often than in any other intracranial tumor.

2. A radioisotope brain scan may show a high incidence (85%) of positive scan.

3. Diagnostic labyrinthotomy: Small acoustic neuromas produce an elevated content of the perilymph of the inner ear in the presence of a normal content of the cerebrospinal fluid. Through a tympanotomy approach, a small hole is made in the footplate and a capillary tube is placed into the vestibule and the perilymph is obtained. A protein content of 1000 mg% or higher is diagnostic of an acoustic neuroma.

Differential Diagnosis. The following conditions may be confused with acoustic neuroma:

1. Endolymphatic hydrops is most easily and frequently confused with acoustic neuroma. Clinical history, further radiologic and laboratory tests will help to differentiate these lesions.

2. Cystic arachnoiditis of the cerebellopontine angle from previous acute or chronic otitis media producing otitic hydrocephalus may stimulate an acoustic neuroma. The history of otorrhea is important.

3. Meningioma arising from the posterior surface of the petrous pyramid produces the angle syndrome. Involvement of other cranial nerves generally occur earlier in meningioma, and loss of hearing and vestibular response occur later than in acoustic neuroma. The spinal fluid protein is generally not elevated in meningioma. Radiologic studies show hyperostosis, calcification, or destruction of the petrous pyramid, or an increased vascularity on angiography.

4. Congenital cholesteatoma of the petrous pyramid may produce the angle syndrome. Facial nerve paralysis occurs earlier than in acoustic neuroma and the x-ray changes are characteristic.

26 5. Multiple sclerosis may stimulate an angle tumor except for its characteristic remissions. Spinal fluid protein is not greatly elevated in multiple sclerosis.

Surgical Treatment. A classification of patients and a system of management on the surgical removal of acoustic tumors were suggested by Pulec et al and summarized as shown in Table 8-1.

Table 8-1. Classification and Surgical Management of Acoustic Neuromas

Site of Tumor ==> Associated Conditions ==> Management

Intracanalicular tumor (up to 8 mm diameter) ==> Some hearing ==> Removal via middle cranial fossa approach (facial nerve preserved and hearing can be saved in 60% of cases)

Intracanalicular tumor ==> No hearing ==> Translabyrinthine approach

Medium-sized tumor (2.5 cm in diameter) ==> With or without fifth nerve sign but no increased intracranial pressure, no papilledema, no cerebellar or long tract signs ==> Translabyrinthine approach

Large tumor (2.5 cm or more in diameter) ==> Increased intracranial pressure, fifth nerve signs, papilledema, cerebellar and long tract signs, headache, depressed mental ability ==> Suboccipital decompression with removal of occipital bone from the midline to the sigmoid sinus; removal of arch of the atlas, incision of the atlantooccipital ligament without opening the dura, followed in 5-7 days by translabyrinthine approach for removal of tumor.

Bilateral medium or large tumor ==> Useful hearing ==> Retrolabyrinthine approach with preservation of labyrinth and endolymphatic sac and removal of major portion of tumor leaving only small part over the sevent and eight nerves and internal auditory artery. Purpose: (1) preserve hearing, (2) relieve the life-threatening tumor mass. Repeat surgery when and if indicated.

Small, medium, or large tumor ==> High-risk case with disabling symptoms of vertigo, nausea, and ataxia ==> Translabyrinthine approach: to accomplish labyrinthectomy and brief subtotal removal of tumor.

27 The argon laser has been used routinely for acoustic tumor surgery by Glasscock et al. It has been used to vaporize and cut tissue and for photocoagulation in conjunction with a variety of surgical approaches to the cerebellopontine angle.

Tumor-Like Conditions of the Temporal Bone

Histiocytosis X (Reticuloendotheliosis)

The characteristics of the three clinical syndrome or variants of histiocytosis X (all involving the skin, skeleton, and reticuloendothelial system) may be summarized as follows.

Letterer-Siwe disease. This is a rare and rapidly fatal form of acute disseminated histiocytosis occurring in children before the age of 2 years, and characterized by fever, splenomegaly, hepatomegaly, lymphadenopathy, skeletal lesions, purplish skin rash, and anemia.

Hand-Schüller-Christian disease. This is a less severe and more chronic form in children and young adults, characterized by exophthalmos and diabetes insipidus from involvement of the sphenoid bone. When the temporal bone is affected, it may involve the mastoid cortex, the external auditory canal, labyrinth, the facial nerve, and the jugular foramen.

The characteristic histologic feature is the presence of lipoid-filled histiocytes (foam cells).

Treatment: Irradiation. The mortality is 30%.

Eosinophilic Granuloma. This is a less acute condition occuring in children and young adults, characterized by osteolytic lesions in one or several bone areas and a predilection for the frontal or temporal bone.

Otologic manifestations include swelling over the mastoid, granulations in the external auditory canal, otorrhea, deafness, and facial paralysis.

Histologically, the lesion presents two types of cells: (1) large, pale mononuclear histiocytes with mitotic figures, and (2) eosinophils.

Treatment is: (1) surgical excision or curettage of individual lesions; (2) radiotherapy for recurrences and inaccessible lesions. Useful for relief of pain.

Fibrous Dysplasia (Osteitis Fibrosa Cystica)

Fibrous dysplasia may involve a single bone (monostotic type), or, less often, several bones (polyostotic type). Fibrous dysplasia of bone usually first becomes manifest during childhood or early adult life and the lesions grow slowly. The polyostotic type characteristically involves the long bones and rarely the skull. The monostotic type may occur in the long bones, facial bones, or membranous bones. Occasionally the polyostotic type of fibrous dysplasia occurs in a form known as Albright's syndrome which is characterized by

28 multiple involvement of the long bones, pigmentation of the skin, and precocious puberty in females.

Fibrous dysplasia of the temporal bone manifests itself as a painless swelling in the region of the mastoid and the external auditory canal. Conductive hearing loss due to occlusion of the external auditory canal may be the only symptom.

Histologically, fibrous dysplasia is characterized by replacement of marrow with fibrous tissue containing spicules of bone undergoing resorption and formation. Active osteoblastic and osteoclastic activity usually is present and islands of cartilage may be seen.

Fibrous dysplasia has a female sex predominance in a ratio of 3:1. The onset is usually in childhood, and the lesions, when multiple, are often unilateral.

Differential diagnoses include hyperparathyroidism, Ollier's enchondromatosis, von Recklinghausen's disease, Paget's disease, Hand-Schüller-Christian disease, and other bone tumors. The history of painless swelling associated with the characteristic radiographic appearance (a typical loss of cellular structure and increased radiolucency due to replacement of osseous substance by fibrous tissue), and biopsy are adequate to differentiate fibrous dysplasia from these conditions.

Treatment of fibrous dysplasia is surgical excision. Radiotherapy appears to have a predisposing propensity to malignant degeneration and is considered as contraindicated for treatment of fibrous dysplasia.

Presbyacusis

This can be classified under the following subheadings:

Sensory

1. Atrophy of the organ of Corti and the auditory nerve in the basal end of the cochlea. Characterized by abrupt high-frequency loss.

2. Begins at middle age and is slowly progressive.

Neural

1. Loss of ganglion cells and degeneration of nerve fibers.

2. Significant disability in discrimination of speech.

3. Occurs late in life.

29 Metabolic

1. Stria atrophy.

2. Good discrimination.

3. Flat audiometric curve.

Mechanical

1. Descending audiometric curve. The basal turn is most involved.

2. Questionable stiffening of basilar membrane.

Miscellaneous

1. Seventy-five percent of ganglion cells can be missing and yet pure tone thresholds are maintained.

2. Loss of spiral ganglion cells does not necessarily produce hair cell degeneration.

3. Loss of hair cells with normal supporting cells does not produce spiral ganglion cell degeneration.

4. The stria vascuularis is the source of +80 mv DC potential of the scala media.

30 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 9: Congenital Deafness

General Information

1. One person in eight carries a recessive gene for deafness; 1:4000 live births has hereditary deafness.

2. One percent of hereditary hearing loss is sex-linked; 9% are due to an autosomal- dominant inheritance; and 90% are the result of an autosomal-recessive transmission. Hereditary deafness consitutes 15% of all congenital deagness.

3. Dominant hearing loss usually progresses while the recessive type is nonprogressive.

4. Hereditary deafness can be classified as follows:

a. Hereditary (congenital) deafness without associated abnormalities (autosomal- dominant, autosomal-recessive, or sex-linked).

b. Hereditary congenital deafness associated with integumentary system disease (autosomal-dominant, autosomal recessive, or sex-linked).

c. Hereditary congenital deafness associated with skeletal disease (autosomal-dominant, autosomal recessive, or sex-linked).

d. Hereditary congenital deafness associated with other abnormalities (autosomal- dominant, autosomal recessive, or sex-linked).

Each category can be subdivided along three kinds of hearing impairment: sensorineural, conductive, and mixed.

5. Otologists have attempted to classify inner ear developmental anomalies. One of the classifications is:

a. Michel: Complete failure of developmental of the inner ear (bony and membranous aplasia). The middle ear and external auditory canal may be normal.

b. Mondini-Alexander: Incomplete development of the bony and membranous labyrinth. The cochlea may be represented by a single curved tube, and the vestibular labyrinth is not developed.

c. Scheibe: Membranous cochlea-saccular aplasia (pars inferior). The bony labyrinth is normal. The utriculus and semicircular canals (pars superior) are normal.

d. Alexander: Partial aplasia of the cochlear duct giving rise to high-frequency hearing loss.

1 e. Bing-Siebenmann: The membranous vestibular apparatus is maldeveloped. The membranous cochlea may or may not be normal.

6. The Scheibe's type of inner ear anomaly is the most commonly encountered. It is believed to be transmitted autosomal recessively. The next most common is the Mondini- Alexander type which is believed to be autosomal dominant.

7. The rubella syndrome includes congenital cataract, cardiovascular anomalies, mental retardation, retinitis, and deafness. It has been reported that 5-10% of the mothers with rubella in the first trimester gave birth to children with deafness. Alford reported 90/141 rubella syndrome children presented with deafness. The eye is the most commonly affected organ followed by the ears and then by the heart. Histologically, the middle ear as well as inner ear anomalies have been described. Confirmatory tests for the rubella syndrome include identification of fluorescent antibody, serum hemagglutination, and viral cultures from stool and throat. Deafness of a viral etiology shows: (a) degeneration of the organ of Corti; (b) adhesions between the organ of Corti and Reissner's membrane; (c) rolled up tectorial membrane; (d) partial or complete stria atrophy; and (e) scattered degeneration of neural elements (cochlea-saccule degeneration).

8. Twenty percent of the kernicterus babies will have severe deafness secondary to damage to the dorsal and ventral cochlear nuclei as well as the superior and inferior colliculi nuclei. Clinically, bilateral sensorineural loss especially in high frequencies is manifested. The most accepted indication for exchange transfusion is a serum bilirubin of greater than 20 mg/100 mL.

9. Syphilitic deafness: Tamari and Itkin estimated that hearing loss occured in:

17% of early congenital syphilis 18% of late congenital syphilis 25% of late latent syphilis 29% of asymptomatic neurosyphilis 80% of symptomatic neurosyphilis.

Congenital

Contrary to the above, Karmody and Schuknecht reported 25-38% of patients with congenital syphilis had hearing loss. There exist two forms of congenital syphilis: early (infantile) and late (tardive). The infantile form is often severe, bilateral. These children usually have multisystem involvement and hence a fatal outcome.

Late congenital syphilis has progressive hearing loss of varying severity and time of onset. Hearing losses that have the onset in early childhood are usually bilateral, sudden, severe, and associated with vestibular symptoms. The symptom complex is similar to Ménière's disease. The late onset form (sometimes as late as the fifth decade of life) has mild hearing loss. Karmody and Schuknecht also pointed out that the vestibular disorders of severe episodic vertigo are more common in the late-onset group than in the infantile group. Histopathologically, osteitis with mononuclear leukocytosis, obliterative endoarteritis, and endolymphatic hydrops is noticed. Serum and CSF serology may or may not be positive.

2 Treatment with steroids and penicillin seems to be of benefit. Other sites of congenital syphilis are:

a. Nasal cartilaginous and bony framework.

b. Periostitis of the cranial bones (bossing).

c. Periostitis of the tibia (saber shin).

d. Injury to the odontogenous tissues (Hutchinson's teeth).

e. Injury to the epiphyseal cartilages (short stature).

f. Commonly interstitial keratitis (cloudy cornea).

Two signs are associated with congenital syphilis:

a. Hennebert's sign consist of a positive fistula test without clinical evidence of middle ear or mastoid disease or a fistula. Nadol postulated that the vestibular stimulation is mediated by fibrous bands between the footplate and the vestibular membranous labyrinth. He observed that Hennebert's sign also may be present in Ménière's disease. The other explanatin was that the vestibular response is due to an excessive mobile footplate. The nystagmus in Hennebert's sign usually is more marked upon application of a negative pressure (see under Hennevert's Sign, Chap. 23: Syndromes and Eponyms).

b. Tullio's phenomenon consists of vertigo and nystagmus on stimulation with high- intensity sound such as the Barany noise box. This phenomenon occurs not only in congenital syphilis patients with a semicircular canal fistula but also in postfenestration patients if the footplate is mobile and the fenestrum patent. It also can be demonstrated in chronic otitis media should the patient have an intact tympanic membrane, ossicular chain, and a fistula - a rare combination.

For Tullio's phenomenon to take place, a fistula of the semicircular canal and intact sound transmission mechanism to the inner ear (i.e. intact tympanic membrane, intact ossicular chain, mobile footplate) must be present. The pathophysiology is that the high- intensity noise energy transmitted through the footoplate finds the course of least resistance and displaces toward the fistula instead of toward the round window membrane.

Acquired

Hearing loss may occur in the secondary or tertiary forms of acquired syphilis. Histopathologically, osteitis with round cell infiltration is noticed. In tertiary syphilis, gummatous lesions may involve the auricle, mastoid, middle ear, and petrous pyramid. These lesions can cause a mixed hearing loss. Since penicillin and other antibiotic therapy is quite effective in treating acquired syphilis, this form of deafness is rare nowadays.

10. Cretinism: Retarded growth, mental retardation and mixed hearing loss, are seen in this condition.

3 I. Hereditary Deafness Without Associated Abnormalities

A. Stria Atrophy (hereditary, not congenital).

1. Autosomal dominant. 2. The sensorineural hearing loss begins at middle-age and is progressive. 3. Good discrimination is maintained. 4. Flat audiometric curve. 5. Positive SISI test. 6. Bilaterally symmetrically hearing loss. 7. The patient never becomes profoundly deaf.

B. Otosclerosis (hereditary, not congenital).

1. See Chap. 8.

II. Hereditary Congenital Deafness Associated With Integumentary System Disease

A. Albinism with Blue Irides.

1. Autosomal dominant or recessive. 2. Sensorineural hearing loss.

B. Ectodermal Dysplasia, Hidrotic (Anhidrotic ectodermal dysplasia is sex-linked recessive. Mixed or conductive hearing loss).

1. Autosomal dominant. 2. Small dystrophic nails. 3. Coniform teeth. 4. Elevated sweat electrolytes. 5. Sensorineural hearing loss.

C. Forney's Syndrome.

1. Autosomal dominant. 2. Lentigines. 3. Mitral insufficiency. 4. Skeletal malformations. 5. Conductive hearing loss.

D. Lentigines.

1. Autosomal dominant. 2. Brown's spots appear on the skin. These begin to appear at age 2. 3. Ocular hypertelorism. 4. Pulmonary stenosis. 5. Abnormalities of the genitalia. 6. Retarded growth.

4 7. Sensorineural hearing loss.

E. Leopard Syndrome.

1. Autosomal dominant with variable penetrance. 2. Variable sensorineural hearing loss. 3. Ocular hypertelorism. 4. Pulmonary stenosis. 5. Hypogonadism. 6. ECG changes with widened QRS or bundle branch block. 7. Retardation of growth. 8. Normal vestibular apparatus. 9. Lenitigines. 10. Skin changes progressive over the first and second decades.

F. Piebaldness.

1. Sex-linked or autosomal recessive. 2. Blue irides. 3. Fine retinal pigmentation. 4. Depigmentation of scalp, hair, and face. 5. Areas of depigmentation on limbs and trunk. 6. Sensorineural hearing loss.

G. Tietz's Syndrome.

1. Autosomal dominant. 2. Profound deafness. 3. Albinism. 4. Eyebrows absent. 5. Blue irides. 6. No photophobia or nystagmus.

H. Waardenburg's Disease.

1. Autosomal dominant with variable penetrance. 2. Contributes 1-7% of all hereditary deafness. 3. Widely spaced medial canthi. This is present in all cases. 4. Flat nasal root in 75% of the cases. 5. Confluent eyebrow. 6. Sensorineural hearing loss (unilateral or bilateral). Hearing loss is present in 20% of cases. 7. Colored irides. 8. White forelock. 9. 10% of these patients have areas of depigmentation. 10. Abnormal tyrosine metabolism. 11. 75% of these patients have diminished vestibular function. 12. 10% of these patients are associated with cleft lip and palate.

5 III. Hereditary Congenital Deafness Associated With Skeletal Disease

A. Achondroplasia.

1. Autosomal dominant. 2. Large head, short extremities. 3. Dwarfism. 4. Mixed hearing loss (fused ossicles). 5. Saddle nose, frontal and mandibular prominence.

B. Apert's Disease (Acrocephalosyndactyly).

1. Autosomal dominant. 2. Syndactylia. 3. Flat conductive hearing loss secondary to stapes fixation. 4. Patent cochlear aqueduct has been noted histologically. 5. Frontal prominence, exophatlmos. 6. Craniofacial dysostosis, hypoplastic maxilla. 7. Proptosis, saddle nose, high arched palate, and occasionally, with spina bifida. 8. Occurs in about 1:150.000 live births.

C. Atresia Auris Congenita.

1. Autosomal dominant. 2. Unilateral or bilateral involvement are possible. 3. Middle ear abnormalities with VII nerve anomaly. 4. Internal hydrocephalus. 5. Mental retardation. 6. Epilepsy. 7. Choanal atresia and cleft palate.

D. Cleidocranial Dysostosis.

1. Autosomal dominant. 2. Absent or hypoplastic clavicle. 3. Failure of fontanelles to close. 4. Sensorineural hearing loss.

E. Crouzon's Disease (Craniofacial Dysostosis).

1. Autosomal dominant. 2. One-third of the cases are associated with hearing loss. 3. Mixed hearing loss in some cases. 4. Cranial synostosis. 5. Exophthalmos and divergent squint. 6. Parrot-beaked nose. 7. Short upper lip. 8. Mandibular prognathism and small maxilla.

6 9. Hypertelorism. 10. The external auditory canal may be atretic. 11. Congenital enlargement of the sphenoid bone. 12. Premature closure of the cranial suture lines can lead to mental retardation.

F. Engelmann's Syndrome (Diaphyseal Dysplasia).

1. Autosomal dominant; ? recessive. 2. Progressive mixed hearing loss. 3. Progressive cortical thickening of diaphyseal regions of long bones and skull.

G. Hand-Hearing Syndrome.

1. Autosomal dominant. 2. Congenital flexion contractures of fingers and toes. 3. Sensorineural hearing loss.

H. Klippel-Feil (Brevicollis; Wilderevanck's) Syndrome.

1. Autosomal recessive or dominant. 2. The incidence in females if greater than in males. 3. Sensorineural hearing loss along with middle ear anomalies. 4. Short neck due to fused cervical vertebrae. 5. Spina bifida. 6. External auditory canal atresia.

I. Madelung's Deformity (Related to Dyschondrosteosis of Leri-Weill).

1. Autosomal dominant. 2. Short stature. 3. Ulna and elbow dislocation. 4. Conductive hearing loss secondary to ossicular malformation with normal tympanic membrane and external auditory canal. 5. Spina bifida occulta. 6. The ratio of female to male is 4:1.

J. Marfan's Syndrome (Arachnodactyly, Ectopia Lentis, Deafness).

1. Autosomal dominant. 2. Thin elongated individuals with long spidery fingers. 3. Scoliosis. 4. Hammer toes. 5. Mixed hearing loss.

7 K. Mohr's Syndrome (Oral-Facial-Digital Syndrome II).

1. Autosomal recessive. 2. Conductive hearing loss. 3. Cleft lip, high-arched palate. 4. Lobulated nodular tongue. 5. Broad nasal root, bifid tip of nose. 6. Hypoplasia of the body of the mandible. 7. Polydactyly and syndactyly.

L. Osteopetrosis (Albers-Schönberg Disease; Marble Bone Disease).

1. Autosomal recessive (A rare dominant transmission has been reported). 2. Conductive or mixed hearing loss. 3. Fluctuating facial nerve paralysis. 4. Sclerotic, brittle bone due to failure of resorption of calcified cartilage. 5. Cranial nerves II, V, VII also may be involved. 6. Optic atrophy. 7. Atresia of paranasal sinuses. 8. Choanal atresia. 9. Increased incidence of osteomyelitis. 10. The widespread form of this disease may lead to obliteration of the bone marrow, severe anemia, and rapid demise. 11. May have hepatosplenomegaly.

M. Oto-Facial-Cervical Syndrome.

1. Ausomal dominant. 2. Depressed nasal root. 3. Protruding narrow nose. 4. Narrow elongated face. 5. Flattened maxilla and zygoma. 6. Prominent ears. 7. Preauricular fistulas. 8. Poorly developed neck muscles. 9. Conductive hearing loss.

N. Oto-Palatal-Digital Syndrome.

1. Autosomal recessive. 2. Conductive hearing loss. 3. Mild dwarfism. 4. Cleft palate. 5. Mental retardation. 6. Broad nasal root, hypertelorism. 7. Frontal and occipital bossing. 8. Small mandible. 9. Stubby, clubbed digits.

8 10. Low-set small ears. 11. Winged scapulae. 12. Malar flattening. 13. Downward obliquity of eye. 14. Down-turned mouth.

O. Paget's Disease (Osteitis Deformans).

1. Autosomal dominant with variable penetrance. 2. Mainly sensorineural hearing loss but mixed hearing loss is seen as well. 3. Occasionally may develop cranial nerve involvement. 4. Onset usually at middle-age, involving skull and long bones of the legs. 5. The endochondral bone is somewhat resistant to this disease.

P. Pierre Robin Syndrome (Cleft Palate, Micrognathia, and Glossoptosis).

1. Autosomal dominant with variable penetrance; possibly not hereditary but due to intrauterine insult. 2. It occurs in 1:30.000 to 1:50.000 live births. 3. Glossoptosis. 4. Micrognathia. 5. Cleft palate (in 50% of the cases). 6. Mixed hearing loss. 7. Malformed auricles. 8. Mental retardation. 9. Hypoplastic mandible. 10. Möbius' syndrome. 11. Subglottic stenosis not uncommon. 12. Aspiration a common cause of death.

Q. Pyle's Disease (Craniometaphyseal Dysplasia).

1. Autosomal dominant (less often autosomal recessive). 2. Conductive hearing loss can begin at any age. It is progressive, and it is secondary to fixation of the stapes or other ossicular abnormalities. Mixed hearing loss is also possible. 3. Cranial nerve palsy secondary to narrowing of the foramen. 4. Splayed appearance of long bones. 5. Choanal atresia. 6. Prognathism. 7. Optic atrophy. 8. Obstruction of sinuses and nasolacrimal duct.

R. Roaf's Syndrome.

1. Not hereditary. 2. Retinal detachment, cataracts, myopia, coxavara, kyphoscoliosis, and retardation. 3. Progressive sensorineural hearing loss.

9 S. Dominant Proximal Symphalangia and Hearing Loss.

1. Autosomal dominant. 2. Ankylosis of proximal interphalangeal joint. 3. Conductive hearing loss early in life.

T. Treacher Collins Disease (Mandibulofacial Dysostosis; Franceschetti-Zwahlen-Klein Syndrome).

1. Autosomal dominant or intrauterine abuse. 2. Antimongoloid palpebral fissures with notched lower lids. 3. Malformation of ossicles (stapes is usually normal). 4. Auricular deformity, atresia of external auditory canal. 5. Conductive hearing loss. 6. Preauricular fistulas. 7. Mandibular hypoplasia and malar hypoplasia. 8. "Fish-mouth". 9. Normal IQ. 10. Usually bilateral involvement. 11. May have cleft palate and cleft lip. 12. Arrest in embryonic development occurs at 6-8 weeks to give the above findings.

U. Van Buchem's Disease (Hyperostosis Corticalis Generalisata).

1. Autosomal recessive. 2. Generalized osteosclerotic overgrowth of skeleton including skull, mandible, ribs, long and short bones. 3. Cranial nerve palsies due to obstruction of the foramina. 4. Increased serum alkaline phosphatase. 5. Progressive sensorineural hearing loss.

V. Van der Hoeve's Syndrome (Osteogenesis Imperfecta).

1. Autosomal dominant with variable expressivity. 2. Fragile bones, loose ligaments. 3. Blue or clear sclera, triangular facies, dentinogenesis imperfecta. 4. 60% of osteogenesis imperfecta patients have blue sclera and hearing loss which are most frequently noticed after age 20. The hearing loss is conductive and is due to stapes fixation by otosclerosis. Hearing loss also can be due to ossicular fracture. Some use the term Van der Hoeve's syndrome to describe osteogenesis imperfecta with otosclerosis. Others use the term interchangeably with osteogenesis imperfecta regardless of whether otosclerosis is present or not. 5. The basic pathologic defect is "abnormal osteoblastic activity". 6. When operating on such a patient, it is important to avoid fracture of the tympanic ring or the long process of the incus. It is also important to realize that the stapes footplate may be "floating". 7. The sclera may have increased mucopolysaccharide content.

10 8. These patients have normal calcium, phosphorus, and alkaline phosphatase in the serum. 9. Occasionally capillary fragility is noticed in these patients.

IV. Hereditary Congenital Deafness Associated With Other Abnormalities

A. Acoustic Neurinomas (Inherited).

1. Autosomal dominant. 2. Progressive sensorineural hearing loss in the second or third decades of life. 3. Ataxia, visual loss. 4. No cafe au lait spots.

B. Alport's Disease.

1. Autosomal dominant. 2. Progressive nephritis and sensorineural hearing loss. 3. Hematuria, proteinuria beginning the first or second decade of life. 4. Males with this disease usually die of uremia by the age of 30. Females are less severely affected. 5. Kidneys are affected by chronic glomerulonephritis with interstitial lymphocytic infiltrate and foam cells. 6. Progressive sensorineural hearing loss begins at age 10. Although it is considered not sex-linked, hearing loss affects almost all males but not all females. Histologically, degeneration of the organ of Corti and stria vascularis is observed. 7. Spherophalera cataract. 8. Hypofunction of the vestibular organ. 9. Contributes 1% of hereditary deafness.

C. Alstrom's Disease.

1. Autosomal recessive. 2. Retinal degeneration giving rise to visual loss. 3. Diabetes, obesity. 4. Progressive sensorineural hearing loss.

D. Cockayne's Syndrome.

1. Autosomal recessive. 2. Dwarfism. 3. Mental retardation. 4. Retinal atrophy. 5. Motor disturbances. 6. Progressive hearing loss bilaterally.

11 E. Congenital Cretinism (To be distinguished from Pendred's Syndrome).

1. 35% of the patients with congenital cretinism present with congenital hearing loss of the mixed type (irreversible). 2. Goiter, hypothyroid. 3. Mental and physical retardation. 4. Abnormal development of the petrous pyramid. 5. This disease is not inherited in a specific Mendelian manner. It is restricted to a certain geographical locale where a dietary deficiency exists.

F. Duane's Syndrome.

1. Autosomal dominant (some sex-linked recessive). 2. Inability to abduct eyes, retract globe. 3. Narrowing of palpebral fissure. 4. Torticolis. 5. Cervical rib. 6. Conductive hearing loss.

G. Fanconi's Anemia Syndrome.

1. Autosomal recessive. 2. Absent or deformed thumb. 3. Other skeletal, heart, and kidney malformations. 4. Increased skin pigmentation. 5. Mental retardation. 6. Pancytopenia. 7. Conductive hearing loss.

H. Fehr's Corneal Dystrophy.

1. Autosomal recessive. 2. Progressive visual and sensorineural hearing loss.

I. Flynn-Aird Syndrome.

1. Autosomal dominant. 2. Progressive myopia, cataracts, retinitis pigmentosa. 3. Progressive sensorineural hearing loss. 4. Ataxia. 5. Shooting pains in the joints.

J. Friedreich's Ataxia.

1. Autosomal recessive. 2. Childhood onset of nystagmus, ataxia, optic atrophy, hyperreflexia, and sensorineural hearing loss.

12 K. Goldenhar's Syndrome.

1. Autosomal recessive. 2. Epibulbar dermoids. 3. Preauricular appendages. 4. Fusion or absence of cervical vertebrae. 5. Colobomas of the eye. 6. Conductive hearing loss.

L. Hallgren's Syndrome.

1. Autosomal recessive. 2. Retinitis pigmentosa. 3. Progressive ataxia. 4. Mental retardation occurs in 25% of these patients. 5. Sensorineural hearing loss. 6. Constitutes about 5% of hereditary deafness.

M. Hermann's Syndrome.

1. Autosomal dominant. 2. Onset of photomyoclonus and sensorineural hearing loss in late of childhood or adolescence. 3. Diabetes mellitus. 4. Progressive dementia. 5. Pyelonephritis and glomerulonephritis.

N. Hurler's Syndrome (Gargoylism).

1. Autosomal recessive. 2. Abnormal mucopolysaccharide are deposited in tissues (when mucopolysaccharide is deposited in the neutrophiles they are called Adler bodies); middle ear mucosa with large foamy gargoyle cells staining PAS positive. 3. Chondroitin sulfate B and heparitin are found in urine. 4. Forehead prominence with coarsening of the facial features and low-set ears. 5. Mental retardation. 6. Progressive corneal opacities. 7. Hepatosplenomegaly. 8. Mixed hearing loss. 9. Dwarfism. 10. Cerebral storage of three gangliosides, GM3, 2, 1. 11. Beta-galactosides deficient.

O. Hunter's Syndrome.

1. Same as above except that it is sex-linked.

13 P. Jervell-Lange-Nielson Syndrome.

1. Autosomal recessive. 2. Profound bilateral sensorineural hearing loss; high frequencies more severely impaired. 3. Associated with heart disease (prolonged QT interval on ECG); has been associated with Stokes-Adams disease. 4. Recurrent syncope. 5. Usually terminates fatally; death is sudden. 6. Histopathologically, PAS-positive nodules can be seen in the cochlea.

Q. Laurence-Moon-Biedl-Bardet Syndrome.

1. Autosomal recessive. 2. Dwarfism. 3. Obesity. 4. Hypogonadism. 5. Retinitis pigmentosa. 6. Mental retardation. 7. Sensorineural hearing loss.

R. (Recessive) Malformed Low-Set Ears and Conductive Hearing Loss.

1. Autosomal recessive. 2. 50% show mental retardation.

S. (Dominant) Mitral Insufficiency, Joint Fusion and Hearing Loss.

1. Autosomal dominant with variable penetrance. 2. Conductive hearing loss, usually due to fixation of the stapes. 3. Narrow external auditory canal. 4. Fusion of the cervical vertebrae, carpal, and tarsal bones.

T. Möbius' Syndrome (Congenital Facial Diplegia).

1. Autosomal dominant, ? recessive. 2. Facial diplegia. 3. External ear deformities. 4. Ophthalmoplegia. 5. Hands or feet may be missing. 6. Mental retardation. 7. Paralysis of the tongue. 8. Mixed hearing loss.

14 U. (Dominant) Saddle Nose, Myopia, Cataract, and Hearing Loss.

1. Autosomal dominant. 2. Saddle nose. 3. Severe myopia. 4. Juvenile cataract. 5. Sensorineural hearing loss which is progressive, moderately severe, and of an early onset.

V. Norrie's Syndrome.

1. Autosomal recessive. 2. Congenital blindness due to pseudotumor retinae. 3. Progressive sensorineural hearing loss in 30% of patients.

W. Pendred's Disease.

1. Autosomal recessive. 2. Variable amount of bilateral hearing loss secondary to atrophy of the organ of Corti. A U-shaped audiogram is often seen. 3. These patients are euthyroid. They develop diffuse goiter at the time of puberty. It is said that the metabolic defect is faulty iodination of tyrosine. 4. Positive perchlorate test. 5. The goiter is treated with exogenous hormone to suppress TSH secretion. 6. Normal IQ. 7. Unlike congenital cretinism, the bony petrous pyramid is well developed. 8. Constitutes 10% of hereditary deafness.

X. Refsum's disease (Heredopathia Atactica Polyneuritiformis).

1. Autosomal recessive. 2. Retinitis pigmentosa. 3. Polyneuropathy,. 4. Ataxia. 5. Sensorineural hearing loss. 6. Visual impairment usually begins in the second decade. 7. Ichthyosis is often present. 8. Elevated plasma phytanic acid levels. 9. Etiology: Neuronal lipid storage disease and hypertrophic polyneuropathy.

Y. (Recessive) Renal, Genital, Middle Ear Anomalies.

1. Autosomal recessive. 2. Renal hypoplasia. 3. Internal genital malformation. 4. Middle ear malformation. 5. Moderate to severe conductive hearing loss.

15 Z. Richards-Rundel Disease.

1. Autosomal recessive. 2. Mental deficiency. 3. Hypogonadism (decreased urinary estrogen, pregnanediol, and total 17-ketosteroids). 4. Ataxia. 5. Horizontal nystagmus to bilateral gazes. 6. Sensorineural hearing loss begins at infancy. 7. Muscle wasting in early childhood and absent deep tendon reflexes.

AA. Taylor's Syndrome.

1. Autosomal recessive. 2. Unilateral microtia or anotia. 3. Unilateral facial bone hypoplasia. 4. Conductive hearing loss.

BB. Trisomy 13-15 (Group D) (Patau's Syndrome).

1. Low-set pinnae. 2. Atresia of external auditory canals. 3. Cleft lip and cleft palate. 4. Colobomas of the eyelids. 5. Micrognathia. 6. Tracheoesophageal fistula. 7. Hemangiomas. 8. Congenital heart disease. 9. Mental retardation. 10. Mixed hearing loss. 11. Hypertelorism. 12. Incidence 0.45:1.000 live births. 13. Patients usually die early in childhood.

CC. Trisomy 16, 17, 18 (Group E).

1. Low-set pinnae. 2. External canal atresia. 3. Micrognathia, high-arched palate. 4. Peculiar finger position. 5. Prominent occiput. 6. Cardiac anomalies. 7. Hernias. 8. Pigeon breast. 9. Mixed hearing loss. 10. Incidence 0.25-2:1.000 live births. 11. Ptosis. 12. Patients usually die early in life.

16 DD. Trisomy 21 or 22 (Down's Syndrome) (G Trisomy).

1. Extra chromosome on no. 21 or no. 22. 2. Mental retardation. 3. Short stature. 4. Brachycephaly. 5. Flat occiput. 6. Slanted eyes. 7. Epicanthus. 8. Strabismus, nystagmus. 9. Seen in association with leukemia. 10. Subglottic stenosis not uncommon. 11. Decreased pneumatized or absent frontal and sphenoid sinuses. 12. 1:600 live births.

EE. Turner's Syndrome.

1. Not inherited; ? due to intrauterine insult. 2. Low hairline. 3. Webbing of neck and digits. 3. Widely spaced nipples. 4. XO; 80% are sex chromatin negative. 6. Gonadal aplasia. 7. Incidence 1:5.000 live births (Klinefelter's syndrome is XXY). 8. Ossicular deformities. 9. Low-set ears. 10. Mixed hearing loss. 11. Large ear lobes. 12. Short stature. 13. Abnormalities found in the heart and kidney. 14. Some with hyposomia.

FF. (Dominant) Urticaria, Amyloidosis, Nephritis, and Hearing Loss.

1. Autosomal dominant. 2. Recurrent urticaria. 3. Amyloidosis. 4. Progressive sensorineural hearing loss due to degeneration of the organ of Corti; ossification of the basilar membrane, and cochlear nerve degeneration. 5. Patient usually dies of uremia.

17 GG. Usher's Syndrome (Recessive Retinitis Pigmentosa with Congenital Severe Deafness).

1. Autosomal recessive. 2. Retinitis pigmentosa giving rise to progressive visual loss. The patient is usually completely blind by the second or third decade. 3. These patients usually are born deaf secondary to atrophy of the organ of Corti. Hearing for low frequencies may be present in some patients. 4. Ataxia and vestibular dysfunction are very common. Usher's syndrome, among all congenital deafness, is the one most likely to include vestibular symptoms. 5. It constitutes 10% of hereditary deafness. 6. Gorlin et al classified Usher's syndrome into three types. a. Type I: Profound congenital deafness with the onset of retinitis pigmentosa by 10 years of age; has no vestibular responses; constitutes 90% of all cases of Usher's syndrome. b. Type II: Moderate to severe congenital deafness with the onset of retinitis pigmentosa in late teens or early 20s; normal or decreased vestibular response; constitutes 10% of all cases. c. Type III: Progressive hearing loss; retinitis pigmentosa begins at puberty; constitutes less than 1% of all cases. Types I, II, III are autosomal recessive. c. Type IV: X-linked inheritance; phenotype similar to type II.

HH. Weil's Syndrome.

1. Nephritis. 2. Hearing loss. 3. Autosomal dominant.

V. Middle and External Ear Congenital Deformities

A. These have been classified into class I, II, III. However, the classification is less commonly used than that for inner ear developmental anomaly.

1. Class I.

a. Normal auricle in shape and size.

b. Well pneumatized mastoid and middle ear.

c. Ossicular problem.

d. This type is the most common.

2. Class II.

a. Microtia.

b. Atretic canal and abnormal ossicles.

18 c. Normal aeration of mastoid and middle ear.

3. Class III.

a. Microtia.

b. Atretic canal and abnormal ossicles.

c. Middle ear and mastoid poorly aerated.

B. External deformity does not correlate necessarily with the middle ear abnormality.

C. Patients with congenitally fixed footplate have the following points to differentiate them from those patients with otosclerosis.

1. Onset in childhood.

2. Nonprogressive.

3. Negative family history.

4. Flat 50-60 dB conductive hearing loss.

5. Carhart's notch is not present.

6. Schwartze's sign is not present.

19 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 10: Facial Nerve Paralysis

Evaluation

Evaluation of patients with facial nerve paralysis must be a careful process including a detailed history, physical examination, audiometry with impedance testing, and appropriate x-rays. It is important to separate a central facial paralysis from a peripheral type before embarking on a diagnostic plan. A central unilateral facial paralysis usually will involve only the lower face as the innervations of the upper face are derived from crossed and uncrossed fibers. Paralysis of the peripheral type will involve the upper and lower face. The common causes of facial paralysis are found in Table 10-1. Diagnosis of lesions from a standpoint of level of impairment is found in Table 10-2. It is imperative not to label a facial paralysis as Bell's palsy prior to an exhaustive diagnostic workup to rule out a definitive etiology. By definition, Bell's palsy suggests idiopathic facial paralysis.

Table 10-1. Common Causes of Facial Paralysis

Congenital

Dystrophia myotonica, Möbius syndrome (facial diplegia associated with other cranial nerves), Bell Melkersson syndrome (furrowed tongue, faciolabial edema), familial.

Traumatic

Basal skull fracture, facial injuries, penetrating injury to middle ear, altitude paralysis, use of forceps at birth, molding trauma at birth.

Neurologic

Landry-Guillain-Barre syndrome (ascending paralysis), multiple sclerosis, myasthenia gravis, opercular syndrome (cortical lesion in facial motor area), Millard-Gubler syndrome (abducens palsy, with contralateral hemiplegia due to lesion in base of pons involving corticospinal tract).

Infectious

External otitis, otitis media, mastoiditis, chicken pox, herpes zoster (Ramsey Hunt syndrome), encephalitis, poliomyelitis (type 1), mumps, mononucleosis, leprosy, influenza, coxsackievirus, malaria, syphilis, sarcoidosis, Heerfordt's disease - uveoparotid fever.

Metabolic

Diabetes mellitus, hyperthyroidism.

1 Neoplastic

Cholesteatoma, VIII nerve tumor, glomus jugulare, leukemia, meningioma, hemangioblastoma, sarcoma, carcinoma (invading or metastatic), anomalous sigmoid sinus, hemangioma of tympanum, hydradenoma (external canal), osteopetrosis, facial nerve tumor (cylindroma), schwannoma, teratoma, Hand-Schüller-Christian disease.

Toxic

Thalidomide (Miehlke's syndrome of cranial nerve VI and VII with congenital malformed external ears and deafness), tetanus, diphtheria.

Iatrogenic

Mandibular block anesthesia, antitetanus serum, vaccine treatment for rabies, post polio immunization, parotid surgery, mastoid surgery, posttonsillectomy, and postadenoidectomy.

Table 10-2. Diagnosis of Lesions from Level of Impairment

Supranuclear: Good tone, intact upper face, presence of spontaneous smile, neurologic deficits.

Cerebrovascular accident, trauma.

Nuclear: Involvement of the sixth and seventh cranial nerves, corticospinal tract signs.

Vascular or neoplastic, poliomyelitis, multiple sclerosis, encephalitis.

Angle: Involvement of vestibular and cochlear portions of the eight cranial nerve; the facial nerve, particularly taste, lacrimation and salivation may be altered; the fifth and later ninth, tenth, and eleventh cranial nerves may become impaired.

Neurinoma, meningioma, fracture, cholesteatoma, arachnoid cyst.

Geniculate ganglion: Facial paralysis, hyperacusis, alteration of lacrimation, salivation, and taste.

Herpes zoster oticus, fracture, Bell's palsy, cholesteatoma, neurinoma, arteriovenous malformation, meningioma.

Tympanomastoid: Facial paralysis, alteration in salivation and taste; lacrimation intact.

Bell's palsy, cholesteatoma, fracture, infection.

Extracranial: Facial paralysis (usually a branch is spared), salivation and taste intact, deviation of jaw to normal side.

Trauma, tumor, parotid carcinoma, pharyngeal carcinoma.

2 Important Point in Diagnosis

1. Bilateral simultaneous facial paralysis is a sign of central or generalized disease and should not be confused with Bell's palsy.

2. Patients with slowly progressive facial paralysis, whether partial or total, with no evidence of recovery after 6 months, should be suspected of a neoplasm involving the facial nerve.

3. Facial paralysis associated with pain, sensorineural hearing loss, vertigo, and a red pinna with vesicles have herpes zoster oticus or Ramsey Hunt syndrome, the vesicles being present in the area of sensory distribution of the facial nerve.

4. Hitzelberger's sign: Decreased sensitivity in the concha corresponding to the sensory distribution of the seventh nerve is suggestive of a space-occupying lesion in the internal auditory canal.

5. The incidence of severe degeneration in Bell's palsy approximates 15%. However, in herpes zoster the incidence approximates 40%.

6. Ten percent of the patient with Bell's palsy have a positive family history. Recurrent facial paralysis recurs in 10% of the patients with Bell's palsy, and is much more common on the ipsilateral and contralateral sides.

7. Thirty percent of the patients with recurrent facial paralysis on the same side have been found to have tumors.

Steps in the Evaluating a Bell's Palsy

Is it partial or total?

Partial

No treatment. Close follow-up.

Total

1. Determine the level of involvement:

a. Taste impairment? b. Presence of stapedial reflex? c. Schirmer's test. It is important to note that this is a gross test and it is of no significance unless the normal eye tears at least 30% more than the involved eye.

3 2. One or more of the following tests can be performed:

a. Nerve excitability test b. Conduction latency test c. Strength-duration studies d. Electromyography (EMG) e. Maximal stimulation test f. Salivary flow.

When increasing difficulty in eliciting responses in these tests is noted, one should consider that thde nerve is showing signs of denervation. If one believes in decompression of the nerve, it should be done as soon as it is feasible.

Nerve Excitability Test

This test uses a once per second square-wave pulse, 1 msec in duration. This test has no clinical use in a partial paralysis or within 3 days of total paralysis. After the third day of total paralysis, the normal side is first tested to obtain the threshold needed to elicit the slightest flicker of facial muscle movement. The electrode is placed percutaneously along the stylomastoid foramen and then along the main branches of the facial nerve. After recording the thresholds for the normal side, the electrode is placed at the same locations on the diseased side. The respective thresholds are then compared. A greater than 3-4 mamp difference is considered significant, suggesting denervation. For those who believe in decompression of the facial nerve, the nerve excitability test should be performed daily after the third day of total paralysis. As soon as a consistent 3-4 mamp or more difference in threshold between the normal and the abnormal sides appears, decompression is performed. In the nerve excitability test, one must avoid stimulating the muscle directly so that a false threshold is not obtained.

Conduction Latency Test

The conduction latency test also uses a once per second square-wave pulse, 1 msec in duration. A secon electrode is placed in a distal facial muscle. The time taken by the impulse to reach the distal electrode is recorded as conduction latency. The normal conduction time from the angle of the mandible to the facial muscle in the midline is about 4 msec. Like the nerve excitability test, it does not demonstrate prolonged conduction times until 72 hours after denervation. After 72 hours, a completely transected nerve shows increasing conduction time until no excitability is demonstrable. A lengthening of conduction time also may imply partial denervation.

Unlike the nerve excitability test, the conduction latency test is harder to perform both for the doctor and the patient. Hence it is not used clinically in the office.

Strength-Duration Studies

A particular muscle is selected for this test. A square-wave pulse of varying duration and intensity is applied until a just visible twitch is noted. As one goes from a longer pulse duration to a shorter pulse duration, the threshold needed to elicit a just visible twitch is

4 recorded. The intensities for various pulse durations are recorded for the normal side. A denervated nerve will show considerably higher thresholds. The strength-duration curve is not altered in neuropraxia and is not altered till 7 days after denervation.

Rheobase: The strength of current just strong enough to depolarize (mamp).

Chronaxie: The length of duration needed to depolarize using an intensity two times the rheobase (msec).

Electromyography (EMG)

This test determines the activity of the muscle itself. A needle electrode is inserted into the muscle and recordings are made during rest and voluntary contraction. Fig. 10-1 illustrates a voluntary unit discharge, fibrillation potential, and polyphasic reinnervation potential. Degeneration of a lower motor nerve is followed in 14-21 days by spontaneous activity called fibrillation potential. Hence the EMG is not of diagnostic value until 2 weeks after denervation. The practical clinical usage of EMG is in the determination of reinnervation. Polyphasic reinnervation potentials are present 6-12 weeks before clinical return of facial function.

Maximum Stimulation Test

The maximum stimulation test is similar to the nerve excitability test except that it uses maximal rather than minimal stimulation. The main trunk as well as each major portion of the distal branches of the nerve (forehead, eye, nose, mouth, lower lip, and neck) on the normal and abnormal side are stimulated with an intensity that produces discomfort. The results of the test are expressed as a difference in facial muscle movement between the normal and the involved side. The finding of a difference is considered evidence of abnormality.

Salivary Flow Test

The salivary flow test is based on the fact that the preganglionic parasympathetic nerve fibers are on the outside of the VII nerve bundle; hence it is assumed that these fibers will be injured before the motor fibers. The proponents of this test further reason that the nerve excitability test examines the nerve distal to the injury while the salivary flow test checks the nerve at the site of injury.

After anesthetizing the anterior floor of the mouth, the test is performed by first dilating the Wharton's duct. A polyethylene tube is then cannulated into each duct. Lemon juice is next used to stimulate salivary flow of which the number of drops secreted per minute is counted for each side. A difference of 70% or greater is considered significant and warrants surgical decompression of the VII nerve.

Electroneuronography

Electroneuronography was popularized by Ugo Fisch. Similar in principle to the maximal stimulation test except that instead of visual observation of degree of response, there

5 is a recording of the summation potential on an instrument similar to an EMG recording device. The normal side is compared with the abnormal side and the degree of degeneration estimated from the difference between the amplitude of the measured summation potentials on the two sides. Fisch recommends surgical decompression when the evoked summation potential is 10% or less than the normal side indicating, in his impression, 90% degeneration on the affected side. This should be done within 2 weeks of the onset of paralysis. Other investigators have felt that if the reduction was greater than 25%, decompression was indicated since by the time the level reached 10%, results were uniformly poor.

Treatment of Bell's Palsy

Before one can specifically advocate one mode of treatment over another, it is imperative to realize that the great majority of Bell's palsy patients have either partial paralysis or total paralysis without degeneration, i.e. maintaining the neuropraxia state. It is also fairly well recognized that, unless denervation has occurred, the patient more than likely will recover spontaneously with little synkinesis. Hence surgical treatment, if proposed, is reserved for those with total paralysis that have shown signs of denervation. There is no conclusive evidence to date that surgical decompression is of definite benefit. Some protocols treat Bell's palsy of all severities with steroids, others treat only cases of total facial palsy with steroids. Some clinicians believe that if the nerve is allowed to degenerate completely, the prognosis is poor and synkinesis is common.

A Guideline for the Management of Facial Nerve Paralysis

Bell's Palsy

A complete otologic, audiometric, and radiographic workup is needed.

Partial: No treatment.

Total:

1. Determine level of involvement. 2. Daily electrical test until:

a. Threshold of the involved side increases to 4 mamp. b. There is evidence of some return of facial function.

If (a) is found, decompression of the facial nerve from the stylomastoid foramen to the level of blockage is performed. A "middle fossa" decompression should be done if the greater superficial petrosal nerve is involved.

Post Ear Surgery

Rule out effects of local anesthetics and too tight a mastoid packing.

1. Delayed onset (partial or complete): follow like Bell's palsy. 2. Immediate onset (partial or complete): explore the nerve before the "sun sets".

6 Traumatic (Head Injury)

1. Delayed onset (partial or complete): follow like Bell's palsy. 2. Immediate onset (partial or complete): explore the nerve when patient is stabilized.

Herpes Zoster Oticus

The most common motor nerve involved is the VII nerve, the next are III, IV, and VI. Treat like Bell's palsy.

Chronic Otitis Media

Partial or complete: mastoidectomy and facial nerve decompression; ? tympanoplasty.

Acute Otitis Media

1. ? Treat like Bell's palsy. 2. ? Simple mastoidectomy. 3. ? Myringotomy.

Acute Mastoiditis with Facial Paralysis

Treatment includes simple mastoidectomy and decompression of the facial nerve and myringotomy or simple mastoidectomy and myringotomy.

Another concept for the management of facial nerve paralysis was advocated by Sunderland. His classification of facial nerve injury and recommended treatment is outlined in Table 10-3.

Table 10-3. Classification and Treatment of Facial Nerve Injury

First-degree (neurapraxia). Onset to third day. Damming of proximal and distal flow of axoplasm. Lacrimation > 70%. Salivation > 70%. Maximal stimulation equal. ENG equal. Treatment: Eye care. Sedation. Analgesic. Reassurance. Reevaluate incomplete paralysis in 1 week. If paralysis becomes complete reevaluate immediately. Complete paralysis should be reevaluated and retested every other day until recovery or placement in second-degree. Natural history: Complete recovery beginning in 1-3 week. Surgical results: No surgery necessary.

First-to-second degree (neurapraxia-axonotmesis). Third to fifth day. Disruption of axons. Lacrimation < 25%. Salivation < 25%. Maximal stimulation lowered. ENG < 50%. Treatment: Supportive care as for first-degree. Surgical decompression to labyrinthine segment. Natural history: Fair recovery. Minimal cosmetic and functional impairment beginning in 3 weeks to 2 months. Surgical results: Complete recovery beginning 7-10 days.

Second-to-third-degree (axonotmesis-neurotmesis). Fifth to fourteenth day. Disruption of axons and myelin tubes. Lacrimation - dry eye. Salivation < 25%. Maximal stimulation - lowered to absent. ENG = 25%. Treatment: Same as second-degree. Natural history: Poor recovery. Obvious incomlete recovery with marked complications of faulty regeneration: tic,

7 spasms, synkinesis; beginning 2-4 months. Surgical results: Fair recovery beginning 3 weeks to 2 months.

Third-to-fourth-degree (neurotmesis). Disruption of perineurium, myelin tubes, and axons. Lacrimation - absent if lesion at or proximal to geniculate ganglion. Salivation < 25%. Maximal stimulation - response lost 2 or 3 days. ENG - response lost 3-5 days. Treatment: Ideally, explore and repair immediately or within 30 days. Natural history: If nerve is completely severed some spontaneous recovery may occur in rare instances. If incompletely severed, recovery may occur but results in marked facial weakness with no recovery of parts of face or mass movement. Surgical results: Repair within 30 days: 90%. Excellent (symmetry, eye and mouth movement), or good symmetry and movement beginning 4-10 months.

Fifth-degree. Disruption of epineurium, perineurium, myelin, and axons. Lacrimation - same. Salivation - same. Maximal stimulation - same. ENG - same. Treatment: Same. Natural history: Same. Surgical results: Same.

Miscellaneous

1. Neuropraxia: Blockage due to localized pressure without axonal degeneration or nerve sheath interruption. ? Chemical basis.

2. Axonotmesis: Blockage of replenishment of axoplasm to distal segment. Degeneration of myelin sheath without disruption of neurolemmal sheath.

3. Neurotmesis: Disruption of nerve trunk.

4. Synkinesis: A single axon innervating widely separated facial muscles. It also has been postulated that unmyelinated nerve regeneration gives rise to more synkinesis and as more myelin is laid down, less synkinesis is noted.

5. Möbius syndrome: Facial paralysis in the newborn due to central nerve lesion or agenesis of facial muscles.

6. Melkersson-Rosenthal syndrome: Recurrent unilateral or bilateral facial palsy associated with chronic or recurrent edema of face and with fissured tongue. Unknown etiology. Peak age is 20s; histologically, dilated lymphatic channels, giant cells, and inflammatory cells are seen.

7. "Crocodile tears": Regenerating fibers innervate the lacrimal gland instead of the submaxillary gland.

8. Faradic current: Is a high frequency interrupted current that stimulates the nerve directly and elicits an all-or-none response.

9. Galvanic current: Is a constant direct current that stimulates the muscles directly.

8 10. Bell's phenomenon: The eyeball turns up and out during an attempt to close the eyes.

11. Facial paralysis of central origin is characterized by:

a. Intact frontalis and orbicularis oculi.

b. Intact mimetic function.

c. Absence of Bell's phenomenon.

12. Blood supply of the facial nerve (see Fig. 10-2):

a. ECA --> Posterior auricular artery --> Stylomastoid artery.

b. ECA --> Middle meningeal artery --> Greater superficial petrosal artery.

13. Distances:

Pons to IAM = 23-24 mm IAM = 7-8 mm Labyrinthine = 3-4 mm Tympanic = 12-13 mm Mastoid = 15-20 mm Parotid before branching = 15-20 mm Whole length = 75-89 mm.

14. The chorda tympani branches off at about 5-7 mm before the stylomastoid foramen.

15. Facial nerve paralysis not involving the greater superficial petrosal nerve would give a "tearing" eye because of:

a. Paralysis of Horner's muscle that dilates the nasolacrimal duct orifice.

b. Ectropia and so produces malposition of the puncta.

c. Absenmce of winking, i.e. lack of the pumping action.

16. The most likely areas of compression in Bell's palsy have been noted to be in the stylomastoid area and around the pyramidal eminence.

17. Korczyn reported that among 130 patients with Bell's palsy, 66% had either frank diabetes or an abnormal glucose tolerance test. It also has been stated that the percentage of denervation in Bell's palsy is higher in diabetics.

18. In parotid surgery, the facial nerve can be identified at 6-8 mm below the inferior "drop off" of the tympanomastoid fissure. This was described by H. G. Tabb.

9 19. Twenty-five percent of longitudinal fractures involve the facial nerve; 50% of transverse fractures involve the facial nerve.

20. The facial nerve regenerates at 3 mm/day.

21. Incapacitating facial spasm (particularly of the orbicularis oculi) can be treated by selective avulsion of the facial nerve branches through a parotidectomy approach.

22. Facial nerve innervates:

a. Stylohyoid muscle b. Posterior belly of digastric muscle c. Occipitofrontalis muscle - via posterior auricular branch d. External auricular muscles - via posterior auricular branch e. Orbicularis oculi - temporal division f. Occipitofrontalis - temporal division g. Anterior and superior auriculares - temporal division h. Orbicularis oculi - upper zygomatic i. Zygomatic muscles - lower zygomatic j. Buccinator - buccal k. Around nose and mouth - buccal l. Depressor anguli oris - mandibular m. Depressor labii inferioris - mandibular n. Orbicularis oris - mandibular o. Platysma - cervical.

23. Motor root from the motor facial nucleus at the level of pons gives muscular branches (see above) and stapedius nerve.

24. N. intermedius brings taste fibers from nucleus solitarius through chorda tympani to anterior two-thirds of the tongue.

25. N. intermedius brings parasympathetic fibers from superior salivary nucleus to the:

a. Lacrimal gland, palatine and nasal glands through the greater superficial petrosal nerve, vidian nerve, sphenopalatine ganglion, travelling across the maxillary nerve, with ophthalmic nerve and lacrimal nerve.

b. Parotid gland through the deep petrosal nerve, tympanic plexus, lesser superficial petrosal nerve, otic ganglion and then via auriculotemporal nerve.

c. Submaxillary and sublingual gland through chorda tympani that becomes attached to lingual nerve, to submandibular ganglion.

26. Tympanic plexus is formed by VII, IX and X and caroticotympanic nerve that carries sympathetic fibers from carotid plexus.

10 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 11: Embryology of the Clefts and Pouches

Correlation between Age and Size of Embryo

2.5 weeks = 1.5 mm 3.5 weeks = 2.5 mm 4 weeks = 5 mm 5 weeks = 8 mm 6 weeks = 12 mm 7 weeks = 17 mm 8 weeks = 23 mm 10 weeks = 40 mm 12 weeks = 56 mm 16 weeks = 112 mm 5-10 months = 160-350 mm

Development of the Branchial Arches

1. The first 8 weeks constitutes the period of greatest embryonic development of the head and neck. There are five arches named pharyngeal or branchial arches. Between these arches are the grooves or clefts externally and the pouches internally. Each pouch has a ventral or dorsal wing. The derivatives of arches are usually of mesoderm origin. The groove is lined by ectoderm while the pouch is lined by entoderm (se Fig. 11-1).

Each arch has an artery, nerve, and cartilage bar. These nerves are anterior to their respective arteries except in the fifth arch where the nerve is posterior to the artery. Embryologically, the arch after the fourth is called the fifth or sixth arch depending on the theory one follows. For simplicity in this synopsis, it will be referred to as the fifth arch. Caudal to all the arches lies the XII nerve. The sternocleidomastoid muscle is derived from the cervical somites posterior and inferior to the above arches.

2. There are two ventral and two dorsal aortas in early embryonic life. The two ventral ones fuse completely while the two dorsal ones fuse caudally only (Fig. 11-2a). In the course of embryonic development, the first and second arch arteries degenerate. The second arch artery has an upper branch which passes through a mass of mesoderm which later chondrifies and ossifies as the stapes. This stapedial artery degenerates in late fetal life. The third arch artery is the precursor of the carotid artery in both left and right sides. The left fourth arch artery becomes the arch of the aorta. The right fourth arch artery becomes the proximal subclavian. The rest of the right subclavian and the left subclavian are derivatives of the seventh segmental arteries. The left fifth arch artery becomes the pulmonary artery and ductus arteriosus. The right fifth arch artery becomes the pulmonary artery with degeneration of the rest of this arch vessel (Fig. 11-2b).

3. (a) Should the right fourth arch artery degenerate and the right subclavian arise from the dorsal aorta instead as shown in Fig. 11-2c, the right subclavian would become posterior to the esophagus, thus causing a constriction of the esophagus without any effect on the

1 trachea (dysphagia lusoria). (b) The innominate artery arises ventrally. Hence, when it arises too far from the left, an anterior compression of the trachea results.

4. The fifth arch nerve is posterior and caudal to the artery. As the connection on the right side between the fifth arch artery (pulmonary) and the dorsal aorta degenerates, the nerve (recurrent laryngeal nerve) loops around the fourth arch artery which subsequently becomes the subclavian. On the left side, the nerve loops around the ductus arteriosus and the aorta.

Table 11-1. The Branchial Arches and Their Derivatives

First arch: Semilunar ganglion. V. Mandible. Head, neck, manubrium of malleus. Body and short process of incus. Anterior malleal ligament. Sphenomandibular ligament. Tensor tympani. Mastication muscles. Anterior belly of digastric muscle. Tensor palati muscle.

Second arch: Geniculate ganglion. VII. Manubrium of malleus. Long process of incus. All of stapes except vestibular portion of footplate and annular ligament. Styloid process. Stylohyoid ligament. Lesser cornu of hyoid. Part of body of hyoid. Stapedius muscle. Facial muscles. Buccinator, posterior belly of digastric muscles. Styloid muscle. Part of pyramidal eminence. Lower part of facial canal.

Third arch: IX. Greater cornu of hyoid and rest of hyoid. Stylopharyngeus muscle.

Fourth arch: Superior laryngeal nerve. Thyroid cartilage, cuneiform, inferior pharyngeal constrictor, cricopharyngeus, cricothyroid muscles.

Fifth arch (Often called the sixth arch from the standpoint of evolution and comparative anatomy): Recurrent laryngeal nerve. Cricoid, arytenoids, corniculate, trachea, intrinsic laryngeal muscles.

Derivatives of the Pouches

1. Each pouch has a ventral and a dorsal wing. The fourth pouch has an additional accessory wing. The entodermal lining of the pouches proliferates into glandular organs.

First pouch: Dorsal and ventral: Middle ear cavity.

Second pouch: Dorsal: Middle ear cavity. Ventral: Tonsillar fossa and palatine tonsil.

Third pouch: Dorsal: Parathyroid 3. Ventral: Thymus.

Fourth pouch: Dorsal: Parathyroid 4. Ventral: ? Accessory: Ultimobranchial body.

2. During embryonic development, the thymus descends caudally pulling with it parathyroid 3. Consequently, parathyroid 3 is inferior to parathyroid 4 in the adult.

3. The fate of the ultimobranchial body is unknown.

2 4. As these "out-pocketing" pouches develop into glandular elements, their connections with the pharyngeal lumen referred to as pharyngobranchial ducts become obliterated. Should obliteration fail to occur, a branchial sinus (cyst) is said to have resulted.

The second pharyngobranchial duct (between the second and third arches) is believed to open into the tonsillar fossa, while the third pharyngobranchial duct opens into the pyriform sinus and the fourth opens into the lower part of the pyriform sinus or larynx. An alternative school of thought believes that branchial sinuses and cysts are not remnants of patent pharyngobranchial ducts, but are rather remnants of the cervical sinus of His (Davies J: Embryology of the Head and Neck in Relation to the Practice of Otolaryngology, A Manual, AAOO, 1965).

5. The cutaneous openings of branchial sinuses, if present, are always anterior to the anterior border of the sternocleidomastoid muscle. The tract always lies deep to the platysma muscle which is derived from the second arch (Fig. 11-3).

The course of a third arch branchial cyst:

a. Deep to second arch derivatives and superficial to third arch derivatives.

b. Superficial to the XII nerve and anterior to the sternocleidomastoid.

c. In close relationship with the carotid sheath but superficial to it.

d. Superficial to the IX nerve, pierces middle constrictor, deep to stylohyoid ligament, opens into tonsillar fossa.

The course of a second arch branchial cyst:

a. Again, it is subplatysmal and opens externally anterior to the sternocleidomastoid muscle.

b. Superficial to the XII nerve, deep to the internal carotid artery and the ninth nerve.

c. Pierces the thyrohyoid membrane above the internal branch of the superior laryngeal nerve and opens into the pyriform fossa,.

The course of a fourth arch branchial cyst:

Right:

a. The tract lies low in the neck beneath the platysma and anterior to the sternocleidomastoid muscle.

b. It loops around the subclavian and deep to it, deep to the carotid, lateral to the XII nerve, inferior to the superior laryngeal nerve, and opens into the lower part of the pyriform sinus or into the larynx.

3 Left:

a. Since the fourth arch vessel is the adult aorta, the cyst may be intrathoracic, medial to the ligament arteriosus and the arch of aorta.

b. Lateral to the XII, inferior to the superior laryngeal nerve.

c. Opens into the lower pyriform sinus or into the larynx.

First Arch (Mandibular Arch)

Meckel's cartilage: Upper part: Malleus, head and neck; incus body, short process.

Meckel's cartilage: Intermediate: Anterior malleal ligament; sphenomandibular ligament.

Meckel's cartilage: Lower part: Mandible.

Mesoderm: Tensor tympani, masticator muscles, anterior belly of digastric, tensor palati.

Nerve: V. Semilunar ganglion.

Artery: "Degenerates".

Second Arch (Hyoid Arch)

Recihert's cartilage: Manubrium of malleus, long process of incus, lenticular process, stapes (except vestibular part of footplate), styloid process, pyramidal eminence, stylohyoid ligament, lesser cornu of the hyoid, part of body of the hyoid, lower half of facial canal.

Mesoderm: Platysma, stapedius muscle and tendon, facial muscles, auricular muscles, posterior belly, stylohyoid muscle.

Nerve: VII. Geniculate ganglion.

Artery: "Degenerates" (stapedial artery).

Third Arch

Cartilage bar: Greater cornu of the hyoid, part of body of the hyoid.

Mesoderm: Stylopharyngeus muscle.

Nerve: IX. Superior and inferior ganglia.

Artery: Common and internal carotids.

4 Fourth Arch

Cartilage bar: Thyroid cartilage, cuneiform cartilage.

Mesoderm: Inferior pharyngeal constrictor, cricothyroid and cricopharyngeus muscle.

Nerve: Superior laryngeal nerve. Jugular and nodose ganglion.

Artery: Left: Aorta. Right: Proximal subclavian (the rest derived from seventh segmental artery).

Fifth Arch (? Sixth)

Cartilage bar: Cricoid, arytenoid, corniculate.

Mesoderm: Intrinsic muscles of larynx (except cricothyroid), trachea.

Artery: Left: Pulmonary, ductus arteriosus. Right: Pulmonary.

Nerve: Recurrent laryngeal nerve.

Embryology of the Thyroid Gland

On a 4-week-old embryo, a ventral (thyroid) diverticulum of endodermal origin can be identified between the first and second arches on the floor of the pharynx. It also is situated between the tuberculum impar and the copula. The tuberculum impar together with the lingual swellings becomes the anterior two-thirds of the tongue while the copula is the precursor of the posterior one-third of the tongue. The ventral diverticulum develops into the thyroid gland. During development, it descends caudally within the mesodermal tissues. At 4.5 weeks, the connection between the thyroid diverticulum and the floor of the pharynx begins to disappear. By the sixth week, it should be obliterated and atrophied. Should it persist through the time of birth or thereafter, a thyroglossal duct cyst is present. This tract travels through the hyoid and reaches the foramen cecum (Fig. 11-4).

Embryology of the Tongue

The tongue is derived from ectodermal origin (anterior two-thirds) and entodermal origin (posteriorly). At the fourth week, two lingual swellings are noted at the first arch and a swelling, the tuberculum impar, appears between the first and the second arches. These three prominences develop into the anterior two-thirds of the tongue. Meanwhile, another swelling is noted between the second and third arches, called the copula. It develops into the posterior one-third of the tongue. On the seventh week the somites from the high cervical areas differentiate into voluntary muscle of the tongue. The circumvallate papillae develop between the eight and twentieth week while filiform and fungiform papillae develop at the eleventh week (Table 11-2).

5 Table 11-2. Embryonic Development of the Tongue

Fourth week: Tuberculum impar. Lingual swellings. Copula.

Seventh week: Voluntary muscles. Nerve XII. Papillae. Tonsillar tissues.

Eight to twentieth week: Circumballate papillae.

Eleventh week: Filiform and fungiform papillae.

Embryology of the Tonsils and Adenoids

1. Palatine tonsil (8 weeks old) from second pouch (ventral or dorsal).

2. Lingual tonsil (6.5 weeks old) from between second and third arches ventrally.

3. Adenoids (16 weeks old) develop as a subepithelial infiltration of lymphocytes.

Embryology of the Salivary Glands

1. Parotid (5.5 weeks old). Ectodermal origin. First pouch.

2. Submaxillary (6 weeks old). Ectodermal origin. First pouch.

3. Sublingual (8 weeks old). Ectodermal origin. First pouch.

Embryology of the Nose

The nasal placode is of ectodermal origin and appears between the middle of the third and fourth week of gestation (Fig. 11-5A). It is of interest to note that, at this stage, the eyes are laterally placed, the auricular precursors lie below the mandibular process, and the primitive mouth is wide. Hence, abnormal embryonic development at this stage may result in these characteristics in postnatal life.

On the fifth week the placodes become depressed below the surface and appear as invaginated pits. The nasal pit extends backward into the oral cavity but is separated from it by the bucconasal membrane (Fig. 11-5B). This membrane ruptures at the seventh to eight week of gestation to form the posterior nares. Failure in this step of development results in choanal atresia. While the nasal pit extends backward, it also extends upward toward the forebrain area. Epithelium around the forebrain thickens to become specialized olfactory sensory cells.

Anteriorly, the maxillary process fuses with the lateral and medial nasal processes to form the anterior nares. The fustion between the maxillary process and the lateral nasal process also creates a groove called the nasolacrimal groove. The epithelium over the groove is subsequently buried, and when the epithelium is resorbed the nasolacrimal duct is formed, opening into the anterior aspect of the inferior meatus. This duct is fully developed at birth.

6 The frontonasal process (mesoderm) is the precursor of the nasal septum (Fig. 11-6a, b). The primitive palate (premaxilla) located anteriorly is also a derivative of the frontonasal process (mesoderm). Posteriorly (Fig. 11-7a, b), the septum lies directly over the oral cavity until the ninth week at which time the palatal shelves of the maxilla grow medially to fuse with each other and with the septum to form the secondary palate. The hard palate is formed by the eight to ninth week (Fig. 11-8) while the soft palate and the uvula are completed by the eleventh to twelfth week.

From the eight week to the 24th week of embryonic life, the nostrils are occluded by an epithelial plug. Failure to resorb this epithelium results in atresia or stenosis of the anterior nares.

Along the lateral wall of the nasal precursor, the maxilloturbinal is the first to appear. This is followed by the development of five ethmoturbinals and one nasoturbinal. Table 11-3 gives the derivatives of each embryonic anlage, and Table 11-4 gives a timetable of their development.

Table 11-3. Embryonic Anlagen and Their Derivatives

Maxilloturbinal Inferior concha First ethmoturbinal Middle concha Second and third ethmoturbinal Superior concha Fourth and fifth ethmoturbinal Supreme concha Nasoturbinal Agger nasi area.

Table 11-4. Timetable of Nasal Development

Inferior concha formed - 7th week. Middle concha formed - 7th week. Uncinate process formed - 7th week. Superior concha formed - 8th week. Cartilage laid down - 10th week. Vomer formed and calcified - 12th week. Ethmoid bone calcified - 20th week. Cribriform plate calcifies - 28th week. Perpendicular plate, crista galli calcifies - After birth.

Table 11-5 outlines the development of the paranasal sinuses.

Table 11-5. Development of Paranasal Sinuses

Maxillary sinus: Arises as a prolongation of the ethmoid infundibulum. At 12 weeks. Pneumatizes at birth. Reaches stable size at 18 years old.

Frontal sinus: Arises from the upper anterior area of the middle meatus. Starts at late fetal life or even after birth. Pneumatizes after 1 year. Full size at 20 years old.

7 Sphenoid sinus: Arises from the epithelial outgrowth of the upper posterior region of the nasal cavity in close relation with the sphenoid bone. Starts at 3rd fetal month. Pneumatization during childhood. Full size at 15 years old.

Ethmoid sinus: Arises from the evagination of the nasal mucosa into the lateral ethmoid mass at 6th fetal month. Pneumatization completed at 7 years old. Full size at 12 years old.

Embryology of the Larynx

Figure 11-9a, b, c, d depicts the embryonic development of the larynx between the eight and 28th week of fetal life.

The entire respiratory system is an outgrowth of the primitive pharynx. At 3.5 weeks, a groove called the laryngotracheal groove develops in the embryo at the ventral aspect of the foregut. This groove is just posterior to the hypobranchial eminence and is located closer to the fourth arch than to the third arch. In embryonic development, when a single tubal structure is to later become two tubal structures the original tube is first obliterated by a proliferation of lining epithelium, then, as resorption of the epithelium takes place, the second tube is formed and the first tube is recannulized. Hence, any malformation will involve both tubes. This process of growth accounts for the fact that more than 90% of traheoesophageal fistulae are associated with esophageal atresia. During development, the mesenchyme of the foregut grows medially form the sides, "pinching off" this groove to crease a separate opening. With further maturation, two separate tubes are formed: the esophagus and the laryngotracheal apparatus.

This laryngotracheal opening is the primitive laryngeal aditus and lies between the fourth and fifth arches. The sagittal slit opening is altered to become a T-shaped opening by the growth of three tissue masses:

1. The hypobranchial eminence which first appears on the third week. This mesodermal structure gives rise to the furcula which later develops into the epiglottis.

2. The two arytenoid masses which appear on the fifth week. Later, each arytenoid swelling shows two additional swellings which eventually mature into the cuneiform and corniculate cartilages.

As these masses grow betweent the fifth and seventh week, the laryngeal lumen is obliterated. On the ninth week the oval shape lumen is reestablished. Failure to recannulize may result in atresia or stenosis of the larynx. The true and false cords are formed between the eight and tenth week. The ventricles are formed at the twelfth week.

The two arytenoid masses are separated by an "interarytenoid notch" which later becomes obliterated. Failure of this obliteration to occur would result in a posterior cleft up to the cricoid cartilage and opening into the esophagus, the culprit of severe aspiration in the newborn.

8 The laryngeal muscles are derivatives from the mesoderm of the fourth and fifth arches and hence are innervated by the tenth nerve.

The infant larynx is situated at a level between the second and third cervical vertebrae. In the adult, it lies opposite the body of the fifth cervical vertebra.

Table 11-6 illustrates the muscular and cartilaginous development of the larynx.

Table 11-6. Laryngeal Muscular and Cartilaginous Development with Embryonic Age.

Muscular

4 weeks old: Inferior pharyngeal constrictor and cricothyroid muscles are formed.

5.5 weeks old: Interarytenoid and postcricoarytenoid muscles are formed.

6 weeks old: Lateral cricoarytenoid muscle is formed.

Cartilage

3 weeks old: Development of epiglottis takes place (hypobranchial eminence).

5 weeks old: Thyroid cartilage (fourth arch) and cricoid cartilage (fifth arch) appear.

7 weeks old: Chondrification of these two cartilages begins.

12 weeks old: Development and chondrification of arytenoid (fifth arch) and corniculate (fifth arch) takes place. Vocal process is the last to develop.

20 weeks old: Chondrification of the epiglottis occurs.

28 weeks old: Development of the cuneiform cartilage (fourth arch) occurs.

Ossification of Laryngeal Skeleton

Hyoid: Ossification from six centers. Starts at birth. Completed by 2 years old.

Thyroid: Starts at 20-23 years old. Starts at inferior margin. Extends posteriorly at each ala. Superior margin never ossify.

Cricoid: Starts at 25-30 years old. Incomplete. Starts at inferior margin.

Arytenoids: Starts at 25-30 years old.

Middle Ear

Cartilage is retained at the incudo-stapedial joint, the malleal-incudal joint, the stapedial base, the medial aspect of short crus of incus, and certain parts of manubrium of

9 malleus. Remodelling of bone continues in postnatal life in malleus and incus but not in stapes.

10 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 12: Cleft Lip and Palate

Anatomy

Anatomy of the Lip

The lip is composed primarily of muscles, covered by skin on the outer surface and mucosa on the inner surface. The lip edge or vermillion is covered by nonkeratinizing epithelium made red by numerous highly vascular connective tissue papillae. The junction between the vermillion and skin is called the mucocutaneous ridge or white line. This line forms a gentle arch in the upper lip and is depressed lightly in the middle to form the center of "cupid's bow". Lateral extension of the white line completes the cupid's bow. From the ends of this central depression of the white line, small ridges extend upward to the base of the columella enclosing a small depressed skin area called the philtrum. A slight protrusion of the vermillion below the cupid's bow is called the tubercle. These anatomic landmarks are used for orientation in repairing clefts of the upper lip (Fig. 12-1).

The lip is a movable muscular curtain composed primarily of the orbicularis muscle which creates a sphincter and is formed by significant contributions from paired muscles converging on the mouth (Fig. 12-2). The muscle substance arches around the lips and interlaces at the angle of the mouth. The muscle lies between the skin and mucous membranes of the lips, limited superiorly by the nose and inferiorly by the chin.

An almost infinite variety of movements can be obtained by the lips by the individual action, inaction, or antagonistic action of these various paired muscles.

The main arterial blood supply to the upper lip is provided by the paired superior labial arteries which are located near the mucous membrane deep to the muscle. Sensation to the upper lip is supplied mainly by fibers from the inferior orbital branches of the fifth cranial nerve. Motor fibers are derived from the labial branches of the seventh cranial nerve.

Anatomy of the Palate

The palate is composed of a bony anterior portion and a soft muscular posterior portion. The tooth-bearing alveolar ridges surround the hard palate. An anterior wedge-shaped portion of the alveolar ridge carrying the four incisior teeth and a triangular section behind constitute the premaxilla or primary palate. The remaining hard palate is made up of palatine processes of the maxillary bone, and to a lesser degree by the palatine processes of the palatine bone. The maxillary and palatine portion of the hard palate plus the soft palate constitute the secondary palate.

The oral surface of the hard palate is covered by firm mucoperiosteum of variable thickness. Anteriorly this membrane has raised ridghes called palatine rugae. The nasal surface of the hard palate is divided into two portions by the nasal septum and is lined by a thin mucoperiosteum surfaced anteriorly by stratified squamous and posteriorly by respiratory epithelium. Blood supply to the hard palate is provided chiefly by the anterior palatine artery

1 which is derived from the internal maxillary via the greater palatine foramen. The nerve supply is chiefly from the anterior palatine and nasopalatine branch from the sphenopalatine ganglion. The nerve supply follows the arterial blood supply in distribution.

The soft palate is movable muscular curtain covered on its oral surface by stratified squamous epithelium and on its nasal surface by pseudostratified columnar epithelium. This structure contains numerous muscles and glands. The palate has five muscles as shown in Table 12-1.

Table 12-1. Nerve Supply and Muscles of the Palate

Tensor veli palatini Fifth nerve Tense and depress soft palate Levator veli palatini Pharyngeal plx Elevate the palate Musculus uvulae Pharyngeal plx Draw uvula upward and forward Glossopalatine Pharyngeal plx Draw palate down and narrow pharynx Palatopharyngeus Pharyngeal plx Draw palate down and narrow pharynx

The arterial blood supply to the soft palate is the descending palatine branch of the internal maxillary, the ascending palatine branch of the external maxillary, the palatine branch of the ascending pharyngeal, the twigs from the tonsillar branch of the dorsalis linguae. The sensory nerve supply is mainly from the lesser and middle palatine branches from the sphenopalatine ganglion.

Embryology of the Cleft Lip

The central upper lip is formed by growth of the nasomedian process in a downward medial and forward direction. This process provides the central lip consisting of philtrum, labial tubercle, the central alveolar ridge containing the paired central and lateral incisor teeth, the anterior nasal septum, and an anterior palatal triangle (primary palate). Paired lateral maxillary processes grow medially toward the descending nasomedian process. These processes provide the lateral upper lip elements.

Failure of the structure to unite on one side, or both, provides clefts of the lip, extending into the nose and through the alveolus between the lateral incisor and cuspid teeth. Paired processes or shelves arise from the maxillary processes. They converge upon the primary palate, on each other, and the septum, to fuse (from front to back) to provide the secondary palate. The lip and hard palate formation is completed by the eight week of embryonic life and the soft palate and uvula are completed by the twelfth week of embryonic life.

Note: The genesis of harelip has not been agreed upon by various investigators. Some believe it is the result of failure of fusion between the maxillary and frontonasal processes. Others believe that it is the lack of "filling up" between the premaxillary and maxillary centers that results in a furrow and hence a harelip.

2 Types of Cleft Lip and Palate (Fig. 12-3)

Types of cleft lip and palate include:

1. Unilateral cleft lip: occurs in varying degrees and may involve the alveolus in a like manner.

2. Unilateral cleft lip with cleft palate.

3. Bilateral clefts of the lip: usually involve complete clefts of the secondary palate but can occur (rarely) without the presence of a cleft palate.

4. Bilateral clefts of the lip, alveolus, and palate: both nasal cavities are exposed to the oral cavity.

5. Clefts of the secondary palate: occur in varying degrees such as bifid uvula, submucous cleft, and complete division up to the primary palate.

6. Median cleft of the upper lip: very rare.

Incidence of Cleft Lip and Cleft Palate

Cleft lip with cleft palate is the most common; cleft palate alone is next; cleft lip alone is the least common. The incidence of cleft lip with or without cleft palate varies from 0.8- 1.6:1000 births. The incidence of combined cleft lip and cleft palate occurs 1.5-3 times more frequently than cleft lip alone. The incidence of cleft lip with cleft palate is greater in males. The incidence of cleft palate alone is greater in females. The frequency of single cleft lip is greater on the left than on the right side. The incidence of cleft lip is three times greater in Caucasians than in Negroes. Genetic factors in cleft lip with or without cleft palate are:

1. Mutant genes 2. Chromosomal aberration 3. Environmental teratogens 4. Multifactorial inheritance.

Incidence of Cleft Palate

Cleft palate is embryologically and genetically different from cleft lip alone or combined cleft lip and cleft palate. The rate is 0.45:1000 Caucasian births. The cleft palate is more common in females. Genetic factors in cleft palate are:

1. Mutant genes 2. Chromosomal aberration 3. Environmental teratogens 4. Mutlifactorial inheritance.

3 Counseling Parents Regarding Lip and/or Palate Clefts

Situation A

The parents are normal, the first child is affected with cleft lip with or without cleft palate.

Question 1: What are the chances for the next child if there are no affected relatives?

Answer: 4%.

Question 2: What are the chances for the next child if there is an affected relative?

Answer: 4%.

Question 3: What is the chance for the next child if the affected child has another malformation?

Answer: 2%.

Question 4: What is the chance for the next child if the parents are related?

Answer: 4%.

Situation B

Both parents are normal and have two affected children with cleft lip with or without cleft palate.

Question: What are the chances for the next child to have the same defect?

Answer: 9%.

Situation C

One parent is affected with cleft lip or cleft palate and there are no affected children.

Question: What is the chance for the next child of having a defect?

Answer: 4%.

Situation D

One parent is affected and there is one affected child.

Question: What is the chance that the next child will be affected?

Answer: 17%.

4 Counseling for Cleft Palate Alone

Situation A

The parents are normal, one child is affected with cleft palate.

Question 1: What is the chance for the next baby to have cleft palate if there are no affected relatives?

Answer: 2%.

Question 2: What is the chance for the next baby to have cleft palate if there is an affected relative?

Answer: 7%.

Question 3: What is the chance for the next baby to have cleft palate if the affected child has other malformations?

Answer: 2%.

Situation B

The parents are normal but have two children, both with cleft palate.

Question 1: What is the chance for the next baby to have a cleft palate?

Answer: 1%.

Situation C

One of the parents has a cleft palate.

Question 1: With no affected children, what is the chance of the next baby having a cleft palate?

Answer: 6%.

Question 2: What is the chance for the next baby swith one child having a cleft palate?

Answer: 15%.

5 Timing and Techniques

Lips

There is no set time for repair of cleft lip. Since cleft lip is a congenital deformity, adequate time should be allowed to properly observe and examine the infant to determine the possibility of other associated congenital defects. Closure usually is performed within 3 months; however, social pressures often dictate that the defect be closed before the infant leaves the hospital. The rule of over 10 is advocated, over 10 weeks in age, over 10 lb in weight, and hemoglobin over 10 g.

Single Cleft Lip

Defect

1. Floor of nose communicates freely with oral cavity. 2. Maxilla is hypoplastic on the cleft side. 3. Lower lateral nasal cartilages lower on cleft side in all respects. 4. Nasal columella is displaced to the normal side. 5. Cleft side of the nasal ala base is deformed. 6. Cartilaginous nasal septum is deflected. 7. Alveolar defect passes through developing dentition.

Repair

1. Millard's rotation advancement - technique is accepted by many as the standard for repair of the unilateral cleft lip. It is a cut-as-you-go technique which places the scar in a normal philtral line adding tissue to the deficient noncleft side of the lip and the cleft side of the nasal columella (Fig. 12-4).

2. Tennison's triangular flap - is designed to add tissue to the deficient noncleft side of the lip low in the lip. It is advanced as a simple to teach method with a predictable result (Fig. 12-5).

3. Le Mesurier's quadrilateral flap - was originally designed with the incision in the very midline of the lip but later was shifted toward the cleft side of Cupid's bow. This technique is perhaps the easiest to understand, teach, and obtainb a satisfactory result for the low volume surgeon (Fig. 12-6).

4. Skoog's double triangular technique - recognizes the deficiency in the noncleft side of the lip both low and high at the columella base. This technique, although difficult to conceive, provides real improvement in the nasal portion of the maxillary cleft (Fig. 12-7).

6 Bilateral Cleft Lip

Defect

1. Floor of the nose is missing on both sides and the nasal and oral cavities communicate freely. 2. Central portion of the alveolar arch is rotated forward and upward out of the area. 3. Prolabium skin for the lip is underdeveloped. 4. Columella is short. 5. Central portion of the lip contains no lip muscle or lip vermillion.

Repair

1. Single stage repair is often greatly appreciated by the family since a horrendous defect is converted to a continuous lip with a much improved nose (Fig. 12-8). The single stage bilateral lip closure is often the cause of tremendous secondary defects which require major secondary repair.

2. Staged bilateral lip closure 3 months apart using techniques for single cleft lip repair have come into favor since the premaxilla is more readily controlled by using the lip as an orthodontic device and the lip repair can add tissue to the columella, hopefully avoiding serious secondary defects of the lip and nose. Some surgeons prefer to do a lip adhesion technique first to help control the alveolar arch segment and then proceed with the primary lip repair.

Alveolar Arch

The alveolar arch is completely separated in the single cleft lip defect. To obtain osseous continuity, the epithelial tissue must be removed from the opposing alveolar surfaces and a force provided to bring them together. Epithelial tissue is removed and hinged upward to form the floor of the nose. The lip closure provides the necessary orthodontic force. With proper timing of the lip surgery, preoperative dental orthodontic appliances have been found unnecessary by most surgeons.

Maxillary growth and dental arch malalignment, secondary to scar contracture following primary closure, are factors which have influenced timing of the procedures. Simple closure of the lip without muscle approximation plus closure of the soft palate portion of the complete cleft palate have been advocated. Dental appliances adjusted frequently to accomodate the growth serve to cover the osseous portion of the remaining cleft defect. The defect of the hard palate is closed after optimum maxillary and alveolar arch growth has occurred. Redirection of the fibers of the orbicularis oris muscle displaced by the cleft has received increased attention in repair of primary clefts.

Hard and Soft Palate Cleft Repairs

Following repair of the cleft lip, including the nose, the patient with a complete cleft is left with a midline cleft of the hard palate extending from about the canine area all the way back including the uvula. This is true for both single and double clefts. The only major

7 variable is the position of the vomer. Techniques designed to correct clefts of the palate only are used for closure of the primary cleft and those present following lip repair.

The timing for closure of the cleft palate is less variable than that for the lips. The most popular time is 18 months. The time of cleft palate closure is very important in the development of speech, hearing, swallowing, dental occlusion, and facial growth.

Techniques

1. Von Langenbeck's: Bilateral relaxing incisions are performed with freshening of the cleft margins. The bipedicle oral mucoperiosteal flaps are elevated. The nasal mucoperiosteal layer is elevated and the cleft is closed in two layers with a third layer in the soft palate muscles.

2. V-Y retropositioning (Wardill-Kilner): Bilateral relaxing incisions are performed. The anterior part of each relaxing incision is angled backward toward the midline to form a W. The cleft edges are incised. The oral mucoperiosteal flaps are elevated to the posterior border fo the hard palate. The nasal layer is elevated and the cleft is closed in two laters, with a third layer in the soft palate muscles. The oral mucoperiosteum is anchored to the unelevated anterior tip of the oral mucoperiosteum.

3. Dorrance's: Bilateral relaxing incisions are performed and continued around behind around behind the anteior teeth to meet each other. The entire oral mucoperiosteum is elevated back to the posterior border of the hard palate. Margins of the cleft are incised between the nasal and oral layers. The oral mucoperiosteum is returned to the hard palate about 1-2 cm distal to its original position and anchored by passing sutures through holes drilled in the hard palate. This oral mucoperiosteal flap is best used when the cleft does not extend too far forward in the bony hard palate.

4. Vomer flap: In both single and bilateral clefts of the hard palate, flaps from the vomer may be elevated laterally to be joined with flaps from the lateral nasal aspect of the cleft. Closure of the hard palate defect in complete clefts may be performed with the lip surgery. The usual time is age 10-18 months as a separate procedure and the soft palate is closed shortly thereafter. Great controversy exists regarding timing of closure of the hard palate defect, its relation to the maxillary arch growth, and development of orthodontic problems. Some surgeons close the soft palate early and delay closure of the hard palate to avoid affecting maxillary bone growth.

Various Flaps Associated with Treatment of Cleft Lip and Palate Problems

Including Velopharyngeal Insufficiency

Abbe's

Abbe's technique is a lip switch flap based on the coronal (labial) artery and used to correct defects of up to 50% of either lip. It is used mostly for late correction of defects of the upper lip following bilateral cleft lip repair.

8 Millard's Forked Flap

The Millard's forked flap technique utilizes scars of the upper lip to lengthen the columella and raise the tip of the nose in cases of previously repaired bilateral cleft lip.

Ecker's Buccal Flaps

This technique is used in primary cleft lip repair and in secondary lengthening procedures to reduce the side-to-side tightness of the soft palate by bringing tissue in from the buccal area.

Dorrance's Palatal Flap

This is an incision along the palatal border of the maxillary teeth for raising the mucoperiosteum of the entire palate in both primary and secondary palate procedures.

Wardill's V-Y Flaps

This incision is similar to the Dorrance incision but angles backward to the midline in the cuspid region.

Langenbeck's Bipedicle Flap

This is similar to the Wardill incision but stops at the cuspid area. Is used as a primary relaxing incision for cleft palate repair.

Pharyngeal Flap

1. An inferiorly based flap may be used for additional tissue in closure of primary clefts of the soft palate. It may be used to decrease hypernasal speech in short or paralyzed palates.

2. A superiorly based flap is used in conjunction with palatal lengthening procedures requiring placement of the mucosal lining or nasal resurfacing of a retropositioned palate. The flap also can be used after a midline splitting of the soft palate, and using the superiorly based pharyngeal flap as a means of closing the nasal portion of the split palate it provides skin lining for the undersurface. The oral surface of the soft palate is closed over the pharyngeal flap. This provides bilateral ports in the area leading to the nasopharynx.

3. Hynes' pharyngoplasty has crossed vertical flaps on the posterior pharyngeal wall to build up a contact pad for the soft palate on phonation.

4. A transverse pharyngeal flap, designed to preserve the superior constrictor muscle innervation and prevent atrophy which has been observed when the Hynes' pharyngoplasty has been performed. The technique includes making a split in the soft palate for visualization and utilization of the crossed flaps for lining the nasal surface of the split soft palate.

9 Cronin's Nasal Flap

The mucoperiosteum covering the nasal suface of the hard palate posteriorly is carried backwards along the oral mucoperiosteum in palatal lengthening procedures. This tissue provides nasal epithelial covering for the retropositioned soft palate.

Island Flap (Millard's)

This is a cut section of the anterior hard palate mucoperiosteum still attached to the greater palatine artery. This flap is turned over and sutured to the nasal raw area created by the palatal pushback procedure.

Smith's Nasopharyngeal Pushback

The lateral wall of the nasopharynx directly behind the hard palate overlying the medial surface of the medial pterygoid plate is elevated widely and incised up to the base of the skull to provide accommodation in the pharynx for retropositioning of the soft palate making repeat pushback procedures possible.

Smith's Double Palatal Pushback

The Smith's double palatal pushback was designed for those patients in whom a one- stage operative procedure selected to provide maximum benefit was deemed inadequate. Operation 1 consisted of either a Dorrance's or Wardill's palatal pushback combined with Cronin's nasal flap and a nasopharyngeal pushback. Operation 2 6-9 months later, consisted of a repeat Dorrance's or Wardill's palatal pushback with repeat nasopharyngeal pushback combined with a superiorly based pharyngeal flap. In operation 1 the greater palatine arteries were freed from the undersurface of the oral mucoperiosteal flap for a distance adequate to allow 2 cm of retropositioning of the soft palate. The arteries were transected at the time of operation 2.

Smith's Nasopharyngoplasty (Third Faucial Arch) Technique

The Smith's nasopharyngoplasty was designed to improve velopharyngeal competence in patients with palatal paralysis and those unsuccessfully repaired by other techniques or those patients in whom pharyngeal flaps were unsuccessful or found inadequate to reach the shrunken and scarred soft palate remnant. The procedure consists of a transpalatal approach to reach the superior nasopharynx and detach the entire superior portion of the superior constrictor muscle from the base of the skull and pull it down to the lower border of the soft palate. As the muscle is mobilized it can be pulled downward in a draping manner so that the upper central portion anteriorly remains attached only to the soft palate. The muscle is closed upon itself starting inferiorly leaving a central opening at the upper undersurface of the soft palate less than 1 cm in diameter. The closure in effect produces a third faucial arch and nasalizes the eustachian tubes. The potential space laterally and posterior to the displaced muscle cone granulates in.

10 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 13: Facial and Airway Trauma

General Considerations

1. Generally, facial fractures are not life threatening and have a relatively low priority in the management of the multiple-injured patient. However, these fractures may be the source of airway obstruction and hemorrhage which may make their management more urgent.

2. Definitive reduction of facial fractures should be performed within 7-10 days of injury. The exact timing will depend on the patient's overall suitability for general anesthesia, the amount of swelling, as well as other injuries. If the patient is to have surgery for repairing injuries elsewhere in the body, every effort should be made to repair the facial fractures at that time to avoid repetitive general anesthetics.

3. When transportation is necessary, and if other injuries permit, the patient should be placed in the prone position to allow drainage of blood and saliva out of the airway and also prevent collapse of the tongue into the airway. Intubation or tracheostomy may be indicated before transport is undertaken.

4. Cervical spine films should be considered in patients with facial fractures since the force which caused the facial fracture may potentially injure the cervical spine.

Nose

Anatomy

The nasal bones are paired structures which are attached superiorly to the frontal bone, laterally to the maxilla, and medially to each other. The paired upper lateral cartilages attach to the inferior border of the nasal bones. The bony septum (perpendicular plate of the ethmoid) is related posteriorly. The lower two-thirds of the nose is supported by the paired upper and lower lateral cartilages as well as the cartilaginous septum (quadrilateral cartilage). The vomer forms the posterior inferior portion of the septum.

Blood is supplied to the nose by the internal and external carotid arteries. The arteries derived from the external carotid are the nasopalatine, sphenopalatine and greater palatine (branches of the internal maxillary), and septal (branch of the facial). The internal carotid supply is by way of the ophthalmic artery and its branches, the ethmoid arteries, and the dorsal nasal artery.

Internally, the nerve supply to the nose is from the internal nasal branches of the anterior ethmoidal ganglion and branches from the sphenopalatine ganglion. Externally, the upper part of the nose is supplied by the supratrochlear and infratrochlear nerves; the external nasal branch of the anterior ethmoidal and the infraorbital nerve supply the lower part of the nose.

1 Signs and Symptoms

1. Pain and tenderness 2. Epistaxis 3. Nasal congestion 4. Ecchymosis and swelling which may also include the periorbital area 5. Deformity - may be difficult to recognize initially because of swelling.

X-rays

Anteroposterior, lateral, and submental vertex views should be obtained.

Treatment

1. All patients with a question of nasal fracture should be examined for a septal hematoma which should be drained immediately.

2. Reduction is indicated when there is a bony deformity or an airway obstruction secondary to a bone deformity.

3. Significant swelling should be allowed to subside before reducing the fracture to achieve a more accurate result. This usually takes 3-5 days.

4. Closed reduction is the treatment of choice for most nasal fractures. Anesthesia is achieved with topical cocaine intranasally and lidocaine infiltrated sparingly over the dorsum and in the area of the infraorbital foramen. A splint will help protect the reduced fracture and reduce the amount of edema.

5. Open reduction is indicated in a multiple-comminuted fracture which cannot be managed by closed reduction. This is accomplished through an H-like incision in the area of the nasion and wiring the fragments in the position.

Nasofrontal Ethmoidal Complex Fractures

These are unusual but more serious injuries with involvement of the nasal and frontal bones which are displaced into the ethmoid labyrinth. There may be associated injuries of the lacrimal system, medial canthal ligaments, and dura with CSF leakage. Physical examination reveals marked posterior displacement of the nose, and x-rays confirm the involvement of the frontal sinus. In addition to repair of the associated injuries (including obliteration of the frontal sinus), the nasofrontal area must be held in a reduced position. Lead or Silastic plates placed on both sides of the nasal bones with transnasal wiring has been used in the past. A better technique employs an acrylic external fixation device which is attached laterally to the frontal bone and mediallly to the fracture area.

2 Complications

1. Untreated septal hematoma may lead to abscess with loss of quadrilateral cartilage and dorsal depression. 2. Unrecognized, untreated displaced fracture will lead to deformity. 3. Untreated mucosal lacerations may lead to synechia and stenosis. 4. Untreated septal fracture or dislocation may lead to nasal obstruction.

Mandible

Anatomy

The mandible is a horseshoe-shaped bone which contains the lower teeth. It is attached to the skull by a sliding-binge (ginglymoarthroidal) joint in the glenoid fossa of the temporal bone. The inferior alveolar nerve (third division of cranial nerve V) and artery enter the mandible through the mandibular foramen on the medial aspect of the ramus. They exist through the mental foramen (the weakest point of the mandible) to supply the chin and lower lip. The mandible may be divided into various anatomic areas which are outlined in Fig. 13-1. The frequency of fractures in each area is noted.

Figure 13-1. Frequencies of fractures of the mandible

Condyle 36% Coronoid 2% Ramus 3% Angle 20% Alveolar 3% Body 21% Parasymphyseal 14% Symphyseal 1%.

Major Muscles of Mastication

1. Temporalis

a. Nerve: mandibular division of the fifth cranial nerve. b. Arises from the floor of the temporal fossa. c. Attachment is to the coronoid process of the mandible. d. Action: powerful elevator of mandible.

2. Masseter

a. Nerve: mandibular division of the fifth cranial nerve. b. Arises from the lower and medial border of the zygomatic arch. c. Attachment to the mandible is the lower one-half of the lateral surface. d. Action: powerful elevator of mandible.

3 3. Internal pterygoid (medial pterygoid)

a. Nerve: mandibular division of the fifth cranial nerve. b. Arises from the medial surface of the lateral pterygoid plate and tuberosity of the maxilla. c. Attachment is to the lower one-half of the mandible on the inner surface. d. Action: to pull the mandible upward, inward, and forward.

4. The external pterygoid (lateral pterygoid)

a. Nerve: mandibular division of the fifth cranial nerve. b. Arises from the lateral surface of the lateral pterygoid plate and from the greater wing of the sphenoid. c. Attachment is to the inner and anterior aspect of the neck of the condyle. d. Action: to pull the mandible forward.

Depressors of the Mandible

1. Geniohyoid

a. Nerve: hypoglossal. b. Attachment is to the genial tubercle at the mandibular symphysis. c. Action: to open the mouth.

2. Digastric (anterior belly)

a. Nerve: mandibular division of the fifth cranial nerve. b. Attachment is to the lower border of the mandible near the midline. c. Action: to open the mouth.

3. Mylohyoid

a. Nerve: mandibular division of the fifth cranial nerve. b. Attachment is to the mylohyoid ridge of the mandible and to the hyoid bone. c. Action: raises the hyoid bone as well as opens the mouth.

To open mouth: The lateral pterygoid pulls the condyle forward while the digastric, mylohyoid and geniohyoid depress the jaw.

Muscles attached to the lateral side of the mandible include: The masseter, part of the temporalis on the coronoid, and the lateral pterygoid muscle on the condyle.

Muscles attached to the lateral side of the mandible include: The digastric, mylohyoid, medial pterygoid, temporalis, and lateral pterygoid on the neck of the coronoid.

Fractures of the mandible may be described as favorable or unfavorable (Fig. 13-2). Favorable fractures are those in which the muscles of mastication help hold the fragments in

4 place, whereas unfavorable fractures tend to be displaced by the muscular forces acting on the mandible.

The temporomandibular joint is innervated by the masseter and auriculotemporal nerves. The meniscus that separates the upper cavity from the lower cavity is made of fibrocartilage. The three ligaments which attach to this area are the (1) temporomandibular, (2) stylomandibular, and (3) sphenomandibular. The tubercle of the zygomatic process of the temporal bone helps hold the condyle in position.

There are 20 deciduous teeth which begin to appear at 6 months of age, and all have erupted by 24 months. Permanent teeth begin to appear at 6 years and all 32 have erupted by age 24. The angle of the mandible measures slightly more than 90° in the young and becomes more obtuse with increasing age and loss of dention.

Signs and Symptoms

1. Maloccclusion: perhaps one of the most sensitive indicators of a fracture. The displacement may be great enough that it is noted on inspection, or only the patient may be able to notice it when he tries to achieve normal occlusion.

2. Trismus: the patient will have pain on moving the mandible (such as opening the mouth) as this causes movement of the fracture fragments.

3. Swelling, ecchymosis, and intraoral lacerations may be present.

4. Palpable displacement may be noted externally or by palpating intraorally.

5. Mental nerve hypesthesia may be present if the inferior alveolar nerve has been injured by the fracture.

6. Look for more than one fracture. Since the mandible is firmly attached to the base of the skull, it is (more or less) a ring (much like the pelvis). Consequently, to displace a fracture, the mandible must be able to move at some other point, which is commonly another fracture.

X-Rays

1. Antero-posterior view: good for ramus and condylar fractures. 2. Lateral views (or even better, oblique views): good for condyle, angle, and body. 3. Panorex (orthoplanography): not always available, but good for condyle, ramus, and body, as well as associated injuries to the teeth. 4. Occlusal: good for symphyseal fractures.

Treatment

1. Initial therapy includes a complete evaluation of the patient. The airway may be compromised by blood, secretions, or the tongue. Since the mandible provides support for the tongue, a severe fracture (such as a bilateral body fracture) may allow the tongue to fall back

5 into the airway causing dyspnea. This can be managed quickly by grasping the tongue with a towel clip and pulling it forward.

The patient can be made more comfortable by temporarily immobilizing the mandible by use of a Barton's dressing (gauze wrapped around the vertex of the head and under the mandible). Also, a wire can be secured around a stable tooth on each side of the fracture.

2. When the patient has a normal or near normal dentition:

a. Symphysis: If undisplaced, intermaxillary fixation only. If severely displaced, then open reduction and wiring may be necessary.

b. Body: Generally, intermaxillary fixation alone is necessary.

c. Angle: If undisplaced, intermaxillary fixation alone. If displaced, open reduction and internal fixation.

In all of the above fractures, even if some displacement is present, closed reduction and intermaxillary fixation can be attempted for a week. If the results are unsatisfactory, then open reduction with wiring can be performed.

d. Ramus: Intermaxillary fixation alone.

e. Condyle: Unilateral - may require no therapy other than a soft diet.

Bilateral - intermaxillary fixation. If proper occlusion cannot be achieved, the open reduction and fixation may be necessary.

f. Coronoid process - no therapy indicated. Not infrequently, there is an associated zygomatic arch fracture.

3. When the patient is edentulous, the patient's dentures can be used to achieve intermaxillary fixation by wiring the upper denture to the alveolus, pyriform aperture, or the zygomatic arch. The lower denture can be stabilized to the patient by circummandibular wiring. The two dentures are held in occlusion by wiring together arch bars placed on the dentures before surgery. Gunning splints can be fabricated from impression if the patient's dentures are not available.

Most fractures (except coronoid and unilateral condyle fractures) must be openly reduced and wired. This is particularly true in bilateral condylar fractures in the edentulous patient.

4. In pediatric fractures, open reduction is rarely required. Furthermore, the period of intermaxillary fixation is much shorter than in adults because children are more susceptible to ankylosis of the temporomandibular joint than adults.

5. Dislocation of the mandible occurs when the condyle is displaced anterior to the tubercle of the zygomatic arch. The patient has an obvious open-bite deformity with pain.

6 This can be managed by placing gauze over the molars and placing the fingers under the mandible with the thumbs on the gauze covered molars. By pushing inferiorly and posteriorly, the mandible can be rocked back to its normal position. Injection of a local anesthetic into the pterygoid muscles, or intravenous muscle relaxants, may help in the reduction.

Complications

1. Nonunion: May result from a number of factors including infection, lack of adequate immobilization, and inadequate approximation of fragments. 2. Ankylosis of temporomandibular joint: Due to prolonged intermaxillary fixation. 3. Permanent anesthesia of mental nerve. 4. Malunion: Occurs when fragments are improperly aligned. 5. Failure to diagnosis multiple fractures.

Zygoma

Anatomy

The zygoma provides prominence to the lateral side of the face. It has attachments to three other bones of the skull: the frontal bone, the maxilla, and the zygomatic process of the temporal bone. When these three attachments are injured, this gives rise to the "trimalar" or "tripod" fracture. Additionally, it forms part of the floor of the orbit (roof of the maxillary sinus) and provides an attachment for the lateral suspensory ligament of the eye.

Signs and Symptoms

1. Periorbital ecchymosis and swelling. 2. Depression of the cheek - this may be difficult to detect initially because of swelling. 3. Tenderness and palpable separation (step-off) at the fracture site. 4. Either proptosis or enophthalmus may be present initially. 5. Hyperesthesia of the upper lip may indicate involvement of the infraorbital nerve. 6. Trismus may be present if the depressed zygomatic arch is impinging on the temporalis muscle or the coronoid.

X-Rays

1. The Waters' view is probably the best single view for diagnosing malar fractures. In addition to the fractures there generally will be opacification of the antrum. The Caldwell's view demonstrates the zygomaticofrontal suture area nicely and the submental vertex ("bucket handle") view will demonstrate fractures of the zygomatic arch.

Treatment

Gillies' Approach

A small incision is made in the skin under the sideburn and an elevator is passed deep to the temporal fascia (which attaches to the zygomatic arch). This approach is excellent for

7 isolated fractures of the zygomatic arch which generally require no further stabilization to maintain the reduction. This approach also may be used to help mobilize trimalar fractures.

Keen's Approach

Essentially the same as the Gillies', but through an intraoral incision above the molar teeth.

Transantral Approach

The maxillary sinus is entered through the anterior wall (like a Caldwell-Luc procedure) and the malar fracture is reduced by placing a strong elevator in the lateral recess of the maxillary sinus. The undersurface of the orbital floor is explored through the antrum and the overall reduction maintained by placing gauze packing in the sinus. This is removed 10 days postoperatively through a nasoantral window created at the time of the initial surgery. This technique is excellent for multiple comminuted fractures.

Pinning Techniques

The reduction is achieved by manipulating the zygoma with bone hooks and then maintained by passing a Steinman's pin through the zygoma and into the palate. The pin is removed 6 weeks later.

Open Reduction

The infraorbital rim and frontozygomatic fractures are explored through infraorbital and eyebrow incisions, respectively. Reduction is maintained by wiring the fragments in place. This approach allows for the most accurate realignment of fragments and the best exposure for exploration of the orbital floor.

Complications

1. Failure to recognize the fracture because of edema. 2. Failure to recognize and treat the accompanying orbital floor fracture leading to enophthalmos. 3. Permanent anesthesia of the infraorbital nerve. 4. Malunion due to improper alignment of fragments. 5. Fracture of the skull by applying excessive pressure when using the Gillies' approach. 6. Blindness due to hemorrhage into orbit, excessive retraction on globe during surgery, or packing bone fragments into the globe during the antral approch.

8 Orbit

Anatomy

The orbital floor is a sheet of thin bone composed primarily of a portion of the maxilla witgh contributions from the zygoma and the palatine bone. It transmits the infraorbital nerve and vessels which exit through the infraorbital foramen below the inferior orbital rim.

Pure "blowout" fractures which involve the orbital floor without injury to the inferior orbital rim are unusual. The proposed mechanicm of injury is direct pressure applied to the globe which is displaced posteriorly with a subsequent increase in intraorbital pressure. The orbit "blows out" at its weakest points, most commonly the posteromedial portion of the orbital floor. However, other portions of the orbital floor as well as the medial wall may be involved.

Impure blow-out fractures occur when the orbital rim is involved and may occur as an isolated injury or in conjunction with a fracture of the zygoma (trimalar) fracture.

In any injury that involves the orbital floor, orbital contents may be displaced into the maxillary sinus or trapped in the fracture line giving rise to a variety of symptoms.

Signs and Symptoms

1. Diplopia (primarily an upward gaze): This may be related to edema or entrapment of the inferior rectus (or less commonly the inferior oblique) muscle in the fracture line thereby tethering upward movement of the globe. The best test for entrapment is the forced duction test in which topical anesthesia is applied to the conjunctival sac and then the sclera is gently grasped at the insertion of the tendon of the inferior rectus muscle. If not entrapped, the globe should rotate freely whereas limitation of passive upward movement may indicate indolvement of the inferior rectus muscle.

2. Enophthalmos: Inward displacement of the globe may not be appreciated initially because of periorbital swelling and may be only noticeable a few days after the injury. The enophthalmos is caused by displacement of orbital fat into the maxillary antrum, or in the case of a medial blowout fracture, the ethmoid sinuses.

3. Nasal bleeding.

4. Hypesthesia of the upper lip due to involvement of the infraorbital nerve.

X-Rays

1. The Waters' view may show the herniation of orbital contents into the superior portion of the antrum as well as the fracture.

2. Tomograms of the orbit will more clearly delineate the extent of the fracture.

9 Treatment

Treatment varies with the severity of injury. Generally, if there is evidence of loss of orbital contents, entrapment, or a large dehiscence on tomograms, then the floor should be explored. Although the floor may be inspected and even packed into position through a transantral approach, a direct approach through the infraorbital skin provides for direct inspection and reduction of entrapped orbital contents as well as an opportunity to reconstruct a large defect. A variety of materials have been used to repair the defect and include cartilage, bone, Silastic, Teflon, and even Gelfilm.

Complications

1. Enophthalmos secondary to inadequate reduction of orbital fat. 2. Extrusion of graft used to reconstruct orbital floor. 3. Blindness secondary to impingement of graft on the optic nerve or excessive retraction of globe during surgery. 4. Scarring of orbital muscles leading to muscular imbalance. 5. Permanent anesthesia of the infraorbital nerve.

Maxilla

Anatomy

The paired maxilla contain the upper teeth and the maxillary antra. The nasal bones are attached medially and the attachment to the zygom laterally provides support. The blood supply is by way of the internal maxillary artery and innervation is provided by the second division of the fifth cranial nerve.

LeFort, a Frenchman, established three distinct patterns of injury in experiments performed with cadaver skulls (Fig. 13-3). Although his descriptions are widely used today, it should be recognized that the forces involved in a high-speed motor vehicle accident or other trauma today are different from the mechanisms of injury used by LeFort. Consequently, maxillary fractures may not necessarily follow the "classic" lines of LeFort. Most LeFort fractures are bilateral, but may not be the same on each side.

1. LeFort's I (Guerin fracture): A transverse fracture above the apices of the upper teeth.

2. LeFort's II (pyramidal fracture): It is important to note that this is the only LeFort fracture that involves the inferior orbital rim. As with the LeFort's I, the zygomatic arch is not involved.

3. LeFort's III (craniofacial dysjunction): The entire midface is separated from all of its bony attachments to the skull. The zygomatic arch is involved.

10 Signs and Symptoms

1. Marked swelling and ecchymosis. 2. An elongated, depressed "dish-shaped" appearance of the face. 3. Nasal bleeding. 4. CSF rhinorrhea. 5. Palpable depression in the area of the fractures. 6. The upper alveolus should be grasped and tested for mobility. If the fracture is firmly impaced mobility may not be present. 7. Blindness may be present.

X-Rays

Fractures may be noted on all facial films although the Waters', Caldwell's, and submental vertex views may be most helpful. Anteroposterior and lateral tomograms of the midface should be performed to better delineate the fractures.

Treatment

1. Initial treatment consists of a complete evaluation of intracranial, as well as chest, abdominal, and extremity injuries. The airway may be compromised such that intubation or tracheostomy is required. Once stabilized, the patient is a candidate for repair of the facial injuries.

2. The general principles of repair of LeFort fractures are proper alignment and stabilization. Intermaxillary fixation provides support from the mandible and proper alignment of the midface. If there are insufficient teeth for intermaxillary fixation, the patient's dentures or fabricated splints will be necessary. This should be accomplished before proceeding to suspension of the midface to a stable point superiorly, otherwise malocclusion may occur.

3. LeFort's I: After intermaxillary fixation is accomplished with arch bars, circumzygomatic wires are passed (since the zygomatic arch is not fractured) and attached to the arch bars. Alternatively, the fracture fragments may be wired directly thereby eliminating the need for circumzygomatic wire.

4. LeFort's II: Since the zygomatic arch is intact, intermaxillary fixation and placement of circumzygomatic "drop wires" is the treatment of choice. The nasal and inferior rim fractures may require direct wiring.

5. LeFort's III: Intermaxillary fixation should be accomplished first. Since the zygomatic arch is involved, a more superior point of stabilization is used (generally the frontal bone). In addition to a drop wire from this area, the lateral orbital rim fracture should be wired directly.

11 Complications

1. Malocclusion by improper intermaxillary fixation. 2. Telecanthus because of untreated medial canthal ligament injury. 3. Inadequate treatment because the severity of injury is not recognized. 4. Enophthalmos due to an inadequately treated orbital component.

Frontal Sinus

Anatomy

Located between the inner and outer tables of the frontal bone, the frontal sinus varies greatly in size and may be unilaterally or bilaterally absent. The sinus usually is separated into at least two unequal sections by one or more vertical septa. Drainage is by way of the nasofrontal duct ostia which variably end in the nose or ethmoid sinus.

Signs and Symptoms

1. Pain and tenderness. 2. Swelling and ecchymosis (may include periorbital area). 3. Epistaxis and CSF rhinorrhea. 4. Fracture may be palpable through lacerations in the area. 5. May be associated with a nasal fracture (nasofrontal ethmoid fracture) as well as skull fractures.

X-Rays

Caldwell's and lateral views of skull should be done. Tomograms should be used to evaluate any posterior wall and nasofrontal duct involvement. Frequently the fractures are more severe than appreciated radiographically. Computerized axial tomography should be performed to rule out intracranial injuries.

Treatment

Anterior Wall Only

Nondisplaced fractures require no treatment. Displaced fractures may be elevated through an existing laceration or a surgical incision and wired in place if unstable. Occasionally, the fracture must be reduced through an osteoplastic flap and stabilized with wiring or Gelfoam packing of the sinus.

Posterior Wall Involvement

The frontal sinus should be explored through an osteoplastic flap. The dura must be explored and repaired if dehiscent. Since the integrity of the posterior wall is lacking, the patient will be at risk of serious intracranil complication if a upper respiratory tract infection or frontal sinusitis should develop. Consequently, the sinus should be obliterated with abdominal fat following removal of all mucosa.

12 Nasofrontal Ostia Involvement

Since scarring and stenosis of the ostia may lead to an increased risk of frontal sinusitis and mucocele development, the patient should be managed aggressively. The frontal sinus should be explored through an osteoplastic flap, and following removal of all mucosa, obliterated with abdominal fat.

Complications

1. Depression of frontal bone due to inadequate treatment or loss of bone. 2. Meningitis or brain abscess due to lack of repair of dura. 3. Chronic frontal sinusitis or mucocele development due to obstruction of nasofrontal duct.

Larynx and Trachea

Trauma to the larynx and trachea is occurring with increasing frequency. The most obvious injuries occur with penetrating (gunshot and stab) injuries of the neck. However, blunt trauma may cause severe injuries with minimal external signs of trauma. Many patients will not survive the initial injury and die before reaching the hospital, whereas some patients with quire severe injuries initially may have minimal symptoms. The early treatment of laryngeal and tracheal injuries is essential for a successful outcome.

Anatomy

The anatomy is reviewed in Chap. 15, The Larynx.

Signs and Symptoms

1. Laryngeal pain. 2. Dysphonia or aphonia. 3. Airway obstruction: May not be present initially, but may develop rapidly. 4. Hemoptysis. 5. Dysphagia and odynophagia. 6. Ecchymosis over the area of blunt injury. 7. Loss of laryngeal landmarks: Inability to delineate the laryngeal framework due to soft tissue swelling or fractures of the thyroid and cricoid cartilages. Crepitus may be present. 8. Subcutaneous emphysema. 9. Air or saliva leakage from a penetrating wound.

Diagnosis

1. Indirect laryngoscopy: Hemorrhage, mucosal lacerations, and internal deformity can be recognized. 2. X-rays of the neck and chest (AP and lateral): Computerized axial tomography may also prove useful. 3. Direct laryngoscopy, bronchoscopy, and esophagoscopy: Esophageal injuries may occur with both blunt and penetrating tracheal injuries.

13 Treatment

1. Maintain the airway. Severe mucosal lacerations and swelling may make endotracheal intubation difficult and dangerous as passage of the endotracheal tube into a false lumen may further compromise the patient's condition. A tracheostomy may be required. In laryngeal injuries, a high tracheostomy should be avoided.

2. Laryngeal trauma may be overlooked in the patient with multiple injuries. Early diagnosis and management is essential to prevent later complications.

3. Exploration of the larynx and trachea, which should be performed as soon as possible, is accomplished through a U-shaped apron flap. All laryngeal injuries as well as almost all tracheal injuries can be managed through this incision. Furthermore, the carotid sheath can be explored easily.

4. Closed reduction by "ironing out" the laryngeal cartilages over a laryngoscope should not be performed.

5. The interior of the larynx is explored through a midline laryngofissure. Mucosal lacerations are approximated with absorbable sutures, while the cartilage fractures and the laryngofissure are stabilized with stainless steel wire or non-absorbable sutures.

6. The use of stents and grafts is somewhat controversial. Most authorities use stents, but these vary from "hard" endotracheal tubes to "soft" finger cots filled with latex sponge. Also, the recommended period that the stent should be left in place varies from a few days to several weeks. Skin and mucosal grafts have been used successfully particularly when there has been a significant laryngeal mucosal loss.

7. Whenever possible, tracheal injuries should be repaired primarily. Closure of simple lacerations may suffice, or resection of a severely injured area with anastomosis and appropriate tracheal and laryngeal mobilization may be indicated. If the patient's condition is not stable, then a tracheotomy tube can be placed through the injury and definitive repair performed at a later time.

Complications

1. Stenosis of larynx or trachea due to inadequate treatment at the time of injury. 2. Hoarseness secondary to vocal cord paralysis or deformity. 3. Aspiration due to an incompetent glottis.

14 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 14: Nose and Sinuses

Embryology of the Nose (see also Chap. 11)

Anatomy

A. External Nose

Bony framework of the external nose consists of:

1. Nasal bone 2. Frontal process of the maxilla 3. Nasal process of the frontal bone.

Cartilaginous framework of the external nose consists of:

1. Lower lateral (greater alar), right and left. 2. Quadrilateral cartilage of the septum. 3. Upper lateral (lateral nasal), right and left. 4. Lesser alar, right and left. 5. Sesamoid.

Muscles of the external nose are:

1. Nasalis (constrictor). 2. Depressor septi (constrictor). 3. Procerus (dilator). 4. Dilator naris (dilator). 5. Angular head of the quadratus labii superioris (dilator). 6. Depressor alaeque nasi (constrictor).

Arterial blood supply is from:

1. External carotid artery.

Facial artery:

a. Lateral nasal. b. Angular. c. Alar. d. Septal. e. External nasal.

1 2. Internal carotid artery.

Ophthalmic artery:

a. Dorsal nasal.

Lymphatics: Via anterior facial vein to submandibular nodes.

Sensory innervation is the trigeminal nerve through:

1. Ophthalmic division.

a. Nasociliary. b. External nasal. c. Infratrochlear.

2. Maxillary division:

a. Infraorbital.

B. Internal Nose

1. The roof of the nose is formed by the cribriform plate of ethmoid bone (most of the roof), the frontal bone anteriorly, and the sphenoid bone posteriorly.

2. The nasal septum consists of:

a. Septal cartilage. b. Vomer. c. Perpendicular plate of the ethmoid. d. Maxillary crest. e. Premaxilla.

3. There are three turbinates arising from the lateral wall. The inferior turbinate is the largest. The mucous membrane covering this structure is thick and contains numerous venous plexus forming a cavernous erectile type of tissue. The bony portion connects the palatine bone, the ethmoid bone, the maxilla, and the lacrimal bone. The middle turbinate is the second largest and lies above the inferior turbinate. The mucous membrane is similar to that found in the inferior turbinate. It is actually a bony projection of the ethmoid bone. The superior turbinate is the smallest of three turbinates having a much thinner mucous membrane. This is also a projection of the ethmoid bone. The supreme turbinate is occasionally found and is extremely small.

4. There are three meatus in the lateral wall of the nasal cavity:

a. Inferior meatus: Nasolacrimal duct opens here. Damage to the nasolacrimal duct can be minimized by avoiding damage to the attachment of the inferior turbinate. The orifice of

2 the duct is located on the lateral wall from 3-3.5 cm behind the posterior margin of the nostril.

b. Middle meatus: There are two prominent objects in view in the outer wall of the middle meatus, namely the convex surface of the bulla ethmoidalis and immediately beneath it the well-defined curved margin of the uncinate process of the ethmoid. Between these two structures there is a narrow interval, the semilunar opening or hiatus semilunaris; this opening serves as a communication between the middle meatus and the small channel or canal named the ethmoidal infundibulum.

The anterior ethmoid, maxillary, and frontal sinuses drain into the ethmoidal infundibulum. The frontal sinus and anterior ethmoid cells usually drain into the anterior upper portion, and the maxillary sinus drains posteriorly to the frontal sinus. Accessory ostia of the maxillary sinus are present in 30-40% of all sinuses.

c. Superior meatus: Posterior ethmoid sinus opens here.

d. Supreme meatus: Occasionally present.

e. Sphenoethmoidal recess: Sphenoid sinus drains into the sphenoethmoid recess above and behind the superior turbinate. The ostium is usually in the posterior wall of the recess. The large opening of the sinus in the base of the sphenoid is partially enveloped by a scroll- like bone, the sphenoidal concha or turbinate (bone of Bertin).

5. Arterial supply:

a. Internal carotid artery.

Ophthalmic artery:

1) Anterior ethmoid: Anterosuperior portion of septum and lateral wall. The anterior ethmoidal is the second largest vessel supplying the internal nose.

2) Posterior ethmoid: Septum and lateral wall superiorly.

b. External carotid artery.

Internal maxillary artery:

1) Sphenopalatine: Most of the posterior part of the nasal septum and most of the lateral wall of the nose, especially posteriorly.

a) Nasopalatine (posterior septal): Roof, septum, and floor.

2) Descending palatine: Lateral wall posteriorly.

3) Pharyngeal: Roof posteriorly.

3 The two terminal branches of the third part of the maxillary artery are the posterior nasal artery and the sphenopalatine artery (Nomina Anatomica, 1966). Others have used the term sphenopalatine to refer to the last centimeter of the maxillary artery, and described this as bifurcating into the lateral nasal and septal branches. (The septal branch also has been called the nasopalatine artery.)

Superior labial artery (from facial artery): Tip of the septum and ala nasi. Its anastomosis with a branch of sphenopalatine forms Kiesselbach's plexus in Little's area.

6. Venous drainage opens into:

a. Sphenopalatine and anterior facial veins. b. Ophthalmic veins. c. Veins of the orbital surface of the frontal lobe of the brain (via foramina in the cribriform plate). d. Superior sagittal sinus (via foramen caecum).

7. Innervation:

a. Anterior ethmoid: From ophthalmic division of trigeminal.

1) Medial.

2) Lateral.

b. Branches of the sphenopalatine ganglion:

1) Lateral posterior superior (short sphenopalatine).

2) Medial posterior superior (septal). Nasopalatine (long sphenopalatine).

3) Greater palatine.

c. Olfactory nerves: Roof, upper third of nasal mucous membrane.

8. Lymphatic drainage: Anterior part of cavity to submandibular nodes. Posterior part of cavity to upper deep cervical glands.

9. Mucous membrane:

a. Pseudostratified ciliated columnar epithelium, except in:

1) Vestibule and nares: Stratified squamous.

2) Olfactory areas: Nonciliated pseudostratified columnar epithelium with serous glands of Bowman and bipolar olfactory cells.

4 Nasal Physiology

The nose participates in three major functions: (1) respiration, (2) olfaction, and (3) phonation.

A. Respiration

1. Acts as rigid airway for inspiration and expiration of air.

2. Heat exchange: Inspired air is heated to about 36°C, white heat is withdrawn from expired air.

3. Humidification: Inspired air is humidified to 75-80%, while water is withdrawn from expired air to reduce the amount of insensible loss.

4. Filtration: The nose removes most particles 4.5 microm in size from inspired air, some as small as 1 nanom.

5. Mucociliary transport depends on ciliary activity and production of nasal secretions; over 1000 cc of secretions produced per day; acts to clear contaminants of inspired air from nose. Mucus contains muramidase, which breaks down bacterial cell walls, as well as IgA and IgE immunoglobulins.

6. Nasopulmonary reflex: Via hypothalamus, influences both nasal airway resistance and pulmonary compliance.

B. Olfaction: Odoriferous particles must be in solution. They stimulate bipolar neurons which converge to form the olfactory nerve, which leaves the nose via the cribriform plate.

C. Phonation: Adds resonance to the voice.

Nasal Pathology - External Nose

A. Furunculosis

1. Superficial abscess, occurring most frequently around the nasal vestibule in the region of hair follicles, causing erythema, swelling, and marked pain.

2. Staphylococcus aureus usual infecting agent.

3. Untreated, can cause serious complications, i.e. cavernous sinus thrombosis.

4. Treatment with penicillinase resistant antibiotics, heat, incision and drainage (I and D) if pointing.

5 B. Impetigo

1. Superficial skin infection presenting with a vesicopustule formation which forms yellow crusts.

2. Caused by both hemolytic staphylococci and group A hemolytic streptococci.

3. Treatment with appropriate antibiotic.

C. Erysipelas

1. Acute streptococcal infection of the skin.

2. Initial symptoms include feverishness, headache, and malaise.

3. Lesion has advancing border which is raised from surrounding skin. Skin is tense and dark dull red, hot, and tender.

4. Treated with systemic penicillin.

D. Lupus vulgaris

1. Form of tuberculosis involving external nose and adjacent facial areas.

2. Produces brownish, gelatinous nodules which may coalesce.

3. Therapy is identical to that for tuberculosis of other anatomic areas.

E. Lupus erythematosus

1. Disease of unknown cause, featuring altered immune reactivity, which can effect any organ system.

2. Pleomorphic, erythematous, maculopapular eruptions occur commonly on face, sometimes presenting as a "butterfly" rash.

3. Diagnosis is difficult and no curative treatment is known.

F. Syphilis

1. Veneral spirochetosis caused by the organism Treponema pallidum.

2. Primary syphilis of the nose is rare, usually occurring 3-4 weeks after contact as indurated, painless ulceration at the mucocutaneous junction or adjacent septum, accompanied by disproportionate adenopathy.

3. Widespread secondary lesions occur as the primary lesion is disappearing. They appear as erythematous papulosquamous eruptions, annular lesions, mucous patches, and

6 condyloma. The disease resembles an acute rhinitis in the nose accompanied by vestibular fissures.

4. Tertiary syphilis, developing in one-third of untreated patients, presents as nasal gumma, smooth circumscribed swellings covered by inflamed mucosa, with a predilection for the septum. Septal perforations causing "saddle deformity" may occur.

5. Penicillin is the drug of choice.

G. Senile Keratosis

1. Precancerous skin lesion frequently caused by sun exposure.

2. Raised, yellow brown to black pigmented lesion covered with crusts, overlying smooth, vascular surface.

3. Treatment is removal or destruction.

H. Rhinophyma

1. Disease of the skin of the nose characterized by chronic inflammation and hypertrophy of the skin, producing a large, red, violaceous nasal tip and comedones.

2. Typically affects Caucasian males between ages 40 and 60 years and involves the lower one-half of the nose.

3. Histology shows sebaceous gland hypertrophy, scarring, acanthosis, and frequently telangiectasia. These features also are seen in acne rosacea. Excessive intake of alcohol is not a direct cause.

4. Treatment is strictly surgical, via full thickness excirion or decortication. Skin grafting is rarely necessary.

I. Dermatofibrosarcoma Protuberans

1. Involves the dermal layer of skin, presenting as a multinodular, firm, painless mass. Has potential of local growth and rare metastases.

2. Composed of small, uniform, fibrocystic-appearing cells arranged in a cartwheel pattern.

3. Treatment is wide excision.

J. Relapsing Polychondritis

1. Rare connective tissue disorder characterized by episodic recurring inflammation of cartilaginous structures.

7 2. Cartilage of ear, joints, and nose most commonly affected, producing pain and swelling. May produce saddle nose.

3. Nonspecific laboratory findings of anemia and elevated ESR.

4. Diagnosis based on history and biopsy.

5. Treatment is symptomatic, with anti-inflammatory agents (salicylates and corticosteroids) and occasionally cytotoxic drugs.

Nasal Pathology - Traumatic

A. Nasal Fractures

1. Most commonly fractures bone in body.

2. Symptoms include nasal deformity, swelling, pain, tenderness, mobility of nasal bones, and nasal obstruction.

3. Treatment includes repair of nasal lacerations, examination for septal hematomas with drainage if found, and elevation of nasal bones under satisfactory local anesthesia. Intranasal packing usually is not necessary. External protection with splint.

B. Septal Deciation

1. Deviations and dislocations of the septum may be classified in two groups: traumatic and developmental.

2. Septal deformities after trauma are separated in three groups.

a. Lateral type: Results from lateral fracture of the nose with displacement of the septum from the vomerian groove and maxillary crest.

b. Depressed type: Following a crushing frontal fracture and resulting in bizarre septal configurations of buckling, twisting, reduplication, and fibrosis.

c. Laterofrontal type: Combines the above two.

3. In the developmental type of septal deformity, the cartilaginous septum is dislocated and deflected and there is similar deviation of the underlying bony septum.

4. Major symptom is airway obstruction and may contribute to rhinitis.

5. Correction is surgical.

6. Correction of deviated septum is frequently necessary to correct external nasal deformities.

8 C. Septal Hematoma

1. Collection of blood beneath the mucoperichondrium and mucoperiosteum of the septum.

2. Cause is usually traumatic.

3. Symptoms include nasal obstruction. Palpation will reveal fluctuation of septum.

4. If untreated, may result in septal abscess, cartilaginous necrosis, and saddle nose.

5. Treatment includes incision and drainage, nasal packing to prevent reaccumulation, and antibiotics if infected.

D. Septal perforation

1. Caused by trauma both iatrogenic (septal surgery) and self-induced (nasal picking), septal abscess, granulomatous disease, i.e. Wegener's granulomatosis, and drug induced, i.e. cocaine.

2. Symptoms include crusting, epistaxis, discharge, and whistling on inspiration.

3. Treatment includes local measures (saline douches, application of ointments to perforation edges to diminish crusting), surgical closure (frequently fails), and insertion of septal buttons.

E. Foreign Bodies

1. Usually introduced voluntarily by patient, most often in children.

2. Symptoms include unilateral nasal obstruction and persistent unilateral purulent discharge.

3. Rhinoliths or nasal concretions usually have a foreign body nucleus. They may be bacteria, blood, crusts, or self-introduced foreign body, and are composed largely of calcium and magnesium salts. They have rarely been reported bilaterally.

4. Treatment of foreign bodies and rhinoliths is removal. This may require general anesthesia.

F. CSF Rhinorrhea

1. Flow of cerebrospinal fluid from the nose. May originate from the cribriform plate, frontal, sphenoid, or ethmoid sinuses, or middle ear via the eustachian tube.

2. Trauma is the most common cause, i.e. motor vehicle accidents. Can occur postoperatively (i.e. hypophysectomies), secondary to tumors (i.e. chromophobe adenoma), or may be idiopathic.

9 3. Diagnosis is based on history (clear, watery discharge, intermittent or constant, which increases with change in head position) as well as radiologic methods (polytomography). Localization of leaks is accomplished by intrathecal injections of various stains (usually fluorescein) followed by examination of appropriately placed cotton pledgets (middle meatus, cribriform plate, sphenoethmoid recess).

4. Test for glucose in secretions is unreliable, since substantial amounts of glucose can occur both in nasal discharge and tears.

5. Treatment may be conservative initially; prophylactic antibiotics are probably of little value. Surgical approach to closure usually is via external ethmoidectomy. Various flaps or muscle and fascia plugs are used for closure.

G. Epistaxis

1. Etiology

a. Local disorders including traumas, crusting and ulceration, infection, and foreign body reactions.

b. Neoplastic disorders including malignant neoplasms, and juvenile nasopharyngeal audiofibromas.

c. Systemic disorders: Hypertension.

d. Hematologic disorders: Leukemia, anemia, purpura, polycythemia vera, hemophilia and other coagulopathies, lymphoma, anticoagulation (including ASA).

e. Other disorders: Osler-Wever-Rendu disease (familial hemorrhagic telangiectasia), hepatic disease, chronic nephritis, sudden pressure changes.

f. Ninety percent of epistaxis comes from Kiesselbach's plexus on the nasal septum. Posterior inferior bleeding usually comes from the sphenopalatine vessels. Superior bleeding usually comes from the anterior and posterior ethmoidal arteries.

2. Medical management

a. Locate bleeding site.

b. Remove clots from nose.

c. Shrinkage (decongestants, cocaine).

d. Adequate anesthesia important: cocaine, lidocaine (Xylocaine), tetracaine (Pontocaine).

e. Pressure while medications are working.

10 f. Cautery: Either chemical (silver nitrate) or electrical.

g. Carefully placed petroleum gauze pack will stop most bleeding. May need to place bilaterally for adequate measure.

h. Severe posterior bleeding may require posterior pack, either conventional or Foley- type. (Beware of pressure necrosis to the nasal vestibule.)

i. Begin prophylactic antibiotics when due to blockage of sinus ostia.

j. Posterior packs may produce hypoxia. Check blood gases, and provide supplemental

O2 as indicated.

k. Beware of excessive sedation.

l. Transfuse as necessary.

m. Workup and treat causes of bleeding (include sinus x-rays).

3. Surgical management

a. For uncontrolled or recurrent epistaxis.

b. Ligation of anterior and posterior ethmoidal arteries. For superior epistaxis, this is done through an external ethmoidectomy approach.

c. Ligation of branches of the internal maxillary artery. Through a Caldwell-Luc approach the posterior antral wall is exposed. This is removed under microscopic visualization to expose the pterygomaxillary fossa. Self-locking neurosurgical clips are placed on the branches of the internal maxillary artery as close to their entrance to the nose as possible.

d. Ligation of the external carotid artery: Easy to approach, but less successful because of its distal relationship to the actual bleeding vessels.

e. If vessel ligation fails to control epistaxis, angiography with Gelfoam embolization of the offending vessel may be of some aid.

f. Septal dermaplasty should be considered in patients with recurrent epistaxis from familial hemorrhagic telangiectasia.

g. Injection of the pterygomaxillary fossa via the greater palatine foramen may temporarily control posterior epistaxis.

11 Pathology - Congenital

A. Cysts: See Benign Tumors Nose and Sinuses. B. Glioma: See Benign Tumors Nose and Sinuses. C. Encephalocele: See Benign Tumors Nose and Sinuses. D. Teratomas: See Benign Tumors Nose and Sinuses. E. Choanal Atresia

1. A result of persistence of the nasobuccal membrane.

2. Eighty to ninety percent are bony or membrano-osseous, the remainder being membranous. Familial tendency.

3. One-third are bilateral, two-thirds are unilateral.

4. When bilateral the condition causes airway obstruction in neonates, who are obligate nasal breathers for up to several weeks. The apneic state is broken if the infant cries. It can cause death if not recognized.

5. Unilateral atresia causes peristent nasal drainage and excoriation of the nasal vestibule.

6. Diagnosis is made by passing a flexible catheter through the anterior nares. It should pass more than 32 mm.

7. Bilateral atresia is treated initially with McGovern's nipple.

8. Surgical correction is accomplished by a transnasal, transseptal, or transpalatal approach.

Pathology - Rhinitis

Rhinitis is hyperfunction of the nose due to various stimuli, producing rhinorrhea and nasal obstruction. Classification as to etiology difficult.

A. Vasomotor Rhinitis

1. Nonspecific diagnosis of unexplained hypersensitivity rhinitis.

2. Increase in acetylcholine in nasal mucosa (possibly due to deficient acetylcholinesterase) characterized by increased parasympathetic tone.

3. Nasal smear may show mastocytosis, with sparsity of eosinophils.

4. Allergic workup negative.

5. Treatment.

12 a. Medical: Steroids, topical, submucosal, or systemic.

b. Surgical: Directed to inferior turbinate or vidian nerve.

B. Allergic Rhinitis

1. IgE-mediated response causing release of vasoactive substances from mast cells.

2. Nasal smear shows eosinophilia.

3. Other allergic manifestations usually present.

4. Treatment.

a. Avoidance.

b. Medications: Include antihistamines, topical steroids (beclomethasone, flunisolide), decongestants.

c. Desensitization: About 70% effective.

C. Atrophic Rhinitis

1. Etiology unknown. Theories include hereditary, develomental, and endocrine factors, bacterial infections, and nutritional deficiencies. Can be iatrogenic (i.e. excessive turbinate resection).

2. Symptoms include nasal obstruction, epistaxis, anosmia, and offensive odor.

3. Examination reveals excessive crusting and turbinate atrophy.

4. No cure available. Nasal irrigation helpful. Surgical approaches are designed to narrow internal dimensions of nose.

D. Rhinitis Medicamentosa

1. Caused by excessive use of topical nasal decongestants, both sympathetic amines and the imidazoles.

2. Treatment includes avoidance of topical deongestants, along with the use of systemic decongestants and topical steroids.

E. Metabolic Rhinitis

1. Seen with hypothyroidism.

13 F. Hormonal Rhinitis

1. Frequent side effect of pregnancy. Increased estrogen levels inhibit acetylcholinesterase thus increasing parasympathetic tone.

2. Also seen at puberty and with the use of oral contraceptives.

G. Infectious Rhinitis

1. Both viral ("common cold") and bacterial (purulent).

Necrotizing Lesions of the Nose

These lesions are evidence of an underlying systemic disease. Identification of causative organism, appearance of characteristic morphology, and presentation of a careful history will clarify pathogenesis. Final diagnosis rests with biopsy.

A. Vasculitis

1. Wegener's granulomatosis.

a. Necrotizing granulomas with vasculitis involving the respiratory tract and kidney (necrotizing glomerulitis).

b. Nasal obstruction, followed by mucosal destruction, crusting, and septal perforation.

c. Systemic symptoms (also night sweats, malaise, arthralgias).

d. Biopsy of nose reveals inflammation and necrosis.

e. Treated with cytotoxic agents and steroids.

2. Systemic lupus erythematosus (see Pathology - External Nose).

a. Ulcerations of nasal mucosa may occur during severe exacerbations of SLE.

3. Scleroderma

a. Chronic disease of unknown cause characterized by diffuse sclerosis of the connective tissue of the integument and other organs.

b. Obliterative vascular lesions may result in ulceration of nasal mucous membranes.

4. Sjögren-Sicca Syndrome

a. Syndrome complex including keratoconjunctivitis, xerostomia, enlargement of the lacrimal and salivary glands, and rheumatoid arthritis.

14 b. Nasal mucosa may be dry, atrophic, and ulcerated.

B. Infectious

1. Tuberculosis.

a. Uncommon in the nasal cavity.

b. Symptoms include discharge, crusting, pain, and nasal obstruction.

c. May involve the anterior septum or inferior turbinate with gross appearance ranging from superficial ulceration to a papillomatous mass. Septal perforations may occur.

d. Diagnosis is made by a positive smear, culture, and biopsy.

e. Treatment is the same as for pulmonary tuberculosis.

2. Syphilis: see Nasal Pathology - External Nose.

3. Leprosy.

a. Chronic granulomatous infection which attacks superficial tissues, especially skin, peripheral nerves, and nasal mucosa.

b. Caused by Mycobacterium leprae (Hansen's bacillus).

c. Nasal symptoms include epistaxis and obstruction.

d. Necrosis of nasal structures results in septal perforation and saddle nose.

4. Glanders.

a. Infection primarily of equine animals which can be transmitted to man, due to Pseudomonas mallei.

b. Produces extensive ulcerating granulomatous lesions of the nasal mucosa causing mucopurulent discharge.

5. Rhinoscleroma.

a. A granulomatous disease caused by Klebsiella rhinoscleromatis.

b. Foul-smelling rhinorrhea followed by atrophy and crusting, and finally granulomatous nodules causing fibrosis and stenosis.

c. Culture from infected tissue is diagnostic.

d. "Mickulicz cell" (foamy histiocyte) characteristic.

15 e. Tetracycline is the drug of choice in treating disease.

6. Rhinosporidosis.

a. Caused by Rhinosporidium seeberi, a funguslike organism.

b. Presents with exophytic, branching, granular, deep red, pedunculated or sessile polypoid growths in the nose.

c. Symptoms include nasal obstruction and epistaxis.

d. Treatment is by surgical removal or lesions followed by dapsone.

7. Mucormycosis: see Fungal Sinusitis.

8. Aspergillosis: see Fungal Sinusitis.

9. Candidiasis: see Fungal Sinusitis.

10. Actinomycosis.

a. Caused by Actinomyces israelli, and A. bovis, a bacterial form.

b. Can cause a purulent abscess of the nose and antrum.

c. Distinguishing feature is the presence of sulfur granules.

d. Treatment is with penicillin.

11. Histoplasmosis.

a. A granulomatous fungal disease caused by Histoplasma capsulatum.

b. Usually involves lungs, larynx, and tongue.

c. Nodules and ulcers composed of masses of organisms are found.

d. Epithelioid or histiocytic granuloma is seen with organisms within the granuloma.

e. Treatment is with amphotericin B.

12. Cryptococcosis.

a. Caused by the fungus Cryptococcus neoformans.

b. Usually affects the pulmonary system, central nervous system, or general body, but may be localized to the nose or sinuses.

16 c. Produces granulomatous lesions typically lacking a prominent inflammatory reaction.

d. Treatment is with amphotericin B.

13. Blastomycosis.

a. Chronic granulomatous and suppurative disease, involving the respiratory tract and spreads to other sites, including the face, external nose, and nasal cavity.

b. Caused by Blastomyces dermatitidis.

c. Produces ulcerated or verrucous granuloma of the nasal mucosa with a serpiginous advancing, elevated border.

d. Treatment is with amphotericin B.

C. Neoplastic Disease

1. Histiocytosis.

a. Includes three separate entities: (1) Eosinophilic granuloma, (2) Hand-Schüller- Christian disease, and (3) Letterer-Siwe disease.

b. Development of infiltration of differentiated histiocytes, accompanied by a variable mixture of eosinophils, giant cells, neutrophils, foamy cells, and areas of fibrosis.

c. Etiology of disease is unknown.

d. May present with nasal mass - diagnosis by biopsy.

e. Treatment includes surgery, radiotherapy, steroids, and cytotoxic therapy.

2. Lymphoma.

a. Lymhocytic lymphoma most frequently is encountered in the sinonasal tract.

b. Symptoms suggest an inflammatory disease which initiates a more disfiguring and destructive phase.

c. Diagnosis is based on biopsy.

d. Treatment is with radiotherapy and chemotherapy.

3. Mycosis fungoides.

a. Uncommon neoplastic disease of the lymphoreticular system first manifested in the skin.

17 b. May cause shallow ulcerations of the nasal mucosa, although tumors may develop.

c. Diagnosis is made on biopsy.

D. Treated with topical and systemic chemotherapy, topical and local steroids, and radiation.

4. Lymphoepithelioma.

a. More frequently found in the nasopharynx.

b. Diagnosis is by biopsy.

c. Highly radiosensitive.

5. Malignant melanoma.

a. Poorest prognosis of all primary neoplasms of the sinonasal tract.

b. Patients complain of nasal obstruction, epistaxis, and occasionally black discharge.

c. Pigmented necrotic hemorrhagic mass causing obvious destruction is seen within the nose.

d. Surgery remains the most effective treatment.

D. Unknown Etiology

1. Sarcoidosis.

a. Systemic disease, usually with abnormal chest roentgenograms.

b. May involve the external nose (papular lesion), septum, or turbinates with classic granulomas. Patient may complain of nasal obstruction, plus clear watery rhinorrhea.

c. Biopsy reveals noncaseating epithelioid granulomas in the lymphoreticular tissue.

d. May require systemic steroids and surgery.

2. Necrotizing sialometaplasia.

a. Benign lesion that represents nonspecific reaction of salivary and mucous glands to ischemic injury.

b. May produce a deep excavating crater in the nose, causing severe epistaxis.

c. Treatment is with surgical excision.

18 3. Pyogenic granuloma.

a. Localized, specific, often ulcerated polypoid lesion composed of newly formed capillaries in an edematous matrix.

b. Present as bright red to reddish brown vascular tumors which tend to form crusts and undergo necrosis.

c. May spontaneously involute, or may need excision.

4. Idiopathic midline granuloma.

a. Destructive localized or diffuse lesions, with characteristic extension through the palate and facial soft tissues.

b. Localized to airway and upper aerodigestive tract.

c. May remain histologically benign or evolve into polymorphic reticulosis.

d. Inflammatory reaction is nonspecific. Granulomas and giant cells are infrequent.

e. Impairment of delayed hypersensitivity often is seen.

f. Treatment is irradiation.

5. Polymorphic reticulosis.

a. Unlike idiopathic midline granuloma, systemic complaints are often out of proportion to nasal symptoms.

b. Destruction of facial soft tissues similar to idiopathic midline granulomas.

c. No vasculitis or glomerulonephritis. May not have airway lesions.

d. May involve into lymphoma (extranodal or disseminated).

e. Characteristic atypical and polymorphic lymphoreticular cellular infiltrate, angiocentric growth patterns. May simulate vasculitis, but fibrinoid necrosis absent in vessel walls.

f. Treatment is radiation.

19 Disturbance in Olfaction

A. Hyperosmia

1. Oversensitive sense of smell.

2. Occurs with hunger, cystic fibrosis, and Addison's disease.

B. Parosmia

1. Perverted sense of smell.

2. May occur with injury to uncus of temporal lobe.

3. Occurs secondary to some drugs (i.e. streptomycin).

4. May occur in postinfluenzal patients.

5. Must be differentiated from olfactory hallucinations as seen in schizophrenia, and from uncinate seizures secondary to lesions of the uncinate gyrus, amygdaloid nucleus, or hippocampus.

C. Hyposmia

1. Impaired sense of smell.

2. Seen with increasing age, postmenopausal women, and in tobacco smokers.

D. Anosmia: Loss of sense of smell.

1. Intranasal conditions that block the flow of air to the olfactory mucosa.

a. Seen in rhinitises, sinusitis, polyps, intranasal or nasopharyngeal tumors, choanal atresia, and vitamin A deficiency.

2. Trauma

a. Contrecoup frontal damage from occipital head injury.

b. Fracture of the cribriform plate (LeFort's II or III, frontoethmoidal fractures).

c. Injury to olfactory nerves or bulb.

d. One-third of patients with traumatic anosmia.

3. Infection.

a. Usually postinfluenza.

20 b. Vitamin A has been advocated as treatment, though proof of efficacy is lacking.

4. Tumor.

a. Sphenoidal ridge meningiomas produce ipsilateral anosmia, unilateral optic atrophy or papilledema, and exophthalmos.

b. Olfactory groove or cribriform plate meningiomas present with unilateral anosmia, retrobulbar neuritis, or optic atrophy.

c. Frontal lobe gliomas present with unilateral anosmia and optic atrophy.

d. Foster-Kennedy syndrome, produced by frontal lobe tumors, consists of ipsilateral anosmia, and optic atrophy, with contralateral papilledema.

e. Parasellar or pituitary tumors may present with bilateral anosmia.

5. Congenital.

a. May be complete, or selective.

b. May occur sporadically, or may be either autosomal or sex-linked.

c. Complete anosmia is seen in familial dysautonomia and chromatin-negative gonadal dysgenesis.

6. Hysteric anosmia

a. Hysteric anosmiacs will deny smelling ammonia which is sensed by the trigeminal nerve, not the olfactory nerve.

Benign Tumors of the Nose and Paranasal Sinuses

A. Nasal Polyp

1. Most common tumor of the nasal cavity. Equal incidence in sexes and socioeconomic groups.

2. Multiple causes exist.

a. Twenty-five percent of an allergic group had polyps.

b. Fifty-four percent of patients with polyps had allergies.

c. Also seen with infection, trauma, metabolic disease, cystic fibrosis, aspirin intolerance, asthma.

3. Nasal obstruction, rhinorrhea, and anosmia are usual symptoms.

21 4. Translucent, pear-shaped polyps (single or multiple) seen unilaterally or bilaterally. Unilateral "polyps" may represent choanal polyp, encephalocele, inverted papilloma, angiofibroma, carcinoma, or sarcoma.

5. Increased eosinophilia commonly are seen on nasal smear.

6. Medical therapy includes diet, desensitization, decongestants, antihistamines, antibiotics (when indicated), and steroids.

7. Surgical therapy includes polypectomy, with or without ethmoidectomy, and Caldwell-Luc operation if indicated.

B. Inverted Papilloma

1. Usually unilateral, male preponderance.

2. May resemble nasal polyps but far less translucent.

3. Thickened surface epithelium with invagination into supporting stroma.

4. About 10% develop squamous cell carcinoma.

5. Major symptoms include nasal obstruction, sensation of mass in nose, epistaxis, and rhinorrhea.

6. Complete excision is important because of frequent recurrence.

a. Calcaterra suggests lateral rhinotomy, medial maxillectomy, and ethmoidectomy.

C. Squamous Papilloma

1. Similar to squamous papilloma of other areas of the skin (commonly called a wart).

2. Usually found in the area of the ala or nasal vestibule.

3. If further posterior in nasal passage may be more mucoid, softer, and vascular.

4. May involve the sinuses.

5. May cause nasal obstruction or hemorrhage.

6. Usually require surgical excision.

D. Nasal Glioma

1. Herniation of brain tissue through the floor of the anterior cranial fossa. If it communicates with ventricular system it is an encephalocele.

22 2. Clinically, smooth mass which may be polypoid and swell with crying.

3. Beware of removal without neurosurgical evaluation and therapy.

E. Neural Tumors

1. Uncommon in nose.

2. Neurofibroma and neurilemoma are most often seen.

F. Hemangioma

1. Capillary hemangioma: Loosely arranged tissue containing thin-walled blood vessels.

a. Occurs most frequently on the nasal septum.

b. Treated by excision and electrocautery.

2. Cavernous hemangioma: Thin-walled growth with afferent and efferent vessels.

a. Usually seen in lateral wall of the nose.

b. Infiltrates, destroys tissue and can cause severe hemorrhage.

c. May require surgery, cauterization, freezing, and occasionally requires ligation of the external carotid artery.

G. Osteoma

1. Most commonly found at frontoethmoid suture.

2. May occur in frontal, ethmoid, or maxillary sinuses, or from nasal septum or turbinate.

3. Slow growing and produce symptoms (usually headache in frontal sinus) when large.

4. May extend into orbit or cranial cavity.

5. Diagnosed radiographically.

6. Surgical removalis symptomatic or expanding.

23 H. Cysts

1. Radicular cyst, seen in maxilla, develops from apical abscess of an erupted tooth.

2. Globulomaxillary cyst results from entrapment of epithelim at the junction of the premaxilla and maxillary process. May distort teeth.

3. Nasoalveolar cyst: A developmental cyst located in the soft tissue at the junction of the premaxilla and alveolar process.

4. Rathke's pouch tumor: Cyst lined with squamous cells, filled with kerating, and located in the nasopharynx.

a. Due to failure of Rathke's pouch to obliterate.

b. Pouch formed by invagination of oral ectoderm in formation of anterior of the pituitary gland.

I. Dermoid cyst: Usually present at birth and seen at suture line between nasal bones and nasal process frontal bones.

1. May extend into nasal cavity, frontal, ethmoid, or maxillary sinuses, or intracranially.

J. Thornwald's cyst: Derived from pharyngeal notochord remnant and found in the nasopharynx, in the midline superior to adenoidal pad.

1. Can become infected and cause drainage and discomfort.

2. Requires surgical excision or marsupialization.

K. Chordoma: Arises from remnant of notochord in nasopharynx.

1. Causes nasal obstruction or cranial nerve involvement.

2. Histologically benign but cervical metastases have been reported.

3. Surgical excision is therapy but complete excision is difficult.

L. Plasmacytoma (extramedullary): May be isolated or part of multiple myeloma.

1. Most found in nose, nasopharynx, and sinuses.

2. Therapy and prognosis uncertain.

M. Teratoma: Derived from all germ layers and often associated with other cranial abnormalities. Seen in midline.

24 N. Fibrous Dysplasia

1. Mixture of fibrous tissue and cancellous bone seen in maxilla.

2. Slow growing tumor causes cosmetic defect.

3. Requires surgical excision and may undergo malignant degeneration.

Anatomy of the Paranasal Sinuses

a. Maxillary Sinuses (Antrum of Highmore)

1. The largest of the paranasal sinuses is located in the body of the maxilla and has a volume of 15 mL.

2. It is pyramidal cavity with its apex extending laterally and its base directly toward the nasal cavity.

3. The floor of the antrum, formed by the alveolar process of the maxilla, is usually 3-5 mm below the level of the floor of the nasal cavity, except in children where the floor is at or above the level of the floor of the nasal cavity.

4. The thin medial wall is the lateral wall of the nasal cavity. It is through this wall that the sinus drains into the nose, into the middle meatus behind a projection made by the uncinate process of the ethmoid. Often an accessory opening is seen posterior to the primary opening (30-40%). These openings are above the floor of the sinus and require active transportation of mucus and purulent matter to empty the sinus. Improved drainage is gained by creating a "nasoantral window" (nasal antrostomy) from the inferior meatus to the lower portion of the sinus.

5. The roof is formed by the orbital surface of the maxilla and also serves as the floor of the orbit. The infraorbital nerve is contained in a ridge located in the center of the roof.

6. The cheek overlies its anterior wall. The surgical approach to the sinus is through the canine fossa over the bicuspid and molars and through the anterior sinus wall. (Caldwell- Luc operation)

7. The posterior wall overlies the pterygoid space. Opening this wall allows access to the internal maxillary artery and the vidian nerve as well as tumors which might spread from the nasopharynx to this area (juvenile angiofibroma, rhabdomyosarcoma).

8. The sinus is best appreciated roentgenologically in a Waters' view. Serial Waters' views can be used to follow the progress of acute sinusitis. Polytomography and computerized axial tomography (CAT scan) better define spread in lesions and bony destruction.

25 B. Ethmoid Sinuses

1. Located between the middle turbinate and the medial orbital wall, the thin walled ethmoid sinuses number 7-15 per side and have a volume of 14 mL.

a. The anterior ethmoid sinuses (usually small and numerous) are found below the attachment of the middle turbinate, drain into the middle meatus, and form the bulla ethmoidalis in the nose.

b. The posterior ethmoid sinuses (larger and fewer) are superior and posterior to the attachment of the middle turbinate, and drain into the superior meatus.

c. The ethmoid cells may invade any of the surrounding bones, including frontal, sphenoid, and maxillary bones. The anterior cells extend into the agger nasi and uncinate process.

2. The middle turbinate is an osseous shelf approximately 3.5-4 cm in length and is sometimes pneumatized with an ethmoidal cell (4-12%). Its anterior attachment is to the cribriform plate. This plate measures only 2 cm long by 5 mm wide and is 2 mm thick. These small dimensions leave little room for error while performing intranasal surgery. Any instrumentation medial to the attachment of the medial turbinate should be done with extreme caution.

3. The lateral wall of the ethmoid sinuses (the medial wall of the orbit) is known as the lamina papyracea (paper-thin plate). Indeed, so thin is the bone that occasionally natural dehiscences occur in its surfaces, permitting the development of orbital cellulitis from an ethmoiditis.

a. Where the lamina papyracea articulates with the frontal bone lie the anterior and posterior ethmoidal foramina, each containing an artery and neural twig. These arteries supply blood to the superior aspect of the nose and occasionally are ligated for severe epistaxis. The optic nerve lies 3-8 mm deeper than the posterior artery.

b. The anterior and posterior foramina form a line parallel to, and just inferior to, the anterior cranial fossa (cribriform plate) and serves as a valuable landmark.

4. The posterior ethmoid cells are never far from the optic nerve, the closeness being dependent on the pneumatization of the sphenoid bone. The sphenoid sinus may surround the nerve or if the sinus does not pneumatize, the posterior ethmoidal cells may invade the bone and come into intimate relationship in the nerve. This relationship makes external ethmoid surgery safer than intranasal or transantral ethmoid surgery especially where there is poor access to the sinus.

5. The ethmoid sinuses are best seen on Caldwell's (AP) and lateral roentgenograms. CAT scans have greatly improved our ability to evaluate these sinuses.

26 C. Frontal Sinuses

1. The frontal sinuses are located in the frontal bone above and deep to the superior orbital ridge. The two sinuses, usually unequal in size, form an irregular pyramid with the apex directed upward. The volume is usually 6-7 mL. About 15% of adult skulls have only one sinus and 5% have none.

2. The sinuses are separated by a thin septum of bone which is not always present and only occasionally in the midline. The depth of the two sinuses often vary causing confusion on AP roentgenograms. Lateral films are necessary for full appreciation of frontal sinus opacification.

3. The sinus drains into the nose through the nasofrontal duct located on the anteromedial aspect of the sinus floor. It runs through the ethmoidal labyrinth and enters the ethmoidal groove at the anterior end of the middle meatus. Drainage also may occur into the frontal recess anterior to the infundibulum (55%), above the infundibulum (30%), into the infundibulum (15%), and above the bulla (1%).

4. For acute infections not responding to medical therapy a frontal trephination through the floor of the sinus might be necessary. A drain for irrigation usually is left in place.

5. Chronic frontal sinusitis usually is treated by an osteoplastic flap procedure with fat obliteration of the sinus cavity. This gives good exposure of the sinus and is not deforming, as were many of the earlier procedures.

D. Sphenoid Sinuses

1. The sphenoidal sinus are located in the sphenoid bone behind the upper part of the nasal cavity. They vary greatly in size and shape probably because they represent an ingrowth from the nose. The usual volume is 7.5 mL.

a. They are commonly very deep in their anteroposterior dimension.

b. Laterally they may invade the greater and lesser wings, pterygoid process, and lateral pterygoid plates of the sphenoid.

c. The sinuses usually are separated by a septum which usually deviates to one side but is occasionally absent.

2. The openings of the sinuses are medial and superior in the rostrum of the sphenoid and the sinuses drain into the superior meatus through the sphenoethmoid recess.

3. The cavernous sinus and optic nerve are located laterally to the sphenoid sinuses. The carotid artery and vidian nerves commonly cause a ridge on the lateral wall if the sinus pneumatically expands laterally for any distance.

4. The pituitary gland is located posteriorly and superiorly and commonly bulges into the superior wall. This relationship enables one to perform a transsphenoid hypophysectomy.

27 5. Respect to the lateral and superior walls must be shown. The inferior wall is the safest.

6. Three types of pneumatization are recognized:

a. Postsphenoid pneumatization (about 60%): Pneumatization extends posteriorly below the pituitary fossa so that the sella turcica projects its anterior wall into the sinus.

b. Presphenoid pneumatization (about 40%): The sinus is pneumatized as far as the anterior bony wall of the pituitary fossa.

c. Conchal pneumatization (about 1%): The sinus is rudimentary, having little depth. A contraindication to transsphenoid hypophysectomy.

7. The type of pneumatization is well shown on the lateral roentgenographic view of the sinuses. The sinus also is seen on the basal view.

Diseases of the Sinus

A. Acute Sinusitis

1. Etiology: Usually follows an upper respiratory infection, but may follow trauma, excessive drying, edema (allergic), or nasal obstruction. Gram-positive organisms (usually pneumococci, Haemophilus influenzae, group A beta streptococci, or Staphylococcus aureus.)

2. Symptoms: Heaviness in the sinus, pain, nasal obstruction, and blowing of a malodorous yellow or green mucopurulent discharge.

3. Findings: Pus in the nose, edema and redness of nasal mucosa, tender over sinuses, opaque sinus, sometimes with an air-fluid level.

4. Therapy: Antibiotics (usually ampicillin/amoxicillin), nose drops, (oral decongestants), and analgesics. Occasionally need to drain frontal sinus if therapy does not work.

B. Chronic Sinusitis

1. Etiology: May follow poorly treated acute sinusitis, may be associated with allergy.

2. Symptoms: Chronic purulent discharge and nasal obstruction may be the only symptoms. Pain and pressure on occasion.

3. Findings: This purulent discharge and nasal obstruction. Occasional polypoid changes.

28 4. Therapy: May respond to antibiotics, but also may require surgical intervention:

a. Maxillary sinus: Repeated antral lavage with saline might cure. Otherwise, Caldwell- Luc and nasal antrostomy.

b. Ethmoid sinus: External ethmoidectomy is the safest approach. Intranasal ethmoid surgery usually reserved for polyps.

c. Frontal sinus: Osteoplastic flap procedure with obliteration of the sinus cavity with abdominal fat is the operation of choice. Cannulization of the nasofrontal duct should be avoided.

C. Fungal Sinusitis (rare)

1. Mucormycosis (rhinocerebral phycomycosis): A severe acute illness in debilitated persons (50% with untreated diabetes; also imunosuppressive agents and prolonged corticosteroid usage). Spreads rapidly to involve the eye and central nervous system. Black crusting in the nose, with perforated septum, cranial nerves III, IV, VI involvement and loss of vision. X-ray: Nodular thickening of soft tissues lining sinuses. Hyphae seen on biopsy; high mortality. Therapy is prolonged use of amphotericin B.

2. Aspergillosis: May follow other infection or prolonged antibiotics. Similar signs and symptoms of chronic sinusitis. May require Caldwell-Luc. Excellent prognosis.

3. Candidiasis: Similar to above. Use nystatin irrigation.

Complications of Sinus Disease

A. Orbital Pain

1. Common in acute infections of all sinuses.

a. Pain from sphenoid is usually retro-orbital.

2. Less common with chronic infections or tumors, but when disease spreads to orbit, pain is increased.

B. Lid Swelling

1. Seen with acute maxillary, frontal, and ethmoid sinusitis.

2. Location of sinus determines which lid is swollen.

29 C. Exophthalmos

1. Not usually of sinus origin.

2. Present if sinus infections spread into the orbital spaces or by extension of tumor from sinus into orbit.

D. Orbital Cellulitis

1. Etiology: Usually from ethmoid sinusitis, but may come from any of the sinuses.

2. Symptoms:

a. Lid edema, followed by exophthalmos, chemosis, and progressive immobility of eye.

b. Patient is usually very ill with a high fever and severe pain in the eye.

c. Roentgenograms identify the origin of infection.

3. Therapy:

a. Vigorous intravenous antibiotic therapy.

b. Exploration of orbit with I and D and usually external ethmoidectomy.

c. Drain abscess for at least 4 days.

E. Mass in the Orbit

1. Location of mass identifies sinus of origin.

a. Supraorbital: Frontal sinus.

b. Medial: Ethmoid sinus.

c. Infraorbital: Maxillary sinus.

2. Most common lesions producing masses are carcinomas, mucocele, and osteomas.

F. Retrobulbar Neuritis

1. Etiology.

a. Fifteen percent of the cases ar caused by sinus disease by direct extension or phlebitis.

b. Similar symptoms also can be from tumors of the sinuses and pituitary.

30 2. Symptoms: Loss of vision, sudden or gradual.

3. Therapy: Antibiotics and sinus surgery.

G. Superior Orbital Fissure Syndrome

1. Etiology: Acute or chronic infection, cyst, or neoplasm extending through the lateral wall of sphenoid sinus.

2. Symptoms: Involvement of contents of superior orbital fissure:

a. First cranial nerve VI, followed by III, IV, and V (with pain in the eye).

b. Later exophthalmos and ophthalmoplegia.

3. Diagnosis: Polytomography and CT scans important in establishing diagnosis.

4. Therapy: Immediate exploration of the sphenoid.

H. Cavernous Sinus Thrombosis (see intracranial complications).

Osteomyelitis

A. Frontal Bone

1. Etiology: Most patients under 30.

a. Hematogenous spread in children. Trauma during acute frontal sinusitis in adults.

b. Females more common than males.

c. May follow swimming, acute exacerbation, chronic sinusitis, or frontal sinus surgery.

d. Staphylococcus aureus most common.

2. Symptoms:

a. Acute course: Headache, edema upper eyelids, doughy swelling of skin over frontal sinus (Pott's puffy tumour), pericranial abscess, may spread intracranially.

b. Chronic course (no perforation inner table): Insidious onset, low-grade fever, local pain, doughy swelling forehead, malaise, and chills. May form fistula.

3. Diagnosis: Physical findings plus x-rays which may not show positive changes (necrosis) for 7-10 days after onset of swelling.

31 4. Therapy:

a. Early onset, high-dose intravenous antibiotics (based on culture).

b. Drainage of localized abscess.

c. Trephine for inspection and culture.

d. Local heat, nasal spray.

e. When in doubt as to involvement of the posterior wall or continuous sinusitis, osteoplastic frontal adipose obliteration surgery.

B. Superior Maxilla

1. Etiology:

a. Usually of dental origin.

b. In infants may be from buccal infection.

c. Sinusitis may produce osteitis and fistulous tract with extension to:

1) Facial surface with abscess formation.

2) Palatine and alveolae process with fistula to roof of mouth.

3) Zygomatic process with extension to pterygoid process.

2. Symptoms:

a. Signs and symptoms of sinusitis, plus:

b. Swelling and chemosis cheek.

c. Exophthalmos and limitation of eye movement.

3. Therapy:

a. Specific high-dose antibiotics.

b. Surgical drainage.

c. Heat.

32 C. Sphenoid bone (rare)

1. Etiology:

a. Associated with osteomyelitis at base of skull or infection of the petrous portion of the temporal bone.

b. Hemolytic streptococcus and Staphylococcus aureus.

2. Symptoms:

a. Profuse postnasal drainage and deep seated headache.

b. May spread laterally to cause superior orbital fissure syndrome.

c. Later spread can cause cavernous sinus thrombosis, brain abscess, encephalitis, and intracranial hemorrhage.

3. Diagnosis:

a. Frequently not diagnosed until complications develop.

b. Polytomography and CT scan help.

4. Therapy:

a. Specific high-dose antibiotics.

b. Surgical drainage.

Frontal Sinus Pneumocele

1. A collection of air under pressure in the tissues which air escapes through a defect in the bony wall of the sinus.

2. May follow trauma (fracture, operation), congenital cleft, dehiscence, or necrosis (secondary to syphilis, osteomyelitis, sinusitis).

3. May be internal (posterior to sinus), external (forehead), or pneumosinus dilatans (excessive dilatation of sinus) which is associated with acromegaly, localized osteitis, or fracture in the region of the sinus.

33 Intracranial Complications of Sinus Disease

A. Etiology

1. Pathways for intracranial involvement:

a. Trauma.

b. Through congenital dehiscences.

c. Direct pathway through sinus wall.

d. Along sheath of olfactory nerve.

e. By way of the communicating veins.

f. By means of septic thrombi along diploic veins.

g. By way of ethmoid or angular veins to cavernous sinus.

h. By way of the orbit.

B. Meningitis

1. Most common intracranial complication (70%).

2. Sphenoid sinus most common site of origin (followed by ethmoid, frontal, and maxillary sinus).

3. May follow nasal or sinus surgery.

4. Organisms include hemolytic streptococcus, pneumococcus, and H. influenzae.

5. Therapy includes antibiotics and drainage of infected sinuses when defined.

C. Epidural Abscess

1. Purulent collection between internal surface of the cranium and the dura.

2. Usually from frontal sinus, with usual sinusitis organisms.

3. CT scan helpful in making diagnosis.

4. Similar therapy to that for osteomyelitis.

34 D. Intracranial Mucocele

1. If expansion of a mucous retention cyst from the sphenoid or frontal sinus.

2. If infected it is a pyocele with the same organisms as osteomyelitis.

3. May be seen on polytomograms.

4. Therapy requires surgery on the sinus.

E. Subdural Abscess (Empyema)

1. Purulence between dura and pia mater.

2. Usually from the frontal sinus, secondary to thrombophlebitis.

3. Intensive headaches and rapid change in consciousness.

4. Therapy requires drainage of subdural space and elimination of sinus infection.

F. Cavernous Sinus Thrombosis

1. Cavernous sinus is reached through nonvalved veins from sphenoid and ethmoid sinuses most frequently.

2. Exophthalmos, chemosis, and eyelid edema followed by ocular muscle paralysis as well as systemic signs.

3. Coagulase-positive S. aureus is usual cause.

4. Therapy is with antibiotics and possibly anticoagulants.

G. Brain Abscess

1. High mortality despite antibiotic therapy.

2. Frontal lobe abscess, usually from frontal sinus but occasionally from sphenoid or maxillary.

3. Temporal lobe abscess, usually otogenic in origin but may result from maxillary or sphenoid sinusitis.

4. Staphylococcal and streptococcal infections are the usual cause.

5. Develops slowly with change in temperament.

6. Shown well by CT scan.

35 7. Requires neurosurgical removal.

36 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 15: The Larynx

Embryology of the Larynx (see Chap. 11, pages 306-310)

Anatomy

Anatomy

The larynx consists of a framework of cartilages, held in position by an intrinsic and extrinsic musculature, and lined by mucous membrane which is arranged in characteristic folds.

The larynx is situated in front of the fourth, fifth, and sixth cervical vertebrae. The upper portion of the larynx, which is continuous with the pharynx above, is almost triangular in shape; the lower portion leading into trachea presents a circular appearance.

Laryngeal Cartilages

The laryngeal cartilages form the main framework of the larynx and consist of:

1. Thyroid cartilage (unpaired). 2. Cricoid cartilage (unpaired). 3. Epiglottis (unpaired). 4. Arytenoid cartilage (paired). 5. Corniculate cartilage (paired). 6. Cuneiform cartilage (paired).

Thyroid Cartilage

The thyroid cartilage (hyaline cartilage) is the largest and encloses the larynx anteriorly and laterally, thus shielding it from all but the most forceful blows. This cartilage is composed of two alae which meet anteriorly, dipping down from above to form the thyroid notch before meeting at the protuberance of the Adam's apple. Posteriorly, each wing has a superior cornu, extending upward about 2 cm, and a much shorter inferior cornu which articulates with the cricoid cartilage below. This is the only direct articulation of the thyroid cartilage, all other relationships with contiguous structures being maintained by muscles or ligaments.

Cricoid Cartilage

The cricoid cartilage (hyaline cartilage) lies directly below the thyroid cartilage. It is the strongest of the laryngeal cartilages, and is shaped like a signet ring. The flat portion of the ring or lamina is located posteriorly and extends upward to form the posterior border of the larynx. Since the cricoid cartilage forms the only complete annular support of the laryngeal skeleton, its preservation is essential for the maintenance of the enclosed airway.

1 In the adult, the cricoid cartilage is at the level of C-6, C-7 and in the child at the level of C-3, C-4.

Posterolaterally, the cricoid articulates with the inferior cornua of the thyroid cartilage with which it shares true synovial joints. These joints permit a rocking action of the cricoid cartilage on the thyroid cartilage and also a slight anteroposterior sliding motion. Also through synovial joints, the cricoid cartilage on its posterosuperior aspect supports the two arytenoid cartilages.

Epiglottis

The epiglottis (fibroelastic cartilage) is a leaf-shaped structure attached to the inside of the thyroid cartilage anteriorly and projecting upward and backward above the laryngeal opening. The petiole is the small, narrow portion of the epiglottis that is attached to the thyroid cartilage.

Arytenoid Cartilages

The arytenoid cartilages (mostly hyaline cartilages) are much smaller in size, yet they are primarily responsible for the opening and closing of the larynx. Roughly pyramidal in shape, they rest on the upper edge of the cricoid lamina at the posterior border of the larynx. The anterior projection of each arytenoid, or vocal process, receives the attachment of the posterior or mobile end of each vocal cord. The lateral prominence of each arytenoid cartilage is known as the muscular process because of the insertion of numerous muscles. The arytenoids articulate with the cricoid cartilage at the cricoarytenoid joint, which permits a wide range of motion in three directions.

Corniculate Cartilages

The corniculate cartilages (fibroelastic cartilages), also called cartilages of Santorini, are small cartilages above the arytenoid and in the aryepiglottic folds.

Cuneiform Cartilages

The cuneiform cartilages (fibroelastic cartilages), also called cartilages of Wrisberg, are elongated pieces of small yellow elastic cartilages in the aryepiglotic folds.

Triticeous Cartilage

The triticeous cartilage (cartilage triticea) is a small elastic cartilage in the lateral thyrohyoid ligament. When calcified, it could be mistaken for a foreign body on the soft tissue x-ray film.

Ossification

1. Thyroid cartilage ossifies at 20-30 years of age. Ossification begins in the inferior margin and progresses cranially.

2 2. Cricoid cartilage ossifies after the thyroid cartilage. The first part to be calcified is the superior portion and could be mistaken for a foreign body. Calcification progresses caudally.

3. Arytenoid cartilages calcify at the third decade.

4. The hyoid ossifies from six centers shortly after birth and is completed by 2 years of age.

Laryngeal Ligaments and Membrane

Extrinsic

The extrinsic ligaments of the larynx bind the cartilages to the adjoining structures and to one another, and round out the laryngeal framework.

1. Thyrohyoid membrane and ligaments attach the thyroid cartilage to the hyoid bone. The thyrohyoid membrane is pierced on each side by: (a) superior laryngeal vessels; (b) internal branch of superior laryngeal nerve. Median thyrohyoid ligament is the thickened median portion of the thyrohyoid membrane. Lateral thyrohyoid ligament forms the thickened posterior border of the thyrohyoid membrane on each side, and the cartilago triticea is often found in this ligament.

2. Cricothyroid membrane and ligaments connect the thyroid and cricoid cartilages. This ligament may be pierced for emergency tracheotomy (cricothyrotomy) with little fear of bleeding. However, because of the proximity of the vocal cords, this space should not be used for prolonged tracheal intubation since scar tissue may be produced to interfere with the mobility of the cords.

3. The cricotracheal ligament attaches the cricoid cartilage to the first tracheal ring.

4. The epiglottis is suspended in position by membranous connections to the hyoid bone, the thyroid cartilage, and the base of the tongue.

Intrinsic

The intrinsic ligaments unite the cartilages of the larynx and perform an important role in the closure of this organ.

1. The elastic membrane of larynx is the fibrous framework of the larynx. It lies beneath the laryngeal mucosa and is divided into upper and lower parts by the ventricle of the larynx.

2. The quadrangular membrane is the upper part of the elastic membrane of the larynx, extending from the lateral margin of the epiglottis to the arytenoid and corniculate cartilages, and inferiorly to the false cord. It forms part of the wall between the upper pyriform sinus and the laryngeal vestibule. The quadrangular membrane and the conus elasticus are separated by the ventricle of Morgagni.

3 3. Conus elasticus (cricovocal membrane) is the name given to the lower part of the elastic membrane of the larynx. It is composed mainly of yellow elastic tissue. It is attached to:

a. Inferiorly: Superior border of the cricoid cartilage. b. Superoanteriorly: Deep surface of angle of the thyroid cartilage. c. Superoposteriorly: Vocal process of the arytenoid cartilage.

4. The median cricothyroid ligament is formed by the thickened bottom part of the conus elasticus.

5. The vocal ligament which forms the framework of the vocal cord is the free upper edge (the strongest part) of the conus elasticus.

6. The thyroepiglottic ligament attaches the epiglottis to the thyroid cartilage.

Cavity of the Larynx

1. The cavity of the larynx is divided into three parts:

a. Vestibule. b. Ventricle. c. Subglottic space

by two folds of mucous membrane:

a. False cords. b. True cords.

2. The vestibule lies between the inlet and the edges of the false cords and is bordered by:

Anteriorly: Posterior surface of the epiglottis. Posteriorly: Interval between the arytenoid cartilages. Laterally: Inner surface of the aryepiglottic folds and upper surfaces of the false cord.

3. The ventricle of the larynx (ventricle of Morgagni) is a deep, spindle-shaped recess between the false and true cords, and lined by a mucous membrane which is covered externally by the thyroarytenoid muscle.

4. The saccule is a conical pouch which ascends from the anterior part of the ventricle. It lies between the inner surface of the thyroid cartilage and the false cord. Numerous mucous glands open on to the surface of its lining mucosa for lubricating the vocal cords.

5. The glottis (rima glottidis) is the space between the free margin of the true vocal cords. This space is wide and triangular in shape when the vocal cords are abducted (as in respiration), but assumes a slitlike appearance during adduction of the cords (in phonation).

4 The posterior glottic chink in the adult is 18-19 mm. In the newborn it is 4 mm. The total glottic chink in a newborn is 14 mm.

6. The subglottic space lies between the true vocal cords and the lower border of the cricoid cartilage.

7. The preepiglottic space is a wedge-shaped space lying in front of the epiglottis and bounded by:

Anteriorly: Thyrohyoid membrane. Anterosuperiorly: Hyoid. Superiorly: Vallecula. Posteriorly: Part of the epiglottis. Laterally: Hyoepiglottic ligament.

8. The false cords (ventricular bands) are the upper set of two horizontal folds on each side of the laryngeal cavity and extend from the angle of the thyroid cartilage anteriorly to the bodies of the arytenoid cartilages posteriorly, and have a primitive constricting function.

9. The true cords (the lower set) are directly concerned with the production of voice and with the protection of the lower respiratory passages. These folds stretch from the angle of the thyroid cartilage anteriorly to the vocal processes of the arytenoid cartilages posteriorly. They enclose the vocal ligament and a major portion of the vocalis muscle. The covering epithelium is closely bound down to the underlying vocal ligament, and the blood supply is poor. Hence the pearly white appearance of the vocal cords in life.

Laryngeal Joints

Cricothyroid Joint

The cricothyroid joint is a synovial joint with a capsular ligament between the inferior cornu of the thyroid cartilage and the facet on the cricoid cartilage at the junction of arch and lamina. Two movements occur:

1. Rotation: Through a transverse axis. 2. Gliding: Slightly.

Cricoarytenoid Joint

The cricoarytenoid joint is a synovial joint with a capsular ligament between the base of the arytenoid cartilage and the facet on the upper border of the lamina of the cricoid cartilage. Two movements occur:

1. Rotation: Of the arytenoid, on a vertical axis. The vocal process moves medially or laterally. 2. Gliding: The arytenoids move toward or away from each other. A strong posteior cricoarytenoid ligament prevents excessive movements of the arytenoid on the cricoid.

5 Laryngeal Muscles

1. The extrinsic muscles of the larynx are concerned with the movement and fixation of the larynx as a whole and consist of levator and depressor groups.

The depressor group consists of:

1. Sternohyoid (C-2, C-3). 2. Thyrohyoid (C-1). 3. Omohyoid (C-2, C-3).

The elevator group consists of:

1. Geniohyoid (C-1). 2. Digastrics (anterior, cranial nerve V and posterior VII). 3. Mylohyoid (V). 4. Stylohyoid (VII).

2. The middle constrictor muscle is attached to the greater cornua of the hyoid bone. The inferior constrictor muscle is attached to the oblique lines of the thyroid cartilage and to the cricoid cartilage. These muscles influence the position of the larynx during phonation.

3. The intrinsic muscles of the larynx are directly concerned with its protective and phonatory functions, and consist of one unpaired muscle, the transverse arytenoid, and four paired muscles which act on the cricoarytenoid and cricothyroid joints, respectively.

1. Interarytenoid muscle (unpaired).

a. Transverse. b. Oblique.

2. Posterior cricoarytenoid muscle (paired).

3. Lateral cricoarytenoid muscle (paired).

4. Thyroarytenoid muscle (paired).

5. Cricothyroid muscle (paired).

4. The interarytenoid muscle is unpaired and consists of transverse and oblique fibers connecting the bodies of two arytenoid cartilages. This muscle is innervated bilaterally by the recurrent laryngeal nerve and therefore is not paralyzed by unilateral recurrent nerve disease. Action: Approximation of arytenoids and closure of glottis.

5. The posterior cricoarytenoid muscle passes from the posterior surface of the cricoid lamina to the muscular process of the arytenoid cartilage. Action: Lateral rotation of arytenoids and abduction of vocal cords (main abductor).

6 6. The lateral cricoarytenoid muscle passes from the cricoid arch to the muscular process of the arytenoid cartilage. Action: Medial rotation of arytenoids and adduction of vocal cords.

7. The thyroarytenoid or vocalis muscle arises from the inner aspect of the thyroid angle anteriorly and inserts into the vocal ligament and into the arytenoid cartilage. Action: Fine control of the vocal cords - relaxation of cord, firming of edge, changing of mass, etc.

8. The cricothyroid muscle arises from the arch of the cricoid anteriorly, and inserts into the inferior horn and body of the thyroid cartilage above. It elevates the arch of the cricoid cartilage as a lever, and thus tilts the lamina with the attached arytenoid cartilages posteriorly. Action: Elongation and tension of the cords (chief tensor).

Recent data suggest this muscle plays a major role in the overall regulation of breathing by its control of expiratory resistance and flow. Cricothyroid contraction in expiration results in vocal elongation increasing glottic size. Such a mechanical effect reduces airway resistance and shortens expiratory duration.

9. Laryngeal movements:

Abduction: Posterior cricoarytenoid.

Adduction:

a. Lateral cricoarytenoid. b. Transverse portion of interarytenoid. c. Thyroarytenoid.

Tension:

a. Cricothyroid (chief tensor). b. Thyrarytenoid or vocalis (internal tensor).

Mucous Membrane of the Larynx

1. Stratified squamous epithelium is found over:

a. Vocal cords. b. Upper part of vestibule of larynx.

2. Ciliated columnar epithelium lines the remainder of the cavity.

3. Mucous glands are found in:

a. Ventricles and sacculi. b. Posterior surface of epiglottis. c. Margins of aryepiglottic folds. There are none on the free edges of the vocal cords.

7 4. Reinke's layer of connective tissue lies immediately under the epithelium of the larynx and superficial to the elastic layer. There are no glands beneath it and no lymph vessels in it.

Nerve Supply

1. The larynx is supplied by two branches of vagus nerve: superior laryngeal and inferior (recurrent) laryngeal nerves.

2. The superior laryngeal nerve (SLN) divides extralaryngeal into:

a. Internal branch (sensory). b. External branch (motor and sensory).

The larger internal branch supplies sensory innervation to those areas of the larynx above the glottis. The smaller external branch gives motor innervation to the cricothyroid muscle and sensory supply to the anterior infraglottic larynx at the level of the cricothyroid membrane.

3. The recurrent (or inferior) laryngeal nerve (RLN) supplies motor innervation to all the intrinsic laryngeal muscles of the same side except for the cricothyroid and to the interarytenoid muscle of both sides. It also supplies sensory innervation to those portions of the larynx below the glottis.

4. The recurrent laryngeal nerve has a much longer course on the left side than on the right. On the left side it turns around the arch of the aorta. On the right side it turns around the subclavian artery. In the neck it lies between the trachea and esophagus as it approaches the larynx. Its terminal part passes upwards, under cover of the ala of the thyroid cartilage, immediately behind the inferior cricothyroid joint.

5. Each nucleus ambiguus is the somatic motor nucleus of the 9th, 10th, and 11th nerves.

6. The nucleus ambiguus is supplied by the posterior inferior cerebellar artery (branch of the vertebral) and the anterior inferior cerebellar artery (branch of the basilar).

8 Blood Supply

Upper Larynx

1. External carotid artery. 2. Superior thyroid artery. 3. Superior laryngeal artery.

Lower Larynx

1. Subclavian artery. 2. Thyrocervical artery. 3. Inferior thyroid artery. 4. Inferior laryngeal artery.

Venous Drainage

Upper Larynx

1. Superior laryngeal vein. 2. Superior thyroid vein. 3. Internal jugular vein.

Lower Larynx

1. Inferior laryngeal vein. 2. Inferior thyroid vein. 3. Innominate vein.

Lymphatic Drainage

1. The lymphatic drainage from the larynx drain mainly into the deep cervical group of lymph nodes. It is of great clinical importance that the vocal cords themselves contain scarcely any lymphatic channels.

2. The lymphatic network of the supraglottic structures is extensive. The channels collect in a pedicle at the anteriro end of the aryepiglottic fold, pass laterally, anterior to the anterior wall of the pyriform fossa, and leave the larynx with the neurovascular bundle through the thyrohyoid membrane. Almost all (98%) of the channels end in the upper deep cervical nodes between the digastric tendon and the omohyoid muscle. The remainder pass to the lower cervical chain or the spinal accessory chain.

3. The lymphatics of the infraglottic area have a more variable drainage pattern than those of the supraglottic network. The channels leave the area in three pedicles. The anterior pedicle passes through the cricothyroid membrane and many vessels end in the prelaryngeal (Delphian) nodes in the region of the thyroid isthmus. Channels then leave these nodes with the remaining anterior channels to travel to the deep inferior cervical nodes. The two posterolateral pedicles leave the larynx through the cricotracheal membrane with some

9 channels going to leave through the cricotracheal membrane to the paratracheal chain of nodes, while others pass to the inferior jugular chain.

4. Generally, lymphatic drainage from each half of the larynx is quite separate and little crossover or mixing occurs.

5. There is evidence that lymphatic channels do cross the midline in the supra- and infraglottic areas. Contralateral drainage is more likely to occur spontaneously from the infraglottic areas, thus lesions of this area may be associated with less consistent patterns of metastases.

Physiology of the Larynx

Basic Funtions

Three basic functions of the larynx in order of importance are: protection, respiration, and phonation.

1. Protection by the larynx as a sphincter prevents the entrance of anything but air into the lung.

a. Closure of the laryngeal inlet. b. Closure of the glottis. c. Cessation of respiration. d. Cough reflex, expulsion of secretions and foreign bodies.

2. Respiration governed by active muscular dilatation of the laryngeal aperture assists in the regulation of gaseous exchange with the lung and in the maintenance of acid-base balance.

3. Phonation is voice produced by the vibration of the vocal cords.

4. Other functions: Fixation of the chest is also a function of the larynx. Closure of glottis will help to increase intrathoracic and intra-abdominal pressure and aid in lifting, digging, defecation, vomiting, urination, or childbirth.

The protective function of the adult human larynx is admittedly precarious by virtue of its low position in the neck.

The human newborn exhibits a nasolaryngeal connection by approximation of the epiglottis with the posterior surface of the palate, thereby ensuring against aspiration by forming a continuous upper and lower airway. Obligate nasal breathing in the newborn period (1-6 months) is related to this anatomic configuration.

The epiglottis in the adult serves as a laryngeal shield to direct swallowed food laterally into the pyriform fossae and away from the midline laryngeal aperture. This protective function is enhanced by elevation of the larynx toward the nasal cavity during the

10 height of deglutition. The corniculate and cuneiform cartilages are contained in the aryepiglottic folds to provide stiffness and support to these structures.

Due to their structural configuration the false cords prevent the egress of air from the lungs (provides an expectorative function) whereas the true cords with their upturned margins are capable of impeding its ingress (protective function).

Neuromuscular Physiology

Afferent System

The density of sensory innervation is greatest in the laryngeal inlet and especially the laryngeal surface of the epiglottis, an observation consistent with its protective function of the distal respiratory tract. Afferent impulses are delivered through the ganglion nodosum to the brain stem tractus solitarius.

Efferent System

Motor distribution to the intrinsic laryngeal musculature originates in the medullary nucleus ambiguus. Each RLN innervates all muscles except for the cricothyroideus which is supplied by the external division of the SLN. The interarytenoid muscles receive bilateral motor innervation from both RLN.

The sole abductor is the posterior cricoarytenoid which is a muscle extending from the posterior aspect of the cricoid plate to the muscular process of the arytenoid. The major laryngeal adductors are the thyroarytenoid and lateral cricoarytenoid muscles. The cricothyroid muscle adducts and tenses the vocal cord, passively lengthening it by 30%. The interarytenoid muscles close the posterior gap in the glottis.

Paralysis of the SLN leads to denervation of the ipsilateral cricothyroid muscle, resulting in rotation of the posterior commissure toward the inactive side from unopposed contraction of the contralateral cricothyroid muscle. RLN injury results in a paramedian vocal cord position because of the adductor action of the intact SLN contracting the ipsilateral cricothyroid muscle.

Neurophysiology of Protective Function

Man does not possess a crossed adductor reflex, i.e. stimulation of one SLN does not produce simultaneous activation of the contralateral adductor musculature. Therefore, unilateral SLN paralysis may lead to aspiration (failure of ipsilateral cord closure) despite the integrity of both RLN.

There are three sphincteric tiers of airway protection:

1. Contraction of the superior division of the thyroarytenoid muscles contained in the aryepiglottic folds.

2. Contraction of middle thyroarytenoid fibers in the false cords.

11 3. Contraction of inferior division of the thyroarytenoid at the level of the true cord. This is the most significant barrier to aspiration owing to the upturned border of the cord margin.

Stimulation of the SLN, as well as all major cranial afferent nerves, special sensory, and spinal somatic sensory nerves, produces strong laryngeal adductor responses, emphasizing the primitive role of respiratory protection from a wide variety of potentially noxious stimuli. Laryngeal spasm is solely mediated by the SLN. SLN stimulates also produces inhibition of laryngeal abductor activity, resulting in various degrees of reflex apnoea.

Neurophysiology of Respiratory Function

Widening of the glottis occurs with rhythmic bursts of activity in the RLN. The glottis opens a fraction of a second before air is drawn in by the descent of the diaphragm. Electromyogram studies show that phasic inspiratory abduction, via muscular contraction of the posterior cricoarytenoids, is synchronous with respiration. The degree of abductor activity varies directly with the degree of ventilatory resistance (i.e. decreases with tracheotomy). Phasic inspiratory contraction of the cricothyroid muscle (vocal cord adductor and isotonic tensor) increases the anteroposterior diameter of the glottic chink. Therefore, both the posterior cricoarytenoid and cricothyroid muscles are driven by the medullary respiratory center.

Neurophysiology of Phonation

Speech results from the production of a fundamental tone produced at the larynx and is modified by resonating chambers of the upper aerodigestive tract. The vocal folds are positioned near the midline by isotonic tensing of the cricothyroid muscles. The thyroarytenoid muscles provide finer isometric modifications.

As pitch increases the true cords lengthen and tense isotonically through the action of the cricothyroid muscles. Cord thinning is produced by thyroarytenoid action which increases internal tension of the true cord. Extrinsic laryngeal muscles also may affect pitch (i.e. sternothyroid).

Laryngeal Voice Production

Myoelastic-Aerodynamic Theory. During expiration the air current flowing through the glottis is unidirectional and the vocal cords vibrate in an alternating mode. The sequence of events is as follows: The laryngeal muscles first position the vocal cords (various degrees of adduction) and place them under the appropriate longitudinal tension. Next muscular and passive forces of exhalation cause the subglottic air pressure to increase. Subglottic air pressure reaches a point where it exceeds muscular opposition and the glottic chink is forced open. When the vocal cords start opening from complete closure, they open in a posterior to anterior direction. Thus the posterior portion of the glottis is the firs to open, first to reach maximum excursion and first to recontact each other at the end of a vibratory cycle. After the release of the puff of air there is a reduction of subglottic pressure and the vocal cords approximate each other again. The myoelastic forces of the vocal cords exceed the aerodynamic forces. The myoelastic forces are enhanced because air current flowing through

12 a narrow channel exerts a negative pressure upon the channel walls (Bernoulli's effect). The vocal cords are thus sucked back together in an adducted state until the subglottic air pressure can overcome the myoelastic forces of the reapproximated cords, and the cycle is thereby repeated.

The resulting waveform of the vocal cords is not sinusoidal but sawtooth in type, and can be classified as a relaxation oscillator. An unvoiced output (glottis opened) is essentially a noise.

Neuromuscular or Neurochronaxic Theory. This theory, now disproved, suggested that each new vibratory cycle was initiated by central neuronal impulses via the vagus nerve to the appropriate laryngeal muscles. According to this theory the rate of impulses delivered to the larynx will determine the frequency of vocal cord vibration. Physiologic and audiometric analysis have led us to believe that this theory is untrue (i.e. voice is still produced in a patient with bilateral vocal cord palsy).

Components of Human Vocal Mechanism

1. Activator: Energy produced by the expiratory phase of the breathing apparatus. 2. Generator: Glottis vibrates at different frequencies. 3. Resonator: Sound modulation occurring in supraglottis, nasopharynx, oropharynx, and nasal chambers. 4. Articulators: Precise movements of palate, tongue, teet, and lips used to mold different sounds.

Glottic Closure Reflex - Control Mechanisms

Reflex laryngeal closure is produced by rapid contraction of the thyroarytenoid (TA) muscle in response to SNL stimulation. Exaggerated reflex glottis closure leads to laryngospasm which is maintained well beyond the cessation of mucosal irrigation. Obstructive apnea secondary to prolonged laryngospasm may produce death by acute hypoxia and hypercapnia. The body's fail-safe mechanism in dealing with this phenomenon is that laryngospasm is inhibited by (1) increased arterial PCO2, (2) decreased arterial PO2, (3) positive intrathoracic pressure, and (4) inspiratory phase of respiration. The most common causes of laryngospasm are inhaled irritants, manipulation of the upper aerodigestive tract (i.e. extubation), foreign bodies, and mucus or blood in the glottic chink.

Arrhythmia, bradycardia, and occasionally cardiac arrest may result from stimulating the larynx. The mechanism appears to be related to stimulation of nerve fibers which arise in aortic baroreceptors, and in some individuals, travel to the central nervous system by way of the recurrent laryngeal nerve, ramus communicans, and superior laryngeal nerve. These can result from light anesthesia, prolonged laryngoscopy, repeated attempts at intubation, respiratory obstruction, and tracheal irritation. The reflex cardiac effects can be controlled by atropine and enhanced by morphine.

13 Selected Disorders of the Larynx

Inflammatory Diseases

Acute Epiglottitis

Acute epiglottitis is a special form of rapidly progressing acute laryngitis in which the inflammatory changes primarily involve the epiglottis. It occurs mainly in children aged 2-7 years, although infants, older children, and even adults may be affected.

Etiology: Haemophilus influenzae type B

Symptoms:

1. Rapidly progressive dyspnea, especially in children. May be fatal within a few hours of onset unless immediately diagnosed and treated. This is a medical emergency!

2. Dysphagia starts with sore throat, difficulty in swallowing, then refusal of oral feedings.

3. Dehydration, fever, tachycardia, restlessness, exhaustion with respiratory and circulatory collapse.

4. The voice usually is not hoarse but may present with a "hot potato voice".

5. Patient prefers upright position and leaning slightly forward. Do not place the patient in a recumber position.

6. The most important clinical feature is the swollen, bright red epiglottis obstructing the pharynx at the base of the tongue.

7. A patient who is already in extreme respiratory distress may develop a total airway obstruction when an attempt is made to visualize the epiglottis. A quick look at the epiglottis in the emergency room with a tongue blade is to be condemned. Lateral x-ray of the neck is preferable to direct examination and will show an enlarged epiglottis.

8. Blood culture usually shows H. influenzae type B.

Treatment:

In the past decade, changes have occurred in the management of acute epiglottitis. Recent data suggest that nasotracheal intubation is the preferred method of treatment for acute epiglottitis over tracheotomy. The following steps of management are recommended:

1. The patient suspected of acute epiglottitis should be evaluated in the emergency room by a team consisting of a pediatrician, anesthesiologist, and otolaryngologist.

14 2. A lateral extended neck x-ray is obtained with a physician in attendance. Oral examination with a tongue depressor is not advised.

3. The patient is immediately taken to the operating room if the x-ray is diagnostic or progressive epiglottitis is suspected.

4. Orotracheal intubation is performed with both an anesthesiologist and an otolaryngologist present and prepared for immediate bronochoscopy and/or tracheotomy.

5. The otolaryngologist examines the epiglottis by direct laryngoscopy and the epiglottis and blood are cultured. The endotracheal tube is then replaced by a nasotracheal tube which is firmly secured by a tape and a string around the neck.

6. The patient is transferred to the ICU for close observation. Restraints to prevent accidental self-extubation may be needed.

7. Ampicillin 200-400 mg/kg and chloramphenicol, 50-100 mg/kg daily are administered intravenously. Hydration is managed by intravenous fluids. Frequent nasotracheal suction is needed.

8. Steroids may be of value in limiting the progression of inflammation and edema.

9. Extubation is done 24-48 hours after intubation if direct laryngoscopy at bedside shows a decrease in the supraglottic edema.

10. The patient is observed for an additional 24-48 hours and discharged with appropriate antibiotic therapy for a total of 10 days.

11. It is important to emphasize that the skilled nursing staff familiar with the management of acute cardiorespiratory problems is necessary following nasotracheal intubation, and that the anesthesiologist and otolaryngologist should always be available in the even of self-extubation. In an institution where the special 24-hour pediatric ICU is not available, it is safer to rely on the time-tested tracheotomy.

12. Since complete obstruction can occur with alarming suddenness, nasotracheal intubation or tracheotomy should be performed as soon as the diagnosis of acute epiglottitis is made.

Acute Laryngotracheobronchitis

Laryngotracheobronchitis is an acute infection of the lower respiratory passages, extending from the larynx down into the smalled subdivisions of the bronchial tree. It is endemic throughout the year, but may react in epidemic proportions in any locality during the winter season.

Etiology: Probably a virus. Parainfluenza types 1-4 have been isolated frequently. Haemophilus influenzae, streptococcus, staphylococcus, and pneumococcus are commonly cultured. The disease occurs in children, especially between the ages of 1-3 years.

15 Pathology: A descending inflammation of the mucous membrane lining the lower respiratory tract, followed by congestion, edema, and exudation of a thick tenacious secretion. Anatomically, the conus elasticus is the most involved site.

Symptoms:

1. At the onset, the disease is like an ordinary cold except for the early presence of a croupy cough. 2. Hoarseness is noted shortly thereafter. 3. As the swelling increases, inspiratory stridor develops. 4. Retractions then occur. 5. Circumoral pallor and cyanosis usually precede a decrease in breath sounds that, in turn, is an indication that death may be imminent. Immediate establishment of an airway is mandatory. 6. In addition to these symptoms of respiratory embarrassment, anorexia and fever are common in the early stages while restlessness, dehydration, and exhaustion may be noted later. 7. Agitation, increased pulse (to 140), and respiration rate (to 80) are signs of increasing levels of CO2.

Treatment:

1. Hospitalization and close observation. 2. Ultrasonic humidification (a most important treatment). 3. Antibiotics (ampicillin 150 mg/kg/day). 4. Racemic epinephrine via intermittent positive pressure breathing (IPPB). 5. Corticosteroids (100 mg hydrocortisone IM on admission) may be helpful. 6. Sedation is contraindicated since it may compromise the airway. 7. Parenteral fluids. 8. Oxygen. 9. Timely nasotracheal intubation or tracheotomy. When in doubt, do it. Progressive retraction associated with agitation, cyanosis, lethargy, increased pulse (to 140), respiration rate (to 80), and CO2 level is an indication for immediate nasotracheal intubation or tracheotomy.

Tuberculous Laryngitis

Etiology: Almost always secondary to active pulmonary tuberculosis.

Pathology:

1. Cellular infiltration. 2. Proliferation and nodular function. 3. Granulation tissue in the interarytenoid fold. 4. Perichondritis, cartilage necrosis. a. Multiple small superficial ulcers in the interarytenoid fold, false and true cords, and the epiglottis. b. Perichondritis and cartilage necrosis.

16 Symptoms:

1. Hoarseness. 2. Cough, late, with production of blood streaked sputum. 3. Pain and referred earache are fairly common. 4. In advanced cases, dyspnea from edema of the larynx and scar contraction or destruction of underlying cartilages. 5. Biopsy is essential for diagnosis to rule out malignancy. The tuberculous granuloma similar to that of pemphigoid is subepithelial. The pemphigus involvement is intraepithelial. 6. The most common site of tuberculosis of the larynx is the posterior larynx (interarytenoid fold). The next most common site is the laryngeal surface of the epiglottis.

Prognosis: If diagnosed and treated early, prognosis is good. If the local manifestations include cartilaginous involvement, the prognosis is more serious, since irreparable harm may have been inflicted upon the framework or soft tissues of the larynx.

Treatment:

1. Streptomycin and para-aminosalicylic acid. 2. Treatment of pulmonary lesion. 3. Voice rest. 4. Narcotics for pain. 5. Injection of the superior laryngeal nerve with procaine (Novocaine) or alcohol for relief of pain. 6. Tracheotomy for obstruction. 7. Surgery for secondary stenosis, if indicated.

Syphilitis Laryngitis

Etiology: Treponema pallidum. Extremely rare in the congenital form and now very rare also in the acquired form of the disease.

Pathology: The larynx is never affected in the primary stage of the disease. During the secondary stage, infection and mild edema of the larynx are common and mucous patches may be observed. These lesions are temporary and disappear with the resolution of this phase. The gummata are characteristic of laryngeal involvement in the tertiary stage. Ultimate breakdown of these lesions results in the development of ulcerations, perichondritis, and fibrosis.

Symptoms:

1. A mild hoarseness is often the only symptom. Gummata and ulcerations may lead to varying degrees of hoarseness. 2. There is no pain. 3. As the swelling increases or fibrosis develops, symptoms of respiratory embarrassment may occur. 4. The diagnosis is confirmed by serologic tests and biopsy.

17 Prognosis: In early lesions, the prognosis is quite favorable, but destruction of cartilages cause permanent changes.

Treatment:

1. Penicillin. 2. Supportive measures. 3. Tracheotomy for respiratory obstruction. 4. Reconstructive operation for severe laryngeal disease.

Sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown etiology. It affects primarily the lung and mediastinal nodes but laryngeal involvement may occur in 1-5% of all patients with sarcoidosis.

Pathology: The lesion is characterized by noncaseating granuloma. The lack of caseation distinguishes sarcoid from tuberculosis, pathologically. Since the disease occurs submucosally, ulcerations are rare.

Symptoms:

1. Hoarseness is the prominent feature. 2. Pain usually is not present. 3. If the lesion is large, dyspnea may be present. 4. The epiglottis is most often involved, typically with small nodules at the free margin, which can become a confluent, indurated swelling. Other areas commonly affectged are the aryepiglottic folds, arytenoids, false cords, and subglottic areas. The true vocal cords are rarely involved. 5. Both diffuse edema and exophytic masses may cause airway obstruction. 6. Biopsy is essential for diagnosis.

Prognosis: Permanent clinical remission usually occurs.

Treatment:

1. Systemic and/or local injection of steroids may relieve obstruction by decreasing edema. 2. Radiation is not effective. 3. Tracheotomy, with surgical removal of bulky obstructing lesions, is a safe, conservative approach.

Etiology: Klebsiella rhinoscleromatis (von Frisch bacillus). Rare in the USA.

18 Symptoms:

1. Hoarseness, cough, and increasing dyspnea. 2. The most common site of scleroma of the larynx is the subglottic region. Pale pinkish swelling may be seen below the vocal cords.

Treatment:

1. Streptomycin. 2. Steroids. 3. Tracheotomy (often needed).

Perichondritis of the Larynx

Etiology:

1. Infection (tubercluosis, syphilis, septic laryngitis, etc). 2. Trauma. 3. High tracheotomy. 4. Radiotherapy. 5. Neoplasm with secondary infection.

Pathology:

1. Perichondritis leads to subperichondrial abscess, necrosis of cartilage, and later, stenosis.

2. Perichondritis of the thyroid cartilage is more common than perichondritis of the epiglottis. This is because the epiglottis is fibroelastic cartilage where the perichondrium is adhered to the cartilage.

Symptoms:

1. May be insidious or of sudden onset. 2. Fever and malaise (acute form). 3. Local pain and tenderness. 4. Enlargement of laryngeal framework, swelling of the neck. 5. Abscess and fistula. 6. Hoarseness, cough, dysphagia, and dyspnea.

Diagnosis:

1. Syphilis and malignant disease should be ruled out. 2. Rule out unsuspected foreign body.

19 Treatment:

1. Hospitalization. 2. Systemic antibiotics. 3. Tracheotomy. 4. I and D if indicated. 5. Dilatation for stenosis. 6. Laryngofissure. 7. Laryngectomy for extensive necrosis of a cartilage.

Glanders

Glanders is a serious infectious disease marked by the occurrence of multiple granulomatous abscesses throughout the body, caused by Pseudomonas mallei (Actinobacillus mallei). Perichondritis and cartilage destruction may complicate the laryngeal disease.

Leprosy of the Larynx

Leprosy of the larynx is rare. It affects the larynx in 10% of the cases. It is caused by Mycobacterium leprae or Hansen's bacillus.

Treatment:

1. DDS (Diaminophenylsulfone; dapsone) (for 1-4 years). 2. Steroids. 3. Tracheotomy.

Diphtheric Laryngitis

Diphtheric laryngitis is rare.

Etiology: Corynebacterium diphtheriae.

Symptoms:

1. Onset insidious. 2. Hoarse, croupy cough is the first symptom. 3. Grayish white membrane on the larynx. Its removal is followed by bleeding.

Treatment:

1. Antitoxin. 2. Penicillin. 3. Tracheotomy.

20 Mycotic Infection of the Larynx

Fungal infections of the larynx are rare. Blastomycosis, histoplasmosis, and candidiasis are the most commonly encountered.

Blastomycosis. Blastomycosis is seen in endemic proportions in North America and is mainly a disease of the skin and lungs. However, primary involvement of the larynx does occur. It is caused by Blastomyces dermatitidis and characterized by diffuse nodular infiltration of the larynx, vocal cord fixation, ulcer, and stenosis.

The epithelium undergoes marked hyperplasia of the pseudoepithelial type and may be mistaken for carcinoma. Microabscesses contains the organisms, giant cells, and mononuclear cells occur in the epidermis and dermis and are characteristic of this disease.

Symptoms:

1. Hoarseness and cough occur early. 2. Dyspnea and dysphagia are late symptoms. 3. In the early stage, the laryngeal mucosa is difusely inflamed and granular. 4. Tiny miliary nodules may be seen on the vocal cords. 5. In advanced stage, mucosal ulceration, covered with foul smelling, greenish exudate, under which is a bright red granular bed. 6. Later, fibrosis, fixation of arytenoids, or stenosis develops.

Treatment: Amphotericin B.

Histoplasmosis. Histoplasmosis is caused by Histoplasma capsulatum and usually associated with pulmonary histoplasmosis.

Treatment:

1. Amphotericin B. 2. Sulfonamide.

Candidiasis (moniliasis). This is caused by Candida albicans, and is almost always the result of chemotherapeutic suppression of normal bacterial flora. It is characterized by white patches on a bright red mucosa.

Treatment: Nystatin (Mycostatin).

Actinomycosis. This disease, caused by Actinomyces bovis is characterized by a yellowish granulomatous infiltration which suppurates. It involves the neck and perilaryngeal structures.

Treatment: Penicillin or tetracycline.

21 Coccidiomycosis. Caused by Coccidioides immutus, this disease is endemic in the San Joaquin Valley area of California. It is more often seen in colored races. The lesion consists of nodular masses of granulomatous tissue.

Benign Tumors and Cysts of the Larynx

Benign Tumors

Benign tumors of the larynx are relatively uncommon. They occur in the following order of frequency: papilloma, chondroma, neurofibroma, leiomyoma, angiofibroma, myoma, hemangioma and chemodectoma.

Papilloma. Papilloma is the most common benign tumor of the larynx, and occurs in patients of all ages.

Etiology:

1. The causative agent is thought to be a virus. 2. Seems to be related to hormonal changes. Papillomas usually regress during puberty.

Pathology:

1. Papillary epithelial tumor usually involving the true cords, but may affect supraglottic and subglottic regions. 2. May also involve the trachea and bronchus. 3. Papilloma in juveniles is more often multiple, and recurs more frequently than that in adults. 4. Papillomas in adults are usually single, but may undergo malignant change.

Symptoms:

1. Aphonia or weak cry is usually the first sign in infants. 2. Dyspnea. 3. Patients with papilloma have low serum magnesium.

Treatment:

1. Repeated laryngoscopic removal to maintain an adequate airway is currently the standard treatment. 2. Tracheotomy is occasionally necessary. 3. Cryosurgery. 4. Autogenous vaccine. 5. Exogenous leukocyte interferon therapy has been proposed by Haglund. 6. Ultrasound therapy. 7. In view of a high incidence of recurrence, thyrotomy and pharyngotomy are not indicated. 8. Irradiation is contraindicated because of its carcinogenic effects. 9. Laser surgery.

22 Chondroma. Chondroma is a slow growing lesion, composed mainly of hyaline cartilage. It affects males more often than females (10:1).

The most frequent site of origin is the internal aspect of the posterior plate of the cricoid cartilage, followed by the thyroid, arytenoid, and epiglottis.

Symptoms:

1. Hoarseness, dyspnea, and dysphagia (in that order) are the presenting symptoms. 2. A full sensation within the throat may be present. 3. The symptoms are insidious. 4. Dyspnea and hoarseness are prominent with a subglottic mass arising from the internal aspect of the cricoid. 5. The dysphagia is more common in lesions arising from the posterior aspect of the cricoid. 6. Hoarseness is due to restriction of cord mobility by the mass. 7. A mirror examination shows a smooth, firm, round, or nodular, fixed tumor covered by normal mucosa. 8. Chondroma of the thyroid, cricoid, or tracheal cartilages may present as a hard neck mass. 9. A soft tissue film, laminogram, and laryngogram will delineate the extent and site of lesion. 10. Calcification is commonly seen on X-ray.

Treatment:

1. Excision: The site of origin determines the approach. 2. Thyrotomy for tumors of the anterior aspect of the cricoid. 3. A lateral external approach, with or without pharyngotomy, for chondromas of the thyroid, posterior aspect of cricoid, or arytenoid. 4. Recurrence is common if the tumor is not removed completely. Peroral removal is not advised. 5. Total laryngectomy may be necessary for treatment of recurrences. 6. Reconstruction of cricoid cartilage defect by suturing the inferior cornu of the thyroid cartilage to the first tracheal ring may obviate the need for total laryngectomy in selected cases.

Neurofibroma. This is a rare tumor arising from the Schwann cells. The tumor most commonly arises from the aryepiglottic fold. The incidence favors females 2:1.

Granular Cell Myoblastoma. These tumors are thought to be of neurogenic origin. They occur in any age group and preponderantly affect males. The lesion usually occurs at the posterior aspect of the true cords or arytenoids. The lesion is small, sessile, and gray. Hoarseness is often the only symptom. The mucosa may show pseudoepitheliomatous hyperplasia.

Treatment: Excision by direct laryngoscopy.

23 Adenoma. This tumor is rare. It arises from the mucous glands. The most common site is the false cord or ventricle.

Treatment: Excision perorally or by thyrotomy.

Chemodectoma. Chemodectomas arise from paraganglion tissue. They usually are seen in the false cord and aryepiglottic fold, and are smooth, cystic, and red. Biopsy may be associated with bleeding.

Treatment: Lateral pharyngotomy.

Lipoma. Lipoma is a rare, pedunculated or submucosal tumor which usually arises from the aryepiglottic fold, epiglottis, true cord, and pharyngeal wall.

Treatment:

1. Excision via laryngoscope for pedunculated lesion. 2. Lateral pharyngotomy for submucous tumor.

Hemangioma. Hemangioma in adults are more common than in children. They occur on vocal cords, subglottic regions, and pyriform sinus. Hemangioma in children is discussed under Congenital Anomalies.

Treatment: Excision is best handled by suspension laryngoscopy (for a small angioma) or by lateral pharyngotomy (for a large angioma).

Pseudoepithelial Hyperplasia. This is a benign epithelial change that may resemble carcinoma. It can be caused by:

1. Tuberculosis. 2. Syphilis. 3. Granular cell myoblastoma. 4. Blastomycosis. 5. Pachyderma laryngis. 6. Radiation. 7. Papillary keratosis (premalignant).

When a diagnosis of pseudoepithelial hyperplasia is made, further biopsy or studies may be necessary to rule out blastomycosis, granuloma cell myoblastoma, etc.

Cysts and Tumorlike Lesions of the Larynx

Retention Cyst. Retention cyst occur most often where mucous glands are abundant. The false cord, ventricle, epiglottis, aryepiglottic fold may be the sites.

24 Treatment:

1. Laryngoscopic removal. 2. Maruspialization.

Prolapse of the Ventricle. Ventricular prolapse is protrusion of ventricular mucosa between the true and false cords. It is frequently associated with chronic bronchitis, and the presenting symptom is hoarseness. A sessile pink mass arising between the false and true cord is seen.

Treatment: Laryngoscopic removal with a forceps.

Laryngocele: This is an air-filled dilation of the appendix of the ventricle. There are two types:

1. External laryngocele, the more common form in which the sac protrudes above the thyroid cartilage and the thyrohyoid membrane and presents as a mass in the neck. 2. Internal laryngocele, less common, in which the sac remains within the thyroid cartilage.

3. The combined type may be present.

Etiology: Unknown.

Symptoms:

1. External laryngocele presents as a swelling in the neck which increases in size with increased intralaryngeal pressure. 2. Internal laryngocele presents with hoarseness and dyspnea. 3. Indirect laryngoscopy may show a smooth dilation at the false cord level involving the false cord and aryepiglottic fold. 4. Diagnosis may be confirmed by a tomogram of the neck showing air within the sac.

Treatment:

1. Laryngoscopic decompression for small lesions. 2. Lateral external approach for larger lesions.

Contact Ulcer of the Larynx

Etiology:

Contact ulcers and granulomas appear to be caused by vocal abuse or nonlinguistic laryngeal trauma, such as repeated harsh coughing or persistent throat clearing. Allergic rhinosinusitis causing postnasal drip also may be a factor. Many patients have a hiatal hernia or peptic esophagitis, predisposing to reflux of gastric contents and acid into the pharynx, with resulting coughing, laryngospasm, and harsh throat clearing. Contact ulcers and

25 granulomas heal when the hiatal hernia, gastric reflux, and peptic esophagitis are treated adequately.

Pathology: The most common site is vocal process of the arytenoid.

Symptoms:

1. Hoarseness. 2. Pain on exertion. 3. Typical ulceration.

Treatment:

1. Absolute voice rest. 2. Vocal reeducation. 3. Avoidance of irritants. 4. Broad-spectrum antibiotics and steroids may be of help.

Vocal Nodules (Singer's Nodules)

This may be considered a localized traumatic laryngitis.

Etiology:

1. Vocal overuse: Screaming in children, harsh talking in adults, and faulty techniques in singers. 2. Predisposing factors: Ectomorphic and athletic body type, vociferous and aggressive personalities. 3. Precipitating factors: Allergy, thyroid and emotional imbalance, URI, sinusitis. 4. Aggravating factors: Cigarette smoking and alcohol.

Pathology:

There are two types:

1. Acute or fresh type (soft, reddish, vascular, edematous). 2. Chronic or mature type (hard, white, thickened, fibrosed).

Clinical Features:

1. Found more often in women, children (more often in boys), professional singers, lecturers, etc. 2. Causes hoarseness. 3. The most common site is at the junction of the anterior and middle third, usually bilateral (see Table 15-1). The middle part of the membranous vocal cord has the greatest amplitude of vibration, and hence is most likely to develop singer's nodule.

26 Treatment:

For children:

1. Parent counselling. 2. Psychotherapeutic rehabilitation. 3. Vocal reeducation. 4. Microlaryngoscopic laser excision in rare cases unresponsive to voice therapy.

Table 15-1. The Most Common Site of Benign Laryngeal Lesions

Contact ulcer Vocal process of arytenoid Uni- or bilateral Laryngeal polyp Junction of anterior and middle third Usually unilateral Vocal cord nodule Junction of anterior and middle third Bilateral Postintubation Vocal process of the arytenoid About 50% bilater.

For adults:

1. Voice rest. 2. Voice therapy. 3. Microlaryngoscopic excision or laser vaporization followed by voice therapy.

Intubation Granuloma

Etiology: Endotracheal intubation.

Age and sex: All adults. The incidence is higher in females (4:1) because the tube falls more to the posterior commissure, and because the mucosa is thinner.

Site: Invariably on the vocal process of the arytenoid.

Treatment:

1. Excision when pedunculated. 2. Attempts of removal during the sessile stage should be avoided as recurrence is likely. 3. Microlaryngoscopic laser excision appears to be more effective than surgical excision.

Chronic Nonspecific Disease of the Larynx

Pachyderma Laryngis

Pachyderma laryngis is a specific entity in which the posterior commissure and the posterior thrid of the true cords are the site of a localized hyperplastic and keratinized process. Histologically, acanthosis, parakeratosis, keratosis, and hyperkeratotic papilloma are noted. There is no dyskeratosis. It is not premalignant. Diagnosis is made by biopsy.

27 Treatment: Nonspecific.

Keratosis of the Larynx

This is a term used to denote a group of premalignant epithelial lesions in which an abnormality of growth and/or maturation has occurred.

Etiology:

1. Smoking, vocal abuse, chronic laryngitis, vitamin deficiencies. 2. Exact cause unknown.

Symptoms:

1. Hoarseness is the only symptom. 2. A raised reddish area of mucosal irregularity overlying a portion of one or both cords with chronic inflammation.

Treatment:

1. Cessation of smoking and other causative agents. 2. Direct laryngoscopy with excision. 3. Periodic examination.

Leukoplakia of the Larynx

This is a pathologic premalignant process characterized by a thick whittish layer of hyperkeratotic epithelial cells.

Etiology: Vocal abuse, excessive smoking and intake of alcohol, iritative environment.

Symptoms:

1. Hoarseness. 2. White patches on vocal cords.

Treatment:

1. Laryngoscopic excision. 2. Removal of causative factors. 3. Periodic examination.

28 Arthritis of the Cricoarytenoid Joint

Etiology:

1. Rheumatoid arthritis is by far the most common cause (about 25% of cases of rheumatoid arthritis). 2. Gout, collagen diseases (lupus erythematosus). 3. Gonorrhoea, tuberculosis, syphilis, rare. 4. Trauma.

Symptoms:

1. Lump in throat. 2. Throat pain aggravated by swallowing or speaking. 3. Referred ear pain. 4. Hoarseness, stridor, and dyspnea. 5. Striking, bright red swelling over the arytenoid. 6. Palpation of the arytenoid produces severe pain. 7. Vocal cord may be fixed in the paramedian or intermediate position. Direct laryngoscopy and palpation of the arytenoids is necessary to differentiate fixation from paralysis. 8. Other signs of rheumatoid arthritis (sedimentation rate, C-reactive protein, and gamma globulin, abnormal; positive test for rheumatoid factor).

Treatment:

1. Control systemic rheumatoid arthritis. 2. Salicylates. 3. Steroids. 4. Tracheotomy. 5. Arytenoidectomy or arytenoidopexy for midline fixation of both vocal cords. Unilateral fixation rarely requires therapy. 6. Teflon injection.

Acquired Stenosis of the Larynx

Injury to the larynx leading to acquired stenosis can involve the supraglottis, glottis, or subglottis, or any combination of these.

Clinical features and evaluation:

1. Careful history taking. 2. Thorough physical examination of ENT areas with special attention to the neck, larynx, and pharynx. 3. Radiologic examination should include x-rays of the chest and lateral neck, and laminogram of the larynx. Xeroradiography and/or contrast laryngography may be helpful in delineating abnormalities. A CT scan has been found to be of great value in evaluation of laryngeal trauma.

29 4. Endoscopy.

a. Fiberoptic flexible nasopharyngolaryngoscope (Machida or Olympus). This is a very useful atraumatic diagnostic tool for evaluation of laryngeal trauma. This also can be used to evaluate the subglottic region via the tracheotomy stoma and may eliminate the need for direct laryngoscopy in some cases. b. Rigid telescope with right-angle lens (excellent tool for photographic documentation). c. Direct laryngoscopy. d. Esophagoscopy. e. Tracheoscopy. f. Bronchoscopy.

Supraglottic Stenosis

Etiology:

1. External crushing trauma in the region of the hyoid bone inflicted during an automobile accident. 2. Penetrating wound, caustic ingestion, severe infection.

Clinical features:

1. In supraglottic injuries, the blow often leads to fractures of the thyroid ala transversely with detachment of the epiglottis and false cords from the anterior commissure. 2. The most common injury seen is rupture of the thyroepiglottic ligament with superior retraction of the epiglottis and herniation of the soft tissues of the preepiglottic space into the laryngeal lumen. 3. There often is an associated tear in the posterior pharyngeal wall. The arytenoid cartilages may be dislocated. The epiglottis is easily seen on tongue depression in these cases. This is a useful clinical sign. 4. Direct laryngoscopy reveals that the false cords are splayed apart and necrotic granulation tissue is present between the true and false cords.

Treatment:

1. Tracheotomy may be a lifesaving measure. Intubation prior to tracheotomy should be avoided. 2. The transhyoid or thyrotomy approach should be used for repair of lacerations and for replacing various structures to their normal position. Epiglottidectomy and arytenoidectomy may be necessary.

30 Glottic Stenosis

Classification: Glottic stenosis may be classified into three varieties:

1. Anterior stenosis (web):

a. With laryngeal function. b. With bilateral paralysis.

2. Posterior stenosis.

3. Complete stenosis.

a. With laryngeal function. b. With bilateral laryngeal paralysis.

Anterior Glottic Stenosis

Two types:

1. Anterior web results from traumatic endoscopy, lye burns, infections, or foreign body. 2. More extensive (thick) stenosis usually results from external trauma.

Clinical features:

1. Symptoms from anterior webs may be minimal. 2. Hoarseness. 3. Varying degrees of respiratory distress.

Treatment:

For thin webs:

1. Endoscopic section followed by dilatations.

For thick stenosis:

a. When vocal cords are not paralyzed:

1) Endoscopic section with insertion of a keel without thyrotomy as described by Dedo.

2) External thyrotomy approach with insertion of a keel.

b. When bilateral paralysis complicates the glottic stenosis: External thyrotomy approach with arytenoidectomy with lateralization of the vocal cord and insertion of a conforming silicone stent (instead of a keel).

31 Posterior Glottic Stenosis

Etiology:

1. External trauma. 2. Internal trauma. 3. Infection (tuberculosis, diphtheria).

Clinical features:

1. Diagnosis is made by indirect, fiberoptic, or direct laryngoscopy. 2. Dyspnea on exertion and hoarseness.

Treatment:

1. Resection of posterior web via thyrotomy approach. 2. Montgomery recommends use of a superiorly based mucous membrane flap from the interarytenoid space.

Complete Glottic Stenosis

Etiology: External laryngeal trauma.

Treatment:

1. Anterior midline vertical thyrotomy approach with incision of stenotic area in the midline. 2. Use of local mucosal flap, buccal or nasal septal mucosa grafts, or split-thickness skin grafts. 3. Insertion of a conforming intralaryngeal stent. 4. The stent is left in position for 4-8 weeks. 5. When bilateral vocal cord paralysis accompanies complete glottic paralysis, arytenoidectomy is necessary.

Subglottic Stenosis

Etiology:

1. Long-term endotracheal intubation (most frequent). The incidence reported by different authors varies between 0.9-3.0%. This problem occurs most frequently in children, since in them the subglottis is the narrowest part of the upper airway. Consequently, pressure from an endotracheal tube inflicts the most damage to this area. 2. External trauma (penetrating wound). 3. Internal trauma (high tracheotomy, traumatic endoscopy, foreign body). 4. Neoplasm (chondroma, fibroma, and carcinoma are most common in this area). 5. Radiation. 6. Severe infection. 7. Congenital stenosis.

32 Clinical features:

1. Dyspnea on exertion. 2. Wheezing is common and is often misinterpreted as asthma or a chronic tracheobronchial infection. 3. Nonproductive cough and voice change. 4. The diagnosis can be made by indirect laryngoscopy. However, it is very difficult to determine the exact level of the stenosis with the laryngeal mirror examination. A lateral neck x-ray resolves this problem by indicating more exactly the size of the lesion. The lesion is even more accurately outlined in a laminagram, laryngogram, or CT scan. The inferior extent may be evaluated by a flexible fiberoptic endoscope passed retrogradely via a tracheotomy stoma.

Treatment:

1. Dilatation may be helpful, but also may be harmful since it may denude the mucosa thereby worsening stenosis. 2. Local steroid injection may be of benefit in some cases. 3. A low tracheotomy may be used. 4. Rethi's procedure: Rethi described a procedure in which the anterior and posterior rings of the cricoid are splin in a sagittal plane. This enlarges the diameter of the subglottic lumen without disturbing the esophageal mucosa. A Montgomery's stent is inserted with or without a mucosal graft to ensure maintenance of anterior and posterior diastasis of the cartilage fragments. Although Rethi did not originally describe keel insertion to prevent anterior commissure webbing, this approach is currently considered preferable. The keel is inserted at the time the internal stent is removed through a laryngofissure. The keel is then removed 2 weeks later. 5. Hyoid arch transposition: In 1975, Druck et al described a method of treatment for subglottic stenosis in which the anterior arch of the cricoid is removed, and an autogenous bone graft from the midportion of the hyoid is interposed between the cut edges of the cricoid, thereby externally widening the subglottic diameter. 6. Cricoid excision with thyrotracheal anastomosis: Conley introduced the concept of segmental resection of the stenotic subglottis with end-to-end anastomosis, and it has subsequently been reported on by several authors (Gerwat and Bryce; Carcassone et al; Pearson et al). 7. Laryngotracheoplasty: In 1974, Evans and Todd reported use of a surgical approach for relief of subglottic stenosis in children. In this procedure, the laryngofissure is modified in a "stepped-off" fashion, producing cartilaginous interdigitations of the cricoid and upper tracheal rings on each side. These interdigitations are distracted, and the open position is maintained by suturing the cartilage externally and stenting internally with rolled Silastic sheeting. The internal stent is then removed after 6 weeks by the endoscopic approach. Good results have been reported with use of this method. 8. Anterior cartilage splitting with autogenous costal cartilage graft: Doig et al first described the use of anterior cricoid cartilage splitting with an autogenous costal cartilage graft inserted to widen the cricoid ring. A similar procedure has been advocated by Fearon and Cotton for treatment of subglottic stenosis in pediatric patients. Excellent results have been reported.

33 Congenital Anomalies of the Larynx

Congenital Web

A congenital web develops as a band which extends over part (web) or all (atresia) of the glottis. However, the anterior two-thirds of the glottis is the most susceptible site.

Symptoms:

1. Depend on degree of glottic closure. 2. Atresia present as severe dyspnea at birth. Death may follow if not promptly recognized and treated. 3. Small web may be asymptomatic. 4. Mainly weak or hoarse cry and cough.

Treatment:

1. Immediate insertion of a bronchoscope or a tracheostomy tube for atresia. 2. Thyrotomy and insertion of a McKnaught's tantalum plate between the vocal folds.

Congenital Laryngeal Cyst

This cyst occurs most commonly in the supraglottic area (lateral wall of supraglottis or on the epiglottis) or associated with a laryngocele, producing inspiratory stridor and weak cry. Diagnosis is made by direct laryngoscopy.

Treatment:

1. Emergency treatment by aspiration. 2. Endoscopic excision later.

Congenital Subglottic Stenosis

The subglottic region 2-3 mm below the true cord is the site of predilection.

Symptoms:

1. Severe barking stridor. 2. Expiratory stridor if subglottic.

Treatment:

1. 40-50% need tracheotomy. 2. Dilatation.

34 Vocal Cord Paralysis

Etiology:

1. Trauma at birth (unilateral). 2. Platybasia (bilateral). 3. Arnold-Chiari syndrome (bilateral). 4. Left vocal cord paralysis may result from stretching of the left recurrent nerve due to a congenital cardiovascular lesion.

Symptoms:

Unilateral: Weak cry. Bilateral: Crowing inspiration, severe stridor.

Treatment:

Unilateral: No treatment. Bilateral: (1) Tracheotomy; (2) Arytenoidectomy or arytenoidopexy best delayed until age5or6.

Subglottic Hemangioma

Subglottic hemangioma is a rare anomaly of early infancy which may be associated with a skin hemangioma (50% of cases). The anterior subglottic area is the most susceptible site.

Symptoms:

1. Inspiratory stridor is noted at birth or soon thereafter. 2. There may be a history of repeated episodes of croup. 3. Hoarseness is not a common symptom. 4. Direct laryngoscopy reveals a pink to blue, easily compressible, subglottic tumor. 5. A biopsy is never done, since the ensuing hemorrhage may be fatal. 6. The tumor can be seen on a lateral neck x-ray.

Treatment:

1. Tracheotomy for respiratory obstruction. 2. Systemic administration of steroids (Cohen): A course of prednisone (20 mg) daily for 1 month and repeated 1-2 times as indicated. This may be the least hazardous therapy. 3. Intralesional injection of steroid. 4. Use of the carbon dioxide laser excision appears to be a safe, effective treatment for subglottic capillary hemangiomas and recommended by Healy et al. It is not used for cavernous-type lesions. Intense humidification is necessary in the immediate postoperative period to prevent crust formation. 5. Radiation therapy: Because of the possibility of injury to developing laryngeal cartilage and the risk of thyroid carcinoma exists, radiation therapy is not recommended.

35 6. Surgical excision via a midline tracheal incision and an intraluminal stent.

Laryngomalacia

This is the most common laryngeal abnormality of the newborn and is due to unusual flaccidity of the laryngeal tissues, especially the epiglottis.

Symptoms:

1. Inspiratory stridor and noisy respiration noted soon after birth, usually worse with the infants on their backs compared with the infants on their stomachs. 2. Diagnosis requires direct laryngoscopy which reveals a flaccid, curled epiglottis which is drawn over the glottis on inspiration. 3. The vocalcords are normal in appearance and motility. 4. Rule out lower respiratory tract anomalies by bronchoscopy.

Treatment:

1. Observation (stridor usually disappears by 12-16 months of age). 2. Tracheotomy in rare cases.

Cri-du-Chat Syndrome

Recently a new nosologic entity called the cri-du-chat syndrome was described (Ward et al) in which the larynx has the same appearance as that seen in laryngeal chondromalacia. The cri-du-chat syndrome is caused by partial deletion of a number 5, group B chromosome and is characterized by a weak, wailing cry, like that of a kitten. Other accompanying features of the syndrome include severe mental retardation, a rounded facies, a beaklike profile, microcephaly, hypotonia, hypertelorism, antimongoloid palpebral fissures, epicanthal folds, strabismus, and a variety of visceral abnormalities.

Laryngeal Clefts

Laryngeal clefts are very rare. Irregular and incomplete fusion of the laryngotracheal septum results in a tracheoesophageal fistula or cleft of the larynx. These anomalies are manifest very soon after birth.

Symptoms:

1. Cyanosis with feeding. 2. Stridor. 3. Abnormal cry. 4. Pneumonia. 5. Usually fatal unless diagnosed early and corrected early. 6. Diagnosis made by direct laryngoscopy.

36 Laryngeal Atresia

Laryngeal atresia results from a failure of the developing larynx to recanalize after the normal epithelial fusion that takes place toward the end of the third month of gestation. Atresia may be at the supraglottic, glottic, or subglottic levels either separately or combined.

Clinical features:

1. Aphonia if atresia is complete. 2. Hoarse stridorous if atresia is incomplete.

Treatment:

1. Immediate tracheotomy. 2. When the laryngeal skeleton is preserved: Partial resection of the atretic portion in the transverse plane with reanastomosis of the distal portion of the laryngotracheal tube to the proximal part. 3. When the entire laryngeal lumen is filled with scar: A hollowed groove for the future respiratory tube is created, lined with a free skin graft, and later implanted with cartilage.

Congenital Supraglottic Webs

If they are relatively thin and membranous, supraglottic webs may be treated by direct incision of the web through the laryngoscope. Thicker webs may require subsequent dilatation to maintain an adequate lumen.

Congenital Glottic Stenosis (Webs)

Glottic stenosis occurs in three different forms (Holinger): (1) A thin, transparent, membranous sheet covering the superior aspect of the true vocal cords and the anterior part of the intervening glottis; (2) a web of variable thickness lying between portions of the membranous cords; and (3) fusion of the anterior half of the true vocal cords.

Treatment:

For thin web:

1. Endoscopic section followed by dilatations.

For thick web:

1. Endoscopic section with insertion of a tantalum or silicone keel. Tracheotomy required. 2. External thyrotomy approach with insertion of silicone keel. The keel left for 2 weeks.

37 Acute Laryngeal Trauma

Blunt trauma to the neck is being seen with increasing frequency. Severe laryngeal injury may occur without open neck injuries. The undiagnosed laryngeal trauma case may succumb early from laryngeal obstruction or develop late laryngeal stenosis that requires the permanent wearing of a tracheotomy tube.

Three poor prognostic features in acute blunt laryngeal injuries include: early airway obstruction requiring tracheotomy, the presence of bare cartilage in the laryngeal lumen, and fracture and collapse of the cricoid.

Clinical manifestations:

In any patient who has sustained a possible laryngeal injury, the following symptoms are indicative of some derangement of laryngeal structure:

1. Increasing airway obstruction with dyspnea and stridor. 2. Dysphonia or aphonia. 3. Cough. 4. Hemoptysis. 5. Neck pain. 6. Dysphagia and odynophagia.

Distinctive clinical signs indicative of laryngeal injuries are:

1. Deformities of the neck including alteration in contour and swelling. 2. Subcutaneous emphysema. 3. Laryngeal tenderness. 4. Crepitus over the laryngeal framework.

Diagnosis:

1. Indirect and direct laryngoscopy: Direct laryngoscopy may precipitate airway obstruction in a patient with an acute laryngeal injury. In cases not requiring tracheotomy, indirect mirror laryngoscopy or flexible fiberoptic laryngoscopy gives a comprehensive and undisturbed view of the larynx. 2. Roentgenograms of the neck and chest must be taken to detect laryngeal fractures, tracheal injuries, and pneumothorax. 3. The CT scan is an excellent method of diagnosing hyoid fractures, fracture dislocation of thyroid and cricoid cartilages, and distortion of laryngeal structures.

Treatment:

1. Conservative management is recommended when blunt trauma has resulted in soft tissue injuries, such as small lacerations, ecchymoses, or submucosal hematomas without evidence of laryngeal fracture or a compromised airway. Conservative management includes voice rest, humidification, bed rest, and systemic steroids.

38 2. If immediate repair of the larynx cannot be done for any reason, it may be helpful to administer steroids, so that granulation tissue and collagen deposition would be reduced, thereby facilitating an anatomic repair.

3. For establishment of an airway tracheotomy is the preferred means of management in these patients (avoid high tracheotomy). Premature intubation can obscure important diagnostic considerations as well as precipitate life-threatening airway obstruction.

4. Cricothyrotomy may be indicated in a dire emergency. In such cases, remove the tracheotomy as soon as possible and convert it to a standard tracheotomy.

5. Many of these patients have multiple injuries; yet suspicion and recognition of the acute laryngeal injury is imperative.

6. Surgical exploration is indicated in any neck injury with symptoms of stridor, voice change, cartilage disruption, and cervical emphysema.

7. Exploration of laryngeal structure is best performed through a horizontal incision to minimize scarring of the anterior neck.

8. Tears of the pyriform sinuses, hypopharynx, posterior larynx, thyroarytenoid ligament and muscle are repaired.

9. When repairing laryngeal injuries all mucosa must be sutured carefully. Local flaps or free mucosal grafts taken from the epiglottis or buccal mucosa should be used to close defects. All cartilaginous and submucosal tissues must be covered with epithelium.

10. If an arytenoid cartilage is completely avulsed and displaced, it is better to remove it than attempt to reposition it. Partial arytenoid disruption can be treated with repositioning and mucosal repair.

11. Laryngeal cartilage fractures, like any other fractures, must be reduced and immobilized. Repair should be done within 7-10 days of the time of injury.

12. Splint a laryngeal fracture by means of a mold or stent in the laryngeal lumen. A rubber finger-cot, filled with Ivalon sponge may be used.

13. The stent is usually inserted through a thyrotomy or infrahyoid laryngotomy and is fixed above and below by stainless steel sutures passes through the skin.

14. The stent is fixed in a position so that the upper end is at the level of the aryepiglottic folds and the lower end is just above the tracheotomy site. It should be left for 4-8 weeks.

39 Foreign Bodies in the Larynx and Tracheobronchial Tree

1. Choking on foods causes 2500-3000 deaths per year in the USA. It is the sixth most common cause of accidental death. Fifty-five percent of aspirated foreign bodies involve the respiratory tract in children 6 months to 4 years of age. The accident is neither observed nor suspected in over one-third of these cases.

2. All techniques which are used for aiding the obstructed patient in an emergency such as pounding on the back, Heimlich maneuvers, and finger probing of the throat are dangerous and should be discouraged unless the airway obstruction is unrelieved by the patient's own reflexes. These techniques may result in further impaction and the possibility of a total obstruction not present before these attempts.

3. In the series of Cohen et al, nuts were the most common type of foreign body aspirated (55), followed by food particles (20%), and metallic objects (16.7%). Forty-three percent were found in the left bronchial tree (contrary to the common belief based on anatomic details), 38% in the right bronchial tree, and 4% in the larynx.

4. General anesthesia is recommended. Oxygen standby without any anesthesia may have to be used in cases where the airway obstruction is severe and the airway cannot be adequately controlled.

5. The most common postoperative problem is subglottic laryngeal edema, treated with humidification and systemic steroids. Bronchitis, pneumonia (impaction with long-standing foreign bodies), and laryngotracheobronchitis may be seen. Complications of foreign bodies include bronchial suppuration, bronchial ulceration, granulation tissue, bronchial stenosis, peribronchial and peritracheal lymphadenopathy with compression of bronchi, pneumonitis, atelectasis, obstructive emphysema, pneumomediastinum, and pneumothorax.

6. Encapsulated dry vegetable substances can swell in the presence of moisture and may have to be broken into smaller pieces to avoid total obstruction of the trachea during removal.

7. A serious intraoperative complication can result from the removal of a large obstructive foreign body from the bronchus and having it get stuck at the level of the larynx. Attempts should be made to remove it from the glottis but if this is not possible, the foreign object should be pushed back down into one of the bronchi so that ventilation can proceed with the unobstructed lung.

8. Anesthesia methods: Preanesthesia medications - narcotics and sedatives - are contraindicated because they may depress respirations from anesthesia. The apneic relaxant technique allows sufficient time for the atraumatic manipulations of the bronchoscope. This consists of a light plane of anesthesia accompanied by a muscle relaxant.

9. Intravenous dexamethasone phosphate (4-8 mg) is given before endoscopy to minimize subglottic edema.

40 Paralysis of the Larynx

1. The larynx is supplied by two branches of vagus nerve: superior laryngeal and inferior (recurrent) laryngeal nerves.

The superior laryngeal nerve divides extralaryngeally into: (a) the internal branch which supplies sensory innervation to the laryngeal cavity above the glottis, and (b) the external branch (motor) which supplies the cricothyroid muscle.

The recurrent or inferior laryngeal nerve supplies motor innervation to all the intrinsic laryngeal muscles of the same side except for the cricothyroid and to the interarytenoid muscle of both bodies. It also supplies sensory innervation to those portions of the larynx below the glottis.

2. Paralysis of the laryngeal muscles originates in one of two areas: the central nervous system or the peripheral motor nerves. In most cases (90%) laryngeal paralysis is the result of peripheral nerve involvement. Arising from the ambiguus nucleus in the midbrain, motor impulses to the intrinsic laryngeal muscles travel via the vagus nerve into the chest, where they enter the recurrent laryngeal nerve. On its passage back to the larynx the right recurrent laryngeal nerve crosses the right subclavian artery, while the left recurrent laryngeal nerve winds awounds the arch of the aorta in close relation to the heart. The ascent of the recurrent laryngeal nerve occurs in a groove between the trachea and the esophagus in close relation to the mediastinal lymph nodes, thyroid gland, and esophagus. Thus a swelling of any of these structures may cause pressure on one of the recurrent laryngeal nerves and obstruct muscles on the involved side. Depending upon the nerve fibers involved and the muscles they supply, many different types of paralysis may occur.

3. Paralyzed vocal cords are best described by their position - median, paramedian, intermediate, extreme abduction (lateral). In the median position, the paralyzed cord remains in the midline. This is a frequent position of a paralyzed vocal cord since the abductor muscles are weaker and more vulnerable than the adductor fibers. The intermediate position, often called cadaveric, is midway between the midline and position of complete abduction. The paramedian is between the median and intermediate.

4. Regardless of the type of paralysis it is hard to predict the permanent position of the vocal cord because of:

a. Continued function of remaining musclers. b. Muscle fibrosis. c. Tone of the autonomic system. d. Tension of the conus elasticus.

5. Unilateral midline paralysis is the most frequent; the left more than the right. The paralyzed vocal cord usually lies lower than the normal cord.

41 6. Diagnostic evaluation:

a. Careful history and physical examination.

b. Inspection. Indirect mirror examination of the larynx is the time-honored standard for evaluating the larynx. Flexible fiberoptic scopes passed through the nose and nasopharynx, or a rigid lens system introduced through the oral cavity, provide a better view of laryngeal movement and allow prolonged study of the larynx during phonation. These laryngoscopes are adaptable to high-speed cinematography or the TV camera, giving permanent records of the patient's laryngeal function.

Laryngostroboscopy augments the routine indirect mirror examination in studying vocal cord mobility. In this technique a contact microphone is placed on the neck of the patient to pick up his voice and transmit it to an analyzer that determines the fundamental vocal frequency. The fundamental frequency is transmitted electronically to a xenon lamp which flashes an intermittent beam of light at the same frequency. The light is then reflected - using a standard head mirror - to the laryngeal mirror and then to the larynx. The strobe light gives the laryngologist the optical illusion that the vocal cords are moving slowly or not at all. This allows the vocal cords to be studied throughout their vibratory cycle. It is an expensive device of interest primarily to the researcher of vocal function. It does not yet replace the standard indirect laryngoscopy for the practicing otolaryngologist.

c. Electromyography: With the patient awake under topical anesthesia, EMG can be done with hook needle electrodes through an external approach. This technique gives a precise indication of the function of the intrinsic muscles of the larynx, but requires experience and a special skill in the placement of these electrodes. Hirano et al claim that it can be done without affecting normal speech and articulation and that muscle activity can be recorded during normal speech. Although this has a great deal to offer in exactly delineating the extent of laryngeal nerve paralysis, it is still a research tool in most institutions at the present time.

d. Laboratory studies:

1) CBC, ESR, urinalysis. 2) Chest x-ray, PA and lateral. 3) Skull series, particularly base view to rule out erosion of jugular foramen. 4) Cervical spine films. 5) Barium swallow. 6) Thyroid scan. 7) VDRL, FTA. 8) Glucose tolerance test. 9) Lumbar puncture.

e. Endoscopy: Endoscopy should be done as the last step in evaluating vocal cord paralysis. This should include nasopharyngeal examination to rule out neoplasm, direct laryngoscopy to palpate the arytenoid to differentiate vocal cord paralysis from fixation of the cricoarytenoid joint, and bronchoscopy and esophagoscopy to rule out a mass lesion or occult neoplasm even if routine x-ray is normal.

42 f. Radiological evaluation: Laryngeal tomograms and contrast laryngograms can be of value in the detection and evaluation of vocal cord paralysis. In recurrent laryngeal nerve paralysis, four distinctive x-ray findings have been reported: (1) The vocal cord takes a triangular shape. (2) The laryngeal ventricle is dilated. (3) The cross-sectional area of the vocal cord is diminished. (4) The normal subglottic shoulder is replaced by a straight line. In addition, a loss of abduction can be seen on inspiration. A CT scan of the larynx also will be of help in evaluation of laryngeal paralysis.

Unilateral Paralysis

Etiology: Unilateral paralysis of the vagus or recurrent laryngeal nerve can be the result of one of the following:

1. Tumor in the thyroid gland, mediastinum, or esophagus. 2. Surgical trauma. The most commoncause is thyroidectomy. 3. Pressure on the left recurrent laryngeal nerve by a hypertrophied heart or an aortic aneurysm. 4. Toxic neuritis following influenza, or alcohol, lead, or arsenic poisoning. 5. Rarely by a central lesion. 6. Unknown cause (about 20%).

Finding:

1. Involvement of the nerve may be partial, with weakness and decreased motility of the ipsilateral cord, or may be total with a resulting unilateral paralysis.

2. The paralyzed vocal cord usually is fixed in the paramedian position (incomplete paralysis).

3. Involvement of the vagus nerve may lead to fixation in an intermediate or lateral position (complete paralysis). Depending on the cause, the paralysis may be either temporary or permanent.

Symptoms: Hoarseness is usually the only symptom of unilateral laryngeal paralysis. Even this symptom often gradually disappears as the healthy cord increases its excursion beyond the median line. Functional apposition of the voice may persist for a somewhat longer period. The feebleness of the cough mechanism parallels the degree of hoarseness.

Treatment:

Nonsurgical:

1. Voice therapy.

Surgical:

1. Medialization technique: One of the early attempts to correct the breathiness of unilateral vocal cord paralysis by the technique of medialization of the paralyzed vocal cord

43 was described by Meurman who placed a piece of autogenous costal cartilage between the thyroid cartilage and the inner perichondrium just lateral to the paralyzed cord through the midline thyrotomy approach. A wedge of thyroid cartilage has been used Copheim and others.

2. Arytenoidopexy: The abducted paralyzed cord can be brought to the midline and held there by direct suture (reverse King's procedure) or by pin fixation (Montgomery). The reverse King's procedure is routinely done during supraglottic laryngectomy when the cord is paretic or the arytenoid is sacrificed. Montgomery's arytenoidopexy is used in laryngeal reconstruction following trauma to restore glottic competence.

3. Intracordal injection of the vocal cord was first performed by Brunings - in 1911. He used paraffin for injection but because it resulted in paraffin granulomas the technique has been discontinued.

Arnold using Teflon mixed with glycerin, revived injection of the vocal cord for treatment of paralysis. Largely through his work and that of Lewy, Teflon injection has become the mainstay of treatment for hoarseness, aspiration, and loss of cough seen in vocal cord paralysis.

Gelfoam paste may be injected initially to judge whether or not vocal augmentation will be effective.

4. Nerve-muscle transposition: The most recent procedure suggested for treatment of the intermediate vocal cord paralysis was introduced in 1977 by Tucker. He reported his preliminary experience with the nerve-muscle technique to restore adduction of the unilaterally paralyzed vocal cord. He states that there are two major advantages to his technique: (a) avoidance of the need to section and/or anastomose nerves, and (b) selective reinnervation of only those necessary muscle groups. To this date, the nerve-muscle pedicle technique has been applied in nine patients with unilateral vocal cord paralysis. This procedure is reserved for patients with unilateral vocal cord paralysis showing evidence of involvement of the superior and recurrent laryngeal nerves, a posterior glottic defect greater than 3-4 mm, and a bowed vocal cord. In addition, it is recommended that 6 months be allowed to lapse to permit possible spontaneous reinnervation of compensation to occur before performing this surgical procedure. Through a horizontal incision, the main loop of the ansa hypoglossi over the jugular vein is identified and traced distally until the branch to the anterior belly of the omohyoid muscle is seen. The nerve-muscle pedicle is designed by mobilizing the nerve branch with its blood supply. The nerve will travel a few millimeters between the muscle bundles before branching. The portion of muscle that should be excised lies just past the actual point of nerve entry to preserve the motor end plates. Sutures are then placed around a 3 mm2 block of muscle adjacent to the nerve. The block is then cut from the omohyoid muscle. The technique for unilateral intermediate vocal cord paralysis differs at this point in that a window of thyroid cartilage is carefully removed, maintaining the inner perichondrial layer. This is incised and reflected, exposing the outermost fibers of the lateral thyroarytenoid muscle. The previously prepared nerve-muscle pedicle is sutured into place using the stay sutures. The outer perichondrium is then sutured back into place and the wound is closed.

44 Bilateral Abductor Paralysis

Bilateral abductor paralysis is the most common form of bilateral motor paralysis, and is of great clinical importance.

Etiology: In almost all instances it is by extensive thyroid surgery, with injury of both recurrent laryngeal nerves.

Findings: Bilateral abductor paralysis of the vocal cords is manifested by a paralysis of both vocal cords near the median line.

Symptoms:

1. Destruction of both recurrent laryngeal nerves or injury of these nerves is usually followed by a history of transient hoarseness. 2. Weakness of voice is usually prolonged. 3. Cough mechanism is less forceful. 4. As the vocal cords approach the median line, respiratory embarrassment may become increasingly severe requiring an immediate establishment of adequate airway.

Treatment:

1. A tracheotomy should be performed for respiratory difficulty. 2. The long-term management of this condition requires lateralization of one of the paralyzed vocal cords to an appropriate position so that the airway will be adequate for removal of the tracheotomy and the voice will not be weakened excessively.A5mmglottic chink provides an adequate airway, but may result in a weak voice. Four millimeters seems to be ideal if the treated paralyzed cord is at a lower level than the nonlateralized cord. There are three major techniques:

Endolaryngeal arytenoidectomy: In 1948 Thornell first described the oral approach to arytenoidectomy for lateralization of one or both vocal cords. A contraindication to this procedure is severe cardiopulmonary disease where adequate respiratory function requires a normal glottic airway of a tracheotomy tube. This procedure has been regarded as being

technically difficult. However, use of the surgical microscope and CO2 laser has made this procedure easier today.

Extralaryngeal arytenoidectomy:

a. Posterior approach: King first described an extralaryngeal approach to improve respiratory obstruction and to maintain the voice. Today, the Woodman's procedure, or a modification thereof, is the most frequently employed surgical approach for the treatment of respiratory obstruction due to bilateral vocal cord paralysis.

Through the external approach, the arytenoid is exposed. The body of the arytenoid is cut from the vocal process and removed. The suture is then tied around the inferior cornu of the thyroid cartilage while the surgeon, using a laryngoscope, directs the securing of the suture to allow lateralization of the vocal cord 4-5 mm and a downward positioning of 1-2

45 mm below the opposite cord level. A 5 mm posterior glottic chink is needed for an adequate airway in an adult, but witha5mmchink the voice is poor. Therefore it is suggested that the glottic chink be made 4 mm, but to place one vocal cord lower than the other. The success rate of decannulation is 75-95%.

b. Thyrotomy approach: This is the procedure of choice of many laryngologists for bilateral abductor vocal cord paralysis. It offers direct microsurgical visualization and exact placement of the vocal cord.

3. Nerve-muscle transposition: The technique of nerve-muscle pedicle transposition was described by Tucker. The advantages stated by Tucker are as follows:

a. It restores an adequate airway without further loss of voice. b. There is a return of function within 6-12 weeks. c. There is selective reinnervation of abductor muscles only that avoids crossed or inappropriate return of function. d. This procedure does not interfere with potential spontaneous reinnervation. e. This is technically less difficult than nerve anastomosis. The procedure is based on the assumption that the strap muscles are accessory muscles of respiration and contract during deep inspiration.

By transporting a nerve-muscle pedicle into the posterior cricoarytenoid muscle, one would expect contraction of this muscle and resultant abduction of the vocal cords during deep inspiration.

The indication for this operation is bilateral vocal cord paralysis with airway obstruction. Contraindications to this procedure are preexisting traumatic or neurologic loss of the branch of the ansa hypoglossi to the anterior belly of the omohyoid muscles, and fixation of the cricoarytenoid joints.

It is preferable to employ the reinnervation technique first for voice rehabilitation and if this fails, to use Teflon injection to supplement the results, especially in patients who rely on their voice for their livelihood.

Superior Laryngeal Nerve Paralysis

Etiology: Usually secondary to thyroidectomy or supraglottic laryngectomy.

Symptoms:

1. Lowered voice. 2. Posterior commissure deviates to the paralyzed side. 3. Paralyzed side has a vocal cord that is bowed, flabby, and lower. Guttman's test: Frontal pressure on the thyroid cartilage in the normal subject lowers the voice while lateral pressure raises his voice. In paralysis of the cricothyroid muscle, the opposite is true.

46 Treatment:

1. As a rule no therapy is necessary. 2. Vocal therapy. 3. A surgical procedure to narrow the cricothyroid space may be of benefit if symptoms are severe. Arnold described suturing the thyroid to the cricoid cartilage to elevate the cartilage during phonation.

Dysphonia

Dysplastic Dysphonia

Dysplastic dysphonia refers to chronic hoarseness due to structural malformation of the larynx (i.e. asymmetry of larynx, congenital webbing, vocal cord sulcus).

Habitual Dysphonia

1. Vocal nodules and polyps: Unilateral polyps cause different vibratory patterns of the two vocal cords leading to diplophonia. Polypoid degeneration of the entire cord is known as Reinke's edema. Speech therapy and surgical ablation (CO2 laser is especially useful here) are the modalities of treatment.

2. Chronic hypertrophic laryngitis is the end result of chronic laryngeal irritation secondary to vocal abuse, smoking, excessive alcohol, allergies, or nasal obstruction.

3. Dysphonia plicae ventricularis is faulty participation of the false cord in phonation. This disorder can be the end stage of chronic hyperkinetic dysphonia from continuous vocal abuse and also can be seen in some cases of laryngeal paralysis and CNS disorders.

Psychogenic Dysphonia of Emotional Origin

1. Hypokinetic and hyperkinetic psychogenic dysphonia. 2. Spastic dysphonia.

Endocrine Dysphonia

1. Gonadic disorders: Eunuchoid voice, laryngopathia gravidarum. 2. Thyroid and parathyroid disorders: Cretinism, myxedema, hyperthyroidism, calcium imbalances affecting speech musculature. 3. Adrenal disorders: Addison's disease leads to progressive aphonia secondary to muscular weakness. Adrenocortical hyperfunction leads to vocal virilization, particularly in women. 4. Pituitary disorders: Acromegaly leads to vocal virilization. Pituitary hypogenitalism results in the eunuchoid voice of dwarfism.

47 Paralytic Dysphonia: See Laryngeal Paralysis

Dysarthric Dysphonia of Central Origin

This may result from cerebral palsy, parkinsonism, chorea, multiple sclerosis, cerebellar disease, or bulbar paralysis.

Myopathic Dysphonia from Muscular Disease

Sternothyroid muscle paralysis secondary to injury of the ansa hypoglossi, and myasthenia gravis pseudoparalytica can result in myopathic dysphonia.

Neurovegetative Dysphonia from Autonomic Imbalance

1. Vasomotor monocorditis: Reddening, and edema of one vocal cord. Believed to be of vasomotor origin. It must be distinguished from laryngeal tuberculosis, syphilis, and early vocal cord cancer.

2. Contact ulcers: Associated with granuloma on the other vocal cord. Seen in singers and in "type A" personalities.

Traumatic Dysphonia After Laryngeal Injury

Hematomas, joint articulation injuries, and lesions of the extrinsic laryngeal muscles are the cause of traumatic dysphonia.

Spastic Dysphonia

1. Spastic dysphonia is a discrete vocal disorder characterized by strained, choked vocal attacks (laryngeal stuttering) and is associated with increased tension of the entire phonatory system. The voice characteristics in spastic dysphonia include glottic stammering, hoarseness, monopitch voice, and reduced volume. The secondary characteristics associated with this disorder include facial and neck grimacing, fatigue of chest musculature, ticlike contractions of upper torso and face, and facial flushing. The onset usually follows some stressful period in middle-life and there is no female/male predominance. The etiology is unknown but it is thought to be a vocal expression of psychoneurotic behavior. Other authors have felt it to be secondary to a CNS or proprioceptive disorder of the larynx.

2. Laryngeal findings are those of hyperadduction of the vocal cords with the patient attempting to phonate against a closed glottis.

3. Treatment modalities:

a. Psychotherapy and speech therapy reported to have uniformly poor results after long periods of intervention.

b. Surgical therapy first proposed by Dedo was to deliberately section the RLN to prevent hyperadduction of the vocal cords. This was done after temporary paralysis with

48 lidocaine (Xylocaine) and showed significant improvement in voice quality. Sectioning of the RLN in spastic dysphonia patients has resuled in greater ease and improved quality of phonation, with reduction or elimination of facial and neck grimaces in most patients. Some authors advocate crushing of the RLN as opposed to section so that permanent paralysis would not occur (Biller and Som). Other authors suggest selective sectioning of the adductor branch of the recurrent laryngeal nerve (Carpenter et al).

c. One recent study by Aaronson showed a high rate of recurrence of spastic dysphonia symptoms (39%) 1-1.5 years after RLN sectioning. This can be treated in some case by deliberate paralysis of the ipsilateral superior laryngeal nerve.

Intractable Aspiration

Intractable aspiration resulting from loss of protective laryngeal function is seen with severe brain stem or cranial nerve IX, X, ad XII deficits.

Aspiration pneumonia can be a devastating and fatal complication of an otherwise debilitating but nonfatal illness, often a neurologic disorder.

Numerous nonsurgical and surgical techniques have been proposed to prevent this intractable life-threatening condition:

1. Nonsurgical techniques:

a. Nasogastric tube supplemented by IV feeding provides a temporary solution for obtaining nutrition. Long-term use of the tube may result in rhinosinusitis, postcricoid ulceration, and chondritis of the larynx.

2. Surgical techniques:

a. Cuffed tracheotomy tube for temporary relief from aspiration. Long-term cuffed tubes may result in stomal infection, tracheal stenosis, esophageal erosion, and innominate artery fistulization.

b. Vocal cord augmentation with Teflon injection. This is never completely effective in correcting aspiration caused by high vagal paralysis.

c. Cricopharyngeal myotomy to facilitate passage of food and minimize stasis of secretions.

d. Bilateral chorda tympani and tympanic nerve sections to reduce saliva production.

e. Gastrostomy (better tolerated than nasogastric tubes on a long-term basis).

f. Separation of the larynx and trachea by creation of a tracheostoma and closure of the larynx at the level of the first tracheal ring.

g. Use of epiglottic flap to arytenoids.

49 h. Linderman's diversion procedure with tracheoesophageal anastomosis and creation of a tracheostome. In this technique, aspirated saliva and food are diverted into the esophagus. This procedure may be reversible.

i. Montgomery's glottic closure procedure. Both vocal cords are sutured together via a laryngofissure; theoretically reversible. Sasaki and coworkers described a modified method of laryngeal closure.

j. Total laryngectomy.

Voice Restoration After Laryngectomy

1. In 1931 Guttman described a technique which restored voice in several patients. He created a fistula between the trachea and the pharynx using an electrocautery needle. Ever since, numerous methods of surgical restoration of voice after laryngectomy have been described which include Asai's laryngoplasty, air bypass voice prosthesis (1975), pseudoglottis procedure (Staffieri, Sisson and Goldman).

2. Singer-Blom tracheoesophageal puncture (TEP) technique: In 1979 Singer and Blom described a technique of voice restoration that created a fistula between the top of the tracheal stoma and the tube. A soft Silastic device was inserted in the fistula to maintain its patency and to allow shunting of air from the trachea into the hypopharynx without aspiration.

In 1981, Singer and Blom described 129 patients, 88% of whom had achieved fluent voices. They noted that esophageal voice is profoundly affected by the residual function of the pharyngeal constrictor musculature. Selective division of these muscles will enhance voice acquisition in most cases of failed esophageal speakers.

3. Candidates for the Singer-Blom procedure include any motivated patient who, after total laryngectomy, has an adequate-sized tracheostoma; a pharyngoesophageal lumen adequate to permit passage of an esophagoscope; sufficient hand-eye coordination to handle and take care of the prosthesis on a daily basis, or a family member who is willing to do this for the patient; and the ability to cover the stoma with the thumb or finger to divert airflow from the lungs through the device into the esophagus. Prior radiation therapy or partial or total pharyngectomy is not a contraindication.

4. In spite of some of the postoperative problems, it appears that at the present time this is the surgical procedure of choice to vocally rehabilitate the total laryngectomy patient.

50 Tracheotomy

General Considerations

1. Tracheotomy is done to form a temporary opening in the trachea. Tracheostomy, in which the trachea is brought to the skin and sewed in place, provides a permanent opening. Tracheostomy is usually done in connection with laryngectomy.

2. Tracheotomy is indicated for two groups of patients.

a. Those who have an obstruction at or above the level of the larynx (mechanical obstruction).

b. Those who have an actual obstruction to the airway but cannot raise secretions (secretional obstruction).

Tracheotomy in the second group is becoming increasingly common.

3. Elective tracheotomy may be necessary when respiratory problems are anticipated in the postoperative period in patients being subjected to major head and neck thoracic operations or in patients with chronic pulmonary insufficiency.

Therapeutic tracheotomy is indicated in any case of respiratory insufficiency due to alveolar hypoventilation in order to bypass obstruction, to remove secretions, or to provide for the use of mechanical artificial respiration.

4. Clinical signs of upper airway obstruction include:

a. Retraction (suprasternal, supraclavicular, intercostal). b. Inspiratory stridor. c. Restlessness, apprehension, disorientation, leading to coma. d. Rising pulse and respiratory rates. e. Pallor (earlier sign) and cyanosis (late danger sign). f. Fatigue and exhaustion due to excessive efforts to breathe through an obstructed airway.

The patient's exhaustion must not be regarded as a sign of improvement, but rather a danger sign. It is a mistake to wait for late clinical signs of obstruction to appear before performing a tracheotomy. The time to proceed with the operation is whenever the possible need was first considered. Surgical manipulation in hypoxaemic patients often is associated with cardiac arrest.

5. Function of a tracheotomy: In addition to the bypass of an upper airway obstruction, tracheotomy has several other physiologic functions which include:

a. Decreasing the amount of dead space in the tracheobronchial tree, usually 70-100 mL. The decrease in dead space may vary from 10-50%, depending on the individual's physiologic dead space.

51 b. Reduction of resistance to airflow which, in turn, reduces the force required to move air. This will result in increased total compliance and more effective alveolar ventilation, provided the tracheotomy opening is large enough.

c. Protection against aspiration.

d. Enables swallowing without reflex apnea which is important in respiratory patients.

e. Access to the trachea for cleaning.

f. Pathway to deliver medication and humidification to the tracheobronchial tree, with or without intermittent positive pressure breathing.

g. Decreasing the power of the cough and thereby preventing peripheral displacement of secretions by the high negative intrathoracic pressure associated with the inspiratory phase normal cough.

6. Tracheotomy in infants and children should always be done after a bronchoscope, endotracheal tube, or catheter has been inserted to provide an airway and some rigidity to the trachea. This will convert an emergency tracheotomy to an orderly one. It is easy, in these small patients, to carry dissection too deeply and laterally to the trachea with resulting damage to the recurrent laryngeal nerve, the common carotid artery, apex of the pleura, or the cervical esophagus. Caution must be used when incising the tracheal wall not to insert the knife too deeply and lacerate the posterior wall. When the head of a child is turned or keeps moving, a trachea may be entered too laterally. A bronchoscope or endotracheal tube in the trachea will help eliminate these complications.

Indications

Indications for tracheotomy may be summarized as below:

A. Mechanical obstruction.

1. Obstructive tumors involving the larynx, pharynx, upper trachea and esophagus, thyroid gland.

a. When in advanced stage. b. Edema from radiotherapy. c. As adjunct to surgery.

2. Inflammation of larynx, trachea, tongue, and pharynx.

a. Acute epiglottitis. b. Viral croup. c. Ludwig's angina, etc.

52 3. Congenital anomalies obstructing larynx or trachea.

a. Laryngeal web or atresia. b. Tracheoesophageal anomalies, etc.

4. Trauma of larynx and trachea.

a. Cartilaginous framework and soft tissues. b. Inhalation of steam or fumes (burn).

5. Maxillofacial trauma with extensive bony and soft tissue damage.

a. Le Fort II, III, multiple fractures of mandible and maxilla, etc. b. Hemorrhage. c. As adjunct to surgery.

6. Bilateral vocal cord paralysis.

7. Foreign bodies.

8. Sleep apnea syndrome.

B. Secretional obstruction.

1. Retained secretions and inadequate cough.

a. Thoracic and abdominal surgery. b. Bronchopneumonia. c. Burns aboute face, neck, and respiratory tree. d. Conditions producing coma, i.e. diabetes mellitus, uremia, septicemia, and liver failure.

2. Alveolar hypoventilation.

a. Drug intoxication and poisoning. b. Flail chest, fractured ribs, and surgical emphysema. c. Paralysis of chest wall. d. Chronic obstructive pulmonary disease, i.e. emphysema, chronic bronchitis, atelectasis, bronchiectasis, and asthma.

3. Both retained secretions and alveolar hypoventilation.

a. Central nervous system disease, i.e. stroke, encephalitis, Guillan-Barre syndrome, poliomyelitis, and tetanus. b. Eclampsia. c. Massive head and chest injuries. d. Neurosurgical postoperative coma. e. Air and fat embolism.

53 f. Several of the conditions noted in (a) and (b) may include both alveolar hypoventilation and retained secretions.

Technique

Refer to standard textbooks.

Postoperative Considerations

1. Immediate postoperative chest x-rays (AP and lateral) are important to ascertain the length and position of the tracheotomy tube and to rule out complications of tracheotomy such as pneumomediastinum or pneumothorax.

2. The inner cannula of the tracheotomy tube should be removed and cleaned every 1-2 hours for the first 2 or 3 days to prevent obstruction by dried mucus. This is especially important in infants.

3. A tracheotomy tube in a fresh tracheotomy should be left in place 2-3 days before it is changed. By this time a permanent tract exists and there is little danger of being unable to reinsert the tube. Changing a tube before this time may result in loss of the tracheal opening into the neck wound with possible fatality.

4. A string around the neck should never be loosened "for comfort". The tube may slip out of the fresh tracheotomy wound.

5. Suctioning must be done often, especially during the first few days after tracheotomy because of the increase in tracheobronchial secretions secondary to tracheal irritation.

6. A tracheotomy should be left in place no longer than necessary, especially in children. Removal as soon as it is expedient will help reduce the incidence of tracheobronchitis, tracheal ulceration, tracheal stenosis, tracheomalacia, and persistent tracheocutaneous fistula.

Complications

Complications of tracheotomy may be summarized as follows:

A. Immediate.

1. Apnea. 2. Hemorrhage. 3. Pneumothorax and pneumomediastinum. 4. Subcutaneous emphysema. 5. Malpositioned tube. 6. Tracheoesophageal fistula. 7. Recurrent laryngeal nerve paralysis. 8. High tracheotomy (injury to the cricoid cartilage).

54 9. Aerophagia. 10. Aspiration of gastric contents.

B. Delayed.

1. Delayed hemorrhage. 2. Tracheoesophageal fistula. 3. Tracheocutaneous fistula. 4. Displacement or obstruction of a tube and a cuff. 5. Atelectasis and pulmonary infection. 6. Tracheomalacia. 7. Dysphagia. 8. Difficult decannulation. 9. Problems with neck scar. 10. Tracheal stenosis.

a. Apnea: When tracheotomy is performed on a patient with a history of chronic hypoxia, the patient may take one or two breaths right after the procedure and then suddenly become apneic. This is due to physiologic denervation of the peripheral chemoreceptors by the sudden increase of PO2, and because hypoxia may be largely responsible for respiratory drive in these patients, apnea results. Some form of respiratory assistance is necessary until

enough CO2 is removed to allow a return of sensitivity of central chemoreceptors. The patient should never be left unattended after an emergency tracheotomy.

b. Hemorrhage: This may occur if hemostasis is not secured at operation.

c. Pneumothorax and pneumomediastinum: Pneumothorax may be caused by injury to the cupula of the pleura which rises into the neck in infants and young children and is subject to injury during the operative procedure. This usually occurs when the tracheotomy is done without prior establishment of an airway by a bronchoscope or an endotracheal tube.

Pneumomediastinum may result from air being sucked through the wound in a child severely obstructed and having violent respiratory movements, or it may result from excessive coughing which forces air into the deep tissue planes of the neck, which then dissects into the mediastinum. Should the parietal pleura rupture, pneumothorax will result. Pneumomediastinum may require no surgical therapy, but pneumothorax often requires the placement of chest tubes with an underwater seal.

d. Malpositioned tube: This is a frequent complication. Careful preoperative selection of a tube followed by postoperative roentgenographic evaluation will prevent this complication. Tubes of excessive length may impinge on the anterior wall of the trachea or the carina producing partial tracheal obstruction as well as ulceration and possible rupture of the innominate artery. The tube may extend down one bronchus with resultant atelectasis of the opposite lung. Too short a tube may predispose to displacement of the tube out of the trachea, especially when the neck is flexed in obese individuals or small children.

e. Tracheoesophageal fistula: This results from penetration through the muscular posterior tracheal wall into the esophagus, or approaching the trachea from the side. Recurrent

55 laryngeal nerve injury rarely occurs. These complications can be avoided by dissecting the midline of the neck and by inserting a rigid endotracheal airway.

f. Aerophagia: Aerophagia is seen most often in infants and young children and should be recognized as a cause of persistent dyspnea. It is treated with nasogastric tube decompression of the swallowed air. Death of an infant secondary to aerophagia with respiratory compromise has been reported.

g. Delayed hemorrhage: This is most often due to erosion of a major vessel by pressure necrosis from the cuff, or occasionally, the tip of the tracheotomy tube. Any bleeding occurring 4-5 days postoperatively should be given careful and immediate attention because of the threat that it may represent erosion into a major vessel. The innominate artery is the vessel most commonly involved with the common carotid, inferior and superior thyroid arteries, aortic arch, or occasionally, the innominate vein.

Mathog et al proposed possible preventative measures, which include the following: (1) adequate skin incision to allow visualization of palpation of abnormal vessels; (2) avoidance of a "low" tracheotomy, i.e. minimal extension of the head, gentle traction with a tracheal hook, and the stoma placed in the second and third tracheal rings; (3) elimination of metal tubes, with the use of plastic or silicone rubber tubes without a cuff and roentgenographic guidance to be certain the position and length of tubes are appropriate; (4) high humidity and aseptic care of the tracheotomy.

h. Delayed tracheoesophageal fistula: This is usually fatal and results from severe pressure necrosis from an overinflated cuff or from the tip of a malpositioned tube, the erosion occurring through the posterior tracheal wall and the anterior wall of the esophagus. Typically, the aspiration through the fistula results in severe pneumonitis.

i. Difficult decannulation: This is a frequent complication in children. A tracheotomy tube should be decannulated within 8-10 days (or sooner) whenever possible. If not, decannulation becomes difficult because (1) the child gets used to less resistance and less effort (tracheotomy decreases the dead space), (2) the child forgets the apneic reflex during deglutition, and (3) tracheal collapse develops.

j. Neck scar: The use of a vertical skin incision is the most frequent cause of unsightly scar formation. The duration of tracheotomy is also important in scarring which is lessened by early removal of the tube. Vertical contracture and widening of a hypertrophic scar will require a Z-plasty for repair.

k. Tracheal stenosis: Stenosis of the larynx follows injury and perichondritis of the cricoid cartilage which is the only circular tracheal support. Tracheal stenosis is most common in children and thought to result from excision of cartilage from the anterior tracheal wall. Exuberant granulations may develop on the anterior tracheal wall due to delayed epithelialization when there is a large defect in the anterior tracheal wall, and may cause obstruction and bleeding.

Tracheotomy related subglottic stenosis may be related to bacteriologic pathogenesis via tracheostomal contamination. Therefore the ability to control stomal contamination with

56 topical and/or systemic antibiotics may play a role in the prevention of the wound infection leading to cicatrical scar and stricture.

Endotracheal Intubation

1. Nasotracheal intubation in acute epiglottitis has been recommended. A smooth polyvinylchloride tube of somewhat smaller caliber than that corresponding to the patient's age is used. After intubation, children are placed in a cool-oxygen tent. The tube is tolerated well. Duration of intubation is usually 24-48 hours. Because most children with acute epiglottitis must be intubated to be tracheotomized, and because the critical perior for airway obstruction is at most 48 hours, nasotracheal intubation may be preferable to acute tracheotomy in a severely ill child. However, for those who are responsible for the occasional case, it is safer to rely on the time-tested tracheotomy. Endotracheal intubation should be done only by an experienced anesthesiologist or otolaryngologist.

2. There has been renewed interest in prolonged endotracheal intubation. Autopsy study showed:

a. Total damage and laryngeal ulceration in the intubated larynx and trachea were statistically related to duration of intubation but not to age or sex of the patient.

b. Significant ulcerations were confined to the posterior half of the larynx and the anterior and lateral aspects of the trachea between the third and tenth rings.

c. Intubation beyond 48 hours was associated with significant laryngeal ulceration, increasingly severe vocal process perichondritis, and frequent infection by microorganisms.

d. Intubation beyond 96 hours was associated with severe damage to the vocal processes and the subglottis, and a higher incidence of inferior vocal fold ulceration.

e. Tracheal damage in patients with multiple intubations or extubation before death was similar to that in the continuously intubated patients, but inflammation was more widespread and deeper.

f. Orotracheal intubation of adults for more than 96 hours may cause permanent damage.

3. Causes of inadequate ventilation with intubation include:

a. Mucus or clot obstruction. b. Herniation of the cuff down over the end of the tube. c. Collapse of the beveled end of the tube so as to block the lumen. d. Lodging of the open portion of the beveled tube against the tracheal wall so as to occlude its lumen. e. Kinking of the proximal unarmored end of the tube at its attachment to the adaptor. f. Collapse of the endotracheal tube lumen by the inflated cuff.

57 Tracheotomy and Laryngeal Function

Prolonged tracheotomy may result in aspiration due to a weakened, ill-coordinated adductor reflex response resulting from behavioural alterations of medullary adductor motor neurons. Experimental evidence has show that phasic abductor activity in the posterior cricoarytenoid muscles diminishes as ventilatory resistance decreases. When airflow is shunted through a tracheotomy, abductor activity not only gradually diminishes, but completely disappears. The longer the duration of decreased ventilatory resistance, the more difficult it is to reestablish the abductor function once it is lost. This helps to explain the difficulty encountered in tracheotomy decannulation and fusion of denuded vocal cords (after endotracheal intubation injuries) when laryngeal abductor activity is lost resulting in the absence of phasic inspiratory abduction.

Neurologically Intact Larynx Before Tracheotomy. Vocal cords abduct and elongate on inspiration secondary to activation of the PCA (producing abduction) and CT muscle (producing elongation). During expiration the cords close to the median position (CT muscle adduction).

Neurologically Intact Larynx After Tracheotomy. Vocal cords remain in the intermediate position in both phases of the respiratory cycle. Decreased airway resistance produced by tracheotomy abolishes the physiologic activity of both the PCA and CT muscles. Therefore tracheotomy can and will cause lateralization of a paralyzed cord (in acute low vagal or RLN paralysis) and this should be considered in determining the neuroanatomic site of injury.

Sleep Apnoea

The sleep apnea syndrome (SAS) is now recognized as an important clinical entity caused by repetitive episodes of upper airway tract obstruction during sleep. If unrecognized and untreated this condition may lead to death.

1. Apnea is the cessation of airflow at the level of the nares and mouth, and is classified into three different types: (1) central, (2) obstructive or peripheral, and (c) mixed.

2. Central apnea occurs when the respiratory center fails to initiate a respiratory effort. Obstructive or peripheral apnea is the cessation of nasal and oral airflow with persistence of respiratory efforts. Respiratory efforts are manifested by a rocking movement of the chest and abdomen, and retraction of the intercostal and suprasternal spaces. Mixed apnea is a combination of central and obstructive apnea.

3. The duration of pathologic apnea episodes vary with age. Apnea episodes longer than 10 seconds for adults, 15 seconds for infants (up to 6 months old), and 20 seconds for premature infants are considered pathologic.

4. The sleep apnea syndrome is characterized by the presence of at least 30 true apneic episodes in both REM (rapid eye movement) and non-REM sleep, during 7 hours of unsedated nocturnal sleep. In the adult sleep apnea syndrome, the number of apneic episodes is usually several hundred per night.

58 5. The incidence of sleep apnea syndrome is unknown. However, its occurrence is probably underestimated.

6. The spectrum of this syndrome encompasses all age groups, being particularly prominent among the following:

a. In infancy where it may take the form of the sudden infant death syndrome (SIDS).

b. In early childhoo where it is associated with inflammatory diseases and hypertrophy of nasal and oropharyngeal structures.

c. In adults where it is commonly seen in obese white males in the fifth decade of life. Adults usually are affected by a central or mixed type of apnea, whereas children exhibit obstructive apneic spells in the majority of cases. There is a striking male preponderance in most reports of sleep apnea syndrome (20:1 to 60:1).

7. Central (medullary) chemoreceptors, peripheral (carotid body) chemoreceptors, and mechanoreceptors play a significant role in the physiology of respiratory control. Ventilation

is increased upon stimulation of the medullary chemoreceptors by an increase in PCO2. Carotid body chemoreceptors, located at the bifurcation of the common carotid arteries are responsive to PCO2, H+, and PO2, and transmit their neural messages to the brain stem respiratory centers via the carotid sinus nerve (branch of the glossopharyngeal nerve). Mechanoreceptors consist of bronchopulmonary and chest wall subgroups. The former transmits neural activity to the brain stem respiratory centers via cervical vagal fibers.

8. The precise etiology of the sleep apnea syndrome is unknown. However, it is felt that a disarrangement of the neurologic control of the pharyngeal airway is an essential factor. The pharyngeal airway is the most compliant part of the upper airway due to its lack of skeletal support. Patency of the pharyngeal airway during sleep is maintained by the involuntary adjustment of muscular tone via the central nervous system. During inspiration the pharyngeal muscles must increase their tone to overcome the tendency of the pharyngeal airway to collapse. Patients with the sleep apnea syndrome may exhibit an aberration of this control mechanism. Fiberoptic studies of patients with obstructive SAS demonstrate recurrent closure of the velopharyngeal sphincter with opposition of the lateral pharyngeal walls at the level of the superior constrictor muscle.

9. Obstructive causes of SAS include:

a. Adenotonsillar hypertrophy. Adenoidal hypertrophy alone (normal tonsils) can cause cor pulmonale, systemic and pulmonary hypertension. b. Nasal obstruction (septal deformity). c. Nasopharyngeal abnormalities (stenosis, pharyngeal flap repair of palatal clefts or velopharyngeal insufficiency). d. Pharyngeal obstruction (vallecular cysts, lingual tonsils). e. Laryngeal obstruction (congenital webs, vocal cord paralysis, obstructive polyps and cysts, etc). f. Craniofacial anomalies with posterior displacement of the hypomandibular complex (Pierre Robin syndrome, Treacher Collins' syndrome).

59 10. Approximately 80% of adults with obstructive sleep apnea present with daytime hypersomnolence. Other daytime symptoms include early morning headaches, easy fatigability, personality change, intellectual deterioration, poor memory, behavior problems, poor job and school performances. Nighttime symptoms include loud snoring, restlessness, somnambulance, nocturnal enuresis, insomnia, and nightmares.

One-third of sleep apnea patients are overweight and 25-60% are hypertensive. Digital clubbing, nasal polyps, facial and thoracic abnormalities, and endocrine disorders all serve as supportive evidence of SAS.

11. Arrhythmias are found in almost all patients with sleep apnea syndrome (up to 96%). These included sinus bradycardia, asystole, sinus arrhythmias, ventricular and sinus tachycardias, and 2° AV block.

12. There is increasing evidence of an association between sudden infant death syndrome and apnea during sleep. The incidence of SIDS is 2-3% per 1000 live births, with a definite male predominance. Ninety-one percent of the deaths occur before 6 months of age. Postmortem examinations of these infants have revealed pulmonary vasculature hypertrophy suggestive of chronic hypoxia prior to death. Pulmonary petechial hemorrhages also are found, suggestive of marked negative intrathoracic pressure (i.e. caused by trying to breathe against an obstruction).

13. The diagnostic evaluation of patients with sleep apnea syndrome usually involves polysomnographic monitoring since the physical examination is often benign. Polysomnographic monitoring consists of a graphic recording of extraocular movements, EEG, ECG, oral and nasal thermistors, and an abdominal strain gauge. This evaluation documents the relationship between the respiratory irregularity and the disturbed EEG pattern. The percentage of total sleep time spent in apnea is calculated, and further studies are undertaken (i.e. videofluoroscopy, nasopharyngoscopy) if the apnea is of the obstructive type and of significant duration (greater than 1% of total sleep time). Continuous skin surface electrodes provide and alternate method of documenting alveolar hypoventilation in a noninvasive manner.

14. Management modalities for central apnea include the following: methyl xanthines for infantile apnea, progesterone, theophyline, diaphragm pacing, acetazolamide, and tricyclid antidepressants have been used for adults.

Management of obstructive sleep apnea syndrome includes the following: specific reconstruction for orofacial anomalies, T and A for adenotonsillar hypertrophy, nasal surgery for nasal airway obstruction, oral and laryngoscopic surgery for hypopharyngeal and laryngeal obstruction, weight reduction, and endocrinologic evaluation and treatment. Obstructive areas not amenable to surgery must be bypassed with either nighttime nasopharyngeal airway tubes or tracheotomy.

60 Laser in Otolaryngology

Carbon Dioxide Laser

Biophysics

1. The word LASER is an acronym derived from the first letters of the words light amplification by stimulated emission of radiation.

2. A laser is a device for converting some form of "pumping" energy, such as heat, light, or electricity, into radiant energy of a special kind at one or more discrete wavelengths.

3. When the wavelength of radiant energy lies within the visible portion of the electromagnetic spectrum, it is called light, with which we are all familiar. However, not all lasers emit their radiant energy as light, and even those which do emit light produce a kind not found in natural phenomena.

4. The radiation emitted by all lasers has three special qualities:

a. It is coherent. b. It is highly collimated. c. It is monochromatic.

Coherent means that all the waves are exactly in phase (step) with each other in both space and time. Collimated means that the rays are parallel to each other. Monochromatic means that all the waves have exactly the same wavelength (or color, if they are visible).

5. The first lasers were made in the later 1950s and early 1960s. These early lasers utilized gems, such as rubies, through which radiant energy was passes or pumped through. Atoms in the ruby were stimulated or "excited" by the energy to cause them to emit coherent, collimated, and monochromatic radiation. This radiation could be focused with lenses and mirrors into a beam of enormously concentrated energy.

6. Early lasers were not very efficient, converting only about 1% of the "pumping energy" into laser energy. Lasers that utilized gases such as argon, neon, and carbon dioxide turned out to be much more efficient, converting as much as 15% of the incoming energy into laser energy. Also gas lasers can produce a continuous beam while a ruby laser produces a beam only in short pulses.

7. About one decade ago, the first practical gas lasers were developed. The most

efficient of these is the carbon dioxide (CO2) laser, converting about 15% of its pumping energy into coherent output radiation. The primary radiant output of the CO2 laser occurs at a wavelength of 10.6 microm (a micron is one-millionth of a meter). This is in the infrared portion of the spectrum, where it is invisible to the human eye. Because of its relatively high efficiency and the fact that the lasing medium is a gas, so that cooling the laser is easy, it can be operated as a continuous-wave (not pulsed) device at power outputs up to 500 W or more.

61 8. The radiant waves from the CO2 laser at 10.6 microm are ideal for surgical removal of tissue because:

a. They are strongly absorbed by all solids (except metals and certain metallic compounds), and by liquids, notably water, which is the major constituent of most living cells. In water, nearly all the radiant energy is absorbed within a depth of 100 microm from the irradiated surface. b. They are not significantly scattered laterally from the target point. c. Their absorption is not dependent on the color of the tissue. d. They do not cause genetic mutation of the cells' nuclei (which may occur with

gamma rays and x-rays). The physical effect of the waves from the CO2 laser in any absorbing material is conversion of their radiant energy to heat. e. They destroy cells and their nuclei (including those of bacteria) by flash boiling of the cellular water, which takes place at 100°C. f. Because they are continuous waves, not pulsed, their average power is equal or comparable to their peak power. Thus there is no risk of causing a blast effect around the point where the laser beam strikes the tissue (a problem which makes pulsed lasers hazardous for many surgical uses). g. They can be efficiently reflected from mirrors made of highly polished metals like stainless steel, which steer the laser beam under the manual control of the user. h. They can be focused to very small spots (2 mm or less) by low-loss lenses made of special metallic compounds covered with ultrathin, antireflective coatings. i. When deliberately defocused, they can be used to coagulate blood and seal small vessels in vascular tissue without vaporization of cells.

j. The CO2 laser system delivering enough power for surgery is compact and operable from an ordinary electric wall outlet.

Laser Surgery in Otolaryngology

It has been found that the carbon dioxide laser provides a practical method of tissue ablation or excision which can be carried out with excellent control. The laser beam is directed with a hand piece in the oral cavity, with the surgical microscopic laser attachment (micromanipulator) in the nose, pharynx, and larynx, and with the endoscope-bronchoscope assembly in the tracheobronchial tree.

Laser surgery appears to be most valuable when precise surgery is needed to preserve function.

The laser beam can be used to vaporize predetermined volumes of tissue in a precisely controlled fashion by using an appropriate amount of energy. A control knob sets the power level of the beam and a foot-switch-controlled interval times operates the shutter allowing the beam to impact on the target area for an appropriate period. For precise microsurgery, a power setting of 15 W is commonly combined with a time exposure of 0.20 sec; for gross dissection 15-25 W of power may be used continuously in the manual mode, bypassing the timer, using the foot switch to start and stop the dissection. In contrast to pulsed lasers, the continuous-wave carbon dioxide laser has comparatively little impact shock effect, so that it has minimal tendency to scatter soft tissue.

62 Clinical Application

Otolaryngologic application of CO2 laser includes:

1. Excision of benign lesions of:

a. Larynx (polyps, nodules, granuloma, papilloma, hemangioma, leukoplakia, web, subglottic stenosis, etc). b. Trachea and bronchus. c. Nose (papilloma, polyps, granuloma, hereditary telangiectasia, rinophyma, etc). d. Oral cavity (lesions of tongue, palate, valleculae, hypopharynx, tonsil fossae). e. Nasopharynx (with stainless steel mirror; recurrent adenoids, other inaccessible lesions).

2. Excision and palliation of malignant lesions of the oral cavity, hypopharynx, larynx, trachea, and bronchus.

a. Early cancer in these regions can be cured by laser excision. b. Use of laser for malignant lesions is for diagnosis (biopsy), debulking, improved airway, and cure.

3. Surgical procedures such as:

a. Excision and repair of choanal atresia (Healy). b. Partial turbinectomy. c. Intranasal antrostomy. d. Palatine tonsillectomy. e. Lingual tonsillectomy. f. Arytenoidectomy. g. Partial epiglottidectomy.

Advantages

1. Precise excision. 2. Rapid tissue destruction. 3. Reach inaccessible sites. 4. Excellent hemostasis. 5. Minimal postoperative edema, pain, and scarring. 6. Avoid tracheotomy. 7. Minimize hospitalization.

Disadvantages

1. Costly. 2. Time consuming. 3. May be harmful to patients and operating room personnel if proper precautions are not taken.

63 Precautions

1. Protect eyes. 2. Protect adjacent tissues. 3. Avoid flammable anesthetics. 4. Protect endotracheal tubes. 5. Keep protective gauze wet.

Management of Complications

1. Complications of CO2 laser microlaryngoscopy are generally associated with striking unprotected materials in the airway or unprotected tissues of the patient or operating room personnel. To reduce the risk of ocular damage the patient's eyes should be covered by moistened eye pads and all operating personnel should wear plastic protective glasses. The

radiation emitted by the CO2 laser is predominantly absorbed in the cornea, not the retina, and gross corneal opacification can result from thermal denaturation and coagulation of proteins.

2. Precautions should be taken to avoid endotracheal tube ignition during CO2 laser surgery. This involves wrapping the tube with reflective aluminium tape and placing moist neurologic cottonoids to cover the entire balloon.

3. Results of irradiating polyvinyl chloride and red rubber tubes indicate that red rubber is less flammable and therefore safer to use in conjunction with the CO2 laser.

4. Management of endotracheal tube ignition involves the following:

a. Remove the damaged tube while the patient is paralyzed to facilitate reintubation without laryngospasm. b. Intravenous steroids and antibiotics are given as if treating a tracheal or pulmonary burn. c. Intraoperative bronchoscopy is performed to remove any charred debris and assess the extend of damage. d. Delayed extubation with reexamination of the subglottic and trachea may be needed to assess the extent of further airway compromise.

Argon vs. CO2 Laser

1. The CO2 laser is an ideal for incising, excising, vaporizing, or debulking soft tissue masses with precision and good visibility. Because the argon wavelength (0.488-0.515

microm) is shorter than that of the CO2 (16.6 microm), it is possible to generate a smaller spot with the argon under similar working conditions. As a visible beam, the argon wabelength is easily transportable by fiber optic light carriers. These two factors make the argon laser more suitable for precise otologic microsurgery. As a soft tissue laser the preferential absorption of argon radiation by red tissue makes it possible for the first time to eliminate hemangiomatous lesions without physical contact and with minimal disturbance of the overlying skin.

64 2. The CO2, which has the infrared wavelength (10.6 microm) is efficiently absorbed by water and since biologic tissues contain 80% water, it is an ideal medium for absorbing infrared radiation. The argon wavelength (0.48 microm) is in the visible blue green spectrum and preferentially absorbed by a red medium.

3. The primary effect of CO2 laser is vaporization while that produced by the argon is photocoagulation.

4. Characteristics of argon and CO2 lasers are shown in Table 15.2.

Table 15-2. Comparison of CO2 and Argon Lasers

Characteristics Argon CO2 Energy Thermal Thermal Wavelength Visible (0.48 microm) Nonvisible (10.6 microm) Color Blue green Infrared Intensity 1-10 W 10-100 W Spot size 0.1 mm 1 mm Cooling system Open Closed Fiberoptic Yes No.

Applications of Argon Laser in Otology

1. Myringotomy. 2. Ear canal osteoma. 3. Tympanoplasty. 4. Stapedectomy (Perkins 1980). 5. Hemostasis. 6. Lysis of adhesions. 7. Acoustic neuroma surgery (Glasscock 1981).

Because of the nature of the CO2 beam, it is necessary to mount the laser itself onto the operating microscope, thereby making it difficult to adapt to otologic microscurgery. The ability of the argon laser to be transferred through a fiberoptic bundle has made it possible to introduce a whole new concept to microsurgery of the ear and adjacent structures.

65 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 16: Oral Cavity, Oropharynx, and Esophagus

Part 1: Oral Cavity

Anatomy: Special Points

Ducts in Oral Cavity

1. Parotid (Stenson's) 2. Submaxillary (Wharton's) 3. Sublingual (Rivinus')

Suprahyoid Muscle Innervation

1. Mylohyoid: V3 2. Anterior belly digastric: V3 3. Posterior belly digastric: VII 4. Stylohyoid: VII 5. Geniohyoid: XII

Papillae

Papillae cover the anterior two-thirds of the tongue and include: filiform (no tastebuds), fungiform, and foliate. Circumvallate papillae are a V-shaped group of large papillae that occurs at the junction of the anterior two-thirds and posterior one-third of the tongue.

Sulcus Terminalis

This is a bilateral groove that separates the anterior two-thirds from the posterior one- third of the tongue.

Foramen Cecum

The foramen cecum is a pit at the junction of the two grooves which form the sulcus terminalis from which the embryologic thyroid tissue begins its descent.

Frenulum

The frenulum is the anterior fold of mucous membrane that attaches the tognue to the floor of the mouth. Whartons' ducts open on either side of the frenulum.

Lingual Tonsil

The lymphoid tissue that extends over the base of the tongue (posterior one-third) is the lingual tonsil.

1 Vallecula

The valleculae are depressions (pockets) created by the glossoepiglottic folds at the base of the tongue and lingual surface of the epiglottis.

Extrinsic Muscles of the Tongue

These muscles include the genioglossus, hyoglossus, styloglossus, and palatoglossus. All are innervated by cranial nerve XII.

Intrinsic Muscles of the Tongue

The muscle bundles are separated by fibrous septa, the strongest of which lies in the midline (septum linguae). The four groups include the superior and inferior longitudinal, vertical, and transverse. All are innervated by cranial nerve XII.

The intrinsic muscles change the shape of the tongue which assists in speaking and swallowing.

Afferent Nerves from the Tongue

Innervation of the mucous membrane is from C1 and C2 that accompany the hypoglossal and lingual nerves, and via the glossopharyngeal and the superior laryngeal branch of X. Touch, pain, temperature, and taste are transmitted.

Blood Supply of the Tongue

1. Lingual artery: second branch of the external carotid 2. Lingual vein: does not travel with the lingual artery but with the hypoglossal nerve. Bleeding from this vein often leads to clamping of the hypoglossal nerve during surgery. 3. Lymphatics of the tongue drain into two separate systems. The anterior tongue is drained bilaterally by both a central and marginal system.

The posterior drainage system runs through the pharyngeal wall to both deep cervical chains (jugulodigastric).

Taste

1. Base of tongue: IX (bitter) 2. Anterior two-thirds of tongue: (lingual nerve, chorda tympani); VII (sweet) 3. Palate and buccal mucosa: (sour).

Palate

The hard palate forms two-thirds of the palate and consists of the palatine processes of the maxilla and the horizontal plates of the palatine bones. The soft palate is a fibromuscular shelf. The muscles that are involved include: palatoglossus (anterior pillar),

2 palatopharyngeus (posterior pillar), levator veli palatini, tensor veli palatini, and musculus uvulae.

Palatoglossus --> Contracts lateral dimension Palatopharyngeus --> Contracts lateral dimension Musculus uvulae --> Alters the uvula Levator veli palatini --> Raises the soft palate to contact the posterior pharyngeal wall Tensor veli palatini --. Pulls the soft palate laterally to give rigidity and firmness.

Nerve Supply

Motor

The mandibular nerve (V3) innervates the tensor veli palatini. The remainder of the palatal muscles are innervated by the pharyngeal plexus, IX and X. Sensory innervation to the palate is from nerves V2, VII, IX, X, sympathetic chain.

Vascular Supply of the Palate

1. Maxillary artery --> descending palatine artery: greater and lesser palatine arteries. 2. Hard palate veins --> pterygoid plate --> internal jugular vein. Soft palate veins --> pharyngeal plexus --> internal jugular vein or --> external palatine vein --> tonsil fossa --> facial vein or pharyngeal vein.

3. Lymphatics

Hard and soft palate: upper deep cervical nodes and retropharyngeal nodes.

Muscles of Mastication

All of the muscles of mastication are innervated by V3: masseter, temporalis, lateral pterygoid, medial pterygoid.

NB: The stylopharyngeus is the only muscle innervated by cranial nerve IX. Sensory innervation by the IX nerve includes base of tongue, tonsillar fossa, and soft palate.

Muscles of the Pharynx

1. Salpingopharyngeus 2. Stylopharyngeus 3. Palatopharyngeus.

These muscles are supplied by the pharyngeal plexus and the glossopharyngeal nerve. They elevate and dilate the pharynx during swallowing.

The external muscles run in an oblique direction and act as constrictors.

3 Superior Constrictor

The superior constrictor arises from the medial pterygoid plate, the base of the tongue, and mandible. It inserts, as do all constrictors, in the median raphe, and interdigitates with its corresponding muscle of the opposite side.

Medial Constrictor

This muscle arises from the hyoid bone and the stylohyoid ligament.

Inferior Constrictor

The inferior constrictor arises from the cricoid and thyroid cartilages. This constrictor may have additional innervation from the external branch of the superior laryngeal nerve.

Passavant's Ridge

Passavant's ridge represents the superior interdigitation of the superior constrictor muscle.

Pharyngeal Fascia

The pharyngeal fascia is not prominent except where there are areas of absent muscle. Two major fasciae are recognized:

1. Pharyngobasilar fascia: hangs the pharynx from the skull and the superior vertebrae. 2. Buccopharyngeal fascia: attaches posteriorly to the median raphe and the prevertebral fascia. This fascia prevents retropharyngeal abscess from crossing the midline.

Teeth The child has 20 deciduous teeth; the adult has 32 permanent teeth.

Deciduous Medial incisors (7 months) Lateral Incisors (9 months) First molar (15 months) Canine (18 months) Second molars (20-14 months)

Permanent First molar (6 years) Medial incisor (6-7 years) Lateral Incisor (8-9 years) First premolar (10-11 years) Canine (10.5 to 11.5 years) Second premolar (11-12 years) Second molar (12-13 years) Third molar (17-25 years).

4 Saliva

1. 1500 mL/day 2. pH: 6.2-7.4 3. 99.5% water, 0.5% organic/inorganic solids 4. Organic component: glycoprotein

5. Electrolytes:

a. Na 10 mEq/L b. K 26 mEq/L c. Cl 10 mEq/L d. Bicarb 30 mEq/L.

Disorders of the Oral Cavity

Dental Plaque

Dental plaque is a soft amorphous deposit which accumulates on the surface of teeth consisting of bacteria, leukocytes, and desquamated epithelium.

Pathology includes:

1. Caries 2. Periodontal disease.

Dental Development Abnormalities

1. Anodontia (partial or complete); hereditary. 2. Dilaceration: The tooth root, as a result of trauma, fails to develop normally resulting in an angular malformation of the root. Associated diseases include rickets and cretinism. 3. Supernumerary teeth. 4. Enamel hypoplasia.

Periapical Disease

1. Granuloma (asymptomatic). 2. Alveolar abscess may lead to:

a. Sinusitis b. Osteomyelitis c. Ludwig's angina d. Bacteremia.

3. Radicular cyst.

5 Inflammation of Oral Mucosa

Stomatitis

Stomatitis is generalized inflammatory involvement of the oral mucosa and includes:

1. Gingivitis 2. Periodontitis (pyorrhea) 3. Periodontosis

a. Chronic degenerative destruction of the periodontal tissue b. Papillon-Lefevre syndrome: periodontosis, hyperkeratosis of the soles and palms with calcification of the dura.

4. ANUG (acute necrotizing ulcerative gingivitis), Vincent's angina, trench mouth

a. Fetid odor to breath b. Excessive salivation c. Bleeding gingiva d. Organism: Borrelia vincenti (fusiform bacillus) e. Treatment: good oral hygiene, penicillin.

5. Herpetic gingivostomatitis

6. Herpes labials (most common viral infection of the mouth)

7. Herpes zoster

8. Herpangina (group A coxsackievirus)

9. Infectious mononucleosis

10. Noma (fusospirochetal and streptococcal or staphylococcal) (cancrum oris)

a. Usually in debilitated children b. Children more frequent than adults c. Acute gangrenous process with high mortality.

11. Bacterial

a. Streptococcal b. Staphylococcal c. Gonoccal

12. Thrush (Candida albicans)

13. Actinomyces

6 14. Blastomycosis

15. Histoplasmosis (Histoplasma capsulatum)

16. Pyogenic granuloma.

Noninfectious Lesions

1. Recurrent aphthous ulcer

a. Sutton's disease: variant with multiple, large deep ulcers which cause extensive scarring of the oral cavity

2. Erythema multiforme

3. Pemphigus vulgaris (intraepidermoid bullae)

4. Pemphigoid (subepidermoid bullae)

5. Lichen planus

6. Systemic lupus erythematosus.

Oral Mucosal Manifestations of Systemic Processes

1. Pernicious anemia: Mucosa and lips are pale yellow gray and susceptible to ulcerations. The tongue is shiny, smooth, and red.

2. Iron deficiency anemia: Oral mucosa is ash gray (Plummer-Vinson syndrome).

3. Sickle cell anemia: Stepladder alignment of the trabeculae of the interdental septum. Pallor, yellow discoloration to mucosa.

4. Thalassemia (Mediterranean): Pallor and cyanosis.

5. Polycythemia: Bright blue red with gingival bleeding.

6. Osler-Wever-Rendu: Spiderlike blood vessels (hereditary hemorrhagic telangiectasia).

7. Sturge-Weber: Telangiectasis, vascular hyperplasia, enlargement of the gingiva associated with intercranial arterovenous malformation.

8. Thrombocytopenic purpura: Petechia and hemorrhagic vesicles.

9. Menopausal (senile atrophy). Gingivostomatitis (dry, burning sensation), diffuse erythema, shininess, and occasional fissuring in the mucobuccal fold.

7 10. Nutritional pathology (deficiency):

a. Riboflavin: Atrophic glossitis, angular cheilosis, gingivostomatitis. b. Pyridoxine: Angular cheilosis. c. Nicotinic acid: Angular cheilosis, glossopyrosis with burning. d. Vitamin C: Gingivitis and "bleeding gums".

Pigmentation Changes to Oral Cavity

1. Melanosis (physiologic pigmentation).

2. Peutz-Jeghers syndrome: Brown (melanin).

3. Bismuth: Black.

4. Arsenic: Black.

5. Lead: Blue/gray.

6. Mercury: Gray/violet.

7. Silver: Violet/blue/gray.

8. Addison's disease: Brown.

9. Hemochromatosis: Bronze.

10. Xanthomatous diseases: Yellow/gray.

Common Childhood Oral Cavity Disease Manifestations

1. Measles (rubeola): Koplik's spots

2. Chickenpox (varicella): vesicles

3. Scarlet fever: strawberry tongue

4. Congenital heart disease: gingivitis, cyanotic gums

5. Kawasaki's disease: strawberry tongue (this is due to protuberance of the tongue papillae).

Leukoplakia (White Plaque)

1. Whitish appearance which is due to hyperkeratosis of the epithelium

2. Precancerous: males/females = 9:1.

8 Median Rhomboid Glossitis

This is a developmental anomaly of the tongue in which the tuberculum impar persists in the midline. The incidence is less than 1%.

Fordyce Granules

These are painless, pinpoint yellow elevations which usually occur bilaterally in the posterior buccal spaces. They represent ectopic sebaceous glands.

NB: They frequently accompany tongue atrophy in syphilis.

Macroglossia

Etiologies:

1. Hemangioma 2. Myxedema 3. Acromegaly 4. Amyloidosis 5. Cysts 6. Actinomycosis 7. Pierre Robin syndrome (relative macroglossia) 8. Tertiary syphilis 9. Von Gierke's disease.

Tumors of the Mandible (Excluding Carcinoma)

A. Odontogenic fibroma

1. Circumscribed radiolucency 2. Area of impacted canine or moral 3. Differential: dentigerous cyst 4. Excision: no tendency toward recurrence.

B. Ameloblastoma

1. True neoplasm of enamel origin 2. Third decade 3. Majority in mandible (especially molar region) 4. Slow, expanding, painless growth 5. X-ray demonstrates a multilocular cyst (septa or spokes of bone).

C. Cementoma

1. Arise around apex of mandibular incisor 2. More common in women (second decade) 3. Rarely needs excision.

9 D. Odontoma

1. Composed of more than one kind of odontogenic tissue

E. Adenoameloblastoma

1. Well encapsulated follicular cyst 2. More common in adolescent girls 3. Frequency associated with impacted teeth.

F. Ameloblastic fibroma

1. Slow-growing, painless 2. Adolescents 3. Molar area of mandible

G. Ameloblastic sarcoma

1. Poor prognosis

H. Ameloblastic odontoma (rare)

I. Ewing's sarcoma (diffuse endothelioma of Ewing)

1. Commonly occurs between ages 10-25 years 2. Males outnumber females 3. Morphologic appearance a. Hemorrhage and necrosis common b. Fifty percent show a concentric (onion skin) layered appearance

4. Histologically: highly differentiated

5. Clinically: a. Rapid growth b. Painful c. Metastasis d. Less than 15%, 5-year survival.

Odontogenic Cysts

A. Radicular 1. Most common 2. Commonly due to an infected tooth apex 3. Usually asymptomatic 4. No transformation or malignant degeneration potential

10 B. Dentigerous (follicular)

1. Due to alteration of the enamel epithelium in the crown of a permanent tooth 2. Common in mandibular third molar or maxillary cuspid as these are the most commonly impacted teeth 3. Ameloblastoma formation has occurred in cyst wall.

C. Primordial

1. Uncommon 2. Found to normal tooth location without evidence of different tooth elements.

Other Oral Cavity Lesions

A. Erythroplasia of Qeyrat

1. Historically associated with syphilis 2. Single white plaque (well-defined) which readily changes to a red velvety surface without inflammation 3. Histologically: similar to carcinoma in situ

B. White hairy tongue

1. Accumulation of keratin on the surface of filiform papillae.

C. Epulis.

1. Least common is the congenital type which looks much like the granular cell myoblastoma. It has no malignant potential.

2. More common is the giant cell type (giant cell reparative granuloma).

a. Histology shows reticular and fibrous connective tissue with numerous giant cells. b. X-ray of the bone shows cuffing or sclerotic margins.

D. Ranula.

1. Small, painless, floor-of-mouth lesion. 2. Histology: Retention cyst. 3. Excision should include sublingual gland to prevent recurrence.

E. Torus palatinus.

1. Arise from persistent bone growth.š2. Benign.

11 F. Torus mandibularis.

1. Excessive bone growth. 2. Growth occurs past puberty. 3. Occasionally due to denture irritation.

Deglutition

A. Oral phase.

1. Voluntary. 2. Solids are masticated. 3. Saliva mixes with food bolus. 4. Bolus is molded by tongue and teeth. 5. Bolus is collected on tongue dorsum. 6. Anterior tongue elevates/base of tongue elevates. 7. Mylohyoid muscle elevates floor of mouth. 8. Hyoid is pulled up an forward. 9. Bolus is propelled into the pharynx. 10. For liquids the mouth and contents form an anatomic funnel.

B. Pharyngeal phase

1. Reflex response due to wall receptors. 2. Nasopharynx closed off (levator/tensor palati). 3. Contraction of the lingual muscles keeps the tongue against the palate. 4. Larynx closed off: a. Elevated and moved forward. c. Epiglottis. 5. Three sphincters (true vocal cords, false vocal cords, aryepiglottic folds). 6. Vertical height of pharynx is reduced by: Palatopharyngeus, stylopharyngeus, and elevation of the hyoid. 7. Circular and horizontal fibers in synchrony, move food inferiorly. 8. Cricopharyngeus opens. 9. Peristaltic waves pick up in esophagus, not pharynx.

C. Esophageal phase

1. Fluid movement is passive. 2. Peristalsis effect solids and semisolids. 3. The upper one-third of the esophagus has voluntary muscle: rapid peristaltic movement. 4. Passage in the upper one-third is less than 1 second. 5. Lower one-third is smooth muscle, with approximately 3 second passage. 6. Gravity plays only a small role in food passage in the esophagus. 7. Changes in position play a minimal or no role. 8. Reverse peristalsis is not normal.

12 9. There are bare nerve endings that will cause spasm if the esophagus is overly distended. 10. Highly coordinated feedback pathway controls gastroesophageal bolus transfer.

Swallowing Nerve Map

Sensory Receptors

1. Soft palate. 2. Mucosa at tongue base. 3. Tonsillar pillars. 4. Posterior pharyngeal wall.

Central Reception

1. (V) Gasserian ganglion. 2. (IX) Inferior (Andresch's) ganglions. Deglutition center (Myelencephalon). Superior petrosal ganglions. 3. (X) Inferior (jugular). Superior (nodose) ganglions.

Efferent Pathway

1. Teeth/jaw (V). 2. Palate (V, X). 3. Lips (VII). 4. Buccal space (VIII). 5. Pharynx (IX, X). 6. Larynx (X). 7. Esophagus (X). 8. Tongue (XII).

Part 2: Tonsils/Neck Infections/Spaces

Parapharyngeal Space

The parapharyngeal space is a potential space filled with loose conncetive tissue. It is inversely pyramidal in shape with the following boundaries:

Superior: Skull base. Inferior: Lesser cornua of the hyoid. Lateral: Ascending ramus of the mandible, medial pterygoid, interpterygoid fascia. Posterior lateral: Fascia surrounding the parotid gland. Medial: Visceral fascia on the superior constrictor. Fascia on the tensor veli palatini/levator veli palatini, and fascia of the styloglossus muscle. Anterior: Fascia directed to the lateral angle of the mandible and above to the pterygoid fascia of the fascia on the buccinator muscle. Posterior: Fascia about the carotid sheath (some authors include the styloid muscles and vertebrae).

13 Parapharyngeal Space Compartments

1. Prestyloid (anterior). 2. Retrostyloid (posterior). 3. Retropharyngeal (medial).

Compartment Contents

A. Prestyloid.

1. Internal maxillary artery. 2. Lingual nerve. 3. Inferior alveolar nerve. 4. Auriculotemporal nerve.

B. Poststyloid.

1. Internal carotid artery. 2. Internal jugular vein. 3. Cranial nerves IX, X, XI, XII. 4. Nodes. 5. Cervical sympathetic chain.

C. Retropharyngeal.

Nodes (node of Rouviere).

Pharyngeal Communication to Other Compartments

1. Paralingual. 2. Parotid. 3. Carotid. 4. Masticator. 5. Retropharyngeal. 6. Submandibular.

Tumors Involving the Parapharyngeal Space

1. Parotid.

a. Only 5% enter the parapharyngeal space but 50% of the tumors of the space are salivary. b. Neurogenous. a. Thirty percent of parapharyngeal space tumors. b. Paragangliomas, glomus jugulare, chemodectomas, glomus intravagale. 3. Sarcoma. 4. Lymphomas.

14 The Mayo series of 100 parapharyngeal space tumors revealed:

1. Mixed tumor: 43%. 2. Malignant lymphoma: 25%. 3. Schwannoma: 16%. 4. Paraganglioma: 12%. 5. Hemangiopericytoma: 2%. 6. Hemangioendothelioma: 1%. 7. Lipoma: 1%.

Fascial Planes

1. The cervical fascia lies in two planes: Superficial and deep. 2. Superficial. a. Encloses the neck and is continuous with the platysma anteriorly. b. The superior boundary is the zygoma while inferiorly attaches to the clavicle. 3. Deep. a. Superficial layer encloses the muscle compartment, the parotid, and submaxillary glands. b. Middle layer encloses the visceral organs. c. Deep layer encloses the vertebrae. d. All three layers enclose the carotid system.

The fascia that encloses the paraspinous muscles and the vertebrae attaches to the transverse processes laterally then splits into a prevertebral and alay layer. The "potential" space thus formed is the prevertebral space, running from the skull base to the diaphragm.

Directly posterior to the posterior pharyngeal wall and anterior to the alar fascia is the retropharyngeal space, extending from the base of the skull to the tracheal bifurcation.

NB: A midline raphe is formed where the superior constrictor attaches to the prevertebral fascia.

Submandibular Space

The submandibular space is bounded by:

1. Inferior: Mylohyoid muscle. 2. Lateral: Body of mandible. 3. Superior: Mucosa of the floor of the mouth.

The submandibular space is in continuity with the sublingual space along the posterior margin of the mylohyoid muscle and is bordered laterally by the anterior belly of the digastric muscle.

The visceral space lies adjacent to the esophagus and trachea. It is limited superiorly by the hyoid and readily can be contaminated by injury to either structures.

15 Deep Neck Infections

1. The oral cavity may be benign on examination. 2. Fluctuations of the neck is almost never noted.

Specific Infection Locations

Retropharyngeal Space

NB: Physical examination reveals swollen, boggy, inflamed mucosa on the posterior pharyngeal wall with unilateral swelling due to the midline raphe.

A. Diagnosis.

1. History.

a. Ethmoid or sphenoid sinusitis. b. Associated with lateral pharyngeal abscess. c. Common in children.

2. Physical examination.

a. Hyponasal speech. b. Anterior displacement of posterior pharyngeal wall. c. Posterior pharyngeal wall is soft.

3. Lateral neck film.

a. Air in the retropharyngeal space. b. Widened soft tissue shadow overlying C-2 (average 4 mm), greater than 7 mm is pathologic. c. Retrocochlear tissue at C-6 is abnormal in children (under 5 years) if greater than 14 mm, or in the adult if greater than 22 mm.

B. Treatment.

1. Control of the airway. 2. Trendelenburg's position. 3. Peroral drainage in uncomplicated infection, i.e. other spaces are not violated. 4. Antibiotics.

Lateral Pharyngeal Space

A. Diagnosis.

1. Trismus. 2. Drooling. 3. Dysphagia.

16 4. Odynophagia. 5. Physical examination: Medial displacement of the lateral pharyngeal wall and fullness in the retromandibular region. 6. Lateral neck film.

B. Treatment.

1. Control ariway. 2. Drainage procedure. a. Incision parallel to the anterior sternocleidomastoid. b. Horizontal submandibular incision. NB: The lateral pharyngeal space should never be drained from an intraoral route. 3. Antibiotics: Penicillin.

Submandibular Space Infection

A. Diagnosis.

1. Pain. 2. Dysphagia. 3. Voice quality change (hot-potato voice). 4. Swollen, red, inflamed oral (sublingual) mucosa. 5. Limited tongue mobility (see Ludwig's angina). 6. Respiratory distress.

B. Treatment.

1. Airway control. 2. Antibiotics (ampicillin, oxicillin). 3. Submental incision (horizontal). If space involved is sublingual only, it may be drained intraorally.

C. Microbiology.

1. Anaerobic streptococci (comon). 2. Staphylococcus aureus (common). 3. Hemolytic streptococci (common). 4. Bacteriodes (especially dental infections). 5. Mycobacterium tuberculosis (rare). 6. Atypical mycobacteria (rare). 7. Actinomyces (rare). 8. Nocardia (rare).

NB: Prevertebral abscess is commonly due to tuberculosis (Pott's disease).

NB: In over 50% of deep neck infections no specific source of infection is identified.

17 Ludwig's Angina

Ludwig's angina is an acute inflammatory process beginning in the floor of the mouth that invades the mylohyoid and rapidly spreads in the submaxillary space.

1. Rapid spread of infection (phlegmon, not an abscess). 2. Extension by continuity not lymphatics. 3. High spiking temperatures with chills and shakes. 4. Posterior two-thirds of tongue, then anterior one-third is pushed superiorly and posteriorly in direction. 5. Hard, tense woody cellulitis is palpated. 6. Inability to handle secretions becomes pronounced. 7. Respiratory embarrassment may be acute. 8. Drainage produces a serosanguinous foul discharge, but rarely pus. 9. Commonly found in the debilitated or immunocompromised host.

Sources of Deep Neck Infection and Their Pattern of Spread

Sources Site

Dental infections Submandibular space Lateral pharyngeal space Tonsillar Lateral pharyngeal space Oropharyngeal Lateral pharyngeal space Hypopharyngeal Lateral pharyngeal space.

NB: Petrositis: With the base (roof) of the lateral pharyngeal space in contact. Infection may spread in a caudal direction from a temporal bone primary infection.

Nasal cavity Retropharyngeal space Paranasal sinus Retropharyngeal space Nasopharynx Retropharyngeal space Eustachian tube Retropharyngeal space Soft palate Retropharyngeal space Tongue tip Submental space Skin of chin Submental space Lower lip Submental space.

18 Complications of Deep Neck Infections

1. Airway obstruction. 2. Aspiration. 3. Pneumonia. 4. Mediastinitis (retropharyngeal tract). 5. Peritonitis (prevertebral space tract). 6. Carotid artery rupture. 7. Jugular vein thrombosis. 8. Paralysis of cranial nerves IX, X, XI, XII. 9. Horner's syndrome. 10. Retrograde thrombophlebitis (see no. 7). 11. Emboli: Bacterial endocarditis. 12. Brain abscess (secondary to no. 11). 13. Parotitis. 14. Pericarditis. 15. Spinal cord/vertebrae involvement. 16. Overwhelming sepsis: Shock.

Tonsil

1. Lateral extension of the pharyngeal pouch is largely absorbed (second pharyngeal pouch). Dorsal remnants of the pouch persist to become epithelium of the palatine tonsil. 2. Tonsillar pillars originate from second and third branchial arches. 3. Tonsillar crypts are noted during the third to sixth month of embryologic life. 4. Tonsillar capsule begins to form in the fifth embryologic month.

Palatine Tonsil

1. 20-25 mm length. 2. 15-20 mm width. 3. 12 mm thickness. 4. Average weight of adult tonsil 1-5 g.

Anatomy

Lingual Tonsil

1. Lymphoid follicles vary in number from 30-100; irregular in size and shape. 2. Supplied by lingual branch of external carotid artery. 3. Drained by lingual veins to the internal jugular vein. 4. Gerlach's tonsil: Lymphoid tissue within the lip of the fossa of Rösenmuller. Actually goes into the eustachian tube.

19 Palatine Tonsil Blood Supply

1. Ascending pharyngeal. 2. Ascending palatine. 3. Dorsal lingual. 4. Facial (primary blood supply). 5. Descending palatine.

Palatine Tonsil Venous Drainage

Lingual or pharyngeal vein to internal jugular vein.

Immunology

1. The role of the tonsils remains controversial. 2. Tonsils produce secretory IgA. 3. Tonsils do not produce IgE. 4. Interferon and lymphotoxin have been isolated from tonsil tissue. 5. Infection often results from imbalance between host resistance and normal flora.

The Microbiologic Environment of the Adult Mouth

1. Staphylococci (skin contaminants earliest in newborn). 2. Nonhemolytic streptococci. 3. Lactobacilli. 4. Actinomyces. 5. Leptothrix. 6. Neisseria. 7. Bacteroides. 8. Spirochetes. 9. Micrococci. 10. Virus. a. Myxovirus. b. Adenovirus. c. Picornavirus. d. Coronavirus.

Acute Tonsillitis

1. Beta streptococci. 2. Staphylococci. 3. Streptococcus pneumoniae (Diplococcus pneumoniae). 4. Haemophilus.

20 Differential Diagnosis

1. Diphtheria. 2. Scarlet fever. 3. Vincent's angina. 4. Infectious mononucleosus. 5. Leukemia. 6. Agranulocytosis. 7. Malignancy. 8. Pemphigus.

Complications of Peritonsillar Abscess

1. Airway obstruction. 2. Local venous thrombosis. 3. Phlebitis. 4. Endocarditis. 5. Lateral pharyngeal abscess. 6. Nephritis. 7. Brain abscess. 8. Peritonitis. 9. Dehydration. 10. Perichondritis of thyroid cartilage. 11. Aspiration pneumonia. 12. Hemorrhage.

Tonsillectomy

1. Procedure referred to by Celsus in De Medicina (10 A. D.) 2. Documented surgery by Cague of Rheins (1757) 3. Mortality: 0.5-1:10,000 (reported)

Indications for Tonsillectomy

1. Recurrent episodes of acute/chronic tonsillitis (over six per year) 2. Tonsillitis causing febrile convulsions 3. Diphtheria carrier 4. Hypertrophy involving airway obstruction 5. Hypertrophy involving deglutition problems 6. Possibility of malignancy (biopsy) 7. Peritonsillar abscess.

21 Part 3: Esophagus

Dysphagia

Difficulty in swallowing may be due to oral, pharyngeal, or esophageal dysfunction.

Symptoms May Include

1. Regurgitation 2. Aspiration 3. Pain 4. Tongue mobility dysfunction 5. Substernal fullness 6. Retrosternal fullness 7. Sensation of "stuck" bolus.

Radiologic Findings May Include

1. Dilatation of pyriform sinus or atony. 2. Aspiration of contrast into trachea. 3. Regurgitation of contrast material. 4. Obstruction. 5. Narrowing of the lumen. 6. Absent peristalsis.

Diseases with Dysphagia

1. Inflammatory lesions of the pharynx associated with viral infections. 2. Vincent's angina. 3. Thrush. 4. Tonsillitis (peritonsillar abscess). 5. Retropharyngeal abscess. 6. Plummer-Vinson syndrome. 7. Polio. 8. Pseudobulbar palsy. 9. Cerebrovascular accident (CVA). 10. Acute myelogenes leukemia (AML). 11. Multiple sclerosis (MS). 12. Myasthenia gravis. 13. Polyneuritis. 14. Dermatomyositis. 15. Myotonia congenita. 16. Myotonia dystrophica. 17. Muscular dystrophy. 18. Primary muscular tumors. 19. Primary muscular invasion due to tumor. 20. Zenker's diverticulum. 21. Squamous cell carcinoma.

22 22. Adenocarcinoma. 23. Laryngeal carcinoma. 24. Thyroid mass. 25. Achalasia. 26. Chagas' disease. 27. Scleroderma. 28. Raynaud's phenomenon. 29. Esophageal webs. 30. Esophageal spasm. 31. Psychologic. 32. Schatzki's ring (lower esophageal). 33. Burns. 34. Dysphagia lusoria. 35. Leiomyoma (benign tumors).

Physioanatomical Considerations

1. The esophagus is a mobile structure fixed only at the carotid level. 2. From the teeth to cardia of stomach is 40 cm. 3. The left vagus gradually runs onto anterior surface. 4. The right vagus gradually runs onto posterior surface. 5. The esophagus has no serosal layer. 6. The esophagus has minimal secretory functions. 7. The squamous epithelium is poor for absorption. 8. The oblique angle of entry of the esophagus into the stomach (angle of His) is important. When the angle is lost, reflux occurs. In infants the angle is almost nonexistent; hence, the baby readily refluxes. 9. Reflux is further reduced by the lower esophageal sphincter (LES) which is readily demonstrated manometrically. 10. In most adults the LES extends 1-2 cm below and above the diaphragm. 11. The LES is controlled by the interplay of acetylcholine and gastrin.

Esophageal Symptoms

Odynophagia: Painful swallowing.

A. Heartburn: Vague term usually implying acid reflux (brackish test in back of throat, need to clear throat continually, burning in throat).

1. Peptic esophagitis. 2. Reflux secondary to stomach distension or intra-abdominal pressure increase (pregnancy, bending over, etc). 3. Hiatus hernia.

B. Chest pain.

1. Duration greater than angina. 2. Associated with eating or stress.

23 Aerophagia: Belching is rarely organic. However, in children this may be a source of dysphagia.

Rumination: Rare symptom in which the patient regurgitates one mouthful of food from the stomach into the mouth - chews - and then swallows.

Hypersalivation: Rarely organic.

Lump in Throat: Globus hystericus.

Workup for Esophageal Dysfunction/Pathology

1. Barium swallow with follow-through in stomach. 2. Cine study. NB: A tabler or barium marshmallow can be used more often to highlight esophageal lumen to bring out minor strictures. 3. Cytologic studies: Study of the exfoliated cells in the over 40-year-age group is a valuable diagnostic tool. Saline lavage is the only requirement to obtain cells. 4. Bernstein's test: (Acid perfusion). a. Levine tube aspirates stomach contents and is withdrawn to 35 cm from nostrils. b. Control infusion of 0.9% sodium chloride, 125 drops/min x 15 min. c. Followed by 0.1 N HCl up to 30 min. 5. Acid reflux test. 6. Baloon distention test. 7. Motility studies (manometrics). a. Study three locations: LES, body of esophagus, cricopharyngeus. b. Three conditions in which motility studies have proved valuable include: 1. Achalasia (high pressure). 2. Esophageal spasm (high pressure). 3. Scleroderma (low pressure). 8. Esophagoscopy. a. Rigid: 1. Foreign body. 2. Lesions of cervical esophagus. 3. Obstruction with debris or fluid. 4. Evaluation of stenosis. b. Flexible. 1. Evaluate lesions. 2. Evaluate esophagitis. 3. Evaluate hemorrhage. 4. Obtain biopsy.

24 Congenital Lesions

A. Tracheoesophageal fistulae. 1. 1:1000 live births. 2. Types: a. Dilated upper esophagus ends as a blind pouch with lower esophageal segment attached to the trachea in 87% of the cases. b. A blind upper and lower esophagus without a true fistula to the trachea is present in 8% of cases. c. The "H" deformity is a true fistula without atresia. This occurs in 4%. d. Less than 1% have the upper esophageal segment open directly into the trachea. e. Less than 1% have the upper and lower esophageal segments open independently into the trachea. 3. Sixteen percent of the infants had hydramnios. 4. Clinical features: a. Drooling. b. Coughing. c. Abdominal distension. d. Vomiting. e. Cyanosis and rarely asphyxia. f. Poor feeding. 5. Diagnosis. a. Chest x-ray - right upper lobe pneumonia (aspiration pneumonitis). b. Flat plate of abdomen - marked air filling. c. Radiopaque fluoroscopic evaluation of upper aerodigestive tract. 6. Sixty to eighty percent survive and do well. However if concomitant genitourinary tract or cardiac malformations are present only 22% survive.

B. Dysphagia lusoria. This an uncommon condition of symptomatic compression of the esophagus by the anomalous location of the right subclavian artery (RSA)(Bayford's syndrome). 1. Normally the RSA passes: a. Eighty percent posterior to the esophagus. b. Fifteen percent between the trachea and the esophagus. c. Five percent anterior to the trachea and the esophagus. 2. Clinical features. a. Intermittent dysphagia. b. Weight loss over long period. 3. Diagnosis. a. Barium study (cine). b. Esophageal motility evaluation. c. Upper gastrointestinal endoscopy. d. Angiography. 4. Associated entities. a. Aneurysm. b. Fibrosis secondary to prior surgery around the RSA and/or esophagus. c. Vascular congenital anomaly. The RSA is the most common of arch anomalies and occurs in 0.5-1.8% of the population.

25 d. Aging associated with changes in vessel diameter and thoracic cage dimension changes. e. Atherosclerosis. 5. Treatment. a. Surgery.

C. Chalasia. Occurrence of reflux in infants (by definition there is no hiatus hernia). 1. Clinical features. a. Vomiting or "spitting up" within 3-10 days of birth. b. Belching. c. Weight loss or failure to gain. 2. Diagnostic by radiographic study. 3. Prognosis: Excellent, most children can tolerate feeding while lying on back by 6 weeks.

D. Duplication of the esophagus.

E. Esophageal rings.

F. Esophageal webs.

Esophageal Burn (Corrosive)

A. History. 1. Identify agent: Reference to toxicology screen. 2. Try to determine if material was actually ingested. B. Physical examination. 1. Obvious burn. 2. Dysphagia. 3. Odynophagia. C. Burn suspected. 1. IV fluids. 2. Steroids. 3. Penicillin. 4. NPO. 5. Esophagoscopy within 24 hours: ASAP. 6. Do not induce vomiting. 7. Patient may have pharyngeal-esophageal burn without evidence of burn in oral cavity. D. Findings on esophagoscopy. 1. No burn. a. Follow-up in 2 weeks - asymptomatic - discharge. b. Symptomatic. 1. Barium swallow. 2. Esophagoscopy (?). 2. Burn. a. Do not proceed beyond point of burn.

26 b. Antibiotics. c. Steroids (2-3 weeks taper). d. Serial esophagoscopies done after 2 weeks to decide if burn has healed. e. Dilatation if stricture forms. NB: 1. Early, close observation for airway compromise. 2. Intubation (NG) is controversial. If done it must be within 24 hours and optimally should be under direct visualization. 3. May place string into esophagus to act as guide for esophagoscopy. E. Pathologic Sequence. 1. 0-24 hours: Dusky cyanotic edematous mucosa. 2. 2-5 days: Grey white coat of coagulated protein. Fibroblasts appear. 3. 4-7 days: Slough with demarcation of burn depth. Weakest from days 5-8. 4. 8-12 days: Collagen appears. 5. 6 weeks: Scar formation/stricture evident.

Motor Disturbance in Esophagus

1. Esophageal spasm: Simultaneous repetitive nonperistaltic and often powerful contractions of the esophagus. 2. Presbyesophagus: Associated with age. Mild symptoms to increased dysphagia, substernal pain. 3. Ganglion degeneration: Achalasia, Chagas' disease. 4. Irritant-induced: Gastroesophageal reflux, corrosive irritation. 5. Obstruction of the cardia: Carcinoma, benign stricture. 6. Neuromuscular disorder: Diabetes, alcoholic, AML, dysautonomia. 7. Idiopathic: Often very severe with young patients. 8. Spasm: Symptoms include curling, tertiary contractions, corkscrew esophagus, rosary bead esophagus.

Diagnosis

1. Laboratory studies are normal. 2. Barium swallow may be normal. 3. Cine fluoroscopy. a. Tertiary contractions trap barium in little segments. b. Retrograde displacement of barium into the mouth. 4. Motility studies. a. Spontaneous waves not preceded by a swallow. b. Three to five repetitive waves that follow each other after one swallow. c. Simultaneous high-peaked waves occurring in all three leads.

Cricopharyngeal Dysphagia

1. Presumably analogous to achalasia in the failure of a sphincter to relax. 2. Diseases. a. Idiopathic. b. Polio.

27 c. Thyrotoxic myopathy. d. Left or right recurrent nerve paralysis. e. S/P pharyngectomy with hypertrophied cricopharyngeus muscle. 3. Diagnosis. a. Barium swallow. b. Cine studies. c. Manometrics.

Achalasia

A. Megaesophagus 1. A disorder (cardiospasm) of esophageal motility characterized primarily by failure of the LES to relax normally. 2. Diseases. a. Status postvagotomy. b. Psychologic. c. Chagas' disease. d. Neutrotrophic virus. e. Destruction of myenteric plexus. f. Drugs. g. Gastroesophageal tumor invasion. h. Hereditary component (?).

Table 16-1. Differential Comparison of Esophageal Spasm and Achalasia&

Symptoms Esophageal Spasm Achalasia

Dysphagia Midsternum Xyphoid or suprasternal notch Pain Common Rare Belching Common Rare Weight loss Rare Common Emotional Common Common

Motility

Waves Simultaneous Weak, ineffective LES (relax) Present Absent Methacholine Slight Hyperactive (Mechlolyl stimulation)

Radiographic

Esophageal contraction Active Weak Esophageal emptying Efficient Poor

28 Response to Therapy

Bougienage Good Fair Pneumostatic Dilatation Not indicated Good Surgical Rx Long myotomy Low cardioesophageal myotomy.

&NB: Both achalasia and spasm can mimic angina pectoris.

Table 16-1 compares the observations that differentiate between spasm and achalasia.

Structural Disorders of the Esophagus

A. Four classic anatomic compression locations. 1. Cricoid. 2. Left mainstem bronchus. 3. Diaphragm. 4. Aorta. B. Three neck compression sites include: 1. Thyroid. 2. Parathyroid. 3. Thymus. NB: The cervical spine may impinge especially in the elderly. C. In the chest, compression may come from: 1. Large nodes (associated with histoplasmosis, sarcoid, tuberculosis). 2. Mediastinal tumors. 3. Duplication cysts. 4. Enlargement of the heart especially secondary to mitral valve. 5. Aneurysms. 6. Poststenotic dilatation secondary to coarctation of the aorta. 7. Massive enlargement of the liver.

Diverticulum

A diverticulum is generally due to anatomic weakness including:

1. Killian's dehiscence: Between the cricopharyngeus and thyropharyngeus muscles. 2. Lamier-Hackeman space: Between the circular and longitudinal fibers of the esophagus. 3. Killian-Jameison space: Between the cricopharyngeus and the circular fibers of the esophagus.

A. Zenker's.

This diverticulum is related to a developmental weakness of the muscular coat of the posterior portion of the pharynx between the oblique fibers of the inferior constrictor muscle and the horizontal fibers of the cricopharyngeus. It represents 80% of all diverticula.

29 1. Symptoms. a. Delayed regurgitation (as late as 24 hours). b. Aspiration. c. Dysphagia (a late symptom). d. Foul breath. e. Bleeding and perforation are very rare. f. Gurgling or fluid slosh. 2. Diagnosis. a. Barium swallow. b. Esophagoscopy. 3. Treatment. a. Excision of sac and cricopharyngeal myotomy (Dohlman's procedure is not recommended). B. Midesophageal. 1. Most commonly at the level of the pulmonary hilum. 2. Accounts for 7% of all diverticula. C. Epiphrenic. 1. Lies just above the cardioesophageal junction. 2. Often on the right side. 3. Very minimal symptoms. 4. Accounts for 13% of all diverticula.

Pathophysiology

A. Pulsion diverticula often are seen concomitant with other esophageal disorders such as spasm and hiatal hernia. As the diverticulum enlarges, its sac lies lower in the neck so that it traps food and liquids. B. Traction diverticula are pulled out by an inflammatory process adjacent to the esophagus. They usually occur in the midesophageal area at T-4, T-5 region where the esophagus lies closest to the nodes of the tracheobronchial area. They tend to be on the left side and are rare. NB: Traction diverticula are associated commonly with tuberculosis. C. Symptoms from diverticula of the esophagus do not always intensify (25% get worse). D. Complications include: 1. Aspiration pneumonia. 2. Bronchoesophageal fistula. 3. Bleeding. 4. Abscess. NB: Intraluminal diverticulosis of the esophagus is associated with Candida albicans (1-3 mm size; multiple).

Hiatal Hernia

The presence in the chest, above the diaphragm, of a portion of a stomach that has passed up through the normal esophageal hiatus is referred to as a hiatal hernia.

30 1. Incidence: 0.8-29.6%. 2. Incidence is age related: under 40, 9%; over 70, 69%. 3. Found in women more frequently than men. 4. Loss of muscle tone is a common factor in pathogenesis. 5. Associated disease or pathologic processes include: a. Pregnancy. b. Obesity. c. Tight girdles. d. Ascites. e. Esophageal tumors. f. Exercise tension. g. Prolonged nasogastric tube placement. h. Constipation. i. Intra-abdominal tumors. j. Kyphoscoliosis (high association). k. Status post-Heller's procedure. l. Status post partial gastrectomy. m. Trauma. 6. Types. a. Paraesophageal (rare). b. Sliding (common). c. Congenital short esophagus. 7. Symptoms. a. Reflux esophagitis (postprandial). b. Spasm. c. Dysphagia. d. Bleeding. e. Vomiting (incarceration). f. Aspiration. 8. Sandifer's Syndrome. Bizarre contortions of the neck, apparently in an effort to reduce discomfort in the lower esophageal region, have been reported as symptoms of unrecognized hiatus hernia in some children. 9. Plummer-Vinson syndrome often is associated with hiatus hernia. The sudden onset of projectile vomiting, severe pain or spasm (cramps), and complete aphagia heralds acute incarcertation and is a surgical emergency. NB: The physical examination of a patient with a hiatus hernia is often negative except for chest (anterior and posterior) wall auscultation revealing borborygmi.

Diagnosis

1. Laboratory: Occult blood in stool. 2. Hypochromic microcytic anemia. 3. Chest x-ray: Air shadow behind heart. 4. Barium swallow. 5. Esophagoscopy is not indicated unless additional information is desired regarding other possible pathology. On examination the gastroesophageal rosette is at 34-38 cm instead of the usual 40 cm.

31 Saint's Triad: Gallstones, diverticular colonic disease, hiatus hernia. 10. Dermatomyositis. A diffuse inflammatory disorder of striated muscle which causes symmetrical weakness and muscular atrophy. a. Stomatitis is present. b. Weakness of facial muscles may hamper eating. c. Peristalsis is diminished and poorly coordinated. d. The esophagus may be dilated. e. Manometric evaluation: 1) Decreased upper esophageal sphincter pressure. 2) Low multiple contractions of the pharynx and the esophagus. f. In contrast to scleroderma, the striated muscles of the hypopharynx and esophagus are involved. g. Hiatus hernia and the reflex esophagitis commonly associated with scleroderma are absent. 11. Scleroderma (progressive systemic sclerosis). a. Sixty percent of the patients have symptomatic dysphagia. b. Reflux and esophagitis is not uncommon. c. Aperistalsis of the lower two-thirds of the esophagus is present. d. Marked decrease in lower esophageal sphincter pressure is demonstrated by manometrics. e. Normal peristalsis can be shown in the upper esophagus. f. Barium studies show: Aperistalsis, dilatation, and gastroesophageal reflux.

NB: Both scleroderma and achalasia show distension in the supine position by barium study. However, when the patient is standing an air/fluid level is often seen in achalasia while free passage to the stomach is noted in the patient with scleroderma.

Lower Esophageal Ring (Schatzki's Ring)

This is a concentric ring or a weblike narrowing occurring at the junction of the esophageal and gastric mucosa. A. Incidence. 1. Is 6-14% of routine barium swallows, but only one-third are symptomatic. 2. Symptoms are rare under 40 years of age. B. Pathology. 1. Mucosal ring (common): B ring. 2. Muscular ring (rare): A ring. Marks the interior esophageal sphincter of Leriche. 3. Dyphagia is likely to present when the ring reduces the esophageal lumen to less than 13 mm in diameter. C. Symptoms. 1. Intermittent dysphagia is the salient feature. The most characteristic feature is the patient's ability to bring up food or to force it down when stuck, and the continue to ear. 2. Absence of heartburn. D. Diagnosis. 1. Laboratory studies are of no value. 2. Manometry is of no value. 3. Cine barium swallow (patient should be recumbent for study).

32 4. Flexible fiberoptic esophagoscopy. 5. The ring is usually noted 4-5.5 cm above the apparend diaphragmatic shadow, above the pinched-off segment of barium, moving upward away from the diaphragm as the segment below the ring distends with barium.

Esophageal Webs

A web is an aberrant structure consisting of squamous mucosa located anywhere along the esophagus.

1. Dysphagia due to a web is slowly progressing. 2. Cervical webs are associated with iron deficiency. 3. There is a significant association between webs and hypopharyngeal carcinoma (see Plummer-Vinson syndrome). 4. Webs usually are noted on the anterior wall of the esophagus and require better lateral or oblique films for demonstration. A ring on the other hand is best noted when the esophagus is distended. 5. Webs are asymmetric whereas rings are symmetric. E. Differential. 1. Plummer-Vinson syndrome. 2. Carcinoma. 3. Achalasia. 4. Neuroma. 5. Leiomyoma. 6. Ring of cartilaginous tissue. F. Therapy. 1. Bougienage. 2. Inflatable bag. 3. Surgical (incision of web)(rare).

Boerhaave's Syndrome

Boerhaave's syndrome results from a tear through all three layers of the wall of the esophagus just above the diaphragm produced by a sudden increase in esophageal pressure.

A. Occurrence. 1. Rare in both adults and children. B. Pathology. 1. Short, linear, 1 to 4 cm long tear. 2. Located on the left side 90% of the time. 3. Five times more frequent in men than women. C. Clinical picture. 1. Vomiting. 2. Abrupt, sharp (knifelike) pain in epigastrium. 3. Radiation of pain to left shoulder. 4. "Something gives way inside". 5. Shock. 6. Respiratory difficulty.

33 7. Occasional hoarseness. 8. Subcutaneous emphysema. 10. Diagnosis. 1. History and physical (note subcutaneous emphysema). 2. Chest x-ray (left effusion). a. If tapped check for amylase to rule out pancreatitis. b. Culture and Gram stain. 3. Barium should not be used for contrast study, Hypaque is more benign and does not cause granulomas. (Some radiologists feel barium is best and not dangerous.) E. Differential. 1. Myocardial infarction. 2. Pulmonary embolus. 3. Ruptured gastric ulcer. 4. Ruptured duodenal ulcer. 5. Acute pancreatitis. 6. Aortic aneurysm rupture. 7. Mallory-Weiss syndrome. 8. Perforation of a Barrett's ulcer. F. Treatment. 1. Thoracotomy and mediastinum drainage. 2. Systemic antibiotics.

Mallory-Weiss Syndrome

This syndrome is manifest by bleeding from the cardia of the stomach (lacerations).

1. Massive upper gastrointestinal bleeding. 2. Seen most often in alcoholics. 3. Seen most often in males over 40.

Iatrogenic Perforation

This complication is largely due to an inexperienced endoscopist.

A. Clinical picture. 1. Sore throat immediately after procedure. 2. Tachycardia out of proportion to fever. 3. Temperature spike, chills. 4. Subcutaneous emphysema. B. Chest x-ray. 1. Effusion. 2. Widened mediastinum. 3. Maybe pneumoperitonitics. C. Therapy. 1. Antibiotics. 2. Drainage. 3. Closure.

34 Foreign Bodies in Esophagus

History and physical examination. Foreign bodies commonly lodge at or just below the criopharyngeus.

A. Evaluation. 1. Auscultation. 2. Barium swallow is best avoided since, in a symptomatic patient, treatment will be instituted regardless, and if the patient needs surgery barium will obscure the field. Furthermore in awake intubations the patient may aspirate. 3. Occasionally a cotton pledget or marshmallow coater with barium may of assistance in localizing a bone if there is a question of a foreign body. B. Treatment. 1. Assure the patient that his life is not in danger. 2. Never attempt to push a foreign body into the stomach by bougienage. 3. Attempt relaxation with: a. Meperidine (Demerol)(mg/kg) and atropine. b. Amyl nitrite (young healthy patients only). c. Diazepam (Valium). d. Glucagon (1 mg/amp) IV, followed by water; wait 20 minutes and repeat. 4. The use of papain to dissolve meat that is stuck in the esophagus is contraindicated, and its use is currently not recommended although products such as meat tenderizer have been reported to be successful. A tendency toward perforation is the feared sequela. 5. Esophagoscopy and removal. a. Positioning of the patient is 90% of the knack. b. Many instruments designed for foreign body removal are sharp and by themselves dangerous in inexperienced hands. c. Follow Jackson's dictum for pointed objects "don't look for the foreign body, look for its point". 4. Never use force - bougienage is not indicated. 5. Perhaps most important is to have complete and safe control of the airway before beginning any manipulation.

Congenital Diaphragmatic Hernias

1. Pleuroperitoneal (Bochdalek's): Posterior. 2. Retrosternal (Morgagni's): Anterior.

Inflammatory Disorders

Plummer-Vinson Syndrome (Patterson Kelly)(Sideropenic Dysphagia)

1. Incidence: 90% female, 10% male. 2. Predominant occurrence in Northern hemisphere. 3. Hypothyroidism is commonly associated.

35 A. Clinical features.

1. Esophageal webs. 2. Iron deficiency anemia. 3. Dysphagia. 4. Lower esophagus is usually normal. 5. Tongue and oropharynx are usually atrophic. 6. Painless. However, a choking sensation is felt. 7. Ninety percent of the patients have absence of teeth. 8. Fingernails: Spoonshaped. 9. Achlorhydria (30-40%). 10. Pernicious anemia. 11. Atrophic gastritis (40%). 12. Multiple circulatory autoantibodies (50%). 13. Splenomegaly may be present. 14. Cheilosis is notable. B. Pathology. 1. The esophageal and pharyngeal mucosa may be atrophic at autopsy. 2. Striated muscle at the upper end of the esophagus is often atrophic and replaced by cartilaginous tissue. 3. The lower portion of the esophagus is normal. 4. Biopsy of the associated webs reveals only chronic inflammation with normal squamous epithelium. C. Diagnosis. 1. Cinefluoroscope is essential. 2. Esophagoscopy. a. A web is viewed as a smooth, grey, diaphragmatic opening with eccentric lumen. D. Treatment. 1. Treat underlying anemia. 2. Dilate. 3. NB: Over 50% of women with PV syndrome develop carcinoma of the upper gastrointestinal tract or hypopharynx.

Esophagitis

A. Diagnosis. 1. Sphincter incompetence. a. pH monitoring. b. Radiographic scanning (cine studies). c. Esophageal manometry. 2. Esophagitis by acid infusion test (Bernstein's test). 3. Esophagoscopy. 4. Esophageal biopsy. B. Treatment. 1. Position. 2. Correct underlying problem (nasogastric tube, hiatus hernia, etc). 3. Cimetidine (300 mg PO every 4 hours, PC and HS). 4. Antacids.

36 5. Surgical closure of hiatus hernia/vagotomy. 6. Dilatation of stricture.

Barrett's Esophagus

The lower portion of the esophagus is lined with columnar (gastric) rather than squamous epithelium.

Barrett's Ulcer

The term Barrett's ulcer is used to describe the sharply punched out, deep peptic ulcer occurring in such epithelium.

Delahanty's Syndrome

Hoarseness, chronic laryngitis, and arytenoid inflammation due to acid spillover.

Moncreiff's Syndrome

Hiatus hernia associated with sucrosuria and mental retardation.

Mendelsohn's Syndrome

Aspiration pneumonia from gastric reflux (70% R, 30% L).

Sandifer's Syndrome

Neoplasms

Benign Tumor

1. Most common is leiomyoma. 2. Followed by: a. Fibroma. b. Lipoma. c. Hemangioma. d. Neurofibroma.

Carcinoma

1. Four percent of cancer deaths. 2. Male preponderance 5:1. 3. No genetic predisposition. 4. Associated with chronic alcohol use and tobacco. a. Twenty-five percent more common in heavy drinkers. 5. May increase risk: a. Lye stricture. b. Plummer-Vinson syndrome.

37 c. Esophagitis. 6. Location. a. Forty to fifty percent occur in the lower one-third. b. Thirty to forty percent occur in the middle one-third. c. Ten to thirty percent occur in the upper one-third. 7. Other malignant neoplasms include: a. Sarcoma. b. Leiomyosarcoma. c. Fibrosarcoma.

Esophagostomy

1. Advantages. a. Tube may be left out. b. Easy skin care. c. Feeding in upright position. d. Less risk of postoperative ileus/atelectasis. 2. Disadvantages. a. Cellulitis. b. Infection. c. Hemorrhage. d. Recurrent nerve injury. e. Aspiration pneumonia. 3. Contraindications. a. Superior vena cava syndrome. b. Complete esophageal obstruction. c. Anterior laryngo-pharyngoscopy or neck carcinoma. d. Irradiation to neck (greater than 5000 rads). e. Severe gastric reflux. f. Uncontrolled aspiration.

38 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 17: Salivary Glands

There are essentially three paired salivary glands: the parotid glands, submandibular glands, and the sublingual glands. In addition, the minor salivary glands, or accessory glands are present in the oral cavity. They can be split into 3 main categories: the anterolingual glands, the serous glands of Von Ebner, the lingual buccolabial and palatal glands.

Parotid Glands

Each parotid gland is pyramidal in shape and weighs approximately 25 g. The deep cervical fascia splits to enclose the parotid gland. The gland is serous in nature, with a few scattered mucous acini. Anatomically the gland can be split into two lobes: the larger superficial lobe and the deep lobe.

The superficial lobe lies wedged between the mastoid process and the posterior border of the mandible, extending forward over the masseter for a variable distance. Its anterior border is convex forward and from it emerges the parotid duct and the five divisions of the facial nerve. Posteriorly, the gland is related to the mandibular joint, the osseous and cartilagenous portions of the external auditory canal, the mastoid process, and sternomastoid muscle.

The deep lobe of the gland, a narrow edge of the wedge-shaped gland, lies in contact with the internal jugular vein. The gland contains the pes anserinus of the facial nerv within the substance of its superficial lobe. More deeply lies the retromandibular vein and deepest of all, the external carotid artery. The parotid duct passes forward across the masseter muscle, turns around its anterior border to pierce the buccinator. The duct opens on the mucous membrane of the cheek, opposite the second upper molar tooth. The bed of the parotid consists of the posterior belly of the digastric muscle, the styloid process, and the stylohyoid muscles. Deep to them are the internal jugular vein, crossed by the accessory nerve as it lies on the accessory nerve as it lies on the lateral mass of the atlas; further forward is the internal carotid artery. The blood supply is from branches of the external carotid artery, and the venous drainage is via the retromandibular vein.

Nerve Supply

The nerve supply is secretomotor fibers arising from cell bodies in the otic ganglion. These reach the gland by hitchhiking along the auriculotemporal nerve. The preganglionic fibers arise from cell bodies in the inferior salivatory nucleus in the medulla and travel by way of the glossopharyngeal nerve. They then travel by the tympanic branch and the tympanic plexus, and subsequently by the lesser superficial petrosal nerve to the otic ganglion. The sympathetic fibers reach the gland from the superior cervical ganglion by way of the plexus on the external carotid and middle meningeal arteries.

1 Submandibular Gland

This salivary gland, which is two-thirds serous, lies between the floor and the roof of the submandibular fossa, partly under the cover of the mandible. Its contact with the bone is responsible for the smooth enlarged concavity that lies below the mylohyoid line opposite the bicuspid and molar teeth. The gland, which is the size of a walnut, becomes narrow posteriorly and curves around the free posterior border of the mylohyoid muscle. A smaller deep part of the gland lies on the floor of the mouth between the mandible and the side of the tongue. The main duct within the gland thus curves around the posterior border of the mylohyoid muscle. The blood supply is via the main facial artery, and venous drainage is into the common facial vein.

Nerve Supply

Secretomotor fibers to the gland have their cell bodies in the submandibular ganglion, the preganglionic fibers pass through cell bodies in the superior salivatory nucleus in the pons by way of the nervus intermedius and travel with the facial nerve as far as the stylomastoid canal. They leave the facial nerve in the chorda tympani nerve, the company with the taste fibers, to the anterior two-thirds of the tongue, pass along the lateral wall of the middle ear, and leave the skull through the petrotympanic fissure. They join the lingual nerve from behind, a full inch below the base of the scalp.

Sublingual Glands

The sublingual glands are the smallest of the major glands. Each is the size and shape of an almond and weighs approximately 3-4 g. Each gland lies immediately beneath the oral mucous membrane, raising a fold beside the tongue. Below the gland is the mylohyoid muscle, laterally is the mandible and medially is the genioglossus muscle.

Histology and Ultrastructure

The salivary glands are described as being lobular and racemose, i.e. lobes or lobules having the separate appearance of a bunch of grapes. These lobules are the functional units of the glands. Each is built up from acini, intercalated ducts, and striated ducts, the stalks. Each acinus gives rise to an intercalated duct and these join to form larger ducts. Joining of ducts occurs throughout the intercalated and striated duct regions, until each lobule gives rise to a lobular excretory duct. Finally, after many further junctions of ducts, the glands' secretion passes out through the main duct (see Fig. 17.1). An acinus consists of a spherical group of cells, each polygonal in section, enclosed by a basement membrane and themselves enclosing a space whcih is the beginning of the duct system. The acinar cells are classified histologically into two types, according to their appearance after staining with haematoxylin and eosin. Predominantly pink-staining cells with large granules are found in the acini of the sublingual and the submandibular gland, but rarely in the parotid gland. Since their staining properties resemble those of other cells elsewhere which produce mucoid substances, and since the secretion of sublingual and submandibular glands is viscous and rich in protein- carbohydrate complexes, they have been referred to as mucous cells. Cells which stained pale blue and contained much smaller granules than those in the mucous cells make up most of the acini of the parotid gland and the glands of Von Ebner. Similar cells are found in the

2 anterior lingual glands and the submandibular glands, where they are raised as a layer on the outer surface of acini, composed of the mucous-type cells. In these glands they represent, in section, a crescent shape or demilune. In the parotid, the secretion of this type of cell can reach the acinus directly, but in other glands it must pass through fine canaliculi between the mucous cells. As these cells are the dominant ones in the parotid gland, and produce a secretion much less viscid and more serous than the secretions of other glands, they are termed serous cells. Despite this histologic distinction these cells do produce mucoproteins. However, their characteristic product in man is the starch-splitting enzyme, amylase. The cells of the intercalated duct are small cuboidal cells with large nuclei and few organelles. The intercalated duct is relatively short and the small cells soon give way to large cuboidal cells. From the striated duct there is an abrupt transition to the excretory ducts with a two-layered epithelium, the superficial layer columnar, and the depp layer flat cuboidal. Finally, near the termination of the main ducts there is another abrupt transition to a multilayered stratified squamous epithelium like that of the oral mucosa. In addition to these cells another cell is found in the major salivary glands. This is the myoepithelial cell, a cell with a regular orientation of fibers like that of smooth muscle. It is believed that the contraction of these fibers causes the expulsion of formed saliva.

Stimulus to Secretion

The stimulus to secretion can be classified the three separate categories: local, interorgan, and psychic stimuli.

Psychic Stimuli

Stimuli to sense organs of the head and specifically the mouth, often are associated with food intake. The stimulation of sight or hearing causes salivation only by a condition reflex, i.e. the sight of food or the sound of cooking, while the hearing or a verbal description of food is a psychic stimulus rather than a local or direct stimulus.

Local Stimuli

Stimuli upon the sensory organs of the head often are termed cephalic. The term normally also includes psychic stimuli. In considering stimuli causing secretion of saliva, local stimuli may be taken as the cephalic stimuli with the exclusion of the psychic or condition stimuli. Local stimuli include:

Smell

Olfactory irritants cause a direct salivary reflex. It is uncertain, however, whether or not nonirritating olfactory stimuli also can do so, or whether the salivary response to nonirritating smell is a conditioned reflex.

Taste

There is an increase in the salivary flow whenever the sense of taste is stimulated. Acid stimuli are the most effective in stimulating salivary flow, sweet and salt are less so, and bitter least of all.

3 Touch and Irritation of the Oral Mucosa

The proporioceptive impulses arise from the masseter muscles, the temporomandibular joint, and impulses from pressure sensors in peridontal membranes of the teeth. There is evidence that unilateral stimulation of smell, taste, touch, or proprioceptive sensors cause predominantly unilateral secretion of saliva.

Interorgan Stimuli

Inter-organ stimuli are not particularly apparent in the control of salivary secretion. Irritation of the esophagus is said to cause reflex salivation.

Composition of Saliva

Saliva contains inorganic ions and organic molecules of various sizes dissolved in water. More than 99% of saliva is water. In mixed saliva the total organic content amounts to a little over 5 g/L and the total inorganic to about half of this.

Organic Compounds

Protein

The total protein content of mixed saliva is around 2.2 g/L. At higher flow rates the amount of protein increases. Analysis of saliva collected over a variety of conditions give a protein concentration of 2.3 g/L. The amount of protein in saliva depends on the flow rate. In general, the protein concentration increases with increased flow rate. The proteins of saliva have been classified as serum proteins, proteins of glandular origin, including glycoproteins and enzymes, and blood group substances. In all, more than 20 proteins have been separated in analysis of saliva.

Serum Protein

Amylases of saliva by electrophoresis and immunochemical methods have demonstrated seven or eight proteins which show antigenic properties similar to those of blood proteins. These include serum albumin and gamma globulin with beta globulins. The total proportion of serum proteins may be as much as 20%. Gamma globulins in saliva have interested dental research workes, since they may include antibodies against oral disease. No correlation has been shown between susceptibility to dental caries and gamma globulin concentrations in saliva.

Proteins Similar to Those in Serum

The question of the origin of gamma globulins and of serum albumin already has been discussed. The number of proteins similar to action to some of the blood-clotting factors has been described in saliva: proactivator, Christmas factor, antihemophiliac globulin, and a platelet factor. All have their analogues in saliva.

4 Enzymes

Amylase

The characteristic enzyme of saliva is an alpha-amylase capable of splitting cooked starch down to maltose. It has an optimum pH of 6.8 and needs chloride ions present for full activity.

Lysozyme

This enzyme which splits the carbohydrate of the cell walls of certain bacteria is present in most body secretions. In parotid saliva it comprises about 10% of the total protein. Its concentration is high in submaxillary gland saliva.

Phospholipase, Cholinesterase and Ribonuclease

These are present in similar concentrations in plasma and saliva.

Lipase

A specific lipase has been described in saliva.

Peroxidase

An antibacterial peroxidase system is found in saliva.

Other Enzymes

In mixed saliva an enormous range of enzymes is present. These enzymes include those produced in the glands and also from plasma.

Kallikrein

This enzyme which produces bradykinin by splitting a serum beta globulin is produced in the salivary glands. Most of the early work on bradykinin was carried out with saliva- serum mixtures. It is thought that this enzyme passes back into the gland to reach the blood vessel, causing the functional dilatation necessary to supply the totally secreting gland with sufficient blood flow.

Mucoproteins and Glycoproteins

Most salivary proteins contain a large portion of carbohydrate in their molecules. In parotid saliva about 35% of the total protein contains appreciable amounts of carbohydrates. These carbohydrate-proteins contain about 75% protein, with proline, glycine, and glutamic acid as the major amino acids.

5 Blood Group Substance

Blood group substance are carbohydrate-protein complexes present on the cell walls of the red blood cells. Normally the red cells are characterized by the presence or absence of two antigens, A and B, which differ in their terminal sugar chains. About 80% of the population exhibit, in their tissue fluids and secretions, the antigens corresponding to their blood group, or the glycoprotein H substance which lacks the terminal polysaccharide genes. These substances are secreted in the submandibular and sublingual salivas, but not in parotid saliva. The only blood group antigens which have been described in saliva are those of the Lewis group.

Hormones

A substance having hormonal activity has been isolated as a protein compound of the parotid saliva termed parotin. It is said to maintain serum calcium levels and promote calcification.

Inorganic Compounds

The total inorganic content of saliva is about 2.5 g/L.

Sodium

Sodium is the most abundant ion in extracellular fluids and appears in the secretion at 140-150 microm/L.

Potassium

Extracellular fluids normally contain low concentrations of potassium. However, all parts of the salivary and ductal system, except for the terminal duct, appear to transport potassium into the secretion at flor rates above 0.2 mL/min. The potassium concentration of the saliva stays constant at around 20 micromol/L.

Chloride

Chloride is the major anion of extracellular fluids. Its concentration in the secretion mirrors that in the plasma at around 100 mEq/L.

Bicarbonate

Bicarbonate appears to be in very low concentration in resting saliva. As the gland cells become active, their carbon dioxide production, due to metabolism, increases the enzyme carbonic anhydrase, made from the formation of carbonic acid and bicarbonate, is secreted into the saliva. The concentration of bicarbonate increases with the flow rate to reach as high as 60 mEq/L.

6 Hydrogen Ions

The pH of saliva is low in the resting secretions but rises as high as 8 in fast-flowing saliva. This is largely due to the bicarbonate content.

Iodine

The salivary gland actually transports iodine so the concentration is higher in saliva than in plasma. The concentration increases with flow rate.

Fluoride

Saliva contains 0.1 ppm or 5.2 micromol/L of fluoride. This concentration is of the same order of magnitude as that in plasma.

Thiocyanate

Thiocyanate is present in saliva in a higher concentration than in serum. It has been suggested that the salivary glands have an excretory function for this ion. There is some evidence that the concentration is higher in the saliva of cigarette smokers.

Calcium

The calcium content of the submandibular saliva is approximately twice that of parotid saliva. The concentration is high in resting saliva. Levels in submandibular saliva may exceed blood levels. This probably is due to active secretion of calcium. As the flow rate rises above resting rates, the concentration at first falls, but in fast-flowing saliva the concentration rises.

Phosphate

Almost all the phosphate present in saliva is inorganic.

Factors Affecting the Concentration of Salivary Constituents

Flow Rate in Individual Salivary Glands

These can be briefly summarized as follows:

1. Substances whose concentration increase with flow rate: total protein, amylase, sodium bicarbonate. 2. Substances whose concentration does not change with changes in flow rate: potassium, possibly fluoride. 3. Substances whose concentration falls as the flow rate increases: phosphate, urea, amino acids, uric acid, ammonia, serum albumin, magnesium. 4. Substances whose concentration falls at first but rises as flow rate increases: chloride, calcium, protein, bicarbonate.

7 Maintenance of Stimulus

Maintenance of stimulation to the glands for periods briefer than 3 minutes results in their reduced concentration of many components. After an initial fall, concentrations of calcium bicarbonate and protein again begin to rise. Sodium and iodine concentrations are not affected by duration of stimulation. After the first few minutes, phosphate and potassium concentrations fall and then remain steady.

Nature of Stimulus

Protein concentration in the parotid and submandibular saliva may vary with the stimulating agent. Variations in composition of whole saliva may arise from different proportions of the major secretions, either due to the greater maximum flow from the larger parotid glands or difference in stimuli susceptibility among the glands.

Time of Day

Circadian rhythms have been reported in the concentrations of protein, amylase, potassium, chloride, phosphate, organic phosphae, cortisone, and thiocyanate. In general, protein concentrations seem to be high in the afternoon and related to mealtimes. Sodium and chloride concentrations are high in the early hours of the morning. Plasma concentrations: The concentration in salivary urea, uric acid, amino acids, sodium, and chloride are related to plasma concentrations.

Hormonal Effects

Antidiuretic Hormone

The water content of saliva is affected by secretion of antidiuretic hormone. This appears to affect the permeability of striated duct cells and permits more water to be reabsorbed.

Aldosterone

Transportation of sodium and potassium in striated ducts is controlled by aldosterone, causing increased reabsorption of sodium.

Systemic Hormones

Hypophysectomy reduces secretion in animals. Testosterone and thyroxine both increase salivation. In pregnancy salivation increases, and at the menopause there is often xerostomia.

Local Hormones

Bradykinin and its precursor kallidin stimulate secretion by increased blood flow.

8 Influence of Diet

It is known that the size and activity of salivary glands are influenced by the degree of stimulation, either mechanical or gustatory, to which they are subjected. Increases in phosphate or calcium in the diet do not appear to affect salivary levels.

Functions of Saliva

The function of saliva may be classified as follows:

Protective Function

As a Fluid:

Saliva acts as a protective medium for the cells of the mucous membrane, preventing them from drying. The oral mucosal cells differ from squamous epithelium elsewhere, being much less protected against evaporation. Production of saliva in large quantities allows it to act as a mechanical medium, washing away particles from around the teeth.

As a Lubricant:

The lubricant action of the water of saliva is enhanced by its protein and mucoprotein content. The mouth is subjected to abrasive food substances and this abrasive action is moderated by the covering of the tissues by a viscous solution. This lubricating fluid assists in the formation of a food bolus suitable for swallowing. It is also necessary for adjustments of air flow to produce speech.

As a Solution with Antibacterial Activity:

Saliva has several components which afford protection against bacterial attack. The cells of saliva include leukocytes which may contribute to its protective activity against bacteria and the substances synthesized by them. The bacteria normally present in saliva establishes a close, interwoven ecology that foreign invading bacteria are unable to penetrate. Lysozyme is specifically active against bacteria whose cell walls contain muramic acid. The antibodies of saliva, the gamma globulins, are able to react with the antigens in the presence of some oral bacteria. An antibacterial system consisting of the globulin and thiocyanate ions has been described. Peroxidases also act as antibacterial enzymes.

As an Accelerator of Blood Clotting

A number of blood-clotting factors have already been described.

As a Factor in Maturation of Teeth

The tooth surfaces are composed of apatite crystals which can acquire ions from, or exchange ions with, saliva. The susceptibility of newly erupted teeth to solution in acid is much greater than that with which have been exposed to saliva for some time.

9 As a Protection to Tooth Decay/Solution in Acid

Saliva is effectively supersaturated with respect to the apatite of dental enamel. This means that only if the pH drops markedly will apatite begin to dissolve. Furthermore, saliva contains the buffer bicarbonate.

Digestive Functions

Saliva has little digestive function in the mouth, its role as a lubricant being much more important. Amylase is the main digestive enzyme.

Water Balance

The digestive secretions, including saliva, consist largely of water. This water, about 8 L/day in all, passes into the lumen of the digestive tract, which is functionally outside the body. It must therefore be reabsorbed. If this amount of water is lost, either by vomiting or diarrhea, the total body water will be depleted. Loss of water can occur due to panting or hyperpnea. Reduction in extracellular fluid volume leads to reduction in salivary volume.

Excretory Function

Saliva has been described as an excretory route for several blood components. Since saliva and its constituents usually are reabsorbed in the lower part of the gut, it would not appear to be a very efficient excretory route. Urea, uric acid, and ammonia pass into saliva. Their small size enables them to cross the membranes of the cells of the salivary glands. Thiocyanate also has been described as an excreted substance. Heavy metals including lead, mercury, and bismuth appear in saliva if blood levels are raised.

Solvent Function

Saliva dissolves foodstuffs and aids in their comminution and digestion. In addition, solubilization is essential for perception of taste.

Iodine Balance

Secretion of iodine into saliva has already been mentioned.

The Importance of Saliva in Relation to Oral Disease

Many studies have been performed on saliva with the object of linking its composition or changes in composition with oral disease, particularly dental caries. The important interactions of saliva may be summarized as its antibacterial activity, its role in plaque formation, the equilibrium between saliva and plaque constituents, and its possible effects on dental calculus formation.

Antibacterial Activity

This has already been discussed as a protective function of saliva.

10 Formation of Dental Plaque

The pellicle formed on clean tooth surfaces exposed to saliva is similar in composition to the glycoproteins of saliva. Saliva contains a glycoprotein which binds to apatite and therefore to the dental enamel. Saliva contains proteins which spontaneously may precipitate out of solutions or on drying. The enzyme neuraminidase is found in saliva. It is capable of changing the properties of glycoproteins by splitting off sialic acid end groups. The changed glycoproteins may precipitate on the tooth surfaces. Some salivary bacteria are capable of producing sticky polysaccharidic coats which cause them to aggregate and stick to surfaces. The layer of bacteria could then function as an initial layer of plaque.

Salivary Gland Pathology

Classification

Congenital Disease.

1. Dermoid cysts. 2. First cleft anomalies (type 1, type 2). 3. Branchial pouch.

Traumatic.

Laceration.

Inflammatory Disease.

Acute

1. Viral. 2. Bacterial (acute suppurative disease). 3. Allergic. 4. Drugs.

Chronic

1. Obstructive (calculi, stricture, sialadenitis, sialectasis). 2. Nonobstructive (postmumps sialectasis, nonspecific sialadenitis). 3. Tuberculosis, actinomycosis. 4. Benign lymphoepithelial disease (sialectasis). 5. Drugs (iodine, lead, copper).

11 Metabolic

Benign Hypertrophy

1. Hyperthyroidism. 2. Diabetes. 3. Alcoholism. 4. Endocrinopathies.

Benign Atrophy

1. Fatty replacement. 2. Menopausal. 3. Malnutrition. 4. Gouty parotitis.

Immunologic Disease

Sjögren's Syndrome.

Neoplastic Disease Classification

Benign

1. Benign mixed tumor (pleomorphic adenoma). 2. Papillary cyst adenoma (Warthin's tumor). 3. Oncocytoma. 4. Monomorphic adenoma.

Malignant Tumors

1. Malignant mixed tumor. 2. Mucoid epidermoid tumor (low- or high-grade). 3. Adenoid cystic carcinoma. 4. Acinous cell carcinoma. 5. Adenocarcinoma. 6. Oncocytic carcinoma. 7. Clear cell carcinoma. 8. Squamous cell carcinoma.

Cysts and Congenital Lesions of the Parotid Gland

The parotid glands are affected more frequently by congenital lesions than any other of the salivary glands. Ranules affect the sublingual gland area, and lesser salivary glands are sites for the development of retention cysts.

12 Cysts of the Gland

Cysts of the parotid gland account for 2-5% of all parotid gland lesions. A cystic lesion can occur in the parotid gland presenting difficulties in diagnosis. Patients may be affected at any period of life.

Acquired Cysts

The etiology includes: Obstruction of the duct or ducts (postinflammatory), neoplasms, calculi associated with benign lymphoepithelial disease, and trauma. Intermittent obstruction from stricture, calculi, or mucous plugs may lead to dilatation and cyst formation. If there is no superimposed inflammation, a retention cyst may develop. The cells lining the cysts may be cuboidal, columnar, or squamous. They develop during years of intermittent obstruction. Once obstruction is complete the secreting membrane continues to function, thus accounting for the increase in size. Treatment of the patient with obstructive cysts usually is correction by surgical excision of the whole gland, with preservation of the facial nerve.

Congenital Cysts

Congenital cystic lesions of the salivary glands also occur mainly in the parotid glands. For the most part these lesions are ectodermal in origin. The congenital lesion of the parotid glands may be divided into dermoid cysts, branchial cleft cysts (type 1 and type 2), branchial pouch cysts, and congenital ductal cysts. Clinically these cysts can present as benign lesions within the parotid gland. For convenience, congenital first cleft lesions are classified as types 1 and 2. Both have different clinical behavior. Type 1 first cleft lesions appear as sinus tracts or swelling in the region of the posterior crease of the pina, concha, or anterior to the tragus. They are a duplication anomaly of the membranous external auditory canal. They can be positioned above, inferior, or medial to the facial nerve. The type 2 defect is also a duplication anomaly forming an anomalous external auditory canal and rudimentary pinna. Treatment of these lesions is surgical with preservation of the facial nerve.

Traumatic Lesions of the Salivary Glands

Injury to Ducts

Lacerations to the face posterior to the edge of the masseter muscle may result in damage to the parotid duct. Neglect of parotid duct injury in all probability will result in swelling of the face and salivary accumulation in a recently sutured wound. Diagnosis is made by the appearance of saliva in the wound during manual expression of the gland. Cannulation of the duct through the mouth will confirm the diagnosis. Every wound suspected of duct injury should be checked for facial nerve damage. When the duct is severed, repair over a catheter using fine, interrupted sutures. The catheter which leads into the mouth is sutured to the oral mucosa and removed in approximately 14 days. Suturing the duct is more easily accomplished using the operating microscope.

13 Injuries to the Facial Nerve

Laceration of the parotid duct should inevitably result in a check for facial nerve function. The main tract of the facial nerve can be damaged at the stylomastoid foramen, within the gland itself, or at the anterior edge of the parotid gland. When injury to the nerve is suspected, each division of the nerve is checked clinically. Early repair of the nerve is desirable. If delayed repair is considered necessary because of concomitant wound infection, marking of distal branches with metal clips at the time of original wound treatment is imperative.

Injuries to the Parenchyma

Damage to the parenchyma of a major salivfary gland should be treated with careful debridement and layered closure of the gland. Complications include chronic extraoral fistula or salivary gland cyst.

Acute and Chronic Inflammatory Diseases of the Salivary Glands

Acute Disease

Acute suppurative sialadenitis is largely confined to the parotid and submaxillary glands. Clinically, it presents with sudden painful swelling of the gland and periglandular soft tissues, with a fever and leukocytosis. Examination reveals a firm indurated tender salivary gland, with pus expressible from the ductal orifice. The most common causative organism is the coagulase-positive staphylococcus. Approximately one-third of all cases of acute suppurative disease of the parotid gland are associated with the postoperative state. Surgical parotitis has been estimated to occur in 1:1000 postoperative patients, with bilateral presentation in 20%. Other predisposing factors include debilitation, dehydration, and poor fluid and electrolyte management. The disease may occur in children. A culture from the duct should be undertaken. A blood culture also may be obtained. Treatment is with an appropriate antibiotic and rehydration.

Chronic Recurrent Bacterial Sialadenitis

This is more characteristically seen in the parotid gland. It occasionally may be bilateral. The most common cause is duct obstruction. Other causes include debilitation or intense fluid restriction for cardiac or renal disease. Clinically if presents with a history of recurrent mildly painful gland enlargement which the patient often associated with eating. A decreased rate of salivary secretion and an alteration in the character of secretions occur. There appears to be an interrelationship between acute and chronic inflammatory disease. Sialectasis, duct ectasia, and low-grade progressive acinar destruction result. These result in further reduction in salivary flow and stasis. The advanced cases of chronic sialadenitis and fibrosis are accompanied by lymphocytic infiltration. Sialography may demonstrate duct ectasia or dilatation, with atrophy of the acinar elements. Treatment should be conservative. Sialogogues such as lemon or chewing gum may stimulate salivary flow and ductal irrigation. Periodic massage of a gland may assist. Treatment alternatives other than conservative management include tympanic neurectomy or superficial parotidectomy.

14 The end result of chronic sialadenitis may include sialectasia, Kussmaul's disease, and local duct obstruction by stricture. In chronic sialectasia the patient complains of diffuse swelling of one parotid gland which may slowly increase over several months or years. Histologically, saculation of the ductal and acinar elements is found with lymphocytic infiltration.

Kussmaul's Disease

As a result of mucous plugs in one or more of the collecting salivary ducts, this disease typically occurs in dehydrated patients. Recurrent swellings are common and extremely painful on eating. The most serious complication is recurrent acute suppurative sialadenitis. The treatment consists of gentle pressure and sialogogues.

Local Duct Obstruction by Stricture

The etiology of ductal stricture involving Stenson's duct includes ill-fitting dentures and poor oral hygiene. Internal stricture formation is due to calculus, infection, trauma, neoplasm, or congenital failure of development. In any event, the patients complain of periodic painful swelling. Signs and symptoms of acute infection may occur, reaching the stage of abscess formation and sepsis. Probing of the duct and sialography will outline the stricture. Treatment consists of ductal ligation, fistulization of the duct into the mouth, or gland excision. Sialolithiasis is both a cause and consequence of recurrent sialoadenitis. Stones are composed of inorganic calcium and sodium phosphate salts, and are thought to arise around a small mucous plug or debris. The sequence of events includes initial stasis of secretions with ductal metaplasia and static cellular ductal debris. Ascending bacterial infection promotes further ductal metaplasia and the formation of calcareous debris. The cycle results in progressive stone enlargement contributing to duct obstruction and low-grade recurrent sialadenitis. Complete obstruction leads to marked tissue edema and secondary acute infection. The patient complains of painful swelling when eating. A repeated history of spontaneous extrusion of small calculi from the ducts may occur. Complications include acute abscess formation, sinus tract, and salivary fistulas. Treatment consists of intraoral removal of stones. Repeated stone formation may require excision of the affected gland.

Specific Granulomatous Disease

Mycobacterium Tuberculosis

The primary tuberculosis in salivary tissue occurs most commonly in the parotid gland. Although primary infection of the parotid tissue is seen, it would seem more likely to occur from infection of the tonsils or elsewhere in the oral cavity. Treatment consists of specific antitubercula chemotherapy.

Cat-Scratch Disease

The causal agent in cat-scratch disease is thought to be a virus found in many household pets. The disease results in necrotizing granulomatous infection.

15 Sarcoidosis (Heerfordt's Disease)

Sarcoidosis of the uveal tract, and lacrimal and salivary glands is fairly uncommon. Parotid gland and parotid lymph node involvement is estimated to occur in approximately 6% of all cases. Diagnosis is made by biopsy. Facial nerve paralysis may occur.

Fungal Disease

Actinomycosis of the parotid gland has been reported rarely in suppurative parotitis. This infection usually follows dental extraction. Progressive symptoms are fever, weight loss, and trismus. High doses of intravenous penicillin are administered over a prolonged period of treatment.

Inflammatory Disorders of Viral Etiology

Mumps (Epidemic Parotitis)

Mumps is the most common of all salivary gland diseases. It causes an acute febrile illness with a prodrome of approximately 2-3 weeks. It primarily infects young adults and children, classically 4-7 years of age. The onset of such a disease is typified with fever, headaches, and painful swelling of the parotid glands. Serum antibodies to mumps S and V antigens with a titer of greater than 1:920 indicates recent infection. Complications of the disease include parotid gland sialectasia, recurrent chronic suppurations, unilateral hearing loss, diabetes secondary to pancreatic fibrosis, sterility secondary to gonadal involvement, and meningoencephalitis.

Salivary Gland Inclusion Disease

This is a disease occurring in neonates and is a form of cytomegalic inclusion disease. Infection occurs transplacentally, without evidence of maternal disease. Hepatosplenomegaly, jaundice, thrombocytopenic purpura, and involvement of the nervous system can occur. Other variants may produce local parotitis. The diagnosis rests on viral isolation.

Secondary Inflammatory Disorders of the Salivary Glands

Radiation

Radiotherapy for lesions of the head and neck causes acute tender swelling of the major salivary glands. A resultant destruction and atrophy of the minor salivary glands occurs. Dryness of the mouth will develop. Drug effects on salivary glands are of two distinct types:

Idiosyncratic and Direct Effects: Direct effects include clinical sialadenitis following injection of certain heavy metals, including mercury and bismuth. Iodine causes diffuse and tender swelling of the salivary glands within 2-3 days of injection. Salivary gland enlargement also has been noted as an idiosyncratic effect. Atropine derivatives cause enlargement of the glands because of the side effect of making saliva more viscid and thick. Phenylbutazone has been noted to produce xerostoma in 20% of the patients. Phenothiazine derivatives all exert

16 an atropine-like effect. Other drugs noted to cause gland enlargement include methimazole, thiocyanates, and thiourea.

Immunological Diseases of Salivary Glands

Sjögren's Syndrome

Sjögren's syndrome is characterized by a triad of symptoms: xerostoma, keratoconjunctivitis sicca, and a connective tissue disorder. The latter is more commonly rheumatoid arthritis in over 50% of the cases, but systemic lupus, polyarteritis nodosa, dermatomyositis, or scleroderma may accompany the other features. Sjögren's syndrome should be distinguished from Mikulicz's disease, an enlargement of the lacrimal and parotid glands of unknown origin. Women are affected by Sjögren's syndrome more frequently than men. The first signs are seen in early middle-age.

Manifestations in the oral cavity are always present, but may only be elicited on careful examination. Dry lips or mouth and diminished salivary flow are the two most common symptoms, often accompanied by difficulty in masticating food and by dental problems. A routine oral examination reveals dryness and cracking of the oral mucosa. The parotid glands generally are enlarged bilaterally and the patient may have noticed a chronic progressive enlargement. Major histopathologic features are atrophy and loss of acinar tissue, with distortion of lobular architecture. Lymphoid infiltration occurs.

The serum proteins in Sjögren's syndrome include a rise in the gamma globulin fraction. Hypergammaglobulinemia usually is broad-based with the IgG fraction being particularly elevated. The rheumatoid factor in Sjögren's syndrome is significantly increased. Antinuclear antibodies are common in Sjögren's syndrome, with most investigators reporting their presence in more than 50% of the patients.

Tumors of the Parotid Gland

Management of Benign Parotid Tumors

Benign Mixed Tumor (Pleomorphic Adenoma)

Benign mixed tumors of the parotid gland account for up to 75% of all parotid tumors. Treatment is surgical excision of the parotid gland with preservation of the facial nerve.

Warthin's Tumor (Adenocystoma Lymphomatosum)

Warthin's tumor accounts for approximately 20% of the benign tumors involving the salivary glands, occurring most commonly in males in the fifth decade. It is notable for its tendency toward multiplicity, bilateral tumors of this type being common. This occasionally makes evaluation of tumor recurrence somewhat difficult. It is interesting to note that of 120 patients studied in Barnes Hospital, eight lesions (approximately 6%) were discovered as occult tumors in the radical neck dissections that were done to control reasonable extension of another tumor. As Warthin's tumors have a low incidence of recurrence, parotidectomy with facial nerve preservation is the treatment of choice.

17 Management of Malignant Parotid Tumors

It should be remembered that while a consensus of opinion exists concerning the management of facial nerve in the treatment of benign tumors of the parotid gland, this is not the case with malignant tumors. A disparity of opinion exists in the relationship with reference to definitive treatment.

Diagnosis

When considering treatment for the management of malignant tumors of the parotid gland, histologic diagnosis is important. Hamberger has stated that the prerequisite for adequate treatment of parotid tumors is the correct diagnosis based on a well delineated histologic type of tumor. It seems that the histologic type, the biologic behavior, and the sizew of the tumor all may influence the proposed treatment regimen. In view of this, each of the major histologic types will be discussed in relation to facial nerve preservation, and whether or not radical neck dissection would be of benefit to the patient.

Mucoepidermoid Carcinoma

The most common type of malignant tumor found in the parotid gland is the mucoepidermoid carcinoma. This tumor accounts for 50% of all malignant tumors reported in a major series. It is a tumor of varying malignant potential, usually separate into three major grades: low grade, intermediate grade, and high grade. By far the most common is the low-grade malignancy, occurring in approximately 70-95% of the series presented. In low- grade mucoepidermoid carcinoma (female/male ratio is 2:1) it would appear that unless the facial nerve is affected, parotidectomy with facial nerve preservation, without radical neck dissection, is the treatment of choice.

In high-grade mucoepidermoid carcinoma a wide en bloc excision with a radical neck dissection should be done. The facial nerve would be sacrificed if it in any way compromised a surgical margin. It is felt that because of the high recurrence rate and low 5-year survival rate (41%), a total radical parotidectomy with sacrifice of the facial nerve should be performed, with an accompanying radical neck dissection. Intermediate-grade tumors present difficulty in management, but probably can be managed similar to low-grade lesions, reserving radical neck dissection for those patients showing clinical evidence of cervical lymph node involvement.

Acinar Cell Carcinoma

Acinar cell carcinoma has been described as an uncommon low-grade, slow-growing malignant tumor. It is said to constitute approximately 10% of all malignancies of the parotid gland. There is a low incidence of tumor spread to regional lymph nodes (8%). In view of this, treatment for acinar cell carcinoma of the parotid gland should be total excision of the gland with preservation of the facial nerv unless to do so would compromise the surgical margins. In view of the limited number of node metastases reported, elective radical neck dissection is probably not indicated.

18 Adenocystic Carcinoma (Cylindromas)

These tumors are relatively rare in the parotid gland, constituting 2% of the parotid neplasma reported. Although slow growing, adenocystic carcinoma is characterized by its propensity for nerve invasion and late recurrence. Because of this tendency for late metastasis it is difficult to analyze the effectiveness of various treatment regimens. Surgical survival based on 5-year observations are inadequate for proper evaluation. A reasonable treatment for patients with adenocystic carcinoma should consist of a total parotidectomy including a wide cuff of parotid tissue, with dissection of the upper jugular and subparotid lymph nodes. The facial nerve probably should be sacrificed because of the propensity of this tumor for perineural invasion. Frozen section biopsies of the severed nerve should be obtained until clear margins are reported. There seems to be no advantage to performing elective radical neck dissection because of the low instance of metastatic involvement of the cervical nodes. Postoperative irradiation also should be considered. The 5-year survival is 30%.

Malignant Mixed Tumor

The treatment of a mixed malignant tumor is difficult based on current reports and literature. Although far from conclusive, the evidence points to treatment of these tumors with a total parotidectomy, plus dissection of the subparotid nodes and upper jugular nodes, with sacrifice of the facial nerve whenever necessary to preserve the surgical margins. With the rate of documented cervical metastases ranging from 20-25%, the overall benefit to the patient of a radical neck dissection is open to question, especially in view of the high incidence of recurrence following radical neck dissection. Most authors agree that radical neck dissection is indicated when positive lymph nodes are apparent. The benefit of elective dissection is in doubt.

Adenocarcinoma

Adenocarcinoma appears histologically to be of two types: Type 1 exhibiting low- grade characteristics and responding to a treatment regimen of subtotal parotidectomy and partical resection of the facial nerve as necessary. Type 2 is a high-grade tumor, where treatment with radical parotidectomy and neck dissection appears imperative. In the treatment of low-grade adenocarcinoma with subtotal parotidectomy and partial resection of the facial nerve where necessary, radical neck dissection appears probably of no benefit. Such treatment leads to a survival rate of approximately 95%. In the treatment of high-grade adenocarcinoma, total parotidectomy and facial nerve sacrifice appears to be the treatment of choice. Even so, a survival rate of 40% appers to be the normal range.

Squamous Cell Carcinoma

Squamous cell carcinoma of the parotid gland occurs in approximately 3-20% of all malignancies of the parotid gland. With a determined 5-year survival rate in the range of 20%, total parotidectomy with excision of a wide margin of normal tissue and a radical neck dissection with facial nerve sacrifice appears to be the treatment of choice.

Since metastases to the cervical lymph nodes range from 50-75% it seems reasonable that a radical neck dissection should be part of the primary treatment plan.

19 Undifferentiated Carcinoma

Undifferentiated carcinoma constitutes a small portion of malignant tumors of the parotid gland. It appears that no matter what treatment regimen is selected, prognosis for the patient with undifferentiated carcinoma is poor. The accepted treatment consists of radical parotidectomy with facial nerve sacrifice and a radical neck dissection.

Management of Severed Facial Nerve

After the decision has been made to sacrifice the facial nerve, the surgeon immediately faces the question of how to deal with the consequences of his treatment. It would seem reasonable that if no contraindications exist, repair of the severed facial nerve should be accomplished wherever possible. Surgical repair is rarely possible or indicated when the main trunk and its branch were excised. Such resection usually extend from the stylomastoid foramen, sacrificing most of the peripheral branches and leaving little to graft. Therefore, surgical repair and nerve grafting are considered unrealistic in patients requiring radical ablative surgery, radiation, and with a poor prognostic post-treatment.

On the other hand, patients with low-grade mucoepidermoid mixed tumors or adenocystic carcinoma can and may be treated with immediated nerve grafts.

In general, the direct immediate autograft of a free nerve graft, when feasible, gives results superior to those of cross-over anastomosis.

Tumors of the Minor Salivary Glands and Submaxillary Glands

Treatment of tumors of these two areas in no way differs from that of treatment of the parotid gland. In the submaxillary gland, benign tumors account for 50% of the tumors found.

Of carcinomas in the submaxillary gland, adenocystic carcinoma is the most common. In minor salivary glands and the sublingual glands the incidence of malignancy is 80% while in parotid glands it is 20%.

Oncocytoma (Oxyphil Adenoma)

This benign tumor is a well-encapsulated circumscribed lesion with cystic areas. The predominant cell type is the eosinophilic oncocyte. The peak age for this tumor is the sixth or seventh decade. The treatment of choice is a superficial parotidectomy to include good margins of the tumor mass.

Recurrence is possible with incomplete excision.

Survival for Malignant Tumors of the Salivary Gland

Survival for malignant tumors of the salivary gland appears not to follow the rules that are normally set for cancers of the head and neck. Survival in terms of 5 years may not be appropriate for many of these lesions in view of their propensity for slow growth and ultimate

20 reappearance up to 20 years after the initial diagnosis. Successful treatment is dependent upon an accurate pathologic diagnosis with appropriate management.

Factors Affecting Cure Rate

Facial Nerve Paralysis

Facial nerve paralysis in association with a parotid gland mass is generally believed to carry an adverse prognosis. The survival rate after the onset of facial nerve paralysis appears to be 2.7 years. The instance of metastases in patients with facial nerve paralysis is high.

Pain

Pain does not appear to be a useful criteria for malignancy. There appears to be an equal instance of pain in both benign and malignant tumors.

Other Facts

It would appear that the younger the patient the better the prognosis probably related to the high instance of low-grade tumors in the younger age group. Fixation to a deep structure with extension beyond the confines of the parotid and with neck metastases obviously reduce the survival figures.

Tumors of the deep portion of the gland appear to have a survival rate similar to those in the body or tail.

Survival rate obviously depends on the pathologic diagnosis with low-grade mucoepidermoid and acinous cell carcinoma, allowing excellent survivals. Malignant mixed, undifferentiated carcinoma, squamous cell carcinoma, and adenocarcinoma would appear to have a much poorer survival rate.

At this time, the clinical staging (TNM) system of classification of salivary gland neoplasms is not widely used or accepted. The American Joint Committee for Cancer Staging end results were reported in 1976 and a clinical classification system proposed for major salivary gland tumors. This system has not been tried.

T1: Solitary nodule, freely mobile, 0-3 cm. Facial nerve intact. T2: 3-6 cm, solitary, freely mobile or reduced mobility of nodule or with skin fixation. Facial nerve intact. T3: Greater than 6 cm, multiple nodules, ulceration, or deep fixation. Facial nerve dysfunction.

21 Bibliography

1. Cancer of the Head and Neck. Edited by John Conley, Kingsport Press, Inc, Kingsport, Tennessee, 1967.

2. Cotroversy in Otolaryngology. Edited by J. B. Snow, Jr, W. B. Saunders Co, Philadelphia, 1980.

3. Symposium on Salivary Gland Diseases. Edited by W. P. Work and M. E. Johns, Otolaryngol. Clin. N. Am., June 1977.

22 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 18: Carcinoma of the Oral Cavity and Pharynx

Carcinoma of the Head and Neck

Because of the paucity of well-designed and controlled prospective studies comparing treatment modalities, it is difficult to unequivocally state the ideal therapy for a specific stage of cancer originating in the head and neck. In this chapter I will attempt to present the currently available data which describes the incidence, staging, and the general principles of management of cancer of the oral cavity and pharynx. In addition, data specific to different sites within the oral cavity and pharynx will be discussed. Patients with carcinoma of the head and neck require careful workup and a multidisciplinary approach to their treatment determination and management. This includes the evaluation of radiation oncology, medical oncology, dentistry, social services, and other supporting services as deemed necessary by the head and neck surgeons. Appropriate diagnostic evaluation including CT scan, angiography, and other diagnostic tests are utilized when indicated.

Oral cavity and pharyngeal carcinomas are said to make up approximately 3.25% of all human cancers. They are responsible for 5% of all cancers in males and 2% of all cancers in females. In 1980 3% of all cancer deaths in males were from carcinoma of the oral cavity and pharynx and 1% of all cancer deaths in females were from oral cavity cancer. In 1980 there were 25500 new oral cavity and pharyngeal carcinomas and 8800 deaths from carcinoma of the oral cavity and pharynx. It is interesting to note that carcinoma of this region accounts for eight out of 100.000 cancers in the black population in the USA, but only 4.4 per 100.000 in the white population. This represents an 82% higher incidence in blacks. In the USA five out of every 100 cancer deaths in males will be from cancer of this region. In the East and Far East oral and pharyngeal carcinoma account for almost half of all malignant neoplasms. Ninety percent of all carcinomas arising in the oral cavity and pharynx are squamous cell carcinomas. The balance is made up of minor salivary gland tumors and occasional melanomas and sarcomas.

Tumors of this area have been related to tobacco consumption, heavy drinking of alcohol, and particularly with chewing tobacco and the use of betel nut. Sunlight exposure has been particularly related to carcinoma of the lower lip. Poor oral hygiene, mechanical irritation from sharp teeth and the Plummer-Vinson syndrome have been implicated as possible casues of oral cancer.

The presence of leukoplakia of the oral cavity and pharyngeal mucosa has been considered by some as a premalignant lesion. Properly used, however, the term leukoplakia must be considered a clinical diagnosis of a white patch only, and not necessarily a premalignant lesion. Histologic changes such as hyperkeratosis alone can cause this clinical finding. However, an area of leukoplakia may harbor dysplasia, carcinoma in situ, or invasive carcinoma. In one review of 3256 biopsies taken from leukoplakia of the oral cavity, carcinoma in situ or severe dysplasia was observed in 4.5% and invasive carcinoma in 3% (Waldran, C. A., Shafer, W. G.: Cancer 36:1386, 1975). Leukoplakia thus must be considered an area of potential malignancy and should be carefully evaluated and a biopsy taken when indicated.

1 Anatomic Boundaries and Subdivision of the Oral Cavity and Pharynx

Oral Cavity

The oral cavity extends from the skin vermillion border of the lips to an imaginary horizontal line which can be dropped superiorly from the junction of the hard and soft palate to the circumvallate papillae of the tongue inferiorly. There are eight anatomic subdivisions of the oral cavity. These are:

Lips Retromolar trigone Buccal mucosa Floor of the mouth Lower alveolus Hard palate Upper alveolus Anterior two-thirds of the tongue.

The lymphatic drainage of the oral cavity primarily is to the jugulodigastric, upper deep cervical, submental, and submandibular nodes. Each anatomic subdivision has a specific drainage pattern.

Pharynx

The pharynx is subdivided into three parts. The nasopharynx, oropharynx, and hypopharynx.

Nasopharynx

The anterior border of the nasopharynx is the nasal choanae, the roof is the sloping skull base which becomes continuous with the posterior pharyngeal wall. The inferior posterior limit is an imaginary line drawn horizontally in the plain of the hard palate. The lateral wall is composed of the torus tubarius, eustachian tube orifice, and fossa of Rosenmüller.

Oropharynx

This region begins anteriorly where the oral cavity stops and extends from the plain of the hard palate superiorly to the plain of the hyoid bone inferiorly. The lateral wall is comprised primarily of the tonsil and tonsillar fossa, its pillars, and the lateral pharyngeal wall. Posteriorly it is bounded by the pharyngeal wall mucosa which extends from the superior to inferior limits described above. Subdivisions of the oropharynx include: (1) tongue base including pharyngoepiglottic folds and vallecula, (2) faucial arch including the soft palate and anterior tonsillar pillar, (3) tonsil and tonsillar fossa, (4) pharyngeal wall which includes the posterior tonsil pillar, the lateral and posterior pharyngeal walls.

Hypopharynx

This portion of the pharynx extends from the plain of the hyoid bone above to the plain of the lower border of the cricoid cartilage below. It does not include the larynx and has three parts: (1) the pyriform sinus, (2) the postcricoid area, and (3) the posterior pharyngeal wall.

2 TNM Staging (AJC 1980)

Oral Cavity

Tx: Tumor not accessible by the rule. T0: No evidence of primary tumor. Tis: Carcinoma in situ. T1: Tumor 2 cm or less. T2: Tumor more than 2 cm but less than 4 cm. T3: Tumor greater than 4 cm. T4: Tumor greater than 4 cm which also involves deep invasion of the antrum, pterygoid muscles, tongue base, or skin of the neck.

Nasopharynx

Tis: Carcinoma in situ. T1: Tumor confined to one site. T2: Tumor involving two site. T3: Tumor extension into nasal cavity or oropharynx. T4: Tumor invasion of skull and/or cranial nerve involvement.

Oropharynx

Tx: Tumor not accessible by the rule. T0: No evidence of primary tumor. Tis: Carcinoma in situ. T1: Tumor 2 cm or less. T2: Tumor more than 2 cm but less than 4 cm. T3: Tumor greater than 4 cm. T4: Tumor greater than 4 cm which also involves deep invasion of the antrum, pterygoid muscles, tongue base, or skin of the neck.

Hypopharynx

Tis: Carcinoma in situ. T1: Tumor confined to site of origin. T2: Tumor extension to adjacent region or site without fixation of the larynx. T3: Same as T2 but with fixation of larynx. T4: Massive tumor invading bone or soft tissue of neck.

Staging (see Fig. 18.1)

Stage I: T1N0 Stage II: T2N0 Stage III: Includes T3N0 or T1T2T3 and N1. Stage IV: Includes all other TN classes not included above.

Neck Node Staging (see Fig. 18-2).

3 General Principles

It is important to remember that head and neck cancer is a multisystem disease. These patients have a previous history of heavy alcohol intake with resultant liver disease, chronic obstructive pulmonary disease from abuse of tobacco, nutritional depletion as a result of the tumor and other personal hygiene deficits, and have a generalized immune suppression as a result of the neoplasm, alcoholism, nutritional suppression, or all three. Careful endoscopy under general anesthesia with mapping and careful recording of the lesion using the written word and with a drawing is indicated. Esophagoscopy is carried out along with laryngoscopy during evaluation of the oral cavity and pharynx. This is done as there is a 9-10% incidence of synchronous primary tumors occurring at the same time as the presenting cancer. Bronchoscopy generally is not as productive as a chest x-ray in defining a second primary and, as such, is not mandatory. In the oral cavity the lesions are tattoed using india ink. This will facilitate later surgical attack, particularly when cytoreduction occurs as a result of adjuvant chemotherapy or radiation therapy. Neither the liver-spleen scan nor bone scan has been found to be of diagnostic value in most patients with head and neck cancer. Consultations are obtained with medical oncology, radiation therapy, and other consulting services as indicated. It should be noted that chemotherapy, at the present time, is still unproved as a therapeutic modality in the primary treatment for head and neck cancer and, as such, its use should be restricted to new head and neck cancer patients in the protocol setting. A general rule as to prognosis is that as one proceeds anatomically from the lips posteriorly to the hypopharynx the prognosis gets poorer.

As far as general principles of treatment are concerned it can be said for the oral cavity that for T1 and T2 lesions either radiation therapy or surgery will handle the tumor with equal effectiveness. For advanced lesions either surgery alone or combination therapy using either pre- or postoperative radiation is acceptable. These are general treatment principles, however, and there are many arguments which have been put forth favoring surgery, radiation therapy, or combinations thereof. Each patient must be individually evaluated and the therapy based on the skills of the radiation therapist, the surgeon, and what the patient can tolerate.

Management of neck metastasis when clinically present, in most cases requires surgery. There are many advocates, however, who have pointed out that neck nodes less than 2 cm can be controlled 80-85% of the time by radiation therapy alkone (Wisenberg et al: Cancer 29:1455, 1972; Million: Cancer 34:149, 1974, and Weller et al: Am J Roentgenol 126:236, 1976). These therapists also point out that the N0 neck can be controlled in 85-90% of cases by radiation therapy alone. Most surgeons and many radiation therapists, however, recommend neck dissection either alone or in combination with radiation therapy for clinically positive nodes. The clinically negative neck is another story. There has been considerable discussion and debate over whether or not elective neck dissection is of value. In general, it has been stated that if the incidence of occult metastases in the neck is higher than 25-30%, an elective neck dissection is indicated. Other advocates would say, however, that if radiation therapy is being used to treat the primary cancer, occult metastasis in the neck also can be controlled with radiation therapy. There are many reports which state the incidence of occult metastasis to the neck. These generally have been used on cases in which a clinically negative neck was treated surgically and subsequent pathologic evaluation demonstrated positive microscopic or clinically nonpalpable nodes to be present in a neck dissection specimen.

4 These percentages vary depending on whose series you read, but generally they are all reasonably close in incidence. For the oral cavity, Jesse et al reported the following (Am J Surg 120:505, 1970):

Site Occult Nodes (%)

Oral tongue (N=121) 34 Floor of the mouth (N=123) 30 Buccal mucosa (N=95) 9 Lower gum (N=48) 19

Ogura reported the following incidence of occult metastasis for these pharyngeal sites (Ann Otol Rhinol Laryngol 80:646, 1971):

Site Occult Nodes (%)

Pyriform sinus (N=98) 38 Base of tongue (N=34) 22 Posterior pharyngeal wall (N=6) 0

In a study reported by this author in the Archives of Otolaryngology, December 1981, a 10% incidence of occult metastasis was noted for carcinoma of the tonsil. It should be noted that the occult metastasis is not to be confused with those patients presenting with clinically palpable lymph nodes. Spiro and Strong (Clin Bull 6:3, 1976) in a review of admission lymph node status for oral cavity carcinoma at Memorial Hospital, noted the following:

With Palpable Nodes at Admission

Site (%)

Floor of the mouth (N=804) 39 Tonsil (N=650) 61 Tongue Base (N=136) 76 Oral (N=314) 31 Palate Hard (N=123) 15 Soft (N=299) 37 Buccal mucosa (N=248) 36 Alveolus (N=179) 35.

However, it should be noted that for tumors arising in the hypopharynx, metastasis to the neck at the time of presentation occurs in about 70% of the patients. Contralateral disease has been noted by a number of authors to occur in 10% of cases at presentation. For the nasopharynx, localized presentations with disease confined to the site of origin is relatively unusual occurring in only about 25% of the cases. Regional metastases are frequently the presenting sign of nasopharyngeal carcinoma, and regional disease occurs in at least 50% of patients who present with nasopharyngeal carcinoma. In this group of patients, however,

5 distant metastases occur frequently and should be searched for. Lederman, in 1961, in his textbook Cancer of the Nasopharynx, reviewed 150 cases of nasopharyngeal carcinoma and found the frequency of metastasis to be as follows:

Jugulodigastric nodes 70% Upper deep cervical nodes 66% Jugulo-omohyoid nodes 34% Spinal accessory nodes 28% Inferior cervical nodes 20%.

It should be noted that the jugulodigastic node is the most common site of lymphatic metastasis from the nasopharynx to the neck. At the same time, the most common site of squamous cell carcinoma that metastasizes to the posterior triangle is the nasopharynx.

With this information we can now evaluate the value of elective neck dissection. Arguments against it include the following:

1. Radical neck dissection results in a significant morbidity. 2. Many unnecessary operation are performed. 3. Cure rates are no worse if one waits for occult disease to become palpable. 4. Radiation therapy effectively controls occul metastasis.

Arguments for elective neck dissection would include:

1. A high incidence of occult disease in the N0 neck. 2. Waiting may result in increased distant metastases. 3. Many patients are not responsible in their follow-up and are placed in greater jeopardy of later metastases by not being treated promptly. 4. If the primarily tumor is being treated surgically and the neck must be entered to treat it, then an elective neck dissection should be done at the same time.

It is clear then, if an elective neck dissection shows positive nodes the survival is better than in the patient who presents with a clinically positive neck. Spiro (Arch Surg 107:382, 1973) noted a 26% 5-year cure rate in those patients who had elective neck dissection with positive nodes, and 18.9% 5-year determinant cure in those who presented with a clinically positive neck requiring a therapeutic neck dissection. This retrospective analysis was statistically evaluated and felt to be of borderline significance. It is well known, however, that the presence of cervical node metastasis significantly reduces survival. This study and other studies are flawed by the fact by the fact that they are retrospective studies rather than prospective studies. Another retrospective study, somewhat better designed since retrospective site and age-matched controls were used is that reported by Stell (Proc R Soc Med 68:83, 1975). In this group of patients with T1 to T4 oropharynx, hypopharynx, and laryngeal carcinomas, Stell evaluated those patients who had an elective neck dissection (32 patients) and compared them to 32 matched patients who did not have an elective neck dissection and who did not receive neck treatment until they developed positive cervical nodes. I will refer to this as the "wait-and-see" approach. At 3 years he noted that the elective neck dissection group (32 patients) had an absolute survival of 35% whereas in the wait-and- see group the survival was 57%. He looked at neck recurrence, primary recurrence, distant

6 metastasis, and intercurrent disease and found no difference in the two groups. This was statistically analyzed and found to be significant at a value less than 0.02. Another study which we cannot ingore is that by Vandenbrouck and colleagues (Cancer 6:386, 1980). This was a prospective randomized study of patients with T1, T2, and T3N0 oral cavity lesions. They were randomized into two treatment groups: those receiving elective neck dissection and those with a wait-and-see approach, receiving neck dissection only after neck metastasis presented. They found a life table survival rate of 78% in the elective neck dissection group and 75% in the wait-and-see group. They also found that the incidence of neck recurrence, primary recurrence, distant metastasis, and intercurrent disease were similar for both groups. This prospective study was statistically analyzed and it was found that there was no difference between the two groups. This is a most important study of the type of which we need more in evaluating the treatment of head and neck cancer patients. It would seem to indicate that a wait-and-see attitude in the patients presenting T1, T2 and T3N0 oral cavity cancer is just as effective as elective neck dissection. Based on this information, then, it is this author's recommendation that elective neck dissection be done when all of the following criteria are present: (1) a greater than 25% occult disease is likely; (2) no radiation therapy is to be used to treat the primary disease, and (3) poor patient follow-up is expected. Furthermore, modified neck dissection should be considered for these patients.

Specific Sites of Oral Cavity and Pharynx

Carcinoma of the Lip

Carcinoma of the lip accounts for 25-30% of all cancers of the oral cavity. Lip cancer constitutes approximately 0.6% of all human cancers. The lower lip is the site most frequently involved (95%); the upper lip and commissure being responsible for the other 5% of lip cancer. This disease is most common in patients 50-70 years old, and there is distinct male preponderance (95%). Lip cancer has been associated with a fair complexion, with exposure to sunlight, with pipe smoking, and with the predisposing condition of actinic cheilitis - a skin disorder due to exposure to sun, wind, and rain. Eighty-five percent of lip cancers arise halfway between the midline and the commissure of the lower lip. Although the upper lip is an infrequent site for cancer, the 5-year survival for carcinoma originating at this site is significantly reduced compared to the lower lip. Because these cancers are so obvious, usually they are diagnosed early and neck metastasis is relatively infrequent, occurring in only 5-10% of patients at the time of diagnosis. Almost all lip cancers are squamous cell and these account for 98-99% of all carcinomas involving the lip. Other neoplasms that occur in this area include basal cell carcinoma, keratoacanthoma, and minor salivary gland tumors. Although neck node metastases are relatively uncommon, as the size of the lesion increases, the frequency of neck metastases also increases.

In most cases the treatment of carcinoma of the lip has been surgical excision. Radiotherapy, however, also has been successful in the management of lip carcinoma. The overall survival is excellent and 80-90% 5-year cure rates have been reported for carcinoma of the lower lip. Carcinoma of the upper lip, however, has been associated with a 50% regional metastasis rate and 5-year survivals of 40-50%.

As far as surgery is concerned there are numerous operations described for lip cancer. However, two operations, either wedge excision or a rotation flap, will successfully manage

7 90% of all lip cancers. Important principles to remember are that up to 30% of the lip can be excised without significant deformity and that the normal commissure should be preserved if at all possible. Marking the vermillion border with a microdot of india ink is valuable in closure. Elective neck dissection is not indicated in lip cancer.

Although not described here, the otolaryngologist/head and neck surgeon should be familiar with the lip shave and vermillion advancement, the Abbe-Estlander operation, the Bernard's reconstruction, the Burrow's operation, and how to correct the rounded commissure.

Carcinoma of the Buccal Mucosa

Buccal carcinomas occur in patients of more advanced age than do those of other oral cavity sites. The mean age for buccal carcinomas is in the seventh decade. Buccal carcinoma also occurs more frequently in men than women except in certain areas of the southeast where snuff dipping and tobacco chewing is as frequent in women as in men. In India where cancers of the oral cavity represent one of the most frequent sites of cancer in the body, buccal mucosal carcinomas are particularly frequent. In India and the Far East these have been associated with the chewing of betel nut.

The most common site of origin of buccal carcinomas is that part of the mucosa lying against the lower third molar. It also has been stated, in the past, that carcinomas arising in the posterior buccal mucosa do less well than those with anterior lesions. Krause was not able to substantiate this finding in his review of carcinoma of the oral cavity.

Although these cancers are in fairly obvious sites in the oral cavity, they frequently present as advanced tumors with trismus or neck metastis as the first clinical sign. Although several authors have stated that lymph node metastasis is relatively unusual, Krause et al (Arch Otolaryngol 97: 64, 1973) and Dhawan (Surg Gynecol Obstet 137:31, 1973) found that lymph node metastasis occurred in 37-58% of the cases.

An important distinction to be made histologically is that verrucous carcinomas do occur on the buccal mucosa. However, this should be distinguished from exophytic invasive squamous cell carcinoma. The latter is more common than the verrucous carcinoma. Kraus and Perez-Mesa (Cancer 19:26, 1966) described 77 oral cavity verrucous carcinomas, 50 of which originated on the buccal mucosa. It is interesting to note that 13 of their verrucous carcinomas were treated by radiation therapy and all 13 recurred. Squamous papillomas and pseudoepitheliomatous hyperplasia are in the differential diagnosis of buccal carcinoma.

Both surgery and radiation therapy have been advocated as the treatment of choice for buccal carcinomas. In the case of verrucous carcinoma, it appears that surgery is the preferred treatment modality. For invasive squamous carcinoma 5-year survivals have been reported to range from 40-70% depending on the stage of disease. Krause, in comparing surgery, radiation, and combination therapy, found the highest survival in his surgically treated group. However, it is important to note that this surgery group had a much lower incidence of regional metastasis than the radiation- or combination-therapy-treated groups. Once again, it is difficult to present data from the literature which specifically proves surgery or radiation therapy to be superior one to the other. The choice of therapy must be based on the size of

8 the lesion and the presence or absence of regional metastasis, and the level of surgical and radiation therapy skills that are available.

Carcinoma of the Floor of the Mouth

The floor of the mouth is the U-shaped area situated between the lower alveolus and the tongue. Excluding the lips, carcinoma of the floor of the mouth is the second most common site of squamous cell carcinoma in the oral cavity. It is said to account for 10-15% of all oral carcinomas and is the most common intraoral site of carcinoma in the black population. The disease is preponderant in males, and in Krause's series there was a 4:1 male/female ratio. The usual association with tobacco and alcohol use has been noted. Lymph node metastasis is fairly common with the submandibular triangle being the earliest area of involvement. Because of the more common anterior location of these carcinomas the frequency of bilateral lymphatic metastasis is not uncommon. In Krause's series four of 21 patients with T3 lesions had bilateral lymph node metastasis. For small lesions Spiro and Strong reported they were able to control 80% of those lesions 4 cm or less in diameter. For more advanced lesions, Krause and co-workers found combination therapy to give improved survival over surgery or radiation therapy alone. The general principles of therapy discussed earlier (surgery or radiation for early lesions and combination for advanced lesions) seems to hold for the floor of the mouth, as well as other sites in the oral cavity.

It is important to note the frequency of multifocal squamous carcinomas occurring in patients who present with carcinoma of the floor of the mouth, buccal mucosa, and soft palate and, as such, careful examination of the upper aerodigestive tract for a synchronous secondary primary lesion is required.

Carcinoma of the Alveolus

Carcinomas of the alveolus are more frequent in the lower jaw than the upper jaw and generally are noted to arise more commonly over the premolar regions. Alveolar carcinoma is more common in areas where tobacco chewing is frequent. It is important to differentiate carcinomas of the maxillary sinus breaking through the palate and involving the alveolus from those primarily originating on the upper alveolus. Sinus x-rays are indicated to rule out this possibility for any alveolar or hard palate carcinoma. It has been noted that bone invasion occurs in approximately 50% of all cases of squamous cell carcinoma of the alveolus (Whitehouse: Clin Otolaryn 1:45, 1976).

Metastasis from the alveolus occurs most frequently to the submandibular area. The incidence of lymph node metastasis for carcinoma of the dental alveolus is approximately 35%.

Survival rates in alveolar carcinoma are in the range of 50% 5-year survival. There has been no difference between the upper and lower jaw. Lymph node metastasis at this site, as well as other sites in the oral cavity, considerably lowers the 5-year survival rates to 35% or below.

Surgical therapy is generally recommended for lesions in the T1 or T2 category. Larger lesions may well require combination therapy. If the tumor is ulcerated and involves

9 secondary infection we find resection followed by radiation therapy to be preferable to preoperative radiotherapy.

Carcinoma of the Palate

It is important to note that the hard palate is part of the oral cavity and the soft palate is part of the oropharynx. Perhaps the reason for this is the fact that squamous cell carcinoma of the hard palate is relatively rare. New and Hallburg (Surg Gynecol Obstr 73:520, 1921), in reviewing 5000 cases of cancer of the oral cavity, observed only 25 squamous cell carcinomas of the hard palate. Since this early report the same finding has been noted by many investigators. It has been estimated that for every squamous cell carcinoma of the hard palate there are three or four salivary gland tumors that occur at this site.

Carcinoma of the palate occurs most frequently in the elderly male, and again prognosis is related to tumor size and nodal status. Regional lymph node metastases occur in approximately 50% of the cases. Because they are geographically separated an en bloc resection is not feasible and the neck metastasis must be handled separately from the primary disease itself.

Carcinoma of the Anterior Tongue and Tongue Base

Although the tongue base is located in the oropharynx it will be included in this section to allow consideration of the entire tongue at one time.

The anterior two-thirds of the tongue is the site of two-thirds of all tongue cancers. The other one-third arise in the tongue base. Seventy-five percent of anterior tongue lesions are T2 or smaller, whereas at the tongue base less than 5% of all cancers are T1. Tongue base lesions most frequently present as advanced lesions diagnosed because a neck mass, severe odynophagia, or otalgia has finally led to an examination of the tongue.

The tongue base is associated with clinically palpable neck metastases at presentation in 75% of cases. For carcinomas arising on the anterior two-thirds of the tongue about 33% of these patients will have palpable neck metastases. Metastasis in T1 anterior two-thirds lesions is quite low although Krause et al have pointed out that there is a significant incidence of occult metastases (30%) and avocated treatment of the neck.

The majority of tongue base cancers have clinically positive metastases at presentation. Those that are clinically negative will have a high incidence of occult metastases.

T1 lesions of the anterior tongue can be handled effectively with intraoral excision. Primary closure or a skin graft over the defect will result in a minimal functional deficit. An equally effective treatment would be radiotherapy. However, the length of treatment may make surgery more expeditious. Since occult metastasis is fairly frequent, these patients require careful observation since any neck metastasis that subsequently occurs will require prompt treatment. Combination therapy for all other tongue cancers should be considered.

Tongue base cancers which are T1 can be treated with radiation therapy to achieve the maximum therapeutic benefit with minimal functional deficit. More advanced lesions, when

10 determined to be operable, are best managed by a combined approach of surgery and radiation therapy. The larynx must be sacrificed if it is involved. If not, the tongue base can be resected en bloc with a neck dissection and the tongue base deficit reconstructed with a myocutaneous or other suitable flap to preserve speech and deglutition.

Carcinoma of the Oropharynx

It is important to note that with the revised AJC staging system (1977) the soft palate and tongue base were reclassified as a region of the oropharynx and removed from the oral cavity. The anatomic limits and subdivisions of the oropharynx have been described above.

The majority of malignancies of the oropharynx are squamous cell carcinomas. Less frequent histologies include lymphomas, minor salivary gland malignancies, or the rare melanoma or sarcoma. Today, the histologic terms "transitional cell carcinoma or lymphoepithelioma" are considered to be squamous cell carcinomas of poor differentiation. These histologic variations each account for about 15% of squamous cell carcinomas. Of all upper respiratory tract neoplasms squamous cell carcinoma of the tonsil is second in frequency only to carcinoma of the larynx, according for approximately 12000 new cases a year.

Cure rates for oropharyngeal carcinomas as a group have been somewhat poor. This is attributed to the frequency of metastasis and of advanced local disease at the time of diagnosis. The rate of regional metastasis varies from 40% for the soft palate to 70% for the tongue base. Because of rich lymphatic drainage of this region bilateral metastasis is not unusual. The retropharyngeal nodes are an important depository for metastatic cells and, although the jugulodigastric nodes are the clinically positive nodes more frequently found, the retropharyngeal nodes must be considered in treatment planning. Ballantyne (Am J Surg 108:500, 1964) reported metastases to the retropharyngeal nodes in 44% of pharyngeal wall cancers.

Cure rates for squamous cell carcinomas of the soft palate are in the 50% range as they are more frequently diagnosed early than carcinoma of the tonsil, where the overall cure rate is in the range of 35% (Givens et al: Arch Otolaryngol 107:730, 1981). Jesse and Sugarbaker (Am J Surg 132:435, 1976) assessed the reason for treatment failure (inadequate resection or radiation failure) to be the most important cause of failure. This was followed by regional recurrence. Approximately 10% of their patients failed because of distant metastases. Perhaps more important is the observation by Givens et al who found that, in their series of cancers of the tonsil, 21% of 113 patients died of a noncancerous intercurrent disease within 5 years - often after good control of their tonsil carcinoma had been obtained. They also noted that 27% of their patients developed a second primary cancer whereas Jesse and Sugarbaker found 37% of their patients developed a second primary lesion.

No single treatment has gained popularity. Physicans advocate surgery alone, radical radiation, or combined therapy. A review of the literature would suggest radiation therapy is the treatment of choice in stage I and II disease (Fletcher GH: Head and Neck Surg 1:441, 1979; Doyle PJ et al: Otolaryngol 7:189, 1978). Because of the significant incidence of occult cervical metastasis (Barrs et al: Arch Otolaryngol 105:479, 1979; Sako et al: Surg

11 Gynecol Obstet 118:989, 1964) even in early-staged disease, the radiation field should include the primary lesion and the neck as well.

For stage III and IV operable carcinomas, combination therapy with high-dose preoperative radiation therapy (4500-5000 rad) appears to offer increased local and regional control rates over single treatment modalities (Hamberger and Fletcher: Radiology 119:433, 1976; Doyle PJ et al: Otolaryngol 7:189, 1978; Edstrom S et al: Laryngoscope 88: 1019, 1978).

It is clear that the frequent failure of the above-mentioned treatment plans indicates the need to explore the benefits of adjuvant or systemic therapy.

Methods of surgical approaches with which to be familiar include:

1. Intraoral excision. 2. Resection through mandibular osteotomy. 3. Midline translingual pharyngotomy. 4. Extended lateral pharyngotomy. 5. Transhyoid pharyngotomy. 6. Mandibular swing. 7. Standard composite resection.

Carcinoma of the Hypopharynx

This anatomic region when involved by cancer does not give rise to symptoms until late in the course of the disease. As a result of this fact and the high incidence of metastasis early in the course of the disease, survival rates for carcinoma of the hypopharynx are perhaps the lowest of all sites in the head and neck.

Almost all malignancies arising in this region are squamous cell carcinomas. A history of excess use of tobacco or alcohol is commonly associated with these malignancies. The Plummer-Vinson syndrome, characterized clinically by achlorhydria, sideropenic anemia, and atrophy of the mucous membranes of the mouth, pharynx, and esophagus, is frequently associated with carcinoma of the hypopharynx, oral cavity, or esophagus in women (Ahlborn H.E.: Br Med J 2:331, 1936).

The pyriform sinus is the most frequently involved site in the hypopharynx. Postcricoid and posterior hypopharyngeal wall carcinomas account for only one-third of hypopharyngeal cancers.

Cervical node metastasis is frequent, occurring in 70% of pyriform sinus lesions, 40% of postcricoid carcinomas, and 50% of posterior hypopharyngeal wall lesions (Bryce D.P.: In: Cancer of the Head and Neck. Conley J (ed), 1967, pp 341-346; Truluck and Putney: Arch Otolaryngol 93:271, 1971).

The most frequently proposed therapy for these tumors has been laryngo- pharyngectomy and a neck dissection. When the postcricoid or cervical esophagus is involved a partial esophagectomy is also necessary. Radiation therapy as a solitary treatment modality

12 has been used only for the very small lesions. Radiation therapy has had its use in this group of tumors as an adjuvant therapy. Its best use has been in high doses since low-dose therapy (less than 4000 rad) seems to offer little benefit over surgery alone (Shah et al Am J Surg 132:439, 1976). The use of high-dose preoperative radiotherapy was encouraging (Bryce D.P.: Can Med Assoc J 93:1147, 1965) but the report by Eisbach and Krause (Laryngoscope 87:1904, 1977) was discouraging in that they found that patients treated with high-dose preoperative radiation did no better than those treated by surgery alone. They interpreted their data as indicating that preoperative radiation reduced the tumor size but, in doing so, distorted the apparent extent of disease. They proposed that this resulted in inadequate surgical excision. Their findings have been supported by Martin and co-workers (Cancer 46:1974, 1980) and by Donald and colleagues (Otolaryngol Head Neck Surg 88:738, 1980). These authors suggest that radiation therapy is of value, but that it is best employed postoperatively after adequate resection of the carcinoma without distortion by preoperative radiation therapy. Donald et al in a small group of patients with carcinoma of the pyriform sinus, reported a 28% survival in patients receiving preoperative high-dose radiation, but a 64% survival in patients receiving postoperative radiation.

Postcricoid carcinoma seems to carry the worst prognosis of all hypopharyngeal sites (Som M and Nussbaum M: Otolaryngol Clin N Am 2:631, 1969). Som felt these lesions were best managed by surgery. Problems with managing disease at this site include skip areas along the esophagus and involvement of mediastinal nodes. Since the defect is significant, reconstruction with tubed pedicle flaps or gastric pull-up is indicated.

Posterior pharyngeal wall carcinomas can be surgically resected providing they are not fixed to the prevertebral fascia. Sometimes, this is a difficult clinical distinction to make. Five-year cure rates of 21% have been quoted by Cunningham and Cathen (Cancer 20:1859, 1967). For cancers confined to the posterolateral wall an extended lateral pharyngectomy with primary closure and postoperative radiation therapy has been successfully employed.

Carcinoma of the Nasopharynx

Carcinoma of the nasopharynx is one of the more interesting sites to study in the head and neck region. Cancers at this site have been noted to have a genetic predisposition, particularly in the Chinese where the HLA-A2 and HLA-8-sin2 antigens are associated with cancer at this site (Ho JHC: Int J Radiol Oncol Biol Phys 4:181, 1978). The joint occurrence of these two antigens in a patient increases the risk of the subsequent development of nasopharyngeal carcinoma. In the non-Chinese population it has been suggested that an antigen at the A3 locus might be associated with increased incidence.

Antibodies to Epstein-Baww virus (EBV) has been well established in nasopharyngeal carcinomas. This association extends beyond ethnic boundaries. The unanswered question is whether or not the virus is related to the etiology of this cancer. The use of IgG and IgA antibodies to EBV have been useful to monitor the course of the disease. IgA antibodies to the EBV-viral capsid antigen appear to be the most sensitive marker (Matthews et al: Otolaryngol Head Neck Surg 88:52, 1980).

In the USA nasopharyngeal carcinoma ranks 33rd in prevalence of malignant tumors in males, while in Singapore it ranks first (Muir CS: JAMA 220:393, 1972). In China and

13 Hong Kong this disease has a peak incidence between 45-55 years of age. In non-Oriental patients the disease is bimodal in presentation with a significant prevalence (18%) in patients under age 30, as well as its prevalence later in life. (Deutsch M et al: Cancer 41:1128, 1978).

The WHO has defined three histologic classes of nasopharyngeal carcinomas. These are: (1) undifferentiated carcinoma, (2) nonkeratinizing carcinoma, and (3) squamous cell carcinoma. The undifferentiated carcinomas may be divided into lymphoepitheliomas and lymphopenic types. When lymphocytes occur in a carcinoma of the nasopharynx it is important to realize that they are not neoplastic. They can be found in all three histologic types but most frequently appear with the undifferentiated type. (Batsakis JG: Head Neck Surg 3:511, 1981). The lymphoepithelioma appears to be more sensitive to radiation therapy.

These carcinomas originate most frequently in the posterolateral wall of the nasopharynx. The position of this tumor along the skull base allows for spread by direct infiltration. One particularly devastating direction is through the foramen lacerum to involve the middle cranial fossa and cavernous sinus where cranial nerves III, IV, V, and VI can become involved. The V cranial nerve is the most frequently involved. Metastasis to the cervical lymph nodes is the common presenting symptom in nasopharyngeal carcinoma. Other symptoms of nasopharyngeal carcinoma include epistaxis, hearing loss as a result of eustachian tube obstruction, and facial and head pain.

The treatment of choice for all nasopharyngeal carcinomas is radiation. Surgery is impractical because of the inaccessibility to this region. Bloc resection of the nasopharynx is not practical at the present time. Radical neck dissection is of value to control residual neck nodes if the primary lesion is controlled by radiation therapy. Fortunately, radiation therapy appears to be reasonably effective in controlling this cancer. Five-year survival rates, when combining all states of the disease, are in the 35-40% range (Choa G: In: Cancer of the Head and Neck. Suen JY and Myers EN (eds) 1981 pp 409-411).

14 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 19: Carcinoma of the Larynx, Ear, and Paranasal Sinuses

Carcinoma of the Larynx

Incidence

Cancer of the larynx represents less than 2% of all carcinomas. Squamous cell carcinomas comprise 95-98% of all malignant neoplasms of the larynx. In this regard the American Cancer Society estimates approximately 10.900 new patients with laryngeal cancer annually; with 9100 male and 1800 female new cases for 1982. At the time of diagnosis 62% will have local disease, 26% regional disease, and 8% distant disease. The estimated death rate is 3100 males and 600 females annually. There appears to be no racial tendency although the incidence is considerably higher in males (5:1), heavy smokers, and alcohol consumers. Epidermoid carcinoma of the larynx may be experimentally produced in hamsters exposed to chronic cigarette smoke inhalation.

Diagnosis

There are six methods of examining the larynx and no laryngeal examination, where disease is suspected, is complete unless five of these are used. They are: (1) palpation of the cervical soft tissues, laryngeal cartilage, and base of tongue; (2) indirect mirror examination of the larynx; (3) direct laryngoscopy and biopsy; (4) plain radiography of the neck and chest; (5) specialized radiologic tests - polytomography, xeroradiography, laminography, and computed axial tomographic (CAT) scanning of the larynx; and (6) laryngography - contrast study of the larynx.

Clinical diagnosis usually is made by mirror examination. Laryngeal tomography may be helpful in assessing limited portions of the larynx such as the true cords and immediate subglottic space. Xeroradiography may provide similar limited information. When airway obstruction is threatened by tumor size, contrast laryngography, which provides more comprehensive examination, may be hazardous and therefore contraindicated. Nevertheless, when possible, laryngography may provide an excellent demonstration of difficult-to-examine areas such as the laryngeal surface of the epiglottis at the anterior commissure and subglottic tumor extension. During laryngography the modified Valsalva's maneuver will facilitate examination of the pyriform sinuses, whereas the Müller's maneuver (reverse EE) will aid in evaluating the ventricles of Morgagni by drawing the true cords subglottically, thus dilating the ventricular mucosa. The subglottic arches also may be evaluated by this technique which provides additional opportunity to assess vocal cord mobility on deep inspiration and phonation. Laryngography should generally precede direct laryngoscopy and biopsy since surgical defects or reactive edema produced by the latter render radiologic interpretation difficult if not impossible.

1 Symptoms

Major

1. Hoarseness: It is the cardinal symptom of laryngeal cancer. It is due to inappropriate vocal cord approximation, increased vocal cord bulk, alteration of vibrating properties of the vocal cords, or vocal cord paralysis. Paralysis usually is due to invasion of the vocalis muscles. 2. Dyspnea and stridor: It is a late symptom associated with airway obstruction. The stridor is generally inspiratory and expiratory. 3. Pain can be of two types. One is a vague scratchy sensation in the throat. The other is referred pain to the ipsilateral ear via the vagus nerve. The latter is more common with aryepiglottic fold and pyriform invasion. 4. Dysphagia or difficulty in swallowing is associated with extralaryngeal involvement usually at the base of the tongue, hypopharynx, and supraglottis. 5. Odynophagia or painful swallowing is associated with invasion of the extralaryngeal musculature. 6. Chronic cough and haemoptysis are signs of large fungating tumors, hypopharyngeal invasion, overflow of secretions, or superior laryngeal nerve paralysis.

Minor

1. Weight loss: Due to poor nutrition. 2. Halitosis: Due to necrosing tumor. 3. Mass in the neck: Metastatic lymph node. 4. Laryngeal tenderness: Tumor necrosis or suppuration.

Signs

Signs of laryngeal carcinoma can be divided into two groups: (1) those which are found on neck examination, and (2) those which are seen by visualization of the larynx.

Neck Examination

These are nonspecific signs which occur late in the course of the disease:

1. Lump in neck - metastatic lymph node. 2. Broadening of the larynx on palpation denotes tumor extension to the thyroid cartilage and inner perichondrium and extensive invasion of the larynx. 3. Tenderness of larynx denotes tumor invasion of inner perichondrium and cartilage or laryngeal chondritis secondary to tumor invasion. 4. Loss of crepitation on side-to-side movement of the larynx implies postcricoid tumor invasion. 5. Fullness of cricothyroid membrane to palpation denotes subglottic and usually extralaryngeal tumor extension. 6. Fullness in the thyroid membrane implies tumor invasion of the preepiglottic space, base of the epiglottis, and probably extralaryngeal tumor extension.

2 7. Digital palpation of the base of the tongue may show induration and submucosal tumor extension into the vallecula and base of the tongue.

Laryngeal Examination

The gross appearance of squamous cell cancer of the larynx varies greatly with size and location.

1. Supraglottis: Tumors in this region are often fungating with heaped-up edges and multiple areas of central ulceration. 2. Glottis: The characteristic lesion has a whitish "cauliflower" appearance which is friable to palpation and is surrounded by an area of hyperemia. Glottic lesions tend to be proliferative rather than ulcerating. 3. Subglottis: Tumors in this area are more diffuse and have superficial ulceration. 4. Marginal lesions: Tumors in this area are proliferative, and tend to be fungating with smal central ulcerations and heaped-up margins. 5. Pyriform tumors: These are larger bulky tumors which are not ulcerated. They have heaped-up margins and appear dark red and fleshy.

Anatomic Classification

The larynx is divided into three regions and these may be subdivided into a number of sites as shown in Fig. 19-1.

1. Supraglottis: Tip of epiglottis including its free borders to and including the false cords, and laryngeal ventricles. 2. Glottis: Floor of ventricle including the true cord, 1 cm infraglottic from the edge of the true cord including the anterior and posterior commissure. 3. Infraglottic: Arise 10 mm below the free edge of the vocal cord to the inferior border of the cricoid cartilage. 4. Transglottic: Lesions that cross the ventricle or involve the larynx above and below the true cords, and extend 10 mm below the free edge of the true vocal cord.

Associated Regions

1. Marginal: Lesions involving the aryepiglottic folds. 2. Superior hypopharynx: a. Vallecula: Vallecula surface of epiglottis, base of tongue posterior to circumvallate papilla and medial to glossoepiglottic folds. b. Posterior pharyngeal wall: Zone between posterior projection of the tip of the epiglottis and inferior border of cricoid. 3. Inferior hypopharynx: a. Pyriform sinus: An area bounded superiorly by the glossoepiglottic fold, inferiorly by the apex of the pyriform sinus, laterally by the thyroid cartilage, and medially by the aryepiglottic fold and arytenoid cartilage. b. Postcricoid: Mucosal area covering the rostrum of the cricoid cartilage.

3 The Biopsy

One cubic centimeter of tissue contains 109 cells. In general a carcinoma is detectable palpably when it attains a diameter of 1 cm. Therefore 109 cells/cc must be malignant to allow gross detection. Histopathologic detection is possible when 106 cells/cc (1:1000) are malignant. A lesser ratio of malignant to normal cells per cubic centimeter of tissue go entirely unnoticed histopathologically, emphasizing the occasional difficulty in obtaining histologic confirmation of cancer.

Treatment Modalities

Before deciding on the mode of treatment, it is well to note that, in good hands, the mortality for laryngectomy with radical neck dissection varies from 2-5%. The risk is higher after the patient has received radiotherapy. MacComb reported that the mortality of all composite resections about the head and neck is 4.4% without preoperative irradiation and 8.5% after preoperative irradiation. We do not intend to promote any specific mode of therapy. To date, surgery, radiotherapy, and combined therapy are the therapeutic modalities of choice.

TNM Classification and Staging - Definitions:

(American Joint Committee on Cancer Staging and End Results Reporting, 1980)

TNM Classification

Primary Tumor (T)

Tx Tumor that cannot be assessed by rules. T0 No evidence of primary tumor.

Supraglottis

Tis Carcinoma in situ. T1 Tumor confined to site of origin with normal mobility. T2 Tumor involving adjacent supraglottic site(s) or glottis without fixation. T3 Tumor limited to larynx with fixation and/or extension to involve postcricoid area, medial wall of pyriform sinus, or pre-epiglottic space.

T4 Massive tumor extended beyond the larynx to involve oropharynx, soft tissues of neck, or destruction of thyroid cartilage.

Glottis

Tis Carcinoma in situ. T1 Tumor confined to vocal cord(s) with normal mobility (including involvement of anterior or posterior commissures). T2 Supraglottic and/or subglottic extension of tumor with normal or impaired cord mobility.

4 T3 Tumor confined to the larynx with cord fixation. T4 Massive tumor with thyroid cartilage destruction and/or extension beyond the confines of the larynx.

Subglottic

Tis Carcinoma in situ. T1 Tumor confined to the subglottic region. T2 Tumor extension to vocal cords with normal or impaired cord mobility. T3 Tumor confined to larynx with cord fixation. T4 Massive tumor with cartilage destruction or extension beyond the confines of the larynx, or both.

Nodal Involvement (N)

Nx Nodes cannot be assessed. N0 No clinically positive node. N1 Single clinically positive homolateral node 3 cm or less in diameter. N2 Single clinically positive homolateral node more than 3 cm but not more than 6 cm in diameter, or multiple clinically positive homolateral nodes, none more than 6 cm in diameter. N2a Single clinically positive homolateral node more than 3 cm but not more than 6 cm in diameter. N2b Multiple clinically positive homolateral nodes, none more than 6 cm in diameter. N3 Massive homolateral node(s), bilateral nodes, or contralateral node(s).

N3a Clinically positive homolateral node(s), one more than 6 cm in diameter. N3b Bilateral clinically positive nodes (in this situation, each side of the neck should be staged separately; that is, N3b: right, N2a; left, N1). N3c Contralateral clinically positive node(s) only.

Distant Metastasis (M)

Mx Not assessed. M0 No (known) distant metastasis. M1 Distant metastasis present Specify.

Stage Grouping

Stage I T1N0, M0 Stage II T2N0, M0 Stage III T3N0, M0 T1-3N1, M0 Stage IV T4N0, M0 Any T N2-3, M0 Any T, any N, M1.

5 Five-Year Survival by 1972 TNM Classification

The American Joint Committee for Cancer Staging published in July 1972 the following 5-year survival rates on 1632 laryngeal carcinoma, 1061 of which were of glottic origin, 552 supraglottic, 19 subglottic, and one of unknown site of origin (Table 19-1). It would appear that in large series, radiation produces comparable results to surgery when the tumor is small but appears at a disadvantage as tumor size increases. The pool of radiation successes in this combined series is even smaller than indicated when survival rates are corrected for surgical salvage following radiation failure.

Vermund's 1969 series is corrected for the 1972 re-classification. His 5-year survival statistics appear in Table 19.2.

Table 19-1. Five-Year Survival by 1972 TNM Classification

N0 N1a N1b N2b N3 M Glottic Supra Glottic Supra Glottic Supra Glottic Supra

T1a 94% 86% 61% 65% 100% 45% No cases T1b 93% 94% (Only 1 case) T2 85% 82% 62% 45% (no case) 20% (No case) 0% (1 case) T3 65% 76% 53% 36% 0% 20% No cases (4 cases) T4 40% 55% 37% 40% 10% 8% 0% No cases (2 cases).

Table 19-2. Laryngeal Carcinoma Five-Year Survival in Relation to Treatment Modalities

Tumor Radiation and Surgical Salvage Surgery

Glottic T1 86% 65% T2 55 69% T3 29% 55% T4 14% 35%

Supraglottic T1 73% 71% T2 44% 62% T3 29% 55% T4 10% 56%

Subglottic T1-4 36% 42%.

6 Conservation Surgery

1. According to Som the indication for horizontal supraglottic laryngectomy is a tumor limited to the supraglottic region 3-5 mm from the anterior commissure with normal vocal cord mobility. Contraindications are involvement of the vallecula, arytenoid, or pyriform fossa. On the other hand, the criteria proposed by Sisson include:

a. A margin of 5 mm must exist between the inferior border of the tumor and the anterior commissure. b. The true vocal cords must be mobile. c. Only one arytenoid can be removed. d. There is no clinical or x-ray evidence of extension into the thyroid cartilage. (Theoretically, supraglottic lesions should not involve the thyroid cartilage). e. There is no evidence of anterior neck invasion. Induration and the presence of enlarged nodes in the suprahyoid space or the thyrohyoid membrane are contraindications to conservation surgery. f. In the case of tongue lesions there must not be fixation of the tongue or extension on the lingual surface to within 5 mm of the circumvallate papillae or foramen caecum. g. There must be no extension to either the postcricoid or the interarytenoid space. Prevertebral fascia fixation is a contraindication. h. Laryngograms and direct endoscopy must prove the apex of the pyriform sinus to be free of disease. i. Generally, a lesion over 3 cm in diameter or fixed cervical nodes are contraindications to partial resection. j. Relatively normal pulmonary function. k. Under age 60-65.

2. Indications for vertical hemilaryngectomy in non-radiated tumors of the true cord are: (a) at least one vocal cord or arytenoid must be mobile; (b) less than 30% involvement of the anterior contralateral cord. Contraindications are: (a) superior involvement of the ventricle or false cord; (b) subglottic extension greater than 10 mm anteriorly. Vertical hemilaryngectomy may be used successfully in salvage of radiation failures of tumors involving the membranous true cord providing strict criteria are met. Contraindications to this procedure in radiated tumors of the true cord are therefore: (a) any contralateral cord involvement; (b) greater than 10 mm anterior subglottic extension; (c) bilateral cord fixation.

3. Indications for anterior commissure technique are: (a) horseshoe lesions of the membranous vocal cords crossing the anterior commissure; (b) less than 10 mm anterior subglottic extension; (c) no arytenoid involvement; (d) normal vocal mobility of at least one vocal cord or arytenoid.

Discussion of Specialized Areas

Glottis

Anterior Commissure. Anterior commissure lesions per se are rare and should not be categorized with cordal tumors that cross the midline anterior commissure. Radiation therapy provides 80% survival rates or 40% 5-year cure rates according to Kirchner who therefore

7 concludes radiation to be a relatively ineffective treatment modality in this situation. Som provides a 68% surgical cure rate by anterior commissure technique and 81% overall cure rate produced by further salvage surgery.

Ogura noted that 1% of glottic lesions are pure anterior commissure lesions and 30% are glottic tumors which extend into the anterior commissure. Thirty-one percent had greater than 5 mm subglottic extension and 8% had positive lymph node metastasis. The absolute overall survival was 74% for conservation surgery, 62% for total laryngectomy, and 61% for radiation. Survival by stage was stage I, 83%; stage II, 74%; and stage III and IV, 62%. Most of the recurrences (34%) occurred in the neck. Local recurrences was 1%.

Hemilaryngectomy. The overall survival for patients treated with hemilaryngectomy is 91% (primary cure and salvage). The survival by stage is as follows: stage I, 87%; stage II, 82%; stage III, 74%. The salvage rate by surgery and irradiation is 74%. In the most recent series of 111 cases, the survival is 90% for primary surgery, 64% salvage rate, and overall survival is 96%.

Tumor extension into the arytenoid area on one side did not affect survival. In 79 cases the overall cure rate is 90%. Glottic carcinoma with subglottic extension occurs in 20% of the cases. The survival depends upon the length of the subglottic extension. Stage II lesions with less than 10 mm extension have a cure rate of 92%. Stage II and III lesions with more than 10 mm extension have a cure rate of 69% and 50% respectively. The overall cure rate for surgery is 83% and for radiation 63%.

Total Laryngectomy. The overall survival for the combined total laryngectomy and irradiation group is 70%: with stage I, 95%; stage II, 69%; stage III, 68%; stage IV, 45%. The salvage rate for irradiation is 51% for an overall cure rate of 80%.

Radiation for Early Lesions. The use of radiotherapy has the following cure rates shown in Table 19-3.

Table 19-3. Reported Cure Rates Following Radiotherapy for Laryngeal Carcinoma

Study T1 T2 Overall Primary Therapy and Salvage

Perez et al 82% 77% 62% Horiot et al 90.5% 86% Goepfert et al 88% 74% Wang et al 90% 80% (membranous cord 92%, anterior commissure 82%, arytenoid 76%, vc fixation 63%) Stewart et al 95% 72% (T3 50%, T4 25%) Hibbs et al - 76% Boles et al - 74% Lederman et al - 65%.

Carcinoma in Situ. According to A. Miller carcinoma in situ carries a 15% probability of invasive change within 3-8 months. Vocal cord stripping, the initial treatment of choice, provides 75% cure rate. Hemilaryngectomy is recommended for recurrent carcinoma in situ.

8 Irradiation as the initial treatment is contraindicated because it carries the highest rate of recurrence and invasion.

Verrucous Carcinoma. This carcinoma is characterized by an exophytic warty appearance, slow growth, local invasion, scarcity of metastases, and a benign histology. Biller et al reported 15 cases of this variant of squamous cell carcinoma. They advocated adequate but conservative surgical excision as opposed to radical radiation therapy.

Supraglottic Lesions

A 3-year determinate cure rate for supraglottic tumors is: stage I, 82.5%; stage II, 79%; stage III, 69%; stage IV, 50%. The overall cure rate is 76%. The salvage rate by other modalities is 47%. The overall survival is 82% for conservation surgery.

The 3-year determinate survival for large T3 and T4 lesions with combined total laryngectomy and neck dissection and radiation is 66%. Those treated by irradiation alone is 33%. The 5-year survival after total laryngectomy only is 45-60%, and full-course radiation only is 7-56% with an average of 20% on review of the literature.

Transglottic Carcinoma

According to Wang transglottic carcinoma carries a 24% 5-year survival by radiation therapy alone and 53% 5-year survival rate when treated by total laryngectomy.

Aryepiglottic Fold Carcinoma

The overall 3-year determinate survival is 53%. The survival by stage is: stage I, 66%; stage II, 50%; stage III, 52%; stage IV, 28%. Smaller lesions treated by partial laryngopharyngectomy had a 59% and larger lesions 27% 3-year survival.

Pyriform Sinus Carcinoma

This carcinoma is rightfully a hypopharyngeal lesion but so often invades the laryngeal framework that its respiratory symptoms, hoarseness, aspiration, and pain justify its brief discussion in this chapter. The 3-year overall cure rate is 40%. When metastases are present the cure rate drops to 34%. If there are no positive lymph nodes the cure rate is 48%. With bilateral neck metastasis, the cure rate is 17%. The 3-year cure rate by stage is as follows: stage I, 66%; stage II, 65%; stage III, 40%; stage IV, 30%. The cure rate by irradiation is 40%. The main cause for therapeutic failure is persistent neck disease. Once lymph node metastases are present the cure rate drops to below 35%.

Treatment of Nodal Metastasis

There is little disagreement that radical neck dissection is of value in the treatment of the clinically palpable node. However, elective neck dissection remains a controversial issue. The procedure is generally justified when the incidence of occult metastasis for any given tumor approaches 25%. The kind of data that may be helpful in the preoperative decision making process is therefore based on histologic examination of neck specimens in large series.

9 Incidence of Nodal Metastasis

A. Norris

Epiglottic 42% False cord 29% True cord 6% Subglottic 16%

B. McGavran

Supraglottic 33% Transglottic 52% Subglottic 19%.

On the other hand, others might argue that there is in fact no statistical evidence for improved survival rates by elective neck dissection over that performed subsequent to the emergence of a palpable node. Furthermore, there is growing evidence that radiotherapy alone may be effective in controlling occult regional metastases. Bagshaw suggests a 27% 5-year control rate for N2, N3 adenopathy and in this regard a 95% 5-year control rate for occult metastasis.

Node fixation is universally an ominous sign. Here radical neck dissection according to Santos provides no substantial role in improving survival in such patients. The effectiveness of standard radical neck dissection is equally questionable when node involvement occurs in the posterior cervical triangle or along the paratracheal chain, the latter notably resulting from a subglottic primary. In this instance Harrison recommends thyroid lobectomy and superior mediastinal dissection of the paratracheal lymphatics.

Neoplasms of the Ear

The majority of ear malignancies involve the auricle (85%) while 10% of such malignancies involve the external auditory canal and only 5% involve the middle ear and mastoid.

Symptoms and Signs

The earliest symptoms of carcinoma of the external auditory canal is otorrhea with pain (50%). The pain is intense and is out of proportion to the pathologic and clinical findings. Other symptoms include bleeding, fullness in the ear, and a conductive hearing loss (29%). The major findings include a vascular friable polyp or ulceration of the posterior and inferior wall of the external auditory canal. Later symptoms include perceptive deafness (15%), vertigo (13%), and facial nerve paralysis (13-35%). The incidence of metastasis at initial presentation is 13-30%.

10 External Ear

Most tumors of the external ear are squamous cell carcinoma. The incidence is one case in 16,000 ear complaints. In Conley's series, 62% were squamous cell and 31% were basal cell epitheliomas. The treatment for basal cell carcinoma of the auricle is wide excision. Miller advocates en bloc resection of most of the auricle with the underlying mastoid cortex when cancer (basal cell or squamous cell) lies within 1 cm of the external meatus. Squamous cell carcinoma of the helix can be resected widely and primarily reconstructed. Within the canal, the posterior canal wall near the annulus is a common site of malignancy. The lymphatics of this area drain in the direction of the preauricular, mastoid, subparotid, and subdigastric nodes. Lesions of the external auditory canal, particularly of the bony canal, should be treated with "superficial" temporal bone resection leaving intact the facial nerve and the labyrinth. The prognosis for helical and antihelical lesions (squamous cell as well as basal cell) is 90-95% 5-year survival. Lesions near the concha and those of the external auditory canal have a 5-year survival rate of about 30-40%. Lesions that invade the middle ear or produce facial nerve paralysis have a cure rate of less than 25%. Lesions of the anterior canal may metastasize to the pretragal or parotid nodes through the fissures of Santorini. In general, surgical resection provides a better prognosis than radiotherapy. En bloc radical neck dissection is not necessary in the absence of clinically palpable nodes. If the parotid region is involved, en bloc parotidectomy is to be performed.

Middle Ear Mastoid

The most common tumor of the middle ear is squamous cell carcinoma while glomus jugulare tumor ranks second in prevalence. The most common sarcoma of the middle ear is embryonal rhabdomyosarcoma. Adenoidcystic carcinoma is rare. It is derived from the ceruminous gland duct epithelium of the posterior meatus.

Symptoms of Malignancy

1. Deep, unremitting pain due to invasion of bone by the tumor. 2. Bleeding from the external auditory canal may be the first and only symptom of the disease. 3. Hearing loss may be of the conductive type if the tumor obstructs the external auditory canal or destroys the middle ear transformer mechanism. Perceptive hearing loss may result if the inner ear is progressively involved. 4. Vertigo may indicate inner ear destruction. 5. Facial nerve paralysis may occur when disease extends medially to involve the middle and inner ear. 6. Therefore, the only symptom that differentiates carcinoma from chronic otitis media or cholesteatoma is pain, and its presence should alert the physician to possible malignancy.

Diagnosis

Routine mastoid and skull films show bone destruction in 40% of the patients. Anteroposterior and lateral polytomography are helpful in delineating the extent of bone erosion. Carotid angiography is essential when dural involvement is suspected.

11 Treatment

Early attempts to treat cancer of the temporal bone consisted of radical mastoidectomy followed by radiation therapy which resulted in a 5-year cure rate of less than 25%. Osteoradionecrosis and radiation injury to the brain stem often brought devastating sequelae. Temporal bone resection has increased the 5-year cure rate to 36-44%. Preoperative radiation should be used cautiously especially when dural involvement is present since the incidence of CSF leaks and meningitis greatly increases when dural grafting follows radiation therapy. In this regard, when the dura is involved with carcinoma, radiation used postoperatively avoids life-threatening complications of the dural graft repair.

Lesions involving the middle ear therefore call for subtotal temporal bone resection, a method which Montgomery beautifully describes. Hilding in 1967 described an approach for total resection of the temporal bone. In this regard the facial nerve is sacrificed, a total parotidectomy is performed, and a facial to hypoglossal anastomosis is recommended. Radical neck dissection is recommended when clinical adenopathy is present.

Carcinoma of tghe Paranasal Sinuses

Cancer of the paranasal sinuses is relatively rare. According to Martin malignancies here represent 0.2% of all cancer and 3% of cancer of the upper respiratory tract. Carcinoma of the maxillary sinus constitutes 80% of sinus malignancies and has been linked to previous diagnostic introduction of thorium oxide (Thorotrast) contrast medium into the sinus cavities.

Maxillary Sinus

This is the largest paranasal sinus. Its boundaries are:

1. Medial wall: Nose. 2. Apex: Zygoma. 3. Anterior: Face. 4. Posterolateral: Infratemporal fossa. 5. Posteromedial: Pterygopalatine fossa. 6. Roof: Orbit. 7. Floor: Alveolar process of the maxilla which holds the three molars and the second premolar. In the adult, the floor of the maxillary sinus is lower than that of the nose, whereas in a child the reverse is true.

Tabb and Barranco reported a male/female ratio of 2:1 with an age distribution greatest in the sixth and seventh decades of life. No racial tendency is reported.

The earliest sign of cancer involving the antrum of Hihgmore is unilateral nasal obstruction. This is associated with ipsilateral nasal discharge which may be purulent. The next most common symptom is cheek or palate swelling. Nasal bleeding is less commonly encountered. Hypesthesia in the distribution of the infraorbital nerve is an ominous sign which indicates a high and often posterior lesion. Trismus is a sign of pterygoid involvement and ophthalmoplegia points to orbital or intracranial extension.

12 Most topographic classifications of tumors of the maxillary sinus are based on Ohngren's line, an imaginary line drawn diagonally through the maxillary sinus seen on lateral projection from the inner canthus to the mandibular angle. Tumors anterior to this line share a better prognosis (71% 3-year survival) as opposed to a tumor posterior to this line (28% 3- year survival). It is an established fact that tumors lying posteriorly are much more lethal by virtue of their ability to gain access to the anterior cranial fossa through the cribriform plate and into the middle cranial fossa via the foramen rotundum. The AJCC (1980) has staged and classified the maxillary sinus tumors in the following way:

The TNM Classification and Staging: Definitions

(American Joint Committee on Cancer Staging and End Results Reporting 1980)

TNM Classification

Primary Tumor (T)

Tx Tumor that cannot be assessed by rules. T0 No evidence of primary tumor. T1 Tumor confined to the antral mucosa of the infrastructure with no bone erosion or destruction. T2 Tumor confined to the suprastructure mucosa without bone destruction, or to the infrastructure with destruction of medial or inferior bony walls only. T3 More extensive tumor invading skin of cheek, orbit, anterior ethmoid sinuses, or pterygoid muscle. T4 Massive tumor with invasion of cribriform plate, posterior ethmoids, sphenoid, nasopharynx, pterygoid plates, or base of skull.

Nodal Involvement (N)

Nx Nodes cannot be assessed. N0 No clinically positive node. N1 Single clinically positive homolateral node 3 cm or less in diameter. N2 Single clinically positive homolateral node more than 3 cm but not more than 6 cm in diameter or multiple clinically positive homolateral nodes, none more than 6 cm in diameter. N2a Single clinically positive homolateral node more than 3 cm but not more than 6 cmin diameter. N2b Multiple clinically positive homolateral nodes, none more than 6 cm in diameter. N3 Massive homolateral node(s), bilateral nodes, or contralateral node(s). N3a Clinically positive homolateral node(s), one more than 6 cm in diameter. N3b Bilateral clinically positive nodes (in this situation, each side of the neck should be staged separately; that is, N3b; right, N2a; left, N1). N3c Contralateral clinically positive node(s) only.

13 Distant Metastasis (M)

Mx Not assessed. M0 No (known) distant metastasis. M1 Distant metastasis present. Specify.

Stage Grouping

Stage I T1N0; M0 Stage II T2N0; M0 Stage III T3N0; M0 T1 or T2 or T3N1; M0 Stage IV T4N0 or N1; M0 Any TN2 or N3; M0 Any T, any N; M1.

The treatment of choice for maxillary sinus malignancy is en bloc resection of the maxilla including the ethmoid sinus and lateral nasal wall. If indicated, the orbital contents, frontal sinus, and cribriform plate also are removed en bloc. Preoperative radiation improves the ability to encompass the tumor by sterilizing its margins and reducing mechanical spillage at the time of surgery. The average 5-year survival rate for maxillary carcinoma treated by radical surgery alone is therefore 62%.

In a recent series of 96 patients Lee and Ogura noted that 69% of patients had primary tumor control with combined radiation and surgery and 14% with radiation alone. The overall cure rate was 49%. Tumor recurrence was found in 20% of the cases in the neck, 16% at the primary site, and 8% at distant sites. Overall, the 5-year NED survival by stage was T1, 60%; T2, 45%; T3, 28%; and T4, 38%.

A review of the literature indicates that combined therapy gives an overall survival in maxillary cancer of 29-48% and radiotherapy 0-34% (see Table 19-4). Thus the former is the treatment of choice.

Table 19-4. Maxillary Sinus Carcinoma Survival

Study No of Five-Year Surgery and Radiation patients Overall (%) Radiation (%) Alone (%)

Holsti 62/219 28 34 15 Boone 52/121 43 30 44 Badib 48/344 14 29 10 Hamberger 148/591 25 45 19 Lewis 191/677 28 33 20 Cheng 17/50 34 48 22 Lee and Ogura 44/96 49 69 14.

14 The maxillary sinus drains into the retropharyngeal and parapharyngeal nodes. Hence, a routine elective neck dissection is of little benefit. However, if a patient presents with a palpable neck node, neck dissection should be performed although en bloc dissection is not possible.

The following factors should be considered contraindications to radical surgery of the maxillary sinus:

1. Destruction of the base of the skull. 2. Extension of cancer into the nasopharynx. 3. Inoperable regional metastasis. 4. Generalized metastasis. 5. Patient refusal to accept treatment.

Frontal, Ethmoid, and Sphenoid Sinuses

Primary carcinoma of these sinuses is extremely rare. Brownson and Ogura reported five cases of malignancy of the frontal sinus and reviewed the literature for another 28 cases. They concluded that epidermoid carcinoma is the most common form of malignancy in the frontal sinus. The most frequent presenting symptoms are swelling, pain, and proptosis. The prognosis is extremely poor. The surgical approach described in their paper recommended that the dura should be sacrificed when the posterior wall is eroded. The ethmoid sinuses should be resected en bloc. The orbit and the contralateral frontal sinus are to be sacrificed when in doubt as to the margin of invasion.

Carcinoma of the ethmoid has a similarly discouraging prognosis. It is interesting to note that ethmoidal carcinoma is unusually common among woodworkers. Ketcham has recently reported a series of 54 patients who underwent surgical removal of ethmoid sinuses by a combined intracranial transfacial approach resulting in a 56% 5-year survival rate. Advantages of this combined approach were: (1) intracranial tumor extension could be established with certainty; (2) the brain could be adequately protected during tumor mobilization; (3) en bloc removal was possible; (4) CSF fistula could be avoided. Preoperative radiation was not used as an adjuvant to surgical resection because of greatly increased morbidity associated with failures of dural grafts and subsequent cerebrospinal fluid leaks and meningitis. Bridger noted cures in nine of 15 patients after this approach.

Carcinoma of the sphenoid sinus is very rare with unfavourable prognosis. Most tumors invade the sphenoid from the nasopharynx, posterior ethmoid air cells, or via the periorbital tissues. On rare occasions nasal tumors may erode into the sphenoid sinus. Because of the inaccessible anatomic location, complete resection is impossible. Consequently, the treatment of choice is radiotherapy. Clinically palpable nodes can be treated with radiation or radical neck dissection.

15 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 20: Carotid Body Tumor, Hemangioma, Lymphangioma,

Melanoma, Cysts, and Tumors of the Jaws

Carotid Body Tumor

The normal carotid body, situated at the carotid bifurcation, is a chemoreceptor similar to the aortic body. It responds to arterial changes in pH, temperature, oxygen, and carbon dioxide tension. The carotid body is different from the carotid sinus, which is a pressoreceptor.

The carotid body tumor is a nonchromaffin paraganglioma associated with a network of chemoreceptors. It is believed to arise from neurocrest cells. These cells are derived from sympathoblasts rather than from chromaffinoblasts. Other than at the bifurcation of the carotid, such tumors can be found in other chemoreceptors of the head and neck, middle ear, jugular bulb, carotid bulb, base of the skull, lateral pterygoid, vagal, and aortic regions. Unlike the carotid body, most tumors have no demonstrable chemoreceptive or hormonal function. These tumors occur generally in equal frequency in men and women, most commonly in the third and fourth decades of life. The carotid body tumor usually presents as a firm, rubbery, painless, slow-growing mass. When the tumor is large, it may cause a mild pain. Syncopal episodes may occur when the tumor compromises the cerebral blood flow. A bruit is often heard over the tumor. Carotid angiography that shows an "egg shell-like" mass displacing the internal carotid artery laterally and widening the crotch is pathognomonic of this tumor. The major blood supply of this tumor may be from the vertebral artery, the thyrocervical trunk, as well as the carotid arteries.

A familial tendency has been reported by Rush and Chase. Bilateral carotid body tumors have been reported by Rush and Katz.

Tumors of the carotid body are considered radioresistant. Therefore, a symptomatic tumor should be resected. However, an asymptomatic tumor in an elderly patient is best left alone. Carotid body tumor is said to originate from the adventitia of the artery. Consequently, one should be able to free this tumor from the carotid artery. Conley described this tumor as a mass developing in the adventitia of the bifurcation, pushing the internal and external carotid arteries apart. It may eventually encircle both arteries. The weakest point of this encirclement has been determined to be in the posterolateral aspect of the internal carotid artery. Consequently, it is the safest place to begin resection of the tumor. When the internal carotid artery needs to be sacrificed, it would be wise to apply a vascular graft. Sacrificing the internal carotid artery without applying a graft carries a 30-50% mortality with another 40% incidence of neurologic deficits. Nelson in 1962 stated that 5-10% of these tumors are malignant. Regional lymph nodes and distant metastases have been reported. However, Conley indicated that multicentricity of paraganglionic foci in the head and area is not uncommon. It is, therefore, difficult to differentiate metastases from de novo foci.

1 Hemangiomas

Hemangiomas are congenital vascular abnormalities rather than true neoplasms. The most common sites are the face and neck. Approximately, 63% of hemangiomas are cutaneous, 15% subcutaneous, and 22% mixed. The most common site of deep hemangioma in the head and neck is within the masseter muscles. They generally are more prevalent in females in a frequency of 3:1 except for subglottic hemangiomas where the sex ratio is about equal. They may be classified pathologically into three types: capillary, cavernous, and mixed. Pathologic classification is probably of little value, compared to clinical classification. Approximately 75% of hemangiomas are present at birth, while 85% will have manifested themselves by the first year of life. Approximately 3% of the patients have a positive family history.

Hemangiomas of the Skin and Subcutaneous Tissue

Port-Wine Hemangioma

This reddish blue lesion is composed of capillaries with adult endothelium and persists with little change in life. The important features clinicaly are: (1) the lesion grows only in proportion to body growth and will always cover the same percentage of body surface area; and (2) the lesion is not raised above the surrounding skin. This lesion does not respond to radiation and should be treated with surgical excision, tatooing, or cosmetic coverage. Unless absolutely necessary, treatment is not recommended before the age of 2. Hemangiomas that grow rapidly during the first few months of life are also the ones that involute subsequently.

Strawberry Hemangioma

This lesion is raised above the surrounding skin, blanches somewhat on pressure, and has a strawberry red color. It is the most common type, accounting for 90% of all infant hemangiomas. Approximately 90% of these hemangiomas are capillary in type and likewise 80-90% involute by the fifth year.

Excision should not be performed before age 5, unless serious problems ensue (bleeding, blockage of an important orifice, ulceration, thrombocytopenia, etc). Steroid treatment seems promising, and sclerosing agents are occasionally useful.

The embryonal vascular endothelium of strawberry hemangioma is sensitive to irradiation, but even small doses may inhibit facial bone growth with severe sequelae.

Hemangioma of the Parotid Gland

It is the most common tumor of the parotid in infancy. Goldman advocates prompt surgical excision as soon as definite growth is recognized, while others suggest waiting until age 5. Nussbaum et al reported cavernous hemangioma of the salivary gland in five adults. Infantile hemangiomas of the salivary gland are usually of the capillary type.

2 Hemangioma of Bone

This lesion is found in the vertebral bodies, frontal and parietal bones, mandible, or maxilla; in females usually during the fourth decade. Slow progressive swelling is seen clinically, and a characteristic "honeycomb" or "sunburst" appearance is present radiographically. Massive hemorrhage may occur following tooth extraction in a mandible involve with a hemangioma. Surgical excision is the treatment of choice.

Hemangioma of the Larynx

Subglottic Hemangioma of Infancy

The symptoms produced are of a croup-like syndrome with varying degrees of stridor, absence of hoarseness when crying, weight loss, and marked persistent cyanosis. The cyanosis may be worse when the patient is excited or cries. It is usually of the cavernous type and usually located anteriorly. Ninety percent of patients develop symptoms before the age of 3 months, but only 50% have associated subcutaneous hemangiomas.

The diagnosis is made by laryngoscopy and tracheoscopy. Biopsy is generally contraindicated because of the possibility of severe hemorrhage. The treatment is tracheostomy to relieve the airway obstruction. Gradual involution of the hemangioma in 12- 18 months is the usual course. Steroids occasionally seem to promote involution. Radiation is not recommended because of (1) absence of proof that in small doses of 300-600 R any significant histologic effect occurs, (2) possible effects of radiation on the growth and development of the larynx, and (3) the possible cause of thyroid carcinoma years later. Healy advocates CO2 laser to destroy the lesion because of the properties of laser (minimal edema, scarring, and limited bleeding).

Adult Laryngeal Hemangioma

The location is usually supraglottic or glottic and often polypoid or pedunculated in appearance. Adult hemangiomas of the larynx rarely cause respiratory embarrassment and generally should be left untreated.

Hemangioma of Nasal Bone

This is a rare tumor. To date only 15 cases have been reported. This is a benign, slow- growing, painless vascular tumor within the nasal bone. The overlying skin or mucosa can be telangiectatic. Some patients present with epistaxis while others have no bleeding tendency. The radiographic appearance of "soap bubble" texture is pathognomonic. Feeding vessels are usually the facial and internal maxillary arteries. Treatment involves excision with a margin of normal bone.

Hemangiopericytoma

Stout and Murray were the first to accurately describe and name this entity. The capillary pericyte of Zimmermann was the cell of origin of this tumor. It is about equally dsitributed in both sexes. It shows a propensity for the fourth, fifth, and sixth decades.

3 Clinically, it presents as a slowly expanding asymptomatic mass. In bony cavities, pressure pain may be noted. With those in the nose and paranasal sinuses, epistaxis is a frequent complaint. Histologically, it features sheets or a random distribution of ovoid or spindle- shaped cells with indistinct cytoplasm, large nuclei, and rare mitoses. Silver reticulin stain is essential to establish the diagnosis. It is usually considered a malignant lesion with metastatic rates ranging from 35 to 57%. This tumor is radioresistant. Wide excision is the treatment of choice.

Lymphangioma

Lymphangioma is a congenital, benign, unilocular or multilocular, endothelium-lined, fluid-containing swelling of lymphatic origin. In 80% of the cases, the lesion is located in the neck. This condition is present at birth in 65% of the cases and would have manifested itself by age 2 in 90%. When symptomatic, they should be resected to prevent stridor and dysphagia in the infant. Resection should be performed carefully to spare all the vital structures. Lymphangioma has been said to be the most common tumor of the parotid gland in children.

Melanomas of the Head and Neck

Melanocytes are believed to be derived from the neural crest cells that have migrated peripherally to the integument by the twelfth week of gestation. The melanocyte forms the pigment which is then transmitted to the malpighian cells of the basal layer of the skin.

Approximately 20-35% of melanomas occur in the head and neck region. Less than 1% occur intraorally. Conley reports the scalp to be the most frequent site, followed by the face, neck, and ear. Melanoma occurs slightly more frequently in men, except for superficial melanoma of the face which is more common in women. Less than 2% of melanomas occur before puberty. Predisposing etiologic factors are solar exposure, chronic infection, irradiation, friction irritation, thermal burns, and endocrine changes of puberty and pregnancy.

Nevi may be classified into three basic types depending upon the location of the melanocytes.

Junctional Nevus

Melanocytes are present at the dermoepidermal junction. Grossly, it is flat, light to dark brown or black, and non-hairy. Melanoma may arise from junctional nevi, but very rarely before puberty.

Compound Nevus

Melanocytes are present in both the epidermins and dermis. Grossly, it combines the features of a junctional and an intradermal nevus.

4 Intradermal Nevus

Melanocytes are exlusively in the dermis. Grossly, this is the common adult mole and may be papillary, pedunculated, or flat and is usually hairy.

Other varieties of nevi are the (1) Spitz nevus: a dome-shaped benign nevus, generally pink or red, primarily in children, usually measuring less than 1 cm in diameter. (2) Halo necus: a central brown papule surrounded by a pale white circle of depigmentation. The regularity of the circle of depigmentation and benign-looking nevus in the center distinguishes it from melanoma. (3) Blue nevus: appears in infancy or childhood as a small black or dark blue, round dome-shaped hard papule with a smooth surface. These tend to appear on the face and on top of the hands and feet and persist unchanged through life. It is benign. The junctional nevus of childhood gradually matures into a compound and then an intradermal nevus. In pregnancy, new moles often appear and pre-existing one become darker.

Only 25% of melanomas seem to arise from previously benign neci, almost all junctional. Signs of possible malignant change include: deepening pigmentation, spread of pigment beyond the gross confines of the lesion, ulceration, rapid growth, appearance of flat areas of depigmentation in a black mole, inflammation, satellite nodules, bleeding, and the presence of itching.

Melanoma may be classified into three basic types:

Superficial Spreading Melanoma

The surface is elevated, the margins are palpable, and the color variable. The prognosis is intermediate between lentigo maligna melanoma and nodular melanoma.

Lentigo Maligna Melanoma (Melanoma in a Hutchinson's Melanotic Freckle)

Hutchinson's freckle typically occurs on the cheek of elderly patients as a flat, slow- growing brown lesion. Malignant melanoma frequently develops in Hutchinson's melanotic freckle and is characterized by thickening and development of black or amelanotic tumor nodules. It infrequently metastasizes and the prognosis is good.

Nodular Melanoma

A palpable nodule with rapid growth is present in this variety with the poorest prognosis. A lateral flat component is not seen clinically or microscopically.

The differential diagnosis also includes seborrheic keratosis, senile hemangioma, sclerosing hemangioma, pyogenic granuloma, and pigmented basal cell carcinoma. Eight percent of melanomas in Conley's series were nonpigmented.

Biopsy

An excisional biopsy is performed if the lesion is small. When the location or size makes this impractical, a careful preoperative incisional biopsy is justified. Epstein found

5 there was no evidence to indicate that incomplete removal of malignant melanom followed by definitive surgery, even 1 week later, decreases the probability of survival. A radical resection should obviously be made on only definite histologic proof. Frozen sections also are highly diagnostic.

Prognostic Factors

The two most important prognostic factors are the type of melanoma and depth of invasion. McGovern et al have classified depth of invasion as:

Level 1: tumor confined to the epidermis Level 2: tumor invading the papillary dermis (80-90% 5-year survival) Level 3: tumor filling the papillary dermis (50% 5-year survival) Level 4: tumor invading the reticular dermis (30% 5-year survival) Level 5: tumor invading the subcutaneous tissue (less than 20% 5-year survival).

Tumors less than 2 cm in size have a better prognosis than larger ones. Ulceration is associated with a poorer prognosis. Flat lesions have a better prognosis than pedunculated or polypoid lesions. Women of the premenopausal age have a better prognosis than men.

Metastasis to regional lymph nodes varies greatly according to location of the primary tumor (76% for melanoma of the scalp to 19% for primary superficial melanomas of the cheek). Diffuse hematogenous spread may occur to any organ but has a propensity for the brain, liver, and abdominal viscera. Spontaneous regression rarely occurs.

Staging

Stage I: local disease Stage II: regional metastasis Stage III: distant spread.

TNM classification of Melanoma

T1: smaller than 2 cm in diameter, superifical, no satellite nodules T2: 2-5 cm or with minimal infiltration of dermis regardless of size, no satellite nodules. T3: larger than 5 cm, or with deep infiltration of dermis, or with satellite nodules. N0: no palpable nodes. N1: movable homolateral nodes. N2: movable bilateral or contralateral nodes. N3: fixed nodes. M0: no distant metastasis. M1: distant metastasis or satellite nodule farther than 5 cm from the primary tumor.

Treatment

Conley divides surgical treatment into two basic categories:

6 1. Superficial melanomas of the cheek in females that arise in the lentigo nevus have little capacity for metastasis and should be treated with adequate local excision. Likewise, superficial melanomas of the helix may be treated by wedge excision only because of the low rate of metastasis.

2. Nodular melanomas or melanomas with significant invasion should be treated with wide resection of the primary lesion in continuity with the regional lymphatic drainage. Bilateral neck dissection is not justified and produces no cures for gross metastasis.

Melanoma is radioresistant although an occasional patient may be palliated but rarely cured. Chemotherapeutic agents have produced only minimal short-term improvement. Treatment with a combination of autologous tumor cells, BCG vaccine, and cytarabine was reported by Eldstrom.

Results

The 5-year determinate cure rate in Conley's series of 200 patients with melanoma of the head and neck was 35%. Local excision alone produced a 5-year cure rate of 62%, which rose to 76% with an elective neck dissection if no evidence of metastasis was found in the regional nodes. The cure rate abruptly drops to 25% if occult metastases were found in the lymph nodes. Composite resection when clinically palpable nodes were present reduced the five-year cure rate to 14%. Spontaneous regression, has been reported by Whicker.

Melanoma of the Mucous Membrane

Melanoma of the mucous membrane comprises approximately 10% of the melanomas of the head and neck. The oral cavity is the site of approximately 50% of cases, the nasal and sinus cavities 35%, and the pharynx and larynx 15%. The most common sites are the palate and the inferior alveolus.

Mucosal melanomas are usually not related to junctional nevi and rarely occur in the olfactory area of the superior nasal recess where pigmentation is abundant. Mucosal melanomas are extremely rare in blacks and there is no apparent relationship to local irritation, chronic infection, or allergy.

Nasal or paranasal sinus melanomas presented with epistaxis or nasal obstruction in 88% of patients. The nasal septum and maxillary sinus are the most common sites of origin.

The highest incidence occurs between ages 50 and 70. Grossly, the lesion often appears brownish grey with a smooth, flat lacy pattern that appears deceptively benign. Nasal melanomas present usually as dark fleshy tumors that bleed easily. Conley advises the removal of all pigmented lesions of the mucous membranes in white patients, for diagnostic purposes, as well as prophylaxis. Powell and Cummings cited the differential diagnosis of oral pigmentation:

1. Encdogenous causes: racial, Addison's, Peutz-Jeghers syndrome (intestinal polyposis), polyostotic fibrous dysplasia, jaundice, Cooley's anemia (beta-thalassemia or thalassemia major), sickle cell anemia, thrombocytopenic purpura, hemochromatosis (bronze

7 diabetes), antimalarial therapy, pregnancy, chlorpromazine (Thorazine) therapy, oral contraceptives, neurofibromatosis, hyperpituitarism, hyperthyroidism, infectious mononucleosis, nevi, oral melanosis, melanomas.

2. Exogenous causes: heavy metals (bismuth, lead, mercury, silver, gold, arsenic, copper, chrome, cadmium, zinc, brass), amalgam tattoo, charcoal, intraoral trauma.

3. Endocrine and metabolic causes: nicotinic acid deficiency (pellagra), folic acid deficiency secondary to malabsorption syndrome (sprue), vitamin A or C deficiency, hyperthyroidism, cutaneous inflammatory diseases.

Data by Conley showed metastasis to regional lymph nodes from mucosal melanoma had a lower incidence than melanoma of the skin. Local recurrence after excision varied from 25% in the pharynx to 40% in the nasal cavity and sinuses.

Treatment

1. Local resection: A wide local resection (i.e. maxillectomy) is favored becasue of the realtively low incidence of regional metastasis and the discontinuity in the regional lymphatic system.

2. Electrodessication which gives localized control without extreme ablation is used for superfificial melanomas of the palate.

3. Composite resection of the primary melanoma and the regional lymphatics is applied in continuity when the surgical anatomy permits. For melanomas of the inferior alveolus, lateral pharynx, or floor of the mouth, it is the treatment of choice.

4. Irradiation is almost universally ineffective against melanoma and should never be used as primary treatment. However, some authors use it preoperatively or for palliation, especially in nasal or sinus lesions.

Prognosis

Conley reports a 15% 5-year determinate cure rate; 11% living with melanoma beyond 5 years; and 74% dead within 5 years.

Melanoma of the nasal septum has a better prognosis than melanoma of the turbinates or sinuses.

8 Cysts and Tumors of the Maxilla and Maxilla

Odontogenic Tumors

Ameloblastoma

Ameloblastoma (adamantinoma, adamantine epithelioma, soft odontoma, adamantoblastoma, epithelial odontoma) is a very uncommon neoplasm that arises from odontogenic epithelium or the enamel organ and comprises about 1% of tumors and cysts found in and around the maxilla and mandible. Rarely, ameloblastoma may arise from a dentigerous cyst. Eighty percent of these tumors are found in the mandible, especially in the molar-ramus region. In the maxilla, its predominant sitge is in the cuspid and periantral areas. The average age in reported series is 34-38 years old. The usual symptom is painless swelling with occasional pathologic fracture. The radiographic picture is quite pathognomonic in that it presents multiple radiolucent compartments with a honeycomb arrangement. However, it could present as a unilocular cystic lesion. These are benign tumors though locally invasive, and are radioresistant. Wide local surgical excision is the preferred treatment to prevent recurrence. Inadequate removal may cause wide local spread at a future date. A small number of cases have been reported with pulmonary metastasis. The most frequent extraoral primary site is the pituitary gland.

Grossly, the tumor is seen as a cylindrical or fusiform swelling that expands the bone. Histologically, it has the follicular and the plexiform patterns. The follicular type consists of discrete islands or follicles of epithelial cells in connective tissue stroma. The island of epithelium resembles enamel. In the plexiform type, islands of epithelium form continuous strands.

Adenomatoid Odontogenic Tumor

The other name for this tumor is adenomeloblastoma which is unfortunate because it bears no relationship to ameloblastoma. It usually is located in the anterior teeth in the maxilla. It usually is related to unerupted teeth. The treatment of choice is locally shelling it out. Recurrence is rare.

Ameloblastic Fibroma

This tumor occurs mainly in the premolar-molar region of the mandible. Radiographically, it appears as a unilocular cyst. It usually appears before age 20. The treatment of choice is simple curettage which gives a low recurrence rate. An ameloblasti fibroma with formation of dentin has been referred to as "dentinoma".

Odontomas

Odontogenic tumors may be composed of one or all tissues that make up the normal tooth. They are the most common tumor of the maxilla and mandible. These tumors can arise from cells during any stage of embryogenic development. The most common site in the maxilla and mandible is in the third molar region. It is impossible to make a clinical

9 separation of odontogenic tumors from odontogenic cysts, since they are quite similar and contain the same substances.

X-rays generally show recognizable, though distorted, tooth elements, with or without cystic cavities.

On histologic sectioning (after decalcification), such structures as enamel, dentin, or cementum will be recognized in varying proportions.

These tumors are usually asymptomatic and identified at routine dental x-rays. Conservative removal is the treatment of choice.

Odontogenic Myxoma

Myxomas are tumors composed of young connective tissue similar to the umbilical cord. These are usually central in origin, arising in both the maxilla and the mandible, growing rapidly, and producing marked distortion of the face. The tumor readily expands the bone and loosens the teeth. X-rays show bone expansion, destruction, and trabeculation. Myxomatous lesions in the mandible and maxilla are considered to be benign, whereas those arising in other parts of the body are considered malignant, thus giving rise to the idea that their origin may be different. Though benign, it is locally invasive. Hence, wide total local excision is essential. Radiographically, it is unilocular or multilocular cyst. It is radioresistant.

Odontogenic Fibroma

Unlike odonotgenic myxoma, this is not locally invasive and can be shelled out uneventfully.

Cementoma

This is periapical cemental dysplasia. It is asymptomatic and is a routine dental film finding.

Osteomas

Torus Mandibularis

Torus mandibularis is usually a bilateral osteoma occurring lingual to the lower canine or first premolar. This should be left alone unless symptomatic.

Torus Palatinus

This osteoma occurs in the midline of the palate. It also should be left alone unless symptomatic. Both torus mandibularis and palatinus appear after puberty.

10 Arteriovenous Aneurysm

There are two varieties: (1) congenital and (2) traumatic. It usually presents as swelling, discoloration, pulsation, and a murmur or thrill. Radiographically, a lytic lesion is noted and it is difficult to differentiate it from a benign cyst. Treatment is surgical. Preoperative angiography may be helpful.

Fibro-Osteoma (Ossifying Fibroma)

Fibro-osteomas grow slowly and destroy the normal spongy bone. This fibrous tissue growth shows evidence of osteogenesis. The tumor produces asymmetry of the face - usually one side, either in the maxilla or mandible. In the maxilla, the teeth are spread out, the canine fossa usually obliterated, and the palatal arch asymmetric. In the mandible, there is distortion of the mandibular arch and the bite. The disease appears less often and less extensively in the mandible. In the maxilla, the whole face occasionally is distorted and the eyes displaced upward.

Normal landmarks are obliterated in x-rays. The bone cavity may be completely eroded with no evidence of osteogenesis and the margins of the bore are irregular. In large masses, however, there is usually evidence of both bone destruction and bone formation.

Benign Giant Cell Tumor

This tumor occurs as a solitary lesion. Its origin and classification are disputed by a variety of authors. It is most commonly seen in tghe symphysis and bicuspid tooth areas of the mandible. In the maxilla, the canine fossa area is the most frequent site. The lesion causes expansion and destruction of the bone. Some authors attribute the cause to trauma. Regardless of the cause, a metabolic workup is indicated when such a lesion is found to rule out systemic disease.

X-rays show loss of bone. The margin of the bone loss is irregular in outline and the cavity unequally destroyed, producing a patchy outline on the x-ray. The teeth may be displaced or absorbed, depending on their relation to the cavity.

Endotheliomas

Endotheliomas arise from the lining cells of the blood vessels and most often are seen on the hard or soft palate. These tumors tend to be small, round, and smooth, with an intact mucosa. When very large, the surface may become ulcerated. If lymph node enlargement occurs, it usually is due to infection of the ulcer. Voice change often occurs if the tumor is large.

Odontogenic Cyst

The odontogenic cyst is derived from remnants of the dental lamina or from enamel organs. Symptomatically, it presents as a painless mass. It rarely causes any paresthesia or loosening of a tooth. Malignant degeneration of odontogenic cysts is rarely reported. Odontogenic cysts can be subclassified into:

11 Radicular Cyst (Periapical or Apical Periodontal Cyst)

Radicular cysts are more common in the anterior teeth, and more common in permanent dentition than deciduous dentition. They develop from epithelial rests located in the membrane connecting the tooth root to the bone. They are true epithelial-lined cysts. The treatment is surgical removal of the cyst with preservation of the tooth.

Dentigerous (Follicular) Cyst

Cystic odontoma is a form of dentigerous cyst that arises from the enamel or dental lamina of a developing or developed tooth. They are epithelial-lined sacs around the crown ot an erupting tooth. Classically, they involve the crown of an unerupted tooth with the tooth inside the cyst wall; common sites include the third molar, cuspids, and bicuspids, in that order of frequency. Surgical removal of the cyst is advised with preservation of the tooth.

Eruption Cyst

Eruption cyst is a dentigerous cyst associated with the erupting surface of a tooth, most commonly in third molars. They are above the tooth crown and cause delayed eruption.

Gingival and Palatal Cysts of Newborn

The gingival cysts (Epstein's pearl, Bohn's nodules) are remnants of the dental lamina. The palatal cysts result from epithelial invagination during development.

Lateral Periodontal Cyst

The lateral periodontal cyst is a cyst in bone along the root of a vital tooth.

Primordial Cyst

Primordial cyst form from the enamel organ before any dental tissue develops. They usually occur in the mandibular third molar. Histologically, they have uniform epithelium covered with parakeratin and thick caseous debris.

Odontogenic Keratocysts

These are more common in the mandible and in the third molar areas or ascending ramus. They resemble dentigerous cysts but are distinguished histologically by having a keratinized layer in the epithelial lining. These cysts have a tendency to recur and to become malignant.

Calcifying Odontogenic Cysts

These are epithelial-lined cysts with calcification within the cavity.

12 Nonodontogenic Cysts

Nonodontogenic cysts are derived from epithelial remnants trapped in the embryonic fusion lines during developmental stage.

Globulomaxillary (Premaxilla-Maxillary) Cyst

These are located in the bone. They are alveolar in location, being between the maxillary, lateral incisor, and cuspid teeth. They arise from epithelial invagination between the globular process of the frontonasal bone and the maxillary processes of the palatine bone. The cyst is lined with squamous or respiratory epithelium. It causes facial distortion with elevation of the ala and fullness of the canine fossa. The cyst is best shown on an occlusal intraoral views.

Nasoalveolar (Nasolabial, Klestadt's) Cyst

The nasoalveolar cyst arises from epithelial rests between the globular, lateral nasal, and maxillary processes. Unlike globulomaxillary cyst, it is on the bone with possible erosion of the bone. Ten percent of the patients with nasoalveolar cysts have them bilaterally. It is lined with respiratory epithelium (pseudostratified ciliated columnar) and occurs on the floor of the vestibule anterior to the inferior turbinate. It causes nasal obstruction and elevation of the ala. It can be palpated as a round mass high in the mucobuccal fold above the canine tooth.

Depending on the location, other cysts of the same type have been called nasopalatine, median anterior, maxillary, median posterior palatine, median mandibular, and anterior lingual.

13 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 21: Thyroid and Parathyroid

The Thyroid Gland

Although the thyroid gland is located superficially and is accessible for physical examination, knowledge of its physiologic role was slow to develop. Wharton, who gave the name thyroid to the gland because of its resemblance to an oblong shield, fancied that the gland was present to give a round contour to the neck. Fancier still was the view of Vercellone, who described the gland as a bag of worms, the eggs of which, and occasionally the adult worms, entered the esophagus for digestive purposes. Cower considered the thyroid gland to be part of the lymphatic system. As late as 1884, the thyroid gland was considered a vascular shunt cushioning the brain against sudden increases in blood flow.

In 1827, attempts were made to identify thyroid function by its ablation in animals. Since parathyroid glands were not yet identified, death resulting from tetany was wrongly attributed to the thyroid. Production of tetany from parathyroid removal in 1898 clinched the separate roles of parathyroid and thyroid. Discovery of calcitonin in 1962, established a link between calcium metabolism and the thyroid.

In 1896, the association between iodine and the thyroid was recognized. Kendal, in 1915, extracted L-thyroxine and elucidated its chemical structure in 1026. Thyroxine was considered to be the active hormone until triiodothyronine was discovered in 1926 by Gross and Pitt Rivers.

Graves has been credited as having recognized the association between hyperthyroidism and diffuse enlargement of the gland. DeQuervain, Hashimoto, and Riedel have drawn attention to thyroiditis, an autoimmune disorder.

Development of surgical treatment for thyroid disorders is a fascinating story. Albucasis, a Baghdad surgeon, is credited with the performance of thyroidectomy in 1000 AD. Since then, although several others attempted thyroidectomy, it was only in the latter part of the 19 century that thyroidectomy became an accepted modality of treatment. Theodore Kocher, by his meticulous technique and careful observation, established subtotal thyroidectomy as a safe procedure for treating hyperthyroidism. In the USA, the work of Halsted, the Mayo brothers, Crile, and Lahey, established thyroidectomy as a safe, acceptable procedure for managing thyroid disorders.

Anatomy

The thyroid gland, which in normal adults weighs 15-25 g, is a bilobed structure connected by an isthmus which lies anterior to the second, third, and fourth tracheal cartilages. Anteriorly, the gland is covered by skin, subcutaneous tissue, platysma, deep cervical fascia, strap muscles, and the anterior layer of deep cervical fascia. Posteriorly, the gland is related to the trachea and esophagus; laterally, to the great neurovascular bundle of the neck.

1 The gland is richly supplied with blood by the paired superior and inferior thyroid arteries. The former is a branch of the external carotid artery, and the latter a branch of the thyrocervical trunk of the subclavian artery. In addition, the isthmus in some instances is supplied by the unpaired thyroidea ima, a branch of the aortic arch or the innominate artery. Superior, middle, and inferior thyroid veins drain the blood into the internal jugular and brachiocephalic veins.

Pretracheal and mediastinal nodes drain the isthmus and the medial aspect of the thyroid lobes. The remainder of the gland drains into the deep cervical chain of lymph nodes situated along the internal jugular vein.

The relationship between the gland and the superior and recurrent laryngeal nerves is of surgical importance. The superior laryngeal nerve, arising in the neck as a branch of the vagus nerve, divides into an external motor branch and an internal sensory branch. The external branch innervates the cricothyroid muscle which tenses the vocal cord. The internal branch supplies the laryngeal mucosa after passing through the thyrohyoid membrane. Because of its proximity to the superior thyroid vessels, the external branch is vulnerable to injury during ligation of these vessels.

The recurrent laryngeal nerve arises in the mediastinum as a branch of the vagus nerve. Because of the changes occurring in the embryologic development of the primitive aortic arches, the course of the recurrent laryngeal nerves is different on the two sides. On the right, the fifth and sixth arches disappear and the recurrent laryngeal nerve loops around the fourth arch, which subsequently becomes the subclavian artery. When the origin of the subclavian artery is anomalous, the right recurrent laryngeal nerve will no longer be "recurrent", but arises at a higher level in the neck and passes directly into the larynx. Although a rare occurrence, anyone operating on the thyroid gland should be aware of this anomaly. The left recurrent laryngeal nerve loops around the sixth arch, which subsequently becomes the aortic arch. Both the recurrent laryngeal nerves pass upward in the tracheoesophageal groove to enter the larynx.

Microscopically, the thyroid gland consists of follicles lined by cells, which produce thyroid hormone. In addition to the follicular cells, the gland contains parafollicular or C cells, which produce calcitonin.

Embryology

At the junction of the copula and tuberculum impar, during the fourth week of fetal life, a median diverticulum develops from the pharyngeal endoderm. The diverticulum elongates and descends to occupy a position anterolateral to the trachea and esophagus. While the distal portion of the sinus tract develops into the isthmus and thyroid gland, the portion between the floor of the mouth and the isthmus disappears. Failure of such a disappearance results in the formation of a thyroglossal duct cyst. During its descent, the sinus tract remains in close contact with the ventral aspect of the hyoid bone. Because of this embrylogic relationship, unless the midportion of the hyoid bone is resected while excising thyroglossal duct cyst, elements of the thyroglossal duct are incompletely removed and result in a recurrence.

2 The thyroid gland occupies an ectopic location when the descent of the tract is interrupted or altered. The ectopic locations include the base of the tongue, mediastinum, pericardial sac, trachea, and esophagus. A radioisotope scan is helpful in localizing the gland. Cosmetic deformity and pressure symptoms produced by an ectopic gland may be relieved by administering exogenous thyroid hormone thereby decreasing the size of the gland. Operative removal will be necessary if thyroid suppression fails to relieve the symptoms or when a neoplasm cannot be excluded.

Physiology

Thyroid hormone is necessary for normal development in a maturing animal. In the adult, it plays an important role in maintaining metabolic stability. Both thyroxine (T4) and triiodothyronine (T3) stimulate calorigenesis, potentiate epinephrine, and lower serum cholesterol. At the cellular level, thyroid hormone is believed to mediate its action by its effect on both the mitochondria and the nucleus.

Kinetics of Thyroid Hormone

Iodine metabolism is intimately related to that of thyroid hormone. Normal adults on an average require 80 mg of iodine per day. Seafoods are the natural sources of dietary iodine. In the United States, the dietary intake is as high as 500 mg because of iodization of salt and flour. The ingested iodide is readily absorbed from the gastrointestinal tract and enters the iodide pool, which includes iodide derived from peripheral deiodinization of iodothyronine and nonhormonal iodide, which has leaked from the thyroid gland, in addition to the absorbed iodide. From this iodide pool, iodide exits via two routes: transportation into the thyroid gland and excretion through the kidneys. Iodide transportation into the thyroid cell is an active, energy-dependent process. Since other anions such as perchlorate, pertechnetate, and thiocyanate also are transported through the same mechanism, they act as competitive inhibitors of iodide uptake.

Within the cell, the iodide is oxidized and becomes bound to tyrosyl residues of thyroglobulin. Coupling of two monoiodotyrosyl molecules produces diiodotyrosine which when coupled produce thyroxine (T4). Coupling of a monoiodotyrosine molecule with a diiodotyrosine molecule or removal of a monoiodotyrosine from T4 produces triidotyrosine (T3). Removal of iodine from the inner ring produces what is called reverse T3 (rT3), a triiodothyrosine which is physiologically inert.

The thyroid hormones are stored within the follicles bound to thyroglobulin. Prior to its release into the circulation, the thyroglobulin is taken up by the cell and by proteolytic degradation, T4 and T3 are formed and diffuse into the circulation.

About 80-100 mg of T4 is produced daily, exclusively within the thyroid gland. The half-life of T4 in circulation is 6-7 days and about 10% is degraded daily. However, the rate of degradation is influenced by serum binding as well as tissue factors. The rate of degradation is increased when there is deficiency of thyroid-binding globulin (TBG) and the reverse effect is seen with TBG excess. Regardless of the changes in TBG concentration, the total amount of T4 degraded remains normal, whereas, with hypo- or hyperthyroidism, the total amount degraded decreases or increases, respectively. T4 is metabolized by

3 monodeiodination to form T3 which is several times more potent than T4, or to form rT3, which is physiologically inert. Conversion of T4 to T3 or rT3 is not a random process. T4 is preferentially converted to rT3 during starvation.

Of the 20-30 mg of T3 daily produced, 80% is derived from extrathyroidal deiodinization of T4 and the remainder from the thyroid gland. T3, unlike T4, has a short half-life of 30 hours.

Once released from the gland, T4 and T3 are transported in blood bound to plasma proteins. Under normal conditions, 80% of T4 is bound to TBG, 15% to thyroid binding prealbumin (TBPA), and the remainder to serum albumin. As far as T3 is concerned, 90% of it is bound to TBG, 5% to TBPA, and another 5% to serum albumin. Physiologically active hormone is that portion which is unbound and represents 0.05% of total serum T4 (about 2 ng/dL) and about 0-2 ng/dL of T3. The binding proteins act as reservoirs for storing hormone and help in bufferig the free hormone level.

Secretion of thyroid hormone is regulated by thyroid-stimulating hormone (TSH) of the anterior pituitary. Thyroid-stimulating hormone secretion is sensitive to serum thyroid hormone concentration. A decrease in serum thyroid hormone stimulates TSH secretion and the reverse is true with elevated serum thyroid hormone level. Secretion of TSH is, in turn, influenced by thyrotropin-releasing hormone (TRH) of the hypothalamus.

Thyroid Function Tests

Of the many thyroid function tests available, each one measures some aspect of the kinetics of thyroid hormone and, as such, there is no one ideal thyroid function test. Basically, one need to determine the functional status of the thyroid gland viz. hypo-, eu-, or hyperthyroidism, and if an abnormality is present, the mechanism of the underlying abnormality.

Measurement of the Thyroid Hormone in Serum

Determination of the levels of thyroid hormones is widely used because of its convenience. Serum T4 concentration is measured by radioimmunoassay and the normal is from 5-12 mg/dL. Serum concentration of T4 is affected by two factors: altered secretion by the thyroid gland and serum-binding capacity. An abnormal T4 determination fails to differentiate between the two. For instance, T4 may be misleadingly high in a euthyroid patient because of an increase in the serum concentration of binding proteins. The significance of altered T4 concentration cannot be interpreted without a simultaneous measurement of serum-binding capacity.

T3 Resin Uptake (T3 RU)

This test measures the number of unoccupied protein-binding sites for T4. The test is performed by mixing radio-labelled T3 with the test serum and then adding a resin. Measurement of radioactivity in the added resin measures the amount of T3 bound to the resin. Therefore, when there are many binding sites available for T3, the radioactivity of the added resin will be low and vice versa. Normally, the unoccupied protein-binding sites take

4 up 45-75% of the radiolabelled T3 and the resin takes up 25-55% (see Figure 21-1). It is to be remembered that T3 RU is not a measure of serum T3 level.

Binding sites for T4 may be decreased and T3 RU high due to any of the following conditions: (1) when binding sites are occupied by T4 as in hyperthyroidism; (2) when serum- binding sites are occupied by other ligands such as salicylates and clofibrate; (3) when serum- binding sites are decreased secondary to inhibition of TBG synthesis.

A low T3 RU, which indicates an increase in the available sites for T4 binding, occurs under two conditions: (1) when fewer binding sites are occupied as in hypothyroidism; (2) when TBG formation is increased (Table 21-1).

Concordant changes in T4 and T3 RU values indicate a secretory change whereas discordant values indicate a problem with binding proteins.

Table 21-1. Conditions Which Affect TBG Concentrations

1. Decreased TBG Concentrartion

Androgenic steroids Glucocorticoids Active acromegaly Major systemic illnesses Genetic determination

2. Increased TBG Concentration

Estrogens and hyperestrogenic state Pregnancy Neonatal period Oral contraceptives Biliary cirrhosis Genetic determination Acute intermittent porphyria.

Free Thyroxine (FT4)

Determination of free or unbound T4 measures the physiologically active portion of the hormone and is helpful in eliminating the difficulty in interpreting altered T4 values secondary to changes in binding protein concentration. Free thyroxine can be measured using membrane dialysis and the normal value is 0.4-3 mg/dL. This test is not readily available, takes a prolonged time for completion, and the artifacts induced by defects in dialysis membrane, bacterial overgrowth, and contaminants in radiolabelled T4 have limited its usefulness.

5 Calculated Estimates of Free Thyroxine Level

Because of the cumbersome nature of measuring the FT4 level, a variety of mathematic calculations are employed to derive the same information. The fre T4 index (FTI) is one such. It is the product of total T4 concentration and either T3 RU or the inverse of T3 resin ratio. Although FTI correlates well with the directly measured FT4 in most instances, it may be inaccurate when TBG concentration is markedly changed.

Serum Triiodothyronine Concentration (T3)

Like T4, T3 is measured by radioimmunoassay. The normal value is 70-200 mg/dL. Unlike T4, T3 is depressed in many nonthyroidal diseases. In T3 thyrotoxicosis, T3 is elevated without elevation of T4.

Thyroxine-Binding Globulin (TBG)

The normal value is 1-3 mg/dL. The concentration of TBG can be measured by radioimmunoassay, but the measurement offers little advantage over T3 RU in assaying total serum-binding capacity.

Serum TSH

This is a useful determination to confirm hypothyroidism when T4 and T3 RU are equivocal. In normal subjects, TSH rarely exceeds 10 microIU/mL and is nearly always greater thanb 20 microIU/mL in primary hypothyroid patients. A low T4, T3 RU, and lowered TSH is indicative of hypothyroidism secondary to a pituitary or hypothalamic disorder. Since the presently available methods of assay cannot differentiate between normal and low values, TSH determination is not helpful in confirming hyperthyroidism.

Pituitary-Thyroid Regulation

In normal subjects, administration of TRH is promptly followed by elevation of TSH. Because of TSH suppression in hyperthyroid patients, response to TRH is impaired or absent. Such a response indicates thyroid autonomy. The test is easy to perform. TSH is measured before, 15 and 30 minutes after administration of 400-500 mg of TRH.

Antithyroglobulin and Antithyroid Microsomal Antibodies

In autoimmune thyroiditis, these antibodies are elevated and are helpful in confirming the diagnosis.

Radionuclide Tests

With radioactive iodine and pertechnetate, not only can the uptake of the material from the gland be measured, but also the gland can be scanned to obtain anatomical details delineating areas of altered uptake. Scanning is also of value in detecting ectopic thyroid tissue. Pertechnetate is the preferred agent as it delivers less radiation than iodine.

6 Normal radioiodine uptake is 5-15% at 2-4 hours and 10-30% at the end of 24 hours aftet the administration of the isotope. A low uptake in an otherwise hyperthyroid patient is indicative of factitious hyperthyroidism or thyroiditis.

Sonography

By this noninvasive modality, it is possible to differentiate solid from cystic lesions of the thyroid gland. However, sonography cannot differentiate between benign and malignant lesions.

Biopsy

Tissue for histologic examination can be obtained by cytologic aspiration or using a Vim Silverman needle or one of its modifications. The risk of hemorrhage or of spreading tumor is minimal. It is important to realize that a negative biopsy does not necessarily exclude malignancy.

Diseases of the Thyroid Gland

Hypothyroidism

Hypothyroidism occurs more commonly in females. Cretinism refers to hypothyroidism in infants and, unless recognized early and promptly treated, retardation of physical as well as mental growth occurs. Hypothyroidism may be due to iodine deficiency in the diet or to enzymatic defects, which impair hormonogenesis within the thyroid gland. It also may result from surgical or radiation ablation of the gland, and overzealous treatment of thyrotoxicosis and pituitary or hypothalamic dysfunction.

Hypothyroidism is characterized by slow cerebration, impaired memory, brittle hair, dry thick skin, and in some cases, frank psychosis. The tongue is thick and the voice coarse. Reflexes are prolonged. Bradycardia is often present. Abdominal distention, secondary to constipation and ileus, can occur.

Treatment consists of thyroid hormone replacement.

Hyperthyroidism

The clinical and biochemical syndrome resulting from exposure of tissues to excessive amounts of thyroid hormone consitutes hyperthyroidism. The causes of hyperthyroidism include:

1. Graves' disease. 2. Thyroiditis. 3. Exogenous hyperthyroidism: a. Iatrogenic. b. Factitious. c. Iodine-induced. 4. Uninodular toxic goiter.

7 5. Multinodular toxic goiter. 6. Thyroid carcinoma. 7. TSH excess: a. Pituitary thyrotropin. b. Trophoblastic tumors.

Of the above causes of hyperthyroidism, Graves' disease and multinodular toxic goiter are the most frequent. Hyperthyroidism may be mild or severe, transient or permanent, and the diagnosis obvious or difficult. It is important to identify the cause of hyperthyroidism because the natural history and the treatment varies depending on the etiologic factor.

Since thyroid hormone affects every organ system, hyperthyroidism manifests with multisystem abnormalities. The typical patient is nervous with fine muscular tremors and increased sweating. Heat intolerance, palpitation, increased appetite with weight loss, muscle weakness, and amenorrhea often are present.

Graves' Disease

Components of this syndrome include: (1) hyperthyroidism; (2) diffuse thyroid enlargement; (3) infiltrative ophthalmopathy; (4) infiltrative dermopathy (clubbing of fingers and localized myxedema).

Graves' disease is considered an autoimmune disorder. Thyroid-stimulating autoantibodies belonging to IgG fraction have been detected. The cause of extrathyroidal manifestations of Graves' disease is not known.

Management. Three options are available for managing patients with Graves' disease. These are drug therapy, ablation of the thyroid gland with radioactive iodine, or surgery. The three modalities of treatment are not mutually exclusive and in some instances more than one modality is employed to render the patient euthyroid.

Drug Therapy. Available drugs include: (1) iodine; (2) thionamides (propylthiouracil); (3) monovalent anions (perchlorate); (4) monovalent cations (lithium); and (5) beta-adrenergic blockers.

Iodine, the earliest used antithyroid drug, has only a transient effect in suppressing hormonogenesis. Within 2 weeks of continued iodine administration, the gland "escapes" and the symptoms recur. It is now primarily used in the preoperative preparation to render the gland less vascular and less friable.

Lithium and perchlorate are too toxic for routine use and are infrequently employed.

The most frequently used drugs are propylthiouracil and methimazole. The former has the added advantage of blocking peripheral conversion of T4 to T3. Since the duration of action of these drugs is short, the drug has to be administered three times a day. Adverse reactions to drugs occur in 3-5% of the patients and include drug fever, nausea, diarrhea, and vomiting. Bone marrow suppression and resulting agranulocytosis, the most serious

8 complications, are reversible if detected early and the drug is discontinued. Since methimazol causes a scalp defect in the fetus, the drug is contraindicated during pregnancy.

The incidence of permanent remission following drug therapy is gradually decreasing as compared with earlier reported series. The decline is probably related to increased dietary iodine intake. The most favorable prognostic factors for permanent remission include T3 thyrotoxicosis, a gland enlarged to less than twice the normal size, and serum hormone levels not greater than 50% above the upper limits of normal. Chances for permanent remission are as good following short-term therapy and discontinuation of the drug after attainment of euthyroid status as after continued therapy for a year of more.

Propranolol, a beta blocker, unlike other antithyroid agents, does not suppress hormonogenesis, but blocks the action of the hormone at peripheral sites. Because of its effectiveness, safety, and absence of adverse effects, the drug has in recent years been used with increasing frequency. The dose of the drug is titrated to relieve the symptoms. Beta blockers are best utilized as adjuncts to antithyroid drugs until circulating hormone level is rendered normal.

Treatment with Radioactive Iodine. Low cost, painlessness, absence of risks of an operation and its associated complications have great appeal for the use of radioactive iodine treatment. The disadvantage of this therapy includes a high occurrence (30-70%) of hypothyroidism, an incidence not influenced by the use of frequent smaller doses as opposed to a large single dose administration.

Surgical Treatment. Until the introduction of antithyroid drugs and radioactive iodine for treating hyperthyroidism, the only effective method of treatment was subtotal thyroidectomy. Properly done, the mortality for this procedure is near zero; the incidence of vocal cord paralysis is less than 0.5%. Subtotal thyroidectomy renders the patient euthyroid more expeditiously than either antithyroid drugs or radioactive iodine. The risk of recurrent hyperthyroidism is 3% and of hypothyroidism at the end of 5 years, 5-10%.

For the operation to be safe, the patient preoperatively should be rendered euthyroid either with antithyroid drugs or beta blockers. Overtreatment is preferable to undertreatment in preventing postoperative thyroid storm.

Opinion differs as to the ideal modality of treatment. Treatment selection should be individualized. An important consideration is the age of the patient. Pregnancy is an absolute contraindication for radioactive iodine usage. Since the long-term effects of radioactive iodine on genetic mutations is not known with certainty, radioactive iodine is, in most instances, reserved for patients over the age of 35 years. For those with shortened life expectancy due to concomitant medical disorders, and in those requiring a second neck exploration, radioactive iodine treatment is the preferred method.

Subtotal thyroidectomy is preferred for younger patients of child-bearing age; in patients in whom antithyroid drugs, despite prolonged use, have failre to induce a remission; in those intolerant of antithyroid drugs; in those fearful of radiation effects in any form; and in noncompliers of drug administration instructions.

9 Drug therapy is indicated in preoperative preparation. It also is indicated in young patients since a permanent remission may be induced. For drug therapy to be successful, the patient should be willing to take the medication regularly over a prolonged period and be available for follow-up visits.

Solitary Cold Nodule

The problem with the solitary cold nodule is to determine its nature: benign or malignant. The reported incidence of malignancy in cold nodules varies. A higher incidence is reported in surgical series compared to medical series. The risk factors include: age less than 20 years; male sex; solid nature of the nodule; and cystic lesions larger than 4 cm in diameter. Excepting medullary carcinoma, there are no clinical or laboratory features to differentiate benign from malignant nodules. Sonography, biopsy, aspiration cytology, while helpful in the diagnosis, are not infallible. Therefore, the decision to operate should take into consideration clinical facts.

"Hot" Nodule

Malignant transformation of a hot nodule is rare. Failure of a hot nodule to regress on thyroid suppression, or a chnage from a hot nodule to a cold nodule, needs surgical exploration to exclude malignancy. An autonomous nodule is treated with radioactive iodine or by surgical excision.

Nontoxic Nodular Goiter

The pathogenesis of nontoxic goiter is related to repeated episodes of thyroid hormone deficiency resulting in TSH secretion followed by hyperplasia of the gland. Alternating hyperplasia and involution occurring over a prolonged period causes nodularity. The nontoxic multinodular goiter may either be endemic or sporadic. The former occurs in geographic areas where dietary iodine intake is deficient. The cause of sporadic goiter is not well understood, but is believed to result from ingestion of excess fluoride or calcium which displaces iodine. It also has been observed to be associated with drinking of poluted water contaminated with Escherichia coli. The role of naturally occurring goitrogens in producing the goiter in humans is yet to be elucidated. Faulty utilization of iodine in homonogenesis may be responsible in some instances.

The symptoms depend on the size and location of the goiter. It may be asymptomatic. Mediastinal goiter may produce pressure symptoms on the trachea and esophagus. Large cervical goiters are cosmetically objectionable.

Treatment involves attempts at reducing the size of the gland by TSH suppression with exogenous thyroid hormones. Operative intervention is indicated for cosmetic reasons, to exclude malignancy, and to relieve pressure symptoms. Thyrotoxicosis resulting from hypersecretion of an autosomal nodule is treated with either radioactive iodine or surgical excision.

10 Thyroiditis

There are five categories of inflammatory thyroid conditions: (1) acute suppurative, (2) subacute (granulomatous disease), (3) Hashimoto's disease, (4) Riedel's struma, and (5) nonspecific inflammation. Although in many instances accurate categorization is not possible, its lack does not adversely affect surgical treatment.

Indications for surgical treatment include cosmetic deformity, suspicion of carcinoma, and for relief of pressure symptoms.

Malignant Lesions of the Thyroid Gland

There are two functionally distinct endocrine cells in the thyroid gland: follicular cells and parafollicular or C cells. The former, which secretes thyroid hormone, is the cell of origin for papillary, follicular, and anaplastic carcinoma. The parafollicular cell, a derivative of the neural crest and secretor of thyrocalcitonin, is the cell of origin for medullary carcinoma. Papillary and follicular carcinoma are well differentiated with a relatively good prognosis compared with the poorly differentiated anaplastic carcinoma. The place of medullary carcinoma in its degree of malignancy, falls between the well-differentiated papillary and follicular carcinoma and the poorly differentied anaplastic carcinoma.

Papillary carcinoma, the most frequent of the thyroid cancers, is unencapsulated and multifocal in origin. It spreads via the lymphatics; hematogenous spread is infrequent. Age, sex, and the extent of tumor spread influence the prognosis. A favorable prognosis is noted in patients younger than 40 years of age, in premenopausal women, and when the tumor is within the confines of the gland. A worse prognosis is associated more with local tissue invasion than with lymphatic spread.

Unlike papillary carcinoma, follicular carcinoma is typically solitary and encapsulated. It preferentially metastasizes by the hematogenous route to involve the bones and lung.

The highly malignant anaplastic carcinoma may be composed of either large or small cells. By the time the patient seeks medical attention, the tumor, in most instances, proves nonresectable by the extent of its spread.

Medullary carcinoma is the only thyroid carcinoma which is familial. It occurs, as a component of type II multiple endocrine adenopathy. Therefore, a diagnosis of medullary carcinoma warrants a search for pheochromocytoma and parathyroid adenoma.

Treatment. The modalities available for treating thyroid cancer include: surgery, radioactive iodine, suppression of TSH secretion by exogenous thyroid hormone, external radiation, and chemotherapy.

1. Surgery. Both the extent of thyroid resection and cervical node dissection needed for managing well-differentiated thyroid cancer is controversial. Total thyroidectomy is recommended by some to remove all foci of malignancy within the gland. An added advantage of total thyroidectomy is that it avoids the need for a subsequent second exploration and its associated complications when a remnant left behind by lesser procedures

11 requires subsequent excision to enhance radioactive iodine uptake by metastatic foci. Those opposing total thyroidectomy point out the lack of correlation between histologic malignancy and biologic behavior, as good a result from lesser resection as from total thyroidectomy, and the increased risk of injury to recurrent laryngeal nerves and parathyroid glands associated with total thyroidectomy. In view of the controversy, a reasonable approach is to perform a total lobectomy on the side of the lesion and near total thyroidectomy on the opposite side, and to reserve total thyroidectomy for patients with distant metastasis.

Anaplastic carcinoma, because of its extent of local invasion, is generally unresectable. A biopsy of the lesion to confirm its nature is all that can be done. In the rare instance, when the tumor is resectable, total thyroidectomy is performed. In sporadic medullary carcinoma, unilateral lobectomy is adequate when the tumor is confined to the gland. The familial form requires total thyroidectomy because of the high incidence of bilateral involvement.

The high incidence of microscopic metastatic involvement in normal-looking cervical node lead to the advocacy of prophylactic neck dissection. However, the incidence of subsequent nodal recurrence in patients with normal-looking glands is a low 3%. Therefore, prophylactic neck dissection is not favored in the treatment of well-differentiated cancer. Furthermore, delay in removing the involved nodes does not appear to jeopardize the chance for cure. In anaplastic carcinoma, neck dissection is considered only if the primary lesion is resectable. Node dissection is indicated in medullary carcinoma because of the high incidence of lymphatic metastases. Mediastinal dissection is undertaken in patients having well- differentiated carcinoma with metastasis to central compartment cervical nodes.

2. Radioactive iodine: Total thyroid ablation results in elevation of serum TSH levels. With elevated TSH concentration metastatic foci are stimulated to trap iodine and then radioactive iodine is administered with the hope that the metastatic foci concentrate enough iodine to receive a lethal dose of radiation. The success of the treatment depends on the ability of the metastatic lesions to trap iodine. Metastatic lesions from anaplastic and medullary carcinoma do not trap iodine in sufficient concentration to be therapeutically effective.

3. TSH suppression: The observation that the thyroid is dependent on pituitary TSH for its growth and development lead to the assumption that TSH suppression is beneficial in retarding the growth of well-differentiated cancers. For this purpose, L-thyroxine is administered in doses just short of producing early signs of toxicity.

4. External radiation: In some patients, palliation may be provided in relieving symptoms referable to metastatic, invasive, or incompletely excised lesions using external radiation.

5. Chemotherapy: In general, results with chemotherapeutic agents are disappointing.

Operative Considerations

Mortality from thyroidectomy at present is near zero. Meticulous attention to operative technique, proper preoperative preparation and selection of patient and adequate posoperative care have contributed to the safety of thyroid operations. It is worth remembering that

12 operation is only one aspect in the management of thyroid disorders and for adequate management services of the cardiologist, endocrinologist, anesthesiologist, and pathologist often are needed.

Position of the Patient

Extension of the neck, necessary for adequate exposure, is obtained by placing a pillow or a sandbag beneath the shoulder blades. Bleeding is minimized by decreasing venous engorgement by placing the patient in a semisitting position.The neck is draped exposing the entire anterior aspect of the neck from the chin to the suprasternal notch.

The Incision

In addition to providing adequate exposure, the incision should be cosmetically pleasing. The ideal incision will be at a level where a necklace might rest and cover the scar. The desired cosmetic results will not be obtained by too high or too low an incision, one that is asymmetric, or one that is not along the natural skin crease in the neck.

Elevation of the Flaps

For elevating the flaps, dissection is carried out in the relatively avascular plane between the platysma and deep fascia. The skin, subcutaneous tissue, and platysma muscle are raised as a single layer. The superior flap is raised to the level of the thyroid cartilage and the inferior one to the level of the sternal notch.

Exposure to the Thyroid Gland

Following elevation of the flaps, the deep cervical fascia is incised in the midline between the strap muscles. The midline is identified in the lower part of the neck by the presence of a small amount of fat between the muscles and by the absence of muscle mass to palpation. Lateral retraction of the strap muscles and incision of the anterior layer of the pretracheal fascia exposes the thyroid gland. Wider exposure, when needed, is obtained by transection of the strap muscles. Routine transection of the strap muscles is not necessary. Transection of the muscles near their insertion is recommended to preserve their innervation.

Mobilization of the Gland

Ligation and division of the middle thyroid vein is a prerequisite in mobilizing the gland medially. Unless handled gently, avulsion of the middle thyroid vein from the internal jugular vein can occur resulting in hemorrhage. Gentle median traction on the gland and lateral traction on the carotid sheath expose the vein for safe ligation.

Isolation of the Recurrent Laryngeal Nerve

To avoid injury, the recurrent laryngeal nerve should be exposed before ligation of the inferior thyroid vessels. The posterolateral edge of the gland is exposed by displacing the gland medially and the carotid sheath laterally. The nerve often can be palpated as a cord in the area between the gland and the carotid sheath. Dissection in the areolar tissue, parallel to

13 the course of the nerve, exposes the structure. Once exposed, the nerve is traced to its entrance into the larynx. The nerve also may be identified at its site of entrance into the larynx by its location below and anterior to the cricothyroid articulation.

Ligation of the Inferior Thyroid Vessels

Blind ligation of the artery, because of its variable relation to the recurrent laryngeal nerve, is hazardous. Prior identification of the nerve renders ligation of the artery safe. Although time consuming, individual ligation of the inferior thyroid vessels close to the thyroid gland is preferable to mass ligation for preserving blood supply to the parathyroid gland.

Superior Pole Mobilization

Downward traction on the gland along with elevation of the strap muscles exposes vessels to the superior pole. The vessels should be ligated individually under direct vision, close to the gland, to avoid injury to the superior laryngeal nerve or its branches. Furthermore, individual ligation helps in mobilizing the tongue of the thyroid tissue that ascends lateral to the entry of the vessels into the gland.

Identification of the Parathyroid Glands

Unless invaded by malignancy, every attempt should be made to identify and preserve the parathyroid glands. Their usual location and the characteristic brownish color are helpful in their identification. The superior gland usually is located at the level of the junction of upper and middle thirds of the thyroid, along its posterior border in close proximity to the entrance of the recurrent laryngeal nerve into the larynx. The location of the inferior parathyroid is more variable. Usually it is located close to the thyroid gland where the inferior thyroid vessels enter the gland.

Division of the Isthmus

Loose alveolar tissue between the isthmus and the trachea provides an avascular space for separation of the isthmus from the trachea. During separation, injury to trachea from a sharp instrument should be avoided.

With completion of the above steps, the gland will be ready for resection. The extent of glandular resection depends on the pathologic condition and may involve excision of the nodule, removal of the entire lobe, subtotal thyroidectomy (removal of seven-eights of the gland) or total thyroidectomy (removal of all grossly visible thyroid gland).

Closure of the Wound

Prior to closure, the head is flexed and the adequacy of hemostasis ascertained. If previously transected, strap muscles are approximated with mattress sutures; the deep cervical fascia and platysma are approximated, and the skin edges are carefully brought together with fine sutures or clips. Drainage of the wound is not often necessary, and when a drain is left in it is brought out through one angle of the incision.

14 Thyroidectomy and Neck Dissection

In thin patients, upward extension of the collar incision on both sides provides adequate exposure for neck dissection. In obese patients, and in those with scar from a previous biopsy of the cervical nodes, an incision extending from the mastoid process to the sternal notch and along the clavicle to the trapezius muscle is necessary for adequate exposure. In either event, skin flaps are raised exposing structures from the parotid gland superiorly to the sternum inferiorly, from the trapezius muscle posteriorly to the thyroid gland anteriorly. After detaching the sternomastoid, sternohyoid, and sternothyroid muscles from their attachments to the clavicle and sternum, the internal jugular vein is identified and dissected free from carotid artery and vagus nerve. The vein is transsected low in the neck after ligation. The entire mass of lymphatics, muscle, and the vein are dissected en bloc from the underlying muscle avoiding injury to the brachial plexus, phrenic nerve, spinal accessory nerve, and recurrent laryngeal nerve. The dissection is completed by transsection of the insertion of the strap muscles and sternomastoid muscle and high ligation and division of the internal jugular vein.

Sternal Goiter

Most substernal goiters can be excised by the cervical approach. Furthermore, since the arterial blood supply to the substernal goiter arises in the neck, the cervical approach provides ready access for controlling the arteries. Bleeding, when it occurs, is likely to be venous because of the tourniquet effect of the enlarged gland on the mediastinal vessels. Prompt delivery of the gland into the neck, by relieving the tourniquet effect, allows the veins to collapse and the bleeding to stop. In the majority of instances, the gland can be delivered into the neck by freeing it from the pleura and surrounding mediastinal structures by gentle finger dissection. If difficulty is encountered in delivering a noncancerous goiter into the neck, the contents of the gland are evacuated, after incising the capsule to decrease its size and facilitate its delivery into the neck. A transsternal approach is rarely required.

Transsternal Approach

For removing malignant lymph nodes in the mediastinum and for removing substernal goiters not amenable to the cervical approach, anterosuperior mediastinal exposure is indicated. From the collar incision, a vertical midline incision is made to the level of the fourth costal cartilage. Pectoral muscle attachment to the sternum is freed by subperiosteal elevation. The intercostal muscles in the third space are divided and separated on either side of the sternum. The sternum is transsected at this level and then divided in the midline resulting in an inverted T-shaped incision. Lateral retraction of the sternum exposes the structures in the anterior mediastinum for dissection. The sternum, after completion of the dissection, is approximated with stainless steel wire which is passed through drill holes in the bone.

Postoperative Complications and Their Management

The complications of thyroid surgery can be discussed in relation to the wound, hemorrhage, respiratory difficulty, nerve injury, thyroid storm, recurrent hyperthyroidism, hypothyroidism, and hypoparathyroidism.

15 Wound Complications

These include edema of the flaps, seroma, hematoma, and infection. Edema is often self-limiting and aspiration relieves seroma. Wound infection is usually the result of a concomitant tracheostomy. Adequate drainage and administration of antibiotics help in clearing the infection.

Hemorrhage

Immediate or delayed hemorrhage can occur. The former, a serious complication, should be recognized promptly. Immediate hemorrhage usually occurs in the early postoperative period especially during extubation. The hemorrhage may be either arterial or venous in origin. During coughing, sneezing, vomiting, or straining, insecure venous ligatures can slip secondary to increased venous pressure and profuse bleeding can occur from even small vessels. Profuse hemorrhage may manifest several hours after the operation as a swelling of the neck or stridor. In either instances, it is important to open the wound to the level of the trachea to relieve compression and to insert an endotracheal tube to provide an adequate airway. The wound is explored, preferably under general anesthesia, to secure hemostasis.

Delayed bleeding, which occurs 2-3 days following operation, is due to slow oozing from small vessels. The neck swells and the patient complains of a feeling of tightness. Respiratory difficulty usually is not present. Blood and serum are evacuated by aspiration through a large bore needle or by opening the wound.

Respiratory Obstruction

Laryngeal spasm, edema, hemorrhage, and vocal cord paralysis produce respiratory obstruction. Hypothyroid patients are particularly vulnerable. In them, the already narrowed airway can be readily compromised as the marging of safety between an adequate and inadequate airway is small. Adequate air exchange is provided by either endotracheal intubation or tracheostomy.

Nerve Injury

Stretching, suturing, severing, and crushing can damage both the superior and the recurrent laryngeal nerves or their branches.

Unless complicated by laryngeal edema and the resulting respiratory difficulty, unilateral vocal cord paralysis in the immediate postoperative period may remain unnoticed. Bilateral vocal cord paralysis results in stridor and poses a threat to the patient's life by asphyxiation. Prompt restoration of air exchange is necessary for survival. Paradoxically, the voice remains normal, since the vocal cords occupy a median or paramedian position. Presence of a normal voice could mislead one into discarding the possibility of bilateral nerve injury. Lesser degrees of paralysis result in a monotone quality to the voice; sentences are hurried and interrupted by inspiratory pauses to fill the lung with sufficient air for continuation of speech. Laughter and cough are suppressed to minimize air loss. Suppression of cough, in the immediate postoperative period, predisposes the patient to the development

16 of pulmonary complications. In patients developing respiratory difficulty or stridor several years following thyroidectomy, hypothyroidism and myxedematous infiltration of the vocal cord should be suspected.

Primary repair of the injured nerve has been noted to provide the best result in experimental dogs. Therefore, when nerve injury is diagnosed, the neck is explored to repair the damaged nerve. Three options are to be considered if the nerve function fails to return following primary repair. These include: a valved tracheostomy tube, arytenoidectomy, and nerve-muscle pedicle innervation. While the permanent use of a valved tracheostomy assures a near normal voice and obviates the need for additional operative procedures, the success depends upon the patient, who should be willing to care for a tracheostomy tube and tolerate the associated problems. Arytenoidectomy provides an adequate airway but changes the voice. In the nerve-muscle pedicle innervation operation, the posterior cricoarytenoid muscle is innervated to provide abductor function. Innervation is provided by a branch of the ansa hypoglossi nerve supplying the anterior belly of the omohyoid muscle. Good results with this procedure are reported in patients free from ankylosis of the cricoarytenoid articulation.

Unilateral Recurrent Laryngeal Nerve Paralysis

Although not life threatening, unilateral nerve injury produces varying degrees of incapacity. Since the affected cord remains flaccid, adequate closure of the glottis is not achieved during swallowing, phonation, and coughing. Lack of glottic closure results in ineffective cough, rendering eradication of pulmonary complications difficult. The glottic closure can be improved by rendering the paralyzed cord firm by injecting it with glycerin, Gelfoam paste, or Polytef. The effect of glycerin injection lasts for 2-3 days and that of Gelfoam paste 6-10 weeks. The effect of Polytef injection is permanent.

Superior Laryngeal Nerve Injury

The internal branch is rarely injured. The external branch may be injured on one or both sides, along with the recurrent laryngeal nerve and in various combinations. In unilateral nerve injury, the damage is often overlooked and at rest, the larynx appears normal but becomes asymmetric during phonation. Bilateral injury may be missed unless tensing of the vocal cords is looked for during phonation. Excess leakage of air during phonation produces a low-pitched, poorly controlled voice.

Isolated superior laryngeal nerve paralysis need not be treated since it is often adequately compensated. In patients with problems of phonation, Teflon injection has been found helpful.

Thyroid Storm

Once a fairly common complication, thyroid storm is rarely seen since the introduction of antithyroid drugs in the management of thyrotoxic patients. "Thyroid storm" refers to a life-threatening exacerbation of all the metabolic features of thyrotoxicosis. Fever, which is not a feature of uncomplicated thyrotoxicosis, is pathognomonic of thyroid storm. Until proved to the contrary, thyroid storm should be suspected in thyrotoxic patients with a temperature higher than 100°F.

17 The prognosis depends on how soon the treatment is instituted; the sooner thre treatment, the better the prognosis. Therefore, treatment should be begun at the earliest suggestion without waiting for the overt signs to develop.

Soidium iodide, the first drug used effectively in the management of thyroid storm, is given in combination with other agents. It is no longer relied upon as the sole agent for the management of this complication. Propylthyouracil is administered in large doses. By its administration, synthesis of thyroid hormone as well as peripheral conversion of thyroxine (T4) to the more potent triiodothyroxine (T3) are blocked. The peripheral effects of thyroid hormone are blocked by administering sympatholytic agents such as propranolol. A beta- adrenergic blocking agent, propranolol, following oral administration, exerts its effect in 4-6 hours. Where immediate response is desired, the drug can be given intravenously with closxe cardiac monitoring. Although the mechanism of action is not yet clear, cortisone has been found to be highly effective.

In addition to the above specific measures, supportive measures are instituted including ice packs or cooling blanket to decrease body temperature; administration of fluids and electrolytes, sedatives, oxygen, and multivitamins. Salicylates, because of their ability to facilitate conversion of T4 to the more potent T3, are contraindicated.

Hypothyroidism and Hyperthyroidism

Exogenous thyroid hormone is administered to treat hypothyroidism resulting from excision of excessive amount of the gland. Insufficient excision of the gland results in persistent hyperthyroidism. To avoid the risk of reexploration, radioactive iodine is the preferred method of treating recurrent or persistent hyperthyroidism.

Hypoparathyroidism

Inadvertent removal of the parathyroid glands or damage to their blood supply leads to hypocalcemia, which may be latent, transient, or permanent. Latent hypoparathyroidism, which may persist for years, may not become evident until calcium-lowering drugs, such as furosemide and steroids, are administered or metabolic demand for calcium is increased as in pregnancy.

The symptoms of hypoparathyroidism are due to decreased ionized serum calcium and resulting neuromuscular excitability. The level of calcium, as well as the rate of fall in serum calcium, determine whether a patient does or does not develop symptoms. The symproms include paresthesia of the limbs and perioral tissues. Laryngeal stridor, rarely convulsions, can occur with severe hypocalcemia. Facial muscle irritability and carpopedal spasms may occur spontaneously, or be demonstrated by tapping the branches of the facial nerve (Chvostek's sign) and by occlusion of the blood supply to the upper extremity with a tourniquet (Trousseau's sign). Weakness, fatigue, numbness, tingling, emotional instability, anxiety, depression, and delusions are features of chronic hypocalcemia. The convulsions of hypocalcemia should be differentiated from epilepsy. Other sequelae of chronic hypocalcemia include lenticular opacity and dystrophic changes in the skin and its appendages.

18 Calcium gluconate, when administered intravenously, promptly restores the serum calcium level and alleviates symptoms of hypocalcemia. The injections are repeated as often as needed to maintain the serum calcium level at 8 mg/dL. For correction of persistent hypocalcemia, oral vitamin D, or its more potent analogues, and calcium are administered. The chance of the occurrence of tetany is decreased by lowering the serum phosphorus level by the exclusion of foods rich in phosphorus such as chocolate and dairy products. Aluminum hydroxide gel, which binds dietary phosphorus and thereby prevents its absorption through the gut, is helpful in further lowering serum phosphorus. The calcium level in serum should be closely monitored for a prolonged period to avoid hypercalcemia and its sequelae - hypercalciuria and renal stone formation - resulting from vitamin D intoxication.

The Parathyroid Glands

Hyperparathyroidism, the most frequent parathyroid disorder requiring surgical treatment, results from both hyperplasia and neoplasia of the thyroid glands. The former may be either sporadic or familial, or may occur as a component of the syndrome of multipe endocrine adenomatosis. Adenoma and carcinoma constitute the neoplastic lesions. The incidence of hyperplasia and adenoma varies widely from series to series because of the difficulty in their histologic differentiation. The reported incidence of carcinoma ranges from 0.6-4%.

Hyperparathyroidism may be primary or secondary. In primary hyperparathyroidism, idiopathic disruption of the normal feedback mechanism regulating parathormone secretion results in inappropriately high parathormone secretion for the serum calcium level. On the contrary, in secondary hyperparathyroidism, an increased amount of parathormone is secreted to compensate for the decreased serum calcium level which occurs in chronic renal disease, hypovitaminosis D, vitamin D-dependent rickets, calcium malabsorption, hyperphosphatemia, and renal tubular acidosis. Hypersecretion of the parathormone usually subsides once the causative factor has been eliminated. However, after being stimulated for a long period, the glands may fail to revert to normal function and continue to secrete parathormone inappropriate to the calcium level. This situation is termed tertiary hyperparathyroidism. Pseudohyperparathyroidism refers to the hyperparathyroid state resulting from the secretion of parathormone or parathormonelike substance by a variety of nonparathyroid tumors.

In recent years, the most frequent presentation of hyperparathyroidism has been the finding of an elevated serum calcium level on a routine examination using the multiphasic channel analysis. Therefore, in the differential diagnosis, other conditions causing hypercalcemia should be considered.

These include:

Sarcoidosis

Hypercalcemia presumably is due to increased absorption of calcium from the gastrointestinal tract secondary to exaggerated sensitivity to vitamin D. The diagnosis often is made by findings on chest x-ray, lymph node biopsy, and a normal serum parathormone level.

19 Multiple Myeloma

An elevated serum calcium level is present in about 40% of the patients. X-ray examination of bones, bone marrow examination, and serum electrophoresis aid in establishing the diagnosis.

Vitamin D Intoxication

Prolonged excessive ingestion of vitamin D results in an elevated serum calcium from increased bone resorption and enhanced gastrointestinal absorption. A careful history provides the diagnostic clue.

Milk-Alkali Syndrome

This is a complication resulting from ingestion of calcium containing absorbable antacids and milk for the treatment of peptic ulcer. This condition has become less prevalent since nonabsorbable antacids are used more frequently than in the past. The history will provide a diagnostic clue and, when cessation of ingesting milk and absorbable antacids brings down the serum calcium level, the diagnosis is confirmed.

Immobilization

Prolonged immobilization results in loss of calcium from bone and when the rate of bone resorption exceeds the ability of the kidneys to excrete calcium, hypercalcemia results.

Thyrotoxicosis

Marked hypercalcemia is rare and probably is due to increased bone resorption. Thyroid function studies confirm the diagnosis.

Adrenal Insufficiency

The cause of hypercalcemia is not known.

The diagnosis of primary hyperparathyroidism is established by excluding other causes of hypercalcemia, including malignancy, and by finding an elevated serum calcium level in association with an elevated parathormone level. Increased urinary cyclic adenosine monophosphate confirms the presence of parathormone effect, but not necessarily primary hyperparathyroidism.

The presenting features of primary hyperparathyroidism are related to hypercalcemia and the effect of parathormone on bones. Symptoms resulting from hypercalcemia are by no means unique to hyperparathyroidism and include renal stones, nephrocalcinosis, depression, easy fatigability, peptic ulcer, pancreatitis, constipation, and mental changes. Increased calcium in the urine results in polyuria and polydipsia. Band keratitis and calcium deposits in palpebral tissue may be present. Bone pain, bone cysts, and pathologic fractures result from bone resporption.

20 Surgical Management

In recent years, because of the ready availability of multiphasic serum analysis, primary hyperparathyroidism is diagnosed with increasing frequency in asymptomatic patiens. Such early diagnosis poses questions: what is the natural course of the disease in this group of patients, and should they be operated upon? There are no definite answers. A prospective study of such patients at the Mayo Clinic revealed that 20% required operation within 5 years because of the development of symptoms and another 20% were lost to follow-up. Based on their experience, the Mayo clinic group recommends surgical treatment in asymptomatic patients, unless the risk of operation is excesssive because of the presence of concomitant medical disorders.

The aim of surgical treatment is to remove all abnormal parathyroid tissue and to conserve enough of the tissue to maintain euparathyroid status. While the aim is defined, execution poses problems because of the variable number and location of the glands, their small size, and the lack of accurate histologic criteria to differentiate normal from abnormal glands and hyperplasia from neoplasia.

Number and Position of the Glands

Normally, four glands are present. A decrease or increase in their numbers can result from fusion and fission of the developing anlage. Two glands were present in 0.2%, three glands in 6.1%, four glands in 87%, five glands in 6%, and six glands in 0.5% of autopsy studies conducted by Gilmour.

The superior parathyroid glands develop from the fourth branchial pouches and the inferior parathyroids from the third. Because of their greater descent, the position of the inferior parathyroids is more variable. The gland may be located in close proximity to the thymus, pericardium, or heart. A superior gland, when it fails to descend to its normal position, will be located high in the neck near the hyoid bone. In addition to their variable locations related to embryologic development, an enlarged gland may shift its position because of its weight and the influence of negative intrathoracic pressure. An enlarged parathyroid gland may be located anywhere betweem the hyoid bone and the mediastinum. It may be present within the thyroid gland, behind the esophagus, in the anterior or posterior mediastinum, between the trachea and esophagus, or within the carotid sheath.

Gross and Microscopic Features

The average gland, which weighs approximately 35 mg, may be oval, round, irregular, or flattened, and has a characteristic tan brown color.

In addition to parathyroid tissue, the gland contains adipose tissue, which increases with age. The differentiation between a normal and an abnormal gland and between hyperplasia and neoplasia is not always easy on microscopic examination. The diagnosis of adenoma is favored in the presence of uniglandular enlargement and that of hyperplasia with multiglandular enlargement. The diagnosis is further complicated by the presence of microscopic hyperplasia in normal-sized glands and, conversely, by the abscence of abnormal microscopic features in enlarged glands. Wang and Rieder have described an intraoperative

21 density test for differentiating a normal from an abnormal gland. They have observed that abnormal parathyroid tissue sinks in mannitol solution within the density range of 1.049- 1.069, whereas normal parathyroid tissue floats. The diagnosis of adenoma is made when tissue from one gland sinks, while tissue from another floats, indicating uniglandular involvement. When tissue from both glands sink the diagnosis of hyperplasia is made, on the assumption that glandular involvement is generalized.

Localization Studies

Preoperative knowledge of the location of the glands in any patient undergoing neck exploration is of obvious advantage to the surgeon. Unfortunately, a safe, reliable, noninvasive, and cost-effective test is not available for localizing the glands.

A clue to the location of an abnormal gland may be obtained by a mass seen in the mediastinum in a chest x-ray or by extrinsic compression of the barium column in an esophagogram. Scanning of the gland, using radioactive selenomethionine, has not proved helpful. Sonography and computed tomography have had limited trials and need to be further evaluated. Catheterization of neck veins, and parathormone assay on blood drawn at different sites, is helpful in localizing the abnormal gland. Selective angiography can aid in locating the abnormal gland, but is less dependable than venous catheterization and parathormone assay of venous blood. Both these tests - selective angiography and venous catheterization - are not without complications. Hemiplegia and paraplegia have been reported to occur following angiography. In addition, these tests are not uniformly successful, they require trained personnel for their performance, and are not cost effective. These studies, therefore, are reserved for patients requiring reexploration following a cervical exploration which was unsuccessful in locating the abnormal gland.

Intraoperative location of the gland has been attempted by intravenous injection of methylene blue. The recommended dose is 5 mg/kg of body weight diluted in 250-500 mL of a crystalloid solution. The concomitant staining of thyroid tissue by the dye has hindered its usefulness.

Operative Strategy

Unless the neck exploration is carried out in a systematic, unhurried manner with meticulous attention to avoid staining of tissues with blood, identification of the glands become difficult, if not impossible.

Opinions vary as to the extent of neck exploration and glandular resection that has to be performed. Wang and Rieder recommend removal of an enlarged gland and termination of the operation if another ipsilateral gland is normal. On the other extreme, Paloyan et al have recommended near-total parathyroidectomy. Evidence indicates that the more radical approach of Paloyan, while increasing the incidence of hypoparathyroidism, does not increase the cure rate.

A reasonable approach is to explore both sides of the neck and to visually identify all four parathyroid glands. Biopsy of the gland is resorted to if doubt exists as to its nature. While taking the biopsy, care should be taken to avoid injuring the blood supply of the gland.

22 In instances of uniglandular enlargement excision of the involved gland, and in instances of multiglandular enlargement excision of three and one-half glands (subtotal parathyroidectomy), have given satisfactory results in controlling hypercalcemia. In patients with familial hyperparathyroidism and multiple endocrine adenomatosis, subtotal parathyroidectomy is the procedure of choice even though only one gland is enlarged, because of the high incidence of recurrence with resection of a lesser extent.

While performing subtotal parathyroidectomy, it is important to transect the gland that is to be retained before removal of the other glands. This precaution provides opportunity to leave a vascularized remnant of another gland if the earlier transected gland becomes devascularized. Unless this precaution is taken, the patient may become permanently hypoparathyroid. In the presence of a hard greyish mass, carcinoma should be suspected, and the gland with its surrounding structures is widely excised to avoid capsular disruption and spillage of cells. Recurrence can occur with spillage of the malignant cells.

Failure of visualization of one or more glands may pose problems. If an abnormal gland is found and the other glands visualized are normal, exploration is terminated after a reasonable search, since the chance of cure is high. Under these circumstances, extensive search is ill-advised because of the risk of devascularizing normal parathyroid tissue and injuring the recurrent laryngeal nerve. If all the four visualized glands are normal, a search should be made for a supernumerary gland. When only three normal glands are visualized, the fourth missing gland should be diligently searched out. The missing gland may be located high in the neck at the level of the hyoid bone, in the mediastinum, inside the thyroid gland, in the carotid sheath, or in the retroesophageal or retrotracheal space.

The relationship of the recurrent laryngeal nerve to the parathyroid gland is of help in choosing the areas to be explored for the missing gland. The superior gland is likely to be in the posterior mediastinum posterior to the nerve and the inferior gland in the anterior mediastinum anterior to the nerve. When the inferior gland is missing, the thymus is removed through the cervical approach, and if still not found within the thymus, an ipsilateral hemithyroidectomy is performed to remove a possible intrathyroid gland. If still not found, the retrotracheal, retroesophageal areas, and the carotid sheaths are explored. Every attempt should be made to locate the missing gland during the first exploration since subsequent exploration is technically more difficult and hazardous.

When the missing gland is not detected following a careful thorough neck exploration, the operation is terminated. Some patients are cured presumably by destruction of the blood supply to the abnormal gland during neck exploration. Those with persistent hypercalcemia are restudied to confirm the diagnosis and to localize the missing gland. Mediastinal exploration will be required in about 55% of the cases. Interestingly, a majority of the missing glands are found in the neck at reexploration.

Secondary Hyperparathyroidism

The number of patients with secondary hyperparathyroidism has increased as a result of the reduction in mortality from chronic renal failure by effective dialysis, improved medical management, and increasing success with renal transplantation.

23 Maintenance of normal serum calcium and phosphorus levels is aimed for to prevent parathyroid stimulation and development of secondary hyperparathyroidism. Skeletal and extraskeletal complications are minimized by maintaining normal levels of serum calcium and phosphorus. A decrease in the dietary intake of phosphorus is essential to prevent hyperphosphatemia. Further reduction in the serum phosphorus level is achieved by preventing absorption of phosphorus in the gut by binding dietary phosphorus with aluminium hydroxide or carbonate. Administration of calcium supplements, vitamin D, or its more potent analogues, help in elevating the serum calcium level. Despite these measures, renal osteodystrophy may progress in some patients necessitating parathyroidectomy to treat bone pain, pathologic fractures, intractable pruritus, and extraskeletal calcification. The procedure of choice in such patients is subtotal parathyroidectomy or total parathyroidectomy with autotransplantation of parathyroid tissue into a forearm muscle.

Total Parathyroidectomy, Heterotopic Autoimplantation, and Cryopreservation

Parathyroid tissue, both in experimental and clinical studies, has been successfully implanted into muscle. In those instances where the recurrence is high following subtotal parathyroidectomy, to avoid the risks of cervical reexploration, total parathyroidectomy and autoimplantation into a forearm muscle are resorted to. Following autoimplantation into a forearm muscle, if hyperparathyroidism recurs, the problem is easily dealt with by excising portions of the implanted parathyroid tissue under local anesthesia. Indications for this procedure include renal osteodystrophy in patients who are not candidates for renal transplantation, multiple endocrine adenomatosis, and familial parathyroid hyperplasia. There is risk of rendering a patient hypoparathyroid, who had total parathyroidectomy and autoimplantation, if the implant fails to survive. Preservation of the excised parathyroid tissue provides material for subsequent reimplantation, if the need arises. It has been demonstrated that parathyroid tissue frozen in dimethyl sulfoxide and autologous serum remains viable as long as 9 months.

Hypoparathyroidism

Primary hypoparathyroidism is a rare diseae. Hypoparathyroidism is, in almost all instances, secondary to thyroidectomy and is discussed under complications of thyroidectomy.

24 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 22: Facial, Plastic, Head and Neck Reconstructive Surgery

I. Basic Information on Flaps and Grafts

Skin Grafts: (Fig. 22-1)

1. Thiersch graft = 0.008 in - 0.010 in. 2. Split-thickness graft = 0.010 in - 0.018 in 3. Dermal graft = dermis only 4. Full-thickness graft = epidermis + dermis.

Thiersch and Split Thickness Grafts

Advantages

1. High percentge of take. 2. Donor site heals without a graft. 3. Gives excellent immediate cover.

Disadvantages

1. No tensile strength. 2. Poor color match. 3. Contraction on healing. 4. Lacks bulk.

Full-Thickness Graft

Advantages

1. Less contracture. 2. Better color. 3. Greater bulk.

Disadvantages

1. Small areas. 2. Poorer take.

Dermal Grafts

Advantages

1. Strong - will take in irradiated tissue. 2. High resistance to infections.

1 Uses

1. For carotid artery cover following neck dissection in irradiated patients. 2. For pharyngeal suture line cover in irradiated patients.

Physiology of Graft Nutrition

0-12 hours Plasma circulation, nutrition to graft by imbibition of exudate from host bed. 12-24 hours Inosculation - direct connection of graft and blood vessels. 24-48 hours Host vessels grow into graft. 48 hours on Peripheral cellular union of graft and host with epithelialization.

Plasmatic circulation works as follows: The hydrostatic pressure at the capillary end of the skin's capillary-venule glomerulus drives crystalloids through the interendothelial cement substance into the tissues where they become tissue fluid. This tissue fluid flows between the fibers of collagen and elastin, embedded in mucopolysaccharides of the ground substance. To recirculate or to return to the donor circulation, the tissue fluid can do so by lymphatic circulation or by the blood circulatory system directly. An open wound does not havee a plasmatic circulation, and hence the tissue fluid escapes through the portal of the wound and is not recirculated. A wound covered with a skin graft permits restoration of vascular and tissue-fluid balance, returning plasmatic and hemic circulation to normal.

Hemic circulation of the graft depends on capillary buds that grow from the donor towards the graft's circumference by seemingly purposeful orientation. Blood flow can be detected microscopically in new capillary buds by the fourth day.

Once the transplant has a vascular purchase on the host bed, peripheral cellular union of graft and host is accomplished by epithelization. The rate of epithelization is about 0.5 mm/day.

Vascularization and graft take depend on:

1. Healthy host bed with adequate blood supply. 2. Adequate fixation and immobilization. 3. No infection. 4. Graft over bone or cartilage requires intact periosteum or perichondrium.

Causes of failure of graft take:

1. Graft: a. Tension. b. Inadequate immobilization. c. Inaccurate approximation of graft to host bed and the margins.

2 2. Host bed: a. Infection. b. Poor hemostasis (hematoma seroma). c. Fibrosis of bed. d. Irradiation of host bed. e. Lack of perichondrium or periosteum over cartilage and the bone.

Major Flaps in Head and Neck Reconstructive Surgery (Pedicle Flaps)

A. Classification:

1. Forehead. 2. Medially-based chest flap. 3. Laterally-based chest flap. 4. Nape of neck.

B. Definition: Pedicle flp (vascular attachment to the body at all times by transferred tissue).

C. Basic concepts:

1. Based on arterial supply. 2. A flap is an island. The width of the base of the flap is unimportant beyond the necessity to contain a vascular pedicle. 3. Tubing of flap is useful if only the distal portion is used in the transfer (prevents infection and granulation). 4. Delay of flaps: a. Decision based on need. b. Will increase chances of survival. c. Effects dermal and subdermal vessel hypertrophy and hyperplasia with a 7-14 day delay. d. Allows greater length of flap for use. 5. Transfer of blood supply from graft site distal, useful end of flap - approximately 14 days. 6. Flaps die of congestion, rarely from anemia. 7. The patient's blood pressure, hemoglobin, and hematocrit are vital for flap survival. 8. A clean, well-vascularized bed required for transfer. 9. No tension at suture line. 10. No twisting of pedicle or pressure on pedicle allowed or impairment of flap circulation will occur.

Advantages and Disadvantages of the Flap

1. Capable of carrying tissues other than skin. 2. Carries its own blood supply, therefore, more likely to "take". 3. Less tendency to discolor, more resistant, more elastic, more movable, and less likely to contract. Although a 25% leeway should be kept in mind in the planning of a pedicle flap.

3 4. More adaptable to weight bearing. 5. Capable of bridging a defect. 6. Can be used on a host bed of questionable nutrition. 7. No pressure dressing necessary. 8. One disadvantage is that it usually needs many stages.

Forehead Flap

Arterial base: Superficial temporal artery and postauricular artery. Note: Flap can be based on scalp vessels should the external carotid be tied in a previous major procedur. Delay: Rarely necessary but can be achieved by isolation and ligation of the supratrochlear and supraorbital vessels on both sides. Uses: Buccal cavity, oropharynx, hypopharyngeal reconstruction, chin and neck skin reconstruction. Methods of entry: 1. Beneath or above the zygoma. 2. Through a cheek incision to the buccal cavity. Disadvantage: Disfiguring in females (nipple in the neck). Special uses: A bipedicle bucket handle forehead flap for chin reconstruction. Donor site: Closed by immediate or delayed skin grafting.

Specific Forehead Flaps

1. Forehead island flap: The flap is based on the supraorbital or supratrochlear artery. It is a full-thickness skin flap with a subcutaneous pedicle carrying the artery. It is transferred subcutaneously and is useed as a full thickness skin graft over the nasal bridge. 2. Indian forehead flap: It is based on the superficial temporal artery. It is used for nasal reconstruction. The disadvantage is a minor cosmetic defect. Closure of the donor site is with a split-thickness skin graft. 3. Median forehead flap: Based on supratrochlear-supraorbital artery, its donor sitee is closed primarily.

Medially-Based Chest Flap

Arterial base: Includes four perforated arteries of the internal mammary artery. Delay: Advisable. Allows greater length and greater reliability. Staged delay: Increases length possibilities and reliability. Uses: Buccal cavity, orohypopharyngeal, and cervical esophageal reconstruction following major head and neck reconstruction. Reliable, particularly following delay. Donor site: Closed with split-thickness skin graft, immediate or delayed.

Laterally-Based Chest Flap

Arterial base: Acromiothoracic artery. Delay: Preferable but not necessary. Will increase both length and reliability. Disadvantages: Disfiguring in females (nipple in the neck). Uses: Buccal-oral cavity, hypopharyngeal, and laryngopharyngeal recostruction. Donor site: Covered by split-thickness skin graft, immediate or delayed.

4 Nape of Neck

Arterial base: Occipital artery. Delay: Essential. Uses: Neck skin replacement, cervical esophageal reconstruction, oral cavity and hypopharyngeal reconstruction. Disadvantges: One of the least reliable of major head and neck flaps. Donor site: Covered with split-thickness skin graft, delayed or immediate.

The Usee of Flaps and Pharyngostomes in Irradiated Patients

In using flaps for head and neck reconstructive surgery, careful planning is essential. Such planning allows preparation for possible complications. In initial surgery on irradiated patients, discretion is always the better part of valor. It often is desirabl to create a pharyngostome to be sure of adequate carotid coverage and healing before planned reconstruction at a later date. Prepared delayed chest flaps with greater length and reliability prior to definitive surgery decreases the risks of failure of the flap on reconstruction.

Transposed, Advancement, and Interposed Flaps

Definition: Use of local viable tissue to close a defect, with simultaneous staggering of the inevitable scar line.

A. Types: 1. Z-plasty. 2. Simple advancement. 3. Bilobe advancement. 4. V-Y closure. B. Advantages: 1. Viable graft tissue with excellent blood supply. 2. Tissue close to the defect, subsequently excellent color and texture match. 3. Good scar camouflage. 4. Adequate thickness, hence less contracture. 5. Necrosis rare with correct planning. C. Disadvantages: Limited by local available tissue. D. Uses: 1. To correct contracted linear scar. 2. To reposition malposed tissue. 3. To close facial cutaneous defects.

Z-Plasty

A. Definition: Classically, the Z-plasty is based on a Z figure. The central limb and arms are of equal length. The arms are at opposite nds of the central limb and parallel. Therefore, the two angles so formed are equal. B. Principle: 1. The greater the angle the greater the amount of gain. Inevitably, the greater the angle the more difficult the flap transposition.

5 2. In general, the 60° Z-plasty is the most widly used, giving good lengthening and a reasonable margin of safety for flap survival. 3. When facd with a long scar revision, multiple Z-plasties are preferable to large Z- plasties. 4.A60° angle Z-plasty gives a 73% increase in scar length. C. Uses: 1. To prevnt scar contracture. 2. To change plane of scar. 3. To reposition poorly placed tissue. 4. To remove webbing. 5. To close cutaneous defects. 6. To remove "dog ears". 7. To augment tissue. 8. To correct defects at the commissure of the mouth, eye, etc. 9. To enlarge a constricting tracheostome.

Composite Grafts

A. Definition: Graft which contains two layers of tissue, i.e. skin and cartilage. B. Uses: Ear, nose, eyelid, and trachea. C. Principles: 1. Handle with care. 2. Always use sharp instruments when taking a graft. 3. Use no electrocautery to graft or vessel ligation. 4. Never allow the periphery of the graft to be at a greater distance than 1.5 cm from the center. The length is irrelevant. 5. Fine sutures (6-0) when suturing in place. D. Bed: 1. To have well-nourished recipient site. 2. To have no infection.

Methods of Increasing Graft Survival

1. Cooling of graft to decrease metabolic requirements. This appears to allow increase in size of periphery-to-center of up to 2 cm. Disadvantages: Edema of graft appears to last for a longer period. 2. Treatment of donor site with histamine dichloride. 3. Galvanic current stimulation to donor site one day before surgery.

Crane Principle

1. Use of pedicle flap of skin and subcutaneous tissue. 2. The bulk of the flap is returned to the donor site leaving the subcutaneous tissue at the graft site. 3. Skin graft is then used to cover the grafted area. 4. Applicable to head and neck surgery for large areas of exposed skull after periosteum has been removed in the treatment of scalp cancers.

6 II. Myocutaneous Flap

In recent years the myocutaneous flap has become the major method of reconstruction employed by head and neck surgeons. Cadaver dissections and subsequent operative experience have permitted surgeons to better understand and apply the fundamental principles of flap design, muscular and cutaneous circulation, and appropriate indications and limitations of these flaps. As experience has increased and more series published, it has become clear that optimal results are obtained only when strict adherence to fundamental surgical tenets is observed.

Definition

Myocutaneous Flap: A myocutaneous flap is a flap that incorporates as a single unitt muscle and envloping fascia, subcutanenous elements, skin, and vascular suppor. They are axial in design, incorporating a major blood vessel which runs along the entire undersurface and provides perforators to the muscle and skin along its course. A random flap extending beyond the myocutaneous flap can be incorporated providing the subcutaneous tissue and fascia are carried with the overlying skin (Fig. 32-2). Currently, four flaps are used in head and neck reconstruction. These include:

1. Sternocleidomastoid flap (SCM). 2. Trapezius flap (TPZ). 3. Pectoralis major (PM). 4. Latissimus dorsi (LD).

General Considerations Regarding Myocutaneous Flaps

1. The skin overlying the muscle bulk is supplied by both cutaneous arteries and musculocutaneous arteries. 2. Myocutaneous flaps may be used without delay. 3. Myocutaneous flaps add bulk when extirpative surgery has left a large (and often deep) defect. 4. Myocutaneous flaps may be used in a field previously treated with radiation (see 10). 5. The myocutaneous flap may become a "functional flap" as it is employed in esophageal reconstruction. 6. Myocutaneous flaps may be used to transfer underlying bone which can be used for facial reconstruction. 7. Reported epithelial loss in skin paddles has been associated with minimal morbidity; fistulization is uncommon. 8. Myocutaneous flaps can be performed with relative ease by the skilled surgeon. 9. Myocutaneous flaps are readily available and reliable. 10. These flaps may be radiated postoperatively.

7 Sternocleidomastoid Myocutaneous Flaps

Anatomy

This muscle arises from two heads: a round tendonous head that takes off from the manubrium on its anterosuperior surface and a muscular head from the medial upper third of the clavicle. The anterior cervical triangle fascia splits to envelop the muscle. This is of major importance in conservation surgery. The two heads unite to form a common body which passes superiorly and posteriorly to insert on the mastoid process. Small slips of muscle attach to the superior nuchal line of the occipital bone.

Arterial Supply

1. Occipital artery. 2. Superior thyroid artery. 3. Thyrocervical trunk.

Nerve Supply

1. Accessory nerve: motor. 2. Anterior rami of the second and third cervical nerve: sensory.

SCM Action

1. Extension of the head at the atlanto-occipital joint. 2. Flexion of the cervical vertebrae. 3. Pulls the ipsilateral ear to the shoulder when the face is rotated in the opposite direction.

Operative Technique

1. Outline the paddle of skin to be employed, either superiorly or inferiorly based. 2. Elevate the skin muscle paddle from the deep fascia before performing the neck dissection. 3. Using 3-0 chromic sutures fix the underlying fascia muscle to the skin to avoid avulsion (dermal layer - not epidermis). 4. Rotate the paddle under the mandible to rest it in the defect. NB. There should be no tension at any point. 5. Suture the muscle tip to the wound to anchor the pedicle. 6. Suture the skin margins, again without tension. 7. The donor site is closed primarily, or using a rhomboid rotation flap.

Indications for Usage

A. SCM flap reconstruction of: 1. Tongue. 2. Floor of mouth. 3. Tonsillar fossa.

8 4. Esophageal patency.

Drawbacks

1. Limited range and size. 2. Variable covering ability secondary to loss of either superior or inferior blood supply. 3. Debate exists as to safety of this flap in conservation neck surgery. However, if the fascia is not violated by tumor, and nodes are "self-contained", the muscle may be used. 4. Partial epithelial loss over skin paddle is common (50%0.

Trapezius

Anatomy

This muscle has a broad base of origin. Fibers originate from the medial third of the superior nuchal line of the occipital bone, the external occipital protuberance, and the ligamentum nuchae. Further, fibers originate from the seventh cervical vertebrae and the spinous and supraspinous ligaments of all the thoracic vertebrae. The muscle fans far out to insert in essentially three bundles. The upper portion directs to the lateral third of the clavicle. The middle third fibers are directed to the acromion process horizontally, and the inferior fibers are directed upward and laterally to insert on the medial end of the spine of the scapula.

Arterial Supply

1. Ascending cervical artery. 2. Transverse cervical artery. 3. Suprascapular artery.

Nerve Supply

1. Spinal accessory nerve. 2. Third and fourth cervical nerve: sensory.

Trapezius Action

The various muscle bundles act in a coordinated effort. Subdivided, the upper fibers elevate the scapula, the middle fibers pull the scapula medially, and the lower fibers pull the medial border of the scapula downward. These efforts assist the serratus anterior muscle in the elevation of the arm.

Operative Technique

1. Positioning is very important. Place the ipsilateral arm across the chest with the side of the chest elevated. 2. Measure the defect carefully. Too much flap is rarely a problem. 3. The distance from the thyrocervical trunk to the defect will indicate the length available.

9 4. Skin and subcutaneous tissue are incised and trapezius muscle with fascia (including transverse cervical vessels) are elevated. NB: Full thickness of muscle must be elevated since the blood supply enters from the deep surface. 5. Blunt dissection will separate muscle bundles. NB: The venous drainage is superficial and should be well identified and preserved before arterial dissection. The vein (TCV) is found superficial to the omohyoid, while the artery is deep to it. 6. The donor site is undermined and the flap is swung forward. At this point the vascular pedicle to the thyrocervical trunk is the sole point of attachment. HANDLE WITH CARE! 7. The muscle and skin are sutured into place in the defect. 8. The donor site is usually closed primarily.

Indications for Usage

Reconstruction of:

1. Tongue. 2. Floor of the mouth. 3. Lateral pharynx. 4. Hypopharynx. 5. Neck skin (and opposite neck). 6. Mandible and soft tissue. 7. Esophagus.

Drawbacks

1. Sacrifice of the accessory nerve. 2. Bulkiness. 3. Donor site may require a skin graft. 4. Often the base of the flap is too thick for primary intraoral covering and requires a controlled orocutaneous fistula.

Pectoralis Major (PM)

Anatomy

This broad, flat, and fan-shaped muscle has its origin from the medial portion of the clavicle (horizontal fibers), the sternum, and the upper six costal cartilages. The fibers, after reaching maximum span over the chest wall, converge into a large tendon that attaches to the lateral tip of the bicipital groove of the humerus.

Arterial Supply

1. Thoracoacromial artery. 2. Lateral thoracic artery (nondominant).

10 Nerve Supply

1. Medial pectoral nerve. 2. Lateral pectoral nerve.

PM Action

The PM muscle bundles adduct the arm and medially rotate it. The clavicular fibers assist in the flexion of the arm.

Operative Technique

1. The paddle is outlined on the chest wall along the vascular strip. Place marks on the shoulder tip and xyphoid and join these points. The artery is drawn exiting from under the midportion of the clavicle perpendicular to this line. 2. Skin and subcutaneous tissue is incised along the lateral border of the paddle. 3. Muscle bundles are split and dissection is carried deep to the muscle to avoid injury to the vascular pedicle (include fascia). 4. Using a retractor, elevate the muscle and deep fascia for direct visualization of the neurovascular bundle. 5. Suture deep dermal layers to the underlying fascia with 3-0 chromic suture to avoid avulsion of the flap. 6. As the dissection is carried superiorly, keep the neurovascular pedicle in view at all times. 7. The infraclavicular attachments are separated. 8. The pectoral nerve is cut. 9. The flap is turned over the clavicle and placed in the reconstructive site. 10. The donor site is closed primarily and drained.

Indications for Use

Reconstruction of:

1. Base of tongue/anterior tongue. 2. Floor of mouth. 3. Pyriform sinus. 4. Esophageal defects. 5. Mandible and soft tissue. 6. Temporal bone resection site. 7. Orbital defects. 8. Neck skin defects. 9. Palate. 10. Tonsillar fossa.

Note: Paddle can be divided and folded onto itself to form an inner and outer closure.

11 Drawbacks

1. Pedicle rests on the clavicle which may cause decrease in vascularity. 2. Bulkiness. 3. Change in chest wall appearance, especially in younger women. 4. McFee's incision is necessary for tunneling flap - this may be hazardous in post- irradiated necks following previous radical neck dissection.

Latissimus Dorsi (LD)

Anatomy

The largest and first utilized of the myocutaneous flaps, this fan-shaped muscle arises from the posterior portion of the iliac crest, the lumbar fascia, and the spines of the lower six thoracic vertebrae (deep to the trapezius). Other muscle bundles arise from the lower three or four ribs and fibers have been recognized from the inferior angle of the scapula. All of these bundles converge to a single tendinous insertion. The tendon wraps around the teres major muscle and inserts to the floor of the bicipital groove of the humerus.

Arterial Supply

1. Thoracodorsal branch from the subscapular artery.

Nerve Supply

1. Thoracodorsal nerve: from the posterior cord of the brachial plexus.

LD Action

This broad, fan-shaped muscle is best appreciated in trained athletes (especially swimmers). It extends, adducts, and medially rotates the arm.

Operative Technique for Latissimus Dorsi Flap

1. Place the patient in a lateral decubitus position. 2. Draw the paddle obliquely along the long axis of the muscle with the lateral border on the lateral margin of the muscle. 3. Initial incision is begun in the upper lateral portion of the flap defining a place between the latissimus dorsi and the serratus anterior. 4. Dissect toward the axilla to identify the neurovascular bundle on the deep surface of the muscle. 5. Once the neurovascular pedicle is identified, free the remaining portion of the designed myocutaneous unit.

NB: Bleeding may be a problem if vessels to the teres major and serratus anterior are not identified and ligated.

12 6. The deep border of the pectoralis major is appreciated and a tunnel is created between the pectoralis major and pectoralis minor up to the clavicle. 7. The flap is pulled through this tunnel, over the clavicle, and deep to the neck flap. 8. If intraoral use is intended, the flap is directed deep to the mandible. 9. Suture the pectoralis fascia to the latissimus fascia to avoid sliding and potential compromise of the vascular pedicle.

Indications for Use

Reconstruction of:

1. Intraoral defects. 2. Intraoral and extraoral combined defects. 3. Temporal bone resection. 4. Orbital defects. 5. Nasal defects. 6. Scalp defects. 7. Frontoethmoid defects.

Drawbacks and Disadvantages

1. Requires change in patient position to reach the donor site. 2. The flap is tunneled through an area of the anterior chest wall which may be used as a donor site. 3. Attempts to incorporate rib (ninth) may lead to pneumothorax. NB: Any myocutaneous flap placed in a heavily irradiated field may break down at the point of attachment of the skin paddle and the radiated tissue. This, however, rarely has required surgical correction.

Complications of Myocutaneous Flaps

1. Loss of flap due to disruption of the vascular pedicle. 2. Loss of random skin flap (island) attached to an axial myocutaneous flap. 3. Skin slough. 4. Separation of suture line. 5. Infection: donor and recipient site. 6. Fistulae. 7. Flap too small to fill defect. NB: Most flaps that appear bulky initially after surgery, with the nerve cut, will shrink as the muscle atrophies (6-9 months). 8. Loss of muscle form and function from donor site. 9. Hematoma at the donor site: should be drained using Hemovac.

13 III. Cosmetic Surgery

Blepharoplasty

Preoperative Evaluation

1. Minimal ophthalmic evaluation includes visual acuity with a Snellen's eye chart, ocular motility, and ocular tension by palpation. In patients who have had previous eye disease or systemic disease suggesting retinal pathology an ophthalmology consultation is mandatory.

2. Upper lid:

a. Amount of redundant skin of the upper eyelid and inequality between each upper eyelid should be noted and mentioned to the patient. At the same time, hooding and brow ptosis should be evaluated and identified for the patient, counseling them that a blepharoplasty may not correct hooding and may exacerbate brow ptosis.

b. The eyelid crease from the supratarsal fold must measure 7-10 mm above the eyelash margin. If this crease in the central part of the eyelid is less than 7 mm above the lash margin, consideration must be given to performing an upper lid fixation blepharoplasty.

c. The presence or absence of fat in the medial and pretarsal compartments is evaluated for subsequent removal at surgery.

d. A bulge in the lateral upper eyelid usually is due to ptosis of the lacrimal gland.

3. Lower lid:

a. The pinch test to evaluate tonicity of the lower lid is performed by pulling the lower lid from the globe and observing its return to the original position. If the lid settles back and does not snap back, then consideration must be given to performing a lid-shortening procedure.

b. The presence or absence of scleral show and inequality between scleral show of each lower lid is mentioned to the patient if it should exist preoperatively. Should an inequality exist postoperatively, the patient will have been prepared for this particular cosmetic result.

c. The presence of pseudo-herniated fat in the three compartments of the lower lid is elevated by having the patient elevate the eyes and look superiorly. Palpation of the globe and observation of the transmitted pulse through the pseudo-herniated fat also will identify the fat that must be removed.

4. A four-lid blepharoplasty will not correct brow ptosis, hooding, or crows'-feet.

14 Surgical Procedures

Upper Lid

1. The lower incision is made in the supratarsal fold and may run laterally in a crow's- foot a distance of not more than 15-20 mm from the lateral canthus. Preferably it should lie within the margin of the bony orbit.

2. The upper incision lies at the junction in the change in texture of the upper eyelid skin and brow. Pinching the skin to be excised along the proposed incisions will help prevent injudicious skin excision and postoperative lagophthalmos.

3. Thick upper eyelids are treated by removing a strip of the orbicularis muscle that may be as wide as the width of skin excised. Fat is then removed from the pretarsal and medial pockets. The fat of the medial pocket is whiter and of different consistency than the pretarsal fat.

4. A bulge in the lateral quadrant of the upper eyelid is due to a ptotic lacrimal gland. The fullness may be corrected by suturing the lacrimal gland with a 5-0 clear nylon suture to the periosteum of the lacrimal fossa.

Aponeurosis Fixation Upper Lid Blepharoplasty

1. Indications: a. Males. b. Young females 45 or younger with thick skin. c. Sometimes in middle-aged females 45-60. d. Never in elderly females. 2. Preoperative counseling must include information about transient ptosis and difficulty looking upward for up to 3 months after surgery. 3. The upper incision is made 12 mm above the lash line in the central part of the lid in females, and 10 mm above the lash line in males. After opening the septum and removing the preaponeurotic fat, the levator aponeurosis is identified. The orbicularis oculi muscle is then trimmed flush with the skin of the lower eyelid incision and is not resected below the skin margin. Five to seven sutures of 6-0 clear nylon are made through the orbicularis oculi muscle and levator aponeurosis. The skin is then closed with a running suture. 4. Extreme care must be paid to marking and creating equal and symmetrical supratarsal folds.

Lower Lid Blepharoplasty - Skin Flap

1. Indicated in patients with excessive skin laxity. An incision is made 2 mm below the lash line and is carried laterally in a crow's-foot to the bony orbital margin. 2. A minimum of 5 mm of skin must lie between the upper and lower eyelid incisions to prevent webbing and flap edema. 3. The skin is redraped and the patient is asked to open the mouth and look upward as the skin is redraped to the new concavity of the lower eyelid following fat removal. After

15 marking out the amount of skin to be excised, slightly less than the expected amount of skin excision should be carried out to reduce the likelihood of a postoperative ectropion.

Lower Lid Blepharoplasty - Skin Muscle Flap

1. This operation is useful for patients with pseudo-herniated fat and relatively smooth lower eyelid skin. 2. The incision is made as before, 2 mm below the lash line, and laterally carried down to the periosteum of the orbit. The orbicularis muscle is separated by blunt dissection from the soft tissues of the orbit. The skin muscle flap is separated from the previous skin incision with scissors beveled to preserve the tarsal plate and lash follicles. Gentle pressure on the globe will reveal the pockets of fat that need to be resected. Following resection of the orbital fat, the skin muscle flap is redraped and again the patient is asked to open the mouth widely and look upward as the flap is repositioned prior to marking for excision. After excision of the full thickness skin and muscle, a second 1-2 mm of orbicularis oculi muscle is removed from the skin flap to prevent postoperative bulging of the muscle along the suture line.

Complications

Serious complications following blepharoplasty are rare.

Hematoma

1. Usually clears in time. 2. If clot liquefies, drainag through a small stab incision and milking the clot will suffice. 3. Large hematomas with loss of visual acuity will produce deep unilateral eye pain. This must be handled with immediate removal of sutures from the incision to facilitate decompression of the orbit. a. Immediate ophthalmology consultation. b. 2 g mannitol IV, and IV acetazolamide (Diamox). c. May develop up to 1 week after surgery, but usually have been repaired within 12- 24 hours after surgery. d. Incidence is 1:25,000-50,000 cases. e. There has been one reported case of bilateral blindness.

Milia

1. Most frequent complication. 2. They develop along the suture tracks and are treated by pinpoint cautery or marsupialization with a 25 gauge needle.

Lagophthalmos

1. Inability to completely close the eyes is relatively common for a period of several weeks following blepharoplasty. As the lids and brows gradually settle, this usually resolves spontaneously.

16 2. Severe lagophthalmos with corneal drying is due to overzealous excision of the upper eyelid skin and should be treated with a full-thickness skin graft.

Ectropion

1. Minimal eversion of the lower eyelid skin is also relatively common following lower lid blepharoplasty and will resolve as the edema and induration subside within the first week or two following blepharoplasty. 2. Severe ectropion due to scarring or overzealous excision of the lower eyelid is treated conservatively for several months with taping and forceful eyelid closure. a. If the ectropion fails to resolve, full-thickness skin graft from the upper eyelid skin (if sufficient quantities exist) is the donor site of choice. b. Full-thickness skin grafts from the postauricular area and supraclavicular fossa provide the next best texture and tissue match for the lower eyelid skin. c. A horizontal lid shortening procedure with skin grafting may be necessary to correct the ectropion in atonic lids.

Blindness

1. This complication almost always follows fat removal and occurs in 1:25,000- 1:50,000 cases. 2. Postoperative instructions should include frequent checking of the visual acuity by patient, nurses, and family. 3. If the patieent complains of deep, unilateral eye pain that is similar to the pain produced with teasing the fat from the orbit, the surgeon should be notified immediately. 4. Sudden onset of pain and blindness has been reported up to 5 days following a blepharoplasty. Therefore, the patient should be instructed to rest and recover from surgery without returning to normal activities for a minimum of 2 weeks.

Hooding of the Lateral Canthus

1. Develops when the upper and lower eyelid incisions are too close together. 2. The incisions should be separated by at least 5 mm.

Dry Eye

1. Blepharoplasty may exacerbate a preexisting lacrimal disorder. 2. Schirmer's testing preoperatively will identify those patients who should have a conservative skin excision of the upper eyelid skin.

Facelift

Preoperative Evaluation

A. The facelift operation needs to be tailored to the pathologic anatomy causing the cosmetic deformity for which the patient seeks consultation. B. A preoperative classification of the cervical area enables the surgeon to tailor the operation to each patient.

17 1. Class I is a patient with minimal cosmetic deformity who should either be advised against having cosmetic surgery or may have a "prophylactic" facelift with skin undermining to maintain the present visage. 2. Class II is a patient with skin laxity only. Treatment involves wide undermining and plication of the subcutaneous muscular aponeurotic system (SMAS) and posterior border of the platysma muscle. 3. Class III patient has excessive fat in the submandibular and/or submental areas that require sculpturing. a. A submental incision is required. b. Submental lipectomy which is removal of fat deep to the platysma muscle in the submental triangle to expose the mylohyoid muscle should be done very carefully to avoid the hollowed-out appearance in the submental area. Fat usually is removed on top of the platysma and between its medial borders. c. Removal of fat deep to the platysma muscle any distance from the midline increases the likelihood of injuring the marginal branch of the facial nerve. 4. Class IV is the patient with anterior banding of the platysma muscle that is either present in repose or accentuated by voluntary contraction. a. Plication, excision, and creation into flaps of the medial borders of the platysma muscle will remove this stigmata of the aging neck. b. Complete horizontal sectioning of the platysma muscle at the level of the hyoid bone, or lower, is advocated by some to create a sling of the platysma muscle as it is sutured in the midline and created into flaps and sutured posteriorly along its posterior border to the sternocleidomastoid fascia. 1) Complete horizontal sectioning of the platysma muscle, if done at a level higher that the hyoid bone, may result in rolled-up borders of the platysma muscle which are difficult to camouflage. 2) The platysma muscle may be safely sectioned by first undermining it and then squezing the muscle with the hemostat prior to clamp closure while observing the corner of the mouth. If no movement occurs, sectioning below the clamp after it is closed will prevent injury to the mandibular branch of the facial nerve. c. Ptosis of the submaxillary glands may be accentuated and increased by complete horizontal sectioning of the platysma muscle. d. Plication of the medial borders of the platysma muscle with a permanent buried suture will not only give support to the submental area but will prevent the hollowed-out appearance in the submental area whn a submental lipectomy has been done. 5. Class V neck is the patient with acquired retrognathia or congenital microgenia who needs a chin implant at the same time as the cervical facial rhytidectomy. a. The implant may be placed through the submental incision. b. The increase in projection of the pognion will greatly enhance the postoperative cosmetic result and the cervicomental contour. 6. Class VI is the patient with a low-lying hyoid bone. a. Ideally the hyoid bone should lie at or above the fourth cervical vertebra. b. Preoperative identification of this patient will enhance preoperative counseling to warn the patient of a less-than-optimum postoperative cervicomental contour. C. Patients who are heavy smokers should have a conservative operation as they tend to bleed, heal poorly, and are susceptible to skin slough. D. The facelift operation will improve the lower third of the face and upper one-half of the neck. It will not improve the nasolabial fold area.

18 Operative Technique

A. The facelift operation is basically divided into four flaps: temporal, preauricular, cervical, and postauricular. 1. These flaps are at different levels with temporal and occipital flaps being deep to preserve the hair follicles while the preauricular and cervical flaps are superficial to the SMAS. B. The danger zone are where vital structures may be injured. 1. The zygomaticotemporal branch of the facial nerve begins to run very superficially over the zygomatic arch and runs in a line from 0.5 cm below the tragus diagonally to a point 1.5 cm lateral to the eyebrow. a. Elevation of the temporal flap anterior to the hairline must be deep to the frontalis muscle and on top of the periosteum to avoid injury to the superficial level of the temporal nerve. b. Below the zygomatic arch, elevation of flaps to the lateral canthal area are possible, but must be superficial to the SMAS to avoid injuring the nerve. 2. The marginal mandibular branch of the facial nerve lies in the fascia of the submaxillary gland. At the level of the notch in the mandible for the facial artery and vein, the nerve begins to course superiorly to, and subsequently lie above, the horizontal ramus of the mandible deep to the platysma muscle. a. Posterior to the notch of the facial artery there is a relatively thick cushion of tissue protecting the facial nerve and its branches. b. Anterior to the notch of the facial artery, the nerves run much more superficially beneath the SMAS and the platysma muscle. 3. The greater auricular nerve lies 6.5 cm below the sternal meatus of the ear in the midportion of the sternocleidomastoid muscle. a. As dissection begins posteriorly and runs over the sternocleidomastoid muscle, dissection must be superficial to leave the fascia overlying the sternocleidomastoid muscle intact to protect the greater auricular nerve. b. Severing this nerve will result in a numb ear postoperatively and if recognized at surgery should be reanastomosed and buried in the sternocleidomastoid muscle to prevent neuroma formation. C. The conservative or minimally undermined facelift. 1. Flap elevation is limited to 2.0-2.5 cm. 2. Ethibond 2-0 sutures are used to plicate the SMAS and posterior border of the platysma muscle posterosuperiorly on the perichondrium of the tragus and fascia of the sternocleidomastoid muscle. 3. The skin flaps are then redraped and trimmed with slightly more tension than allowed with wider undermining since the flaps have such an excellent blood supply. 4. This technique has fewer complications with bleeding, skin slough, and nerve damage. 5. Patients who have a class III, IV, or V neck will require submental and submandibular sculpturing in addition to the minimally undermined facelift to adequately correct the cosmetic deformity. D. The widely undermined facelift. 1. Flap elevation and undermining may be extended to the nasolabial folds and connected to the undermining in the submental area.

19 2. The SMAS and posterior border of the platysma muscle are either plicated posterosuperiorly with buried 2-0 Ethibond sutures or the SMAS is excised beginning 1 cm below the zygomatic arch and 1 cm in front of the tragus and carried inferiorly to connect with the platysma muscle. a. Following elevation of the SMAS layer to the anterior border of the parotid, the flap is redraped posterosuperiorly, trimmed, and then sutured to the pretragal and postauricular fascia with 4-0 Mersilene and/or 4-0 Dexon sutures. 3. When indicated, fat is removed along the inferior border of the mandible on top of the platysma muscle to define the horizontal ramus of the mandible. a. Patients who have an ill-defined platysma muscle must be handled conservatively to prevent damage to the mandibular nerve. b. Obese individuals who require submental and submandibular sculpturing will require tapering of the fat excision in the inferior aspect of the neck to prevent a sharp cutoff. 4. The skin flaps then are redraped in a posterosuperior direction that is parallel to a line drawn from the tragus to Darwin's tubercle. 5. Excessive tension on the flaps must be avoided in these widely undermined facelifts to prevent ischemia and skin necrosis. 6. If a submental incision is used, little if any skin is excised since the skin is redraped superiorly and is under marked tension. a. The submental incision is placed posterior to the first submental crease, but not any lower than the hyoid bone. b. The witch's chin deformity with a ptotic chin may be alleviated by elevating the skin from the first submental crease and filling the area with a fat flap.

Complication

Hematoma

1. The incidence of hematoma varies from 3.0-15.9%. a. Major hematomas requiring evacuation occur approximately 3-4% of the time. b. Minor hematomas that will resolve spontaneously or require aspiration may run as high as 15% in selected series. c. The average incidence of hematoma formation is 7%. 2. The diagnosis of hematoma is based upon unilateral facial pain, swelling, and buccal ecchymosis. a. When suspected, immediate removal of the dressing and inspection of the flaps is mandatory. b. When diagnosed, the sutures are removed immediately to take tension off the skin flaps and the clot extracted. 1) Major hematomas will require general anesthesia and return of the patient to the operating room. 2) Minor hematomas may be managed by intravenous sedation and irrigation of the wound with normal saline until clear.

Skin Necrosis

1. The incidence of large and small skin necrosis may run as high as 25%, but usually is reported to occur in 1-3% of the cases.

20 2. The most common site is postauricular due to excessive tension on the flaps. 3. WHen diagnosed, conservative therapy without excision is the treatment of choice as the wound will contract and most often give a satisfactory cosmetic result. 4. When wide scars or large areas of skin slough persist, serial scar excision will adequately handle the cosmetic deformity. Skin grafting rarely is required.

Nerve Injury

1. The most frequently injured nerve is the greater auricular nerve. a. If the patient develops delayed postoperative pain due to severance of the greater auricular nerve, re-exploration and anastomosis of the severed ends frequently will alleviate the trigger-type pain. b. Immediate, severe postoperative auricular pain may be due to plication sutures that lie in or across the greater auricular nerve and usually will resolve in 6-8 weeks.

Infection

1. The excellent vasculature of the face fortunately makes this an unusual complication. 2. It has been reported with a slightly higher incidence with Penrose drains as opposed to suction drains. 3. Treatment with incision and drainage and appropriate antibiotics usually will resolve the infection without serious sequelae.

Auricular Deformities

1. Excessive tension on the lobule at closure will result in a "pixie ear". 2. Correction of this deformity is managed by redraping the skin superiorly in front of and behind the ear so that the lobule hangs free.

Submental Depression

1. Injudicious removal of fat deep to the platysma muscle may leave the cobra deformity. 2. A layer of fat left on the skin flap will prevent this from developing and plication of the anterior borders of the platysma muscle similarly will avoid the sunken look.

Alopecia

1. Superficial undermining of the flaps in the temporal and postauricular area will damage the hair follicles. 2. Excessive tension on these flaps will result similarly in hair loss. 3. Male patients must be told preoperatively that the sideburns will be reduced in width as the incision is made halfway between the tragus and hair-bearing skin of the face. In addition, they must be told they will have to shave behind their ears postoperatively. 4. When large areas exist, hair transplantation or localized advancement flaps will correct the bald areas.

21 Scar Revision

General Principles

A. Relaxed skin tension lines (RSTL) and their direction is of paramount importance in the revision of linear scars. 1. The RSTL are different from Langer's lines which are the lines of skin tension in rigor mortis. Langer's lines in a living person are found when the supine position is assumed with the extremities in extension. 2. Relaxed skin tension lines are the grooves and ridges that follow the direction of the greatest pull in a relaxed attitude, hence these may be different from Langer's lines. 3. When the body is placed in a relaxed attitude, the skin tension will follow only one specific direction, that of the RSTL direction. a. Relaxed skin tension lines are similar to wrinkle lines in most, but not all instances. b. Wrinkle lines are influenced by muscle pull. c. Muscle pull may accentuate the relaxed skin tension lines by relaxing the skin perpendicular to them or it may produce folds that do not follow the RSTL. 4. The long axis of excision of tissue should followe the RSTL. 5. The RSTL can be found by relaxing the skin of the region. a. Passive manipulation by pinching the skin will form ridges and furrows that extend for a greater distance in the direction of the RSTL than they do when a similar maneuver is made at angles to the RSTL. b. Pinching in the wrong direction will result in distorted crumpling. 6. The RSTL in body apertures (the ear, nose, mouth) extend perpendicularly or radially from their centers. B. A scar reaches maturation ion 9-12 months. 1. An incision that is sutured will reach its maximum breaking strength at six weeks. 2. While the strength of the wound will not change after 6 weeks, there is a continual degradation and synthesis of collagen in the scar as the tension of the wound edges determines the width and thickness of the scar that subsequently develops. 3. Therefore, revision of scars should not be undertaken prior to a minimum of 6 months, and preferably 1 year to allow complete maturation.

Operative Technique

Simple Excision with Fusiform Revision

1. Scars no longer than 2 cm in length. 2. Scars that run along the RSTL. 3. Beveling of the incision away from the wound as it extends to the deeper layers will aid in subsequent eversion of the wound edges on closure. a. A permanent, nonabsorbable suture of 5-0 clear nylon placed through the dermis to evert the skin edges by closing the dermal layer will guarantee the edges of the wound to be approximated without tension for several weeks or months. b. A subcuticular 6-0 nylon suture that approximates the everted skin edges will yield maximum cosmetic result. c. Interrupted sutures that are removed in 3-5 days to prevent permanent suture marks also will give a satisfactory result.

22 Serial Excision of Wide Scars

1. This method involves resecting a wide scar or lesion or skin graft in stages. 2. The area to be excised is reduced with each stage excision until a satisfactory linear scar remains. 3. This method takes advantage of the elasticity of the skin and subsequent stages are planned at 3-6 month intervals when clinically indicated.

W-Plasty and Zigzag Plasty

1. Linear scars over 2 cm in length that do not lie in the relaxed skin tension lines may be conspicuous because the eye as it perceives a long scar is able to follow its direction and predict its course. a. By breaking up a long scar into short, broken-line closures, the eye is not able to follow these breaks and the scar is thus camouflaged. 2. The W-plasty is the simplest of the broken-line closure techniques. a. Small triangular flaps are incised on each side of the scar so that they interdigitate following excision and subsequent closure. b. The sides of the individual triangular flaps should not be longer than 6.5 mm and the base no wider than 6 mm. c. All incisions are made at right angles to the skin. d. Undermining of the skin is made so that the thickness of the flaps at the tip is the same as the base. e. Subcutaneous and intradermal interrupted sutures are used to close the dead space and to relieve tension on the skin suture line. f. Small, half-buried mattress sutures secure the tips of the flaps to their receptor angles. 3. A zigzag-plasty. a. In addition to the W-plasty described, small rectangles and squares mixed between the triangles of the W-plasty will break the continuity of the triangle. b. Rectangles and squares on one side correspond with those in size on the opposite side of the skin to allow them to interdigitate when advanced at closure. c. Because of the marked irregularity of the closure line, a better camouflage is obtained. d. Flaps of the zigzag-plasty should not be larger than 4-5 mm and are readily made with a number 11 knife blade. e. Undermining and wound closure is similar to the W-plasty.

Z-Plasty

1. A type of transposition flap. 2. The Z-plasty consists of a central limb with arms extending from each end in opposite directions, forming an angle with a central limb of 60° or less. 3. The central limb in both arms are of equal length. 4. Two triangular flaps are created which when transposed result in a change of the direction of the central limb and a redistribution of tension. 5. The change of direction depends upon the size of the angles of the Z-plasty.

23 a. If both angles of the Z-plasty are 60°, the central limb will rotate 90° when the flaps are transposed. b. The smaller the angle of the Z-plasty, the smaller the rotation of the central limb. 6. To predict the direction of the central limb after transposition, an imaginary line connecting the ends of both arms to the Z-plasty is made. 7. The correct direction for the arms of the Z-plasty would be one that parallels the tension lines. 8. The advantages of the Z-plasty over the broken line closures. a. It can release or prevent linear scar contractions. b. It can change the long axis of the scar. c. It can redistribute tension in an area. d. It uses all available tissue. 9. The primary disadvantages of a Z-plasty. a. It increases total scar length 200%. b. The tip areas of the triangle or flaps tend to become depressed. c. The angles tend to elevate causing differences in contour of the wound edges. 10. The W-plasty, zigzag plasty and other broken line closure techniques give better results than the Z-plasty for most facial scars.

Ancillary Procedures for Scar Revision

1. Dermabrasion. a. Minor elevations or depressions along incision lines may be corrected by superficial dermabrasion. 2. Shave excision with a razor blade to "plane" the skin also may be used to revise minor elevations and depressions. 3. Collagen injections subsequently may prove to be another tool in the armamentarium for correcting and augmenting small irregular depressions. 4. Hypertrophic scars and keloids are treated with intralesional steroids of 10 mg/mL.

24 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 23: Syndromes and Eponyms

Syndromes and Diseases

Adult Respiratory Distress Syndrome (ARDS)

This syndrome is characterized by a delay in onset 912-24 hours) following injury, shock, and/or successful resuscitative effort. Septic shock, extrathoracic trauma, CNS pathology, fat embolism, oxygen toxicity, head and facial injuries, and massive blood transfusions can lead to ARDS. It is characterized by hypoxia and pulmonary infiltrates secondary to increased pulmonary vascular permeability and/or microvascular hemorrhage.

Adie's Syndrome

Adie's syndrome is characterized by decreased pupillary reaction and deep tendon reflex. The etiology is unknown.

Albright's Syndrome

Polyostotic fibrous dysplasia usually occurs early in life as multicentric lesions involving the long bones and bones of the face and skull, with scattered skin lesions similar to melanotic cafe-au-lait spots and precocious puberty in females. Frequently there is an elevation of serum alkaline phosphatase as well as endocrine abnormalities.

Aldrich's Syndrome

Thrombocytopenia, eczema, and recurrent infections in the first year of life. It is inherited through a sex-linked recessive gene. The bleeding time is prolonged, the platelet count is decreased, and the bone marrow megakaryocytes are normal in number.

Amalric's Syndrome

Granular macular pigment epitheliopathy (foveal dystrophy) associated with sensorineural hearing loss. Visual acuity is usually normal. This syndrome may be a genetic disorder, or it may be the result of an intrauterine rubell infection.

Ascher's Syndrome

A combination of blepharochalasis, double lip, and goiter.

Auriculotemporal Syndrome (Frey's Syndrome)

This syndrome is characterized by localized flushing and sweating of the ear and cheek region in response to eating. It usually occurs after parotidectomy. It is assumed that following parotidectomy the parasympathetic fibers of the IX nerve innervate the sweat glands. It has been estimated that 20% of parotidectomy in children results in this disorder.

1 Avellis' Syndrome

Unilateral paralysis of the larynx and velum palati, with contralateral loss of pain and temperature sensitivity in the parts below the larynx characterize Avellis' syndrome. This syndrome is caused by involvement of the nucleus ambiguus or the vagus nerve along with the cranial portion of the XI nerve.

Babinski-Nageotte Syndrome

This syndrome is caused by multiple or scattered lesions, chiefly in the distribution of the vertebral artery. Ipsilateral paralysis of the soft palate, larynx, pharynx, and sometimes tongue will occur. There is also ipsilateral loss of taste on the posterior third of the tongue, loss of pain and temperature sensation around the face, cerebellar asynergia, Horner's syndrome with contalateral spastic hemiplegia, and loss of proprioceptive and tactile sensation.

Baelz's Syndrome

Painless papules at the openings of the ducts of the mucous glands of the lips, with free exudation of mucous are characteristic. Congenital and familial forms are precancerous. Acquired forms are benign and caused by irritating substances.

Barany's Syndrome

This is a combination of unilateral headache in the back of the head, periodic ipsilateral deafness (alternating with periods of unaffected hearing), vertigo, and tinnitus. The syndrome complex may be corrected by induced nystagmus.

Barclay-Baron Disease

Vallecular dysphagia.

Barre-Lieou Syndrome

Occipital headache, vertigo, tinnitus, vasomotor disorders, and facial spasms due to irritation of the sympathetic plexus around the vertebral artery in rheumatic disorders of the cervical spine are characteristic. It is also know as cervical migraine.

Barrett's Syndrome

Barrett's syndrome is characterized by esophagitis due to change of epithelium of the esophagus.

Barsony-Polgar Syndrome

A diffuse esophageal spasm caused by disruption of the peristaltic waves by an irregular contraction, resulting in dysphagia and regurgitation is evidence for this syndrome. It most commonly affects excitable elderly persons.

2 Basal Cell Nevoid Syndrome

This familial syndrome, non-sex-linked, autosomal dominant with high penetrance and variable expressivity, manifests itself early in life. It appears as multiple nevoid basal cell epitheliomas of the skin, cysts of the jaw, abnormal ribs and metacarpal bones, frontal bossing, and dorsal scoliosis. Endocrine abnormalities have been reported and it has been associated with medulloblastoma. The cysts in the jaw, present only in the maxilla and mandible, are destructive to the bone. The basal cell epitheliomas are excised as necessary and the cysts in the jaw rarely recur after complete enucleation.

Bayford Autenrieth Dysphagia (Arkin's Disease)

Dysphagia lusoria is said to be secondary to esophageal compression from an aberrant right subclavian artery.

Beckwith's Syndrome

This is a congenital disorder characterized by macroglossia, omphalocele, hypoglycemia, pancreatic hyperplasia, noncystic renal hyperplasia, and cytomegaly of the fetal adrenal cortex.

Behcet's Syndrome

Of unknown etiology, this disease runs a protracted course with periods of relapse and remission. It manifests as indolent ulcers of the mucous membrane and skin, stomatitis, as well as anogenital ulceration, iritis, and conjuctivitis. No definitive cure is known though steroids will help.

Besnier-Beck-Schaumann's Syndrome

Sarcoidosis.

Bogorad's Syndrome

This also is known as the syndrome of crocodile tears characteriuzed by residual facial paralysis with profuse lacrimation during eating. It is caused by a misdirection of regenerating fibers to the lacrimal gland instead of to the salivary gland.

Bonnet's Syndrome

Sudden trigeminal neuralgia accompanied by a Horner's syndrome and vasomotor disorders in the area supplied by the trigeminal nerve are manifestations of this syndrome.

Bonnier's Syndrome

This syndrome is caused by a lesion of Deiter's nucleus and its connection. Its symptoms include ocular disturbances, i.e. paralysis of accommodation, nystagmus, diplopia, deafness, nausea, thirst, anorexia, as well as other symptoms referable to involvement of the

3 vagal centers, cranial nerves VIII, IX, X, and XI, and the lateral vestibular nucleus. It can simulate Ménière's disease.

Bourneville's Syndrome

This is a familial disorder. Its symptoms include polyps of the skin, harelip, moles, spina bifida, and microcephaly.

Bowen's Disease

It is a precancerous dermatosis characterized by the development of pinkish or brownish papules covered with a thickened horny layer. Histologically, it shows hyperchromatic acanthotic cells with multinucleated giant cells. Mitoses are frequently observed.

Briquet's Syndrome

Briquet's syndrome is characterized by a shortness of breath and aphonia due to hysteric paralysis of the diaphragm.

Brissaud-Marie Syndrome

Unilateral spasm of the tongue and lips of a hysteric nature are characteristic.

Brun's Syndrome

Vertigo, headache, vomiting, and visual disturbances due to an obstruction of CSF flow during positional changes of the head are seen. The main causes of this syndrome include cysts and cysticercosis of the fourth ventricle as well as tumors of the midline cerebellum and third ventricle.

Burckhardt's Dermatitis

This dermatitis appears as an eruption of the external ear consisting of red papules and vesicles after exposure to sunlight. The rash usually resolves spontaneously.

Caffey's Disease (Infantile Cortical Hyperostosis)

Of family tendency, its onset is usually in the first year of life. It is characterized by hyperirritability, fever, and hard nonpitting edema that overlies the cortical hyperostosis. Pathologically, it involves the loss of periosteum with acute inflammatory involvement of the intratrabecular bone and the overlying soft tissue. Treatment is supportive consisting of steroids and antibiotics. The prognosis is good. The mandible is the most frequently involved site.

4 Caisson Disease

This symptom complex occurs in men working in high air pressures when they are returned too suddenly to normal atmospheric pressure. Similar symptoms may occur in fliers when they suddenly ascend to high altitudes unprotected by counterpressure. It results from the escape from solution in the body fluids of bubbles (mainly nitrogen) originally absorbed at higher pressure. Symptoms include headache, pain in the epigastrium, sinuses, tooth sockets, itchy skin, vertigo, dyspnea, coughing, nausea, vomiting, and sometimes paralysis. Peripheral circulatory collapse may be present. Nitrogen bubbles have been found in the white matter of the spinal cord. It also can injure the inner ear through the necrosis of the organ of Corti. There is a question of rupture of the round window membrane; hemotympanum and eustachian tube obstruction may occur.

Campomelic Syndrome (Greek = curvature of the extremities)

The syndrome is characterized by dwarfism, craniofacial anomalies, bowing of the tibia and femur, with malformation of other bones. The patient has cutaneous dimpling overlying the tibial bend, respiratory distress is common and the patient has an early demise in the first few months of life. In the otolaryngologic area the patient exhibits prominent forehead with flat facies with a broad nasal bridge, and low-set ears, cleft palate, mandibular hypoplasia, tracheobronchial malacia which contributes to the respiratory distress, and neonatal death. Histologically, two temporal bone observations showed defective endochondral ossification with no cartilage cells in the endochondral layer of the otic capsule. The cochlea was shortened and flattened presenting a scala communis. The vestibule and the semicircular canal were deformed by bone invasion.

This syndrome is often of unknown etiology although some believe that it is autosomal recessive. Others believe that it may be due to an exogenous cause.

Cannon's Nevus

This is an autosomal dominant disorder characterized by spongy white lesions of the oral and nasal mucosa. The lesions are asymptomatic and may be found from the newborn period, with increasing severity until adolescence. The histologic picture is that of keratosis, acanthosis, and parakeratosis.

Carcinoid Syndrome

The symptoms include episodic flushing, diarrhea, and ascites. The tumor secretes serotonin. The treatment is wide excision. The tumor may give a positive DOPA reaction.

Carotid Sinus Syndrome (Charcot-Weiss-Barber Syndrome)

When the carotid sinus is abnormally sensitive, slight pressure upon it causes a marked fall in blood pressure due to vasodilation and cardiac slowing. Symptoms include syncope, convulsions, and heart block.

5 Cavernous Sinus Syndrome

The cavernous sinus receives drainage from the upper lip, nose, sinuses, nasopharynx, pharynx, and orbits. It drains into the inferior petrosal sinus which in turn drains into the internal jugular vein. The cavernous sinus syndrome is caused by thrombosis of the cavernous intracranial sinus, 80% of which is fatal. The symptoms include orbital pain (V1) with venous congestion of the retina, lids, and conjunctiva. The eyes are proptosed with exophthalmos. The patient has photophobia and involvement of nerves II, III, IV, and V1. The treatment of choice is anticoagulation and antibiotics. The most common cause of cavernous sinus thrombosis is ethmoiditis. The ophthalmic vein and artery are involved as well. The nerves and veins are lateral to the cavernous sinus while the internal carotid artery is medial to it.

Cestan-Chenais Syndrome

This is caused by occlusion of the vertebral artery below the point of origin of the posteroinferior cerebellar artery. There is paralysis of the soft palate, pharynx, and larynx; ipsilateral cerebellar asynergia; and Horner's syndrome. There is contralateral hemiplegia and diminished proprioception and tactile sensation.

Champion-Cregah-Klein Syndrome

A familial syndrome consisting of popliteal webbing, cleft lip, cleft palate, lower lip fistula, syndactyly, onychodysplasia, and pes equinovarus.

Chapple's Syndrome

This is a disorder seen in the newborn with unilateral facial weakness or paralysis in conjunction with comparable weaknes or paralysis of the contralateral vocal cord and/or muscles of deglutition. This disorder is secondary to lateral flexion of the head in utero, which compresses the thyroid cartilage against the hyoid and/or cricoid cartilages thereby injuring the recurrent or superior laryngeal nerves, or both.

Chediak-Higashi Syndrome

This is the result of an autosomal recessive trait characterized by albinism, photophobia, nystagmus, hepatosplenomegaly, anomalous cellular granules, and development of lymphoma. These patients usually die in childhood of fulminant infections.

Cleft Lip-Palate and Congenital Lip Fistulas

This syndrome is transmitted in an autosomal-dominant manner with 80% penetrance and occurs in 1:100,000 live births. Usually bilateral, symmetrically located depressions are noted on the vermillion portion of the lower lip, and communicate with the underlying minor salivary glands. The lip pits may be an isolated finding (33%) or found with cleft lip-palate (67% of cases). Associated anomalies of the extremities may include talipes equinovarus, syndactyly and popliteal pterygia - Champion-Cregah-Kelin syndrome. Congenital lip pits have also been seen in association with oral-facial-digital syndrome.

6 Cogan's Syndrome

Nonsyphilitic interstitial keratitis and vestibulo-auditory symptoms are characteristic of this syndrome. Interstitial keratitis gives rise to rapid visual loss. Symptoms include episodic severe vertigo accompanied by tinnitus, spontaneous nystagmus, atacia, and progressive sensorineural hearing loss. There are remissions and exacerbations. It is believed to be related to periarteritis nodosa. Eosinophilia has been reported in this entity. Pathologically, it is a degeneration of the vestibular and spiral ganglia with edema of the membranous cochlea, semicircular canals, and inflammation of the spiral ligament. Treatment with steroids has been advocated.

Collet-Sicard Syndrome

The IX, X, XI, and XII nerves are involved with normal sympathetic nerves. The etiology is usually a meningioma or other lesion involving the nerves in the posterior cranial fossa.

Costen's Syndrome

Costen's syndrome is a temporal-mandibular joint abnormality, usually due to impaired bite and characterized by tinnitus, vertigo, pain in the frontal, parietal, and occipital areas with a blocked feeling and pain in the ear. After a careful work-up to rule out other abnormalities, the patient is treated with aspirin, heat, and slow exercise of the joint. An orthodontist may help the patient. The TMJ differs from other joints by the presence of avascular fibrous tissue covering the articulating surfaces with an interposed meniscus diving the joint into upper and lower compartments. The right and left TMJs act as one functional unit. The condyle is made up of spongy bone with marrow and a growth center. The condyle articulates with the glenoid fossa of the temporal bone (squamosa). The squamotympanic fissure separates the fossa from the tympanic bone. The joint is a ginglymo-arthroidal joint with hinge and transverse movements. The key supporting ligament of the TMJ is the temporomandibular ligament. The boundaries of the glenoid fossa are:

Anterior - margins of the articular eminence Posterior - squamosotympanic fissure Lateral - zygomatic process of the temporal bone Medial - temporal spine.

The TMJ derives its nourishment from the synovial membrane which is richly vascularized and produces a mucinous-like substance. The joint has a gliding motion between the meniscus and the temporal bone (upper compartment) while it has a hinge motion between the disc and the condyle (lower compartment). It is innervated by the auriculotemporal nerve, masseter nerve, lateral pterygoid nerve and the temporal nerve. It is supplied by the superficial temporal artery and the anterior tympanic branch of the internal maxillary artery. The lateral pterygoid muscle protracts the jaw while the masseter, medial pterygoid, and temporalis muscles act as elevators. All these muscles are innervated by V3 (see Chapter on Facial Trauma for muscles of the mandible). The sphenomandibular and stylomandibular ligaments have no function in the TMJ articulation.

7 Cowden's Syndrome

A familial syndrome characterized by adenoid facies, hypoplasia of the mandible and maxilla, high-arched palate, hypoplasia of the soft palate and uvula, microstomia, papillomatosis of the lips and pharynx, scrotal tongue, multiple thyroid adenomas, bilateral breast hypertrophy, pectus excavatum, liver and CNS abnormalities.

Cri du Chat Syndrome

A condition caused by a B group chromosome with a short arm, its symptoms are mental retardation, respiratory stridor, microcephaly, hypertelorism, midline oral clefts, and laryngomalacia with poor approximation of the posterior vocal cords.

Crouzon's Disease (see Chap. 9)

Curtius' Syndrome

This is a form of hypertrophy that may involve a single small part of the body, or an entire system (i.e. muscular, nervous, or skeletal systems). It is also known as congenital facial hypertrophy.

Dandy's Syndrome

Oscillopsia or jumbling of the panorama common in patients after bilateral labyrinthectomy is characteristic of this syndrome. These patients are unable to focus while walking or moving.

Darier's Disease (Keratosis Follicularis)

Autosomal dominant, this skin disorder of the external auditory canal is characterized by keratotic debris in the canal. Some investigators have advocated the use of vitamin A or steroids.

De'Jean's Syndrome

Exophthalmos, diplopia, superior maxillary pain, and numbness along the route of the trigeminal nerve are found with lesions of the orbital floor in this syndrome.

Dejerine's Anterior Bulbar Syndrome

This syndrome is evidenced by thrombosis of the anterior spinal artery resulting in either an alternating hypoglossal hemiplegia or an alternating hypoglossal hemianesthetic hemiplegia.

8 Demarquay-Richet Syndrome

This is a congenital orofacial disorder characterized by cleft lip, cleft palate, lower lip fistulas, and progeria facies. Defective dentition, heart defects, dwarfism, and finger abnormalities may be seen.

Didmoad's Syndrome

This is an autosomal-recessive disorder associating (DI) diabetes insipidus, (DM) diabetes mellitus, (OA) optic atrophy, and (D) deafness. Diabetes mellitus is usually juvenile in onset and is insulin-dependent. The diabetes insipidus has a varied time of onset and is vasopressin-sensitive indicative of degeneration of the hypothalamic cells or of the supraoptico-hypophyseal tract. The hearing loss is sensorineural, progressive, and primarily affects the higher tones. Urinary tact abnormalities ranging from atonic bladder to hydronephrosis and hydroureter have been reported with this disorder.

DiGeorge's Syndrome

Lischaneri reported three categories of this syndrome:

1. Third and fourth pharyngeal pouch syndrome which is characterized by cardiovascular and craniofacial anomalies as well as abdominal visceral abnormalities.

2. DiGeorge syndrome (thymus agenesis).

3. Partial DiGeorge syndrome (thymic hypoplasia in which the thymus gland weighs less than 2 g).

The patients have small malformed pinnae with narrow external auditory canals and abnormal ossicles. The patients also have shortened cochlea of the Mundini type as well as absence of hair cells in the hook region, hypertelorism with nasal cleft, shortened philtrum, and micrognathia. Other middle ear anomalies include absence of stapedial muscle, hypoplastic facial nerve, and absent oval window. Most of the findings are symmetrical.

Down's Syndrome (see Trisomy in Chap. 9)

Dysphagia Lusoria

This dysphagia is secondary to an abnormal right subclavian artery. The right subclavian arises abnormally from the thoracic aorta by passing behind or in front of the esophagus, thus compressing it.

Eagle's Syndrome

The patient has elongation of the styloid process or ossification o fthe stylohyoid ligament causing irritation of the trigeminal, facial, glossopharyngeal, and vagus nerves. Symptoms include recurrent nonspecific throat discomfort, foreign body sensation, dysphagia,

9 facial pain, and increased salivation. Carotidynia may result from impingement of the styloid process on the carotid artery, producing regional tenderness or headaches.

Ectodermal Dysplasia, Hydrotic (see Chap. 9)

Ectodermal Dysplasia, Hypohidrotic

This syndrome consists of hypodontia, hypotrichosis, and hypohidrosis. Principally, the structures involved are of ectodermal derivatives. Eyelashes and especially the eyebrows are entirely missing. Eczema and asthma are common. Aplasia of the eccrine sweat glands may lead to severe hyperpyrexia. The inheritance is X-linked recessive.

18q-Syndrome

This consists of psychomotor retardation, hypotonia, short stature, microcephaly, hypoplastic midface, epicanthus, ophthalmologic abnormalities, cleft palate, congenital heart disease, abnormalities of the genitalia, tapered fingers, aural atresia and conductive hearing loss.

Eisenlohr's Syndrome

Numbness and weakness in the extremities, paralysis of the lips, tongue, palate, and dysarthria are evidenced.

Elschnig's Syndrome

Extension of the palpebral fissure laterally, displacement of the lateral canthus, ectropion of the lower lid and lateral canthus are observed. Hypertelorism, cleft palate, and cleft lip are frequently seen.

Empty Sella Syndrome

The patient has an enlarged sella, giving the appearance of a pituitary tumor. An air encephalogram shows an empty sella. The primary empty sella syndrome is due to a congenital absence of the diaphragm sella, with gradual enlargement of the sella secondary to pulsations of the brain.

The secondary empty sella syndrome may be due to necrosis of an existing pituitary tumor, after surgery, postradiation directed at the pituitary, or with pseudotumor cerebri.

Face-Hand Syndrome

This is a reflex sympathetic dystrophy that is seen after a stroke or myocardial infarction. There may be edema and erythema of the involved parts, along with persistent burning.

10 Fanconi's Anemia Syndrome

Patients have aplastic anemia with skin pigmentation, skeletal deformities, renal anomalis, and mental retardation. Death due to leukemia usually ensues within 2 years. It rarely occurs in adults. A variant of this is congenital hypoplastic thrombocytopenia which is inherited as an autosomal-recessive trait. It is characterized by spontaneous bleeding and other congenital anomalies. The bleeding time is prolonged, the platelet count is decreased, and the bone marrow megakaryocytes vary from decreased to absent.

Felty's Syndrome

Felty's syndrome is a combination of leukopenia, arthritis, and enlarged lymph nodes and spleen.

First and Second Branchial Arch Syndromes

(Hemifacial Microsomia, Lateral Facial Dysplasia)

This consists of a spectrum of craniofacial malformations characterized by asymmetric facies with unilateral abnormalities. The mandible is small with hypoplastic or absent ramus and condyle. Aural atresia, hearing impairment, tissue tags from the tragus to the oral commissure, coloboma of the upper eyelid, malar hypoplasia, and cleft palate also may be present. Cardiovascular, renal, and nervous system abnormalities have been noted in association with this disorder.

Fordyce's Disease

The disease is characterized by pseudocolloid of the lips, a condition makred by the presence of numerous, small yellowish white granules on the inner surface and vermillion border of the lips. Histologically, the lesions appear as ectopic sebaceous glands.

Foster-Kennedy Syndrome

Patients with this disorder show ipsilateral optic atrophy and scotoma and contralateral papilledema occurring with tumors or other lesions of the frontal lobe or sphenoidal meningioma. Anosmia may be seen.

Fothergill's Disease

The combination of tic douloureux and anginose scarlatina is characteristic of this disease.

Foville's Syndrome

Facial paralysis with ipsilateral paralysis of conjugate gaze and contralateral pyramidal hemiplegia are diagnostic. Tinnitus, deafness, and vertigo may occur with infranuclear involvement. Loss of taste of the anterior two-thirds of the tongue with decreased salivary and lacrimal secretions is seen with involvement of the nervus intermedius.

11 Frey's Syndrome

In the normal person, the sweat glands are innervated by sympathetic nerve fibers. After parotidectomy, the auriculotemporal nerve sends its parasympathetic fibers to innervate the sweat glands instead. The incidence of Frey's syndrome postparotidectomy in children has been estimated to be about 20$.

Inferior salivatory nucles (parasympathetic of the medulla) -->IX--> Jacobson's nerve --> otic ganglion --> auriculotemporal nerve --> parotid VII --> lesser superficial petrosal --> otic ganglion.

Friedreich's Disease

The disease consists of facial hemihypertrophy involving the eyelids, cheeks, lips, facial bones, tongue, ears, and tonsils. It may be seen alone or in association with generalized hemihypertrophy.

Garcin's Syndrome

Paralysis of cranial nerves III through X, usually unilateral or occasionally bilateral is observed. This may be the result of invasion by neoplasm, granulomas, or infections in the retropharyngeal space.

Gard-Gignoux Syndrome

This syndrome involves paralysis of the XI nerve and the X nerve below the nodose ganglion. The cricothyroid function and sensation are normal. The symptoms include vocal cord paralysis and weakness of the trapezius and sternocleidomastoid muscle.

Gardner's Syndrome

An autosomal-dominant disease, its symptoms include fibroma, osteoma of the skull, mandible, maxilla, and long bones, with epidermoid inclusion cysts in the skin and polyps in the colon. These colonic polyps have a marked tendency toward malignant degeneration.

Gargoylism (Hurler's Syndrome)

(See Chap. 9)

Gerlier's Disease

With the presence of vertigo and kubisagari, it is observed among cowherds and is a disease marked by pain in the head and neck with visual disturbances, ptosis, and generalized weakness of the muscles.

12 Gilles de la Tourette's Syndrome

Characterized by chorea, coprolalia, and tics of the face and extremities, it affects children (usually boys between 5-10 years old). Repetitive facial grimacing, blepharospasms, and arm and leg contractions may be present. Compulsive grunting noises or hiccuping subsequently become expressions of frank obscenities.

Goldenhar's Syndrome

This is a variant of the hemifacial microsomia which is one of the more common congenital syndromes of the first and second arches. Goldenhar's syndrome manifests in varying degrees of uderdevelopment of the craniofacial structures. Major deformities involve the mandible, the ear, the orbit, and the vertebral column.

Goodwin's Tumor (Benign Lymphoepithelial Lesion)

This is characterized by inflammatory cells, lymphocytes, plasma cells, and reticular cells.

Gradenigo's Syndrome

This syndrome is due to extradural abscess involving the petrous bone. The symptoms are suppurative otitis, pain in the eye and temporal area, abducens paralysis, as well as diplopia.

Grisel's Disease

This is a nasopharyngeal disease causing nontraumatic subluxation of the atlas. This disorder usually occurs after tonsillectomy or nasal cavity inflammation. It also is known as nasopharyngeal torticollis.

Guillain-Barre Syndrome

An infectious polyneuritis of unknown etiology (? viral) causing marked paresthesias of the limbs, muscular weakness or a flaccid paralysis. CSF protein is increased without an increase in cell count.

Hallerman-Streiff Syndrome

This syndrome consists of dyscepaly, parrot nose, mandibular hypoplasia, proportionate naninsm, hypotrichosis of scalp, brows, and cilia, and bilateral congenital cataracts. The majority of patients exhibit nystagmus or strabismus. There is no demonstrable genetic basis.

Heerfordt's Syndrome or Disease

It gives uveoparotid fever and is a form of sarcoidosis (see Chap. 30).

13 Hick's Syndrome

A rare condition characterized by a sensory disorder of the lower extremities resulting in perforating foot ulcers associated with progressive deafness due to atrophy of the cochlear and vestibular ganglia.

Hippel-Lindau Disease

Angioma of the cerebellum, usually cystic, associated with angioma of the retina and polycystic kidneys.

Hollander's Syndrome

With this syndrome there is appearance of a goiter in the third decade of life related to a partial defect in the coupling mechanism in thyroxine biosynthesis. Deafness due to cochlear abnormalities is usually related.

Homocystinuria

This is a recessive hereditary syndrome secondary to a defect in methionine metabolism with resultant homocystinemia, mental retardation, and sensorineural hearing loss.

Horner's Syndrome

The presenting symptoms are ptosis, miosis, anhidrosis, and enophthalmos due to paralysis of the cervical sympathetic nerves.

Horton's Neuralgia

Patients have unilateral headaches centered behind or close to the eye accompanied by or preceded by ipsilateral nasal congestion, suffusion of the eye, increased lacrimation, and facial redness and swelling.

Hunt's Syndrome

1. Cerebellar tumor, an intention tremor that begins in one extremity gradually increasing in intensity and subsequently involving other parts of the body.

2. Facial paralysis, otalgia and aural herpes due to disease of both motor and sensory fibers of the VII nerve.

3. A form of juvenile paralysis agitans associated with primary atrophy of the pallidal system.

Immotile Cylia Syndrome

This appears to be a congenital defect in the ultrastructure of cilia that renders them incapable of movement. Both the respiratory tract cilia and the sperm are involved. The

14 clinical picture includes bronchiectasis, sinusitis, male sterility, situs inversus, and otitis media. Histologically, there is a complete or partial absence of dynein arms which are believed to be essential for cilia movement and sperm tail movement. Also no cilia movements were observed in the mucosa of the middle ear and the nasopharynx.

Inversed Jaw Winking Syndrome

When there are supranuclear lesions of the V nerve, touching the cornea may produce a brisk movement of the mandible to the opposite side.

Jackson's Syndrome

Cranial nerves X, XI, and XII are affected by a nuclear or radicular lesion. There is ipsilateral flaccid paralysis of the soft palate, pharynx, and larynx with weakness and atrophy of the stenocleidomastoid and trapezius muscles and muscles of the tongue.

Jacod's Syndrome

This syndrome consists of total ophthalmoplegia, optic tract lesions with unilateral amaurosis, and trigeminal neuralgia. It is caused by a middle cranial fossa tumor involving the second through sixth cranial nerves.

Job's Syndrome

This is one of the group of hyper-IgE syndromes, which are associated with defective chemotaxis. The clinical picture includes fair skin, red hair, recurrent staphylococcal skin abscesses with concurrent other bacterial infections and skin lesions, as well as chronic purulent pulmonary infections and infected eczematoid skin lesions. This syndrome obtained its name from the Biblical passage referring to Job's being smitten with boils by Satan. It is of interest to the otolaryngologist becasue of head and neck infections.

Vernet's Syndrome

Cranial nerves IX, X, and XI are paralyzed while XII is spared because of its separate hypoglossal canal. Horner's sydrome is not present since the sympathetic chain is below the foramen. This syndrome is most often caused by lymphadenopathy of the nodes of Krause in the foramen. Thrombophlebitis, tumors the jugular bulb, and basal skull fracture can cause the syndrome. The glomus jugulare usually gives a hazy margin of involvement while neurinoma gives a smooth, sclerotic margin of enlargement. The jugular foramen is bound medially by the occipital bone and laterally by the temporal bone. The foramen is divided into anteromedial (pars nervosa) and posterolateral (pars vascularis) areas by a fibrous or bony septum. The medial area transmits nerves IX, X, and XI as well as the inferior petrosal sinus. The posterior compartment transmits the internal jugular vein and the posterior meningeal artery. The right foramen is usually slightly larger than the left foramen.

15 Kallman's Syndrome

This consists of congenital hypogonadotrophic eunuchoidism with anosma. It is transmitted via a dominant gene with variable penetrance.

Kaposi's Sarcoma

Patients have multiple idiopathic, hemorrhagic sarcomatosis particularly of the skin and viscera. Radiotherapy is the treatment of choice.

Kartagener's Syndrome

The symptoms are complete situs inversus associated with chronic sinusitis and bronchiectasis. This also is called Kartagener's triad.

Keratosis Palmaris or Solaris

This is an unusual inherited malformation. If these people live to 65 years old 50-75% of them would have developed carcinoma of the esophagus.

Kleinschmidt's Syndrome

Symptoms include influenzal infections resulting in laryngeal stenosis, suppurative pericarditis, pleuropneumonia, and occasionally meningitis.

Klinefelter's Syndrome

This is a sex chromosome defect characterized by eunuchoidism, azoospermia, gynecomastia, mental deficiency, small testes with atrophy and hyalinization of seminiferous tubules. The karyotype is usually XXY.

Klinkert's Syndrome

Paralysis of the recurrent and phrenic nerves due to a neoplastic process in the root of the neck or upper mediastinum is evidenced. The sympathetics may be involved. The left side involvement is more common than right side involvement. This can be a part of Pancoast's syndrome.

Larsen's Syndrome

Larsen's syndrome is characterized by widely spaced eyes, prominent forehead, flat nasal bridge, midline cleft of the secondary palate, bilateral dislocation of the knees and the elbows, deformities of the hands and feet, spatula-type thumbs, sometimes with tracheomalacia, stridor, laryngomalacia, and respiratory difficulty. Therapy includes maintaining adequate ventilation.

16 Lermoyez's Syndrome

This is a variant of Ménière's disease. It was first described by Lermoyez in 1921 as deafness and tinnitus followed by a vertiginous attack which relieved the tinnitus and improved the hearing.

Loeffler's Syndrome

This consists of pneumonitis characterized by eosinophiles in the tissues. This is possibly of parasitic etiology.

Louis-Bar Syndrome

This autosomal recessive disease presents as ataxia, oculocutaneous telangiectasia, and sinopulmonary infection. It involves progressive truncal ataxia, slurred speech, fixation nystagmus, mental deficiency, cerebellar atrophy, deficient immunoglobulin and marked frequency of lymphoreticular malignancies. The patient rarely lives past 20 years of age.

Maffucci's Syndrome

This is characterized by multiple cutaneous hemangiomas with dyschondroplasia and often enchondroma. The origin is unknown and it is not hereditary. Signs and symptoms of this syndrome usually appear early in life during infancy. It equally affects both sexes and has no racial preference. The dyschondroplasia may cause sharp bowing or an uneven growth of the extremities as well as giving rise to frequent fractures. Five to ten percent of Maffucci's syndrome patients have head and neck involvement giving rise to cranial nerve dysfunction and hemangiomas in the head and neck area. The hemangiomas in the nasopharynx and larynx could cause airway compromise as well as deglutition problems. Fifteen to twenty percent of these patients later undergo sarcomatous degeneration in one or more of the enchondromas. The malignant changes are greater in the older patients. The percentage of malignant degeneration approaches 44% in patients over 40 years old.

Markus-Gunn Syndrome (Jaw Winking Syndrome)

There is increase in width of the eyelids during chewing. Sometimes the patient experiences rhythmic elevation of the upper eyelid when the mouth is open and ptosis when the mouth is closed.

Marie-Strumpell Disease

This is rheumatoid arthritis of the spine.

Melkersson-Rosenthal Syndrome

A congenital disease of unknown etiology, it manifests as recurring attacks of unilateral or bilateral facial paralysis (see Chap. 10), swelling of the lips, and furrowing of the tongue.

17 Middle Lobe Syndrome

This is a chronic atelectatic process with fibrosis in one or both segments of the middle lobe. It is usually secondary to obstruction of the middle lobe bronchus by hilar adenopathy. The hilar adenopthy my be transient but the bronchiectasis that resulted persists. Treatment is by surgical resection.

Mikulicz's Disease

The symptoms characteristic of Mikulicz's disease (swelling of lacrimal and salivary gland) occurs as a complication of some other disease such as lymphocytosis, leukemia, or uveoparotid fever (see Chap. 17).

Millard-Gubler Syndrome

Patients present with ipsilateral paralysis of the abducens and facial nerves with contralateral hemiplegia of the extremities. This is due to obstruction of the vascular supply to the pons.

Möbius Syndrome

This is a congenital facial diplegia (usually bilateral), with unilateral or bilateral loss of the abductors of the eye, anomalies of the extremities, aplasia of the brachial and thoracic muscles, and frequently involves other cranial nerves. The etiology could be a primary muscle defect or neurogenic in nature. Saito showed evidence that the site of nerve lesions is in the peripheral nerve.

Morgagni-Stewart-Morel Syndrome

It occurs in menopausal women and is characterized by obesity, dizziness, psychological disturbances, inverted sleep rhythm, and hyperostosis frontalis interna. Treatment is supportive.

Multiple Endocrine Adenomatosis

MEA type IIA Sipple's Syndrome

A familial syndrome consisting of medullary carcinoma of the thyroid, hyperparthyroidism, and pheochromocytoma.

MEA Type IIB

This variant consists of multiple mucosal neuromas, pheochromocytoma, medullary carcinoma of the thyroid, and hyperprathyroidism. This syndrome is inherited in an autosomal-dominant pattern. Mucosal neuromas principally involve the lips and anterior tongue. Numerous white medullated nerve fibers traverse the cornea to anastomose in the pupillary area.

18 Munchausen's Syndrome

This syndrome was named after Baron Hieronymus Carl Friedrich von Munchausen (1720-1791) by Asher in 1951. The integral features of this syndrome are:

1. A real organic lesion from the past which has left some genuine signs but is causing no organic symptoms.

2. Exorbitant lying with dramatic presentation of nonexistent symptoms.

3. Travelling widely with multiple hospitalizations.

4. These patients have criminal tendencies.

These patients usually go from medical center to medical center to be admitted with dramatic presentation of nonorganic symptoms related to a real organic lesion on the past medical history.

Myenburg's Syndrome (Familial Myositis Fibrosa Progressiva)

This is a disease in which the striated muscles are replaced by fibrosis. Fibrosarcoma rarly originates from this disease.

Nager's Syndrome

Acrofacial dysostosis patients have facies similar to Treacher Collins syndrome. They also present with preaxial upper limb defects, microtia, atresia of the external auditory canal, and malformation of the ossicles. Both conductive and mixed hearing losses may occur.

Nager-de Reynier Syndrome

Hypoplasia of the mandible with abnormal implantation of teeth associated with aural atresia characterize this syndrome.

Neurofibromatosis (von Recklinghausen's Disease)

Salient features:

1. Autosomal dominant. 2. Mental retardation common in families with neurofibromatosis. 3. Arises from neurilemmal cells or sheath of Schwann and fibroblasts of peripheral nerves. 4. Cafe-au-lait spots - giant melanosomes. The presence of six or more spots greater than 1.5 cm is diagnostic of neurofibromatosis even if the family history is negative. 5. Of all neurofibromatosis 4-5% undergo malignant degeneration with sudden increase of growth of formerly static nodules. These may become neurofibrosarcomas. They may metastasize widely.

19 External features:

1. Cafe-au-lait spots. 2. Fibromas.

Internal features:

1. Pheochromocytoma. 2. Meningioma. 3. Acoustic neurinoma: often bilateral. 4. GI bleeding. 5. Intussusception bowel. 6. Hypoglycemia (intraperitoneal fibromas). 7. Fibrous dysplasia. 8. Subperiosteal bone cysts. 9. The optic nerve may be involved causing blindness and proptosis. 10. May present with macroglossia. 11. May involve the parotid or submaxillary gland. 12. The nodules may be painful. 13. Nodules may enlarge suddenly if bleeding of the tumor occurs or if there is malignant degeneration.

The treatment of this disease is only to relieve pressure from expanding masses. It usually does not recur if the tumor is completely removed locally.

Nothnagel's Syndrome

The symptoms include dizziness, a staggering and rolling gait, with irregular forms of oculomotor paralysis. Nystagmus often is present. This syndrome is seen in cases of tumor of the midbrain.

Oculopharyngeal Syndrome

It is characterized by hereditary ptosis and dysphagia, an autosomal-dominant disease with equal incidence in both sexes. It is related to a high incidence of esophageal carcinoma. Its age of onset is between 40-50 years old and is particularly common among the French Canadians. Marked weakness of the upper esophagus is observed together with an increase in serum creatinine phosphokinase. It is a myopathy and not neuropathy. Treatment includes dilatation and cricopharyngomyotomy.

Odine's Curse

Failure of respiratory center automaticity with apnea especially evident during sleep is symptomatic. It is also known s the alveolar hypoventilation syndrome. This may be associated with increased appetite and transient central diabetes insipidus. Hypothalamic lesions are thought to be the cause of this disorder.

20 Ollier's Disease

This consists of multiple chondromatosis, 10% of which is associated with chondrosarcoma.

Oral-Facial-Digital Syndrome I (see Ch. 9 for oral-facial-digital syndrome II)

A lethal train in males, it is inherited as an X-linked dominant trait limited to females. Symptoms include multiple hyperplastic frenula, cleft tongue, dystopia canthorum, hypoplasia of the nasal alar cartilages, median cleft of the upper lip, asymmetric cleft palate, digital malformation and mild mental retardation. About 50% of the patients have hamartoma between the lobes of the divided tongue. This mass consists of fibrous connective tissue, salivary gland tissue, few striated muscle fibers, and rarely cartilage. One-third of the patients present with ankyloglossia.

Orbital Apex Syndrome

This involves the nerves and vessels pathing through the superior sphenoid fissure and the optic foramen with paresis of cranial nerves III, IV, and VI. External ophthalmoplegia is associated with internal ophthalmoplegia with a dilated pupil which does not react to either light or convergence. Ptosis as well as periorbital edema are due to the IV nerve paresis. Sensory changes are secondary to the lacrimal frontal nasal ciliary nerves as well as the three branches of the ophthalmic nerve. The optic nerve usually is involved.

Ortner's Syndrome

Cardiomegaly associated with laryngeal paralysis secondary to compression of the recurrent laryngeal nerve is observed.

Osler-Weber-Rendu Disease

Hereditary Hemorrhagic Telangiectasia

It is an autosomal-dominant disease in which the heterozygote lives to adult life while the homozygous state is lethal at an early age. The patient has punctate hemangioma (elevated, dilated, capillaries and venules) in the mucous membrane of the lips, tongue, mouth, gastrointestinal tract, etc. Pathologically, these are vascular sinuses of irregular size and shape lined by a thin layer of endothelium. The muscular and elastic coats are absent. Because of their thin walls these vascular sinuses bleed easily and because of the lack of muscular coats, this bleeding is difficult to control. The patient has normal blood elements and no coagulation defect. The other blood vessels are normal as well. If a person with this disease marries a normal person, what are the chanes that the offspring will have this condition? Since the patient with this disease is an adult, we can assume that he is heterozygous since the homozygote dies early in life. Therefore, the child will have a 50% chance of having this hereditary disease.

21 Paget's Disease (Osteitis Deformans) (See Chap. 9)

This term also is used to characterize a disease of elderly women with an infiltrated, eczematous lesion surrounding the nipple and areola associataed with subjacent intraductal carcinoma of the breast.

Paget's Osteitis

This is related to sarcomas.

Pancoast's Syndrome (See Chap. 28)

Peutz-Jeghers' Syndrome

The patient has pigmentation of the lips, oral mucosa, and benign polyps of the gastrointestinal tract. Granulosa theca cell tumors have been reported in females with this syndrome.

Pheochromocytoma

Pheochromocytoma is asssociated with neurofibromatosis, cerebellar hemangioblastoma, ependymoma, astrocytoma, meningioma, spongioblastoma, multiple endocrine adenoma, or with medullary carcinoma of the thyroid. Pheochromocytoma with or without the above tumors may be inherited as an autosomal-dominant trait. Some patients have megacolon, other suffer neurofibromatosis of Auerbach's and Meissner's plexuses.

Pierre-Robin Syndrome

This consists of glossoptosis, micrognathia, and cleft palate. There is no sex predilection. The etiology is believed to be intrauterine insult at the fourth month of gestation or perhaps hereditary. Two-thirds of the cases are associated with ophthalmologic difficulties (i.e. detached retina or glaucoma), one-third are associated with otologic problems (i.e. chronic otitis media and low-set ears). Mental retardation is present occasionally. If the patient lives past 5 years old, he can lead a fairly normal life (see Chap. 9). The symptoms aare choking and aspiration as a result of negative pressure created by excessive inspiratory effort. Passing of a NA tube may alleviate the negative pressure. Aerophagia has to be treated to prevent vomiting, airway compromise, and aspiration. Tracheotomy may not be the answer.

Plummer-Vinson Syndrome (Patterson-Kelly Syndrome)

Symptoms include dysphagia due to degeneration of the esophageal muscle, atrophy of the papillae of the tongue, as well as microcytic hypochromic anemia. Achlorhydria, glossitis, pharyngitis, esophagitis, and fissures at the corner of the mouth also are observed. The prevalence of this disease is higher in females than in males, and usually presents in patients who are in their fourth decade. Treatment consists of iron administration, with esophagoscopy for dilatation and to rule out carcinoma of the esophagus, particularly at the postcricoid region. Pharyngoesophageal webs or stenosing may be noted.

22 This disease is to be contrasted with pernicious anemia which is a megaloblastic anemia with diarrhea, nausea and vomiting, neurologic symptoms, enlarged spleen, and achlohydria. Pernicious anemia is secondary to failure of the gastric fundus to secrete intrinsic factors necessary for vitamin B12 absorption. Treatment consists of IM B12 (riboflavin).

Folic acid deficiency also gives rise to megaloblastic anemia, cheilosis, glossitis, ulcerative stomatitis, pharyngitis, esophagitis, dysphagia, and diarrhea. No neurologic symptoms and no achlorhydria are present. Treatment is through administration of folic acid.

Pyknodysostosis

This is a syndrome consisting of dwarfism, osteopetrosis, partial agenesis of the terminal phalanges of the hands and feet, cranial anomalies (persistent fontanels), frontal and occipital bossing and hypoplasia of the angle of the mandible. The facial bones are usually underdeveloped with pseudoprognathism. The frontal sinuses are consistently absent and the other paranasal sinuses are hypoplastic. The mastoid air cells often are not pneumatized. Toulouse-Lautrec probably had this disease.

Reichert's Syndrome

Neuralgia of the glossopharyngeal nerve, usually precipitated by movements of the tongue or throat.

Reiter's Syndrome

Arthritis, urethritis, conjunctivitis.

Riedel's Struma

This is a form of thyroiditis seen most frequently in middle-aged females manifested by compression of surrounding sturctures (i.e. trachea). There is loss of the normal thyroig lobular architecture and replacement with collagen and lymphocyte infiltration.

Rivalta's Disease

This is an actinomycotic infection characterized by multiple indurated abscesses of the face, neck, chest, and abdomen that discharge through numerous sinus tracts.

Rollet's Syndrome (Orbital Apex - Sphenoidal Syndrome)

It is caused by lesions of the orbital apex which cause paralysis of cranial nerves III, IV, and VI. This syndrome is characterized by ptosis, dyplopia, ophthalmoplegia, optic atrophy, hyperesthesia or anesthesia of the foreheadm, upper eyelid, and cornea, and retrobulbar neuralgia. Exophthalmos and papilledema my occur.

23 Romberg's Syndrome

Progressive atrophy of tissues on one side of the face occasionally extending to other parts of the body, that may involve the tongue, gums, soft palate, cartilages of the ear, nose, and larynx. Pigmentation disorders, trigeminal neuralgia, and ocular complications may be seen.

Rutherford's Syndrome

A familial oculodental syndrome characterized by corneal dystrophy, gingival hyperplasia, and failure of tooth eruption.

Scalenus Anticus Syndrome

The symptoms are identical to those of cervical rib syndrome. In scalenus anticus syndrome, symptoms are causd by comprssion of the brachial plexus and subclavian artery against the first thoracic rib, probably as the result of spasms of the scalenus anticus muscle bringing pressure on the brachial plexus and the subclavian artery. Any pressure on the sympathetic nerves may caus vascular spasm resembling Raynaud's disease.

Schafer's Syndrome

Hereditary mental retardation, sensorineural hearing loss, prolinemia, hematuria, and photogenic epilepsy are characteristic. This syndrome is due to a deficiency of proline oxidase with resultant build up of the amino acid proline.

Schaumann's Syndrome

This is generalized sarcoidosis (see Chap. 30).

Schmidt's Syndrome

Unilateral paralysis of a vocal cord, of the velum palati, of the trapezius, and of the sternocleidomastoid muscles is found. The lesion is locted in the caudal portion of the medulla and is usually of vascular origin.

Seckel's Syndrome

A disorder which consists of dwarfism associated with a bird-like facies, beaked nose, micrognathia, palate abnormalities, low-set lobeless ears, antimongoloid slnt of the palpebral fissures, clinodactyly, mental retardation, and bone disorders.

Sheehan's Syndrome

Ischemic necrosis of the anterior pituitary associated with postpartum hypotension characterize this syndrome.

24 Sjögren's Syndrome (Sicca Syndrome)

Manifesting as keratoconjunctivitis sicca, dryness of the mucous membranes, telangiectasias or purpuric spots on the face, and bilateral parotid enlargement, this syndrome is often seen in menopausal women associated with rheumatoid arthritis, Raynaud's phenomenon, and dental caries. Changes in the lacrimal and salivary glands resemble those of Mikulicz's disease. Some attribute this syndrome to vitamin A deficiency. A positive LE preparation, rheumatoid factor, and an abnormal protein can be identified in this disorder.

Sleep Apnea Syndrome

The definition of apnea is a "cessation of airflow greater than 10 seconds in duration". Sleep apnea syndrome is said to occur when at least 30 episodes of apnea occur within a 7- hour period. Another definition of sleep apnea syndrome is when 1% of the sleeping time is spent in apnea. The cause of sleep apnea is unclear. Some people believe it is of central origin; others think that it may be aggravated by hypertrophied and occluding tonsils and adenoids. Some investigators classify sleep apnea into central apnea, upper airway apnea, and mixed apnea. Monitoring of the EEG and other brain stem evoked response measurements may help to identify central apnea.

Sluder's Neuralgia

The symptoms are neuralgia of the lower half of the face, nasal congestion, and rhinorrhea associated with lesions of the sphenopalatine ganglion. Ocular hyperemia and increased lacrimation may be seen.

Stevens-Johnson Syndrome

This is a skin disease (erythema multiforme) with involvement of the oral cavity (stomatitis) and the eye (conjunctivitis). Stomatitis may appear as the first symptom. It is most common in the third decade of life. Treatment is largely with steroid and supportive therapy. This is a self-limiting disease, but has a 25% recurrence rate. The differential diagnosis would include (1) herpes simplex, (2) pemphigus, (3) acute fusospirochetal stomatitis, (4) chickenpox, (5) monilial infection, and (6) secondary syphilis.

Still's Disease

Rheumatoid arthritis in children is sometimes called Still's disease (see pediatric textbook for more details).

Sturge-Weber-Syndrome

This is a congenital disorder which affects both sexes equally, and is of unknown etiology. It is characterized by venous angiom of the leptomeninges over the cerebral cortex, ipsilateral port-wine nevi, and frequent angiomatous involvement of the globe, mouth, and nasal mucosa. The patient may have convulsions, hemiparesis, glaucoma, and intracranial calcifications. There is no specific treatment.

25 Subclavian Steal Syndrome

Stenosis or occlusion of the subclavian or innominate artery proximal to the origin of the vertebral artery causes the pressure in the vertebral artery to be less than that of the basilar artery, particularly when the upper extremity is in action. Hence, the brain receives less blood and may be ischemic. The symptoms consist of intermittent vertigo, occipital headache, blurred vision, diplopia, dysarthria, and pain in the upper extremity. The diagnosis, made through the patient's medical history, can be confirmed by the differencee in blood pressure in the two upper extremities, by a bruit over the supraclavicular fossa, and by angiography.

Superior Orbital Fissure Syndrome

Orbital Apex Syndrome; Optic Foramen Syndrome, Sphenoid Fissure Syndrome

There is involvement of cranial nerves III, IV, VI, V1, the ophthalmic veins, and sympathetics of the cavernous sinus. This syndrome can be caused by sphenoid sinusitis or by any neoplasia in that region. Symptoms include paralysis of the upper lid, orbitl pain, photophobia, and paralysis of the above nervs. The optic nerve may be damaged as well.

Superior Vena Cava Syndrome

This is obstruction of the superior vena cava or its main tributaries by bronchogenic carcinoma, mediastinal neoplasm, or lymphoma. Rarely, the presencee of a substernal goiter causes edeema and engorgement of the vessels of the face, neck, and arms, as well as a nonproductive cough and dyspnea.

Tapia's Syndrome

Unilateral paralysis of the larynx and tongue is coupled with atrophy of the tongue while the soft palate and cricothyroid muscle are intact. This syndrome is usually caused by a lesion at the point where XII and X nerves together with the internal carotid artery cross one another.

Tay-Sachs Disease

An infantile form of amaurotic familial idiocy with strong familial tendencies, it is of questionably recessive inheritance. It is more commonly found among those of Semitic extraction. Histologically, the nerve cells are distorted and filled with a lipid material. The juvenilee form of this is called Spielmeyer-Vogt's disease in which the patient is normal until after 5-7 years of age. This juvenile form is seen in children of non-Semitic extraction as well.

Tietze's Syndrome

A costal chondritis, chondropathia tuberosa, of unknown etiology, its symptoms include pain, tenderness, and swelling of one or more of the upper costal cartilages (usually of the second rib). Tretament is symptomatic.

26 Tolosa-Hunt Syndrome

A cranial polyneuropathy usually presenting as recurrent unilateral painful ophthalmoplegia. Cranial nerves II, III, IV, V1 and VI may be involved. The etiology is unknown and there is a tendency for spontaneous resolution and for recurrence. An orbital venogram may show occlusion of the superior ophthalmic vein and at least partial obliteration of the cavernous sinus. The clinical course often responds well to systemic steroids.

Treacher-Collins Syndrome (See Chap. 9)

Trotter's Syndrome (Sinus of Morgagni Syndrome)

Neuralgia of the inferior maxillary nerve, conductive hearing loss secondary to eustachian tube blockage, preauricular edema caused by neoplastic invasion of the sinus of Morgagni, ipsilateral akinesia of the soft palate, and trismus are observed in this syndrome.

Tube-Feeding Syndrome (See Chap. 37, 65)

Turner's Syndrome (See Chap. 9)

Turpin's Syndrome

Patients have congenital bronchiectasis, megaesophagus, tracheoesophageal fistula, vertebral deformities, rib malformations and heterotopic thoracic duct.

Vail's Syndrome

This syndrome consists of unilateral, usually nocturnal, vidian neuralgia which may be associated with sinusitis.

Vernet's Syndrome

See Jugular Foramen Syndrome.

Villaret's Syndrome

This is the same as the jugular foramen syndrome except that Horner's syndrome is present here, suggesting more extensive involvement in the region of the jugular foramen, the retroparotid area, and the lateral pharyngeal space.

Vogt-Koyanagi-Harada Syndrome

Spastic diplegia with athetosis and pseudobulbar paralysis associated with a lesion of the caudate nucleus and putamen, bilateral uveitis, vitiligo, deafness, alopecia, increased CSF pressure, and retinal detachment are evidenced.

27 Wallenberg's Syndrome

Also called syndrome of the posterior inferior cerebellar artery thrombosis or lateral meduallary syndrome, this syndrome is due to thrombosis of the posteroinferior cerebellar artery giving rise to ischemia of the brain stem (lateral medullary region). Symptoms include vertigo, nystagmus, nausea, vomiting, Horner's syndrome, dysphagia, dysphonia, hypotonia, asthenia, ataxia, falling to the side of the lesion and loss of pain and temperature sense on the ipsilateral face and contralateral side below the neck.

Weber's Syndrome

This is characterized by paralysis of the oculomotor nerve on the side of the lesion and paralysis of the extremities, face, and tongue on the contralateral side. It indicates a lesion in the ventral and internal part of the cerebral peduncle.

Wilson's Disease (Hepatolenticular Degeneration)

There are two chief types: one rapidly progressive which occurs in late childhood, the other slowly progressive occurring in the third of fourth decades. Familial, its symptoms are cirrhosis with progressive damage to the nervous system, brown pigmentation of the outer margins of the cornea called Kayser-Fleischer ring, and it can present with hearing loss as well.

Winkler's Disease (Chondrodermatitis Nodularis Chronica Helicis)

Arteriovenous anastomosis and nerve endings accumulation at the helical portion of the ear are evident. It presents with pain and is characterized by hard, round nodules involving the skin and cartilage of the helix. Ninety percent occurs in males. The treatment is to excise it or treat it with steroids.

Xeroderma Pigmentosum (Autosomal Recessive)

This presents with photosensitive skin with multiple basal cell epitheliomas. Squamous cell carcinoma or malignant melanoma can result from it. This condition occurs mainly in children. These children should be kept away from the sun.

Eponyms

Adenoid Facies: Crowded teeth, high-arched palate, under-developed nostrils.

Adler Bodies: Deposits of mucopolysaccharide found in neutrophils of the patients with Hurler's syndrome.

Antoni's Type A and Type B: See Chap. 37.

Arnold-Chiari Malformation:

28 Type I: Downward protrusion of the long, thin, cerebellar tonsils through the foramen magnum.

Type II: Protrusion of the inferior cerebellar vermis through the foramen.

Type III: Bony occipital defect with descent of the entire cerebellum.

Type IV: Cerebellar hypoplasia.

Abrikossoff's Tumor (granular cell myoblastoma): Causes pseudoepithelial hyperplasia in the larynx, the site most favored in the larynx being the posterior half of the vocal cord. Three percent of granular cell myoblastoma progresses to malignancy. In order of decreasing frequency of involvement, the granular cell myoblastoma occurs in tongue, skin, breast, subcutaneous tissue, and respiratory tract.

Arnold's Ganglion: Otic ganglion.

Aschoff Body: Rheumatic nodule found in rheumatic disease.

Ballet's Sign: Paralysis of voluntary movement of the eyeball with preservation of the automatic movements. Sometimes this sign is present in exophthalmic goiter and hysteria.

Bechterew's Symptom: Paralysis of facial muscles limited to automatic movements. The power of voluntary movement is retained.

Bednar's Aphtae: Symmetrical excoriations of the hard palate in the region of the pterygoid plates, due to sucking of the thumb or foreign object or to scalding.

Bezold's Abscess: Abscess in the sternocleidomastoid muscle secondary to perforation of the tip of the mastoid by infection.

Blandin, Gland of: A minor salivary gland situated in the anterior portion of the tongue.

Brooke's Tumor (epithelioma adenoid cystica): This originates from the hair follicles in the external auditory canal and auricle. It is of basal cell origin. Treatment is through local resection.

Broyle's Ligament: Anterior commissure ligament of the larynx.

Brudzinski's Sign: In meningitis, a passive flexion of the leg on one side causes a similar movement to occur in the opposite leg. Passive flexion of the neck brings about a flexion of the legs as well.

"Brunner's" Abscess: Abscess of the posterior floor of the mouth.

Brun's Sign: Intermittent headache, vertigo, and vomiting, especially with sudden movements of the head. This occurs in cases of tumor of the fourth ventricle of the brain.

29 Bryce's Sign: A gurgling is heard in a neck mass. It suggests a laryngocele.

Carhart's Notch: Maximum dip at 2000 kHz (bone conduction) seen in patients with otosclerosis.

Charcot-Leyden Crystals: Crystals in the shape of elongated double pyramids, composed of spermine phosphates and present in the sputum of asthmatic patients. Synonyms are: Charcot-Newman crystals, Charcot-Robin crystals.

Charcot's Triad: The nystagmus, scanning speech, and intention tremor seen in multiple sclerosis.

Cherubism: Familial, with the age of predilection between 2-5 years old. It is characterized by giant cell reparative granuloma causing cystic lesions in the posterior rami of the mandible. The lesions are usually symmetric. It is a self-limiting disease with remissions after puberty. The maxilla also may be involved.

Chvostek's Sign: It is the facial twitch obtained by tapping the distribution of the facial nerve. It is indicative of hypocalcemia and is the most reliable test for hypocalcemia.

Curschmann's Spirale: Spirally twisted masses of mucus present in the sputum of bronchial asthmatic patients.

Demarquay's Sign: Absence of elevation of the larynx during deglutition. This is said to indicate syphilitic induration of the trachea.

di Sant' Agnese Test: It measures the elevated sodium and chloride in the sweat of cystic fibrotic children.

Dupre's Sign: Meningism.

Ebner, Gustatory Glands of: These are the minor salivary glands near the circumvallate papillae.

Escherich's Sign: In hypoparathyroidism, tapping of the skin at the angle of the mouth causes protrusion of the lips.

Galen's Anastomosis: An anastomosis between the superior laryngeal nerve and the recurrent laryngeal nerve.

Goodwin's Tumor: Benign lymphoepithelioma. (See Chap. 17)

Griesinger's Sign: Edema of the tip of the mastoid in thrombosis of the sigmoid sinus.

Guttman's Test: In the normal subject, frontal pressure on the thyroid cartilage lowers the tone of voice produced while lateral pressure produces a higher tone of voice. The opposite is true in paralysis of the cricothyroid muscle.

30 Gyon's Sign: The twelfth nerve lies directly upon the external carotid artery, whereby this vessel may be distinguished from the internal carotid artery. The safer way prior to ligation of the external carotid artery is to identify the first few branches of the external carotid artery.

Henle, Gland of: These are the small glands situated in the areolar tissue between the buccopharyngeal fascia anteriorly and the prevertebral fascia posteriorly. Infection of these glands can lead to retropharyngeal abscess. Since these glands atrophy after the age of 5, retropharyngeal abscess is less likely to occur after that age.

Hennebert's Sign: (See Chap. 9, Congenital Deafness) The presence of a positive fistula test in the absence of an obvious fistula is called Hennebert's sign. The patient has a normal appearing tympanic membrane and external auditory canal. The nystagmus is more marked upon application of a negative pressure. This sign is present in congenital syphilis and is believed to be due to an excessively mobile footplate or caused by motion of the saccule mediated by fibrosis between the footplate and the saccule.

Hering-Breuer Reflex: Respiratory reflexes from pulmonary stretch receptors. Inflation of the lungs sends an inhibitory impulse to the central nervous system via the vagus nerve to stop inspiration. Similarly, a deflation of the lungs sends an impulse to stop expiration.

Kernig's Sign: When the subject lies on his back, with the thigh at a right angle to the trunk, straightening of the leg (extending the leg) will elicit pain, supposedly due to the pull on the inflamed lumbosacral nerve roots. This sign is present in meningitis.

Kiesselbach's Plexus: This is an area in the anterior septum where the capillaries merge. It is often the site of anterior epistaxis. It also has been referred to as the Little's region.

Koplik's Spots: Pale round spots on the oral mucosa, conjunctiva, and lacrimal caruncle, seen in the beginning stages of measles.

Krause's Nodes: These are the nodes in the jugular foramen.

Lhermitte's Sign: Patients develop sensory deficits and complain of "electric shocks" radiating down the back and into the extremities after neck flexion. This occurs 2-4 months after completion of radiation therapy to the CNS or spinal canal and is classified as an early transient myelopathy.

Lillie-Crowe Test: Used in the diagnosis of unilateral sinus thrombophlebitis. Digital compression of the opposite internal jugular vein causes the retinal vessels to dilate.

Little's Area: See Kiesselbach's Plexus.

Ludwig's Angina: See Chap. 16.

Luschka's Pouch: See Thornwaldt's Disease.

31 Marcus Gunn's Phenomenon: Unilateral ptosis of the eyelid with exaggerated opening of the eye during movements of the mandible.

Marjolin's Ulcer: This is a carcinoma that arises at the site of an old burn scar. It is a well differentiated squamous cell carcinoma, aggressive, and metastasizes rapidly.

Meckel's Ganglion: Sphenopalatine ganglion.

Mikulicz's Cells: These are macrophages in rhinoscleroma. Russel bodies which are eosinophilic, round structures associated with plasma cells also are found in rhinoscleroma.

Mollaret-Debre Test: This is a test performed for cat-scratch fever.

Morgagni, Sinus of: A dehiscence of the superior constrictor muscle and the buccopharyngeal fascia where the eustachian tube opens.

Morgagni, Ventricle of: This separates the quadrangular membrane from the conus elasticus in the larynx.

Nikolsky's Sign: Detachment of the sheets of the superficial epithelial layers when any traction is applied over the surface of the epithelial involvement in pemphigus is characteristic of Nikolsky's sign. Pemphigus involves the intraepithelial layer while pemphigoid involves the subepithelial layer. The former is a lethal disease in many instances.

Oliver-Cardarelly Sign: Recession of the larynx and trachea is synchronous with cardiac systole in cases of aneurysm of the arch of the aorta, or in cases of a tumor in that region.

Parinaud's Sign: Extraocular muscle impairment with decreased upward gaze and ptosis seen in association with pinealomas and other lesions of the tectum.

Paul-Bunnel Test: It measures the elevated heterophile titer in infectious mononucleosis.

Psammoma Bodies: These are found in papillary carcinoma of the thyroid.

Rathke's Pouch: See Thorwaldt's Disease.

Reinke's Tumor: This is a "soft" tumor variant of lymphoepithelioma in which the lymphocytes predominate. In the hard tumor the epithelial cells predominate and this is called Schmincke's tumor.

Rhomberg's Sign: If a patient standing with feet together, "falls" when he closes his eyes, the Rhomberg's test is positive. It is indicative of either abnormal proprioception or abnormal vestibular function. It does not necessarily distinguish central from peripheral lesion. The cerebellar function is not tested in this test.

32 Rosenbach's Sign: Fine tremor of the closed eyelids seen in hyperthyroidism and hysteria.

Rouvier's Node: Lateral retropharyngeal node. It is a common target of metastases in nasopharyngeal carcinoma.

Russell's Bodies: Eosinophilic, round structures, associated with plasma cells found in rhinoscleroma.

Santorini's Cartilage: Corniculate cartilage of the larynx, composed of fibroelastic cartilage.

Santorini's Fissures: Fissures in the anterior bony external auditory canal leading to the parotid region.

Schaumann's Bodies: Together with asteroids, they are found in sarcoid granuloma.

Schmincke's Tumor: The "hard" variant of lymphoepithelioma in which the epithelial cells predominate (see Reinke's Tumor).

Schneiderian Mucosa: Pseudostratified ciliated columnar mucosa of the nose.

Seeligmüller's Sign: Contraction of pupil on the affected side in facial neuralgia.

Semon's Law: A law stating that injury to the recurrent laryngeal nerve results in paralysis of the abductor muscle of the larynx (cricoarytenoid posticus) before paralysis of the adductor muscles. In recovery, the adductor recovers before the abductor.

Straus' Sign: In facial paralysis, the lesion is peripheral if injection of pilocarpine is followed by sweating on the affected side later than on the normal side.

Sulkowitch's Test: It determines an increase in calciuria.

Tobey-Ayer-Queckenstedt Test: Used in the diagnosis of unilateral and bilateralsinus thrombophlebitis. In cases where the lateral sinus is obstructed on one side, compression of the jugular vein on the intact side will cause a rise in CSF pressure, whereas compression of the obstructed side does not raise the CSF pressure.

Thronwaldt's Cyst: A depression exists in the nasopharyngeal vault which is a remnant of the pouch of Luschka. When this depression becomes infected a Thornwaldt's cyst results. In the early embryo, this area has a connection between the notochord and entoderm. The Thorwaldt's cyst is lined with respiratory epithelium with some squamous metaplasia. Anterior to this pit, the path taken by Rathke's pouch sometimes persists as the craniopharyngeal canal, running from the sella turcica through the body of the sphenoid to an opening on the undersurface of the skull.

33 Toynbee's Law: When CNS complications arise in chronic otitis media, the lateral sinus and cerebellum are involved in mastoiditis while the cerebrum alone is involved in the instances of cholesteatoma of the attic.

Trousseau's Sign: In hypocalcemia, a tourniquet placed around the arm will cause tetany.

Tullio's Phenomenon: (See Chap. 9, Congenital Deafness) This is said to be present when a loud noise precipitates vertigo. It can be present in congenital syphilis with a semicircular canal fistula or in a postfenestration patient if the footplate is mobile. The tympanic membrane and ossicular chain have to be intact with mobile footplate.

Wartenberg's Sign: Intense pruritus of the tip of the nose and nostril indicates cerebral tumor.

Warthin-Finkelday Giant Cells: These are found in the lymphoid tissue in measles.

Weber's Gland: These are minor salivary glands in the superior pole of the tonsil.

Wrisberg's Cartilage: This is the cuneiform cartilage of the larynx, made of fibroelastic cartilage.

Xeroderma Pigmentosa: Hereditary precancerous condition which begins in early childhood. These patients die at puberty.

Zaufal's Sign: Saddle nose.

34 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 24: Head and Neck Radiology

Radiographic Examination of the Temporal Bone

Radiographic examination of the temporal bone consists of standard projections (Law's, Schüller's, Mayer's, Owen's, Chausse's III, Stenvers', submentovertical and Towne's), tomography, and polytomography (hypocycloidal or multidirectional), and special studies (carotid arteriography, retrograde jugular venogram, posterior fossa myelography, combined polytome and posterior fossa myelography) and, more recently, computerized tomography.

Standard Projections (Fig. 24-1, a and b)

Law's View

Law's view is a lateral view of the mastoid obtained with the sagittal plane of the skull parallel to the film and with a 15° cephalocaudal angulation of the x-ray beam. The external and internal auditory canals are superimposed. An excellent view of the cellular development and disease of the mastoid portion of the temporal bone is obtained. It also shows the tegment, the anterior wall of the lateral sinus, the external auditory canal, the temporomandibular joint, and the pneumatization of the anterior part of the squamous portion of the temporal bone. This view does not show the key area of the attic, aditus, and antrum (Fig. 24-2).

Schüller's View

Schüller's view (Runstrom) is a lateral view of the mastoid obtained with the sagittal plane of the skull parallel to the film and with a 30° cephalocaudal angulation of the x-ray beam.

This view is quite similar to the Law's view except that the x-ray tube is angled caudally 30° instead of 15°. Thus it displaces the arcuate eminence of the petrous bone downward and shows the antrum and the upper part of the attic.

It also gives an excellent view of the extent of the pneumatization of the mastoid, the distribution and the degree of aeration of the air cells, the status of the trabecular pattern, and the position of the vertical portion of the lateral sinus.

Mayer's View

Mayer's view is obtained with the head of the patient rotated 45° toward the side under examination and the tube adjusted so that the central ray passes through the external auditory meatus nearest the film at an angle of 45° toward the feet.

This gives an axial view of the petrous bone and the mastoid cells. The mastoid antrum, the external auditory meatus and the upper part of the tympanic cavity are well

1 shown. The obliquity of the Mayer's position, although necessary to free the key area from the shadow of the labyrinth, produces a distortion that may confuse the surgeon.

Owen's View

Owen's view resembles the Mayer's view but offers the advantages of less distortion. The patient's head is first positioned as for a Schüller's projection and it is then rotated with the face away from the film at an angle of approximately 30°. The x-ray beam is directed cephalocaudal with an angle of 35°.

This view gives a "surgeon's eye view" of the key area of the attic, aditus and anterum. It usually shows the malleus and the incus (a portion of it) in the natural position within the tympanic cavity.

Chausse's III View

Chausse's III view is obtained by positioning the occiput on the film, the head is rotated approximately 10-15° toward the side opposite to the one under examination and the chin flexed on the chest. There is no angulation of x-ray beam.

This view provides visualization of the attic, aditus, mastoid antrum, and especially the anterior two-thirds of the lateral wall of the attic. In contrast, the Owen's view shows the posterior or aditus portion of the attic.

Transorbital View

Transorbital view is obtained with the patient's occiput to the film to magnify the orbit. The chin is slightly flexed until the orbitomeatal line is perpendicular to the film.

In this view, the petrous pyramid, especially the internal auditory canal, is clearly visualized through the radiolucency of the orbit. It also shows the cochlea, vestibule, and semicircular canals (Fig. 24-3).

Stenvers' View

Stenvers' view is obtained with the patient facing the film with the head slightly flexed and rotated 45° toward the side opposite to the side under examination. The x-ray beam is angulated 14° caudad. The long axis of the petrous pyramid becomes parallel to the plane of the film and the entire pyramid is well visualized, including its apex.

This view clearly shows the entire pyramid, arcuate eminence, internal auditory canal, porus acusticus, horizontal and vertical semicircular canal, vestibule, cochlea, mastoid antrum, and mastoid tip. The internal auditory canal may appear foreshortened because of rotation (Fig. 24-4).

Heavy exposure will bring out details of the petrous apex, while a lighter exposure will permit visualization of details of the mastoid structure.

2 Submentovertical View

Submentovertical (axial, basal) view taken from "under the chin" has the advantage of showing both temporal bones on the same film so that comparison of both sides can be made.

This view shows the external auditory canal, the eustachian tube, the middle ear with the incus and the head of the malleus, the mastoid air cells, the styloid process, the internal auditory canal, and petrous apex. It also shows such structures of the base of the skull as foramen ovale, foramen spinosum, and jugular foramen (Fig. 24-5). This view has the disadvantage of loss of clarity and detail of the ear structures because of increased antrum-to- film distance.

Towne's View

Towne's view is the anteroposterior projection with 30° tilt (from "above and in front"). As in the submentovertical view, the view allows comparison of both petrous pyramids and mastoids on the same film. The petrous apex, internal autidory canals, arcuate eminence, mastoid antruma, and mastoid process can be clearly identified. This is useful for evaluation of apical petrositis, acoustic neuroma, and cerebellopontine angle tumor (Fig. 24- 6).

Tomography and Polytomography

The use of special projections with various angulations of x-ray beam or of the patient's head, which are indispensible in conventional radiography to visualize certain structures, is not required in tomography. It has the following advantages: the positioning is simple and the projection easily reproducible; the ear structures can be visualized under the same angle of surgical approach; it can follow the same plane as used in the histologic section; and the cut of certain structures can be made at a right angle to the axis.

Of the five tomographic projections, two of them, frontal and lateral, are basic; the other three (axial, horizontal, and Stenvers') are complementary according to the area of pathology and examination desired. Tomography is a technique which allows visualization of a desired structure while obscuring those structures in front of and behind it. With the Philips- Massiot polytome which furnishes a sufficiently thin cut and a high coefficient of distinction, it is possible to visualize clearly the small structures of the ear. The tomographic examination of the temporal bone consists of multiple sections obtaine 1 or 2 mm apart. In all projections both sides are examined so that the corresponding structures may be compared.

This type of multidirectional or hypocycloidal tomography is excellent for the study of: (1) congenital malformations, (2) inflammatory processes (cholesteatoma) Fig. 24-7, (3) traumatic effects (transverse and horizontal fractures, ossicular fractures, and/or dislocation), (4) neoplasm (glomus tumor, acoustic neuroma, and carcinoma (Fig. 24-8), and (5) otodystrophy (otosclerosis, Paget's disease, osteogenesis imperfecta, and fibrous dysplasia).

3 Carotid Arteriography

This is useful in vascular anomalies of the temporal bone (glomus tumor, aneurysm, etc). They may show soft tissue displacement of may show a tumor stain.

Retrograde Jugular Venogram

The jugular vein is catheterized and dye injected retrograde under pressure, filling the jugular vein and its tributaries. This is extremely useful in evaluation of collateral flow before ligation of the jugular vein, and for evaluation of the jugular bulb in anomalies and glomus tumors.

Posterior Fossa Myelography (Cisternogram)

Two to three millimeters of Pantopaque (iophendylate) are injected in the subarachnoid space by lumbar puncture. Under fluoroscopic control the contrast media is then moved into the posterior cranial fossa in Trendelenburg's position. This material outlines structures in the posterior fossa and is probably the most conclusive diagnostic test for acoustic neuroma. The absence of filling of the internal auditory canal and the demonstration of a filling defect in the cerebellopontine cistern are positive evidence of a space-occupying lesion.

Posterior fossa myelography is indicated: (1) when the audiometric, vestibular, and tomographic studies are indicative of a retrocochlear lesion, (2) when the audiometric and vestibular tests are suggestive of a retrocochlear lesion, and a tomographic study is positive, and (3) whenever the audiometric and vestibular tests consistently indicate a retrocochlear lesion in spite of a negative tomographic study to rule out the presence of a tumor limited to the cistern, or a tumor that is too small to produce changes in the bony outline of the internal auditory canal.

Combination Technique

A combination of the polytomography and posterior fossa myelography is useful in the diagnosis of a small tumor within the internal auditory canal.

Computerized Tomography

(See section Computerized Tomography).

Radiography of the Paranasal Sinuses

Radiographic examination of the paranasal sinuses consists of four standard projections (Waters', lateral, submentovertical, and Caldwell's), tomography, contrast radiography, and angiography.

4 Standard Projections

Waters View (Occipitomental, "Chin-Nose" Position

This posteroanterior occipitomental projection is taklen with the patient's head tilted upward so that his nose and chin are against the film surface. The petrous portion of the temporal bone is projected below the level of the maxillary sinus.

The maxillary sinuses are best shown in this view, followed by the frontal sinuses. The ethmoid sinuses are not well shown. A good view of the sphenois sinus and its septum is obtained through the open mouth (Fig. 24-10).

This view also shows such maxillofacial structures as nasal bones, frontal process of the maxilla, zygoma and its arch, and mandible (especially the coronoid process).

Other structures to be recognized include the oblique orbital line, the rim and floor of the orbit, superior orbital fissure (cranial nerves III, IV, V1, VI, ophthalmic vein), foramen rotundum (V2 - maxillary nerve), foramen ovale (V3 - mandibular nerve), zygomaticofacial foramen, infraorbital foramen, nasal ala, and upper lip.

Lateral View

In this view the sphenoid sinuses are shown to best advantage followed by the frontal, ethmoidal, and maxillary sinuses in that order (Fig. 24-11).

It also shows such maxillofacial structures as nasal bones, frontal sinus walls, the zygomatic process of the maxilla, the posterior wall of the maxillary sinus, the pterygoid plates, and the mandible. Other structures to be recognized in this view include anterior walls of the middle cranial fossa, the roof of the sphenoid sinus, the cribriform plate, the inferior turbinate, the coronoid process of the mandible, the zygomatic recesss, the pterygomaxillary fissue, caroticoclinoid foramen, carotid sulcus and soft tissues (tonsils, adenoids, earlobe, soft palate, and base of tongue).

Submentovertical View (Basal or Base View)

This view is obtained by passing x-rays at right angles through the base of the skull with the orbitomeatal line perpendicular to the central ray. In this view the sphenoid sinuses are shown to best advantage, followed by the posterior ethmoidal, maxillary, and frontal sinuses in that order (Fig. 24-12).

It shows such maxillofacial structures as the zygomatic arch, the body of the zygoma, and the mandible (especially condyle).

Other structures to be recognized include pneumatization of the pterygoid process and the greater wing of the sphenoid; the lateral three lines (1) orbital line - a straight line formed by the lateral wall of the orbit, (2) antral line - an S-shaped line formed by the lateral wall of the antrum, and (3) middle cranial fossa line - a C-shaped curve with concavity backward formed by the anterior wall of the middle cranial fossa; the pterygoid plate and pterygoalar

5 bar; nasal cavity; the lacrimal canal; incisive foramen; greater and lesser palatine foramina; inferior orbital fissure; choana; foramen ovale (V3 - mandibular nerve); foramen spinosum (middle meningeal artery); foramen lacerum; carotid canals; eustachian tube; internal and external auditory canals and jugular foramen; and soft tissues (nasal turbinates, adenoids, uvula, lateral wall of the nasopharynx, and membranous external auditory canal).

Caldwell View ("Forehead-Nose" Position)

This is obtained by positioning the nose and forehead against the cassette with the external auditory meatus and outer canthus of the eye forming a line perpendicular to the cassette. The x-ray tube is tilted caudally 15-20°.

In this view the frontal sinuses are best shown. The ethmoidal sinuses, particularly the orbital margin (lamina papyracea) are also well shown. The main cavity and lateral extensions of the sphenoid sinuses are recognizable. The posteromedial and inferolateral portion of the maxillary sinuses are usually visible (Fig. 24-13).

It shows such maxillofacial structures as the orbital margins, the zygoma, the zygomaticofrontal suture, the maxilla and the mandible.

Other structures to be recognized include the nasal cavity and its contents, floor and rim of the orbit, the infraorbital canal, the superior orbital fissure, the supraorbital foramen, Hyrtl's foramen (ophthalmomeningeal vein), lambdoidal suture, the foramen rotundum (always inferolateral to th lowermost portion of the superior orbital fissure) and soft tissues (palebral fissure and "pony-tail" hair style).

Tomography

Tomography is of great value in determining the presence or absence of fractures or bone destruction in the paranasal sinuses and nasal structures, particularly in the planning of surgical or radiotherapeutic procedure. It is essential in the preoperative study of the diseases of the posterior ethmoid and sphenoid sinuses, and transsphenoidal hypophysectomy.

Multidirectional tomography (polytomography) is significantly superior to linear tomography.

Contrast Radiography

Radiopaque contrast media is used to outline anatomic or pathologic abnormalities within the paranasal sinuses, nasal cavity, and nasopharynx, such as cysts, polyps, neoplasms, oroantral fistula, and choanal atresia.

Carotid Arteriography

This may help delineate both benign and malignant lesions of the sinuses. In malignant lesions, soft tissue displacement, abnormal vascular pattern, or a tumor stain may be shown. It is particularly useful for evaluation of angiofibromas of the nasopharynx. By the use of

6 subtraction techniques, excellent visualization of occult extensions of the tumor with its vascular connections may be obtained.

Selective arteriography is extremely useful in the investigation and management of persistent and uncontrollable epistaxis prior to any surgical intervention.

Table 24-1 lists the foramina found at the base of skull, their contents, and the radiologic view in which they are best visualized.

Table 24-1. Foramina in the Base of Skull

Anterior Cranial Fossa

Foramen caecum --> Emissary vein from nose to superior sagittal sinus ==

Anterior ethmoidal foramen --> 1. Anterior ethmoidal vessels 2. Nasociliary nerve --> Lateral

Foramina in cribriform plate --> Olfactory nerves ==

Posterior ethmoidal foramen --> Posterior ethmoidal vessels/nerves --> Lateral

Middle Cranial Fossa

Superior orbital fissure --> 1. Ophthalmic vein 2. Orbital branch of middle meningeal artery 3. Oculomotor nerve (III) 4. Trochlear nerve (IV) 5. Ophthalmic division of trigeminal (V1) 6. Abducens nerve (VI) 7. Recurrent branch of lacrimal artery --> 1. Caldwell's 2. Waters'

Optic foramen --> 1. Optic nerve 2. Ophthalmic artery --> Oblique orbital (Rhese)

Foramen rotundum --> Maxillary division of trigeminal (V2) --> 1. Caldwell's 2. Waters'

Foramen ovale --> 1. Mandibular division of trigeminal (V3) --> 1. Base 2. Waters'

7 Foramen lacerum (carotid canal) --> 1. Internal carotid artery 2. Sympathetic carotid plexus 3. Superficial petrosal nerve 4. Vidian nerve 5. Meningeal branch of ascending pharyngeal artery --> Base

Foramen spinosum --> 1. Middle meningeal artery 2. Recurrent branch of mandibular nerve --> Base

Posterior cranial fossa

Internal auditory canal --> 1. Facial nerve (VII) 2. Auditory nerve (VIII) 3. Internal auditory vessels --> 1. Stenvers' 2. Transorbital 3. Towne's 4. Base

Jugular foramen --> 1. Internal jugular vein 2. Inferior petrosal sinus 3. Transverse sinus 4. Meningeal branch from occipital and ascending pharyngeal arteries 5. Glossopharyngeal nerve (IX) 6. Vagus nerve (X) 7. Spinal accessory nerve (XI) --> 1. Base 2. Towne's

Stylomastoid foramen --> 1. Facial nerve (VII) 2. Stylomastoid artery --> Base

Hypoglossal canal --> 1. Hypoglossal nerve (XII) 2. Meningeal branch of ascending pharyngeal artery 3. Emissary vein from transverse sinus --> 1. Stenvers' 2. Towne's

Foramen magnum --> 1. Medulla oblongata and spinal cord 2. Spinal accessory nerve (XI) 3. Vertebral arteries 4. Anterior and posterior spinal arteries 5. Membrana tectoria

8 6. Apical ligament --> 1. Base 2. Towne's.

Radiography of the Larynx

Radiographic examination of the larynx consists of conventional projections (anteroposterior and lateral), tomography, positive laryngography, air-contrast laryngography, and cinefluorography.

Conventional Radiography

The anteroposterior (AP) and lateral views are commonly used.

Anteroposterior View

The AP view is of limited value in evaluation of the larynx itself because of the superimposition of the cervical spine. However, masses of the neck lateral to the larynx and distortion and/or displacement of the upper airway are shown.

Lateral View

The lateral view is of greater value and shows the outline of the base of the tongue and epiglottis, the vallecula, the hyoid, the aryepiglottic folds and arytenoids, the ventricles, the thyroid and cricoid cartilages, the subglottic space, and the prevertebral soft tissues (Fig. 24-14). This view is useful for evaluatiuon of tumors and fractures of the larynx, a foreign body in the larynx, hypopharynx, and upper esophagus, detection of calcification of normal and abnormal tissues, and evaluation of acute inflammatory conditions such as acute epiglottitis and retropharyngeal abscess. It also is useful for both pre- and postoperative evaluation of a thyrotomy and tracheotomy. The accuracy of the stent or mould placement for fractured larynx is also determined in this view.

Differential diagnosis of foreign body in the larynx, hypopharynx, and upper esophagus include:

1. Sialolith 2. Tracheal rings 3. Semiopaque ear rings 4. Osteophytes of the cervical spine 5. Calcareous streaks in scar tissues 6. Ossified centers of the hyoid bone 7. Calcified cervical nodes 8. Redisual dye from arteriography 9. Calcification in the laryngeal cartilages 10. Accessory ossification centers in the cervical spine 11. Calcified stylohyoid ligaments 12. Sesamoid laryngeal cartilages 13. Calcification in the vessels of the neck.

9 Tomography

Tomography is usually performed in the AP position and demonstrates laryngeal structures extending from the false cords to the upper trachea. The disadvantages of this technique are the amount of time consumed, difficulty of prevention of patients' movement between or during exposures, and radiation exposure to the patient. The most useful information provided from this study is obliteration of the laryngeal ventricles or subglottic extension of neoplasms.

Positive Contrast Laryngography (Fig. 24-15)

Instillation of contrast media under fluoroscopic guidance provides a means of studying and recording on film or videotape the physiologic and pathologic processes. This diagnostic study is particularly useful in the selection of patients for conservation surgery of the larynx since it helps to outline the extent of the tumor and identify areas of involvement that cannot be directly or indirectly inspected.

Under topical anesthesia the tip of the catheter is positioned in the pharynx just above the tip of the epiglottis. The contrast media (Dionosil) is instilled slowly as the patient inspires, phates, expires, and executes the Valsalva maneuver. Two major drawbacks are: need for a topical anesthetic and the amount of time required for this study.

Powdered tantalum has been used as a medium for laryngography. Several features of powdered tantalum must be recognized: (1) is potentially explosive, (2) particle size is not uniform, and (3) prolonged retention has been demonstrated in animal studies.

Air Contrast Laryngography

Laryngography using high kilovoltage and heavy filtration provides information similar to positive contrast studies in the evaluation of laryngeal tumors. It is useful in the examination of patients with neoplasms who are unable to tolerate a positive contrast study.

Xeroradiography

This technique, which is well accepted in mammography for its remarkable ability to record differences in soft tissue density, provides excellent images of soft tissues of the neck with great contrast in the lateral projection.

Xeroradiography may be combined with zonography using the polytome machine - xeroradiographic zonography. It gives an excellent tomographic view of soft tissues of the larynx and hypopharynx in the frontal projection.

Roentgen exposures of approximately four times that of conventional soft tissue x-ray views are required for this method. Xeroradiography permits excellent imaging of mucosal surfaces, calcifications, and cartilages. It may obviate the need for repeated endoscopy, particularly in children with subglottic and tracheal stenoses, making this a major area of application.

10 Radiography of the Tracheobronchial Tree

Conventional chest films and tomograms provide considerable information concerning the tracheobronchial tree. However, bronchography is far more fruitful. It offers valuable information concerning not only congenital, inflammatory, and neoplastic lesions of the bronchi but provides information in certain parenchymal diseases such as alveolar lymphoma, alveolar cell carcinoma, and organized or unresolved pneumonia.

Methods of Bronchography

In those patients in whom the studies of all bronchial segments ("lung mapping") is desired, after suitable topical anesthesia, a soft rubber catheter is passed through the nose or the mouth into the trachea. When selective bronchography or brush biopsy of a lesion is desired, a trancricoid approach is used. The latter method is faster and less annoying to the patient. It requires a smaller amount of topical anesthetic and has the advantage of permitting selective studies of individual bronchi and allowing for brush biopsy. Dionosil (oily or aqueous) is the contrast media of choice. Aqueous media is slightly more irritating to the bronchial mucosa and requires a greater amount of topical anesthetic. Recently, the use of barium sulfate and powdered tantalum for bronchography has been suggested. Both have the advantage of being chemically inert.

Radiography of the Esophagus

Radiographic examination of the esophagus usually is achieved by barium swallow, using both thick (better coating of the mucosa) and thin barium mixtures.

Fluoroscopy and spot films are often sufficient to fulfill the diagnostic needs. However, cineradiography improves the functional and anatomic evaluation especially in the study of pathophysiology of swallowing.

A small cotton pedget soaked in barium and swallowed may catch or hold on a foreign body. Capsules of various sizes filled with barium and swallowed may demonstrate a stricture and its severity. A water-soluble contrast is used when an esophageal perforation is suspected.

The examination is conducted in both upright and recumber positions, using posterior, anterior, lateral, and oblique views. Inspiration, expiration, and the Valsalva maneuver also are used to note the esophageal position and intrathoracic dynamics.

Miscellaneous

Sialogram

Injection of radiopaque material into the salivary glands via the duct orifice will demonstrate abnormalities of the ductal system such as stricture, fistula, ectasia, or neoplasm and abnormalities within the ductal system such as radiolucent calculi.

To perform sialography the duct orifices of the parotid (Stensen's) and/or submandibular (Wharton's) first must be topically anesthetized and dilated to permit a no. 60

11 PE catheter. Pantopaque is slowly injected into the catheter until the patient complains of discomfort in the gland. It is important to fill the duct to the patient's tolerance rather than to a predetermined volume. Usually, about 1 mL will produce a satisfactory filling. After the x-ray examination the patient is instructed to chew on a fresh lemon for 1 minute. The normal gland will expel the contrast material within 5 minutes in response to this potent salivary stimulus.

The radiographs are taken with the patient seated in the PA, tangential, and lateral projections. These same views are repeated following injection of contrast, and again following emptying of the glands.

Sialography is helpful in determining if a lesion is inflammatory or neoplastic, whether it is an encapsulated or invasive lesion. The location of calculi in the duct or gland may be ascertained. Sialography is contraindicated in the presence of acute inflammatory disorders and when a history of sensitivity to iodine exists.

Plain films are made routinely to determine the adequacy of exposure and to detect radiopaque abnormalities in or around the salivary glands such as foreign bodies, calculi or calcifying disorders, and to determine if abnormalities or adjacent osseous structures exist.

Radiosialography (Salivary Gland Scanning)

A salivary gland scan utilizes the same instrumentation and basic scintiscan techniques employed for thyroid scanning with technetium 99m pertechnetate. This is a newer diagnostic technique and not yet widely adopted. Radiosialography is useful in the following situations:

1. Diagnosing a Warthin's tumor. 2. Searching for occult primary tumors in cases of cervical metastases. 3. Confirming the presence and extent of neoplasm. 4. Occasionally, to distinguish between benign and malignant disease.

Tympanogram (Tympanic Clearance Study)

This is a method for studying eustachian tube function using radiopaque material in the middle ear.

Eaustachian tube function can be determined by introducing not more than 1 mL of radiopaque material such as Pantopaque into the tympanic cavity through an intact or perforated tympanic membrane. A film is taken immediately in the Stenvers' position. After 10 minutes a second film taken in the same position will fail to show contrast material in the tympanic cavity if the eustachian tube function is normal. Retention of the dye indicates tubal disease.

Nasopharyngogram (Contrast Nasopharyngography)

Examination consists of submentovertical and lateral projections. The submentovertical view demonstrates the lateral walls of the nasopharynx while the lateral projection demonstrates the roof and posteriro walls of the nasopharynx as well as the nasopharyngeal

12 surface of the soft palate. If tumor growth is suspected to involve the eustachian tube, additional films are taken during a modified Valsalva maneuver. This study is useful for precise location and extension of tumors of the nasopharynx and adjacent structures. Premedication is not necessary. The patient is placed in a supine position with shoulders and trunk elevated to permit maximal extension of the neck, thus assuring a satisfactory submentovertical view of the base of the skull. The nostrils are sprayed with local anesthetic; contrast medium, 15-20 mL for adults, is then used.

Evaluation of Facial Bone Injuries

For the evaluation of the nasal bones, the right and left lateral, the superoinferior axial occlusal, and the Waters' views are usually taken. Lateral views reveal depression or elevation of nasal bone fragments, whereas superoinferior axial views show medial or lateral displacements of nasal fractures. The Waters' view also will show fracture and displacement of each nasal bone and the frontal process of the maxilla.

A facial bone series should include, in addition to the four standard sinus projections, an underexposed submentovertical view of the zygomatic arches, and the exaggerated Waters' view to demonstrate fracture of the infraorbital rim and fracture-dislocation of the zygoma and zygomatic arch.

Pantomography (Panoramic Radiography)

A Panorex dental x-ray machine provides a panoramic view of the entire mandible and the anterolateral aspects of both maxillary sinuses. The x-ray beam has an aluminium filter and a narrow slit-beam which moves horizontally from right to left (or vice versa) producing successive images on the film which in turn moves at a synchronized speed. The film is 12 in long and requires approximately 24 seconds for total exposure. It is useful for evaluation of pathologic conditions of the mandible and maxilla particularly for pre- and postoperative evaluation of mandibular fractures and tumors.

Orbitogram (Orbitography)

This may be used for diagnosis of a blowout fracture of the orbit. Five to ten milliliters of water-soluble contrast media (Hypaque) are injected into the extraconal space along the floor of the orbit in conjunction with hyaluronidase (Wydase). Typical orbitographic appearance of blowout fractures include demonstration of fluid level of contrast medium in the maxillary sinus, herniation of the orbital contents through the orbital floor, and depressed bony fragments. Complications from this procedure include perforation of the eyeball, retrobulbar hemorrhage, central retinal artery spasm, drug idiosyncrasy, transient or permanent loss of vision, and excessive swelling of eyelid. This procedure is not recommended for evaluation of blowout fracture. The conventional Waters' view and laminogram are sufficient for diagnosis of blowout fractures.

Xerosialography

Sialography using xeroradiography is a superior method of examining the salivary glands, and affords better details, especially in ducts overlying bone, than does film recording.

13 Advanced Radiology in Otolaryngology

Diagnostic Ultrasound

Diagnostic ultrasound has application to otolaryngology in the evaluation of lesions of the orbit and neck.

Sound waves can be recorded as they are reflected back (echoed) from surfaces they encounter. Diagnostic ultrasound employs high-frequency sound waves in a similar manner to sonar, the military technology to which ultrasound owes its origins.

Low-energy sound waves with frequencies between 2.5-10 million Hertz (MHz) are introduced into cervical structures by a hand-held transducer that can be moved over the skin by the examiner. Unimpeded sound transmission is ensured by coating the skin with a coupling agent such as vegetable oil. As sound waves pass through the skin and underlying tissues, they encounter interfaces with different impedance characteristics between tissues and organ structures. At any interface, these sound waves may be reflected, refracted, or transmitted; those sound waves that are reflected back to the transducer, which serves the dial purpose of sound generator and receiver of returning echoes, are converted into electric impulses that can be displayed on an oscilloscope screen as a spike (A mode scan) or a dot (B mode scan).

As A mode scan echoes are represented as deflections arising from a baseline on the oscilloscope screen, the distance of any given spike or deflection from the left end of the base line varies with the actual distance from the patient's skin to the echo-reflecting surface. These distances may be measured against a scale of known magnitude.

Orbital and Sinus Ultrasound

This can now accurately detect, delineate, and differentiate many secondary orbital massess and infiltrates, including mucocele, infection or abscess, or tumor, originating in the surrounding paranasal sinuses. Primary intraorabital disease also can be identified. An A mode ultrasound is a simple, useful diagnostic tool in the evolution of maxillary sinus diseases. It can distinguish fluid from solid masses within the antrum.

Cervical Ultrasound

This already has been extensively used in the assessment of thyroid disease, but it can well be applied to a variety of other cervical lesions, beyond the thyroid gland.

Cystic structures, such as branchial cleft and the thyroglossal duct cysts, appear as sharply defined structures containing virtually no echoes within the circumference. These phenomena are related to the discrete walls cysts tend to have, and to the absence of echogenic tissue interfaces within the confines of these walls. Solid masses, on the other hand, such as salivary gland tumors, are not well defined and their central portions contain many echoes. They are not so well defined because their acoustic properties are not much different from those of the surrounding tissue structures. They contain many echoes because the multiple tissue interfaces within them easily reflect sound waves.

14 With the use of ultrasonography, it is now possible to recognize disruption of the normal integrity of the thyroid alae by infection, fracture, or tumor.

Nuclear Medicine

Nuclear medicine, aside from its essential therapeutic applications, provides a relatively noninvasive form of nonroentgenographic diagnostic imaging. Nuclear medicine utilizes a variety of radioactive drugs that become localized in specific organs to produce diagnostic images. Images are recorded on cameras or scanners sensitive to the gamma ray emissions of radioactive pharmaceuticals. These pharmaceuticals are chosen for their physicochemical propensity to accumulate in specific organs, organ systems, or pathologic tissues; thus, the anatomic distribution of a physiologic process can be recorded.

Thyroid Scanning

Thyroid scanning is one of the most well-established and best-known imaging procedures of nuclear medicine.

The normally functioning thyroid gland traps and organizes iodine, and the rate of accumulation and pattern of distribution within the gland are useful indicators of thyroid disease. Twenty-four hours after an oral or intravenous dose of approximately 50 microCi of iodine 131, images of the gland are obtained and these images are correlated with physical examination of the neck.

Recently, technetium 99m pertechnetate ion has been used in place of 131I. This radionuclide has a 6-hour half-life and emits pure gamma rays, affording a substantial reduction in thyroid irradiation when compared with radioiodine.

Palpable nodules may be identified as "hot" (functioning) or "cold" (nonfunctioning). A neck mass may be shown to be related to or remove from the thyroid gland. The presence of ectopic thyroid tissue, as in lingual thyroid or thyroglossal duct cyst, may be assessed. When ectopic thyroid tissue is demonstrated, the presence or absence of functioning thyroid in the normallocation is of significance if surgical removal of the ectopic thyroid can be considered.

Radiotherapy treatment in childhood is an important cause of thyroid cancer. The patients who received radiation to the neck in childhood for the treatment of thymus and other conditions should undergo periodic thyroid scanning, even when the thyroid is normal to palpation, to detect the early development of thyroid cancer.

In the 1930-1950 era, radium irradiation of the nasopharynx was used to control hyperplastic adenoids. Because of the technical characteristics of this applicator, sufficient radiation was not applied to the thyroid by this technique to stimulate the development of thyroid malignancies. No malignancies have been reported thus far as a result of this treatment.

15 Salivary Gland Scanning

A salivary gland scan utilizes the same instrumentation and basic scintiscan techniques employed for thyroid scanning with technetium 99m pertechnetate. This radionuclide is physiologically trapped by the thyroid and concentrated in the salivary glands and excreted in the saliva.

The parotid and submandibular glands show prompt and symmetric accumulation with an intensity approximating that of the thyroid gland. After 20 minutes the patient is given a sour candy or lemon drops and the images show a washout of activity from the glands and indicate patency of the ducts.

Salivary gland dysfunction is demonstrated by focal or generalized delay in accumulation of activity. Xerostomia, caused by Sjögren's syndrome or Frey's syndrome, produces a delay or a reduction or even absence, of a concentration within the salivary glands. Focal lesions, as in sialadenitis, salivary gland tumors, abscesses, and duct obstruction due to calculus, also may be identified.

Mixed salivary gland tumors may show a normal pertechnetate concentration or reduced function, depending on the mixture of cell types and the integrity of the duct system. Warthin's tumors, however, are generally hyperfunctioning on the scan, and this may make possible an appropriate differential diagnosis of a mass lesion.

Bone Scanning

Polyphosphates, pyrophosphates, and diphosphonates labeled with 99mTc ("technetium phosphates") are avid bone localizers.

Technetium phosphate localization in bone is related to the metabolic activity of the bone. The uptake of the radioactive tracer demonstrates the rate of osteoblastic activity, the presence of collagen or immature osteoid, and the integrity of the blood flow to the region. Local increases in uptake may occur in response to bone stress, in the reparative process in the presence of trauma or inflammation, or in reaction to osteolytic or osteoblastic tumor deposits.

Bone scanning is useful in detection of:

1. Traumatic conditions. 2. Inflammatory conditions. 3. Neoplasm. 4. Temporomandibular arthritis (a focal hot spot at TMJ indicates articular disease).

Brain Scanning

Technetium 99m pertechnetate is used.

Rapid sequential images taken over the head in the anterior, posterior, or vertex projection show the first transit of the bolus through the carotid arteries and into the

16 hemispheres. The region of the circle of Willis and the middle cerebral and anterior cerebral artery distributions are visualized. Local areas of hypervascularity or ischemia may be defined. Immediate blood pool images in the first 3 minutes show areas of hypermia within the brain or calvarium.

Delayed brain scan images viewed approximately 2 hours following injection of the radiopharmaceutical show abnormal accumulation of radioactivity in intracranial lesions.

The normal blood-brain barrier prevents the diffusion of pertechnetate ion into normal brain substance, but in the presence of tumor, infarct, abscess, contusion, or hematoma, the affected tissues with increased capillary permeability permit "staining" of the lesion by the radioactive tracer. On the basis of the location, configuration, and appearance of the lesion in the flow, blood pool, and delayed brain images, a differential diagnosis may be made with reasonable accuracy.

Brain scanning is useful in:

1. Primary brain tumors (tumor as a "hot" area surrounded by the normal "cold" brain tissues). Acoustic neuromas show an avid uptake of pertechnetate, but despite this favorable property, these tumors frequently are not detected on the brain scan if they are small at the time of examination. 2. Meningioma. 3. Arteriovenous malformation. 4. Brain abscesses.

Tumor and Infection Seeking Radionuclides

Gallium 67 citrate has an avidity for certain neoplasms and pyogenic infections. The exact mechanism is unclear, but the radiopharmaceutical appears to be concentrated in the lysosomes of macrophages and reticuloendothelial cells. Thus, there is nonspecificity of uptake in both tumors and infections. Other agents such as bleomycin lebeled with indium III have been used for tumor localization, and in vivo labeled leukocytes have been used for inflammation scanning.

Although gallium does not localize equally well in all types of neoplasm, it is particularly well suited to the staging of a lymphoma detected in the cervical nodes or nasopharynx. The gallium scan is most useful in areas not accessible to conventional lymphangiography. The accuracy below the diaphragm is less than that in the chest and axilla, partly because bowel accumulation of gallium may confuse the image.

Computerized Tomography

Computerized tomography (CT), also called computerized axial tomography (CAT) is a major advance in diagnostic radiology. Since its introduction and clinical application in 1973 computed tomography (CT) has made enormous contributions in the areas of diagnostic medicine, treatment planning, and follow-up.

17 Clinical Application

CT scanning may be of value in any clinical situation in which tomography and/or contrast examinations may prove useful.

CT scanning has been found to be of considerable clinical value for the evaluation of anatomic and pathologic conditions (trauma, benign and malignant tumors, congenital anomalies, inflammatory diseases, etc) of such structures of head and neck as:

1. Temporal bone. 2. Paranasal sinuses. 3. Orbit. 4. Nasopharynx, oropharynx, parapharyngeal space, and floor of mouth. 5. Larynx and hypopharynx. 6. Salivary glands.

Accurate, highly detailed, cross-sectional images of the internal auditory canal, vestibule, cochlea, vestibular aqueduct, semicircular canals, ossicles, and middle ear space are not attainable because of recent advances in CT technology and image quality. Zoom reconstruction and the ability to scan 1.5 mm thins sections are examples of these advances. Zoom reconstruction allows high-resolution, magnified-image reconstruction of selected regions of interest without the need for additional radiation exposure or scan time for the subject.

Acoustic Neuroma

At present, a major application of CT scanning is its role as the initial radiologic study in the investigation of acoustic neuroma, meningioma, and other lesions in the cerebellopontine angle.

It is now agreed that computed tomography provides an excellent screening technique permitting diagnosis of acoustic neuromas over 2 cm in size when the examination is carried out with contrast enhancement. Since acoustic neuromas have tissue densities equal to those of surrounding brain, enhancement with contrast is necessary to produce increases in density and well-circumsised margins.

All tumors over 2 cm in diameter usually are shown with contrast enhancement. The 20% false-negative studies may occur in patients with tumor sizes less than 2 cm.

While a positive CT scan eliminates the need for pneumoencephalography and posterior fossa myelography, angiography is necessary to rule out a vascular lesion such as an aneurysm or an elongated ectatic basilar artery.

It has become clear that the conventional CT scan cannot detect acoustic tumors in the cerebellopontine angle (CPA) less than 1.5 cm in size, or tumors that lie wholly within the internal auditory canal (IAC). However, acoustic neuromas as small as 0.8 cm have been demonstrated on computed tomographic scanning. A promising adjuvant is the introduction of water soluble myelographic contrast agents to the basal cisterns (via lumbar puncture). This

18 intrathecal enhancement should lower the limit of reliable resolution for acoustic neuromas to well below 2 cm.

When screening studies such as conventional film and polytomography are positive and agree with the clinical and audiometric examinations, a CT scan should then be performed. If the latter is negative, Pantopaque myelography or air CT should follow.

The decision to proceed to an invasive radiologic study for a small tumor has been recently based on results from brain stem evoked audiometry (BSEA). When BSEA is negative together with other audiometric studies, then invasive radiologic studies are not indicated.

A positive BSEA test indicating a retrocochlear lesion and combined with a negative CT scan should be followed by posterior fossa myelography or cisternography combined with CT.

Posterior fossa myelography with Pantopaque remains the best diagnostic procedure for the small acoustic tumor (>90% accuracy). No false-negative studies have been reported. False-positive studies can occur rarely because of (1) a small IAC, (2) adhesions at the porus due to arachnoiditis, (3) large loops of the anterior inferior cerebellar artery causing either a filling defect or obstruction to the flow of Pantopaque.

Brain Abscess Secondary to Ear and Paranasal Sinus Infections

Computerized axial tomography has revolutionized the treatment of intracranial abscesses optimizing the timing for medical and surgical management. Serial CAT studies, either preoperatively or postoperatively, at regular intervals allow accurate documentation of the abscess site, encapsulation, and extension of surrounding cerebral edema. This excellent noninvasive technique has made better medical and surgical management of brain abscess possible. The morbidity and mortality of sick patients is greatly reduced with the availability of the CAT scan.

Maxillofacial Trauma

1. Computed tomography (CT) has become the key diagnostic modality in the evaluation of head trauma. 2. CT is of great value for evaluation of zygomatic, orbital floor, nasoethmoidal complex, LeFort, temporal bone, frontal sinus, and mandible fractures. 3. More importantly, concomitant intracranial injuries including epidural and intracerebral hematomas, traumatic encephalocele, and pneumoencephalus are readily recognized. 4. In addition, facial and orbital soft tissue structures including the globe, optic nerve, orbital fat, and extraocular muscles are easily examined by adjusting the CT level and window settings. Overall, CT yielded additional information not available from polytomography.

19 Laryngeal Diseases

1. CT provides a noninvasive, quick, and effective radiologic investigation for the larynx. 2. It can be done without risk in cases of respiratory obstruction and after suspected laryngeal injury. 3. CT gives an accurate assessment of laryngeal anatomy and involvement by tumor, particularly of the preepiglottic space, parachordal area, anterior commissure, and cricoarytenoid area. These are all areas not well assessed by conventional tomography. 4. A major limitation of CT is its inhability to define a transition zone from the false to the true cords. The ventricle is identified in approximately 10% of patients. CT is felt to be entirely complementary to conventional tomography. Conventional tomography is superior in showing the ventricles, the thickening of the false and true cords, and subglottic extension. 5. CT is recommended as the initial radiologic procedure when additional diagnostic information is required to supplement the findings of laryngoscopy. CT provides information regarding deep penetration of tumor, including cartilaginous invasion, and about the inferior extension of neoplasm, including the subglottic area. This knowledge helps to determine whether conservation surgery as opposed to total laryngectomy is possible. 6. With the newer technology, the reduced radiation (which is less than one-half that of conventional tomography), and the decreased expense (now comparable to that of laryngography alone), eliminates the need for conventional laryngography and tomography examinations.

20 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 25: Head and Neck Anesthesia

Local Anesthesia

Definitions

Local anesthesia is the loss of sensation in a circumscribed area. Local anesthetics are drugs thart block nerve conduction when applied locally to nerve tissue in appropriate concentrations. In addition, clinically useful local anesthetics have the following properties:

1. The nerve block is reversible.

2. The time of onset, and duration of blockade of the nerve fiber is predictable for common usage.

3. The drug is nonirritating to the tissue to which it is applied.

4. The drug is permeable and diffusable.

5. The drug has a high therapeutic index.

6. The drug is water soluble and chemically stable.

Mechanism of Action

Local anesthetics prevent the conduction of nerve impulses. They act by interfering with ionic exchange at the nerve cell membrane and by stabilizing the membrane against the generation of an action potential.

Chemistry

The local anesthetics consists of three parts: aromatic lipophilic group, intermediate chain, hydrophilic group.

The common local anesthetics have as an intermediate chain either an ester, i.e. cocaine, procaine, or an amide linkage, i.e. lidocaine (Xylocaine), mepivacaine.

The terminal hydrophilic (amine) group is able to combine with an acid and form a water soluble salt.

The base unionized form is more lipid soluble and is the form that penetrates the neural membrane and produces anesthesia. The pKa of the particular drug and the pH of the solution determine the ratio of salt to base (as dictated by the Henderson-Hasselbalch equation) and therefore, the amount of drug in the pharmacologically active form. When the tissues into which a local anesthetic is introduced are acidotic, a larger proportion of the drug

1 is in the inactive (salt) farm. This accounts for the diminished activity of local anesthetics in infected areas.

Uptake, Metabolism, and Excretion

Most local anesthetic agents are absorbed rapidly into the bloodstream from the mucous membranes and subcutaneous tissues. Certain sites of particular interest to the otolaryngologist, such as the laryngeal and tracheal mucous membranes, are associated with such rapid uptake of local anesthetics that blood levels approach that achieved with intravenous administration.

Amide type drugs are metabolized by the liver in a complex series of steps beginning with N-dealkylation. Ester type drugs are hydrolyzed by cholinesterases in the liver and plasma. Both degradation processes depend on enzymes which are synthesized in the liver and therefore, both will be compromised in a patient with parenchymal liver disease.

Many of the end products of catabolism of both esters and amides are water soluble and are excreted to a large extent in the kidneys.

Toxicity

Local Toxicity

Local toxicity is a reaction of tissue at the site of injection. These include reactions of the skin and mesenchymal tissues (cellulitis, ulceration, abscess formation, tissue slough) as well as lesions of the peripheral nerves (neuropathy). The most common causes of local tissue reactions include:

1. Faulty technique: contamination of the local anesthetic agents and traumatic administration.

2. Reactions from the local anesthetic agent itself.

3. Reactions from preservatives and vasoconstrictor agents added to the local anesthetic.

General Toxicity

General toxicity includes systemic reactions which occur due to absorption of a given drug into the general circulation (Table 25-2). These may be due to an excessively high blood level, allergy, or miscellaneous causes.

Table 25-2. Rate of Topical Absorption in Decreasing Order

Tracheobronchial tree, nose, pharynx, larynx, esophagus.

1. A toxic blood level is the result of a drug overdose. This can be achieved by rapid absorption, excessive dose, and/or inadequate metabolism and redistribution. Most often a

2 toxic overdose is a result of carelessness in exceeding the recommended dosage for a particular drug, or inadvertent intravenous administration. Ninety-eight percent of systemic toxic reactions to local anesthetics are due to drug overdose.

Significant symptoms of toxic overdose of local anesthetic agents are confined to the central nervous system and cardiovascular system (see Tables 25-3 and 25-4). The central nervous system responses to local anesthetic agents are biphasic with stimulation followed by depression. Clinically, patients may appear agitated with confused and rambling speech. This excitation may proceed to seizures and coma. The direct cardiovascular effects of local anesthetics are those of depression. Both myocardial performance and peripheral vascular tone are diminished by increasing levels of local anesthetic agents.

As in most iatrogenic complications, the most effective treatment of local anesthetic toxic overdose is avoidance. This requires care in the choice of agent and administration.

When preliminary signs of overdose appear, O2 should be administered and a venous cannula should be secured. Symptoms of excitement may be treated with hypnotics (diazepam, barbiturates), although this should be done with caution so as not to exacerbate the subsequent cerebral depression. Likewise if seizures occur, antiseizure medication should be employed but with the realization that the subsequent coma may be exacerbated. The physician should be prepared for general supportive measures in the case of ultimate cardiovascular and respiratory collapse. This may include endotracheal intubation, mechanical ventilation and intravenous fluid and pressor therapy.

Table 25-3. Local Anesthetic Toxic-Symptoms.

1. CNS: Excitation. Cerebral cortex --> excitement, disorientation rambling speech, seizures. Brain stem --> tachycardia, hypertension, vomiting, sweating.

2. CNS: Depression. Cerebral cortex --> coma. Brain stem --> bradycardia, hypotension, apnea.

3. Cardiovascular system: Depression. Bradycardia. Hypotension. Shock.

4. Cardiorespiratory arrest.

5. Death.

3 Table 25-4. Prevention and Treatment of Toxicity.

1. Prophylaxis.

a. Avoid overdose.

b. Diazepam (Valium) premedication.

2. Maintain verbal contact with patient throughout surgery. Must be alert to early signs and symptoms of excitation.

3. Have an IV in place before administration of local anesthetics.

4. When toxic symptoms appear, stop surgery, give O2.

5. Maintain airway and ventilation.

6. Avoid giving further depressants if possible. However, IV Valium or Pentothal may be required to terminate seizure.

7. Fluid, pressor resuscitation as required.

2. True allergic reactions to local anethetics are an infrequent occurrence (2% of reported complications), and most commonly occur with ester derivatives. These may present as any of the gamut of allergic syndromes from relatively innocuous dermatologic signs to anaphylactic shock. The treatment of allergic reactions to local anesthetic agents involves the same strategies as for any allergic reaction.

Trying to choose an anesthetic technique for a patient with a history of "allergy" to local anesthetics is a frequent clinical problem. A careful history with documentation, if possible, should help sort out those with reactions to toxic overdose (see above) or miscellaneous reactions (see below) from those with true allergy. If allergy is confirmed, some authors suggest that utilization of the opposite class of drug (i.e. amide if ester was previously used) is a relatively safe approach. Dyclonine, which is neither amide nor ester, may be safely used in some cases where allergy to both classes of drugs are suspected. If doubt exists, one must consider alternative techniques (i.e. general anesthesia).

3. Miscellaneous reactions included those adverse reactions which are not specific to the local anesthetic agent per se. An inappropriate response to the needle used for administration or an increased sensitivity to the preservative in the drug are examples. A unique adverse reaction occurs with the local anesthetic prilocaine. When used in excess of 500 mg in an adult, a significant fraction of the patient's hemoglobin is reduced to the methemoglobin state. Methemoglobin has a diminished ability to transport oxygen to peripheral tissues. The treatment of methemoglobinemia caused by prilocaine overdose is the slow intravenous administration of methylene blue, 1% solution, total dose 1-2 mg/kg.

4 Local Anesthetic Agents (See Table 25-1)

Cocaine

Cocaine was the earliest recognized local anesthetic and is the only agent that is naturally occurring. It was introduced into clinical practice for topical anesthesia by Sigmund Freud and Karl Koller in 1884 and for nerve trunk blockade by William Halsted in 1885.

Cocaine is unique among local anesthetic agents in its ability to block the reuptake of norepinephrine at adrenergic nerve endings. It is this metabolic action which accounts for its side effects of vasoconstriction, tachycardia, hypertension, "sensitization of the myocardium to catecholamines", mydriasis, cortical stimulation, and addiction.

Table 25-1. Concentration and Maximum Safe Doses of Local Anesthetics

Topical Infiltration Concentration/Max dose Concentration/Max dose

Esters

Cocaine &4-10% / 3 mg/kg Not used Procaine (Novocaine) Not effective 1-2% / 14 mg/kg adults / 5 mg/kg children Tetracaine (Pontocaine) 0.5-2% / 1 mg/kg 0.1-0.25% / 1-1.5 mg/kg Chloroprocaine (Nesacaine) Not effective 2% / 14 mg/kg Hexylcaine (Cyclaine) 5% / 3 mg/kg 1-2% / 7 mg/kg

Amides

Lidocaine (Xylocaine) 2-4% / 3 mg/kg 1-2% / 3 mg/kg sine epi / 7 mg/kg cum epi Mepivacaine (Carbocaine) Not effective 1-2% / 7 mg/kg Prilocaine (Citanest) Not effective 1-2% / 7 mg/kg Bupivacaine (Marcaine) Not effective 0.25-0.75% / 3 mg/kg

Piperidine

Dyclonine (Dyclone) 0.5% / 4 mg/kg Not used

Epinephrine 1:1000-1:100.000/1mg 1:1000-1:100.000/1mg with halothane anesthesia 10 mL of 1:100.000 (0.1 mg) can be used over a 10 minute period, or 30 mL over 1 hour (0.3 mg).

& (10% solution = 100 mg/mL; 1% solution = 10 mg/mL).

Other drugs which interfere with catecholamine catabolism, such as monoamine oxidase inhibitors (MAOI) may interact with cocaine and cause a hypertensive crisis.

5 Cocaine is an extremely potent topical anesthetic agent and an extremely toxic drug. The maximum permissible dose topically is 2-3 mg/kg. The onset of action is immediate, and the duration is 45 minutes. It is decomposed by autoclaving.

Procaine Hydrochloride (Novocaine)

Procaine was first synthesized in 1905 by Einhorn as a result of a concerted effort to find a safer substitute for cocaine.

Procaine hydrochloride is a relatively weak local anesthetic agent of the ester type. It is inactive when applied topically. When used for infiltration, it is associated with a rapid onset (2-5 minutes) and a brief duration of action (45-60 minutes). It has a relatively toxicity, and a maximum recommended dose of 1000 mg. It is commonly used in 2% solution for infiltration.

Procaine is rapidly hydrolyzed by intravascular cholinesterase. Procaine may prolong the effect of succinylcholine (Anectine) which is also catabolized by cholinesterase.

Tetracaine Hydrochloride (Pontocaine)

Tetracaine is a potent anesthetic of the ester family. Its potency and toxicity are approximately 10 times those of procaine. It is effective when applied topically in a concentration of 1-2% and is associated with a rather delayed onset (6-12 minutes) and prolonged duration of action (1.5-2 hours). No more than 80 mg should be used for topical anesthesia of the upper respiratory tract.

Chlorprocaine Hydrochloride (Nesacaine)

Chlorprocaine is a halogenated derivative of procaine, and as such has similar pharmacologic properties. It is hydrolyzed more rapidly than procaine and is therefore less toxic. It is not useful for topical anesthesia. It is used in a 2% concentration for infiltration and the maximum recommended dose is 1 g.

Hexylcaine (Cyclaine)

Hexylcaine is an ester having somewhat greater potency and toxicity than procaine. It is most frequently used for topical application, where it provides a rapid onset (2-3 minutes) and moderate duration of action. Infiltration use has been limited by a high incidence of local irritation. The solution is stable and may be autoclaved.

Lidocaine Hydrochloride (Xylocaine)

Lidocaine is an aminoacetylamide. It has excellent penetrating powers and is effective by all routes of aministration, providing a rapid onset and a moderate duration of action (1 hour). The action may be prolonged by the addition of epinephrine in a concentration of 1:100.000 (1 mg of epinephrine per 100 mL of solution). For infiltration or nerve block, 1 and 2% solutions are used. A 4% solution is employed for topical anesthesia. The maximum

6 recommended dose for topical anesthesia in an adult is 200 mg (5 mL of the 4% solution) and for infiltration is 200 mg (without epinephrine) and 500 mg (with epinephrine).

The enhanced ability of lidocaine to suppress automaticity in ectopic myocardial foci has encouraged its use in the acute management of ventricular arrhythmia. A dose of 50-100 mg as an intravenous bolus is used for the purpose.

Mepivacaine Hydrochloride (Carbocaine)

Mepivacaine is an amide chemically related to lidocaine. It shares with lidocaine many clinical features. It is associated with less vasodilatation than that seen with lidocaine and has a slightly longer duration of action.

Prilocaine Hydrochloride (Citanest, Propitocaine)

Prilocaine has similar clinical properties to those of lidocaine except that it is more rapidly metabolized. When the maximum dose of 500 mg is exceeded, methemoglobinemia may result (see miscellaneous reactions, above).

Bupivacaine (Marcaine)

Bupivacaine is an amide chemically related to lidocaine. It shares with Xylocaine many clinical features. It is associated with an extremely long duration of action (2-4 hours). It is tightly bound to tissue and plasma protein, and is not associated with high blood levels when appropriately administered. Bupivacaine is used for infiltration and nerve block ina 1- 2% solution with a maximum recommended dose of 225 mg. Its high potency and long duration of action make it a useful agent for prolonged procedures.

Dyclonine Hydrochloride (Dyclone)

Dyclonine is neither an ester nor an amide. Therefore, it has been recommended for use in those patients who are allergic to both families of local anesthetics. It has a rapid oset of action (3-10 minutes) and a brief duration (30 minutes). It is used in a 0.5% solution for topical anesthesia and the recommended maximum safe dose is 300 mg in an adult.

Dibucaine Hydrochloride (Nupercaine)

Dibucaine is of the amide group. It is extremely potent for topical and infiltrative use. However, it has fallen out of common use because of a reported high incidence of local toxicity.

Piperocaine (Metycaine)

Piperocaine is similar to procaine but more toxic and with a longer duration of action. The concentration used is 0.5-1% solution for infiltration and 2-10% solution for topical use.

7 Miscellaneous

Cetacaine is a mixture of tetracaine and ethyl and butyl aminobenzoate. Forestierre's solution is a mixture of cocaine (4%), phenol, potassium chloride, and epinephrine, 1:1000. Bonnaine's solution is a mixture of cocaine (4%), methol, and phenol.

Premedication

Drug premedication is only a supplement to a supportive and informative preoperative visit.

Hypnotics

Barbiturates. The barbiturates are probably the most frequently employed of the hypnotics. They act principally by depressing cerebral cortical activity, but also may be associated with respiratory and cardiovascular depression. Pentobarbital (Nembutal) and secobarbital (Seconal) are the most commonly used of the short-acting barbiturates. They are administered orally or intramuscularly in a recommended dose of 50-200 mg for adult patients.

Chloral Hydrate. This is one of the oldest and safest hypnotics. It is especially useful in elderly patients in whom barbiturates may be contraindicated. The recommended dosage for adults is 0.5-1.0 g by mouth.

Antihistamines. Antihistamines such as hydroxyzine (Vistaril) and diphenhydramine (Benadryl) are useful for their sedative, antihistaminic, and antiemetic properties. They are commonly used to supplement the action of a narcotic premedicant. They are well tolerated and relatively safely administered to all age groups. Hydroxyzine and diphenhydramine are administered in dosages of 25-100 mg intramuscularly.

Narcotics

Morphine sulfate (10 mg) and meperidine (Demerol) (50-100 mg) are commonly used in premedication. These drugs are especially useful when pain is a component of the preoperative condition. Both these agents are associated with central nervous system and respiratory depression and on occasion nausea and vomiting.

Tranquilizers

Phenothiazines. These are useful preoperative medications, contributing excellent sedative, antiemetic, and antihistaminic properties. Many of the phenothiazines can be given orally as well as intramuscularly for preoperative medication. Commonly utilized premedicants in this group include: chlorpromazine (Thorazine) 15-50 mg, prochloroperazine (Compazine) 5-10 mg, and promethazine (Phenergan) 25-50 mg.

Benzodiazepines. Benzodiazepines are especially effective premedicants for local anesthesia because of the prophylactic protection they provide against seizures. Effective in

8 both oral and intramuscular administration, diazepam (Valium) 5-10 mg, and chlordiazepoxide (Librium) 25-50 mg are the most frequently used of this family.

Belladona Derivatives

Atropine sulfate (0.5 mg) and scopolamine (0.5 mg) are the two most commonly employed belladona agents. Used for their antimuscarinic properties, their most beneficial action is that of drying of secretions of the upper airway. Scopolamine is associated with more frequent central nervous system effects (sedation, excitation) and is less effective in preventing reflex bradycardia than is atropine.

One of the authors (KJL) uses 100-mg secobarbital (Seconal) PO 2 hours preoperatively; 8- to 10-mg morphine IM, on call; 8- to 10-mg diazepam (Valium) IM, on call. The use of valium also serves as an adjunct to protect against local anesthetic toxicity reactions, particularly in rhinoplasty or other procedures in which larger quantities of local anesthetic agents are used. The use of morphine cause pylorospasm, thus preventing absorption of the Seconal if given simultaneously. Besides the preoperative medication, it is essential to inform the patient preoperatively of the procedure "step by step" and what to expect throughout. This preoperative counseling has been referred to by Jackson as the "sermon".

Intravenous Sedation

Diazepam

Diazepam (Valium)(2.5-5 mg) given in slow intravenous increments, is a relatively safe and effective sedative. It is useful in supplementing local anesthesia to optimize clinical conditions. Its effectiveness for tranquilization and prophylaxis against local anesthetic- induced seizures has been previously stressed. Very rapid administration is occasionally associated with transient respiratory depression.

Innovar

Innovar is a mixture of droperidol (2.5 mg/mL) and fentanyl (0.5 mg/mL). When given slowly in small increments (o.5 mL) it may enhance intraoperative sedation during local anesthesia. When given too rapidly, it may be associated with hypotension and chest wall spasm.

Barbiturates

Sodium pentobarbital (Nembutal) and secobarbital (Seconal) when given in small increments intravenously (25-50 mg) may provide safe sedation to supplement local anesthesia. Too rapid administration may produce respiratory depression.

Block Techniques

In virtually all blocks, eliciting an appropriate paresthesia before injection of the agent helps to insure success.

9 Laryngoscopy, Tracheoscopy

The larynx and trachea receive their sensory nerve supply from the superior and inferior laryngeal nerves, which are branches of the vagus nerve.

1. Anesthesia may be provided to the larynx by the topical application of local anesthesia (using a laryngeal syringe) to the mucous membrane of the pyriform fossa (dep to which runs the superior laryngeal nerve) and to the laryngeal surface of the epiglottis and the vocal folds (Fig. 25-1).

2. Local anesthesia of the larynx and trachea also may be accomplished by the percutaneous infiltration of local anesthetic solution around the superior laryngeal nerve and the transtracheal application of local anesthetic to the tracheal mucosa.

For percutaneous infiltration, the superior laryngeal nerve is located as it pierces the thyrohyoid membrane (Fig. 25-2).

a. Palpate the greater cornu of the hyoid bone.

b. Insert a 25-gauge needle approximately 1 cm caudal to this landmark.

c. The needle is inserted to a depth of approximately 1 cm until the firm consistency of the thyrohyoid membrane is identified.

d. Inject of 3 mL of local anesthetic solution.

The transtracheal application of local anesthesia requires the insertion of a 25-gauge needle through the cricothyroid membrane in the midline (Fig. 25-3).

a. Introduce the 25-gauge needle in the midline between the thyroid and cricoid cartilages.

b. Puncture the cricothyroid membrane. This is readily felt as a "pop". Free aspiration of air with the attached syringe verifies the intratracheal position of the needle tip.

c. Instill 4 mL of local anesthetic solution. In addition to anesthesia of the larynx and trachea (1 and 2 above), the topical application of local anesthesia to the oropharynx is required for adequate visualization for laryngoscopy and tracheoscopy.

Reduction of Dislocated Temporomandibular Joint

In the common presentation of temporomandibular dislocation, the condyle rests on the anterior slope of the articular eminence (Fig. 25-4). There is intense pain and severe spasm of the surrounding mandibular musculature. Reduction of this dislocation may frequently be accomplished by the unilateral, intracapsular injection of local anesthesia.

1. With the head of the condyloid process locked anteriorly, the depression of the glenoid fossa is easily palpated.

10 2. The needle is inserted into the depression of the glenoid fossa, and directed anteriorly towards the head of the condyloid process.

3. When the condyloid process is contacted, the needle is slightly withdrawn.

4. Instill 2 mL of local anesthetic solution into the capsule.

Reduction and Fixation of a Mandibular Fracture

Complete anesthesia for reduction and fixation of a mandibular fracture requires adequate anesthesia of the maxillary and mandibular branches of the trigeminal nerve and superficial branches of the cervical plexus (Fig. 25-5).

1. The mandibular branch of the trigeminal nerve is readily anesthetized near its exit from the skull through the foramen ovale (Fig. 25-6).

a. A skin wheal is raised just over the posterior inferior surface of the mandibular notch.

b. An 8-cm needle is inserted transversely and slightly anteriorly to a depth of 4-5 cm where it comes into contact with the lateral pterygoid plate.

c. The needle is withdrawn slightly and directed in a more anterior superior direction to pass anterior to the pterygoid plate into the pterygopalatine fossa.

d. The needle is advanced another 0.5-1.5 cm until paresthesia is elicited. A total of 5-10 mL of local anesthetic solution is deposited.

The most frequent complications of mandibular and maxillary nerve block is hemorrhage into the cheek. This usually is managed conservatively. Subarachnoid injections and facial nerve blocks are two other rarely reported complications.

3. The superficial branches of the cervical plexus are easily blocked as they emerge along the posterior margin of the sternocleidomastoid muscle. Starting at the midpoint of the posterior margin of the sternocleidomastoid muscle, infiltration is accomplished along the posterior margin of this muscle using 10-15 mL of anesthetic solution.

Otology

The sensory innervation of the external ear is illustrated in Fig. 25.8. The middle ear receives its sensory innervation through the tympanic plexus (V3, IX, and X).

V3 --> Auriculotemporal nerve. IX --> Jacobson's nerve. X --> Auricular nerve.

11 Myringotomy

1. Inject the cartilaginous and bony junction of the external auditory canal.

2. Instead of introducing the local anesthetic through the classical 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock infiltration, infiltrate at 12 o'clock, 2 o'clock, 4 o'clock, 6 o'clock, 8 o'clock, and 10 o'clock. In this manner, other than the first injection site, the subsequent injection sites are already anesthetized before the needle prick. The patient feels one needle prick instead of the classic four pricks. For myringotomy alone, it is not necessary to infiltrate the skin of the bony canal wall, thus no local anesthetic agent should infiltrate into the middle ear cavity. (See: Complications of Local Anesthetic in Stapedectomy.)

Stapedectomy

In addition to the technique described for myringotomy, it is necessary to infiltrate the tympanomeatal flap. Besides assuring adequate anesthesia, this provides vasoconstriction (1% lidocaine (Xylocaine) with epinephrine 1:100.000) for hemostasis).

Complications. Two transient complications arising from the lidocatine, which migrated from the tympanomeatal flap to the middle ear cavity, have been noted in local anesthetic infiltration for stapedectomy:

1. Temporary facial nerve paralysis. This is due to the local anesthetic coming into contact with the dehiscent facial nerve. Patience and reassurance for a few hours will resolve the problem.

2. Violent vertigo with nystagmus (similar to Ménière's attack) can occur 45 minutes after the infiltration. Provided no damage has been done to the vestibular labyrinth, this is secondary to the effect of lidocaine on the membranous labyrinth through the oval or round windows.

These two complications are particularly distressing if they occur after an office myringotomy. Hence, it is the author's (KJL) advice that no infiltration in the skin of the bony canal wall is needed for myringotomy. The infiltration at the junction of the bony and cartilaginous canal will not reach the middle ear cavity.

Tympanoplasty and Mastoidectomy (Canalplasty, Meatoplasty)

This procedure is usually performed under general anesthesia. However, it is quite possible to have it performed under local anesthesia. In addition to the stapedectomy infiltration, postauricular and conchal infiltration are necessary (see Fig. 25-8 for the sensory innervation). The skin of the anterior canal wall needs to be anesthetized if surgery is to include that anatomic site.

12 Nasal Surgery

Nasal Polypectomy

Cocaine pledgets along the mucosal surfaces, as well as in contact with the sphenopalatine ganglion, supply adequate anesthesia for polypectomy. Occasionally it is necessary to supplement this with external infiltration, as in rhinoplasty.

Septoplasty and Rhinoplasty

The sensory innervation of the septum and external nose is illustrated in Figs. 25-9, 25-10, 25-11, 25-12, 25-13. Besides local infiltration as shown i nFig. 25-13, cocaine pledgets along the mucosal surfaces and sphenopalatine ganglion are used. For best hemostasis and anesthesia results, it is wise to wait at least 20 minutes before performing the surgery.

Table 25-5a. Nasal Sensory Innervation

V1 --> Lacrimal nerve. V1 --> Frontal nerve --> Supraorbital nerve. V1 --> Frontal nerve --> Supratrochlear nerve. V1 --> Nasociliary nerve --> Anterior ethmoid --> Anterior ethmoid cells. V1 --> Nasociliary nerve --> Cartilaginous nose, internally and externally. V1 --> Nasociliary nerve --> Med int nasal branch --> Upper and ant septum. V1 --> Nasociliary nerve --> Lat int nasal branch --> Lat wall of nose. V1 --> Nasociliary nerve --> Infratrochlear --> Skin of the root of the nose. V1 --> Nasociliary nerve --> Post ethmoid nerve --> Sphenoid / post eth cells.

Table 25-5b.

V2 --> Infraorbital nerve --> Ant sup dental nerve branches before the infraorbital foramen. It exits from the region of the anterior nasal spine to innervate that region. Thus it is necessary to inject this area to achieve anesthesia for rhinoplasty. V2 --> Infraorbital nerve --> The rest of the nerve exits at the infraorbital foramen to innervate the palpebra, conjunctiva, nasal, labial areas.

Table 25-5c.

V2 - Sphenopalatine ganglion --> Greater palatine nerve --> Soft and hard palate. V2 - Sphenopalatine ganglion --> Greater palatine nerve --> Nasal branches to the floor of the nose. V2 - Sphenopalatine ganglion --> Greater palatine nerve --> Anastomose with long sphenopalatine nerve. V2 - Sphenopalatine ganglion --> Lesser palatine nerve --> Soft palate and tonsil. V2 - Sphenopalatine ganglion --> Long sphenopalatine nerve --> Root of nose --> Septum and vomer --> Incisive foramen --> Hard palate mucosa --> Anastomose with greater palatine nerve. V2 - Sphenopalatine ganglion --> Long sphenopalatine nerve --> Superior and middle conchae and posterior septum.

13 V2 - Sphenopalatine ganglion --> Short sphenopalatine nerve --> Superior and middle conchae and posterior septum. V2 - Sphenopalatine ganglion --> Posterior superior dental nerve --> Gingiva, cheek, teeth, maxillary sinus mucosa.

Sinus Surgery

Caldwell-Luc

To achieve good anesthesia for this procedure, one needs to block the infraorbital nerve, the sphenopalatine ganglion, and the posterior superior dental nerve. The posterior superior dental nerve exits from the maxillary nerve adjacent to the sphenopalatine ganglion. To block the sphenopalatine ganglion and posterior superior dental nerve, introduce the local anesthesia through the greater palatine foramen via a curved needle.

Further topical anesthesia is applied with cocaine pledgets intranasally against the sphenopalatine ganglion. Local infiltration of the mucosa in the canine fossa will supply the hemostasis needed over the line of incision.

Ethmoid Sinuses

The sensory innervation of the ethmoid sinuses is intertwined with that of the nose and septum. In addition, it is innervated by the anterior ethmoid nerve (branch of the nasociliary, V1) and the posterior ethmoid nerve (branch of infratrochlear, V1).

Sphenoid Sinuses

The sensory innervation is from the pharyngeal branch of the maxillary nerve as well as the posterior ethmoid nerve.

General Anesthesia

Definition

General anesthesia is the chemically induced, reversible loss of conscious.

Mechanism of Action

The mechanism of action of general anesthetics remains a controversial issue. Most likely, these agents block multisynaptic neuronal pathways, such as in the reticular activating system of the brain stem. General anesthetics act on virtually all cell membranes and, therefore, affect all organs and systems.

14 General Anesthetics Agents

Inhalation Anesthetic Agents

These anesthetics are administered via an inhalation route and absorption occurs through the alveolar-pulmonary capillary interface.

1. Nitrous oxide is one of the oldest and remains one of the most useful of inhalation anesthetics. It usually is employed in an inspired concentration of 50-75% with oxygen. Nitrous oxide is a relatively safe but weak anesthetic agent.

2. Diethyl ether is among the older of the clinically useful general anesthetics and remains a relatively safe and useful agent. One of the major advantages of diethyl ether is the ventilatory stimulation which occurs at anesthetic stages. This is in marked contrast to the respiratory depression seen with virtually all other general anesthetics. This property makes diethyl ether a useful agent for bronchoscopic examination. The flammability hazard with diethyl ether has limited its use in recent years.

3. Cyclopropane is a potent anesthetic, commonly used in inhalation concentrations from 6-20%. Its usefulness is also limited by its flammability characteristics.

4. Halothane is an example of the series of halogenated hydrocarbons that have been synthesized and introduced into clinical practice during the recent 2 or 3 decades. It is a potent agent providing profound anesthesia when administered in concentrations of 1-2%. It is associated with cardiovascular and respiratory depression.

5. Methoxyflurane, Enflurane, and Isoflurane are additional members of the halogenated hydrocarbon family having many properties and complications similar to those of halothane. Methoxyflurane has been implicated in the production of a dose-related, high- output renal failure.

Intravenous Anesthetics

Thesxe anesthetics are administered via an intravenous route.

1. Thiopental is an ultrashort-acting thiobarbiturate. It has become one of the most widely used agents for the induction of anesthesia. Its use may be associated with profound cardiovascular and respiratory depression.

2. Ketamine is a newer intravenous anesthetic of the phencyclidine class of drugs. Ketamine induces a peculiar state, called dissociative anesthesia, in which patients are unresponsive to noxious stimuli but may appear to be awake with open eyes and spontaneous movement. Of significance, the pharyngeal and laryngeal reflexes remain intact until very deep levels of ketamine anesthesia are attained.

3. Innovar is a mixture of two drugs, droperidol (a major tranquilizer) and fentanyl (a potent narcotic). It acts much like other so-called "neuroleptic coctails" (morphine and

15 chlorpromazine, meperidine and diazepam) and usually is administered in combination with nitrous oxide and occasionally a short-acting barbiturate drug.

4. Butorphanol and Nalbuphine are examples of the narcotic-related drugs with mixed agonist-antagonist properties. These are being introduced into clinical practice because of their promise of providing potent analgesia with fewer of the undesired narcotic side effects (respiratory depression, addiction potential).

5. Diazepam is a major tranquilizer of the benzodiazepine family. In large intravenous doses in combination with an inhalation agent such as nitrous oxide it is useful for the induction and maintenance of general anesthesia.

Neuromuscular Blockers

Neuromuscular blocking agents act at the neuromuscular junction to induce a state of muscle paralysis. These are subclassified into the depolarizing agents (succinylcholine) and the nondepolarizing drugs (d-tubocurarine).

Complications

The discussion of the complications of general anesthetics will be confined to those of particular interest to otolaryngologists.

1. Aspiration pneumonitis may occur during general anesthesia as a consequence of the obtundation of laryngeal protective reflexes. Foreign matter which is permitted to accumulate in the pharynx (blood, gastric contents) will gain ready access to the pulmonary parenchyma. The result is the clinical syndrome of aspiration pneumonitis.

2. Cardiac arrhythmias: Most of the inhalation anesthetics are associated with a sensitization of the myocardium to catecholamines. In the presence of excess catecholamines, endogenously or exogenously produced, patients may develop ventricular arrhythmias and ventricular fibrillation. It is recommended that the exogenous administration of epinephrine be limited to a concentration of 1:100.000 and a total dose of 10 mL in any given 10 minute period when given in the presence of these anesthetics.

3. Hepatitis has been demonstrated to be a potential complication of virtually any anesthetic and surgical technique. A well publicized but poorly documented entity, so called "halothane hepatitis" has gained widespread notoriety. This type of hepatitis may be associated with an unusual metabolite of halothane to which certain sensitive individuals develop an allergic reaction. If this does exist as a unique entity it is extremely uncommon.

4. Malignant hyperpyrexia is a rare adverse reaction to anesthetics (occurring in approximately 1:15.000 anesthetic administrations). It is associated with a rapid rise in temperature to as high as 112°F and cardiovascular collapse and shock. Treatment consists of rapid termination of surgery and anesthesia, submersion of the patient into an ice bath, and general supportive measures. The mortality of this complication of anesthesia remains at greater than 50%.

16 5. Nitrous oxide-induced elevation in middle ear pressure: Because of its large blood solubility relative to nitrogen, nitrous oxide is well known for diffusing into closed gas spaces and producing an elevation in intraluminal pressures. In the case of tympanic surgery, diffusion of nitrous oxide into the middle ear may produce bulging of the tympanic graft. The distention is readily reversible if the nitrous oxide is discontinued and 100% oxygen is substituted.

17 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 26: Allergy and Immunology

Immunology

Immunity refers to the body's ability to resist a particular disease, infection, or poison. Immunology is the study of inherited and acquired mechanisms necessary to accomplish that goal.

The principal organs which serve as sites for proliferation and development of cells involved in immune responses are the thymus, spleen, lymph nodes, Peyer's patches of the gastrointestinal tract, and the bone marrow. The principal cells involved in the immune response are monocytes, neutrophils, eosinophils, lymphocytes, basophils, tissue macrophages, and mast cells.

The nonspecific immune response refers to phagocytosis plus inflammation with the production of various mediators whereas the specific immune response refers to the functions of the humoral (B cell) and the cellular (T cell) mediated systems.

Phagocytosis

Phagocytic cells migrate from capillaries to tissues to attack foreign invaders. The attraction to the proper area is chemotaxis. The offending microorganisms are then coated with opsonins, attached to phagocytes, ingested, killed, and digested.

1. The principal phagocytes are macrophages or monocytes, neutrophils, and eosinophils. Quantitative defects of neutrophils produce neutropenia which leads to recurrent infections. Hyposplenism causes a lack of macrophages which also makes one susceptible to serious infections.

2. Chemotaxis is the nonrandom movement of cells. There is a variety of chemotactic factors such as eosinophil chemotactic factor of anaphylaxis (ECF-A), products of clot formation, and lymphokines. The in vivo test for chemotaxis is the Rebuck skin window. An area of skin is scraped, the cover slip applied, and after a certain period the cover slip is stained and the cells which have migrated to the area are identified and counted.

3. Opsonins are serum factors which interact with microorganisms to aid their digestion by phagocytic cells. The two most important are IgG (heat-stable specific antibody) and complement C3b (heat-labile component).

4. Ingestion and intracellular killing: The opsonized microorganism is attached to and ingested by the phagocyte. The particle is incorporated into a vacuole into which granules containing lysozyme and other proteolytic enzymes are released. Demonstrable metabolic activity with increased oxygen and glucose consumption occurs. The increased glucose C1 oxidation affects hexose monophosphate activity. Intracellular killing is by means of high acidity, myeloperoxidase, or hydrogen peroxide. Some organisms are virulent because of their ability to destroy hydrogen peroxide.

1 5. Qualitative defect of phagocytosis implies a normal number of cells but abnormal function, i.e. chronic granulomatous disease of children. Enzyme defect creates a glucose-6- phosphate deficiency allowing recurrent infections by catalase-positive, peroxide-negative organisms such as E. coli, Klebsiella and Pseudomonas. The nitroblue tetrazolium test (NBT) is a good screening test of phagocytosis since a normally functioning phagocyte reduces this dye to an intense blue pigment.

Mediator Cells

This group of cells, mainly mast cells, basophils, and neutrophils, elaborate pharmacologically active substances that produce and control the inflammatory response. Primary mediators such as histamine are released early in the inflammatory response, whereas secondary mediators such as prostaglandins are released later. Examples of some of these mediators include the following.

Histamine

Histamine is a low-molecular-weight substance stored in the granules of circulating basophils and tissue-fixed mast cells. Histamine when released stimulates two distinct receptors. H1 receptors, inhibited by standard antihistamines, contract bronchial smooth muscle while H2 receptors, affected only by specific antihistamines, exist on stomach cells and stimulate gastric acid secretion.

Eosinophil Chemotactic Factor of Anaphylaxis (ECF-A)

This factor is a tetrapeptide with a molecular weight of about 500 that attracts eosinophils to the area of inflammation.

Slow Reacting Substance of Anaphylaxis (SRS-A)

This substance is an acid sulfur ester with a molecular weight less than 500. Like histamine, this is produced by mast cells and basophils. Although, initially, a greater percentage of histamine is produced, the ratio is reversed in a few minutes. Antihistamine block histamine but not SRS-A.

Kinins

Kinins act as secondary mediators of immediate hypersensitivity by causing contraction of bronchiolar smooth muscle, vasodilatation, and increased vascular permeability. The best known is bradykinin, a nine-amino acid peptide. Kinins are formed from kininogens in the presence of enzymes called kallikreins.

Prostaglandins

Prostaglandins are 20-carbon unsaturated aliphatic cells. These compounds potentiate the function of other mediators. Important in asthmatic patients.

2 Complement

Complements are the heat-labile portion of serum with bactericidal activity which are labeled in order of their discovery (i.e. C1, C2). Subunits or fragments are labeled with letters (i.e. C3a).

Activation

The classic complement pathway is activated by antigen-antibody complexes. Nine components are activated enzymatically in a cascadelike pattern. The alternative complement pathway can be activated by nonimmune means such as by the coagulation system.

Function

Their role is in host defense against infection, anaphylactic function, increasing vascular permeability, and chemotactic function atracting to the area of injury. Lytic function produces structural membrane damage. Component C3b acts as an opsonin to aid in ingestion by phagocytic cells.

Test of Complement Function

Complement function is tested by determination of the whole complement titer and measurement of the C3 level.

Clinical Findings

Deficiencies of the components of the complement cascade have been described. Clinical findings reveal a susceptibility to severe infections and autoimmune diseases. Hereditary angioneurotic edema (HANE) is due to the deficiency of a factor which controls the complement cascade C1-esterase inhibitor. Following light trauma there is an overproduction of CIE followed by anaphylatoxins which produce life-threatening edema.

Specific Antigen Recognition Cells

Lymphocytes have the ability to recognize very specific environmental materials called antigens and to produce a very specific response. Although all lymphocytes look alike under the microscope they are classified as T cells and B cells on the basis of very different functions; cell mediated immunity or humoral immunity.

T Lymphocyte Antigen Recognition System

These special lymphocytes named from their origin in the thymus gland comprise aboute 65% of the circulating lymphocytes and the cells of the subcortical regions of the lymph nodes. When special antigen receptors on the sensitized cell surface are triggered, morphologic changes such as mitosis and blast formation plus the release of lymphokines occurs. Some examples of lymphokines are macrophage inhibition factor (MIF), which inhibits outward migration of accumulated macrophages, and interferon, which protects cells against virus infection. T lymphocytes are responsible for delayed hypersensitivity skin

3 reactions, tumor immunity, transplant rejection, and immunity to facultative intracellular organisms (viruses).

Tests of T Cell Function

a. Lymphocyte count and morphology (remember 65% of peripheral lymphocytes are T cells).

b. E rosette assay: Human T lymphocytes spontaneously bind sheep red blood cells forming rosettes.

c. Delayed hypersensitivity skin tests: Positive delayed reactions of erythema and induration to previously encountered antigens.

d. Allogeneic skin graft rejection.

e. Special in vitro tests of lymphocyte proliferation and lymphokine production.

T Cell Deficiencies. Characteristic of T lympocyte disorders are recurrent infections by viruses, fungi, and mycobacteria. Live virus vaccination may lead to overwhelming infection. DiGeorge's syndroem, congenital aplasia of the thymus, is due to the failure of development of the third and fourth branchial pouches. Life-threatening infections are associated with hypoparathyroid disease.

B Lymphocyte Antigen Recognition System

The B lymphocytes differentiate in the bone marrow although the "B" stands for the bursa of Fabricius where these cells originate in the chicken. Antigen stimulated B lymphocytes proliferate or clone, migrate to the germinal centers of lymph nodes, mature into plasma cells, and when rechallenged form antigen specific humoral antibodies. The immunoglobulins (Ig) represent 20% of the plasma proteins (Table 26-1).

IgG. This is the major immunoglobulin in normal serum. It has a biologic half-life of 20-30 days, is located in intra- and extra-vascular spaces, functions as an opsonin, activates complement, neutralizes antigens, and is the only immunoglobulin transferred to the fetus. There are four subclasses (IgG1 through IgG4).

IgA. IgA is the second most abundant serum immunoglobulin. High concentrations occur in external secretions such as saliva, tears, and colostrum. Though synthesized as a monomer, IgA is secreted by the plasma cell as a dymer linked by a J chain. When in conjunction with the epithelial cell the secretory component is added. Two subclasses exist (IgA1 and IgA2).

IgM. With a molecular weight of 900.000, the largest immunoglobulin remains in the intravascular space. IgM is the earliest detectable immunoglobulin in the fetus, agglutinates particulate antigens, and activates complement.

4 IgD. Its function is unknown, but it is possibly the antigen receptor on lymphocyte surfaces.

IgE. This skin-sensitizing antibody is present only in trace amounts but is elevated in allergic and parasitic states (Table 26-2). IgE is produced by plasma cells in the paragut and pararespiratory lymphoid tissue and affixes to membrane receptors on basophils and mast cells. There is a very short serum half-life of 2.7 days but a much longer tissue half-life of about 15 days. Passively transferred IgE takes a minimum of 4 hours to attach to the basophils and mast cells. What happens next will be presented under the Allergy Type I anaphylactic reaction.

Molecular Structure of Immunoglobulins (Fig. 26-1)

Table 26-1. The Five Classes of Human Immunoglobulins

IgG IgA IgM IgD IgE

Molecular weight 150.000 160.000 900.000 150.000 190.000 Serum concentration 1240 280 120 3 0.03 (mg/100 mL) Subsets 42000 Placental transfer + ---- First detectable Ab - - + - - Comp activation + ---- Riagenic activity ----+ Half-life in days 21 6632.

Two identical heavy (H) chains and two identical light (L) chains are held together by noncovalent forces and covalent disulfide bridges. The L chains have the same molecular weight (MW) of 22.500, whereas the H chain MW varies from 53.000-70.000. The H chain determines the class and subclass of immunoglobulin. The IgM immunoglobulin is a pentamer (H2L2)5 formed by the covalent association of five subunits each having a molecular weight of 180.000. Fab fragment refers to the fragment of the antibody molecule that is antigen binding. At the opposite end is the crystallizable or Fc portion with no antigen-binding activity. Proteolytic cleavage of immunoglobulins with enzymes such as papain or pepsin is what produces these fragments. The hinge region which joins the Fab arms to the Fc region contains cysteinyl residues and allows for flexibility and change of configuration from a T to Y shape.

Tests of B Cell Function

1. Measurement of serum levels of immunoglobulins by radial immunodiffusion techniques for IgG, IgA, and IgM. Serum IgE assay requires the paper radioimmunoassay test (PRIST). 2. Measurement of natural specific antibodies such as isohemagglutinins. 3. Antibody response following immunization, Schick test. 4. Presence of plasma cells.

5 Table 26-2. Some of the Conditions Associated with Raised Levels of Total Serum IgE

Atopic Allergic Diseases

Atopic rhinitis Atopic asthma Atopic dermatitis

Other Hypersensitivity Disorders

PIE syndrome Bronchopulmonary aspergillosis Wiskott-Aldrich syndrome

Parasitic Infestations

Visceral larva migrans (Toxocara canis) Intestinal capillariasis (Capillaria philippinensis) Schistosomiasis Ascariosis Hookworm Echinococcosis Trichinosis Topical eosinophilia (filariasis)

Immunologic Deficiencies or Disorders

Thymic dysplasias or deficiencies (T-lymphocyte disorders) Hyperimmunoglobulinemia E with recurrent pyodermas (Job-Buckley syndr)

Miscellaneous Conditions

Leprosy Pemphigoid Pulmonary hemosiderosis (occasionally) Multiple myeloma Autoimmune diseases (occasionally) Minimal-change nephrotic syndrome (occasionally).

Disorders Affecting B Cells

Chronic or recurrent pyogenic infections with virulent extracellular bacteria such as gram-negative cocci and Haemophilus influenzae are characteristic of B cell deficiencies. Since antibodies, complement, and phagocytes work together to immobilize and destroy pathogenic organisms, the clinical manifestations of B-cell deficiencies, complement deficiencies, and phagocyte abnormalities are similar. Chronic sinopulmonary disease is common.

6 Hypogammaglobulinemia can be hereditary, transient in infancy, or acquired later in life secondary to a metabolic problem, immunosuppressive agents, surgery, or systemic disease. The most common specific dysgammaglobulinemia is selective IgA deficiency.

Regulation of the immune response. What determines the degree of response or of antibody production?

1. The antigen is the first factor. A larger antigen that is aggregated or particulate produces a greater response.

2. The T cells release lymphokines which may help or suppress the immune response (antibody production. These therefore are called T cell helpers or T cell suppressors.

3. Levels of the nucleotides, cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), reflect the energy function of the principal cells involved in the immune response. Cyclic AMP is the activator of phosphorylase kinase which is important in glucose release. Increasing cytoplasmic concentration of cAMP modifies cell membrane permeability and inhibits the release of mediators. Lowering of the intracellular cAMP causes the release of mediators of anaphylaxis which then produce the pathological response.

Allergy

Allergy is defined as a hypersensitive or pathologic reaction to environmental factors or substance such as pollens, foods, dust, or microorganisms in amounts that do not affect most people. Allergy involves the release of mediators from mast cells and basophils triggered by a variety of agents and subdivided into atopic (IgE mediated) and nonatopic (non-IgE mediated)(Fig. 26-2). At least 10% of the population has some allergy-related disorder.

Historical Background

1. John Bostock 1819: Earliest description of "summer catarrh". 2. Blakeley, 1873: First skin tests for grass sensitivity. 3. Von Pirquet, 1906: Introduced the term "allergy". 4. Noon, 1911: First desensitization with pollen extract injection. 5. Prausnitz-Küstner, 1921: Passive transfer of skin sensitizing factor in serum. 6. Cooke, 1935: Blocking or inhibiting antibody in serum treated patients. 7. Rinkel, 1963: End-point intracutaneous titration (optimal dose). 8. Porter, 1959: Anatomy and functional structure of immunoglobulins. 9. Berson and Yalow, 1959: Development of radioimmunoassay techniques. 10. Wide, 1968: Assay for specific IgE antibody (RAST).

7 Classification of Hypersensitivity Reactions into Four Types as Described by Gell and Coombs (Table 26-3)

Table 26-3. Gell and Coombs Classification of Hypersensitivity Reactions

I or Anaphylactic

Allergic rhinitis and conjunctivitis Extrinsic asthma Urticaria and angioedema (some) Anaphylaxis (some) Allergic bronchopulmonary aspergillosis (type III also) Atopic eczema (?) Drug reactions Insect hypersensitivity.

II or Cytotoxic

&& Blood transfusion reaction (anaphylaxis) & Hemolytic disease of the newborn && Isoallergic neonatal thrombocytopenia && Coombs positive hemolytic anemias && Drug-induced decreases in circulating blood cells (RBCs, WBCs, platelets) Goodpasture's disease

III or Immune Complex or Arthus Type

Serum sickness Lupus erythematosus Glomerulonephritis (i.e. poststreptococcal) Allergic bronchopulmonary aspergillosis (type I also) Hypersensitivity pneumonitis (type IV also) Vasculitis Drug reactions

IV or Delayed Hypersensitivity

Contact dermatitis Experimental allergic encephalitis Tuberculin sensitivity Tissue transplant rejection Drug reactions Hypersensitivity pneumonitis (type III also).

& Does not involve complement. && May or may not involve complement.

8 Type I Anaphylactic Reaction

The immediate type of hypersensitivity reaction occurs in about 10 minutes on introduction of an antigen into a sensitized person. This is the humoral or reaginic response. IgE antibodies attach to the membranes of mast cells and basophils, as many as 80.000 IgE molecules per cell. When two juxtaposed antigen-specific IgE molecules are attached to Fc receptors and bridged by the appropriate antigen, a series of cell surface events occurs causing the release of the vasoactive amines, primarily histamine. Relatively few specific IgE molecules thus can produce a devastatingly amplified response. Clinically this reaction is found in bronchial asthma, allergic rhinitis, urticaria, some food and drug allergies, and reactions to stinging insects.

Type II Cytotoxic Reaction

This complement-dependent reaction is slower and takes a few hours to occur. The antigen attaches to a target cell which dies in the presence of antibody and fresh complement, the complement-fixing antibody being directed against cell membranes. One can have transfusion reactions due to antibody acting with red cells, white cells, or platelets. Clinical examples are the autoimmune hemolytic anemias, poststreptococcal glomerulonephritis, and the hemolytic anemias.

Type III Toxic-Complex Reactions

Consider an antigen uniting with a circulating antibody to form a "solubable complex" or "immune complex". This type of hypersensitivity, which may take 6 hours to develop, refers to the antibody aggregates which attach to the endothelial cells of small blood vessels. An inflammatory reaction follows the realease of mediators. Clinically, we have the Arthus reaction, a local response, or serum sickness, a generalized response.

Type IV Cellular Hypersensitivity

This reaction occurs 24-72 hours after antigen introduction with no mediation by the conventional circulating antibodies. Instead the antigen acts directly with the sensitized T lymphocyte which releases SRS, kinins, and proteolytic enzymes. Examples are tubercle formation and homograft rejection.

Some Common Antigens of Allergic Importance

Pollens

Pollen grains common to all flowering plants develop in the anther or the stamen. The outermost layer, the exine is quite rigid. Within is the intine composed of cellulose which enclose the protoplast. Thommen postulated that for pollen to be symptomatic it must be allergenic, be anemophilous or windborne, sufficiently buoyant to be transported long distances and widely distributed in the ambient air.

9 Fungi

Fungi have nonchlorophyl, branching, filamentous hyphae which generally reproduce by spore formation. The airborne spores are the major source of inhalant exposure. Fungi recovered indoors include Penicillium, Aspergillus, and Fusarium. The most common outdoor fungi are Alternaria, Heminthosporium, and Hormodendrum.

House Dust

A heterogenous mixture of human and animal danders, fungi, bacteria, insect debris, vegetable and wood fibers, foor remnants, and inorganic substrates. The mite content of house dust may be the most important antigen but the degeneration of vegetable matter particularly cotton linters is also important.

Other Nonpollen Allergens

Consider feathers, especially old decaying ones, seeds such as cottonseed found in cotton linters and flaxseed, orris root, the powdered root of the iris family, and pyrethrum found in insecticides. Symptoms caused by tobacco may be the nonspecific irritation from smoke, a specific allergy to tobacco smoke, allergy to tobacco itself, the flavoring materials such as perfumes and oils, or to tobacco dust and associated molds.

Contact Allergens

Allergic contact dermatitis is a type IV cell-mediated delayed hypersensitivity. Contact chemicals may act as haptens combining with epidermal protein to form a complete antigen- inducing sensitization. Repeat contact induces the inflammatory reaction. The most common sensitizers are Rhus sp. or poison ivy, paraphenylenediamine used in industry, nickel compounds, rubber compounds, ethylenediamine used in medications, and dichromates used in ink and paints.

Common Food Allergens

The most common foods associated with a type I anaphylactic response are fish, eggs, nuts, and cow's milk. Type III antigen-antibody complexes produce serum sickness or an Arthus reaction. Milk precipitins have been identified. A type V reaction was recently postulated to explain the oddities of many food allergies; their cyclic nature, masking effects, and additive effects that are not explained by the Gell and Coomb Classification I-IV.

Food allergens are usually glycoproteins with a molecular weight between 18.000 and 36.000. Foods also may contain pharmacologically active substances such as vasoactive amines in bananas, cheese, and wines, and methylxanthines such as caffeine found in coffee, tea, and colas.

10 Salicylates

This ubiquitous medicine will occasionally produce a watery nose with obstruction and polyp formation, asthma, urticaria, plus a high eosinophil count. However, this is not IgE- mediated since there is no skin sensitivity and no passive transfer.

Salicylates may inhibit endogenous prostaglanding production causing an imbalance.

The Allergy Workup and Additional Tests

Nasal Cytogram

1. Allergy: Increased eosinophils and goblet cells plus enlarged irregular lymphoctes. 2. Bacterial infection: Increased polys and bacteria. 3. Viral infection: Exfoliated cells with granulation and fragmentation of the cytoplasm, pyknotic nuclei, and inclusion bodies.

RAST (Table 26-4)

Table 26-4. Indications and Contraindications for Use of RAST

Indicated

In patients not responding to environmental control and conservativew medical management. In apprehensive children and infants in whom atopic sensitization seems likely. In symptomatic patients with conditions in which in vivo skin testing is contraindicated (dermatographism, eczema, etc.). In patients unable to stop medication adversely affecting skin testing. In patients doing poorly on immunotherapy. In evaluating individual sensitivities when initiating specific immunotherapy in atopid patients. In transfer allergic patients on immunotherapy. In venom sensitivity. In the diagnosis of IgE-mediated food sensitivity.

Contraindicated

In patients with positive histories of sensitivity in whom nonspecific therapy is effective in alleviating symptoms. In asymptomatic atopic patients currently on immunotherapy. In symptomatic patients with negative skin tests.& In patients with total IgE levels below 10 U/mL. In the diagnosis of non-IgE-mediated disorders.

& Properly performed at adequate concentrations with potent extracts.

11 This test is a unique way of measuring the IgE response to an individual antigen. There are three steps to this assay:

1. Antigen is coupled to solid phase material such as a cellulose paper disc. 2. Specific IgE antibody can react and bind to the immobilized antigens. 3. The above molecule is now the antigen for radioactive labeled antibody specific to IgE.

Skin Tests

An in vivo bioassay challenges specific IgE-sensitized mast cells in the skin. Variables are the potency and purity of the extracts, skin reactivity, age, site of application, and prior medications. Scratch and prick tests are less sensitive than intradermal tests. Serial dilution titration is an intradermal method that uses 1:5 serial dilutions of the allergen for a more accurate response.

Treatment of Allergic Problems

Although environmental control and food management play a major role in the treatment of allergic problems I have limited this chapter to the pharmacologic and immunologic approach.

Sympathomimetics

Sympathomimetics or adrenergics are classified into alpha or beta depending on their action, excitatory or inhibitory, on target organs. If we know the activity of a particular adrenergic agent we can predict its actions.

Alpha Receptors

Excitatory action constricting the vascular smooth muscles especially of the skin and mucous membranes. This action raises blood pressure, reduces edema, help hemostasis. Action on viscera is inhibitory.

Beta Receptors

Inhibitory except for the heart which is excitatory. Further classification into beta-1 and beta-2.

Beta-1 Receptors

In the heart and small intestine.

Beta-2 Receptors

In the bronchi, blood vessels and uterus.

12 Alpha-adrenergic agents such as phenylephrine are potent vasoconstrictors. They have no therapeutic use for asthma, but are used most often as topical or oral decongestants for the nose and eyes.

Beta-2 receptors in the bronchi are of importance for the treatment of asthma. Stimulation of the beta receptors leads to activation of adenylcyclase and an increase in cAMP. Isoproterenol is a beta-2 receptor stimulator (beta agonist) that has some beta-1 stimulation of the heart causing side effects of tachycardia, palpitations, and hypertension. Terbutaline and metaproterenol are newer beta-2 agonists with less beta-1 activity that can be given orally or by inhalation.

Epinephrine with both alpha and beta activity is the sympathomimetic of choice in an acute anaphylactic reaction. Alpha activity causes vasoconstriction with elevation of blood pressure, beta-1 activity increases heart rate and output and beta-2 activity dilates the bronchioles.

Antihistamines

Once the structure and function of histamine in inflammation and allergy was determined along came a group of compounds with a core of ethylamine (CH2-CH2N+) which competes with a similar core on the histamine molecule. Thus antihistamines block histamine at the H1 receptor site, they do not block histamine production or destroy liberated histamine.

Ethylamine Core (CH2-CH2N=X)

Six Families X= Example

Ethanolamines Oxygen link Diphenhydramine Alkylamines Carbon link Chlorpheniramine Ethylendiamines Nitrogen link Tripelenamine Piperazines Piperazine link Hydroxyzine Phenothiazines Phenothiazine Promethazine Miscellaneous Clemastine.

Antihistamines are of value in the treatment of urticaria, anaphylaxis, allergic angioedema, pruritus, rhinitis, and the common cold. Adverse reactions are diverse and include sedation, dizziness, nervousness, anorexia, dryness of mouth, and hypotension.

Heparin

When dealing with an acute anaphylactic emergency type I such as acute asthma or angioneurotic edema that is not responding to epinephrine and antihistamines it is worthwhile having heparin in your armamentarium.

An acid polysaccharide, heparin combines with alkaline histamine to form a neutral salt. In fact, histamine is naturally stored in the mast cell granules as a heparin-histamine salt. Heparin also may inhibit the early stages of the complement cascade. Apparently heparin does

13 not neutralize the effect of slower-acting serotonin or the kinins and therefore is only effective very early in an allergic emergency.

Cromolyn

Cromolyn acts directly on mast cells and basophils in same manner to prevent degranulation and release of mediator histamine and SRS in atopy and anaphylaxis. Cromolyn stabilizes the mast cell membrane. Available as a powder administered by a "spinhaler", cromolyn is of value in preventing an asthmatic attach but is of no use once an attach has begun.

Corticosteroids

These drugs, so useful in medicine, have the ability to control inflammation temporarily and therefore have an important role in immunology and allergy. The exact mode of action is unknown but the following beneficial effects occur.

1. Affect the sodium and potassium pump reducing water uptake and edema. 2. Reduction of capillary permeability. 3. Stabilization of lysosomal membranes preventing release of mediators. 4. Possibly augment adrenergic stimulation of adenylcyclase increasing cAMP.

Unfortunately there are several complications to consider when prescribing corticosteroids for any length of time, including sodium retention and potassium loss, creating fluid and electrolyte imbalance, gastrointestinal irritation, muscle weakness, osteoporosis, growth suppression, adrenal suppression, diabetes, glaucome, cataracts, and increased susceptibility to infection.

The steroids dexamethasone, beclomethasone, and flunisolide have been developed as aerosol medications for asthma or rhinitis therapy. There is an active topical effect to control local symptoms of allergy without the usual systemic effects mentioned above.

Theophylline

The methylxanthines, of which theophylline is the most important, are competitive inhibitors of phosphodiesterase that catalyzes the conversion of cAMP to inactive 5-AMP. Since methylxanthines prevent the destruction of cAMP while the beta agonists (i.e. metaproterenol) increase cAMP production via the enzyme adenylcyclase, there is a complementary effect when used together.

To relax bronchial smooth muscle by the above means the theophylline serum level must reach 10-20 microg/mL. Toxic effects to consider are central nervous system and cardiovascular stimulation, gastrointestinal irritation, renal albuminuria and hematuria, and diuresis causing dehydration.

14 Immunotherapy

Although there has been controversy over the efficacy of immunotherapy there is mounting evidence that a number of beneficial immune changes do occur.

1. Increase of IgG blocking antibodies in the serum. 2. Stimulation of IgA- and IgG-blocking antibodies in secretions. 3. Suppression of antigen-specific IgE antibodies. 4. Decrease in proliferative response of T cells.

Immunotherapy should be considered an adjunct to total allergic management that can help control but not cure symptoms (Table 26-5). In the future we may be dealing with allergoids (formalin-modified antigens); urea-denatured antigens, or polymerized antigens now being designed to reduce their allergenic properties while stimulating protective antibodies.

Table 26-5. Indications and Contraindications for Immunotherapy

Indications

Symptoms initiated by IgE antibodies. Respiratory allergy: perennial nasal allergy, seasonal hay fever, bronchial asthma. Severe symptoms - not controlled by mediaations and avoidance. Long seasons. Multiple seasons. Perennial symptoms.

Complications:

Recurrent infections. Serous otitis media or hearing loss. Asthma. Increased morbidity. Increased absenteeism. Decreased quality of life. Intolerance to antiallergic drugs.

Contraindications

Nonimmune mechanisms responsible for symptoms.

IgE-mediated mechanism: Mild symptoms - readily controlled by simple methods. Easily avoidable allergen. Atopic dermatitis. Gastrointestinal food allergies. Very short seasons. Noncompliant patients. Food allergy.

15 Relative Contraindications:

Infants and children under 2 years of age. IgE-mediated drug and chemical sensitivity.

16 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 27: Immunology

Immunology is the study of the body's response to foreign substances.

An antigen is a substance which elicits a specific immune response, either production of antibody and/or activation of lymphocytes. Antigens are either proteins of high-molecular- weight carbohydrates. External antigens include microorganisms and pollen, while alloantigens are genetic, such as blood group (ABO and Rh) and tissue typing (histocompatibility) antigens.

An adjuvant is a substance that when mixed with an antigen will augment the immune response.

An antigenic determinant is the part of an antigen that induces the immune response.

A hapten is an nonantigenic substance that, when linked to carrier molecules, produces an immune response.

Components of the Immune Response

The major components of the immune response are lymphocytes, lymphokines, antibodies, macrophages, passively triggered cells, and nonspecific mediators such as complement and histamine (Fig. 27-1).

Figure 27-1. Components of the Immune Response

Bone Marrow Stem Cells Thymus Processing T Lymphocytes + Antigen Sensitized T Cell

Memory cells Lymphokine-producing cells Lymphokines Activated macrophage (antigen, complement, antibody) Delayed hypersensitivity cells Cell-mediated immunity Killer cells Cytotoxic reactions Suppressor cells Helper cells

1 Gut associated lymphoid tissue B Lymphocytes + Antigen Sensitized B cell

Lymphoblast Plasma cell Antibody Memory cells

Null Lymphocytes + Antigen

Killer Cells

Cytotoxic Reaction

Lymphocytes

T lymphocytes are thymus influenced and compose 80% of the circulating lymphocytes. These cells are responsible for cell-mediated immune reactions, are inactivated by antilymphocyte serum, and usually are identified by rosette formation with sheep red blood cells. Subpopulations of T cells include:

1. Delayed hypersensitivity cells which are responsible for cell-mediated immune reactions. 2. Lymphokine producers which manufacture lymphokines, substances that influence effector macrophages. 3. Suppressor cells which retard antibody formation. 4. Helper cells which enhance B cell antibody production. 5. Killer cells which are cytotoxic to tumor cells and transplanted tissues.

B lymphocytes are derived from gut-associated lymphoid tissue and mature into plasma cells, the most important source of antibody. They compose 20% of circulating lymphocytes, contain surface immunoglobulin, and usually are identified by immunofluorescence with antiimmunoglobulin.

Null lymphocytes lack markers of both T and B cells and probably function as killer cells.

2 Lymphokines

These substances are soluble glycoproteins produced by sensitized T and B cells and have a molecular weight of 30.000-100.000:

1. Migration-inhibition factor (MIF). 2. Macrophage-aggregating factor (MAF). 3. Skin-reactive factor. 4. Cloning inhibitory factor. 5. Lymphotoxin.

6. Leukocyte inhibitory factor (LIF). 7. Chemotactic factor. 8. Blastogenic factor. 9. Interferon. 10. Lymph node permeability factor. 11. Transfer factor (TF).

Of clinical importance are: (1) interferon which is produced locally in response to viral and parasitic infections and which renders transient protection against viral infections. Interferon also is being tested as an antitumor agent; (2) transfer factor which is useful for treatment of mucocutaneous candidiasis.

Antibodies

Antibodies are immunoglobulins that can react with the specific antigen that stimulated their production. Immunoglobulin molecules are all composed of light (small) and heavy (large) polypeptide chains consisting of a constant carboxyl terminal portion and a variable amino terminal portion (Fig. 27-2). Papain cleavage of an IgG molecules produces two Fab fragments which bind antibody and one Fc fragment which fixes complement and binds to cell membranes.

There are two types of light chains, kappa and lambda, present in all types of immunoglobulins. Each of the five types of immunoglobulins has a distinct class of heavy chain. Properties of the five types of immunoglobulins are listed in Table 27-1.

Homogenous light chains (either kappa or lambda) are secreted in the urine as Bence Jones proteins in multiple myeloma. Light chains also are found in the amyloid of primary amyloidosis.

Waldenström's macroglobulinemia is associated with IgM immunoproliferations.

Heavy chain fragments are found in the urine and serum of individuals with heavy chain disease.

3 Table 27-1. Immunoglobulins

IgG IgM IgA IgE IgD

Sedimentation cons 7S 19S 7S (serum) 8S 7S 11S (secretions) Molecular weight 150.000 900.000 170.000 (se) 190.000 180.000 400.000 (secretions) Serum concentration 1000-1500 60-180 100-400 0.03 3-5 (mg/100 mL) Heavy chain class gamma mi alpha epsilon delta Fixes complement Yes Yes No No No Crosses placenta Yes No No No No Comments Major Ab Early Ab Main Ab Reagin Ab late Ab response in secret in allergy. response

Macrophages

Macrophages and their circulating form, monocytes, constitute the mononuclear phagocytic system formerly called the reticuloendothelial system. These cells have an active role in the immune response. They process antigen for T and B cell recognition and they are activated by lymphokines and lymphocytes to enhance their phagocytic and digestive capacity.

Complement

The complement system is a complex system of 11 major proteins naturally occurring in serum which helps mediate immune and inflammatory reactions. This system can be activated by antigen-antibody complexes (classic pathway), or by a variety of substances such as bacterial lipopolysaccharides (properdin or alternative pathway). The major functions of complement are: (1) immune adherence (C3b); (2) anaphylatoxin production (C3a, C5); (3) chemotactic (C3a, C5a, C5b,6, 7); (4) lysis (C6,7,8,9).

Hereditary angioneurotic edema is an hereditary deficiency (autosomal dominant) of C1-esterase inhibitor resulting in episodes of increased C1 activity, particularly following trauma.

Consumption of C2 and C4 occurs resulting in release of a vasoactive kinin responsible for the edema. Life-threatening laryngoedema can result. Severe gastrointestinal pain is common. This condition does not respond to epinephrine or corticosteroids and should be prevented with epsilon-aminocaproic acid or danazol.

Passive-cells include neutrophils, eosinophils, and basophils. Neutrophils are the major phagocytes in the circulation and clear antibody-coated microbes from blood and tissue.

Eosinophils and basophils are important in type I hypersensitivity reactions. IgE antibody can fix to these cells and cause release of mediators of anaphylaxis.

4 Hypersensitivity Diseases

There are four basic mechanisms of immunologic injury (Table 27-2).

Table 27-2. Immune Tissue Injury

Type I Type II Type III Type IV Anaphylactic Cytotoxic Imune Delayed Atopic Complex Hypersens

Immunogl IgE IgG IgG, IgM None Complement No Yes Yes No mediated Mechanism Mast cell Complement Immune complex T cell degranulation cytolysis deposition lymphokine release Examples Anaphylaxis Transfusion Serum sickness Contact Rhinitis Rh reaction Poststrep GN dermatitis Asthma Tuberculin.

Type I

Anaphylaxis or immediate hypersensitivity is usually mediated by IgE antibody which fixes to mast cell membranes and, in the presence of antigen, causes degranulation of the cell and release of mediators (Fig. 27-3). Intracellularly, the IgE activated membrane results in flow of calcium ions and microtubule aggregation. There is a decrease in the ratio of intracellular cyclic AMP to cyclic GMP. Agents capable of increasing cAMP inhibit histamine release.

Type I reactions cause anaphylaxis and allergic reactions to foods, drugs, pollens, and other inhalants, as well as allergic asthma and sinusitis. Atopic individuals have a genetic predisposition to form IgE-type reactions and comprise 15-20% of the population.

The mediators released by type I reactions are:

1. Histamine, which increases vascular permeability, causing tissue edema, and which causes contraction of smooth muscle resulting in pain and itching. 2. Slow-reacting substance of anaphylaxis (SRS-A), which causes smooth muscle contraction and bronchial asthma. 3. Eosinophilic chemotactic factor of anaphylaxis (ECF-A), which causes local accumulation of eosinophils. 4. Serotonin, which acts in a similar manner to histamine. 5. Bradykinin, which causes prolonged smooth muscle contraction as well as vasodilatation. 6. Platelet aggregation factor (PAF), which aggregates platelets and causes them to release vasoactive amines. 7. Prostaglandins F and A, whose role is uncertain. 8. Anaphylatoxins, which cause histamine release from mast cells.

5 Modulators of type I reactions:

1. Atropine blocks formation of cGMP. 2. Methylxanthines prevent cAMP destruction. 3. Corticosteroids inhibit histamine formation and stabilize cell membranes preventing mediator release. 4. Catecholamines block alpha and beta receptors to permit accumulation of cAMP. 5. Antihistamines block histamin receptors on nerve endings. 6. Cromolyn sodium stabilizes cell membranes and prevents calcium influx.

Type II

Cytotoxic reaction occurs when IgG or IgM antibody reacts with antigens on cell surface membranes leading to cell lysis or damage. The Fab end of the antibody fixes to either natural or foreign antigen of the cell surface while the Fc end combines with either a monocyte or with complement to cause cell damage. Examples of type II injury are hemolytic anemia and immune leukopenia and thrombocytopenia.

Type III

Immune complex-mediated injury occurs when IgG or IgM antibody forms soluble complexes with antigen and settles out in endothelial surfaces of blood vessels, glomeruli, and synovium. Examples of type III injury are the Arthus reaction, serum sickness, and poststreptococcal glomerulonephritis.

Type IV

Cell-mediated injury occurs when sensitized T lymphocytes react with antigen and release lymphokines. Contact dermatitis is an example of type III reaction as is the tuberculin skin test.

Clinical Allergy

The most common allergic problems seen in ENT practice are allergic sinusitis, rhinitis, and bronchial asthma. Seasonal symptoms usually are related to pollens or mold spores while perennial symptoms usually are due to house dust, animal dander, and household molds. In the Northeast and Midwest tree and grass pollens are present in the spring, and ragweed, the mold spores of Alternaria and Hormodendrum are present in the late summer and fall. Proteins of the house mite are the main antigen in house dust. Aspergillus and Penicillium are the most common household molds. Food allergies are probably also of importance, but scientific documentation of this point is not available. There is no evidence to support the notion of allergy to an individual's "own" bacteria or fungal flora.

Allergy Evaluation

Careful history of a patient's symptoms and the correlation with potential allergens is essential. Seasonal symptoms, frequent sneezing, coexistent conjunctivitis, family history of atopy, eczema, and copious watery nasal discharge are all suggestive of allergy.

6 Skin Testing and Other Tests

1. Intradermal testing with aqueous extract of antigen is the best method of substantiating a clinical diagnosis of allergy. Systemic reactions may occur with this method. 2. The scratch test and prick test are not as sensitive as the intradermal test, but often are used to define highly allergic individuals to prevent systemic reactions. 3. Conjunctival testing is very sensitive, but of limited clinical value. 4. The RAST test (radioallergosorbent) measures antigen-specific antigen in the serum and correlates well with intradermnal testing. It is of value for those patients who cannot undergo skin testing. 5. The RIST test (radioimmunosorbent) produces similar results. 6. Eosinophil count: Elevated blood eosinophil count or demonstration of eosinophils in nasal secretions suggest allergy. 7. Patch testing is used for diagnosis of contact dermatitis. Antigen is placed in contact with the skin for 24-48 hours to produce local dermatitis. 8. Pulmonary functions tests accurately quantitate airway resistance and subclinical bronchospasm. Challenge with inhaled allergen is sometimes useful to diagnose allergic asthma. 9. Elimination diets are the only reliable way of diagnosing food allergy. Food groups such as dairy products, wheat, and yeast, may be eliminated on a trial basis with close observation of symptomatic changes. 10. Venom skin testing for stinging insect hypersensitivity is accurate, but must be done with extreme caution.

Of no proven value are provocative testing by the intracutaneous or the sublingual route or the titration method of Rinkle for determining the optimum dose of immunotherapy.

Immunotherapy

Subcutaneous injections of aqueous or alum-precipitated allergen in a schedule of gradually increasing amounts until a maintenance dose is achieved has proved of value in the treatment of pollen and dust allergy. This method of biweekly or monthly perennial treatment is called immunotherapy. High concentrations of extract to achieve a total preseasonal antigen immunization (>25.000 protein nitrogen units (PNU)) is required. Blocking IgG antibody is produced which competitively binds antigen to prevent binding to IgE and subsequent mediator release. Moreover, IgE production is decreased resulting in lower serum levels.

Immunotherapy with stinging insect venom is effective as opposed to treatment with whole body extract. This procedure must be done with caution.

Of no proven value are the Rinkle method of titrated injection, sublingual therapy, or bacterial vaccine injection.

7 Immunodeficiency Diseases

T Lymphocyte Deficiencies

DiGeorge's Syndrome or Thymic Hypoplasia

This disease is not genetic, but is due to abnormal embryogenesis of third and fourth pharyngeal pouches resulting in hypoplasia of thymus and parathyroids. Neonatal tetany, unusual facies, increased infections, and abnormal delayed hypersensitivity with normal immunoglobulins are characteristic.

Nezelof's Syndrome

This syndrome is an autosomal-recessive thymic hypoplasia with an isolated T cell defect, normal immunoglobulins, and susceptibility to fungal and Pneumocystis carinii infection.

Partial T Cell Loss

Mucocutaneous candidiasis is the most common example. Isolated T cell deficiency with no delayed hypersensitivity to Candida causes recurrent infection of mucous membranes and nail beds. Transfer factor is the treatment of choice.

B Lymphocyte Deficiency

Transient Hypogammaglobulinemia of Infancy

A normal infant is born with 90% of normal IgG and no IgM or IgA. The IgG level falls for the first 3 months of life. The condition is self-correcting.

Congenital Agammaglobulinemia

Sex-Linked (Bruton Type). This type affects boys only. All immunoglobulins are low and there are frequent bacterial infections. The T cells are normal. Treatment is with gammaglobulin.

Dysgammaglobulinemia. There is a selective absence of one class of immunoglobulin. IgA absence if the most common (1:1000 individuals). It is due to increased T suppressor cells and failure of B cell maturation. It is not sex-linked. IgA deficiency is associated with autoimmune diseases and some malignancies.

Acquired Agammaglobulinemia

This is often associated with malignancies of the reticuloendothelial system such as lymphoma and multiple myeloma.

8 Combined Immunodeficiency Disease

Sex-Linked Agammaglobulinemia

Boys only are affected with a variable degree of agammaglobulinemia. There is both T and B cell dysfunction, with a 2-year life expectancy.

Autosomal Recessive (Swiss Type)

Both sexes are affected. Viral, fungal, and bacterial infections are due to a severe T and B cell defect. Lymphopenia and hypoglobulinemia are characteristic.

Wiskott-Aldrich Syndrome

This syndrome is X-linked with eczema, thrombocytopenia, and infections. There is a low IgM level. Transfer factor and bone marrow transplantation are sometimes helpful.

Immunodeficiency with Ataxia-Telangiectasia

This is autosomal recessive with a variable pattern. IgA and IgE deficiencies are most common with a decreased T cell function. These patients develop progressive neurologic involvement.

9 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 28: The Chest

Pulmonary Volumes and Capacities

Tidal volume (TV) = depth of breathing = volume of gas inspired or expired during each normal respiratory cycle = 0.5 L on the average.

Inspired reserve volume (IRV) = maximum volume that can be inspired from end- inspiratory position = 3.3 L on the average.

Expired reserve volume (ERV) = maximum volume that can be expired from end- respiratory level = 0.7-1 L on the average.

Residual volume (RV) = volume left in lungs after maximum expiration = 1.1 L on the average.

Forced expiratory volume in 1 second = FEV1 (FEV1 should be 80% or more of predicted value from a normative chart).

Forced vital capacity = FVC (FVC should be 80% or more of predicted value from a normative chart).

The ratio of FEV1/FVC should be greater than 0.75 for young patients and 0.70 for older individuals.

Total lung capacity (6 L for males; 4.2 L for females)

TLC=IRV+TV+ERV+RV

(Total volume contained in the lungs after maximum inspitation).

Vital capacity (4.8 L for males; 3.1 L for females)

VC= IRV + TV + ERV

(Maximum volume that can be expelled from the lungs by forceful effort following maximum inspiration).

Functional residual capacity (2.2 L for males; 1.8 L for females)

FRC=RV+ERV

(Volume in the lungs at resting expiratory level).

Physiological dead space (dead space of upper airway bypassed by tracheotomy 70-100 cc).

1 Physiological dead space = Anatomical dead space + the volume of gas that ventilates the alveoli that have no capillary blood flow + the volume of gas that ventilates the alveoli in excess of that required to arteriolize the capillary blood.

Mean Normal Blood Gas and Acid Base Values

Arterial Blood Mixed Venous Blood

pH 7.40 7.37

pCO2 41 mm Hg 46.5 mm Hg

pO2 95 mm Hg 40 mm Hg

O2 sat 97.1% 75.0%

bicarbonate 24. mEq/L 25.0 mEq/L

Miscellaneous

1. Silo-filler's diseae (bronchiolitis obliterans) is a pathologic entity consisting of a collection of exudate in the bronchioles, obliterating the lumen. This complication often follows inhalation of nitrogen dioxide, exposure to open bottles of nitric acid, and exposure to silos. The diagnosis is made on history of exposure, dyspnea, cough, and x-ray findings similar to miliary tuberculosis. Treatment is symptomatic. Prognosis is poor since the majority of these patients eventually succumb to this disease.

2. Bronchogenic cysts are congenital, arise from the bronchi, and are lined with epithelial cells. Furthermore, their walls may contain glands, smooth muscles, and cartilage. In the absence of infection they may remain asymptomatic. Otherwise, they give a productive cough, hemoptysis, and fever. The recommended treatment is surgical excision.

3. Blebs or bullae: These are air-containing structures resembling cysts but their walls are not epithelium lined.

4. Anthracosilicosis: Coal miner's pneumoconiosis.

5. Berylliosis: This condition is characterized by an infiltration of lungs by beryllium. It often is found in workers at fluorescent lamp factories.

6. Bagassosis: This condition is characterized by an infiltration of the lungs by sugar cane fibers.

7. Byssinosis: This condition is characterized by an infiltration of the lungs by cotton dust.

8. Adenocarcinoma of the bronchus is the leading primary pulmonary carcinoma in females while bronchogenic (squamous cell) is most common in males.

2 9. Pancoast syndrome (superior sulcus tumor) is a syndrome caused by any process of the apex of the lung which can invade the pleural layers, infiltrate between the lower cords of the brachial plexus, and may involve the cervical sympathetic nerve chain, phrenic, and recurrent laryngeal nerves. It is usually secondary to a benign or malignant tumor. However, a large inflammatory process may cause this syndrome as well. The symptoms are:

a. Pain in shoulder and arm, particularly in the axilla and inner arm.

b. Intrinsic hand muscle atrophy.

c. Horner's syndrome (enophthalmos, ptosis of the upper lid, constriction of the pupil with narrowing of the palpebral fissure, and decreased sweating homolaterally).

10. Congenital agenesis of the lung has been classified by Schneider as follows:

Class I: Total agenesis. Class II: Only the trachea is present. Class III: Trachea and bronchi are present without any pulmonary tissue.

11. Apnea can occur after tracheotomy. This is due to carbon dioxide narcosis causing the medulla to be depressed. Prior to the tracheotomy, the patient was breathing secondary to the lack of oxygen. After the tracheotomy this oxygen drive is removed and hence the patient remains apneic. Treatment for this is to ventilate the patient until the excess carbon dioxide level is reduced. Mediastinal emphysema and pneumothorax are the most common complications of tracheotomy. (For other complications, see Chap. 15).

12. Hypoxemia is defined as less than 75% oxygen saturation or less than 40 mm Hg pO2. A level greater than 5 mg% of met-Hb gives cyanosis.

13. Bronchogenic cyst is a defect at the fourth week of gestation. It constitutes less than 5% of all mediastinal cysts and tumors.

14. The bronchial tree ring is cartilaginous till it reaches 1 mm in diameter. These small bronchioles without cartilaginous rings are held patent by the elastic property of the lung. The bronchial tree is lined by pseudostratified columnar ciliated epithelium as well as nonciliated cuboidal epithelium.

15. The adult trachea measures 10-12 cm and has 16-20 rings. The diameter is approximately 20 mm x 15 mm.

16. The larynx descends on inspiration and ascends on expiration. It also ascends in the process of swallowing and in the production of a high-pitched note.

17. The esophageal lumen widens on inspiration.

18. The total lung surface measures 70 m2. The lung contains 300 million alveoli. The lung secretes 200 mL of fluid per day.

3 19. During inspiration the nose constitutes 79% of the total respiratory resistance, the larynx 6%, and the bronchial tree 15%. During expiration the nose constitutes 74% of resistance, the larynx 3%, and the bronchial tree 23%.

20. Tracheopathia osteoplastica is a rare disease characterized by growths of cartilage and bone within the walls of the trachea and bronchi that produce sessile plaques that project into the lumen. There is no specific treatment other than supportive. It is of unknown etiology. The serum calcium is normal and there are no other calcium deposits.

21. Calcification found in a pulmonary nodule usually implies that it is a benign nodule.

22. Middle lobe syndrome (see Chap. 23).

23. The right upper lobe and its bronchus is the lobe that is most susceptible to congenital anomaly.

24. Cystic fibrosis (mucoviscidosis) is familial, and may be autosomal recessive. The patient presents with multiple polyps, pulmonary infiltration with abscesses, and rectal prolapse. The pancreas is afflicted with a fibrocystic process and produces no enzymes. Trypsin is lacking in the gastric secretion. Ten to fifteen percent of the patients pass trypsin in the stool. There is general malabsorption of liposoluble vitamins. Treatment consists of a high-protein, low-fat diet with water-soluble vitamins and pancreatic extracts. Many patients die of pulmonary abscesses.

25. If a person is ventilated with pure oxygen for 7 minutes, he is cleared of 90% of the nitrogen and can withstand 5-8 minutes without further oxygenation.

The Mediastinum

1. Suprasternal fossa:

a. This is the region in which the sternocleidomastoid muscles converge toward their sternal attachments. Bound inferiorly by the suprasternal notch, they, however, have no superior boundary.

b. The deep cervical fascia splits into an anterior and a posterior portion. These are attached respectively to the anterior and posterior margins of the manubrium.

c. The space between these fascial layers is the small suprasternal space containing:

1) Anterior jugular veins

2) Fatty connective tissues

d. Behind this space lies the pretracheal fascia.

4 e. Laterally on each side are the medial borders of the sternohyoid and sternothyroid muscles.

2. In the adult, the innominate artery crosses in front of the trachea, behind the upper half of the manubrium. In the child, it crosses over the level of the superior border of the sternum.

3. The trachea enters the mediastinum on the right side.

4. The trachea bifurcates at T4-5 or about 6 cm from the suprasternal notch. As a person approaches 65 years of age or more, it is possible that the trachea bifurcates at T6.

5. To the left of the trachea are: aorta, left recurrent laryngeal nerve, lef subclavian artery.

To the right of the trachea are: superior vena cava, azygos vein, right vagus, right lung pleura.

6. The innominate and left carotid arteries lie anterior to the trachea near their origin. As they ascend, the innominate artery lies to the right of the trachea.

7. The pulmonary artery passes anterior to the bronchi and assumes a superior position to the bronchi at the hilus with the exception that the right upper lobe bronchus is superior to the right pulmonary artery.

8. The left main bronchus crosses in front of the esophagus. It presses on the esophagus and together with the aorta forms the bronchoaortic constriction. The first part of the aorta is to the left of the esophagus. As it descends it assumes a left posterolateral position to the esophagus.

9. The course of the esophagus is as shown in Fig. 28-1. The esophagus has four constricting points.

a. Cricopharyngeus muscle

b. Aorta crossing

c. Left main stem bronchus crossing

d. Diaphragm

(a

At the level of c the esophagus passes from superior mediastinum to the posterior mediastinum.

5 10. The following structures are found within the concavity of the aorta:

a. Left main stem bronchus

b. Left recurrent laryngeal nerve

c. Tracheobronchial nodes

d. Superficial part of the cardiac plexus.

11. The right main stem bronchus is wider, shorter, and follows a more vertical course than the left one.

12. The inferior thyroid vein is immediately in front of the trachea in its infraisthmic portion.

13. Ten percent of the population has a thyroidea ima artery. It arises from either the innominate artery or the aorta. It passes upward along the anterior aspect of the trachea.

The Course of the Vagus

Left:

1. It passes inferiorly between the left subclavian and the left carotid.

2. It follows the subclavian to its origin.

3. It passes to the left of the arch of the aorta.

4. It gives off the recurrent laryngeal nerve which passes superiorly along the left border of the tracheoesophageal groove (between the esophagus and trachea).

5. The main vagus continues to descend behind the left main stem bronchus.

Right:

1. It descends anterior to the subclavian where it gives off the recurrent laryngeal nerve which loops around the subclavian artery and ascends posteromedial to the right common carotid artery to reach the tracheoesophageal groove (between the esophagus and the trachea)

2. The main trunk descends posteriorly along the right side of the trachea, between the trachea and right pleura.

3. It descends posterior to the right bronchus.

6 Fascia of the Mediastinum

The space between the various organs is occupied by loose areolar tissue. The fascial layers of the mediastinum are a direct continuation of the cervical fascia. A portion of the cervical fascia, the perivisceral fascia, encloses the larynx, pharynx, trachea, esophagus, thyroid, thymus, and carotid sheath contents. This space enclosed by this perivascular fascia extends to the bifurcation of the trachea. Anteriorly it is bound by pretracheal fascia. The pretracheal fascia is an important landmark in mediastinoscopy in that dissection should be done only beneath this layer.

Boundaries of the Mediastinum (Fig. 28-2)

1. Lateral: parietal pleura

2. Anterior: sternum

3. Posterior: vertebra

4. Inferior: diaphragm

5. Superior: superior aperture of the thorax.

Superior Mediastinum

1. Boundaries:

Superior: superior aperture of the thorax

Anterior: manubrium with sternothyroid and sternohyoid muscles

Posterior: upper thoracic vertebra

Inferior: plane from manubrium to IV vertebra.

2. Structures of the superior mediastinum: thymus, innominate veins, aorta, vagus, resurrent laryngeal nerve, phrenic nerve, azygos vein, esophagus, thoracic duct.

Anterior Mediastinum

It lies between the body of the sternum and the pericardium and contains:

1. Loose areolar tissue

2. Lymphatics

3. Lymph nodes

4. Thymus gland.

7 Middle Mediastinum

It contains the heart, ascending aorta, superior vena cava, azygos vein, bifurcation of the main bronchus, pulmonary artery trunk, right and left pulmonary veins, phrenic nerves, and the tracheal-bronchial lymph nodes.

Posterior Mediastinum

Anteriorly lies the bifurcation of the trachea, the pulmonary vein, the pericardium, and the posterior part of the upper surface of the diaphragm. Posteriorly lies the vertebral column from T-4 to T-12. Laterally lies the mediastinal pleura.

The posterior mediastinum contains the thoracic aorta, azygos vein, hemiazygos vein, cranial nerve X, splanchnic nerve, esophagus, thoracic duct, posterior mediastinal lymph nodes, and the intercostal arteries.

Lymph Nodes of the Thorax (Fig. 28-3)

1. Parietal nodes are inconsequential clinically. They are grouped into intercostal, sternal, and phrenic nodes.

2. Visceral nodes are of greater clinical importance. They are grouped as follows:

a. Peritracheobronchial

1) Paratracheal

2) Pretracheal

3) Superior tracheobronchial

4) Inferior tracheobronchial

b. Bronchopulmonary

c. Anterior mediastinal or prevascular

d. Pulmonary

e. Posterior mediastinal.

8 Lymphatic Drainage of the Lung

1. Right

Superior area (anteromedial area of the right upper lobe): right paratracheal nodes.

Middle area (posterolateral area of right upper lobe, right middle lobe, and superior right lower lobe): right paratracheal nodes and inferior tracheal-bronchial nodes.

Inferior area (lower half of right lower lobe): inferior tracheal-bronchial nodes and posterior mediastinal nodes.

2. Left

Superior area (upper left upper lobe): left paratracheal, anterior mediastinal, and subaortic nodes.

Middle area (lower left upper lobe and upper left lower lobe): left paratracheal, inferior tracheobronchial, and anterior mediastinal nodes.

Inferior area (inferior part of the left lower lobe): inferior tracheobronchial nodes.

The left inferior tracheobronchial nodes drain into the right paratracheal nodes.

3. Right upper lung --> right neck.

Right lower lung --> right neck.

Left lower lung --> right neck.

Left upper lung --> left neck.

Lingular lobe --> both sides of the neck.

Purposes of Mediastinoscopy

Barium swallow and tracheogram are usually obtained before mediastinoscopy if indicated.

1. Histologic diagnosis

2. To determine which nodes are involved

3. To make the diagnosis of sarcoidosis.

9 Mediastinal Tumors

1. One-third of all mediastinal tumors are malignant. Among the malignant ones, lymphoma is most commonly encountered.

2. Superior mediastinum: Thyroid, neurinoma, thymoma, parathyroid.

Anterior mediastinum: Dermoid, teratoma, thyroid, thymoma.

Low anterior mediastinum: Pericardial cyst.

Middle mediastinum: Pericardial cyst, bronchial cyst, lymphoma, carcinoma.

Posterior mediastinum: Neurinoma and enterogenous cyst.

Superior Vena Cava Syndrome

1. Etiology: Malignant metastasis, mediastinal tumors, mediastinal fibrosis, vena cava thrombosis.

2. Signs and symptoms include: Edema and cyanosis of the face, neck, and upper extremities. Venous hypertension with dilated veins. Normal venous pressure of lower extremities. Visible venous circulation of the anterior chest wall.

Endoscopy

Size of Tracheotomy Tubes and Bronchoscopes

Age Tracheotomy Bronchoscope

Premature No. 000 x 26 to No. 00 x 33 mm 3 mm 6 months No.0x33mmtoNo.0x40mm 3.5mm 18 months No.1x46mm 4mm 5 years No.2x50mm 5mm 10 years No.3x50mmtoNo.4x68mm 6mm Adult 7 mm

Size of Esophagoscope

Child 5 x 35 or6x35cm Adult 9 x 50 cm.

10 During esophagoscopy, the average distance from the incisor teeth to the:

Adult 3 years 1 years Birth

Cricopharyngeus muscle 16 cm 10 9 7 Aorta 23 cm 15 14 12 Left bronchus 27 cm 16 15 13 Hiatus 38 cm 23 21 19 Cardiac 40 cm 25 23 21 Greater curvature of the stomach 53 cm 30 27 23.

Left Lung

Lobes Segments

Upper division of upper lobe a. Apical-posterior b. Anterior

Lower division of upper lobe a. Superior b. Inferior

Lower lobe a. Superior b. Anteromedial basal c. Lateral basal d. Posterior basal

Right Lung

Lobes Segments

Upper lobe a. Apical b. Posterior c. Anterior

Middle lobe a. Lateral b. Medial

Lower lobe a. Superior b. Medial basal c. Anterior basal d. Lateral basal e. Posterior basal.

11 Relative contraindications for esophagoscopy:

1. Aneurysm of the aorta.

2. Spinal deformities, osteophytes.

3. Esophageal burns and being treated with steroids.

Relative contraindications for bronchogram:

1. Acute infection.

2. Acute asthmatic attacks.

3. Acute cardiac failure.

Causes for hemoptysis: (in order of decreasing frequency)

1. Bronchiectasis.

2. Adenoma.

3. Tracheobronchitis.

4. Tuberculosis.

5. Mitral stenosis.

Foreign bodies:

Right upper lobe bronchus: most common Left upper lobe brocnhus: second most common Trachea: least likely

Most common site for esophageal foreign bodies is the cervical esophagus.

Most common foreign bodies in childrean are peanuts, safety pins, coins.

Most common foreign bodies in adults are meat and bone.

Vascular Anomalies (See Chap. 11, Fig. 11-2a, b, c)

1. Double aortic arch: This is a true vascular ring. It is due to the persistence of the right fourth branchial arch vessel. The symptoms include stridor, intermittent dysphagia, and aspiration pneumonitis. The right posterior arch is usually the largest of the two arches.

12 2. Right aortic arch with ligamentum arteriosum: This is due to the persistence of the right fourth branchial arch vessel becoming the aorta instead of the left fourth arch vessel. This crosses the trachea causing an anterior compression.

3. Anomalous right subclavian artery: This is due to the right subclavian artery arising from the dorsal aorta giving a posterior compression of the esophagus. There is no constriction over the trachea.

4. Anomalous innominate and/or left common carotid: The innominate arises too far left from the aorta. It crosses the trachea anteriorly causing an anterior compression. The left common carotid arises from the aorta on the right or from the innominate artery. It also causes an anterior compression of the trachea. In another variant of this anomaly, the innominate and the right common carotid arise from the same trunk and in dividing, encircle the trachea and esophagus causing airway obstruction as well as dysphagia.

5. Patent ductus arteriosus.

6. Coarctation of the aorta.

7. An enlarged heart especially with mitral insufficiency can compress on the left bronchus.

8. Dysphagia lusoria is a term used to include dysphagia caused by any aberrant great vessel. The common cause if an abnormal subclavian artery arising from the descending aorta.

9. Anomalous innominate arteries have been estimated to be the most common vascular anomaly. They cause an anterior compression on the trachea. During bronchoscopy if the pulsation is obliterated with the bronchoscope, the radial pulse on the right arm is reduced while the temporal pulse is also reduced. In the case of a subclavian anomaly the bronchoscope compressing the abnormal subclavian produces a decrease of the radial pulse but the temporal pulse will remain normal. A bronchoscope compressing a double aortic arch pulsation will produce no pulse changes in either the radial or temporal pulse.

Basic Pulmonary Physiology

To most physicians, pulmonary physiology is a complex discipline whose subject matter lies beyond the grasp of all but those specifically involved in pulmonary medicine. However, all practitioners should be acquainted with the fundamentals of lung function. In particular, otolaryngologists should have more than a cursory comprehension of pulmonary physiology since many of their patients will have diseases affecting both the upper airway and the lungs themselves.

This section will attempt to review the basic concepts of pulmonary physiology in a simple and concise manner.

13 Definitions

To follow the text below, the reader will need to be familiar with the following definitions:

Lung Volumes

Lung volumes can be divided into "primary volumes" and "capacities".

1. Volumes

a. Tidal volume (TV): the tidal volume is the volume of gas which is either inspired or expired during each respiratory cycle.

b. Residual volume (RV): the residual volume is the amount of gas which remains in the lungs at the end of a maximal expiratory effort.

2. Capacities

a. Total lung capacity (TLC): the total lung capacity is the amount of gas contained in the lungs at the end of a maximal inspiratory effort.

b. Vital capacity (VC): the vital capacity is the maximum volume of gas which is expelled when a patient makes a forceful effort after inspiring to his total lung capacity.

c. Functional residual capacity (FRC): the functional residual capacity is the volume of gas which remains in the lungs at resting expiratory level.

Dynamic Lung Volumes

1. Forced expiratory volume in 1 second (FEV1): FEV1 is the volume of gas which is expelled from the lungs during the first second after the initiation of a forceful effort following a maximal inspiration.

2. FEV1/FVC ratio: The FEV1/FVC ratio is the ratio of the volume of gas expelled from the lungs 1 second after forceful effort following a maximal inspiration divided by the maximum volume of gas which is expelled from the lungs by forceful effort following a maximal inspiration.

With the above definitions in mind, we can now turn our attention to pulmonary function testing and what it can reveal to us about the status of a patient's lungs.

Spirometry

The spirometer is the most useful piece of equipment in a pulmonary function testing laboratory because, using a spirometer and a nitrogen or helium analyzer, one can obtain values for the lung volumes, capacities, and dynamic lung volumes. By analyzing the data obtained, a physician can determine whether a patient has normal or abnormal lung function.

14 Abnormal lung function has generally been divided into two main categories: (1) airflow limitation, commonly referred to as obstructive lung diseases, and (2) restrictive lung disease.

Diseases Producing Obstruction to Air Flow

Any disease process which impedes the flow of air through an airway of over 2 mm in size will produce spirometric evidence for limitation to airflow. This limitation to airflow will often be seen in a reduction in the vital capacity and in the FEV1. In addition, one will find a diminution of the FEV1/FVC ration below the predicted normal. There often is an elevation in the functional residual capacity and the residual volume, and in severe cases, air trapping with an increase in total lung capacity may be seen. The finding of airflow limitation on pulmonary function testing does not indicate the cause of the patient's disease. Asthma, chronic bronchitis, and pulmonary emphysema will all produce evidence for airflow limitation. When a tracing reveals evidence for airflow limitation, the patient should be given a bronchodilator. Patients with asthma most often demonstrate a reversible component to their airway narrowing. When these patients are given a bronchodilator in the laboratory and the pulmonary function is repeated, an improvement is often seen in their studies. Most laboratories regard an improvement in FVC or FEV1 of 20% or more as an indication of reversibility. Lack or response to the bronchodilator does not mean that a patient does not have an element of reversibility, but on the other hand, an improvement in function after bronchodilator does indicate that there is a reversible component to the airflow limitation.

Patients with diseases considered to be nonreversible, such as pulmonary emphysema, most often will not demonstrate any reversibility in airflow limitation after the administration of a bronchodilator. Patients scheduled for surgery, who demonstrate evidence for airflow limitation on initial testing, should universally be given a bronchodilator. Preoperative bronchodilator therapy may greatly improve their pulmonary function, and hence reduce their operative risk if used for a significant time in the preoperative and postoperative period.

Patients with restrictive lung disease demonstrate a different pattern of pulmonary function abnormality. In patients with restrictive disease, there is a redeuction in the volume of air that can be inspired. There are many disease entities that will lead to restriction. Surgical removal of lung tissue, restricted expansion of the lungs (such as may be seen in scoliosis or fibrothorax), or neurologic disorders (such as amyotrophic lateral sclerosis) which produce muscular weakness, demonstrate a restrictive pattern. In addition, diseases which replace lung tissue with granulomas also produce a restrictive pattern. This pattern is characterized in general by a reduction in vital capacity, forced vital capacity, and FEV1, but with preservation of the FEV1/FVC ration. In reviewing pulmonary function data, it is important to evaluate the FEV1/FVC ratio since both obstructive and restrictive disease will produce reductions in forced vital capacity and FEV1. However, in airflow limitation, the FEV1/FVC ratio will be reduced, whereas in restriction, the FEV1/FVC ratio will be preserved.

Moreover, in obstructive disease, the total lung capacity is often normal or high, whereas in restriction, the total lung capacity will be found to be reduced. Patients with restrictive disease do not demonstrate improvement after the administration of a bronchodilator since the defect in restrictive disease does not lie in narrowing of the airways.

15 In addition to spirometric data, other techniques have recently been used to study basic pulmonary function.

Flow Volume Loops

The maximal expiratory flow volume curve has been in use for the past several years. In contrast to the spirometer, in which volume is plotted against time, in the flow volume loop one measures flow as a function of lung volume. Conditions that produce airflow limitation will demonstrate reduction in flow throughout the patient's forced vital capacity maneuver. This can be seen in the accompanying Fig. 28-6, and usually presents as a concave curve in contrast to the normal convex curve seen in patients without disease. Note that the flow volume loop also provides data about inspiration. This will be discussed in subsequent sections. A bronchodilator also can be administered to a patient following a flow volume loop. An improvement in the loop also is indicative of reversible airflow limitation.

Patients with restrictive disease demonstrate a reduction in vital capacity but, as can be seen in the accompanying diagram (Fig. 28-7), the slope of the expiratory loop is normal, indicating that there is no reduction in flow rate. Many devices employing flow volume loop techniques are available for "pulmonary function screening". It should be noted that a number of these devices do not contain the additional equipment needed to determine lung volumes such as FRC and RV. Consequently these cannot provide information regarding total lung capacity.

Additional Values of the Flow-Volume Curve

In addition to providing evidence concerning basic lung function, the flow-volume loop can be used to detect upper airway obstruction - a most useful test for the otolaryngologist.

The ability of the flow-volume loops to detect upper airway obstruction is based on the following physiologic principle: When a patient inspires, atmospheric pressure is greater than intratracheal pressure. For this reason, when a patient inspires, the atmospheric pressure tends to narrow the trachea. If there is an "extrathoracic" (or upper airway) obstruction, any narrowing of the extrathoracic lumen will be magnified on inspiration. Hence, the inspiratory loop of the flow volume curve will be flattened. On the expiratory portion of the flow volume loop, the intratracheal pressure is greater than atmospheric pressure. Thus, any narrowing produced by a variable resistance will be eliminated and the expiratory loop of the flow volume loop will be normal. Extra thoracic obstruction is therefore characterized by a flattened inspiratory loop with a relatively normal expiratory loop (Fig. 28-8).

In the intrathoracic cavity, the airways enlarge on inspiration. This is because inspiration produces higher lung volumes, and because the lung parenchyma exerts a tethering action on airways, lung inflation produces an increase in airway diameter. On expiration, the intrathoracic pressure increases, lung volumes decrease, and the airways narrow. Hence, any lesion which produces intrathoracic obstruction will be most manifest on expiration. Intrathoracic obstructions will be characterized by a normal inspiratory loop but an abnormal expiratory loop (Fig. 28-9).

16 Lung Compliance

One of the most important concepts in pulmonary physiology relates to the compliance of the lungs. Compliance is regarded as a measure of distensibility. A structure that is easily distended by small changes in pressure is felt to be highly compliant. For example, a lung whose elastic tissue has been destroyed, such as an emphysematous lung, will be easily distended by small changes in pressure. This will produce a compliance curve shown in Fig. 28-10. Highly distensible lungs are inelastic, as opposed to a "stiff lung", which is poorly distensible and highly elastic. It will take a large pressure change to evoke a significant change in the lung volume. As an example, patients with pulmonary fibrosis have stiff lungs. These lungs require high pressure gradients to produce significant changes in lung volume. Thus pressure volume relationship can be seen in Fig. 28-10.

Since the adequacy of ventilation is determined in part by alveolar ventilation, it is important for the physician to consider the compliance characteristics of the lung in any patient who is being mechanically ventilated. Patients with highly compliant lungs will require small pressure changes to induce large volume changes, whereas in patients with stiff lungs, high pressures may be needed to generate adequate volumes for ventilatory demands.

Diffusing Capacity

When pulmonary physicians talk about diffusing capacity of the lung, they are referring to the quantity of a specific gas that diffuses across the alveolar capillary per unit time. A full discussion of diffusing capacity is beyind the scope of this text. In most pulmonary laboratories, the gas used to measure the diffusing capacity of the lung is carbon monoxide. Carbon monoxide is rapidly bound to hemoglobin and in clinical practice, the diffusion capacity is felt to represent the volume of capillary blood into which the carbon monoxide can dissolve. Hence, diseases such as emphysema, characterized by a reduction in capillary blood volume, will have associated low diffusion capacities.

Blood Gas Interpretation

It must be emphasized that total ventilation (tidal volume x respiratory frequency) is not the same as alveolar ventilation (volume of gas in each breath which participates in gas exchange x respiratory frequency). For the purposes of clinical medicine, alveolar and arterial carbon dioxide tensions are equal. Since alveolar ventilation is the factor which determines

the level of arterial pCO2, the adequacy of ventilation is assessed by measuring the arterial pCO2.

Hypoxemia

In clinical practice the most common causes of hypoxemia include two main factors: (1) simple hypoventilation and (2) ventilation-perfusion inequality. Other causes for hypoventilation include anatomic shunts and abnormalities of diffusion. The latter two are rarely found in a clinical practice and will not be discussed.

A useful technique for evaluating the presence of intrinsic lung disease is determination of the alveolar-arterial or A-a gradient. One simple way to do this is to assume

17 that the alveolar pO2 is equal to 148 - the arterial pCO2 x 1.2. If, in general, an arterial oxygen tension is below normal but the A-a gradient is measured as less than 10 mm Hg, it is most likely that alveolar hypoventilation is the sole abnormality producing hypoxemia. In hypoventilation that is caused by primary lung disease per se, the A-a gradient is elevated. Abnormally low arterial oxygen tensions produced by uncomplicated alveolar hypoventilation can be corrected merely by improving the level of the alveolar ventilation. Diseases that produce widened A-a gradients often will produce hypoxemia that cannot be completely corrected by simply increasing the level of alveolar ventilation. The most common cause of hypoxemia in patients is a maldistribution of alveolar ventilation and pulmonary blood flow. Diseases such as asthma and bronchitis impair ventilation and hence disturb ventilation/blood flow relationships. Our treatment of hypoxemia caused by ventilation-perfusion abnormalities may be illustrated in Fig. 28-11. If the alveolus 1 has a reduction in ventilation due to airway narrowing, then the arterial oxygen tension in blood vessel I flowing past alveolus 1 will be reduced. Alveolus 2, which receives normal ventilation, will fully saturate the hemoglobin that flows past it in blood vessel II. As a result, the arterial oxygen tension in blood vessel III will be reduced since it is a composite of blood from blood vessel I and II. However, ventilation perfusion relationships cannot be compensated by simpe hyperventilation; since simple hyperventilation cannot improve the saturation of blood in vessel II, nor significantly raise the arterial oxygen tension in alveolus 1. If, however, the tension of inspired oxygen is raised, then the oxygen tension in alveolus 1 will rise and thus increase the saturation of hemoglobin in vessel I. As a result, the arterial oxygen tension of vessel III will be increased. It is for this reason that diseases characterized by ventilation-perfusion mismatching do show improvement with higher inspired oxygen tensions. It should be apparent that if there is a true anatomic shunt present around alveolus 1 (Fig. 28-12), raising the inspired oxygen tension will not result in any improvement in arterial oxygen tension since the hemoglobin molecules in vessel II are already fully saturated and there is no blood gas exchange in alveolus 1. True shunts, therefore, do not respond to increases in inspired oxygen tension.

It is important to emphasize at this juncture that patients with longstanding ventilation- perfusion mismatching with advanced pulmonary disease often have had chronic hypoxemia

and CO2 retention. These patients no longer have their respiratory drive determined by hydrogen ion concentration and are deriving their respiratory drive in a large part from their arterial oxygen tensions. The injudicious correction of arterial oxygen tension may, therefore, lead to a cessation of respiratory drive. It is for this reason that venti-masks using high-flow system that controls the inspired oxygen tension closely, or low-flow oxygen systems using 1 or 2 L of flow, should be employed in the treatment of patients with significant ventilation- perfusion abnormalities.

18 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 29: Related Ophthalmology

Anatomy

1. The orbit forms a quadrilateral pyramid: floor, roof, medial wall, and lateral wall.

Roof: orbital process of the frontal bone; lesser wing of the sphenoid.

Floor: orbital plate of maxilla; orbital surface of zygoma; orbital process of palatine bone.

Medially: frontal process of maxilla; lacrimal bone; sphenoid bone; lamina papyracea of the ethmoid bone.

Laterally: lesser and greater wings of the sphenoid; zygoma.

2. The trochlea, a pulley through which runs the tendon of the superior oblique muscle, is located between the roof and the medial wall. A displaced trochlea will give diplopia on downward gaze.

3. The inferior orbital fissue is in the floor of the orbit. It is bound by the greater wing of the sphenoid, orbital surface of the maxilla, and orbital process of the palatine bone. It transmits the infraorbital nerve, infraorbital vessels, zygomatic nerve, twigs from the sphenopalatine ganglion to the lacrimal gland, and ophthalmic vein branch.

4. The anterior and posterior ethmoid foramina are situated at the junction between the frontal and ethmoid bone (but they are on the frontal bone per se).

5. The superior orbital fissure lies between the roof and the lateral wall of the nose. It is a gap between the lesser and the greater wings of the sphenoid. It transmits cranial nerves III, IV, VI, V1, the superior orbital vein, ophthalmic vein, orbital branch of middle meningeal artery, and recurrent branch of lacrimal artery.

6. The optic canal runs from the middle cranial fossa into the apex of the orbit. It is formed by the two roofs of the lesser of the lesser wing of the sphenoid. It transmits the optic nerve and the ophthalmic artery.

7. The upper lid contains:

a. Orbicularic oculi.

b. Levator palpebrae superioris.

c. Sweat glands.

d. Meibomian glands.

1 e. Wolfring's glands.

f. Tarsal plate.

8. The lower lid contains:

a. Tarsal plate.

b. Orbicularis oculi.

c. Sweat glands.

d. Meibomian glands.

e. Wolfring's glands.

9. The lateral ends of the tarsi unite to form the lateral palpebral ligament which fixes onto the orbital surface of the zygomatic bone. A displaced lateral canthal ligament may give an inferiorly displaced canthus or slight ptosis.

10. The medial ends join to form the medial palpebral ligament which is attached to the frontal process of the maxilla immediately in front of the lacrimal fossa. Displacement of the medial palpebral ligament gives rise to a rounding of the medial canthus or pseudohypertelorism. The medial palpebral ligament sends a few fibers to be attached to the posterior lacrimal crest. This is believed to keep Horner's muscle in place which in turn maintains the lacrimal puncta against the globe. Hence, displacement of Horner's muscle may lead to epiphora.

11. The septum orbitale is the orbital periosteum which extends into the lid to attach to the tarsal plates. It separates the orbital contents from the lacrimal apparatus. Medially, it is fused with the palpebral ligament leading toward the posterior lacrimal crest.

12. The suspensory ligament of Lockwood is a continuous band of fibrous tissue slung beneath the eyeball from side to side. The ends of the suspensory ligament blend with the check ligaments and with the medial and lateral horns of the aponeurosis of the levator palpebrae superioris.

Control of Eye Movement

1. The six extraocular muscles and their functions are:

Lateral rectus to abduct Medial rectus to adduct Superior rectus to elevate (and intort) Inferior rectus to depress (and extort) Superior oblique to intort (and depress) Inferior oblique to extort (and elevate).

2 2. LR6(SO4), the rest by III.

The lateral rectus is innervated by the VI nerve. The superior oblique is innervated by the IV nerve. The rest of the extraocular muscles are innervated by the III nerve.

3. The inferior rectus muscle is the most commonly trapped muscle in a blow-out fracture, the second being the inferior oblique. When these muscles are trapped, the patient may experience difficulty looking upward. This condition is not due to paralysis but rather to the trapping of the two muscles mentioned above. To differentiate paralysis of the elevators from trapping of the inferior rectus and the inferior oblique muscles, the "forced duction test" is performed under local or general anaesthesia. The forced duction test consists of grasping the globe adjacent to the limbus with small forceps and rotating it up, down, in, and out. If the globe moves freely, there is no entrapment of the these muscles.

4. There are six cardinal directions of gaze, each controlled by a set of two muscles:

Eyes to right: right lateral rectus and left medial rectus. Eyes to left: right medial rectus and left lateral rectus. Eyes up and right: right superior rectus and left inferior oblique. Eyes down and right: right inferior rectus and left superior oblique. Eyes up and left: right inferior oblique and left superior rectus. Eyes down and left: right superior oblique and inferior rectus.

When diplopia occurs it may exist in more than one direction. The muscles suspected of being involved are those controlling the direction of gaze in which the images of the diplopia are farthest apart. It is usually obvious as to which eye is involved. However, when such is not the case, each eye should be covered in turn and tested. The eye that sees the peripherial image is the one injured.

Lacrimal System

1. The lacrimal gland (a serous gland predominantly) is located in a fossa within the zygomatic process of the frontal bone. The lacrimal sac lies in a fossa bound by the lacrimal bone, the frontal process of the maxilla, and by the nasal process of the frontal bone.

2. The lacrimal gland secretes tears through 17-20 openings. Although the gland is developed, secretion of tears does not take place until 2 weeks after birth.

3. When cannulating the inferior and superior canaliculi, it is important to remember that each canaliculus has a vertical portion (about 2 mm) and a longer horizontal portion (about 8 mm). The lacrimal sac is about 12 mm long and the duct about 17 mm in length. The nasolacrimal duct empties into the anterior portion of the inferior meatus. This area is to be avoided when creating a nasoantral window. The most common site of obstruction in the lacrimal system is the upper portion of the nasolacrimal duct giving rise to dacrocystitis, the symptoms of which are epiphora and pain.

3 4. A lacerated canaliculus should be sutured together if possible. If not, a silk string or polyethylene tube should be passed from one canaliculus to the other.

5. A lacerated nasolacrimal duct can be sutured primarily over a polyethylene stent passing from the canaliculus to the nose. If the lacerated ends cannot be identified, then a polyethylene tube passing from the canaliculus into the nose can be left in place for 2-3 weeks.

Malignant Exophthalmos

1. Malignant exophthalmos is caused by an endocrine disorder. One of the causes is an oversecretion of "exophthalmos factor" by the anterior pituitary. The factor is possibly linked to TSH. The more severe form of exophthalmos is caused by excessive orbital edema giving rise to an increase in bulk of the extraocular muscles and adipose tissues. These adipose tissues are found at such time to contain a greater amount of mucopolysaccharides than normally.

2. The exophthalmos is not only undesirable but can lead to:

a. Corenal abrasions (due to an inability to properly close the eye).

b. Chemosis secondary to venous stasis.

c. Fixation of the extraocular muscles causing ophthalmoplegia. The earliest limitation noted is in the upward gaze.

d. Retinal venous congestion leading to blindness.

3. Since the consequences of malignant exophthalmos are grave, many surgical corrections have been devised.

a. Kronlein's procedure removes the lateral orbital wall to allow the orbital contents to expand into the zygomatic area.

b. Naffziger's procedure removes the roof of the orbital cavity to allow expansion of the orbital contents into the anterior cranial fossa. It does not expose any of the paranasal sinuses and it preserves the superior orbital rim. Postoperatively, the cerebral pulsations may be noticed in the orbit.

c. Sewell's procedure consists of an ethmoidectomy and removal of the floor of the frontal sinus for expansion.

d. Hirsch's procedure removes the orbital floor to allow decompression into the maxillary sinus. A ridge of bone around the intraorbital nerve is preserved to support the nerve.

4 e. Ogura has described a method in which the floor and the medial wall of the orbit are removed to allow expansion into the ethmoid and maxillary sinus. As complete an ethmoidectomy as possible is performed.

5 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 30:Related Neurology

Multiple Sclerosis

Multiple sclerosis is a chronic disease characterized physiologically by the presence of numerous areas of demyelinization in the central nervous system, and clinically, by a variety of neurologic signs and symptoms which have a tendency toward remission and exacerbation. It is primarily a disease of the young adult. The most common symptoms in multiple sclerosis are weakness and paresthesias. Vertigo is the presenting symptom of this disease in 7-10% of the patients and it eventually appears during the course of the disease in up to one-third of the cases. Deafness, on the other hand, is rare, while involvement of the extraocular muscles gives diplopia. Nystagmus is present in about 70% of all cases of multiple sclerosis. The nystagmus, most commonly of the horizontal type, is observed only on lateral gaze. Vertical nystagmus is present in about 33% of the cases. While oscillopsia (rapid oscillations of the eyes in the horizontal plane) is occasionally seen, internuclear ophthalmoplegia is a common ocular manifestation of this disease. In internuclear ophthalmoplegia, the internal recuts on one side is paralyzed while the external rectus on the opposite side is weak, thus producing nystagmoid jerks of the outwardly deviating eye (monocular nystagmus or ataxic nystagmus). Internuclear ophthalmoplegia rarely occurs in other disease, hence its presence is pathognomonic of multiple sclerosis.

Multiple sclerosis has an inherited predisposition although not inherited according to mendelian laws.

Charcot's triad in multiple sclerosis includes nystagmus, scanning speech, and intention tremor.

Myasthenia Gravis

Myasthenia gravis is a disease characterized by weakness and abnormal fatigability of the striated muscles. Its pathophysiology is believed to be impaired transmission across the myoneural junction. The usual age of involvement varies from 5-40 years of age. Children born of a myasthenia gravis mother have neonatal myasthenia gravis symptoms. Their chief symptom is an inability to suck and swallow. The cricopharyngeus muscle, which is not involved in poliomyelitis, is involved in myasthenia gravis. Like multiple sclerosis, remissions and exacerbations are characteristic of this disease. Ocular muscle involvement is present in 40% of the cases. Facial, laryngeal, and pharyngeal muscles often are involved. A distinctive trait of this disease is that the weakness is greatest after exercise and at the end of the day. Nystagmus and vertigo seldom occur.

The diagnosis is made from the patient's medical history together with the neostigmine (Prostigmin or Tensilon) test.

Tensilon (Edrophonium Chloride, PDR, 1981).

1 Tension is a short and rapid-acting cholinergic drug. Chemically, edrophonium chloride is ethyl (m-hydroxylphenyl)-dimethylammonium chloride.

10-mL vials: Each milliliter contains, in a sterile solution, 10 mg edrophonium chloride compounded with 0.45% phenol and 0.2% sodium sulfite as preservatives, buffered with sodium citrate and citric acid, and pH adjusted to approximately 5.4.

1-mL ampules: Each milliliter contains, in a sterile solution, 10 mg edrophonium chloride compounded with 0.2% sodium sulfite, buffered with sodium citrate and citric acid, and pH adjusted to approximately 5.4.

Actions: Tensilon is an anticholinesterase drug. Its pharmacologic action is due primarily to the inhibition or inactivation of acetylcholinesterase at sites of cholinergic transmission. Its effect is manifest within 30-60 seconds after injection and lasts an average of 10 minutes.

Indications: Tensilon is recommended for the differential diagnosis of myasthenia gravis and as an adjunct in the evaluation of treatment requirements in this disease. It may also be used for evaluating emergency treatment in myasthenic crises. Because of its brief duration of action, it is not recommended for maintenance therapy in myasthenia gravis.

Tensilon is also useful whenever a curare antagonist is needed to reverse the neuromuscular block produced by curare, tubocurarine, gallamine triethiodide, or dimethyl- tubocurarine. It is not effective against decamethonium bromide and succinyl-choline chloride. It may be used adjunctively in the treatment of respiratory depression caused by curare overdosage.

Contraindications: Known hypersensitivity to anticholinesterase agents; intestinal and urinary obstructions of mechanical type.

Warnings: Whenever anticholinesterase drugs are used for testing, a syringe containing 1 mg of atropine sulfate should be immediately available to be given in aliquots intravenously to counteract severe cholinergic reactions which may occur in the hypersensitive individual, where he is normal or myasthenic. Tensilon should be used with caution in patients with bronchial asthma or cardiac dysrhythmias.

Dosage

Intravenous Dosage (Adults): A tuberculin syringe containing 1 mL (10 mg) of Tensilon is prepared with an intravenous needle, and 0.2 mL (2 mg) is injected intravenously within 15-30 seconds. The needle is left in situ. Only if no reaction occurs after 45 seconds is the remaining 0.8 mL (8 mg) injected. If a cholinergic reaction (muscarinic side effects, skeletal muscle fasciculations, and increased muscle weakness) occurs after injection of 0.2 mL (2 mg)), the test is discontinued and atropine sulfate 0.4 mg to 0.5 mg is administered intravenously. After one-half hour the test may be repeated.

Intramuscular dosage (Adults): In adults with inaccessible veins, dosage for intramuscular injections is 1 mL (10 mg) of Tensilon. Subjects who demonstrate

2 hyperreactivity to this injection (cholinergic reaction) should be retested after one-half hour with 0.2 mL (2 mg) of Tensilon intramuscularly to rule out false-negative reactions.

Dosage (Children): The intravenous testing dose of Tensilon in children weighing up to 75 lb is 0.1 mL (1 mg); above this weight, the dose is 0.2 mL (2 mg). If there is no response after 45 seconds, it may be titrated up to 0.5 mL (5 mg) in children under 75 lb, given in increments of 0.1 mL (1 mg) every 30-45 seconds and up to 1 mL (10 mg) in heavier children. In infants, the recommended dose is 0.05 mL (0.5 mg). Because of technical difficulty with intravenous injection in children, the intramuscular route may be used. In children weighing up to 75 lb, 0.2 mL (2 mg) is injected intramuscularly. In children weighing more than 75 lb, 0.5 mL (5 mg) is injected intramuscularly. All signs which would appear with the intravenous test appear with the intramuscular test except that there is a delay of 2-10 minutes before a reaction is noted.

Tensilon Test for Evaluation of Treatment Requirements in Myasthenia Gravis: The recommended dose is 0.1 mL to 0.2 mL (1 mg to 2 mg) of Tensilon, administered intravenously 1 hour after oral intake of the drug being used in treatment. Response will be myasthenic in the undertreated patient, adequate in the controlled patient, and cholinergic in the overtreated patient.

Migraine Headache

Migraine headache can take various forms. It is usually severe, periodic, unilateral, and lasts for houts. The patient is free of headache between attacks. There is familial tendency with onset at adolescence and prevalence in females.

The headache can be localized at the temporal, retro-orbital, or frontal region. It is preceded by an aura, usually visual. Associated with the headache, the patient may have photophobia, pallor, dizziness, tinnitus, paresthesias, nausea, vomiting, and diarrhea.

It is believed that the etiology is "vascular" and the symptoms precipitated or aggravated by stress. Ergotamine tartarate (Cafergot) has been used to treat the attacks, while methysergide maleate (Sansert) is used for the prevention or reduction of their intensity and frequency. However, Sansert has been reported to cause severe complications, i.e. retrolental fibrosis, pleuropulmonary fibrosis, and cardiac complications.

Cluster Headaches (Histamine Cephalgia, Horton's Syndrome, Nasociliary Neuralgia)

Cluster headaches is typified by bouts of attacks for a few days between months or years of remission. It often occurs in young adults. The headache is severe, unilateral, lasts less than an hour, and often awakes the patient from a sound sleep. It may be associated with scleral injection, lacrimation, ipsilateral rhinorrhea, and nasal congestion. The treatment is similar to that for migraine headache.

3 Temporal Arteritis

Temporal arteritis mainly strikes those in their 50s and 60s. Its pathology is similar to that of periarteritis nodosa except for a more severe inflammatory reaction around the vessels and for the presence of many multinucleated giant cells in the media (giant cell arteritis). It usually is restricted to the temporal arteries.

The patient suffers severe pain along the arteries, feels lethargic, and has a low-grade fever. Temporal arteritis is usually a self-limiting disease unless the central artery of the retina is involved in which case residual blindness would be present. The treatment for this disease consists of steroid administration.

Sarcoidosis

Sarcoidosis is a multifaceted disease of unknown etiology. Pathologically, epitheloid cell tubercles are found without evidence of necrosis or caseation. Giant cells containing calcified bodies are identified in these tubercles. The usual age of onset is between 20-50 years old. The organs possibly involved, in order of decreasing frequency, are the lymph nodes, lungs, skin, eyes, and bones. In the practice of otolaryngology, the nose, tonsil, and larynx are sites of predilection. Localization of sarcoidosis in the respiratory tract and in the salivary gland happens in only about 3% of all cases. The most common opthalmic manifestations are iridocyclitis, keratitis, conjunctivitis, and episcleritis.

Uveoparotid fever of Heerfordt, a variant of sarcoidosis, is characterized by fever, parotid involvement, uveitis, and facial paralysis (usually bilateral and transient).

The frequency of hypercalcemia in sarcoidosis ranges from 3-20%, and for hyperglobulinaemia from 45-70%. Leukopenia is encountered quite frequently while eosinophilia occurs in 20% of the cases.

Pituitary Adenoma

The pituitary gland (hypophysis) has two divisions in the human. The anterior portion of the pituitary is called the adenohypophysis. Prolactin, growth hormone (GH), adrenocorticotrophic hormone (ACTH), thyroid-stimulating hormone (TSH), follicle- stimulating hormone (FSH), and luteinizing hormone (LH) are among the hormones released by the adenohypophysis. Release of all of these hormones is under the control of hypothalamic factors and/or hormones. The posterior portion of the pituitary gland is termed the neurohypophysis, and releases antidiuretic hormone (ADH or vasopressin) and oxytocin. Both of these hormones are actually formed in the supraoptic and paraventricular nuclei of the hypothalamus, from which they are transported via the portal venous system to the neurohypophysis for storage and ultimate release.

The cell types of the anterior pituitary gland by light microscopy include chromophobe cells (comprising 50% of the total cell population), acidophils (also termed alpha cells; accounting for 40% of the pituitary cells), and basophils (also called beta cells; making up 10% of the pituitary cell population). The glial cells of the neurohypophysis are termed pituicytes. The older method of classifying pituitary adenomas by light microscopy with the

4 standard hematoxylin-eosin staining - chromophobe, eosinophilic, or basophilic adenoma - is now not adequate in view of current findings through immunohistochemistry, electron microscopy, and serum hormone assays. Pituitary tumours are now classified as functional (hormone-secreting) or non-functional (non-hormone-secreting).

The differential diagnoses of sellar and parasellar lesions include the following:

1. Pituitary adenoma

a. Functional

1) Prolactin-secreting - most common.

2) Growth hormone (GH) secreting.

3) Adrenocorticotropin (ACTH) secreting.

4) Other, less common secreting tumors.

b. Nonfunctional.

2. Invasive, "malignant" pituitary adenoma - less than 3% of cases.

3. Pituitary apoplexy.

4. Meningioma: tuberculum sellae, diaphragma sellae, cavernous sinus, medial third of sphenoid wing.

5. Cranipharyngioma.

6. Metastatic neoplasms: breast, lung, prostate, etc.

7. Hypothalamus

a. Optic and/or hypothalamic glioma.

b. Hamartoma of the hypothalamus.

8. Epidermoid, dermoid, germinoma.

9. Chordoma, chondrosarcoma, osteochondroma.

10. Neurohypophyseal: infundibulum, granular cell myoblastoma.

11. Aneurysm.

12. Empty sella syndrome: may be primary or secondary, with or without enlarged third ventricle.

5 13. Inflammatory

a. Sellar abscess.

b. Mucocele of sphenoid sinus.

c. Granulomatous disease: sarcoidosis, tuberculosis.

Signs and symptoms of pituitary tumors may be placed into three groups:

Endocrine

Functional Tumours

Prolactinoma. This is the most common pituitary tumor. It is most frequently seen in young females; prolactinomas present with galactorrhea with or without amenorrhoea. The majority are microadenomas (10 mm or less in diameter). By light microscopy, most of these tumors are chromophobe adenomas.

Growth Hormone (GH) Secreting Adenomas. Gigantism may be seen in childhood cases before the epiphyses of the long bones have been closed. Acromegaly is seen in adults. Classically, these tumnors were described as eosinophilic adenomas. However, most cases are chromophobe adenomas by light microscopy. Growth hormone secreting tumors are the second most common of the endocrine active adenomas.

Adrenocorticotropin (ACTH) Secreting Adenomas. These present clinically as Cushing's disease. These tumors are usually microadenomas, and occur much less frequently than prolactinomas and growth hormone secreting tumors. They are more common symptomatically in females. Hyperpigmentation with increasing sellar size may be seen in Cushing's syndrome after bilateral adrenalectomy, and is known as Nelson's syndrome. ACTH-secreting tumors of Nelson's syndrome tend to be more aggressive and larger in size. Basophilic adenomas are usually demonstrated by light microscopy and hematoxylin-eosin staining techniques.

Nonfunctional Tumors

These neoplasms may present without endocrine deficiencies, or may present with decreased function of one or more hormones. In its most severe form, panhypopituitarism with visual symptoms with or without signs of increased intracranial pressure and/or extraocular muscle palsies may be seen.

Pituitary Adenomas

These tumors may occur as part of the syndrome of multiple endocrine adenomatosis. The majority of cases of Wermer's syndrome (multiple endocrine adenomatosis type I) are associated with pituitary tumors, as well as parathyroid, pancreas, adrenal, and/or thyroid tumors.

6 Visual Symptoms and Signs

The classic visual finding associated with enlarging suprasellar extension of pituitary adenomas is bitemporal hemianopsia associated with a progressive decrease in visual acuity.

If there is significant lateral extension of tumor growth toward the cavernous sinus, extraocular muscle palsies (cranial nerves III, IV, and/or VI) may be noted.

The syndrome of pituitary apoplexy may occasionally be seen in pituitary tumors. There is a sudden loss of vision associated with hemorrhage within a pituitary adenoma. Severe headache, decrease in level of sensorium, extraocular muscle palsies, and meningismus also may occur. Pituitary apoplexy is a relative emergency which particularly lends itself toward a transsphenoidal approach for removal of the hematom if a patient with this syndrome is seen relatively soon after the apoplectic episode.

Headache

Headache is a common symptom associated with pituitary adenomas. Initially, the headache may be due to pressure caused by growth of the tumor along the dural covering of the cavernous sinus and/or stretching of the dura of the diaphragm sellae. With further suprasellar extension of tumor, obstruction of the foramina of Monro may occur with associated hydrocephalus and increased intracranial pressure. This is usually a late development. Pituitary adenomas with only headache as a symptom usually are not diagnosed because headache is such a common, nonspecific symptom.

Diagnosis

Today, most functional pituitary adenomas are diagnosed as intrasellar lesions without signs of mass effect. Most endocrine inactive, nonfunctional tumors are not diagnosed until signs and symptoms of hypopituitarism or mass effect evolve. An asymptomatic enlarged sella turcica is occasionally noted on skull or sinus x-rays.

Transseptal, Transsphenoidal Approach to the Sella Turcica

Anatomically, the important features in regard to the sella turcica include the following:

1. Inferiorly, there is a dural covering over the pituitary gland.

2. Superiorly, the diaphragm sellae, through which the infundibulum of the pituitary passes, is located.

3. Anteriorly, the venous circular sinus is located within the dura.

4. Posteriorly, the dorsum sellae may be palpated on intrasellar exploration.

7 5. Located on either side laterally is the venous cavernous sinus, which contains the third, fourth, and sixth cranial nerves, as well as the first and second divisions of the fifth cranial nerve, and the internal carotid artery.

Preoperative Evaluation of Pituitary Tumors

The team approach is essential in evaluation of lesions in and adjacent to the pituitary gland. This should include the following:

1. Complete otolaryngologic evaluation, including examination of gums and teeth.

2. Complete neurologic examination.

3. Neuro-ophthalmologic examination.

4. Endocrinologic workup (as indicated below).

5. Neuroradiologic evaluation, including:

a. Skull x-rays.

b. Polytomography of the sphenoid sinus and sella turcica, including submentovertex views.

c. Computed tomography scan.

d. Arteriography - escpecially digital venous angiography - may be required for localization of the cavernous portion of the internal carotid artery, localization of the A-1 segment of the anterior cerebral artery, and/or to rule out an aneurysm.

e. Pneumoencephalography today is only rarely required.

6. Nose and throat culture and sensitivity.

7. Antibiotics as indicated. Usually penicillin is used, unless the preoperative nose and throat culture indicates a resistant organism, in which case an appropriate antibiotic according to sensitivity testing is used.

8. Preoperative and intraoperative steroids with continuance into the postoperative period.

Preoperative Endocrine Studies for Pituitary Adenomas

Complete endocrinologic evaluation is required for evaluation of pituitary adenomas. Endocrine studies should include serum cortisol (A.M. and P.M.), growth hormone (with concomitant serum glucose), prolacting, complete thyroid evaluation (including T3 uptake, T4, free T4), FSH, LH, and serum and urine electrolytes and osmolalities. In addition, further tests

8 such as insulin tolerance test (ITT), TRH stimulation, and glucose tolerance test (GTT) may be required. The normal values for these tests vary from laboratory to laboratory.

Postoperative Endocrine Care

Most cases undergoing pituitary surgery will have at least a transient diabetes insipidus. In a few cases this may be permanent, especially in cases undergoing total hypophysectomy for metastatic carcinoma of the breast. Hourly monitoring of urine output and specific gravity is required in the immediate postoperative period. In addition, close monitoring of serum and urine electrolytes and osmolalities is required. Acutely, one may assume that the patient has diabetes insipidus if there is prolonged urine output of greater than 250 mL/hr with a specific gravity of 1.005 or less. Therapy may initially include intravenous fluids at a rate to replace the previous hour's urinary output. However, if the volume of urinary output becomes too excessive and/or prolonged, one may give vasopressin (Pitressin). There are two types, as in-oil preparation and aqueous Pitressin. The latter has a shorter duration of action than the former and, in general, is preferred as the initial mode of therapy for diabetes insipidus if fluid replacement is not effective. In cases of chronic diabetes insipidus, intranasal desmopressin acetate (a synthetic analogue of vasopressin) may be required. Steroid and thyroid maintenance therapy may be required, especially in cases of preoperative panhypopytuitarism. In such instances a total of 37.5 mg of cortisone acetate and 2 gr of dessicated thyroid, or its equivalent (such as levothyroxine sodium 0.1-0.2 mg), each day will be sufficient. This dosage is required in hypophysectomy cases and in instances of pituitary adenoma presenting with hypopituitary function.

Rationale for Hypophysectomy in Patients with Carcinoma of the Breast

The indications for hypophysectomy in cases of carcinoma of the breast include that of (1) advanced disease with evidence of a previous objective response to endocrine manipulation and (2) intractable bone pain. If estrogen-binding factor is present in tumor tissue in appropriate cases, the chance for an objective response to hypophysectomy is greatly enhanced.

Differential Diagnosis of Cerebellopontine Angle Tumours

Acoustic Neuroma

Hearing loss (retrocochlear pattern) is an early symptom, usually associated with tinnitus. With a progressive increase in tumor size, involvement of the fifth (decreased corneal reflex, facial hypesthesia) and seventh (peripheral facial paresis) cranial nerves occurs. Further tumor growth may involve the cerebellum (gait ataxia, dysmetria, nystagmus, etc), brain stem (hemiparesis, Babinski's response, etc), and/or jugular foramen (ninth, tenth, and eleventh cranial nerves). Bilateral acoustic neuromas may be seen in von Recklinghausen's disease.

X-rays, including skull films, Stenvers' views and polytomography of the internal auditory meatus usually reveal enlargement of this structure. Computed tomography (CT) scanning is positive in most larger tumors (greater than 1 cm in diameter) in the cerebellopontine angle. These tumors tend to be clearly demarcated masses whose tissue density may be close to neural tissue. Usually, significant contrast enhancement is present.

9 Smaller lesions, including some intracanalicular acoustic neuromas, may be seen on more recent CT scanners, such as the GE model 8800. Computer tomography scanning has antiquated the use of older studies, such as brain scanning and pneumoencephalography.

Cerebellopontine angle myelography is indicated for smaller lesions - particularly intracanalicular lesions - even if CT scanning is negative, if an appropriate history and clinical findings (including audiometry) are suggestive of an acoustic neuroma. In such cases, nonfiling of the internal auditory meatus and/or outlining of an intracanalicular lesion are noted. Cerebrospinal fluid protein often is elevated. Either metrizimide or Pantopaque may be used as a contrast media. Metrizamide has the advantage of being water soluble (and thus does not have to be removed at the end of the procedure) and also may be used with concomitant CT scanning for brain stem and/or cerebellopontine angle cisternography evaluation. Headache, nausea, and vomiting are the most common side effects of metrizamide. Seizures are also a risk with metrizamide, and this dye should not be used in patients with a past history of seizure disorder or patients who are on phenothiazines.

Angiography may reveal displacement of the anterior inferior cerebellar artery and/or petrosal vein, as well as other vascular displacement in larger tumors.

Meningioma

This is the second most common primary cerebellopontine angle mass lesion. Hearing loss tends to occur later in the clinical course of these lesions as compared with acoustic neuromas. Multiple cranial nerve palsies, brain stem, and cerebellar signs may be present with further tumor growth.

X-rays may reveal abnormal calcification and/or local hyperostosis involving the petrous ridge, but the internal auditory meatus will be normal in size.

Computed tomography scanning is nearly always positive in these lesions, exhibiting significant contrast enhancement.

Cerebellopontine angle myelography, if performed, reveals nonfilling of the cerebellopontine angle.

Angiography will reveal local vessel displacement. Tumor stain also may be seen (usually not present in acoustic neuromas).

Epidermoid

This is the third most common primary cerebellopontine angle mass lesion. Hearing loss, if present, tends to occur late in the patient's clinical course. Multiple cranial nerve palsies, with or without brain stem and/or cerebellar signs, may be found.

Plain skull films and laminagrams are usually within normal limits. The internal auditory meatus is normal in size.

10 Computed tomography scanning may reveal a low-density lesion in the region of the cerebellopontine angle which does not exhibit cotrast enhancement.

Cerebellopontine angle myelography, if performed, reveals an irregular angle mass lesion with contrast material irregularly filling the interstices of the tumor.

Pneumoencephalography usually is not performed currently. If performed, this study may be diagnostic, revealing air filling the fingerlike interstices of an angle mass lesion. Cerebrospinal fluid protein may be elevated.

Angiography may reveal local vascular displacement without tumor stain.

Metastatic Neoplasm

Metastatic tumors (lung, breast, etc) have a more rapid clinical course than the first three diagnostic possibilities. Multiple, bilateral lower (and upper) cranial nerve palsies usually evolve as a manifestation of meningeal carcinomatosis. Most often a previous history of neoplasia is obtained. Evidence of metastatic disease elsewhere often is present. Plain skull films and polytomography of the internal auditory meatus are normal.

Computed tomography scanning is usually positive with contrast enhancement in larger lesions. Multiple lesions elsewhere intracranially may be diagnosed. In the initial phase of meningeal carcinomatosis, the CT scan may be negative.

Cerebellopontine angle myelography usually is not performed. Cerebrospinal fluid protein may be elevated and tumor cells may be noted on cerebrospinal fluid cell cytology analysis.

Angiography usually is not required. If it is performed, local vascular displacement with or without a tumor stain may be noted.

Glioma

Occasionally brain stem or cerebellar gliomas (astrocytoma, subependymoma, etc) may "escape" into the subarachnoid space and grow out toward the cerebellopontine angle. Such patients may present with symptoms of a lesion in this area. Examination may reveal a predominantly brain stem or cerebellar lesion. Plain x-rays are usually normal.

Computed tomography usually will reveal a cerebellar and/or brain stem glioma. Contrast enhancement is commonly seen. Metrizamide cisternography with CT scanning may be quite helpful in revealing brain steam asymmetry in questionable brain stem lesions. Angiography may reveal local vascular displacement, with or without a tumor stain. Despite the above noted findings, on occasion the diagnosis may be unsuspected and made only at the time of surgery.

11 Aneurysms and Other Lesions

Aneurysms, if large enough, may be suggested on CT scanning. The definitive diagnosis is made by angiography. Chordoma and other bony lesions may be diagnosed by appropriate x-rays, including polytomography, and CT scanning. Angiography may reveal an avascular mass.

Miscellaneous

1. Parosmia: perverted sense of smell.

Hyperosmia: oversensitive sense of smell.

Hyposmia: impaired sense of smell.

Anosmia: total loss of smell.

Cacosmia: a sense of foul smell when none is present.

2. Diphenylhydantoin (Dilantin) and carbamazepine (Tegretol) have been used to treat trigeminal neuralgia.

3. Vitamin A has been used to treat anosmia (se Chap. 14).

4. Ammonia stimulates cranial nerve V and not the cranial nerve I. Hence, it can be used when a psychogenic cause of anosmia is suspected.

12 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 31: Fluids, Electrolytes, and Acid-Base Balance

Part I

Critical disturbances in the fluid, electrolyte, or acid-base balance of the body may have no outward signs or symptoms and only diagnosed by laboratory testing. It is important to note that the body will try to maintain volume at the expense of osmolarity, electrolytes, or pH. Nonspecific signs such as somnolence, confusion, or weakness may be the only hints of an underlying abnormality.

The otolaryngolic patient is particularly prone to such disturbances because of the effects of anaesthesia, parenteral feeding, and underlying medical diseases such as diabetes, heart failure, or diuretic therapy. The following lists and tables review some of these disturbances. Therapy must be individualized based on all underlying conditions and their pathophysiology.

Nonspecific Signs of Fluid, Electrolyte, or Acid-Base Disturbances

Confusion Muscle weaknes Delirium Hyperventilation Hallucinations Hypoventilation Coma Arrhythmias Seizures Abnormal reflexes Lethargy

Signs of Fluid Disturbances

Overhydration

Polyuria Ascites Urine sodium > 30 mEq/L Peripheral edema Pulmonary edema Systolic hypertension Distended neck veins Elevated wedge pressure

Dehydration

Oliguria Thirst Urine sodium < 10 mEq/L Tachycardia Hypotension Hemoconcentration Poor skin turgor Low wedge pressure Sunken eyeballs

1 Hyperkalaemia

Cause

Potassium-sparing diurectics Hypoaldosteronism - especially in diabetics Crush injury Renal failure Increased intake (salt substitutes) Acidosis Prostaglandin inhibitors

Therapy

Decrease intake Calcium gluconate: 1 ampule (10 mL = 940 mg) IVq2hr Glucose: 50 mL 50% dextrose plus insulin (crystalline zinc) 10 IU IV/SC Sodium bicarbonate: 1.2 g TID PO or 1 ampule IVq4hrtokeep bicarbonate level > 25 mEq/L Loop diuretics: 40-80 mg furosemide (Lasix) or 50-100 mg ethacrynic acid (Edecrin) IV or PO. Do not use potassium-sparing diuretics such as spironolactone (Aldactone), hydrochlorthiazide and triamterene (Dyazide), or amiloride (Moduretic or Midamor). Exchange resins: 25-50 mg sodium polystyrene sulfanate (Kayexelate) PO or by enema 2-3 times a day Mineralocorticosteroids 0.1 mg fludrocortisone (Florinet) PO q 24 hr Dialysis: peritoneal or hemodialysis.

Table 31-1. Hyponatremia (Signs Are Those of Associated Fluid Status)

Pathogenesis Volume Status Etiology Therapy

Loss of sodium in excess of body water Volume depletion Renal losses: diuretics, nephritis, osmotic diuresis Normal saline: ± 1 L IV q 4-6 hr if cardiac status satisfactory Extra-renal losses: vomiting, diarrhea, thrid-space losses Normal saline: ± 1 L IV q 4-6 hr if cardiac status satisfactory

Excess water Slight overhydration Addison's disease - Steroids Myxedema - Thyroxine

2 Inappropriate anti-diuretic syndrome 1. Fluid restriction (1 L/24 hr) 2. Hypertonic saline 300 mL of 3% saline over 4 hr 3. Loop diuretics 4. Dilantin 100 mg t.i.d. 5. Lithium 300 mg p.o. q.i.d. 6. Demeclocycline 300 mg q.i.d.

Excess sodium and excess water Overhydration with edema Congestive heart lung 1. Fluid restriction Nephrosis 2. Diuretics Cirrhosis Lasix 40-100 mg IV q 12-24 hr Renal failure Edecrin 50-100 mg IV q 12-24 hr.

Table 31-2. Causes of Hypernatremia

Therapy depends on fluid status and must be individualized. One should calculate the fluid deficit and replace fluids gradually over 1-2 days to avoid cerebral edema or congestive heart failure. Specific therapy must then be directed at the underlying condition.

Water loss in excess of sodium loss

Central or nephrogenic diabetes insipidus Vomiting Diarrhea Severe burns Osmotic diuresis (calcium, glucose, IVP dye) Excessive insensible losses

Inadequate water intake

Hypothalamic disease Stupor

Administration of sodium in excess of water

Excessive salt ingestion IV or p.o. Dialysis

Sodium retention Cushing's syndrome Hyperaldosteronism

3 Loss of renal concentration ability

Uremia Hypokalemia Lithium therapy Methoxyflurane anesthesia Sickle cell anemia Multiple myeloma Hypercalcemia.

Hypocalcemia

Causes

Hypoparathyroidism: iatrogenic, idiopathic. Pseudohypoparathyroidism Pancreatitis Renal failure Hypomagnesemia Vitamin D deficiency Malabsorption Hypoalbuminemia (does not need therapy).

Therapy

1. Acute therapy: 10 mL of 10% calcium chloride or calcium gluconate IV repeat of 8-12 hr as needed.

2. Chronic therapy: (a) calcium 1 g p.o. t.i.d.

(b) Vitamin D 50.000 units, or Dihydrotachysterol 0.125 mg to 0.4 mg/day

(c) Magnesium (if deficient) 2 mL magnesium sulphate IM p.r.n.

Table 31-3. Hypercalcemia

Causes

Hyperparathyroidism Ectopic parathyroid hormone secretion Bony metastases Milk alkali syndrome Vitamin D toxicity Sarcoid Tuberculosis

Therapy (to be individualized)

4 1. Parathyroidectomy 2. Hydration: oral fluids as tolerated 3. Saline 1-2 L IV q 2-4 hr (watch cardiac status) 4. Loop diuretics Lasix 40 mg, Edecrin 50 mg IV or p.o. 5. Phosphate 250-500 mg p.o.q6hr(asNeutra-Phos) 6. Steroids 100 mg Solu-Cortef IVq8hror25mgcortisone acet.q6hr 7. Mithramycin 15-25 microg/kg IV q 24-48 hr 9. Indomethacin 25 mg p.o.q6hr.

Table 31-4. Acid-Base Disturbances

Disturbance pH Hydrogen ion pCO2 bicarbonate

Metabolic acidosis low high low low* Metabolic alkalosis high low high high* Respiratory acidosis low high high* high Respiratory alkalosis high low low* low

Normal range 7.35-7.45 36-45 mEq/L 35-45 mmHg 22-26 mEq/L.

* Primary abnormality.

Causes of Metabolic Alkalosis

Diuretics Vomiting Diarrhea Antacid therapy Hyperladosteronism Gastrointestinal fistula.

Therapy

Potassium chloride to maintain K level above 3.5 mEq/L, fluids, carbonic anhydrase inhibitors (acetazolamide - Diamox - 250 mg p.o. q.i.d.). Treat underlying condition.

Causes of Respiratory Acidosis Acute General anesthesia Cardiac arrest Sedation Pulmonary edema Severe pneumonia Bronchospasm Laryngospasm Foreign body aspiration Mechanical ventilation.

5 Chronic

Alveolar hypoventilation Obstructive pulmonary disease Brain tumor Respiratory muscle weakness or nerve damage Restrictive lung disease.

Therapy

Directed at improving respiratory gas exchange.

Causes of Respiratory Alkalosis

(Produced by hyperventilation)

Anxiety Hysteria Oain Fever Salicylate intoxication Stroke CNS trauma, infection, tumor. Congestive heart failure Pneumonia Hypoxia Hepatic insufficiency Gram-negative sepsis Mechanical ventilators.

Therapy

Treat underlying condition, increase "dead space" if on ventilator.

Causes of Metabolic Acidosis

Increased Anion Gap

Increased Organic Acid Production lactic acidosis diabetic ketoacidosis starvation ketosis alcoholic ketoacidosis

6 Inability to Excrete Inorganic Acids chronic renal failure acute renal failure

Ingestion of Exogenous Acids salicylates methanol paraldehide ethylene glycol

Normal Anion Gap

Loss of Bicarbonate

GI tract loss ureterosigmoidostomy renal tubular acidosis uremia (early) carbonic anhydrase inhibitor therapy hypoaldosteronism corection of chronic respiratory alkalosis

Chloride Therapy hyperalimentation ammonium chloride lysine hydrochloride arginine hydrochloride

Administration of Acids with Rapid Renal Clearances of Unmeasured Ions sulfuric acid phosphoric acid sulfur containing amino acids.

Therapy

Bicarbonate therapy to raise pH above 7.3-7.35 and treat underlying abnormality.

Electrocardiographic Abnormalities of Electrolyte Abnormalities

Hyperkalemia Peaked T wave Prolonged QRS Sinus arrest Ventricular sine wave

7 Hypokalemia

Prolonged QT interval ST segment depression U waves

Hypocalcemia

Lengthened QT segment (Normal T wave duration)

Hypercalcemia

Shortened QT interval.

8 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 32: Fluids, Electrolytes, and Acid-Base Balance

Part II

Body Fluids

The total fluid content of the human can be estimated on the basis of 60-70% of the body weight. The intracellular water represents 40-50% of the total weight. The circulatory blood volume may be estimated as 7% of the body weight in normal man and 6.5% in women. Thus in a 70 kg man the various estimated volumes are:

Blood volume: 4.9 L Intracellular volume: 32 L Total body water: 49 L

The maintenance of a normal circulating blood volume is all-important to maintain the normal function of the heart as a pump and deliver adequate blood and nutrients to all organs but particularly to the lungs and kidneys for their regulatory functions.

Hypovolemia or decreased circulating blood volume may be recognized clinically by:

1. Decreased urinary output: less than 30 mL/hr with an increased specific gravity of the urine.

2. Low central venous pressure: 0-5 cm H2O 3. Increased pulse rate. Pulse may be soft and thready. 4. Decreasing systolic blood pressure. 5. Thirst and dry skin as it becomes well established.

The ill effects of the hypovolemic state are related to the lack of circulation to all systems but impairment of cardiac function and the development of metabolic acidosis are of greatest concern. Impaired tissue perfusion causes anaerobic metabolism of carbohydrates with formation of lactic acid and increased acidosis. Acute hypovolemic states also may precipitate acute tubular necrosis of the kidney.

The ideal treatment of the hypovolemic state is the replacement of the fluid that has been lost - not only in quantity but in quality. If hemorrhage is responsible then whole blood should be replaced. Other fluid losses should be replaced with solutions of similar electrolyte content. The speed of such replacement depends on the need.

Hypervolemia or increased circulating blood volume may be recognized by:

1. Increased urinary output of a dilute urine. 2. High central venous pressure: azbove 15 cm and rising. 3. Ascites, basal pulmonary rales, and peripheral edema. 4. Distended neck veins. 5. Bounding pulse, increased cardiac rate, and blood pressure.

1 The ill effects of the hypervolemia are related primarily to the overloading of the heart with precipitation of heart failure and pulmonary edema. The local edema in operative wounds is undesirable because of impairment of healing and increased infection.

Treatment plans are adjusted on the apparent need to correct the overload. Simple withdrawal of intake may be sufficient but the use of diuretics, digitalization, and phlebotomy may be indicated.

Major Electrolytes in Body Fluids

The electrolyte content of the intracellular and extracellular fluids are shown in Table 32-1.

The osmolality of the serum is an expression of the osmotic pressure capability of the ionic constituents of the serum and/or extracellular fluid generated against cell membranes. It is dependent primarily on the sodium ions and the anions chloride and bicarbonate which accompany it with a significantly lesser contribution by glucose and protein. The urea diffuses so freely that it contributes very little to osmotic pressure. The normal osmolality of serum is about 285 mOsm/L. The sodium ions provide about one-half. The body regulatory mechanisms adjust to control the serum osmolality and not the level of serum sodium.

Table 32-1. Major Body Fluid Electrolytes

Substance Extracellular Fluid (mEq/L) Intracellular Fluid (mEq/L)

Sodium 140 10 Potassium 4 150 Magnesium 1.7 40 Chloride 105 10 Bicarbonate 28 10 Phosphate and sulfate 3.5 150 Protein anions 15 40

The composition of the intracellular fluids is quite different. The greatest ionic effect is provided by the high potassium and magnesium concentrations. The main anions within the cells are phosphate, sulfate, and protein.

For all practical purposes the body cells maintain perfect osmotic balance between the intracellular and extracellular fluids at all times. Hypoosmolality may be produced by either sodium depletion, potassium depletion, or excess of water, or a combination of the three. Hyperosmolality is produced by sodium or potassium excces or by body water depletion.

The control of the osmolality of the serum is accomplished by several factors. The intake and output of water is under CNS control. A small increase in the concentration stimulates the thirst center as well as production of antidiuretic hormone (ADH). The ADH acts on the distal tubules of the kidney causing water to be reabsorbed thus producing maximally concentrated urine. Fluid loss also occurs in sweating, via the lungs and gastrointestinal tract.

2 Sodium

The control of sodium loss through the kidney is another powerful mechanism. The variation in the amount of sodium filtered through the glomerulus is influenced greatly by many factors, particularly circulatory factors. The resorption of the sodium in the distal tubule is controlled by the hormone aldosterone from the adrenal glands. The aldosterone causes the cells of the distal tubule to conserve the sodium and excrete potassium. Although the body constantly secretes some aldosterone in a circadian rhythm the known stimuli include:

1. Changes in extracellular fluid volume including acute hemorrhage.

2. Diets low in sodium or high in potassium.

3. Acute heat stress.

Hyponatremia may develop with the followig clinical derangements:

1. Loss from the gastrointestinal tract with vomiting, diarrhea, and fistulae. Excessive water loss also occurs.

2. Starvation states including prolonged surgical illness.

3. Cardiac, hepatic, and renal diseases in which there is overexpanded extracellular fluid volume:

a. Right-sided heart failure

b. Cirrhosis of the liver with portal hypertension

c. Nephrotic syndrome

4. Acute tubular necrosis or other renal states in which excess fluid has been given to encourage renal output.

5. Inappropriate secretion of antidiuretic hormone after major surgical operations.

6. Certain malignant tumors produce antidiuretic hormone resulting in water retention and sodium dilution.

Hypernatremia may occur under the following conditions:

1. Stuporous patient fails to take sufficient water.

2. Inadequate or inappropriate water replacement after operation. Solutions with a high salt content given by tube feeding or intravenously may increase the obligatory urinary loss.

3. Renal disease states in which there is abnormal water loss.

3 Potassium

Most of the body potassium is intracellular, only about 75 mEq being in the extracellular fluid. The normal range in the plasma is 3.5-4.8 mEq/L. Daily urinary losses of 50 mEq are usual. The required intake averages 50-60 mEq/day. Unfortunately, the plasma concentration does not give an accurate reflection of the intracellular concentration, but is the best available for clinical use.

The greatest clinical effect of hypokalemia is muscle weakness. All muscles are affected, the myocardial most severely and the respiratory muscles minimally. The involvement of the intestinal musculature may be clinically manifested by gastric dilatation of paralytic ileus. Renal damage may occur with prolonged depletion. This is manifested by the inability of the kidney to concentrate urine by the absorption of water - tubular cells having been damaged.

Hyperkalemia is life threatening by its action on the heart. Muscle cells are depolarized and serious impairment of the conductive tissue results. There is a sudden onset of ventricular fibrillation. The heart stops in diastole. The voluntary muscles of the extremities may become painful and weak.

Common Causes of Hypokalemia

1. Abnormal loss of gastrointestinal fluids: vomiting, aspiration, diarrhea, fistula, disease with ulceration, or malabsorption.

2. Loss of fluids in burns or other large granulating wounds.

3. Excessive urinary loss: many renal diseases, hyperaldosteronism, alkalosis, and diuretics.

4. Metabolic disorders such as diabetes mellitus, starvation, and severe trauma.

Causes of Hyperkalemia

1. Renal failure

2. Rapid hemolysis of red blood cells as in hemolytic crisis

3. Dehydration: particularly with acidosis of diabetes

4. Adrenal failure: lack of aldosterone secretion.

Chloride Anion

The chloride in the body is the predominant anion in the extracellular fluid. The plasma chloride level is normally between 100-106 mEq/L. Most of the chloride is in the extracellular fluid. The plasma concentration is obviously affected by the state of hydration and a high concentration may be due to water loss only. The primary role of the chloride

4 anion seems to be related to the acid-base regulation exercised by the kidneys. Depending on the metabolic state and in order to have electrical neutrality the cations excreted in the urine must be balanced by anions, mainly chloride, bicarbonate, and phosphate. Thus in a state of alkalosis with a high bicarbonate, the urinary loss of chloride will be reduced and the bicarbonate loss increased. This is one of the main methods of control of pH of the blood.

The disease state resulting from the derangement of chloride concentration is invariably associated with other related metabolic problems: acute dehydration, hypokalemia, hyponatremia, etc. Symptoms or physiologic changes cannot be attributed to the abnormality of the chloride only.

Hypochloremia occurs frequently in surgical patients with:

1. An excess of water without loss of chloride due to action of antidiuretic hormone after operation or similar stress.

2. Abnormal loss of fluid from the gastrointestinal tract: vomiting, diarrhea, fistulae, etc.

3. Renal losses: diuretics, kidney disease.

4. Chronic respiratory acidosis.

Hyperchloremia is a relatively uncommon clinical problem due to:

1. All forms of excessive water loss.

2. Operative procedure for urinary diversion into the colon. The resorption of the sodium and chloride results in hyperchloremic acidosis.

3. Administration of ammonium chloride to acidify the urine.

Acid-Base Balance

The extracellular fluids are maintained at a pH of 7.4 or in close range thereto. This figure represents the hydrogen ion concentration or the acid ion in the balance. When there is neutrality in water the hydrogen ion concentration is 10-6.8 the same as the concentration of OH-. The pH designation refers to minus the log of the hydrogen ion concentration; thus pH is 6.8 at neutrality. The plasma pH of 7.4 means that the base is slightly in excess. In plasma the predominant bases are chloride and bicarbonate ions. Phosphate and protein ions are bases of lesser importance. Bicarbonate, phosphate, and proteinate anions are buffer bases since they can modulate the effects of an increase in hydrogen ions by removing them from solution.

The measurement of the respiratory component of the acid-base balance is best

accomplished by measuring the pCO2 of plasma. A rise means that the carbon dioxide is not being cleared adequately by the lungs and a fall indicates excess removal. It may be complicated when metabolic changes also occur but it remains the best evaluation.

5 The kidney controls the concentration of the acids other than carbonic acid which is eliminated through the respiratory tract. The other acids are, for the most part, metabolic products of all types of food. The kidney eliminates these products by various metabolic and excretory functions. Table 32-2 indicates the fluctuations that occur with various forms of acid-base imbalance.

Respiratory Alkalosis

This occurs as a result of excessive ventilation. The pCO2 is low. It may be caused by:

1. Overbreathing: either voluntary or involuntary.

2. Involuntary excessive respiratory exchange: exceesive blood ammonia or lesions of the central nervous system may stimulate the respiratory center.

If the compensatory mechanism does not operate quickly enough the pH will rise and symptoms of tetany will develop.

Respiratory Acidosis

This results as a result of subnormal respiration. The blood pH is either low or normal if compensated. It may be caused by:

1. Parenchymal disease of the lungs interfering with gaseous exchange.

2. Impairment of respiratory movements: as with drugs, muscle paralysis, fixation of chest wall by disease, chest wall trauma.

3. Deficient circulation through the lung by cardiovascular failure, embolism.

4. Inadequate respiratory exchange under anesthesia particularly with high oxygen concentration.

The ill effects of acidosis are primarily cardiac arrhythmias, increased susceptibility to shock, and increased vulnerability to drugs.

Table 32-2. Acid-Base Disturbances

pH PCO2 Bicarbonate Rx

Metabolic acidosis low low low Bicarbonate, ventilate Metabolic alkalosis high high high Tromethamine (THAM) Respiratory acidosis low high high Tracheostomy

Respiratory alkalosis high low low 5% CO2

6 Metabolic Alkalosis

This commonly occurs with:

1. Loss of chloride in prolonged vomiting, gastrointestinal fistulae, diarrhea.

2. Diuretics, particularly mercurials and chlorothiazide.

3. Excessive potassium loss with large bowel tumors.

4. Alkali overdosage as in ulcer therapy.

The significant loss of potassium which frequently accompanies the chloride loss is the chief concern of this metabolic state. The dehydration also may be of significance.

Metabolic Acidosis

This is one of the most common and serious derangements in the surgical patient. Frequent causes include:

1. Low blood flow with impaired tissue perfusion: shock, cardiac decompensation, hypovolemia.

2. Renal failure.

3. Diabetes mellitus.

The various metabolic processes produce acidosis which under normal conditions may be buffered and eliminated. With poor tissue perfusion anaerobic metabolism of carbohydrate produces an excess of lactic acid adding to the acid load which must be buffered by the bicarbonate buffer system. The lungs cannot remove the other acids produced in normal or abnormal metabolism. Only the normal kidney can effectively offer a complete control or resolution of metabolic acidosis.

The ill effects of the acidosis are the same whether the origin is respiratory or metabolic.

7 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 33: Surgical Hemostasis

Excessive surgical bleeding can result from vascular injury or may be secondary to a defect in the hemostatic mechanism. If damage to local tissue or vascular integrity is not the apparent cause for excessive bleeding, then such patients should be evaluated for a defect in platelets or the blood coagulation process. It is a mistake to assume that all patients with bleeding and a local anatomic defect do not also have an undetected bleeding disorder. Therefore, all bleeding patients should be screened for the common bleeding disorders. Likewise, all patients in whom surgery is anticipated should undergo a similar screening evaluation for clinically undetected bleeding disorders.

Hemostasis results from a complex interaction of plasma coagulation factors, platelets, and blood vessels. Tissue injury results in vasoconstriction, exposure of the blood to collagen and connective tissue, as well as to the procoagulant thromboplastin. Thromboplastin or tissue factor causes activation of the coagulation system through what is known as the extrinsic system. Through a final common pathway fibrin is formed. Simultaneously, platelets begin to adhere to exposed collagen. Once this happens, platelets aggregate, release ADP, and form the platelet plug. The release of phospholipids from platelets, as well as the formation of fibrin, triggers the more complex intrinsic coagulation system with continued formation of the fibrin net. Figure 33-1 shows a simplified coagulation cascade. Adequate functional levels of coagulation factors are necessary for the formation of a fibrin clot. In addition, adequate numbers of functioning platelets are necessary for hemostasis by both plugging blood vessel holes and by providing phospholipids necessary for the coagulation cascade.

Clinical Evaluation of the Bleeding Patient

In the patient who is bleeding, it must be determined if the problem is a local one alone or if it is related to a defect in the hemostatic system. A careful history and physical examination in conjunction with several screening laboratory tests will usually clarify this problem and indicatge whether it is congenital or acquired. A history of easy bruisability, spontaneous bleeding, especially from mucous membranes, and excessive bleeding after trauma, all suggest either an acquired or congenital bleeding disorder. A family history of bleeding suggests an inherited coagulation disorder such as hemophilia or von Willebrand's disease. For example, the description of bleeding following a dental extraction may be an important clue to a bleeding disorder. Normal patients typically bleed for up to 12 hours after a dental extraction and may have some slight oozing for an additional 1-2 days. Patients with platelet disorders usually have immediate and chronic bleeding while patients with disorders of blood coagulation typically have delayed bleeding. The phenomenon of delayed bleeding in patients with coagulation defects may be explained by the fact that these patients form a normal platelet plug which prevents immediate bleeding following a dental extraction. However, an inadequate coagulation system will allow bleeding to restart after 1-8 days. Therefore, bleeding occurring later than 3 days after surgery should alert one to the possibility of a secondary hemorrhagic diathesis. Physical examination may reveal petechiae suggesting a platelet disorder or significant bruising (especially greater than 6 cm) suggesting a coagulation defect. Bleeding from multiple sites is seen with disseminated intravascular coagulation with defibrination.

1 Laboratory Evaluation

The most common tests used to evaluate the hemostatic and coagulation systems are outlined below. Table 33-1 summarizes the relationship between different bleeding disorders and specific laboratory abnormalities.

Screening Tests

Platelet Count

The platelet count is a measurement of the number of circulating platelets. The normal platelet count is 150.000-350.000/mm3. A platelet estimate is usually adequate and is obtained from evaluation of the peripheral blood smear by an experienced technician. A formal platelet count is more accurate and should be done when an exact platelet count is needed.

Prothrombin Time (PT)

This test evaluates the extrinsic coagulation system as well as the final common pathway. The test is prolonged secondarily to hereditary deficiencies of Factors V, VII, X, prothrombin, and fibrinogen. It is most frequently abnormal with acquired disorders of coagulation such as vitamin K deficiency, warfarin (Coumadin) ingestion, liver disease, and disseminated intravascular coagulation.

Activated Partial Thromboplastin Time (PTT)

This test evaluates all of the coagulation factors in the intrinsic coagulation system and final common pathway. The PTT is prolonged by reduced levels of Factors VIII, IX, XI, and XII. To a lesser extent, it also is affected by defects in the final common pathway. Heparin prolongs the PTT by its antithrombin action and this test is a useful monitor of heparin activity. Mixing studies using equal parts of normal plasm and the patient's plasma may help to determine whether prolongation of the PTT is secondary to a coagulation factor deficiency or a circulating anticoagulant.

Additional Tests

Bleeding Time

This test specifically evaluates platelet function. The bleeding time will be prolonged if the platelet count falls below 100.000 or when there is a defect in platelet function. The normal value for the modified Ivy bleeding time is 2.5-10 minutes with a mean of 5 minutes. Despite a normal platelet count, certain drugs such as aspirin and the nonsteroidal anti- inflammatory drugs will prolong the bleeding time by affecting platelet function. This test is also abnormal in uremia and in von Willebrand's disease.

2 Platelet Aggregation Studies

These tests further define platelet function and may be abnormal with both congenital and acquired platelet function disorders. They are useful in separating out the different problems that can prolong a bleeding time.

Fibrinogen Level

Low levels of fibrinogen may be seen with disseminated intravascular coagulation, fibrinolysis, and a severe liver disease.

Thrombin Time

This test measures clot formation when thrombin is added to plasma. It is prolonged in clinical states manifesting very low levels of fibrinogen. It also is prolonged by elevated levels of fibrin degradation products, disseminated intravascular coagulation (DIC), and with heparin use.

Fibrin Degradation Products

These are circulating fragments of fibrin or fibrinogen. They are typically increased with liver disease, DIC, and fibrinolysis.

Specific Coagulation Factor Assays

The measurement of plasma levels of specific coagulation factors can be obtained. These assays can help to define specific coagulation factor deficiencies.

The platelet count, PT, and PTT are used as initial screening tests. A prolonged PTT will detect most patients (greater than 90%) with hereditary coagulation factor deficiencies while a prolongation of the PT usually suggests an acquired disorder of coagulation such as vitamin K deficiency or DIC. These tests will be normal in patients with vascular abnormalities such as hereditary hemorrhagic telangiectasia, senile purpura, cryoglobulinemia, and allergic purpura. The PT and PTT may be prolonged secondary to improperly collected and stored blood samples, and abnormal results should always be repeated. Unfortunately, some patients with mild coagulation factor deficiencies or with mild von Willebrand's disease who have significant bleeding may have normal screening tests.

Patients with no bleeding history and normal screening tests are assumed to have no bleeding problem. Alternatively, a defect in hemostasis can be assured if abnormal screening tests are associated with a history of abnormal bleeding. The most difficult patients to evaluate are those in whom there is a history suggestive of abnormal bleeding but the primary screening tests are normal. Such patients need further evaluation especially if surgery is contemplated. Mild coagulation factor deficiencies and von Willebrand's disease may fall into this group. Additional studies that might be done are a bleeding time, specific coagulation factor assays, and platelet aggregation studies. The latter test is especially important if the bleeding time is found to be prolonged as is typically the case in von Willebrand's disease.

3 It should be remembered that a clear-cut history of bleeding may be more significant than a normal laboratory evaluation.

Specific Hemostatic and Coagulation Abnormalities

Platelet Abnormalities

Normally, platelet counts range between 150.000-350.000/mm3. In addition to a low platelet count, defects in platelet function or extraordinarily high platelet counts may all be associated with bleeding. Bleeding secondary to platelet disorders is usually small-vessel bleeding, and one frequently sees petechial hemorrhages on the skin and mucous membranes. A low platelet count or abnormal platelet function will prolong the bleeding time, and this test is therefore useful in the evaluation of platelet function.

Thrombocytopenia

Thrombocytopenia is the most common cause of abnormal bleeding. While spontaneous bleeding typically is not seen until the platelet count falls below 20.000/m3, platelet levels below 100.000/mm3 can cause bleeding during surgery (assuming platelet function is normal). A low platelet count may be secondary to reduced platelet production as seen with bone marrow infiltrative processes, ineffective thrombopoiesis as in megaloblastic defects (vitamin B12 or folic acid deficiency), primary disorders of the bone marrow, and by hematopoietic suppression secondary to drugs. Increased destruction of platelets as seen with idiopathic thrombocytopenic purpura (ITP), drug allergy, hypersplenism, and DIC also cause a reduction in the number of circulating platelets. Bleeding is typically more severe in disorders caused by decreased platelet production. Syndromes associated with increased platelet destruction are accompanied by younger circulating platelets which are homeostatically most effective. Older functionally senescent platelets predominate in the circulation of patients with decreased platelet production. A bone marrow aspiration is required to evaluate thrombocytopenia since the number of megakaryocytes may suggest either decreased platelet production or increased destruction as the cause for the thrombocytopenia.

Another significant and important cause of thrombocytopenia is platelet loss. This should be looked for in a bleeding patient who has received more than 10 units of red cells, since banked red cells do not contain significant numbers of viable platelets. Thrombocytopenia is treated by the administration of platelet concentrates.

Platelet transfusions should be given prophylactically to patients with platelet counts less than 20.000/mm3, especially when the thrombocytopenia is caused by reduced platelet production. All patients with hemorrhage and thrombocytopenia also should be given platelet transfusions though they may not be of value if the thrombocytopenia is secondary to accelerated platelet destruction as is the case with immune thrombocytopenia.

Qualitative Platelet Disorders

Abnormal platelet function also may cause bleeding. A normal platelet count in the presence of a prolonged bleeding time suggests platelet dysfunction. Platelet aggregation

4 studies are available in many hospitals to further evaluate this problem. Although congenital defects in platelet function are rare, acquired defects in platelet function are not uncommon. This may result from the ingestion of drugs such as aspirin and the non-steroidal anti- inflammatory agents. Other causes of platelet dysfunction include uremia, the myeloproliferative disorders, and paraproteinemias. Treatment may be with the transfusion of platelet concentrates or by the removal of the offending agent.

Thrombocytosis

Bleeding also may become a problem if the platelet count rises above 1 million/mm3 especially when this occurs secondary to a myeloproliferative disorder. Treatment is directed toward the underlying cause of the thrombocytosis. Occasionally, however, in an emergency situation, plateletpheresis can be done.

Coagulation Factor Deficiencies

The most common hereditary coagulation factor deficiencies are typically associated with a prolongation of the PTT. Von Willebrand's disease is the most common of these disorders followed by hemophilia A (Factor VIII deficiency), Factor IX, and Factor XI deficiency. Together these four disorders comprise greater than 90% of the congenital coagulation factor deficiencies. Other hereditary coagulation factor deficiencies are quite rare and will be mentioned only for completeness. Rarely, patients develop acquired deficiencies of coagulation factors, usually secondary to an underlying immunologic disorder.

There is no difficulty in diagnosing the patient with a severe hereditary coagulation factor deficiency. These patients have lifelong bleeding at times including disabling hemarthrosis. Mild to moderate deficiencies of the coagulation factors are more of a diagnostic problem. These disorders are at times unsuspected yet bleeding after surgery or trauma may be quite severe. It is these mild deficiencies which are clinically unsuspected that we hope to detect by our screening coagulation tests.

Factor VIII Deficiency (Hemophilia A)

Factor VIII deficiency and Factor IX deficiency (hemophilia B or Christmas disease) are both inherited as sex-linked recessive traits. In Facor VIII deficiency the actual coagulation protein is not absent. Rather, its is qualitatively abnormal. This explains the classic findings of low Factor VIII coagulation activity in the presence of normal levels of immunologically measured Factor VIII antigen. As will be seen below, a normal level of Factor VIII antigen distinguishes hemophilia A from von Willebrand's disease where both Factor VIII activity and antigen are decreased.

When Factor VIII levels are very low, the activated partial thromboplastin time is markedly prolonged. The severity of the hemophilic disorders correlates directly with coagulation factor activity. In hemophilia A, Factor VIII activity is typically less than 2%. Crippling hemarthroses and other severe spontaneous bleeding develops. As the level of Factor VIII activity increases from 2-25%, episodes of hemarthrosis become less frequent and spontaneous bleeding occurs less often. The PTT which was markedly prolonged when Factor VIII activity was less than 5% approaches the normal range. It is specifically this group of

5 patients with mild hemophilia and Factor VIII levels between 5-40% who may have a normal PTT yet may have serious bleeding after trauma or with surgery. For this reason, a Factor VIII level is obtained when there is a significant bleeding history and the PTT is borderline or normal. The PT and bleeding time are both normal in this disorder.

The goal of therapy for these patients is to restore Factor VIII activity to a hemostatically safe range. Cryoprecipitate has high levels of Factor VIII activity and is the blood product of choice for this disorder. A reasonable therapeutic regimen for patients with bleeding or who are undergoing major surgery consists of a loading dose of 3.5 bags of cryoprecipitate per 10 kg of weight. Maintenance therapy is started 8 hours later with cryoprecipitate 1.75 bags per 10 kg every 8 hours for 1-2 days, followed by cryoprecipitate given every 12 hours. The duration of therapy should be 10-14 days following major surgery or trauma. The exact dose of cryoprecipitate is determined by measuring blood levels of Factor VIII activity and enough cryoprecipitate should be given to prevent Factor VIII activity from falling below 50%. These patients cannot be monitored by the PTT alone since as stated above, this test may be normal with low levels of Factor VIII activity.

Factor IX Deficiency (Hemophilia B or Christmas Disease)

This disorder is seven times less common than Factor VIII deficiency. As with Factor VIII deficiency, the severity of the disease directly correlates with the level of Factor IX activity. The PTT is prolonged while the PT and bleeding time are both normal. The treatment strategy for this disease is similar to that used in the treatment of Factor VIII deficiency except that one generally uses plasma or Factor IX concentrates. The serum half-life of Factor IX is longer than that of Factor VIII and one can usually administer this product at less frequent intervals. Care must be taken in the administration of Factor IX concentrates since they may be associated with potentially dangerous side effects.

Von Willebrand's Syndrome

This illness is now the most commonly recognized congenital factor deficiency. First described in 1926 it is an autosomal-dominant trait with variable expressivity. One generally sees a triad of a mild bleeding history associated with a prolongation of the bleeding time and moderate Factor VIII deficiency. Unlike classic hemophilia where the Factor VIII activity is low but Factor VIII antigen is normal, both coagulation activity and Factor VIII are proportionally reduced in this illness. In addition, there are two biologically related activities, one being coagulant activity (VIIIAHF) and the second correlating with a platelet defect (VIIIvWF) which are reduced in von Willebrand's disease. Platelets do not function normally in this disorder, thus accounting for the prolonged bleeding time. The platelet defect can be corrected with the transfusion of normal platelet-poor plasma.

The clinical history is an important clue in detecting patients with von Willebrand's syndrome. Symptoms usually begin in childhood when one frequently sees mucosal bleeding such as epistaxis. These patients usually are noted to have easy bruisability and have excessive bleeding with surgery. Petechiae are rare despite the fact that there is a platelet defect. The laboratory evaluation of these patients usually reveals a slightly prolonged PTT and a prolonged bleeding time. These patients also have abnormal platelet aggregation studies specifically when platelets are tested in the presence of ristocetin. Patients with classic

6 hemophilia have a normal bleeding time. Measurements of Factor VIII activity are low, though typically not as low as is seen with hemophilia A.

It is very important to realize that there are several variations to this syndrome and at times a screening PTT may be normal. It is for this reason that patients who have a suggestive bleeding history or a strong family history should have additional studies to investigate the possibility of von Willebrand's disease. Additional tests should include specific measurements of plasma Factor VIII activity and Factor VIII antigen, and platelet aggregation studies. At times it may be impossible to differentiate in the laboratory mild variations of von Willebrand's syndrome from normal patients. In this group, if there is a strong bleeding history and surgery is anticipated, one should consider treatment with cryoprecipitate.

An interesting phenomenon has been observed in this disorder whereby normal plasma or even plasma from true haemophilacs will induce new Factor VIII synthesis. It is for this reason that replacement therapy should be started 24 hours before a planned surgical procedure. Another important therapeutic principle to be remembered is that both Factor VIII coagulant activity and the Factor VIII-related plateled defect must be corrected in these patients in order to establish normal hemostasis. Cryoprecipitate contains both of these activities and is the treatment of choice for this disorder. Commercially available Factor VIII concentrations contain only Factor VIII coagulant activity and if these product must be used, additional plasma must be given to correct the Factor VIII-dependent platelet defect.

Factor XI Deficiency

This disorder is typically mild and is seen predominantly but not exclusively in those of Jewish ancestry. Many of these patients present with persistent bleeding after a dental extraction or a tonsillectomy. Since this factor is involved in the intrinsic coagulation system, the PTT is prolonged while other coagulation tests and the bleeding time are normal. Treatment of this disorder is with fresh-frozen plasma. Replacement therapy usually can be given at less frequent intervals since the plasma half-life of this factor is approximately 60 hours. As with other factor deficiencies, the specific amount of replacement therapy should be determined by measurements of plasma Factor XI activity.

Factor XII Deficiency (Hageman Factor)

Factor XII deficiency is associated with a prolongation of the PTT. It is important to separate this factor deficiency from deficiencies of Factors VIII, IX, and XI since it is not associated with abnormal bleeding and no therapy is required.

Deficiencies of Factors II (Prothrombin), V, VII, and X

Congenital deficiencies of these coagulation factors are quite rare. As a group they are associated with prolongation of the PT. In addition, the PTT is typically abnormal in all but Factor VII deficiency. Treatment is with fresh-frozen plasma. However, Factor IX concentrates also may be used since these products contain significant levels of Factors II, VII, and X activity.

7 Acquired Disorders of Coagulation

As a group the acquired disorders of coagulation are more common than congenital coagulation factor deficiencies. In addition, these are typically associated primarily with a prolongation of the PT.

Disseminated Intravascular Coagulation (DIC)

This is a syndrome characterized by the intravascular consumption of platelets and coagulation factors. It may be an acute process caused by shock, infection, or trauma, or may be a chronic process as is typically the case when associated with a disseminated neoplasm. In this syndrome, fibrin deposition may lead to tissue ischemia while depletion of platelets and coagulation factors may cause excessive bleeding. The peripheral blood smear may be helpful in establishing the diagnosis of DIC and may reveal fragmented red blood cells (schistocytes) in addition to thrombocytopenia. In acute DIC the diagnosis may be readily established by noting a low platelet count and serum fibrinogen in association with a prolonged PT and PTT. In addition, fibrin degradation products will generally be increased either secondary to the disseminated intravascular coagulation or the accompanying fibrinolysis which is frequently present. The diagnosis of chronic DIC may be more difficult to establish with certainty, and at times the only laboratory abnormalities may be a reduction in the platelet count and an increase in the amount of circulating fibrin degradation products.

Treatment of DIC is directed at the underlying cause. If bleeding is severe, blood replacement must be given to prevent shock. Cryoprecipitate should be given to replace Factor VIII and fibrinogen which are consumed by the intravascular coagulation and fresh-frozen plasma is given to replace coagulation factors. The use of heparin has been recommended in certain circumstances as a means of inhibiting intravascular coagulation. However, it is actually used infrequently, specifically in certain life-threatening circumstances.

Acquired Inhibitors of Coagulant Factors

Rarely, patients will develop inhibitors to specific coagulation factors. These disorders are detected by the usual screening tests (PT and PTT). More specific tests (PT and PTT mixing studies) will usually separate these disorders from congenital factor deficiencies. Acquired Factor VIII inhibitors may be associated with acute bleeding episodes and require the administration of very large quantities of Factor VIII. Systemic lupus erythematosus, specifically, may be associated with an acquired circulating anticoagulant which can cause a prolongation of either the PT or the PTT. Bleeding is unusual with this disorder and treatment is directed at the underlying illness. Several cases of acquired von Willebrand's disease also have been reported.

Liver Disease

There are many different coagulation problems that may develop in association with liver disease. With severe liver disease, there can be a decrease in the synthesis of the vitamin K-dependent coagulant factors (prothrombin, VII, IX, and X). Patients with steatorrhea and obstructive jaundice also have a reduced absorption of vitamin K from the gastrointestinal tract. In addition, Factors V and fibrinogen will be diminished in patients with very severe

8 liver disease. Thrombocytopenia also is seen frequently in patients with liver disease and may at times suggest the presence of hypersplenism. Both DIC and fibrinolysis also may be seen, especially when the liver disease is severe. Treatment is generally directed at replacing of blood loss in the bleeding patient and fresh-frozen plasm may be given to correct coagulation factor deficiencies. If there is a prolongation of the PT, vitamin K should always be given because of the possibility of concurrent vitamin K deficiency. Thrombocytopenia can be corrected by the administration of platelet concentrates.

Vitamin K Deficiency and Oral Anticoagulants

The vitamin K-dependent coagulation factors (prothrombin, VII, IX, and X) are all synthesized in the liver and are diminished when there is vitamin K deficiency. Vitamin K is a fat-soluble vitamin synthesized by intestinal bacteria. Broad-spectra antibiotics with secondary intestinal sterilization can cause reduced synthesis of vitamin K. This problem may be a specific complication of hospital antibiotic administration, and may contribute to bleeding when there is poor dietary intake. Obstructive jaundice with an inability to absorb the fat- soluble vitamins also is associated with vitamin K malabsorption. The coagulation factors affected by vitamin K deficiency are part of the extrinsic and common coagulation pathway, and it is the PT which is characteristically prolonged in this disorder. Warfarin (Coumadin), an oral anticoagulant, impairs hepatic synthesis of the vitamin K-dependent coagulant factors and is similarly associated with a prolongation of the PT.

It can be seen that vitamin K deficiency, liver disease, and DIC may be present simultaneously, yet each can itself cause a prolongation of the PT. Specific coagulation factor assays (Factors V, VII, and VIII) may help distinguish between these three disorders. Vitamin K deficiency will reduce Factors II, VII, IX, and X with Factor VII generally the first to be reduced. Factors V and VIII are unaffected by vitamin K deficiency or by oral anticoagulants. DIC causes a consumption of the coagulation factors. Factors V and VIII typically have a short plasma half-life and are reduced early in this disorder while Factor VII is variably affected. Severe liver disease (without DIC) will reduce Factor V and the vitamin K- dependent coagulant factors. Factor VIII however is unaffected by liver disease since it is not synthesized in liver.

Therapy of vitamin K deficiency is dependent on the severity of the hemostatic defect. One can administer vitamin K1 (Aquamephyton) which will stimulate synthesis of the reduced coagulation factors within 6-12 hours, or one can administer fresh-frozen plasma which will immediately replace the deficient coagulation factors. Fresh-frozen plasma should be given specifically when there is bleeding and more rapid correction of the PT is required. The starting dose of fresh-frozen plasma is 15-20 mL/kg. Additional therapy may be required if bleeding continues and the PT has not completely corrected.

Heparin

Heparin is the most common anticoagulant administered to hospitalized patients and has potent antithrombin activity. Its administration caused prolongation of the PTT and thrombin time. Performing a thrombin time in the presence of toluidine blue can be used to differentiate the heparin effect from other circulating anticoagulants. Heparin has a short serum half-life and the anticoagulant effect of this drug is usually lost within 4 hours after

9 it is discontinued. In patients with severe bleeding while on heparin, protamine sulphate can be administered to neutralize the heparin effect while carefully monitoring the PTT.

Estimation of Blood Volume

In the physiology laboratory it is possible to measure blood volume accurately with radioactive isotopes or with dye. However, in a clinical situation the following formulas will help the surgeon estimate the blood volume quickly.

1. Blood volume of children in mL = 7.5-8.5% of body weight in grams.

2. Blood volume of adult male in mL = 6-7.5% of body weight in grams.

3. Blood volume of adult female in mL = 5.5-7% of body weight in grams.

For example: A 75 kg male has: 7/100 x 75.000 g = 5250 mL.

Twenty to thirty percent loss of total blood volume is significant and may need replacement. No bloor or plasma transfusion is needed for any blood loss under 20% of total blood volume.

10 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 34: Cancer Chemotherapy

Malignant neoplasms are best treated by surgical removal from the body when they are sufficiently localized and well situated to allow the procedure to be done at reasonable risk and with tolerable side effects. When the tumor is relatively inaccessible, i.e. the posterior third of the tongue, or when function can be better preserved by avoiding surgery, i.e. some cases of limited carcinoma of the larynx, then radiation therapy is indicated. However, when the tumor is no longer regionally confined, or when it is known to have a high incidence of metastasis after surgery, then chemotherapy should be considered.

Modern chemotherapy is relatively new. The first patient was treated in 1943 for a lymphosarcoma, with the only chemotherapy drug then available, nitrogen mustard (mechlorethamine) (then a secret wartime drug), at the New Haven Hospital. Since that time, more than 50 individual drugs have been found effective and are in use singly or in combination. For some neoplasms, they prolong survival or provide a cure. For others, they provide palliation and prolongation of life and for some they provide only palliation with uncertain prolongation of life. Unfortunately, with the currently available drugs, some tumors have uncertain palliation (Table 34-1). The field is sufficiently complex that chemotherapy should be given by an oncologist but the otolaryngologist must understand what is being done and why.

Chemotherapy Drugs

In general, anticancer drugs interfere either with the synthesis of protein, DNA, or RNA by the cell, or they inhibit mitosis. Specific effects on the cell cycle have also been described. Drugs are classified into groups based on their characteristics or their origins.

The usual grouping is:

1. Alkylating agents. 2. Nitrosoureas. 3. Antimetabolites. 4. Mitotic inhibitors. 5. Antitumor antibiotics. 6. Miscellaneous. 7. Hormones or antihormones.

Alkylating Agents

These are highly reactive compounds that substitute an alkyl group for the hydrogen atoms of many organic molecules. The drugs cross-link the strands of DNA, preventing DNA replication and the transcription of RNA. The major site of action is the N-7 position of guanine. Most of the commonly used alkylating agents are derivatives of nitrogen mustard, like chlorambucil, cyclophosphamide, and melphalan. Busulfan is an alkyl sulfonate and thiotepa is a trifunctional alkylating agent. Some drugs seem to act like alkylating agents and are therefore grouped with them such dibromodulcitol, dacarbazine, estramustine, and cisplatin

1 (Table 34-2). They are effective in many tumors including lymphomas, lung, testicular and ovarian cancer, and chronic leukemias. Cisplatin has proven efficacy in testicular and ovarian carcinoma and is showing great promise in clinical trials in lung and in head and neck cancer.

Nitrosoureas

These are group of drugs that are lipid soluble and behave like alkylating agents. They can gain access to the central nervous system and other areas that require lipid solubility. They all have a chloroethyl side arm linked to a nitrosourea moiety. In addition to alkylation, they also act by carbamoylation and inhibit both DNA and RNA. They lack cross-resistance with the other alkylating agents. They have been used primarily in treatment of primary brain tumors, lymphomas, myeloma, and gastrointestinal (GI) neoplasms (Table 34-3).

Antimetabolites

These agents interfere with the biologic synthesis of DNA and RNA either by blocking enzyme pathways or by being incorporated themselves into a defective DNA.

Antimetabolites are frequently structural analogues of normal metabolies essential for cell growth and replication. Hence, they are most effective in rapidly growing tumors. They are usually divided into the pyrimidine analogues (5-azacitidine, 5-fluorouracil, hexamethylmelamine), purine analogues (6-mercaptopurine, 6-thioguanine), and the folic acid antagonists (methotrexate, triazinate). Although hydroxyurea does not look like an antimetabolite it appears to behave like one and is grouped with the antimetabolites. The primary role of the antimetabolites is in treatment of leukemias and carcinoma of the ovary, breast, stomach, pancreas, and colon (Table 34-4). Methotrexate has been the single most widely used drug for treatment of head and neck cancers that are unresectable or metastatic. It has been used both in normal dosage and in programs with high-dose and leucovorin- rescue. The only controlled clinical trial so far showed no difference in the two regimens.

Mitotic Inhibitors

These drugs have been derived from plants, either the periwinkle plant (Vinca rosea Linn) or Americal mandrake plant (Podophyllum peltatum). They bind to microtubules and cause metaphase arrest thereby inhibiting effective mitosis. They are active in leukemia, lymphoma, lung, testicle, and breast cancer (Table 34-5).

Antitumor Antibiotics

These agents have been isolated from a great variety of microorganisms in many parts of the world. They act to affect the synthesis or function of nucleic acids and especially DNA. Antimitotic and cell surface effects may occur with these agents. These drugs have a wide spectrum of activity including childhood tumors, sarcomas, leukemias, lymphomas, breast, bladder, ovary, testicle, and head and neck cancers (Table 34-6). Mithramycin also has been used for the treatment of hypercalcemia caused by malignancy.

2 Miscellaneous Agents

This includes those drugs that do not readily fit into one of the other group designations. Mitotane (o,p'-DDD) is used solely in the treatment of adrenal cortical carcinoma. Procarbazine has been used primarily in a four drug combination for treatment of Hodgkin's disease and other lymphomas. L-Asparaginase is unique in that it is an enzyme product that acts by inhibiting protein synthesis by depriving tumor cells of the amino acid asparagine. Since normal cells can synthesize their own asparagine, they are unaffected. Thus this is the first antineoplastic agent that is effective against some cancer cells and is not toxic to most cells. Unfortunately, the enzyme is prepared from bacteria and therefore is a foreign protein which elicits fever, an antibody reaction, and can cause rash or even anaphylaxis. It is used primarily in the treatment of childhood acute lymphocytic leukemia and must be used with extreme caution (Table 34-7).

Hormones and Antihormones

Adrenal corticosteroids have been used for a long time in the treatment of leukemia, breast cancer, and lymphoma. Estrogens, especially diethylstilbestrol and chlorotrianisene (TACE), have been used for prostatic carcinoma and occasionally for late postmenopausal patients with breast cancer. Androgens have been used in the management of breast cancer for many years. Recently, progestational agents like megestrol, hydroxyprogesterone, and medoxyprogesterone have been used in the treatment of endometrial carcinoma and renal cell carcinoma.

The antiestrogen, tamoxifen (Nolvadex), is a nonsteroidal agent that blocks the estrogen effect possibly by binding to cytoplasmic receptors. It has been effective in the majority of patients with breast cancer whose tumor was estrogen-receptor positive. It is given orally and has minimal side effects. Aminoglutethimide (Cytadren) inhibits the enzymatic conversion of precursors to adrenal gluococorticoids and mineralocorticoids, and to estrogens. In effect, it causes a "medical adrenalectomy" that is as efficacious as a surgical adrenalectomy. It has been useful in many cases of breast cancer and prostate cancer.

Chemotherapy for Head and Neck Tumors

Most primary tumors of this area are of the squamous cell type. The traditional drug of choice has been methotrexate. In recent years, promising reports have indicated efficacy for bleomycin and cisplatin. Combinations of these agents were tried and are still being tried, but so far the toxicity has been severe and hence limiting. Combined modality therapy with surgery, radiation, and chemotherapy also is being evaluated. Results are better than before, but still far from satisfactory.

Attempts at intra-arterial infusion of chemotherapy drugs has gone through cycles of popularity and disillusionment at a number of research centers. It seems clear that for better results we will need better drugs and better ideas.

3 Lymphomas

One of the most common tumors seen by otolaryngologists is the lump in the neck that when eventually excised or a biopsy taken is found to be Hodgkin's disease or non-Hodgkin's lymphoma. This is extremely important because most cases of early Hodgkin's disease can be cured and most non-Hodgkin's lymphomas can be effectively palliated.

Hodgkin's Disease

Hodgkin's disease should be staged according to the Ann Arbor modification of the Rye classification. Patients are divided into four stages (Table 34-8) and subclassified A (absence) or B (presence) of systemic symptoms of unexplained fever, weight loss, and night sweats.

There is general agreement that patients in stage IA, IB, and IIA should be treated with radiation therapy and have a better than 90% remission rate that is probably a cure. Patients with IIIB, IVA, and IVB disease should be treated with combination chemotherapy and can expect a 75-80% remission rate, but with 40-50% relapsing so that the overall cure rate is only 50%. There is controversy among experts on the treatment of IIB and IIIA disease with advocates of radiation therapy alone, chemotherapy alone, and combined radiation plus chemotherapy. Clinical trials are in progress to answer the question.

The "standard" chemotherapy for Hodgkin's disease is known by the acronym MOPP and consists of monthly courses of mechloretamine, vincristine (Oncovin), procarbazine, and prednisone. Patients who fail or relapse on this regiment, are usually treated with ABVD, a noncrossreactive combination consisting of doxorubicin (Adriamycin), bleomycin, vinblastine, and dacarbazine. Frequently, these patients can be salvaged after a radiation therapy failure or the failure of the initial chemotherapy regimen.

Non-Hodgkin's Lymphoma

Although the same staging system is used (Table 34-8), it is less satisfactory than in Hodgkin's disease. The disease tends to be multifocal or spreads rapidly. Hence, only the rare stage IA patient is treated with radiation. All others are treated with chemotherapy. The pathologic classification has been in a state of flux with nomenclature changes reflecting the rapid increase in knowledge. In general, patients with nodular disease have a more indolent course and a longer survival than those with diffuse disease. Patients with predominantly lymphocytic (small round cell) disease do better than those with so-called histiocytic disease which is really large cell lymphocytic (usually not round) type disease. Although those with nodular lymphocytic disease have a long survival, they are seldom cured. Most patients with diffuse histiocytic disease have a poor prognosis, but a subset, about 20-30%, treated with aggressive combination chemotherapy, will have a long survival that may be a cure.

Twenty years ago, all patients with Hodgkin's disease were doomed to die. Now better than 90% of early cases and 50% of late cases can be cured. With the development of more knowledge and better drugs and drug combinations, better combined modality therapy of surgery, radiation, and chemotherapy, it is only a matter of time until we will be able to cure most malignancies. It is our hope that that day will arrive sooner rather than later.

4 Table 34-8. Ann Arbor Staging System of Hodgkin's Disease

Stage I

Involvement of a single lymph node region (I) or of a single extralymphatic organ or site (IE).

Stage II

Involvement of two or more lymph node regions on the same side of the diaphragm (II) or localized involvement of extralymphatic organ or site and of one or more lymph node regions on the same side of the diaphragm (IIE).

Stage III

Involvement of lymph node regions on both sides of the diaphragm (III), which also may be accompanied by localized involvement of extralymphatic organ or site (IIIE), by involvement of the spleen (IIIS), or both (IIISE).

Stage IV

Diffuse or disseminated involvement of one or more extralymphatic organs or tissues with or without associated lymph node enlargement.

Subclassification: A for absence or B for presence of (a) unexplained weight loss of more than 10% of body weight; (b) unexplained fever above 38°C; and (c) night sweats.

Pathologic staging: Designate + for positive; - for negative by biopsy; N for lymph node; H for liver; S for spleen; L for lung; M for marrow; P for pleura; O for bone (osseous); D for skin (dermis).

5 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 35: Antimicrobials

Penicillins

All penicillins have a basic structure composed of a beta-lactam ring and a thiozolidine ring. The third component, the side chain, varies and determines the antibacterial spectrum of the drug. Penicillins are bactericidal drugs that interfere with cell wall synthesis in growing bacteria. The penicillins can be classified on the basis of similar spectra. Penicillins are excreted into the urine. They reach adequate levels in the CSF, brain, and eye only in the presence of inflammation. The most frequent untoward effect is hypersensitivity that may be as serious as anaphylaxis. Central nervous toxicity may result from massive doses, especially in the presence of renal failure.

Natural Penicillins

1. Penicillin G (Pfizerpen, Pentids, SK-Penicillin).

a. Procaine (Wycillin, Crystacillin, Duracillin).

b. Benzathine (Bicillin).

2. Penicillin V (Pen-Vee K, Pfizerpen, Uticillin, V-Cillin K, Veetids, Betapen-VK).

Penicillin G remains the drug of choice for all infections caused by sensitive organisms, including Streptococcus (except enterococcus), pneumococcus, Neisseria meningitidis, N. gonorrhoeae, anaerobes (except most Bacteroides fragilis), syphilis, Leptospira, Listeria monocytogenes, Clostridia specia, anthrax bacillus and Actinomyces. Crystalline penicillin G is given intravenously. Delayed absorption forms (procaine and benzathine) are given intramuscularly. Penicillin V has a spectrum similar to penicillin G, but has better absorption after oral administration. It usually is substituted for penicillin G when oral therapy is indicated.

Semisynthetic (Penicillinase-Resistant) Penicillins

1. Methicillin (Staphcillin, Celbenin).

2. Nafcillin (Unipen, Nafcil).

3. Oxacillin (Prostaphlin, Bactocil).

4. Dicloxacillin (Dynapen, Pathocil, Veracillin).

These drugs are resistant to staphylococcal penicillinase, and their only indication is in the treatment of infections caused by penicillin G-resistant staphylococci. Side effects include those listed for penicillins as well as interstitial nephritis (methicillin), neutropenia

1 (high-dose oxacillin), and hepatitis (oxacillin). For serious infections these drugs should be given intravenously in doses of 9-12 g daily.

Of this group, dicloxacillin reaches the highest levels after oral administration. Staphylococci that are "tolerant" and resistant to the semisynthetic penicillins are being reported with increased frequency.

Aminopenicillins

1. Ampicillin: (Amcill, Omnipen, Polycillin, Penbritin, Pensyn, Principen, Totacillin).

2. Amoxicillin: (Amoxil, Larotid, Polymox, Robamox, Trimox, Wymox).

These L-aminobenzyl penicillin derivatives were the first broad-spectrum penicillins. They have activity against many gram-negative organisms, but are not resistant to penicillinase. Ampicillin has more activity than penicillin G against enterococci and gram- negative rods including Haemophilus influenzae, Shigella, Salmonella, many Escherichia coli, and Proteus mirabilis. It is slightly less active than penicillin G against grou A streptococci and pneumococci. Amoxicillin has a spectrum almost identical to ampicillin, but reaches higher peak blood levels after an oral dose. The most frequent side effects are hypersensitivity rash and gastrointestinal upset with oral administration.

Antipseudomonas Penicillins

1. Carbenicillin (Geopen, Pyopen).

a. Indanyl carbenicillin (Geocillin).

2. Ticarcillin (Ticar).

3. Piperacillin (Avocin).

4. Mezlocillin (Baypen, Mezlin).

These drugs are active against organisms sensitive to ampicillin and against indole- positive Proteus, some Enterobacter species, most anaerobic gram-negative bacteria, and, most important, most strains of Pseudomonas aeruginosa.

Carbenicillin and ticarcillin must be used intravenously in daily doses of 24-30 g and 18 g, respectively. Both contain large amounts of sodium in the sodes listed and can cause fluid overload. Both interfer with platelet function, but not platelet numbers, and may cause neutropenia with prolonged use. These drugs should be used with aminoglycosides in the treatment of severe pseudomonas infections. Indanyl carbenicillin is indicated only for the oral treatment of pseudomonas urinary tract infections; it does not reach adequate tissue levels in any other system.

2 Piperacillin and mezlocillin are newer agents with extended spectra. Piperacillin has greater activity than any other penicillin against Pseudomonas aeruginosa. Mezlocillin is more active than carbenicillin against enterococci, Klebsiella species, and B. fragilis.

Cephalosporins

These semisynthetic antibiotics are bactericidal and act like penicillins to inhibit cell wall synthesis. There are a wide variety of these agents with a range of absorption, tissue penetration, and spectrum of antibacterial activity. The first-generation cephalosporins have primarily gram-positive and limited gram-negative activity. The second-generation have more extensive gram-negative as well as anaerobic bacterial coverage. Thrid-generation cephalosporins are active against some strains of Pseudomonas.

Cephalosporins are acetylated to some extent in the body. Active and inactive metabolites are excreted in the urine.

Toxicity and Side Effects

1. Hypersensitivity reactions are the most common complication of cephalosporin therapy. The incidence of cross-reactivity with penicillin hypersensitivity is less than 10%, and cephalosporins can be given with caution to penicillin-hypersensitive patients.

2. Hematologic: A positive direct Coombs' test occurs in some patients receiving cephalothin.

3. Elevated SGOT occurs rarely in association with cephalosporin therapy and usually is not of clinical significance.

4. Neutropenia is occasionally noted, particularly with the newer cephalosporins.

Cephalothin (Keflin)

This drug is effective for gram-positive infections including penicillinase-producting staphylococci. It is also active against some gram-negative organisms such as Klebsiella, Proteus mirabilis, and E. coli.

Cefazolin (Kefzol, Ansef)

This drug has a longer half-life and less pain with intramuscular injection than cephalothin. Its spectrum of activity is identical.

Cephalexin (Keflex)

Cephalexin is absorbed orally, but is less active against many staphylococci and some anaerobes. It should not be used to treat serious deep tissue infections. Note: This drug is not as effective as penicillin for most oral-pharyngeal bacteria.

3 Cephaloglycin (Kafocin)

This is another oral cephalosporin with less absorption than cephalexin, and little clinical usefulness.

Cephapirin (Cefadyl)

Cephapirin is pharmacologically equivalent to cephalothin.

Cephradine (Velosef, Anspor)

Cephradine is similar to cephalexin, but with both oral and parenteral administration.

Cefaclor (Ceclor)

This is an oral cephalosporin with some activity against Haemophilus influenzae. It should not be used for serious deep tissue infections.

Cefamandole (Mandol)

Cefamandole is a second-generation cephalosporin with expanded gram-negative spectrum including some Enterobacter and Serratia, as well as some activity against Bacteroides fragilis.

Cefoxitin (Mefoxin)

Cefoxitin is actually a cephamycin rather than a cephalosporin. It has an extended gram-negative spectrum and is more active than cefamandole against B. fragilis. However, it is less active against many staphylococci and streptococci.

Cefotaxime (Claforan)

This is a third-generation cephalosporin with a broad range of activity for gram- negative organisms including some strains of Pseudomonas and B. fragilis. It is less active than cephalothin for Staphylococcus.

Moxalactam (Moxam)

A third-generation cephalosporin with extended range of activity including some strains of Pseudomonas, it is also highly active for N. gonorrhoeae. It may be drug of choice for gram-negative meningitis.

Aminoglycosides

These are bactericidal agents that interfere with protein synthesis of the 30S subunit of bacterial ribosomes, causing misreading of the genetic code.

4 These drugs are not absorbed from the gastrointestinal tract. They are excreted primarily unchanged as active drug in the urine. Dosage must be decreased with renal failure.

Concentrations of drugs of about one-third of serum levels are achieved in tissue, sputum, and saliva. CSF penetrance is poor.

Aminoglycosides are active against many gram-negative bacteria, staphylococci, and mycobacteria. They are not active against anaerobes or streptococci.

Ototoxicity and Side Effects

1. Ototoxicity: Irreversible cochlear and vestibular damage are common. Deafness occurs more commonly with kanamycin and neomycin, while vestibular dysfunction is more common with gentamicin and tobramycin. This toxicity is potentiated by preexisting renal disease, high serum drug levels, and sometimes with prolonged drug usage.

2. Nephrotoxicity: Damage to renal proximal tubular cells may cause reversible azotemia. This toxicity is associated with high serum peak-and-through drug levels, preexisting renal disease and, elderly patients.

3. Neuromuscular blockade: Neomycin, streptomycin, and kanamycin may cause a curarelike neuromuscular blockade which is potentiated by anesthesia and especially common with the peritoneal route of antibiotic administration.

4. Hypersensitivity: Rashes and drug fever are rarely seen with aminoglycosides.

Streptomycin

Streptomycin is used primarily to treat tuberculosis, and combined with penicillin for enterococcal endocarditis. Its most serious toxicity is vertigo from vestibular damage. This is related to both total dose and peak serum dose.

Kanamycin

Kanamycin is used almost exclusively as an oral bowel-sterilizing agent before bowel surgery.

Gentamicin

Gentamicin is the agent of choice for many gram-negative bacterial infections, and is combined with penicillin or semi-synthetic penicillin to treat staphylococcal and enterococcal endocarditis. It may cause eight nerve damage when administered as otic drops when the tympanic membrane is ruptured.

Tobramycin

Tobramycin has a similar spectrum of activity to gentamicin. It is the preferred agent for pseudomonas infection, and has a synergy with carbenicillin for Pseudomonas. The

5 incidence of ototoxicity is the same as for gentamicin. Some investigatores claim less nephrotoxicity, but others disagree.

Amikacin

Amikacin has a similar spectrum of activity to gentamicin and tobramycin. It is sometimes active against hospital-acquired resistant gram-negative bacteria. It has a higher incidence of cochlear damage and the same degree of nephrotoxicity as gentamicin. This drug should be reserbved for bacteria resistant to gentamicin and tobramicin.

Neomycin

Neomycin is used for topical administration only. It usually is combined with polymyxin B and bacitracin in creams and sprays such as Neosporin ointment. Its activity is against staphylococci and most gram-negative bacteria except Pseudomonas. As a topical agent it may be systematically absorbed to cause progressive nerve deafness. It also may cause deafness when instilled in the otic canal with a perforated tympanic membrane.

Sisomicin and Netilmicin

These drugs were developed for serious gram-negative infections. Amikacin, however, usually is more active against gentamicin-resistant strains. These agents are therefore rarely indicated.

Bacitracin

Bacitracin is for topical use only. It is active against most gram-positive organisms including staphylococci and streptococci. Gram-negative bacteria are resistant. It is a topical agent not absorbed systemically like neomycin.

Chloramphenicol

Chloramphenicol is a bacteriostatic agent that inhibits protein synthesis by reversibly binding to the 50S bacterial ribosome, preventing peptide bond formation. Chloramphenicol has a broad spectrum of activity. It is active against most gram-positive and gram-negative aerobic bacteria with the exceptions of Pseudomonas aeruginosa and many Enterobacter, Serratia, and indole-positive Proteus species. It has excellent activity against anaerobic bacteria, rickettsiae, and mycoplasmas. The excellent penetration of chloramphenicol into the CSF makes it the initial drug of choice in most cases of meningitis. It also achieves therapeutic levels in other body tissues and fluids, including the aqueous humor. Chloramphenicol is metabolized in the liver, and dosage adjustment is not required in renal failure.

6 Toxicity and Side Effects

Bone Marrow

The toxicity of chloramphenicol is manifest primarily in the bone marrow and is of two types. The first, aplastic anemia, is a rare idiosyncratic response and not dose related. This type of toxicity, generally irreversible and fatal, rarely occurs with parenteral chloramphenicol.

The second type of toxicity is the more common dose-related bone marrow suppression. This produces anemia, leukopenia, and/or thrombocytopenia. These effects are reversible when the drug is dicontinued.

Gray Baby Syndrome

Premature and newborn infants who receive large doses of chloramphenicol can develop circulatory collapse with a high mortality. The drug should not be given in late pregnancy or during breast-feeding.

Hypersensitivity

Rashes and drug fever are rarely noted.

Lincomycin (Lincocin) and Clindamycin (Cleocin)

These antibiotics act to inhibit bacterial protein synthesis at the 50S subunit. They are well absorbed orally, tolerated parenterally, and metabolized by the liver. High concentrations are achieved in most body tissues and the saliva. Cerebral spinal fluid concentrations are low. Doses should be reduced with liver failure. They are active against most gram-positive organisms including penicillinase producing staphylococci. Clindamycin is a first-line agent for infections with B. fragilis.

Toxicity and Side Effects

1. Pseudomembranous colitis: This life-threatening complication is due to overgrowth of Clostridium difficile in the bowel flora. It is more common when these antibiotics are administered orally. This complication is not, however, unique to these drugs and occurs following administration of most other classes of antibiotics.

2. Nausea, vomiting, and diarrhea: Relatively common side effects which often precede pseudomembranous colitis.

3. Hypersensitivity: Drug fever and skin rash occur commonly with clindamycin.

4. Elevated SGOT is occasionally noted, but of little clinical significance.

7 Erythromycin

Erythromycin is the most important of the macrolide antibiotics. It is generally considered to be bacteriostatic, but can be bactericidal at higher concentrations. Erythromycin binds reversibly to the 50S ribosomal subunit in bacterial cells and interferes with chain elongation in protein synthesis. It has a broad spectrum of activity against bacteria, treponemas, and mycoplasmas. It is the agent of choice in Mycoplasma pneumoniae infections, Legionnaires' disease, diphtheria, and pertussis. It also is important in treating pneumococcal pneumonia, syphilis, gonorrhea, and group A streptococcal infections in penicillin-allergic patients.

Erythromycin is excreted in bile and, to a lesser extent, in urine. Most appears to be inactivated by metabolic degradation in the liver. Erythromycin achieves therapeutic levels in body tissues and fluid other than the brain and CSF.

Toxicity and Side Effects

Erythromycin causes few untoward reactions. Side effects include dose-related gastrointestinal distress, thrombophlebitis with intravenous use, and occasional allergic reactions. Hepatotoxicity may result from use of the estolate preparation. Large intravenous doses (more than 3 g/day) may cause transient hearing loss.

Tetracyclines

This group of broad-spectrum bacteriostatic agents are generally administered orally. Tetracyclines bind reversibly to 30S ribosomes in bacterial cells and block the transfer RNA. They are active against many gram-positive and gram-negative bacteria excluding most Enterococcus and Proteus, Pseudomonas, and Klebsiella species. Rickettsiae, chlamydiae, and mycoplasmas also are susceptible to tetracyclines.

The tetracyclines are divided into three pharmacologically distinct groups: (1) short- acting: tetracycline, chlortetracycline, oxytetracycline; (2) intermediate: demeclocycline; (3) long-acting: doxycycline and minocycline.

All the tetracyclines are excreted primarily by the kidneys and are, with the exception of doxycycline, contraindicated in renal failure. Absorption of these compounds from the gastrointestinal tract is hindered by milk and calcium, magnesium, and aluminium-containing drugs. Tetracycline achieves adequate levels in most tissues and body fluids except the CSF. However, only minocycline reaches high enough levels in the saliva to cure meningococcal carriers.

Toxicity and Side Effects

Important toxicities and side effects include hypersensitivity reactions, photosensivity reactions, gastrointestinal upset, hepatotoxicity, azotemia, vertigo (minocycline), and superinfection. Because they often cause discoloration of forming tooth enamel, tetracyclines are rarely indicated in pregnant women and children under age 8.

8 Vancomycin

Vancomycin is a bactericidal antibiotic that inhibits bacterial wall synthesis via a different mechanism than penicillins and cephalosporins. The drug is not absorbed orally. It is excreted unchanged by the kidneys. Dosage must be decreased with renal failure. Therapeutic levels are achieved in most body tissues except the CSF.

Vancomycin is active against most gram-positive organisms including enterococci, and is drug of choice for most methicillin-resistant staphylococcal infections. It also is used orally to suppress bowel flora and to treat antibiotic-induced pseudomembranous colitis.

Toxicity and Side Effects

1. Ototoxicity: Reversible and irreversible deafness may occur with high serum levels, particularly in elderly patients.

2. Nephrotoxicity: Vancomycin may cause azotemia, particularly when combined with other nephrotoxic drugs such as aminoglycosides.

3. Hypersensitivity: Skin rashes, urticaria, drug fever, and eosinophilia are common.

Sulfonamides and Trimethoprim

Sulfonamides are synthetic antimicrobials which are generally bacteriostatic. They interfere with folic acid production in bacteria. They inhibit a broad range of gram-positive and gram-negative bacteria as well as Actinomyces, chlamydiae, Toxoplasma, and some Plasmodidae.

Trimethoprim also inhibits bacterial folic acid production. It blocks the enzymatic reaction that is directly after the step blocked by sulfonamides. Trimethoprim most commonly is used in fixed combination with sulfamethoxazole for the treatment of urinary tract infections, chronic bronchitis, bacterial gastroenteritis, and infections caused by Pneumocystis carinii.

Both trimethoprim and sulfonamides are excreted in the urine as free drugs and as metabolites.

Toxicity and Side Effects

Gastrointestinal upset, rash, headache, fever, aplastic anemia, leukopenia, thrombocytopenia, and hemolytic anemia in glucose 6-phosphate dehydrogenase (G-6-PD)- deficient individuals are the most common untoward effects.

Metronidazole

A metronidazole compound that has long been used orally in the treatment of infections caused by anaerobic protozoa such as amebiasis and giardiasis, has recently been released in intravenous form for the treatment of selected anaerobic bacterial infections. It has

9 no activity against aerobic or facultative anaerobic bacteria and should not be used alone for the treatment of mixed aerobic/anaerobic infections such as those caused by mouth flora. The mechanism of action of metronidazole has not been fully described. The primary route of excretion is renal with a major proportion excreted as inactive metabolites. Therapeutic levels of the drug are reached in the CSF and brain abscess cavities.

Toxicity and Side Effects

These include gastrointestinal intolerance, neutropenia, and peripheral neuropathy. Metronidazole has been found to be carcinogenic in high doses in laboratory animals. This effect has not been demonstrated in humans.

A summary of antimicrobial susceptibility profiles for gram-negative rods is given in Table 35-1; for gram-positive cocci in Table 35-2; gram-positive rods Table 35-3; and gram- negative cocci Table 35-4 at the end of this chapter.

Antituberculous Agents

Isoniazid

Isoniazid (INH) is a synthetic agent which, by inhibiting the cell wall synthesis of Mycobacterium tuberculosis, is bactericidal against actively growing organisms.

The major toxicity associated with isoniazid is hepatitis. INH hepatitis can be fatal if not recognized early. The incidence increases with age and with preexisting liver disease.

Ethambutol

This is a tuberculostatic agent that probably acts as an antimetabolite by inhibiting mycobacterial RNA synthesis. Because resistant strains rapidly develop during therapy, ethambutol must be used in combination therapy.

The main complication of ethambutol therapy is retrobulbar neuritis. If the drug is discontinued soon after the onset of symptoms, the condition usually reverses.

Rifampin

Although primarily used in the treatment of tuberculosis, rifampin has a broad spectrum of activity against gram-positive and gram-negative bacteria. Because it reaches high levels in the saliva, it is used for prophylaxis of meningococcal-exposed patients and carriers of the organism. Rifampin is bactericidal against M. tuberculosis by inhibiting RNA synthesis.

The major untoward reaction is hepatotoxicity that may be potentiated by INH. It causes the urine and body secretions to have an orange color.

10 Antifungal Agents

Amphotericin

Amphotericin is the drug of choice for most systemic fungal infections including candidiasis, histoplasmosis, cryptococcosis, coccidiomycosis, sporotrichosis, aspergillosis, and blastomycosis. It is a polyene which binds to ergosterol in the plasma membrane of the fungus, thus altering the permeability of the cell. After an initial 1 mg test dose, amphotericin is given intravenously in gradually increasing daily doses up to 1 mg/kg/day (maximum 50 mg). For severe systemic diseases a total dosage of 1-2 g is administered.

Infusions of amphotericin may be accompanied by chills, fever, nausea, vomiting, hypotension, headache, and anorexia. Many of these symptoms can be prevented by premedication with antipyretics and small dosages of intravenous hydrocortisone. The most important toxicity is renal. Azotemia occurs to some degree in almost all patients treated, and the dosage may have to be adjusted to serum creatinine. Amphotericin also may suppress bone marrow erythropoiesis and cause anemia.

Flucytosine (5-Fluorocytosine)

This is a fluorinated cytosine which interferes with DNA synthesis after being incorporated by the fungal cell into pyrimidine metabolism. It is a well-absorbed oral agent usually used with amphotericin B in the treatment of infections caused by Candida and Cryptococcus. Drug resistance develops rapidly when 5-FC is used alone. Toxicity is low, but bone marrow suppression does occur and is more common when 5-FC is used with amphotericin B or in azotemic patients.

Ketoconazole

Ketoconazole is a new oral imidazole currently being used for long-term therapy of patients with chronic fungal infections. It appears to be effective in the treatment of chronic mucocutaneous candidiasis and usually has little toxicity even after months of use.

Like the other imidazoles, ketoconazole damages the plasma membranes of fungi.

Culture Media

Blood Agar (BA). Nutrient agar plus 3-5% sheep or other blood. It is a general medium that supports the growth of most pathogens. Bacteria produce different, and often characteristic, hemolytic patterns on blood agar.

Chocolate agar (CA). Blood agar that has been heated at 70-80°C to disrupt the red blood cells. This releases Factor X (hemin), a nutrient required by some fastidious organisms such as Haemophilus influenzae and Neisseria gonorrhoeae. Factor V (NAD) is usually added.

Trypicase soy broth (TSB). A nutrient broth that supports the growth of most aerobes and facultative anaerobes.

11 Thioglycollate broth (thio). A nutrient broth that has an oxidation-reduction potential that supports the growth of obligate anaerobes.

Eosin-methylene blue agar (EMB), desoxycholate agar (DCA), MacConkey agar (MCA). Selective media for the growth of the Enterobacteriaceae, Pseudomonas, and certain other gram-negative rods. Lactose is the only carbohydrate, and colonies that utilize it ('lactose fermenters') appear red.

Thayer-Martin agar (TM). Chocolate agar that contains antibiotics to inhibit normal throat and genital flora. It is a selective medium for gonococcus and meningococcus.

Xylose-lysine-desoxycholate agar (XLD) and Salmonella-Shigella agar (SS). Inhibirs Enterobacteriaceae and promotes growth of Salmonella and Shigella species. Salmonella colonies are often black, indicating H2S production.

Müller-Hinton agar. A beef infusion agar used for antibiotic disc sensitivity testing.

Sabouraud dextrose agar (SAB). Supports the growth of and selects for fungi. Low pH inhibits bacterial growth.

Transport medium. Charcoal agar. Keeps the specimen (swab) moist, but does not promote bacterial growth.

Viral culture medium. Tissue culture fluid which should be held at 4°C after inoculation.

Table 35-1. Gram-Negative Rods

Acinetobacter Gentamicin B Used to be called Mima-Herellea A.

Bacteroides B. fragilis Clindamycin Chloramphenicol Metronidazole Carbenicillin (high-dose) (Cefoxitin) (Cefamandole) Some authorities question efficacy of new cephalosporins.

Other species Penicillin Tetracycline Cephalosporin Oral-pharyngeal flora usually penicillin-sensitive.

12 Brucella Tetracycline Streptomycin Sulfa

Campylobacter Erythromycin Tetracycline Gentamicin Common cause of infectious diarrhea. Used to be called Vibrio fetus.

E. coli Ampicillin Cephalosporin Gentamicin TMP-SMX Most community acquired are ampicillin sensitive.

Enterobacter Gentamicin B (Cefamandole) A

Haemophilus influenzae Ampicillin Chloramphenicol TMP-SMX Cefamandole Increasing ampicillin resistance requires lab sensitivity.

Klebsiella Cephalosporin Gentamicin

Legionella pneumophila Erythromycin Legionnaires' disease.

Morganella morganii Gentamicin B Used to be called Proteus morganii A.

Pasteurella Streptomycin Tetracycline Sulfa

13 Proteus mirabilis Ampicillin Cephalosporin Gentamicin TMP-SMX

Proteus vulgaris and P. rettgeri Gentamicin (Cefoxitin) Usually hospital acquired, often antibiotic resistant A.

Providencia Gentamicin (Cefoxitin) A

Pseudomonas Tobramycin Carbenicillin (high doses) Amikacin Tobramycin more active than gentamicin. Most authorities doubt efficacy of new cephalosporins A.

Salmonella Ampicillin Chloramphenicol TMP-SMX TMP-SMX recommended for carrier state.

Serratia Gentamicin (Cefoxitin) A

Shigella TMP-SMX Ampicillin Chloramphenicol Many strains now chloramphenicol resistant.

A Usually hospital acquired (nosocomial) and resistant to many antibiotics. B Sensitivity pattern varies widely. Amikacin, TMP-SMX, second- or third-generation cephalosporins may be used depending on sensitivity.

& Gentamicin and tobramycin usually have identical sensitivities. Gentamicin is selected as aminoglycoside of choice of lower cost.

14 && New cephalosporins in parenthesis are active in vitro. Clear clinical advantage over aminoglycosides, TMP-SMX, and narrow-spectrum cephalosporins is doubtful.

Table 35-2. Gram-Positive Cocci

Pneumococcus Penicillin Cephalosporin Erythromycin Increased penicillin resistance requires lab sensitivity.

Streptococcus viridans Penicillin Cephalosporin Some authorities combine penicillin and aminoglycoside for endocarditis.

Microaerophilic streptococci and anaerobic streptococci (Peptostreptococcus) Penicillin Cephalosporin Erythromycin Normal mouth and GI flora.

Beta-hemolytic streptococcus groups A, B, C, G Penicillin Cephalosporin Erythromycin

Group D streptococcus (Strep. bovis) Penicillin Cephalosporin Erythromycin Endocarditis associated with colonic carcinoma.

Strep. fecalis (Enterococcus) Ampicillin Vancomycin Penicillin and aminoglycoside for treatment of endocarditis.

Staphylococcus aureus Non-penicillinase producing Penicillin Cephalosporin Vancomycin Vancomycin treatment of choice for methicillin-resistant Staph. aureus.

Staphylococcus aureus Penicillinase producing Methicillin

15 Oxacillin Vancomycin Cephalosporin Cephalexin, cefoxitin not recommended for staphylococcus infection.

Staphylococcus epidermidis (coagulase-negative) Cephalosporin (Penicillin) Vancomycin Most hospital-acquired Staph. epidermidis are penicillin resistant.

Actinomycosis Penicillin Tetracycline Sulfa Often requires prolonged treatment.

Bacillus sp. B. subtilis Penicillin Cephalosporin Usually lab contaminant.

B. anthracis Penicillin Cephalosporin

Clostridium C. perfringens Penicillin Cephalosporin

C. tetani Penicillin Cephalosporin

C. difficile Vancomycin Cause of antibiotic-induced pseudomembranous colitis.

Corynebacterium Penicillin Erythromycin Cephalosporin

Listeria

16 Penicillin Ampicillin Cephalosporin Associated with neoplasms and immunosuppressive therapy.

Table 35-4. Gram-Negative Cocci

Gonococcus Penicillin Ampicillin Tetracycline Spectinomycin Increasing penicillin resistance requires lab sensitivity.

Meningococcus Penicillin Chloramphenicol Rifampin drug of choice for prophylaxis.

Spirochetae T. pallidum (syphilis) Penicillin Tetracycline Erythromycin Neurosyphilis requires parenteral treatment for 10-14 days.

Mycoplasma Tetracycline Erythromycin

Chlamydiae Tetracycline Sulfa Chloramphenicol

Riskettsiae Tetracycline Chloramphenicol.

17 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 36: Medications

Antihistamine

An antihistamine acts as a competitive antagonist by occupying the "receptor site" on the effector cells. It does not prevent the release of histamine nor does it destroy the histamine. The basic formula for an antihistamine is:

(R1-X-R2) - CH2 - CH2 - NR2

There are many derivatives sharing the same pharmacologic action and side effects. In general, an antihistamine blocks the histamine effect on smooth muscles of the gastrointestinal tract and respiratory tract, inhibits the histamine vasoconstricting effect of major vessels and vasodilating effect of venules and arterioles. It also inhibits the increase in capillary permeability caused by histamine. Antihistamine has no effect on gastric secretion secondary to histamine stimulation. Since it acts by competitive inhibition and has no direct effects on the smooth muscles of the vasculature or the bronchial muscles, it has little therapeutic benefit in anaphylactic shock. Antihistamine also has no pharmacologic effect on other autacoids, and hence it is not used in the treatment of bronchial asthma.

Antihistamine can cause either CNS depression or stimulation depending on the dose and the individual (Table 36-1). Depressive symptoms include somnolence, lassitude, and fatigue. The aminolakyl ethers (i.e. diphenhydramine) are particularly prone to giving this side effect. CNS stimulative symptoms may include restlessness, nervousness, insomnia, and focal seizures in patients with previous cerebral lesions.

Table 36-1. Effects of Antihistamines

Derivatives Trade Names Effect

Ethanolamines Benadryl 4 + sedative effects (diphenhydramine) Dramamine 4 + atropine-like effects

Ethylendiamines Pyribenzamine 2 + sedative effects (pyrilamine) 4 + GI symptoms

Alkylamines Chlor-trimeton 1 + sedative effects (chlorpheniramine) Dimetane 2 + stimulation effects

Piperazines Cyclizine HCl 2 + sedative effects (chlorcyclizine) Marezine HCl Meclizine HCl Bonine HCl

Phenothiazines Phenergane 4 + control motion sickness. (promethazine)

1 Antihistamines also suppresses motion sickness. The diphenhydramine, promethazine, and piperazine derivatives are particularly effective in this regard. Promethazine and pyrilamine have mild local anaesthetic effects.

All antihistamines produce atropine-like activity giving rise to dry mouth, possible micturition problems, and impotence. It is possible to experience blurred vision, diplopia, euphoria, elevated blood pressure, anorexia, constipation or diarrhea, and epigastric distress from antihistamines. Antihistamines seldom cause allergic reactions although when used topically they may produce urticaria. Leukopenia and agranulocytosis have been reported. Piperazine compounds (i.e. cyclizine, chlorcyclizine, meclizine) have demonstrated teratogenic effects in experimental animals, and hence should be avoided during pregnancy. Antihistamine is usually contraindicated in patients taking MAO inhibitors.

When antihistamine is taken orally, the onset of action is about 15-30 minutes lasting 3-6 hours. It is metabolized mainly in the liver.

Acute poisoning, particularly in children, can be lethal. Patients may experience CNS stimulatory symptoms to include convulsions, ataxia, athetosis, and hallucinations. They then may elapse into coma and cardiorespiratory arrest in 2-18 hours. Treatment of antihistamine poisoning is supportive.

Commercial preparations have combined antihistamine with decongestive medications (i.e. phenylephrine hydrochloride). Sometimes preparations contain stimulants such as caffeine to counteract the depressive effects.

Drixoral: contains dexbrompheniramine maleate and d-iso-ephedrine sulfate

Dimetapp: contains brompheniramine (Dimetane) and vasoconstrictors (phenylephrine hydrochloride and phenylpropanolamine)

Actifed: contains Actidil (triprolidine HCl) and Sudafed (pseudoephrine HCl)

Ornade: contains Teldrin (chlorpheniramine maleate), phenylpropanolamine, and isopropamide iodide (drying agent)

Ornex: contains no antihistamine. It has acetaminophen, salicylamide, caffeine, phenylpropanolamine.

(Other can be found in the PDR.)

Anticholinergic Drugs

This group of drugs is considered by some to be the best established agents for the prevention of motion sickness. The mechanism of action is blocking of acetylcholine from its receptor sites. This action produces both peripheral and central effects such as blocking of the parasympathetic system, depression of smooth muscle activity, and depression of cerebral and medullary centers. Experiments with DFP (diisopropyl fluorophosphate, a potent anticholinesterase) provide evidence to suggest that the vestibular receptors are cholinergic.

2 Drugs in this category include scopolamine (Hyoscine), atropine, and the synthetic agents: amphetamine (Amphenadrine), cycrimine, and trihexyphenidyl. The most effective one is scopolamine. Scopolamine has fewer side effects than atropine and the synthetic belladona drugs. A dose of 0.6 mg of scopolamine appears to be best for suppression of motion sickness with minimal side effects. The side effects are:

1. Dry mouth. 2. Increase in pulse rate. 3. Drowsiness. 4. Headache. 5. Stomach awareness. 6. Nightmares. 7. Blurred vision. 8. Vertigo.

The addition of 10 mg of d-amphetamine to 0.6 mg of Hyoscine may decrease the side effect of drowsiness. The onset of therapeutic action is approximately 1 hour after the medication is given, the duration of action is approximately 4 hours.

Phenothiazines

This group includes prochlorperazine (Compazine), chlorpromazine (Thorazine), promethazine (Phenergan), perphenazine (Trilafon), trifluoperazine (Stelazine), and promazine (Sparine). Phenergan is the best in this group for controlling motion sickness. It also can be classified as an antihistamine. It is also a hypnotic which means its side effect is drowsiness. The duration of action of phenergan is about 6 hours. An amphetamine can be added to combat the drowsiness.

Vasoconstrictors

Epinephrine

1. It stimulates the sympathetic nervous system. 2. It increases tone and vasoconstriction as evidenced by marked pallor and shrinkage of the mucous membrane. 3. It is vagolytic and antagonistic toward the parasympathetic nervous system. 4. It is a bronchial dilator. 5. Its onset of action is only a few minutes after subcutaneous injection. Its action lasts 1 hour.

Dosages:

0.05-0.1 mL infants 0.15-0.25 mL up to 8 years old 0.3-0.5 mL older children and adults 6. It is irritating to the nasal mucosa. Phenylephrine (Neo-Synephrine) and ephedrine are less irritating. 7. It cannot be given orally.

3 Ephedrine

1. It stimulate the peripheral sympathetic system and the CNS. It thus produces insomnia, palpitation, and nervousness. 2. It can depress the heart giving rise to extrasystoles. 3. It may cause urinary retention. 4. It can be given orally.

Neo-Synephrine (Phenylephrine)

Phenylephrine is a synthetic ephedrine.

Isuprel (Isoproterenol)

1. It does not have the excitatory and pressor effects of epinephrine. 2. It can be given sublingually, orally, and it can be inhaled. 3. Overdosage can cause bronchial spasm instead of bronchial dilation.

Topical Vasoconstrictors

These agents include:

Propylhexedrine (Benzedrex) Naphazoline (Privine) Oxymetazoline (Afrin) Tetrahydrozoline (Tyzine) Xylometazoline (Otrivine).

Steroids

1. The adrenal cortex secretes:

a. Glucocorticoids, i.e. hydrocortisone.

b. Mineralocorticoids, i.e. aldosterone.

1) Glucocorticoids have the following properties:

a) Increase gluconeogenesis.

b) Decrease the sensitivity of tissue to the action of insulin.

c) Increase protein catabolism.

d) Increase diuresis of water.

e) Delay wound healing.

4 f) Retard growth centers.

g) Inhibit formation of fibroblasts and tissue vascularization.

h) Alter the union of antibody and antigen.

i) Increase the plasma level of the oxidase enzyme which degrades histamine.

j) Suppress the secretion of ACTH from the anterior pituitary gland.

2) Mineralocorticoids have no anti-inflammatory properties and cause Na retention and K secretion: i.e. Aldosterone.

2. Clinically, it is better to administer glucocorticoids than ACTH because the patient may be allergic to the ACTH extract, and further ACTH depresses pituitary function.

3. When indicated, the use of corticosteroids should not replace the use of epinephrine since corticosteroids are not effective till 60-120 minutes after administration even when given intravenously.

4. Normal daily secretion of glucocorticoids is 20 mg of cortisone a day or 5 mg prednisone a day.

Table 36-2 lists some commonly used steroids, their trade names, and properties.

Table 36-2. Commonly Used Steroids

Generic Name Relative Dosage Cushingoid or Gluconeogenic Naret Trade Name Anti-inflammatory Properties

Hydrocortisone 20 mg 1 1 Solu-Cortex 1 Cpd F

Cortisone 25 mg 1 1 Cpd E 0.8

Prednisone 5 mg 5 0.8 3-5

Prednisolone 5 mg 5 0.8 Delta-Cortef 3-5

Triamcinolone 4 mg 20 0 Aristocort 20 Kenacort

Dexamethasone 0.75 20 0

5 Decadron 20-30

Methylprednisone 4 mg 10 0 Medrol 10 Solu-Medrol

Betamethasone 0.6 mg 20 0 25

Antibiotics

1. Competitive Antagonist: i.e. sulfonamide is a structural analogue of para- aminobenzoic acid (PABA) and PABA is needed for folic acid synthesis in the bacteria.

2. Inhibition of Cell Wall Synthesis: i.e. penicillin, cephalothin (Keflin), bacitracin, vancomycin, novobiocin, cycloserine.

3. Inhibition of Cell Membrane Function: i.e. polymyxin (colistin) on gram-negative organisms, polyenes on fungi.

4. Inhibition of Protein Synthesis: i.e. chloramphenicol, tetracycline, streptomycin, and erythromycin.

5. Inhibition of Nucleic Acid Synthesis: i.e. actinomycins and griseofulvin.

6. Sulfonamides: Bacteriostatic. Penicillin: Bactericidal in high concentrations and bacteriostatic in low concentrations. Cephalosporin: Bactericidal. Streptomycin: Bactericidal. Tetracycline: Bacteriostatic and rickettsiostatic. Chloramphenicol: Bacteriostatic. Bacitracin: Bactericidal (when used systemically, it is toxic to the kidney causing tubular and glomerular necrosis). Neomycin: Bactericidal. Kanamycin: Bactericidal. Polymyxin B/E: Bactericidal (colistin). Vancomycin: Bactericidal. Erythromycin: Bacteriostatic or bactericidal. Lincomycin: Bacteriostatic or bactericifal. Cleocin (clinda): Bacteriostatic or bactericidal.

7. Sulfa drugs and hemophilic streptococcal infections can give rise to secondary anemia.

8. Phenylalanine helps to combat the agranulocytosis encountered in patients receiving chloramphenicol (Chloromycetin).

6 9. Tetracycline potentiates the hypoglycemic effects of oral hypoglycemic agents.

10. Probenecid (Benemid) inhibits the tubular secretion of penicillin thus increasing the plasma levels.

11. Lincomycin (Lincocin) may cause severe diarrhea with blood and mucus in the stool. Fatal colitis may ensure. The same applies to clindamycin (Cleocin).

12. Chloromycetin may cause aplastic anemia, hypoplastic anemia, thrombocytopenia, and granulocytopenia. There are reports of aplastic anemia that terminated in leukemia following administration of chloromycetin. Blood dyscrasias have been reported following short- and long-term therapy.

Ototoxicity

Salicylates

Salicylates cause a reversible hearing loss and tinnitus. It has been postulated that salicylates exert an uncoupling action on oxidative phosphorylation. They inhibit various transaminases and dehydrogenases. In humans, discontinuation of high doses of the drug will cause the salicylate level to fall as the drug is excreted and the hearing reverts to normal within 24-72 hours. No histologic changes have been demonstrated. To cause toxicity, 6-8 g/day have to be taken. Salicylates are rapidly metabolized in tissues and approximately 50% is eliminated in 24 hours. Within 48-72 hours all salicylates will have been excreted in the urine.

Salicylate serum levels of 20 mg% or higher will cause hearing loss. The higher the serum level (up to 50 mg%) of salicylate, the greater the hearing loss.

Aspirin is found in the following medications: Percodan, Fiorinal, Coricidin, Trigesic, Norgesic, Talwin Compound, and Equagesic.

Dihydrostreptomycin

Dihydrostreptomycin can cause severe and erratic hearing loss even as long as 2 months after the medication has been stopped. The hearing loss is unpredictable and not dose related. Since this drug has no advantage over streptomycin sulfate, it never should be used. In the United States, it has been taken off the market.

Streptomycin

Streptomycin sulfate causes vertigo before the onset to tinnitus and hearing loss. Its affinity for the vestibular over the auditory system has been capitalized on to treat intractable bilateral Ménière's disease. For this purpose an average dosage of 2 g/day is given until no caloric response is obtained upon stimulation with ice water.

7 The vestibular toxic effect of streptomycin sulfate is dose related.1gq.d.for10days does not give vestibular symptoms. However,2gq.d.for14days has been reported to give vestibular symptoms in 60-70% of the patients.

Fifty to sixty percent of streptomycin sulfate is excreted by the kidneys in the first 24 hours. The larger the dose the faster the excretion by a normal kidney. Hence, any renal impairment will build up the serum level very quickly. A very small amount is secreted by the liver to be excreted through the gastrointestinal tract.

Peak plasma level is detectable within 1 or 2 hours after IM injection and diminishes by about 50% in 5 hours. The antibiotic can be detected in the plasma for at least 8-12 hours after administration. Recommended doses for children are 15-30 mg/kg/day.

Histologic findings following ototoxicity due to streptomycin are:

a. Minimal scattered loss of outer hair cells in the upper basal turn of the cochlea. Normal supporting cells.

b. Severe damage to the sensory epithelium of the cristae of all canals. Severe hair cell loss and flattening of the sensory epithelium of the cristae and saccule. The utricular macula is involved but least so in the vestibular end organs.

c. Stereocilia in the canal ampullae are swollen and are twice their normal diameter.

Kanamycin

Kanamycin may not be as ototoxic as neomycin. However, in patients with poor renal function, its administration has to be justified and the minimal necessary dosage used. In adults with good renal function, 15 mg/kg/day will cause mild or no hearing loss.

Kanamycin is poorly absorbed orally. Inframuscular administration of 1 g yields a peak plasma level of 20-35 microg/mL in about 1 hour. In 12 hours, the level falls to 1.2 microg/mL. Fifty to eighty percent of this drug is excreted by the kidney in 24 hours. In patients with normal kidney function, repeated injections of kanamycin should not lead to accumulation of the drug. Kanamycin is also nephrotoxic.

Histologic findings following ototoxicity due to kanamycin are:

a. Destruction of inner and outer hair cells. The latter are believed to be destroyed first. A more severe hair cell degeneration is found in the basal turn, the apical turn being less involved.

b. The supporting cells usually are not altered. Hence, neural degeneration is insignificant.

c. Normal semicircular canal cristae and maculae of the utricle and saccule.

8 Neomycin

Neomycin is not absorbed well topically or orally. Therefore, using neomycin orally to sterilize the bowel carries little risk of ototoxicity. However, repeated use of neomycin over inflamed gastrointestinal mucosa has caused irreversible deafness.

Five to eight grams given parenterally over 4-6 days have caused tinnitus and irreversible hearing loss. A 1 g parenteral dose will give a plasma level of 20 microg/mL for 6-8 hours. Neomycin is secreted by the kidneys. Hence, when renal disease is present, neomycin should be withheld because of its potential for nephrotoxicity.

Neomycin, dihydrostreptomycin, and kanamycin are eliminated more slowly from the inner ear than from the rest of the body, resulting in delayed ototoxicity. Hearing loss as a result of neomycin ototoxicity may occur as late as 1-2 weeks after the drug is stopped. The following histologic findings have been noted in neomycin ototoxicity:

a. Destruction of inner and outer hair cells, the outer ones being slightly less involved. Apical and basal turns are both involved, the basal turn being more so than the apical turn.

b. Some destruction of pillar cells is present with some atrophy of the stria vascularis.

c. A minimal loss of Deiters' cells and Hensen's cells.

d. Maculae and cristae remain normal.

Ethacrynic Acid

This diuretic has been demonstrated to cause destruction of the intermediate layer of the stria vascularis and outer hair cells of the organ of Corti, most severe in the basal turn. The hearing loss can be transient or permanent. The transient hearing loss could be secondary to its effect on the respiratory enzyme (succinodehydrogenase and adenosine triphosphatase) in the organ of Corti and stria vascularis. It apparently decreases the sodium content of the endolymph. The symptoms include hearing loss, tinnitus, and vertigo.

Quinine

Quinine is readily absorbed when taken orally. Ninety-five percent of the drug is metabolized in the liver so no untoward effects are feared in the event of renal disease. Most of the drug is excreted in 24 hours. The usual dosage is 0.3-0.6 g q.i.d. The ototoxic effects of quinine are hearing loss and tinnitus, both of which are reversible. The ingestion of quinine in therapeutic doses may not give rise to hearing loss in the mother, but may affect the fetus, giving rise to severe bilateral sensorineural hearing loss. Histologically, the external hair cells and stria vascularis have been noted to be atrophied. The brain stem vestibular and cochlear nuclei have been noted to tbe normal. Takin chloroquine in pregnancy is similarly hazardous to fetus.

9 Gentamicin

Gentamicin affects the vestibular nuclei rather than the auditory system. If used at serum levels of 10-12 microg/mL, it does not cause any ototoxicity. The recommended dosage is 1 mg/kg/day. In patients with renal damage, this dose should be adjusted.

Nitrogen Mustard

Nitrogen mustard causes destruction of hair cells giving rise to sensory hearing loss.

Tobramycin

Tobramycin has ototoxic effects similar to kanamycin. The hearing loss consists of a high-frequency hearing loss that produces a steeply sloping audiogram. The vestibular symptoms are less common.

Cisplatin

Cisplatin may give rise to high-tone hearing loss. Temporal bone studies reveal a loss of outer hair cells of the basal turns.

Misonidazole

Misonidazole is a new potent antitumor agent that selectively increases the effect of ionizing radiation on poorly oxygenated tumor cells. It can cause sensorineural hearing loss of cochlear origin.

Other ototoxic drugs include: polymyxin B, colistin, viomycin, vancomycin, ristocetin, arsenicals, oils of Chenopodium, chloroform, iodoform, alkaloids (strichnine, opiates, pilocarpine, scopolamine), and tetanus antitoxin.

Neurologic Medications

1. Sodium diphenylhydantoin (Dilantin): It stabilizes seizure activities and prevents the spread of seizure activities.

2. Carisoprodol (Soma) is a muscle relaxant. It acts by blocking the interneuronal activity in the descending reticular formation and spinal cord.

3. Ergotamine tartarate (Sansert) selectively constricts cerebral vessels thus relieving the headache from cerebral vascular dilation.

4. Carbamazepine (Tegretol) is used for genuine trigeminal neuralgia. Death from aplastic anemia (agranulocytosis, thrombocytopenia, leukopenia) has been reported. Its mechanism of action is unclear.

10 Chemotherapeutic Agents

Folate Antagonist (Methotrexate)

1. Inhibits DNA synthesis.

2. Binds and inhibits dihydrofolate reductase.

3. Single most effective drug against squamous cell cancer in the head and neck.

4. Major toxicity: bone marrow (reversible), gastrointestinal tract, and kidneys (in patients with impaired function).

Antibiotics

1. Doxorubicin (Adriamycin).

a. Interferes with both DNA and RNA synthesis.

b. Binds to DNA.

c. Major toxicity: cardiovascular.

2. Bleomycin.

a. Inhibits DNA synthesis.

b. Binds to DNA and causes splits in strands of DNA.

c. Major toxicity: pulmonary.

Pyrimidine Analogues (5-fluorouracil)

1. Blocks DNA synthesis.

2. Inhibits thymidylate synthetase.

3. Major toxicity: bone marrow, gastrointestinal tract, oral mucosa.

Alkylating

1. Mustard drugs.

a. Nitrogen mustard, melphalan, chlorambucil, cyclophosphamide.

b. Interfere with mitosis and cell division.

11 c. Their metabolism stimulates the formation of a highly reactive carbonium ion which most frequently alkylates the purine.

d. Major toxicity: lymphotoxicity, gastrointestinal irritation, alopecia, cystitis.

2. Nonmustard alkylating drugs.

a. Nitroureas (CCNUY, methyl CCNU), thiotepa, BCN4, and dicarbazine.

b. Inhibit DNA, RNA, and protein synthesis.

c. Major toxicity: myelosuppression, gastrointestinal.

Cysplatin

a. Inorganic metallic salt.

b. Mode of action unknown.

c. Major toxicity: bone marrow, kidney, gastrointestinal, cochlear.

12 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 37: Miscellaneous Information

Relevant Anatomy of the Head and Neck

1. Blood supply to the tonsil

a. Facial artery: tonsilar branch (most important) ascending palatine branch

b. Lingual artery: dorsal lingual artery

c. Internal maxillary artery: descending palatine and greater palatine arteries

d. Ascending pharyngeal artery.

2. Blood supply to the adenoids

a. Facial artery: to ascending palatine artery

b. Ascending pharyngeal artery

c. Internal maxillary artery: to pharyngeal branch

d. Thyrocervical trunk: to ascending cervical branch.

3. There are three dehiscences or weak spots through which an esophageal diverticulum can take place:

a. Killian's dehiscence: between the cricopharyngeus and thyropharyngeus muscles.

b. Lamier Hackeman's space: between the circular and longitudinal fibers of the esophagus.

c. Kilian-Jameison space: between the cricopharyngeus and the circular fibers of the esophagus.

4. Cranial nerve central connection

CN I: Subcallosal, hippocampal gyrus, uncus area. This first cranial nerve receives crossed an uncrossed fibers.

CN III: a. Motor nucleus (also known as lateral nucleus, medial nucleus of Perlia) to the extraocular muscles and levator palpebrae superioris.

1 b. Edinger-Westphal nucleus (parasympathetic nucleus, anterior medial nucleus) via the ciliary ganglion to the sphincter of iris and ciliary muscles.

CN IV: Motor nucleus (crossed fibers only) to extraocular muscle.

CN VI: Motor nucleus (uncrossed fibers only) to extraocular muscle.

CN V: a. Semilunar ganglion (main sensory nucleus). Gasserian ganglion to somatic sensory fibers.

b. Mesencephalic nucleus to kinesthetic sense from teeth and jaws.

c. Motor nucleus (crossed and uncrossed fibers), i.e. masticator muscles, tensor tympani, tensor palati muscle, and anterior belly of the digastric muscle.

d. Spinal nucleus of V - receives pain and temperature impulses from face, dura, and portions of ear via VII, IX, X.

CN VI (abducens):

a. Motor nucleus in lower pons via uncrossed fibers via longest intracranial course to lateral rectus.

b. From both cortexes to motor nucleus for upper face.

CN VII (facial): a. From contralateral cortex to motor nucleus for lower face, via facial nerve to stapedius muscle, posterior belly of digastric, muscles of facial expression.

b. Superior salivatory nucleus via nervus intermedius, greater superficial petrosal nerve to nasal, lacrimal glands, or chorda tympani to submandibular glands.

c. Nucleus of tractus solitarius - fibers from geniculate ganglion from chorda tympani containing taste from anterior two-thirds of tongue.

d. To spinal tract of V with sensory fibers from concha.

VIII (auditory): a. Cochlear - dorsal and ventral nuclei.

b. Vestibular - superior, medial, lateral and inferior (spinal) nuclei.

CN IX: a. Ambiguus nucleus (motor) via stylopharyngeus inferior salivatory nucleus to Jacobson's nerve to otic ganglion to parotid gland. Tractus solitarius nucleus via inferior ganglion (petrosal) to deep sense and taste.

b. Sensory nucleus of the V nerve via superior ganglion (jugular) to somatic sensation.

CN X: a. Nucleus ambiguus (motor) to soft apalte and pharyngeal muscle.

2 b. Nucleus ambiguus via XI nerve bulbar portion to join the X nerve to recurrent laryngeal nerve to intrinsic laryngeal muscles.

c. Dorsal motor nucleus (parasympathetic) to secretory fibers, regulates the heart rate and gastric peristalsis.

d. Sensory nucleus of V nerve via jugular ganglion (superior) yields somatic sensation to meningeal branch and auricular branch (Arnold's nerve).

e. Tractus solitarius via internal or medullary or bulbar branch to join the X nerve just outside the base of skull to recurrent laryngeal nerve.

b. C1 to C6 via external or spinal branch to trapezius and sternocleidomastoid muscle.

CN XII: Hypoglossal nucleus to intrinsic muscles of the tongue.

5. Cavernous sinus and superior orbital fissue syndromes (see Chap. 23). The superior orbital fissure transmits the ophthalmic vein, a branch of the middle meningeal artery, III nerve, IV nerve, frontal nerve of V1, lacrimal nerve of V1, nasociliary nerve of V1 and VI. The inferior orbital fissure transmits the zygomatic nerve and sphenopalatine twigs (parasympathetic) to the lacrimal gland.

6. a. The superior constrictor muscle spans from the median raphe and the the pharyngeal tubercle of the occipital bone to the pterygomandibular ligament, mandible, and medial pterygoid plate.

b. The medial constrictor muscle spans from the median raphe to the hyoid bone and stylohyoid ligament.

c. The inferior constrictor muscle spans from the median raphe to the oblique line of the thyroid cartilage, cricoid and cricothyroid muscle.

7. The uvula has five muscles:

A. Palatopharyngeus (pharynx to soft palate).

b. Palatoglossus (tongue to soft palate).

c. Muscle uvula (posterior nasal spine to soft palate).

d. Tensor palati (sphenoid, medial pterygoid plate, eustachian tube to soft palate).

e. Levator palati (petrous, superior constrictor muscle, eustachian tube to soft palate).

8. The pterygomandibular raphe is between the buccinator and the superior constrictor muscles.

3 9. a. The ciliary ganglion is a parasympathetic ganglion. It receives preganglionic parasympathetic fibers from the Edinger-Westphal nucleus. The synapses are within the ganglion. The postganglionic fibers go to the ciliary muscles and the iris sphincter. It also receives the postganglionic sympathetic fibers on its way to the vessels within the eye. There is no sympathetic synapse within this ganglion. The nasociliary branch of V1 carries sensation back to the central nervous system via the ganglion. There is no synapse for this sensory innervation within the ciliary ganglion.

b. The sphenopalatine ganglion is a parasympathetic ganglion. It receives its preganglionic parasympathetic fibers via the greater superficial petrosal nerve from the superior salivatory nucleus. The postganglionic fibers innervate the lacrimal gland via the zygomatic nerve. Sensory nerves of V2 pass through it without any synapses. The sympathetic postganglion nerve also passes through it without synapse.

c. The submandibular ganglion also has synapses for the parasympathetic. The preganglionic fibers are from the superior salivatory nucleus via the chorda tympani. The post-ganglionic parasympathetic fibers go to the submaxillary gland. The sensory fibers are V3 and the postganglionic sympathetic fibers from the facial artery pass through it without synapses.

d. The otic ganglion also has synapsis for the parasympathetics. The preganglionic fibers are mainly from the inferior salivatory nucleus via Jacobson's nerve (branch of the IX nerve). A small contribution is from the superior salivatory nucleus via the lesser superficial petrosal nerve (branch of the VII nerve). The sensory branch of the V3 and the postganglionic sympathetic from the middle meningeal artery pass through this ganglion without synapses.

10. Contents of the skull foramina, fissures, canals, and sinuses.

a. Cavernous sinus.

1) Internal carotid artery.

2) CN III.

3) CN IV.

4) CN V.

6) CN VI.

b. Superior orbital fissure.

1) CN III.

2) CN IV.

3) CN VI.

4 4) Frontal nerve.

5) Lacrimal nerve.

6) Nasociliary nerve.

7) Ophthalmic vein. c. Inferior orbital fissure.

1) Zygomatic nerve.

2) Sphenopalatine branches. d. Optic canal.

1) Optic nerve.

2) Ophthalmic artery.

3) Central retinal artery. e. Carotid canal.

1) Internal carotid artery.

2) Carotid plexus of nerves. f. Jugular foramen.

1) Three compartments. a) Anterior. b) Posterior. c) Medial.

2) Anterior compartment - inferior petrosal sinus.

3) Posterior compartment. a) Jugular vein. b) Meningeal branches from the occipital and ascending pharyngeal arteries.

4) Medial compartment.

5 a) CN IX.

b) CN X.

c) CN XI.

g. Foramen lacerum.

1) Cartilage.

2) Vidian nerve.

3) Meningeal branch of the ascending pharyngeal artery.

h. Foramen ovale.

1) CN V3.

2) Small meningeal artery.

3) Small petrosal nerve.

i. Foramen rotundum.

1) CN V2.

j. Foramen spinosum.

1) Middle meningeal artery.

k. Hypoglossal canal.

1) CN XII.

11. The skull is made of cartilaginous as well as membranous bone. The cartilaginous bone contributes to:

a. Occipital.

b. Sphenoid.

c. Ethmoid.

e. Petrous.

The membranous bone contributes to:

a. Sphenoid.

6 b. Parietal.

c. Frontal.

d. Lacrimal.

e. Nasal bones.

f. Maxilla.

g. Mandible (may be partly enchondral from Meckel's cartilage).

h. Palate.

i. Zygoma.

j. Premaxilla.

k. Tympanic ring.

l. Squamosa.

m. Vomer.

n. Bony modiolus.

12. The orbital walls are made up of maxillary bone, frontal bone, ethmoid bone, zygomatic bone, sphenoid bone, and lacrimal bone. The lacrimal gland is in the zygomatic process of the frontal bone while the sac is in a fossa bound by the lacrimal bone and the fronal process of the maxilla. The zygoma has four processes:

a. Frontal.

b. Maxillary.

c. Toward the temporal bone.

d. To the greater wing of the sphenoid.

The maxilla has four processes:

a. Frontal.

b. Zygomatic.

c. Palatine.

d. Alveolar.

7 The mandible is the only facial bone capable of pathologic fracture.

13. Eighty-five percent of the superior thyroid arteries are derived from the external carotid artery while 15% of them are derived directly from the common carotid artery.

14. Referred otalgia:

a. Hypopharynx: via the jugular ganglion and Arnold's nerve of CN X.

b. Oral tongue: via the Gasserian ganglion and auriculotemporal nerve.

c. Base of tongue: via the petrosal ganglion and Jacobson's nerve.

15. Retromolar trigone:

a. Lateral (oblique line from the body of the mandible to the coronoid process.

b. Medial (extension of alveolar ridge to the coronoid process).

c. Anterior (posterior molar tooth).

16. The true cord is 1.7 mm thick. The most important laryngeal muscle for respiration and protection of the airway is the posterior cricoarytenoid muscle, the only laryngeal muscle which abducts the vocal cords.

17. The parapharyngeal space:

A. Boundaries.

1. Superiorly: base of skull.

2. Laterally: ramus of mandible, medial pterygoid muscle.

3. Posterolaterally: parotid fascia.

4. Medial: superior constrictor muscle, buccopharyngeal fascia.

5. Anteriorly: pterygoid fascia.

6. Posteriorly: carotid sheath.

7. Inferiorly: lesser cornu of the hyoid.

B. This basically describes a five-sided pyramid with the apex at the hyoid.

C. Three compartments:

1. Prestyloid compartment.

8 2. Retrostyloid compartment.

3. Retropharyngeal compartment.

D. Contents of each compartment.

1. Prestyloid compartment. a. Internal maxillary artery. b. Inferior alveolar, lingual and auriculotemporal nerves.

2. Retrostyloid space compartment. a. Internal carotid artery. b. Internal jugular vein. c. Cranial nerves IX, X, XI, XII. d. Cervical sympathetic chain.

3. Retropharyngeal compartment. a. Numerous lymph nodes. b. Node of Rouvière.

E. Communication to space of the head to which infection may spread.

1. Paralingual.

2. Parotid.

3. Carotid sheath.

4. Retropharyngeal.

5. Masticator.

6. Submandibular.

7. Potential spaces surrounding adjacent muscles.

8. Mediastinum via the retropharyngeal space.

F. Neurogenic tumours are the most common neoplasm in this space.

9 18. The jugular foramen is bound by the occipital bone medially and the temporal bone laterally.

19. Scalenus anticus: anterior tubercle of transverse process of C3, 4, 5, 6 to first rib.

Scalenus medius: posterior tubercle of transverse process of C1, 2, 3, 4, 5, 6, 7 to first rib.

20. Branches of the external carotid artery.

A. Superior thyroid artery.

1. Infrahyoid a.

2. Superior laryngeal a.

3. Sternomastoid branch.

4. Cricothyroid branch.

B. Lingual artery.

1. Suprahyoid a.

2. Dorsalis linguae.

3. Sublingual a.

4. Ranine a.

C. Facial artery.

1. Cervical branches.

a. Ascending palatine.

b. Tonsillar a.

c. Submaxillary a.

d. Submental a.

e. Muscular branches.

2. Facial branches.

a. Muscular branches.

10 b. Inferior labial a. c. Inferior coronary a. d. Superior coronary a. e. Lateral nasal a. f. Angular a.

D. Occipital artery.

1. Muscular branches.

2. Sternomastoid a.

3. Auricular a.

4. Meningeal branches.

5. Arteria princeps cervicis.

E. Posterior auricular artery.

1. Stylomastoid branch.

2. Auricular branch.

3. Mastoid branch.

F. Ascending pharyngeal artery.

1. Prevertebral branches.

2. Pharyngeal branches.

3. Tympanic branches.

4. Meningeal branches.

G. Superficial temporal artery.

1. Transverse facial a.

2. Middle temporal a.

3. Anterior auricular branches.

11 H. Internal maxillary artery.

1. Maxillary portion.

a. Tympanic branch.

b. Deep auricular branch.

c. Middle meningeal a.

d. Small meningeal a.

e. Inferior dental a.

2. Pterygoid portion.

a. Deep temporal branches.

b. Pterygoid branches.

c. Masseteric a.

d. Buccal a.

3. Sphenomaxillary portion.

a. Alveolar a.

b. Infraorbital a.

c. Descending palatine a.

d. Vidian a.

e. Pterygopalatine a.

f. Sphenopalatine a.

Relationships of the Anterior and Posterior Ethmoid Arteries

The anterior ethmoid artery is found in the frontal ethmoid suture at about 15 mm posterior to the maxillolacrimal suture line.

The posterior ethmoid artery is 4-7 mm from the optic nerve.

12 Histology and Pathology

As in the previous section, it is not the intent of this chapter to cover histology and pathology of the head and neck. The chapter highlights the areas that may be appropriate in this type of synopsis.

1. Lining epithelium:

Middle ear = nonciliated cuboidal epithelium in general, though in the area near the eustachian tube orifice, the epithelium may be ciliated cuboidal.

Eustachian tube = pseudostratified ciliated columnar epithelium with goblet cells.

Mastoid and epitympanum = pavement epithelium without cilia.

Endolymphatic duct and proximal portion of the sac = vilous and lined by columnar epithelium.

Distal sac = smooth and lined by cuboidal epithelium.

Nose:

a. Lower two-thirds of the septum, lateral wall below the superior turbinate = respiratory epithelium (pseudostratified ciliated, columnar epithelium with irregular basal cells and goblet cells) - Schneiderian epithelium.

b. Upper one-half of the septum, lateral wall above superior turbinate and "roof" of the nose = pseudostratified, nonciliated, columnar epithelium with serous glands of Bowman; bipolar olfactory cells as well as supporting and basal cells.

c. Vestibule = stratified, squamous epithelium with some glands.

Nasopharynx:

a. Upper one-half = ciliated columnar.

b. Lower one-half = nonkeratinizing epidermoid epithelium.

Paranasal sinuses and nasolacrimal duct = respiratory epithelium.

Between the oral pharynx and nasopharynx = transitional cells.

Oropharynx and laryngopharynx = stratified squamous epithelium.

Palatine tonsils = squamous epithelium.

Adenoid = ciliated columnar epithelium.

13 Lingual tonsil = squamous epithelium (striated muscular fibers are usually seen in the specimen).

Larynx.

a. True cord, false cord, upper two-thirds of epiglottis, aryepiglottic folds = nonkeratinizing stratified squamous epithelium.

b. The rest = pseudostratified ciliated columnar epithelium.

Mucous glands are found in the ventricle, saccule, posterior surface of the epiglottis, and margin of the aryepiglottic folds.

Trachea and bronchi = pseudostratified ciliated columnar epithelium with goblet cells.

Upper two-thirds of the esophagus = stratified squamous epithelium with inner circular muscular layer and outer longitudinal muscular layer.

Lower one-third of the esophagus = villous type of columnar epithelium with the same muscular layers.

2. Antoni type A: This arrangement is found in neurogenic tumours. The cells are arranged in palisade or picket fencelike arrangements with the formation of the so-called Verocay bodies. These cells are delicately intertwined with connective tissues and reticular fibrils.

Antoni type B: This has a less orderly architectural formation. The Schwann's cells are haphazardly dispersed within the loose reticular fibrils and small cystic spaces. This also is found in neurogenic tumors. Neurogenic tumor is the most frequently found benign primary tumor in the parapharyngeal spaces.

3. Learn to differentiate between hemangioma, pyogenic granuloma, and hemagiopericytoma.

4. Ameloblastoma (see Chap. 20): Histologically, it consists of a meshwork of interlacing wide strands and islands of epithelial tumor cells in a moderately cellular conective tissue stroma. The periphery is lined with palisading large cells, columnar or cuboidal.

5. Warthin-Finkeldey giant cells are found in the lymphoid tissues in measles.

6. Actinomyces sp. are frequently found in tonsillar specimens. These are considered saprophytes with little clinical significance.

7. Chordoma (neuroectodermal cell origin) has physaliferous cells. Chordoma is not radiosensitive.

8. Granular cell myoblastoma can give rise to pseudoepitheliomatous hyperplasia in the larynx. Three percent of granular cell myoblastoma progress to malignancy. In order of

14 decreasing frequency of involvement: tongue, skin, breast, subcutaneous tissues, respiratory tract.

9. Inverted papilloma (schneiderian papilloma, transitional cell papilloma, Ewing's papilloma, or cylindrical cell papilloma): The cells are rich in glycogen. Thirteen percent of nasal inverted papilloma progress to malignancy; even the histologically benign category is locally invasive. It usually arises from the lateralnasal wall rather than from the septum. The treatment of choice is wide excision through a lateral rhinotomy approach.

10. Mixed tumor is the most common parotid tumor in the general population, next is the mucoepidermoid tumor. Seventy-five percent of mucoepidermoid tumors are clinically benign. In children, hemangioma or lymphangioma is most common followed by benign mixed, then mucoepidermoid.

11. Rhinoscleroma has Mikulicz's cells and Russel fuchsinophile bodies. It also can give rise to pseudoepitheliomatous hyperplasia of the larynx. The treatment of choice is presently sulfonamides and antibiotics (streptomycin, ampicillin, or tetracycline). The causative agent is Klebsiella rhinoscleromatis (von Frisch's bacillus). The primary site is the anterior nares. There are three stages in this disease: first, atrophic; second: nodular, and third: stenotic. Symptoms include foul, purulent rhinorrhea.

12. The Reed-Sternberg cell is found in Hodgkin's disease but not in lymphosarcoma or reticulum cell sarcoma.

13. Tympanosclerosis is a hyaline-fibrosclerotic lesion due to a nonspecific degenerative inflammatory process.

14. Children with idiopathic respiratory distress syndrome (hyaline membrane disease) lack a surface active material called surfactant. The major component of surfactant is alpha- lecithin.

15. I. Causes of Abnormal Serum Calcium Levels

A. Hypocalcemia

1. Hypoparathyroidism.

2. Malabsorption syndrome.

3. Renal failure.

4. Acute pancreatitis.

5. Hypoproteinemia.

6. Pseudohypoparathyroidism.

15 7. Iatrogenic: secondary to removal of parathyroid glands during thyroid or head and neck cancer surgery.

B. Hypercalcemia.

1. Milk-alkali syndrome.

2. Vitamin D intoxication.

3. Sarcoidosis.

4. Multiple myeloma.

5. Primary hyperparathyroidism.

6. Secondary hyperparathyroidism for chronic renal failure.

7. Metastatic disease invading bone (i.e. breast cancer).

8. Pseudohyperparathyroidism: due to the reduction of parathormonelike proteins by head and neck or lung cancers.

II. Symptoms, Signs, and Treatment of Hypocalcemia

A. Hypocalcemia is a potential complication of neck surgery (most often the condition is transient and the symptoms are not severe).

B. Signs and Symptoms

1. Tetany, carpopedal spasms, Chvostek's sign, Trousseau's sign.

2. Seizures.

3. Confusion.

4. Prolonged QT interval on ECG.

C. Acute management

1. 20-30 mL of 10% calcium gluconate IV over 10-15 minutes.

2. Titrate to an appropriate serum calcium level - an IV drip of 10% calcium gluconate.

3. Vitamin D 100,000-200,000 units/day for severe hypocalcemia. Reduce dosage after 4 days since the drug accumulates in the body.

D. Chronic management.

16 1. 1800-2400 mg of elemental calcium per day (calcium gluconate is only 10% elemental calcium by weight; calcium lactate 13% free calcium).

2. Vitamin D 50,000 four times a day.

III. Calcitonin.

A. Produced by the C cells of the thyroid.

B. Actions.

1. Inhibits osteoclastic function (decreases bone resorption).

2. Stimulates osteoblastic function.

3. Promotes angiogenesis.

IV. Increased alkaline phosphatase activity implies:

1. Osteoblastic activity.

2. Liver disease.

3. Paget's disease.

4. Fracture.

5. Osteosarcomas.

6. Carcinoma of the prostate.

7. Metabolic bone diseases.

8. Metastatic bone disease.

9. Pregnancy.

16. Thyroid adenoma may present as a calcified mass in the neck. Papillary carcinoma of the thyroid may have "psammoma bodies". Medullary carcinoma of the thyroid gland has amyloid deposits and is thyrocalcitonin producing.

17. Fibrous dysplasia

A. Etiology unknown.

B. Two presentations:

1. Monostotic.

17 a. More common than the polyostotoc form.

b. Usually involves either the frontal or sphenoid bones.

2. Polyostotic.

a. Female preponderance.

b. Sexual precoccity.

c. Skin lesions.

C. Presents during childhood and arrests when growth is complete.

D. Common findings:

1. Ptosis.

2. Exophthalmos.

3. Decrease of visual acuity.

4. Cosmetic deformities.

5. Hearing loss.

E. Bony involvement:

1. Sphenoid and frontal bones, 50%.

2. Optic canals, 20%.

3. Cranial and temporal bone involvement have been reported.

F. Alkaline phosphatase elevated.

G. Treatment:

1. Curettage.

2. Partial resection.

3. Optic nerve decompression.

18. Biochemical byproducts of metabolic disorders.

a. Mucopolysaccharide content is increased in exophthalmic tissues as well as in hypothyroidism.

18 b. Chondroitin sulfate is found in urine in Hurler's syndrome.

c. The cells of inverted papilloma have an increased glycogen content.

d. Hypothyroid cells also have an increased hyaluronic acid content.

e. The patients with oculopharyngeal syndrome have an increased cellular content of creatinine phosphokinase.

f. Rhabdomyosarcoma cells have increased glycogen content.

g. Relapsing polychondritis patients have an increased urinary content of mucopolysaccharide.

h. Trypsin is found in the stool of patients with mucoviscidosis.

19. Noma (gangrenous stomatitis): Usually starts at the mucous membrane of the corner of the mouth or cheek and spreads to involve the entire lip or cheek. The microorganisms found are: Borrelia sp., staphylococci, and anaerobic streptococci.

20. The most common benign tumor of the tonsil is squamous papilloma. Some investigators think this is precancerous.

21. Pemphigus: This is an uncommon disease characterized by bullae and erosions of skin, mucous membrane, acantholysis, chemical alterations in blood, and a high mortality. The etiology is unknown. This disease affects all races but with a higher incidence in the Jewish population. The age of onset is between 40-60 years old. There are intercellular attachments. Nikolski's sign is present - firm pressure on top of an intact blister results in extension at the edges.

Pemphigoid: This is a chronic bullous disease of unknown etiology. The bullar are smaller, more tense, and rupture less easily. Involvement of the mouth is less severe and less frequent than Pemphigus. The mortality is considerably lower. The bullae are subepidermal and acantholysis is absent.

22. Cherubism presents with painless, symmetric swelling of the posterior mandible and rami. Radiologically, it shows well-defined multilocular radiolucencies sometimes containing displaced teeth. There is a familial tendency. Pathologically, giant cell reparative granuloma with hemosiderin deposits are noted. There is no bone formation and no evidence of fibrous dysplasia. It is a self-limiting disease which ceases as the child reached puberty. Regression of the lesions and reshaping of the bone may leave minimal disfigurement.

23. Mikulicz's disease (see Chap. 17): There is an increased incidence of lymphoma and macroglobulinemia among these patients.

24. The most common submaxillary gland malignancy is "adenocystic carcinoma".

19 25. Hereditary lipoid proteinosis most commonly affects the larynx; next (in order of decreasing frequencies) are mastoid, tongue, thyroid, and nose.

26. The normal sweat chloride is less than 50 mEq/L, the normal zinc level is 90 mg%.

27. The lymphatic drainage of the palate is toward the retropharyngeal nodes, subdigastric nodes, and subparotid nodes.

28. Halisteresis: osteomalacia.

29. Ptyalism: excessive salivation.

30. Swallowing:

a. Five times per minute in the awake adult.

b. Once per minute in the sleeping adult.

c. Five times per minute in the sleeping infant.

31. Lead poisoning is characterized by abrupt onset of colic, constipation or diarrhea, anorexia, weakness, paralysis, coma, and convulsions. The erythrocytes show basophilic stippling. The lead level is usually greater than 0.08 mg/100 g of whole blood. The urinary level is 0.15 mg/L. There is increased delta-aminolevulinic acid and coproporphyrin III in the urine. Glycosuria is also present. Radiologically, there are linear opacifications parallel to the growing bone or circling the ossification centers.

Treatment requires removing the patient from further exposure to lead, increasing urinary output, and administering chelating agents (BAL with calcium disodium versenate).

32. Localized compact osteoma is most common in the frontal sinus. Localized cancellous osteoma is more frequently found in the maxillary and ethmoid sinuses. Fibrous dysplasia is most commonly found in the maxillary sinus.

33. Hyperostosis frontalis interna is a form of localized dysplasia limited to the inner table of the frontal bone and occurring mainly in elderly females. Headache may be associated with it. Obesity, dizziness, psychologic disturbances, and inverted sleep rhythm may be seen. The constellation of these findings is known as Morgagni-Stewart-Morel syndrome.

34. Hyperostosis with thickening of the bony walls of the skull is due to:

a. Chronic osteomyelitis.

b. Meningioma.

c. Osteoblastic metastasis.

20 d. Fibrous dysplasia.

e. Paget's disease.

f. Infantile cortical hyperostosis.

g. Albers-Schönberg disease (osteopetrosis).

35. Idiopathic histiocytosis (histiocytosis X group of diseases)

A. Proliferations of mature histiocytes.

B. Etiology unknown.

C. Three presentations:

1. Letterer-Siwe disease (prognosis = poor).

2. Hand-Schüller-Christian disease (30% mortality).

3. Unifocal eosinophilic granuloma (good prognosis).

D. Letterer-Siwe disease (acute disseminated histiocytosis, acute differential histiocytosis, nonlipid reticuloendotheliosis).

1. Acute, rapidly fatal illness.

2. Involve infants or young children.

3. Exfoliative dermatitis.

4. Hepatosplenomegaly.

5. Lymphadenopathy.

6. Anemia and thrombocytopenia.

7. Involvement of medullary cavities of bone, mucoa of the colon, and lung interstitium.

8. Rx: chemotherapy (steroids, alkylating agents, Vinca alkaloids, cytotoxic antibiotics.

E. Hand-Schüller-Christian disease (multifocal eosinophilic granuloma, chronic disseminated histiocytosis).

1. Chronic disorder with subacute presentation.

2. Usually affects young children but may be seen in adults.

21 3. Lytic lesions of the skull.

4. Acute mastoiditis, 2% with facial nerve weakness.

5. Intractable otitis media and all related complications.

6. External auditory canal polyp.

7. Proptosis.

8. Pituitary insufficiency (diabetes insipidus).

9. Mandible involvement with loss of teeth.

10. Lymphadenopathy.

11. Hepatosplenomegaly.

12. Ten percent with triad of DI, exophthalmos, and skull lesions.

13. Px: poor with involvement of heart, lung, brain, or pituitary.

14. Rx: as above.

F. Unifocal eosinophilic granuloma.

1. Benign disease.

2. Children and young adults may be involved.

3. Lytic lesions of the skull particularly of the temporal bone.

4. Tympanic membrane perforation.

5. Granulation tissue in the middle ear.

6. Acute mastoiditis.

7. Seventh nerve paralysis possible.

8. Proptosis.

9. Rx: curettage (steroid and radiation therapy may be considered).

36. Muclormycosis (see Chap. 14): It is caused by rhinocerebral phycomycosis.

22 37. Paralysis of the recurrent laryngeal nerve and the superior laryngeal nerve will cause a vocal cord to be in a cadaveric position. Paralysis of the recurrent laryngeal nerve alone will give rise to vocal cord in a paramedian position.

Ephemeral adductor paralysis is the same as mogiphonia which is stage fright aphonia. For more complete discussion of paralysis of the recurrent laryngeal nerve, see Chap. 15).

38. The carotid body is more sensitive to changes in oxygen tension than to changes in carbon dioxide tension, while the respiratory center is more sensitive to carbon dioxide changes than to oxygen changes. Hypoxemia is defined as PO2 below 40 mm Hg.

39. The least common type of tracheoesophageal fistula and atresia of the esophagus is one in which the upper end of the esophagus forms a fistula with the trachea while the lower end of the esophagus is not connected to the upper end of the esophagus nor to the trachea, it is a blind pouch. For more discussion of tracheoesophageal fistulae, see Chap. 16.

40. The cricoid is the most common origin of a cartilaginous tumor of the larynx.

41. Sodium uriate crystals are found in gout.

42. False-positive serology may occur in:

a. Malaria.

b. Leprosy.

c. Lupus.

d. Collagen disease in general.

e. Rheumatoid arthritis.

f. Measles.

g. Smallpox.

h. Hepatitis.

i. Infectious mononucleosis.

False-positive heterophile test may occur in:

a. Serum sickness.

b. Rheumatoid arthritis.

c. Hodgkin's disease.

23 d. Brucellosis.

e. Hepatitis.

43. Actinomycosis is treated with penicillin and tetracycline. Blastomycosis is treated with stilbamidine.

44. Olfactory neuroepithelioma is a malignant tumor of the olfactory mucous membrane; peak age is 11-20 years old. Treatment is primary surgical excision and radiation for residual tumor.

45. Acanthosis nigricans is an uncommon dermatosis characterized by hyperpigmentation and epidermal hypertrophy. The malignant form is associated with an internal cancer primarily adenocarcinoma. The benign juvenile form may be associated with metabolic disorders. Involvement is usually bilateral and symmetric and exhibits a propensity for flexural and intertriginous areas.

46. The eight nerve is covered with astrocytes and glial cells up to the entrance of the internal acoustic canal. Within the canal, this nerve is covered with Schwann's cells. Acoustic neurinoma arises from Schwann's cells and therefore theoretically acoustic neurinoma arises from within the internal auditory canal.

47. To be carcinocidal, the temperature for cryosyrgery needs to be at least -160°Cto -180°C.

48. Desmoid tumors are most commonly found in the abdominal wall and extremities. They are locally destructive and the treatment of choice is wide excision. Recurrence rates varies from 40-70%.

49. The triad of coughing, choking, and cuyanosis during feeding implies that the child has a tracheoesophageal fistula.

50. Causes for caseating necrosis include:

a. Tularemia.

b. Brucellosis (20% of patients with brucellosis present with hearing loss as well).

c. Tuberculosis or atypical tuberculosis.

d. Fungus.

51. Rhinosporosis is caused by Rhinosporidium seeberi, also called R. kinealyi.

53. Atrophic rhinitis:

A. Etiology unknown.

24 B. Female preponderance.

C. Associated bacteria:

1. Klebsiella ozaenae.

2. Corynebacterium diphtheriae.

3. Perez-Heter bacillus.

D. Histologic findings:

1. Squamous metaplasia.

2. Inflammatory infiltrates.

3. Scarcity of goblet cells.

4. Destruction of cilia.

E. Symptoms:

1. Nasal obstruction.

2. Epistaxis.

3. Anosmia.

4. Headaches.

F. Signs:

1. Offensive nasal odor.

2. Green crust.

3. Atrophy of turbinates.

G. Treatment:

1. Medical:

a. Saline irrigations.

b. Systemic antibiotics.

2. Surgical:

25 a. Endonasal microplasty: voume reduction of the nasal vault by submucosal implants. b. Young's operation: temporary closure of the nostrils.

53. Causes of anosmia:

a. Fractures of the cribriform plate.

b. Tumors of the frontal lobe or meninges.

c. Viral infections.

d. Nasal obstruction.

e. Drug toxicity.

f. Congenital defects of the nose.

54. Etiology of nasal septal perforations:

a. Trauma.

b. Surgery.

c. Atrophic rhinitis.

d. Syphilis.

e. Tuberculosis.

f. Wegener's granulomatosis.

g. Midline granuloma.

h. Heavy metal poisoning.

i. Lupus.

j. Tumors.

55. A calcified stylohyoid ligament occurs in 4% of the population.

56. Certain viruses have been incriminated as causing certain diseases:

RNA viruses

a. Picornavirus (enterovirus and rhinovirus).

26 b. Reovirus.

c. Arbovirus (encephalitis, yellow fever, dengue fever).

d. Myxovirus (measles, mumps, flu, croup).

DNA viruses

a. Papovavirus (papilloma of nose, pharynx, and larynx).

b. Adenovirus (URI).

c. Herpes (zoster, simplex, cytomegalovirus).

d. Poxvirus.

57. Most acquired choanal atresias are believed to be a result of tonsillectomy and adenoidectomy.

58. Keratotic papilloma is a wart.

59. Leukoplakia displays:

a. Parakeratosis.

b. Hyperkeratosis.

c. Dyskeratosis.

d. No pleomorphism.

e. No anaplasia.

f. No desmoplasia.

60. Definition:

Metaplasia: Change from one cell type to another.

Anaplasia: Reverting to more primitive cell type.

Desmoplasia: Connective tissue reaction to tumor.

Keratoacanthosis: Large acanthoma.

Pleomorphic: Occurrence in more than one form, existence in more than one morphologic type of cells.

27 Acanthosis: Increased thickness of prickle cell layer.

Parakeratosis: The nuclei migrated to the surface.

Dyskeratosis: The normal maturation sequence is disrupted and hence keratin is displaced in the wrong layer, i.e. in the prickle cell layer.

Hyperkeratosis: Increased keratin layer, i.e. this is found in pachydermal laryngitis.

61. Airway lengthening techniques:

a. Simple mobilization by blunt dissection of larynx and trachea-3cm.

b. Incision of the anular ligaments on one side of the trachea proximal to the anastomosis and on the opposite side distally - 1.5 cm.

c. Laryngeal release:

1. Two methods:

1. Release of the infrahyoid muscles (often accompanied by dysphagia).

2. Release of the suprahyoid muscles (dysphagia is infrequent)-5cm.

62. Brucellosis can be caused by Brucelle melitensis or B. abortus. It usually is transmitted by milk or by animals. The prognosis is good. Twenty percent of patients have sensorineural hearing loss.

63. Nevus:

a. Intra-epithelial = benign.

b. Junctional = premalignant.

c. Intradermal = benign.

d. Blue nevus = benign.

e. Mixed nevus = benign.

64. Congenital esophageal stenosis is most common at the junction between the middle and distal one-third of the esophagus. It is best treated with dilatation.

65. Tube feeding syndrome: Tube feeding syndrome usually results from too high a protein intake as well as too high a caloric intake. This results in excess osmotic load. This usually is accompanied by too little water intake. Consequently, dehydration ensues leading to hypernatremia, hyperchloremia, and azotemia. This is further compounded by a negative nitrogen balance in these patients. In response to this stress, the kidney compensates by

28 excreting concentrated urine to preserve water. Since little water is excreted, sodium and chloride also are retained causing further hypernatremia and hyperchloremia. In the presence of a high protein intake without adequate caloric intake, there is an increase in urea production leading to solid diuresis and dehydration. Diarrhea occasionally is noted with this syndrome. This pathophysiologic state will lead to mental deterioration, fever, tachycardia, neuromuscular irritability, and hyperreflexia. This most common complication from this syndrome is pneumonia, finally resulting in coma and death. The treatment is to rapidly decrease the protein and solute load and to increase fluid intake intravenously. The patient should be followed closely, along with daily electrolyte assay. Overaggressive treatment can lead to water intoxication.

6. Adequate urinary volume includes:

a. 10 drops/min.

b. 30 mL/hr.

c. 700 mL/day.

67. During an emergency in which an air embolism is suspected, the patient should be placed with the left side down.

68. Acidosis and vomiting can result from starvation after tonsillectomy in children. Treatment of this would be to encourage the intake of "sweets".

69. The symptoms of cardiac tamponade are:

a. Low cardiac output.

b. Muffled heart sounds.

c. Increased central venous pressure.

d. Decreased amplitude on ECG.

e. Definitive diagnosis made by pericardiocentesis.

70. Cerebral spinal fluid otorrhea.

a. Six percent of basilar skull fractures.

b. Ninety percent close spontaneously.

c. CSF leaks from the middle fossa close rapidly because the rich arachnoid mesh in that area promotes fibrosis and healing.

d. CSF leaks from the posterior fossa close more slowly since this area is relatively sparse in arachnoid tissue.

29 71. Indications to repair a CSF leak:

a. CSF leak that persists for longer than 2 weeks.

b. Recurrent meningitis.

c. Brain or meningeal herniation.

d. Penetration of brain by a bony spicule.

72. The complications of cholesteatoma in decreasing order of frequency are:

a. Fistula.

b. Extradural or perisinus abscess.

c. Serous or suppurative labyrinthitis.

d. Facial paralysis.

e. Meningitis.

f. Brain abscess.

g. Sigmoid thrombophlebitis.

h. Subperiosteal abscess.

73. Spread of cholesteatoma.

1. Cystic expansion.

2. Epithelial migration.

B. Cystic expansion.

1. Determined by:

a. Space available.

b. Negative pressure.

c. Internal desquamation.

2. Spread to available space:

a. Mesotympanic keratoma.

30 1) Originates from marginal or central perforations.

2) Passes underneath the lateral incudal fold.

3) Usually involves the posterior tympanum (i.e. facial recess, sinus tympani).

4) May enter the epitympanum by passing medial to the body of the incus.

5) Once in the epitympanum spread continues posteromedially to the aditus between superior mallear fold and the superior incudal fold.

b. Epitympanic keratoma:

1) Originates in the epitympanum from the pars flaccida.

2) Enters Prussak's space.

3) Three routes of egress from Prussak's space:

a) Posterior route:

(1) Most common route of spread.

(2) Ketaoma spread lateral to the body of the incus through a dehiscence between the lateral mallear fold and the lateral incudal fold and around the superior incudal fold and into the aditus.

b) Inferior route:

(1) Keratoma progresses via a dehiscence between the lateral and posterior mallear folds into the posterior pouch of von Troltsch (a space between the pars tensa and the posterior mallear fold) and into the mesotympanum.

c) Anterior route:

(1) Keratoma passes anterior to the neck of the malleus via a dehiscence in the anterior mallear fold into the anterior pouch of von Troltsch and into the protympanum.

3. Spread by negative pressure:

a. Negative pressure done to eustachian tube dysfunction is usually between -100 and

-400 mm H2O but may occasionally reach -600 mm H2O.

4. Spread by internal desquamation:

a. Keratoma arises from trapped squamous debris.

b. Often there is no evidence of infection.

31 C. Epithelial migration.

1. Migration through a perforation or an ulcer of an existing keratoma.

2. Epithelium follows the path of least resistance.

3. Keratoma invades vascular spaces within the ossicles.

74. Keratitis obturans vs. external canal cholesteatoma.

A. Keratitis obturans.

1. Otalgia.

2. Hearing loss.

3. Otorrhea is rare.

4. Often bilateral.

5. Erosion of the external canal.

6. Associated with bronchiectasis.

7. Usually young patients.

8. Rx: debridement.

B. External canal cholesteatoma:

1. No hearing loss.

2. Otorrhea is common.

3. Usually older patients.

4. Rx: Medical/surgical (modified radical mastoidectomy if mastoid is involved).

75. Hearing loss and head injuries:

a. Incidence of hearing loss with all head injuries, 33%.

b. Incidence of hearing loss in closed head injuries complicated by unconsciousness, 50%.

c. Of all the hearing losses, 30-80% will be sensorineural.

d. Of the hearing losses 15% will be conductive.

32 76. Seventh nerve paralysis due to head trauma:

a. Of all head trauma 0.7%.

b. In transverse temporal bone fractures 30-50%.

c. In longitudinal temporal boen fractures 10-20%.

77. Indications for myringotomy with acute otitis media (AOM):

a. Severe pain.

b. Patient with a complication of AOM (i.e. meningitis, brain abscess, etc).

c. Neonatal OM.

d. AOM not responsive to routine antibiotics.

78. Resonance frequencies of the ear:

Concha 5000-6000 Hz

EAC 3700 Hz

EAC and concha 2500-3000 Hz

ME 3000-5000 Hx

Modified radical mastoidectomy 2000-2500 Hz.

79. Auditory brainstem responses:

A. Wave I Eight nerve.

II Cochlear nucleus.

III Superior olivary nucleus.

IV Lateral lemniscus.

V Inferior colliculus.

VI Medial geniculate.

VII Auditory radiation.

B. Neonate:

33 1. Exhibit just three waves (I, III, V).

2. Have a normal increase in wave V latency until 1 year of age.

80. The fenestration operation restores hearing but lacks the transformer and lever mechanisms, thus leaves an unrestored conductive hearing loss of about 35 dB. Failure from the fenestration operation occurs within 2 years. If the hearing results are sustained for 2 years, it is most likely that it will be sustained forever. The osseous closure of the fenestration is rare if enchondralization as well as irrigation to remove the bone dust is done during the operation.

81. a. Mucopolysaccharide content is increased in exophthalmic tissues as well as in hypothyroidism.

b. Chondroitin sulfate is found in urine in Hurler's syndrome.

c. The cells of inverted papilloma have an increased glycogen content.

d. Hypothyroid cells also have an increased hyaluronic acid content.

e. The patients with oculopharyngeal syndrome have an increased cellular content of creatinine phosphokinase.

f. Rhabdomyosarcoma cells have increased glycogen content.

g. Relapsing polychondritis patients have an increased urinary content of mucopolysaccharide.

h. Trypsin is found in the stool of patients with mucoviscidosis.

82. Carcinoma of the tongue: Ninety-five percent of malignancies of the tongue are epidermoid. Malignant lesions of the oral tongue are three times as common as those of the pharyngeal tongue.

Among lesions of the oral tongue, the posterolateral border is the most frequent site. The middle one-third of the tongue is more frequently involved with malignancies than the anterior one-third.

83. Rates of lymph node metastasis in head and neck cancer:

A. Laryngeal cancer.

1. Glottic carcinoma:

a. Midmobile VC, 2%.

b. Anterior commissure with 5 mm of subglottic extension, 5-15%.

34 c. Fixed VC, 7%.

d. Delphian node, 5%.

2. Supraglottic carcinoma:

a. Epiglottis, 22-31% (14-16% occult).

b. Epiglottic and false cord, 55% (30% occult).

c. Supraglottis and true vocal cord, 53% (33%).

3. Subglottic carcinoma.

a. Primary subglottic cancer, 23%.

b. Glottic cancer with 5 mm subglottic extension, 23%.

4. Transglottic carcinoma:

a. In general 30-50% (20% occult).

b. Epiglottis and FVC and TVC, 50% (50% occult).

5. Hypopharynx carcinoma:

a. In general 66% (50% occult).

b. Aryepiglottic fold, 40% (33% occult).

6. Bilateral metastasis:

a. Usually seen in supraglottic or base of tongue tumors.

b. Supraglottic carcinoma, 5%.

c. Vallecula, 11%.

d. If an ipsilateral node is positive there is a 33% chance that a contralateral node will be positive.

B. Lip cancer:

1. T2, 52%.

2. T3, 73%.

C. Floor of the mouth carcinoma:

35 1. T2, 65%.

2. T3, 71%.

3. Occult nodes, 15%.

D. Buccal carcinoma:

1. Cervical metastasis, 50%.

E. Tongue carcinoma:

1. Anterior tongue: a. T2, 43%.

2. T3, 72%. c. Occult node, 65%.

2. Posterior tongue: 78%. a. Occult node, 19%.

F. Retromolar trigone:

1. Cervical metastasis, 60%.

2. Contralateral nodes, 23%.

84. Carcinoma of the lip:

a. Basal cell carcinoma.

1) Usually involves the upper lip.

b. Squamous cell carcinoma:

1) Usually involves the lower lip.

2) Upper lip lesions metastasize early.

3) Lower lip lesions metastasize infrequently (6-8% of cases).

85. Cartilaginous tumors of the larynx:

a. Chondromas and chondrosarcomas.

36 b. Generally males in their fourth through sixth decades are afflicted.

c. Cricoid cartilage most frequently involved.

d. Symptoms secondary to encroachment of the subglottic space.

e. Treatment is surgical:

1) Laryngectomy or hemilaryngectomy.

2) Treat chondromas and chondrosarcomas in a similar fashion.

f. Chondrosarcomas primarily metastasize by local invasion, but have been noted on rare occasion to metastasize to lung.

86. Extramedullary plasmacytoma:

a. Most appear in the head and neck (usually in the nasopharynx).

b. Usually involves middle-aged males.

c. Locally aggressive.

d. May evolve to myeloma.

87. Inverted papilloma:

a. Polypoid neoplasm of the lateral nasal wall (involvement of the nasal septum is rare).

b. Histologically benign but clinically invades adjacent structures.

c. Squamous carcinoma coexists in 13% of patients.

d. Actual degeneration to frank malignancy seen in only 2% of cases.

e. Male preponderance.

f. Treatment by wide surgical excision through a lateral rhinotomy approach.

g. High incidence of recurrence with inadequate surgery (25-75%).

88. Cervical metastases from the occult primary tumor:

a. Represent 4.7% of cases.

b. Squamous carcinoma is the predominant histological type.

37 c. Up to 90% of the primary lesions can be found by repeated examination and random biopsies or at autopsy (10% will never be found).

d. Usual site of primary tumor in determinant cases (in decreasing order of frequency):

1) Oronasopharynx (nasopharynx, base of tongue, and tonsil).

2) Larynx and hypopharynx.

3) Lung.

4) GI tract.

5) Thyroid gland.

e. Treatment:

1) RND alone, radiation therapy alone, or combined therapy.

f. Prognosis:

1) Five-year survival 30% regardless of type of treatment.

2) Prognosis is worsened if primary tumor is found.

89. Rhabdomyosarcoma of the head and neck:

a. Most common head and neck soft tissue malignancy in children.

b. Site of involvement (in decreasing order of frequency):

1) Orbit, 33%.

2) Neck.

3) Face.

4) Ear and mastoid, 7-10% each.

5) Tongue.

6) Palate.

7) Larynx: rare.

c. Attacks children in the first decade of life.

d. Grows rapidly.

38 e. Orbital tumors are locally aggressive but rarely metastasize; in contrast, other head and neck rhabdomyosarcomas metastasize more readily to lung, bone, brain, and other viscera by hematogenous routes.

f. Treatment includes surgery, radiation therapy, and chemotherapy.

g. Recent 3-year survivals are up to 80%.

90. Neurogenic tumors:

a. Two histologic patterns:

1) Antoni type A: A palisading pattern of nuclei above a central mass of cytoplasm (Verocay body) - picket fence appearance.

2) Antoni type B: Diffuse arrangement of nuclei and cytoplasm with no discenible pattern.

b. Both types are frequently seen within a single specimen.

c. The VIII nevre is covered with astrocytes and glial cells up to the entrance of the internal acoustic canal. Within the canal the VIII nerve is covered with Schwann's cells. Acoustic neurinoma arise from Schwann's cells and therefore, theoretically, acoustic neurinoma arises from within the internal auditory canal.

91. Paragangliomas (glomus tumors):

a. Site of involvement (in order of frequency):

1) Carotid body.

2) Jugulotympanic.

3) Intravagal.

4) Laryngeal.

5) Nasala.

6) Nasopharyngeal.

7) Orbital.

b. Multicentric in 10% of cases.

1) Associated with other malignancies in 8% of cases.

c. Familial tendency.

39 d. Incidence of metastasis is 2-6%.

e. Workup includes carotid and vertebral angiography and jugular venography.

f. Treatment: Surgical excision; radiation therapy may paliate nonoperative candidates.

g. Morbidity and mortality is most related to tumor size and location.

Order of morbidity:

1) Jugulare.

2) Tympanum.

3) Vagale.

4) Carotid body.

92. Craniopharyngioma.

a. Arise from a squamous cell nest in the region of the anterior pituitary gland (the embryonic Rathke's pouch area).

b. Clinical presentation:

1) Headaches.

2) Visual loss (bitemporal hemianopsia).

3) Optic atrophy.

4) Hypopituitarism.

5) Enlargement of the sella turcica.

6) Parasellar calcifications.

c. Differential diagnosis:

1) Optic glioma.

2) Pituitary tumors.

d. Treatment is controversial.

1) Total surgical excision.

2) Surgical debulking followed by 550-6500 rad.

40 93. Esthesioneuroblastoma.

a. Neurogenic tumor of the olfactory region.

b. Derived from olfactory epithelium.

c. Slow growing.

d. Local invasion and distant metastases possible.

e. Usually found in males during their second decade although all ages may be affected.

f. Sx:

1) Unilateral nasal obstruction.

2) Epistaxis.

3) Headache.

4) Rhinorrhea.

g. Px:

1) Surgery or radiation therapy alone: 45% 5-year survival.

2) Combined therapy: 67% 5-year survival.

94. Osteoma:

a. Benign slow-growing osteogenic tumor.

b. Usually found on the bones of the face or skull.

c. Common areas of growth (in decreasing order of frequency):

1) Mandible (usually in lingual surface of the ramus).

2) Frontal sinus.

3) Ethmoid sinus.

4) Maxillary sinus.

5) Sphenoid sinus.

d. Generally present as a painless mass.

41 e. May on occasion cause pain or invade the cranium.

f. Treatment:

1) Surgical excision.

g. Must consider Gardner's syndrome in the evaluation of the patient.

1) Autosomal dominant disease.

2) Patients present with osteomas, soft tissue tumors, and intestinal polyps.

3) Intestinal polyps may undergo malignant degeneration in 40% of patients with gastrointestinal symptoms.

95. Teratoma:

a. Tumors of embryonic origin.

b. Usually arise from basisphenoid near the midline.

c. Three types:

1) Dermoid.

2) True teratoma.

3) Epignathia.

d. Dermoid.

1) Polypoid masses with skin containing appendages ("hairy polyp").

2) Ectodermal and mesodermal components.

e. True teratomas.

1) All three germ layers represented.

2) Skull deformities are common.

3) Possible malignant degeneration.

f. Epignathus.

1) Well-differentiated "parasitic fetus" protruding from the mouth.

2) Patient usually dies.

42 g. Sx:

1) Respiratory distress.

2) Dysphagia.

3) Copious mucoid secretions.

96. Nasopharyngeal carcinoma: Because of its location, quite frequently presents first with a neck mass. Another common symptom is "blocked" ear secondary to serous otitis media.

97. The site of the "unknown" primary for a metastatic node in order of decreasing frequency is: nasopharynx, base of tongue, pyriform sinus.

98. The toluidine blue test: It stains mitotic lesions, mucin, food particles, and exudates a royal blue. It does not reveal submucosal extensions. Technique:

a. Rinse the mouth well.

b. Paint with 2% aqueous solution of toluidine blue.

c. Wait 30 seconds.

d. Rinse with warm water or 1% acetic acid to remove excess dye.

e. The positive areas are stained a royal blue.

99. Calcium gluconate = 9% free calcium (dosage: 12-15 g/day).

Calcium chloride = 27% free calcium (dosage: 6-8 g/day) (irritating to the stomach).

Calcium lactate = 13% free calcium (dosage: 10-12 g/day).

100. Fifty percent of myxedemic patients have reversible sensorineural hearing loss.

101. Amyloidosis gives a positive (metachromatic) crystal violet stain, and green birefringence with congo red stain.

102. Adenocystic carcinoma consitutes 6% of all salivary gland tumors.

103. A 99mTc scan will reveal Warthin3S tumor or oncocytoma as a "hot" nodule.

104. Papilloma of the oral cavity is most frequently seen in the faucial region. Some physicians consider them premalignant.

105. The incidence of carcinoma of the esophagus is increased in patients with:

43 a. Achalasia.

b. Oculopharyngeal syndrome.

c. Caustic burns.

d. Plummer-Vinson syndrome.

e. Pernicious anemia.

106. Herpangina: Etiology: Coxsackie A, characterized by minute vesicles in the anterior pillars of the fauces.

107. In achalasia, aspiration pneumonitis is a frequent complication. Prior to esophagoscopy, it is wise to first pass a nasogastric tube to remove the retained esophageal contents.

108. Leiomyoma is the most common benign tumor of the esophagus.

109. Scleroderma: This is a disease of unknown etiology perhaps secondary to some immune mechanism related to the connective tissues. The most common sites within the gastrointestinal tract are the esophagus and small bowel. The upper esophagus is not usually involved. This disease is more prevalent in females than in males. Physiologic abnormalities include decreased motility of the esophagus and esophagitis. Pathologically the mucosa and the submucosa are involved; however, the longitudinal muscles seldom are involved. A typical barium swallow will reveal a flaccid, dilated esophagus which is similar to that of achalasia. Dysphagia in 39%; decreased mouth opening in 28%; sicca syndrome in 80%.

Dermatomyositis: This is a nonsuppurative, nonhemorrhagic type of polymyositis in which cutaneous and muscle changes are noted. In the muscle, inflammatory reaction followed by granulation tissue invasion and hyaline degeneration is noted. The skin changes are nonspecific. Dysphagia occurs in most of the so-called collagen disorders, but it is encountered most frequently in dermatomyositis (60% of patients with dermatomyositis complain of dysphagia). Unlike scleroderma, there is no esophagitis in dermatomyositis. Decreased esophageal motility is present in both disorders.

Dermatomyositis Scleroderma

Dysphagia Pharyngeal Sternal Nasal regurgitation Frequent Absent Stage of disease Severe muscle disease Widespread surface Remissions With steroids None Complications Rare Esophagitis, herniation Findings at esophagoscopy Normal Esophageal ulceration X-ray Loss of peristalsis Loss of peristalsis Motility Decreased Decreased Site of maximum involvement Upper one-third Lower two-thirds. in the esophagus

44 110. Cancer of the respiratory system (listed in decreasing order of frequency):

a. Lung.

b. Larynx.

c. Oral cavity.

d. Pharynx.

e. Tongue.

f. Lip.

111. Chylous leak.

a. < 150 mL/day: apply pressure dressing.

b. > 150 mL/day: explore neck and ligate duct.

112. Esophagus.

A. Tumors.

1. The incidence of carcinoma of the esophagus is increased in patients with:

a. Achalasia.

b. Oculopharyngeal syndrome.

c. Caustic burns.

d. Plummer-Vinson syndrome.

e. Pernicious anaemia.

2. Leiomyoma of the esophagus:

a. Most common benign tumor of the esophagus.

b. Involves the thoracic esophagus.

c. Causes smooth compression of the esophageal lumen on barium swallow.

B. Physiology.

Esophageal pressures:

45 a. 5-10 mm Hg: normal resting pressure of lower esophageal sphincter.

b. 40-60 mm Hg: characteristic of achalasia.

c. 10 mm Hg: compatible with scleroderma or gastro-esophageal reflux.

C. Congenital esophageal stenosis:

1. Most commonly occurs betweent the middle and distal one-third of the esophagus.

2. Treatment is by repeated dilatations.

113. The advantages of surgical resection followed by radiation:

a. Without prior irradiation a frozen section, when obtained, is more reliable.

b. Better wound healing.

The disadvantages:

a. An operated field has decreased blood supply and consequently, poor oxygenation. This condition renders the tumor less radiosensitive.

b. Since there is poorer blood supply, the patient is more susceptible to radionecrosis.

The advantages of preoperative radiation:

a. Since an unoperated field is better vascularized, the tumor is more radiosensitive.

b. Preoperative radiation does not convert an inoperable lesion into an operable one. However, it does help to sterilized submucosal inapparent pseudopod involvement, making the planned margin of resection a safer one.

The disadvantages:

a. Unreliable frozen section.

b. Decreased healing potential.

114. The most commonly encountered malignancy in children is malignant lymphoma. A proper workup should include a histologic diagnosis, limits of the primary lesion, chest PA and lateral x-rays, IVP, and bone marrow study. The overal prognosis is about 30%. Lymphoma can be staged as follows:

Stage I: localized.

Stage II: limited to above the diaphragm without systemic symptoms.

46 Stage III: diffuse disease.

115. Seasonal allergies:

Early spring: trees, pollens.

Late spring: grasses.

Fall: ragweed.

Winter: dust, molds.

116. Cytotoxic allergy testing:

a. Highly sensitive.

b. Employs patient's serum and mixes it with the antigen to be tested.

c. Usually used to test for food allergy.

d. Should be done if skin testing is equivocal.

e. In vitro test, therefore no possibility of anaphylaxis.

f. Reactions are noted even if the antigen has been avoided for a long period.

g. Time consuming.

117. There are two types of asthma:

a. Intrinsic, which usually manifests itself after age 30. It is nonseasonal. It is correlated with infection.

b. Extrinsic, which manifests itself before age 30. It is seasonal.

118. Autocoids.

A. Histamine.

1. Histamine is found in mast cells, platelets, leukocytes, and the parietal cell region of the stomach.

2. It:

a. Contracts smooth muscles.

b. Increases dilatation and permeability of capillaries and venules.

47 c. Dilates arterioles amd venules via a direct action on the musculature.

d. Contracts larger vessels.

e. Stimulates exocrine glands.

f. Increases gastric secretion.

3. Antihistamine (i.e. Benadryl) is not effective against unreleased histamine.

B. Serotonin:

1. Serotonin is found in platelets, cerebral tissues, and the mucosa of the gastrointestinal tract. It is not found in the mast cells in man.

2. It increases capillary permeability.

3. It contracts smooth muscles.

C. Kinins.

These are active polypeptides in blood during certain hypersensitivity reactions.

1. Kallidin I (bradykinin) is found in plasma and increases capillary permeability, causes smooth muscle contraction and vasodilatation. It is formed by the action of enzymes on plasma globulin.

2. Kallidin II is a decapeptide. It has similar properties to Kallidin I, but is formed by different enzymes. The enzyme may be kallikrein.

D. Prostaglandins:

1. Produced by nearly all body tissues.

2. Thousands of analogs (i.e. PGEs, PGFs, PGGs, PGHs, etc).

3. Actions:

a. Potent vasodilators.

b. Increase cardiac output.

c. Regulate platelet aggregation.

d. PGFs contract bronchial and tracheal muscles while PGEs cause relaxation of these muscles.

e. Promote diuresis.

48 f. May stimulate or depress the CNS.

g. Cause the release of ACTH, LH, and thyrotropin (may abort early pregnancies).

h. Appear to amplify pain by sensitizing nerve endings.

4. Mechanism of action is by stimulating cAMP or cGMP production.

119. Cystic fibrosis:

a. Hereditary disease of children and young adults.

b. Generalized dysfunction of the exocrine glands.

c. Features:

1) Chronic obstructive pulmonary disease.

2) Pancreatic insufficiency.

3) High sweat electrolyte levels.

4) Cirrhosis of the liver.

5) Nasal polyps.

d. Diagnosis:

1) Sweat chloride values of greater than 60 mEq/L are considered diagnostic.

120. Innominate artery compression syndrome:

a. Stridor.

b. Recurrent bronchopneumonia.

c. Projectile vomiting with fast feeding

121. Inherited coagulopathies: evaluation and treatment.

A. History: A complete medical history should be taken stressing the following points:

a. Prior surgical procedures: If the patient has undergone a prior surgical procedure without significant hemorrhage, this is often the best indication of normal hemostatic function. More attention should be given to prolonged bleeding requiring transfusions following minor procedures.

49 2. Medications and toxins: One should ascertain whether the patient is taking any medication particularly heparin, warfarin (Coumadin), acetylsalicylic acid, etc, and exposure to toxins at work or at home.

3. Family history of bleeding: This is of particular importance in congenital defects although a small percentage of defects have no positive family history of bleeding.

4. Spontaneous hemorrhage.

5. Prolonged bleeding with minor trauma.

B. Physical examination: A complete physical examination with particular attention to:

1. Purpuras.

2. Hemarthroses.

3. Hepatomegaly.

4. Splenomegaly.

C. Laboratory studies: Table 37-1 is a synopsis of laboratory values usually found in the various coagulation defects.

As a routine for patient undergoing surgical procedures the following tests may be performed. The test f is not used as a screening test.

a. Hemoglobin, hematocrit to rule out anemia from unsuspected bleeding or chronic disease.

b. White blood count with differential to rule out leukemia, infectious diseases, etc.

c. Partial thromboplastin time (PTT) tests for all the coagulation factors except IV, VII, and XII. Normal value is 30-45 seconds (definitely abnormal if over 50 seconds). Consists of adding commercially prepared partial thromboplastin to the patient's plasma in the presence of calcium.

d. Prothrombin time (pro time) tests for Factors II, VII, IX, and X. Consists of adding whole thromboplastin to the patient's plasma in the presence of calcium.

e. Platelet count normal value 100,000/450,000/mm3 depending on method. Bleeding problems usually do not occur unless the platelet count is below 50,000-60,000/mm3.

The PTT and the prothrombin time will detect over 90% of the coagulation defects. Combined with the other tests and a careful history and physical examination, defects in hemostasis should be detected with only rare exceptions.

50 f. Test for specific factors:

A definitive diagnosis for each of the factor deficiencies can be made by assaying for each factor. These tests are particularly helpful when Yable 37-1 fails to give the diagnosis, i.e. fails to differentiate between deficiency in Factor XI and that of XII. Factor assays are extremely specialized and are beyond the scope of this book.

Table 37-1. Laboratory Values in Coagulation Defects

Platelets Bleeding time PTT Pro Time Thrombin Time

I N IorN I I I II N N I I N VNN IIN VII N N N I N VIII N N I N N IX N N I N N XNN IIN XI N N I I N XII N N I N N XIII N N N N N Willebrand N I I N N

D. Treatment

Whan a deficiency is detected using the preceding screening tests or when there is a strong suggestion of hemostatic abnormalities from the history and/or physical examination, a hematologist should be consulted for the management of the patient. Before any treatment is instituted, blood should be drawn for laboratory studies. In the rare instance when the patient is hemorrhaging due to an unsuspected disorder the following guidelines may be used:

1. Minor bleeding:

a. Tamponade.

b. Ice packs.

c. Topical thrombin.

d. Synthetic vasopressin will transiently increase Factor VIII levels in patients with measurable activity.

2. Major bleeding:

a. All of above if feasible.

b. Concentrates of specific factors if diagnosis is known (i.e. Factor VIII or Factor IX deficiencies).

51 c. Cryoprecipitates.

d. Fresh-frozen plasma (contains all factors but no platelets).

e. Fresh whole blood (used only when blood volume needs to be restored).

122. A total of 1056 patients, 90% of whom received greater than 1000 R, 25 or more years ago were scanned - 174 scans were abnormal. Sixty carcinomas were found - 35% of cold nodules in this group are malignant (Favus, M. J.: Thyroid disease after irradiation of neck. N Engl J Med 294:1020, 1976).

Hemaniomas: 96% present by 6 months of age. Natural history of capillary type: slow growth --> rapid expansion --> involution --> regression. If rapidly growing, 300 R may be given. Cavernous and port-wine type tend to be more permanent. Port-wine skin has been treated with argon laser.

Cystic hygroma: abnormal growth of jugular lymphatics:

a. Tends to surround vessels and nerves.

b. Do not regress - may enlarge with URI.

c. Recurrence uncommon postexcision.

123. Facial paralysis: be able to present both sides of the issue.

a. May - Surgical Rounds 1979.

In poor prognostic group (low MST, low tears, or low saliva).

Pts Good % Improv Cx

Total decompression 7 7 100 Dryeye 100% Vertical/horizontal decompression 39 28 70 No Rx 20 7 35 Steroids 31 3 10

b. Adour Laryngoscope, 1978, p. 787.

241 Bell's palsy (unselected). All Pts Total paralysis

No treatment 63% 40% Prednisone 90% 79%

52 124. Congenital nasal masses

Dermoid.

a. Contents: sweat glands, hair, skin.

b. Site: midline (may have opening toi skin), 45% go deep to nasal bones. One-third of these to cribriform.

c. Dx: Examination.

d. Rx: External (may require "open sky" if deep to nasal bones).

Glioma.

a. Content: neural tissue.

b. Site: usually off midline. 15% retain fibrous dural attachment.

Dx: Examination.

Rx: Most removable extracranial.

Encephalocele.

a. Contents: Neural tissue with CSF.

b. Site: In or out of nose. Associated with large bony defects.

c. Dx: Positive Furstenburg's sign. Do not aspirate. Metrizamide scan.

d. Intracranial repair necessary if through cribriform.

125. Davis and Fazekas, In: Controversies in Otolaryngology, J. B. Snow (ed). Radiation Rx for mucoepidermoid of parotid.

a. An irradiation dose of 5000 R given after superficial parotidectomy for T1 lesion decreased recurrence from 50% to 10%.

b. A dose of 6500-7500 R increased local control in patients with tumor left behind at surgery to 70-80%.

126. Doxorubicin (Adriamycin) is the most successful drug so far for parotid malignancies. Lung metastases are most responsive.

127. Mactericidal antibiotics include: penicillins, cephalosporins, aminoglycosides, vancomycin, TMP-SMX.

53 128. Lesser known antibiotic side effects:

a. Carbenicilline: bleeding secondary to platelet inhibition hypokalemia.

b. Aminoglycosides: competitive neuromuscular blockade.

c. Polymixins: noncompetitive neuromuscular blockade.

d. Clindamycin (or any antibiotic): enterocolitis due to C. difficile (Rx for this is vancomycin).

e. Penicillin: interstitial nephritis.

129. Streptococcus: A disease of infants characterized by rhinitis, excoriation at anterior nares, and cervical adenopathy. Rx: penicillin.

130. Bacteriology of chronic sinusitis:

a. Anaerobes 60-80%.

b. Staph. aureus 10-17%.

c. H. influenzae 10%.

d. Rx: Penicillinase resistant penicillin.

Bacteriology of acute sinusitis:

a. Strep. pneumoniaew 43%.

b. H. influenzae 31%.

c. Rx: ampicillin, cefaclor, or erythromycin-sulfa.

d. Deep neck infections are all anaerobic, except for parotid space which is usually staphylococcal. Rx: penicillinase resistant penicillin.

131. Factors to decrease wound infection in head and neck surgery:

a. Becker study: cefazolin decreased infection rate from 84% to 32%.

b. Rice: povidone-iodine irrigation decreased infection from 38% to 2%.

c. Panje: closed-wound suction decreased infection from 6% to 1-2%.

132. H. influenza may be a pathogen in facial (particularly periorbital) cellulitis in children and can be recovered from the nares.

54 133. Chloramphenicol is the drug of choice for serious infections due to H. influenzae:

a. There are strains resistant to ampicillin.

b. Cefmandole may not cure meningitis, which is associated with 10% of facial and buccal H. influenzae cellulitides.

134. Nasal cultures do not correlate with sinus cultures in acute sinusitis.

135. Tonsillectomy mortality:

a. Alexander study (Baltimore, 1953-1964): 1.03 deaths/10,000 patients; of 17 deaths seven were caused by hypoventilation, four by aspiration, and four by hemorrhage.

136. Natural history of peritonsillitis (Fried, Arch Otol 107). Of 57 patients after I and D, only one recurred; 41 patients had one or no sore throats in a year.

137. Mucormycosis (Blitzer, Laryngoscope, 90:635):

a. 170 cases; survival 75%. If diabetic, survival 60% with other illness 20%.

b. Rx: surgical debridement, amphotericin B.

c. Poor prognostic signs: nasal deformity, facial necrosis, hemiplegia.

d. Nonprognostic signs: cranial nerve or ocular signs.

38. Myringotomy and PE tubes are the most frequently performed operations in the USA. Recent literature on otitis media (OM) includes:

a. Epidemiology:

1) Teel, D. W. Ann Otol Rhinol Laryngol suppl 68:

a) Risk factors for recurrent otitis include white race, male sex, allergy, family history for OM.

b) Effusions persist after acute OM. 40% still present at 1 months, 20% at 2 months.

2) Virolainen, Ann Otol Rhinol Laryngol suppl 68:

a) Of 708 year old school children, 8% have serous OM at any time.

b) Risk factors were: history of acute OM; many URIs.

c) No correlation of SOM and allergy in this study of 1200 children.

3) Fiella, Ann Otol Rhinol Laryngol suppl 68:

55 a) Studied 938 healthy children 3 years old.

b) 10% had type B tymp. 70-80% resolve within 6 months (30-40% in 1 month).

b. Bacteriology:

1) Ruokinen, Ann Otol Rhinol Laryngol 88: Adenoids and otitis media.

a) Children with ear problems grew significantly more viruses and H. influenzae from adenoid tissue than did children with adenotonsillitis and no ear problems.

2) Schwartz, JAMA, p. 1270, May 1979:

a) Nasopharyngeal culture predicted middle ear pathogens in 72%.

3) Therapy:

a) Thomsen, J. Ann Otol Rhinol Laryngol suppl 68: Penicillin vs. placebo in acute OM - no difference in response. At 3 months, 25% of both groups had effusions.

b) O'Shea, J. Ann Otol Rhinol Laryngol Suppl 68: Antihistamine/pseudoephedrine vs. placebo - no effect on treatment of serous OM.

c) Cantekin, Bluestone: Ann Otol Rhinol Laryngol Suppl 68: Decongestant improve eustachian tube function in children with URI. No clinical effects reported on, however.

d) Schwartz, Ann Otol Rhinol Laryngol Suppl 68: Prednisone (1 week) successfully cleared serous OM in double-blind crossover study of persistent (>3 weeks-old) effusions. All received sulfisoxazole.

e) Draf, Ann Otol Rhinol Laryngol Suppl 68: PE tubes - 84.8% had normalized hearing; 76.9% required tubes only once; draining ears complicated first surgery in 12%.

f) Gates, Ann Otol Rhinol Laryngol Suppl 68: 15% of effusions are cleared by general anesthesia induction, unrelated to presence or absence of N2O (probably related to positive pressure mask induction).

139. Recent literature on hearing:

a. Goodhill, V. Ann Otol 82, 1973: Fifteen patients with sudden hearing loss explored. Of patients with fistula, only those operated on before 1 month had any improvement. These patients might have gotten better on their own at that early stage.

b. Paparella, Ann Otol Rhinol Laryngol Suppl 68: Bone conduction thresholds decrease with time in chronic OM. Macromolecules can pass into perilymph with the onset of OM.

c. Reiter, Arch Otol 106: Hearing in rheumatoid arthritis S/N loss in 50% (13% of controls). Conductive loss in 13% (0% of controls).

56 d. Wilson, Arch Otol 106:

1) Steroids in sudden hearing loss.

2) Double blind study.

3) All patients with mild loss recovered.

4) Steroids had no effect on dismal prognosis of severe loss.

5) Steroids seemed effective in moderate losses:

a) 78% recovered S/N.

b) 38% recovery in placebo group.

e. Mattox, Simmons, Ann Otol, p. 463, 1977: Natural history of sudden hearing loss; 65% recover to functional hearing regardless of Rx. Bad prognosis signs include down-sloping audio above 4000 Hx, vertigo, high sed. ratge, poor discrimination, late presentation.

140. Surgical treatment of Ménière's disease

a. Arenberg, L. Arch Otol 103:589, 1977.

1) Vertigo relief from surgery 70-90%.

2) Hearing improvement 0-70%.

3) States that early surgery works best if glycerol test is positive.

4) Advises vestibular nerve section if glycerol test is negative.

b)Austin, Arch Otol 106, Jul 1980.

1) Endolymphatic sac surgery "successful" in 22/26 patients in whom vestibular aqueduct was tomographically patent and in only 1/13 patients with nondemonstrable aqueducts.

c. Thomsen, Arch Otol 107:271, 1981.

1) Placebo effect of surgery in Ménière's disease: 1 year follow-up 70-80% improved whether they underwent simple mastoid or sac surgery.

2) Vertigo and hearing results slightly better in sac group (p<0.05).

141. Results of stapes surgery in a private practice. P. J. Doyle, J Otolaryngol 1:5 1980.

57 a. Eighty-six patients: 75 using fat-wire prosthesis.

1) Better hearing 73%.

2) Improved subjectively 63%.

3) Dizzy from 2 weeks to 3 months 53%.

4) Hearing worse 10%.

142. Revision stapes surgery. J. Crabtree, Laryngoscope 90:224, Feb 1980.

a. Thirty-five revisions:

1) Twenty-six for conductive loss - 15 were improved, two were worse.

2) Nine for sensorineural loss - one was improved, five were worse.

143. Immunodeficiency in Pediatric ENT. Kimmelman, C., Ann J Otol Fall 1979.

a. Hypogammaglobulinemia accounts for 50% - presents with pneumonia.

b. IgA deficiency accounts for 33% - presents with URIs.

c. Chemotactic defects account for 13% and present with pneumonia.

144. Relapsing polychondritis. Damiani, J. Laryngoscopy p. 929, 1979.

a. Current therapy includes dapsone, immunosuppressives, and steroids.

145. Face-lift pearls:

a. Sun exposure is the most significant factor in premature aging.

b. Diseases of premature aging (all autosomal recessive) include:

1) Cutis laxa, associated with hernias, emphysema, aneurysms - repeated lifting may help.

2) Progeria, associated growth retardation and early atherosclerosis - lifting is not recommended.

3) Werner's syndrome, associated with high-pitched voice, diabetes, osteoporosis - lifting not recommended.

c. Most authorities recommend dissection superficial to platysma, but beneath galea temporally to avoid hair follicles.

58 d. Complications: hematoma 1-8% usually within 24 hours, presents with pain - more common in males; hair loss, skin slough, nerve loss, salivary cysts (which usually respond to aspiration and pressure).

146. Chemical face peeling.

Materials: phenol, crotonil, soap, water.

Indications: fine wrinkles, erasure of dermabrasion demarcation.

Precautions:

a. Dark-skinned individuals may lose pigmentation.

b. Peel regions rich in adnexal structures.

c. If for pigmentation, do superficial peel (no tape).

Phenol toxicity:

a. Cardiac arrhythmias.

b. Cental depression, decreased blood pressure, headache, nausea.

Complications:

a. Bleaching.

b. Blotchy hyperpigmentation - best avoided by cleansing.

c. Peroral scarring - avoid face-lift at same sitting.

d. Prominent skin pores - avoid deep peel in young patients treated for pigemntation.

Healing timetable for chemical face peel or dermabrasion:

5 days: epidermis regenerates

7 days: epidermis loosely attached to dermis

2 weeks: new collagen deposited, fills out dermis giving youtful appearance.

1 month: pigmentation begins to return in spots; milia may appear.

6 months: epidermis normal thickness.

10 months: dermis normalizes.

59 147. Nasal polyps in children:

a. Antral choanal in 33%, few of whom are allergic, almost all cured with Caldwell- Luc procedure.

b. Bilateral in 47%, two-thirds with cystic fibrosis, one-third were allergic.

148. Polypectomy does not affect the course of asthma in Samter's syndrome (aspirine hypersensitivity). Brown. Arch Otol 105, July 1979.

149. Multiple malignancies in head and neck cancer. Weichert, Laryngoscope 89:933, July 1979.

a. Incidence of second primaries 6.5%; synchronous in one-third of these.

150. Dermatofibroma dimples when squeezed, melanoma does not.

Facts to Know

When preparing for an oral examination, it is helpful for the candidate to be familiar with the history, physical findings, radiologic findings, and pathologic findings of a few common disease entities. It is also appropriate for him to know prognosis, and certain statistics discussed in the recent literature. Some of the clinical disease entities are:

1. A lump in the neck: Is this infectious, cystic, or a hard tumor? Possible tuberculosis, fungal diseases, cat scratch fever, lymphoma, thyroid disease may be implicated. Is a barium swallow necessary? Cervical spine films? Is this a mass with an unknown primary malignancy (nasopharynx, base of tongue, and pyriform sinus)?

2. Evaluating a child with airway problem: Is it congenital? Is it vascular? Is it pharyngeal or laryngeal? Is it secondary to a foreign body?

3. The etiologies for a nasal septum perforation.

4. Paralysis of the vocal cord: a workup may include complete blood count, urinalysis, chest and cervical spine x-rays, barium swallow, lumbar puncture, glucose tolerance test, ESR, neurologic consultation, all x-rays, etc. What is Ortner's syndrome? What does the ECG show? Is there any thyroid disease? Does sarcoidosis enter the list of differnetial diagnoses?

5. Massive facial fracture: emergency room management and definitive surgical care.

6. Sinusitis: acute sinusitis as well as chronic sinusitis, able to read x-rays adequately, able to treat the acute problems as well as the long-term problems.

7. Tinnitus: character of the tinnitus, is it pulsatile? What brought it on? Duration, hearing loss, vertigo, complete neurologic and otolaryngologic examination. Do acoustic trauma, glomus tumor, acoustic neurinoma enter into the list of differential diagnoses? Be prepared to order the necessary tests to further evaluate a patient with tinnitus; be prepared

60 to justify ordering the particular test or tests. Also be prepared to discuss the technique of how some of the tests are done and the interpretation of some of the tests, for example, ABLB, Bekesy, BSER.

8. Vertigo: The history and character of the vertigo are very important. Definition of vertigo, dizziness, lightheadedness, etc, is important. Be prepared to workup the patient with dizziness not only from an otologic standpoint, but perhaps from a cardiovascular, endocrine, allergic, and neurologic standpoint. Here again, be discriminative in what tests you order and be able to describe the technique as well as the results.

9. Chronic otitis media: Immediate management as well as long term management.

10. Sudden hearing loss: Be familiar with the current concepts and literature on the etiology and management of this disease entity.

11. Malignancies of the various otolaryngologic and anatomic sites.

12. Management of a conductive hearing loss not necessarily secondary to otosclerosis - complications of middle ear surgery.

13. Facial nerve palsies of various etiologies: management, different electrical testings.

14. Nasal obstruction in children: choanal polyp, allergic polyps, enlarged adenoid, angiofibroma, fibroma, deviated septum, allergy, choanal atresia, foreign body, tumor, etc.

15. Prepare to discuss progressive hearing loss and vertigo in children and adults, Ménière's disease, acoustic neurinoma, meningioma, congenital syphilis, suppurative labyrinthitis, cholesteatoma, ototoxicity, Cogan's syndrome, otosclerosis, eosinophilic granuloma, perilymphatic fistula, vascular, viral, and functional hearing loss. What are the syndromes that can give hearing loss and vertigo? (See Chap. 9).

16. Prepare to discuss metabolic and electrolyte disorders in postoperative patients. The following points may be used to help in your preparation:

a. The daily fluid requirement is 2200 mL/24 hr.

b. The daily output of fluid is about 700 mL through resopiration, 1200 mL in the urine, 100 mL through perspiration if the patient has no fever, and 200 mL in the feces.

c. The daily caloric need ranges from 1800 calories to 3000 calories depending on the metabolic rate.

d. During surgery, when the skin incision is made:

1) Catechols, growth hormones, and cortisol levels are increased leading to an increase in serum glucose, gluconeogenesis, glucagon level, and a decrease in insulin receptor sites.

2) There is an increase in ADH leading to decreased urinary output.

61 e. Symptoms of water intoxication are lethargy, seizuree activities and coma. Serum sodium in the range of 115-120 mEq/L. Water intoxication can lead to congestive heart failure, decreased glomerular flow rate, and renal failure.

f. SIADH (syndrome of inappropriate ADH) can be caused by chlorpropamide (Diabinese), clofibrate (Atromid), vincristine, cyclophosphamide (Cytoxan), meperidine (Demerol), and morphine sulfate. The findings are low serum, increased urinary sodium, and increased urine osmolality (greater than 300 mOsm).

g. Metabolic acidosis can be caused by lactic acidosis which can be secondary to excessive ethanolic intake, obstructive pulmonary disease, sepsis, DBI, and acetazolamide (Diamox). Sepsis is a common cause of lactic acidosis in postoperative patients.

h. Metabolic alkalosis can be caused by vomiting, nasogastric tube suction, decreased extracellular fluid volume, decreased chloride and potassium, increased aldosterone levels, and by diuretics. One of the treatments is replacement of chloride.

i. Hyperosmolar coma (i.e. greater than 340 mOsm/L; the normal value is 285-290 mOsm/L) is a condition that can be caused by phenytoin (Dilantin), steroids, thiazide diuretics, myocardial infarction, and stroke. The serum sodium, BUN and blood sugar are elevated. In spite of elevated serum glucose, there is no ketoacidosis.

j. Normal serum values:

Na = 140

K=4

Cl = 95-105

Bicarbonate = 28

Normal arterial blood gases:

PO2 = 95-100

pCO2 =40

pH = 7.4

Oxygen saturation = 97-100%

k. Weight loss, decreased serum albumin, and decreased total iron binding capacity are indications of malnutrition in a postoperative patient. A decrease in caloric intake leads to ketosis which in turn leads to decreased urinary excretion of uric acid which can cause gout symptoms. Remember that 1000 mL of 5% dextrose and water IV solution has only 200 calories.

62 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 38: Nutritional Assessment and Support

History

The nutritional support of patients who have been stressed by disease has been the topic of research for years. Dudrick in 1968 showed that animals could be nutritionally supported by venous access for long periods and maintain a positive growth curve. The method was then applied to patients who had lost gastrointestinal functions with similar positive nutritional responses. This led to evidence which showed that surgical mortality was linked to malnutrition which was measured by body weight loss and protein depletion. The thrust of nutritional science in the past 10 years has been to develop a method and understanding that will reverse the malnourished state or prevent its occurrence.

Nutritional Assessment

Although the physical examination and history are the hallmarks of any clinical evaluation, they can be misleading regarding the true nutritional status of a given patient. To pinpoint the nutritional problems more accurately, Blackburn developed a nutritional profile to measure fat stores or somatic and visceral protein. Different parameters can be measured to quantify the deficits of the malnourished patient.

Anthropometric Measurements

1. Height and weight are the most simple and fundamental measurements. The current height and weight are compared to established norms. If the weight loss has been greater than 10% in the past 6 months the change is considered severe.

2. The body fat compartment is assessed by measurement of the triceps skin fold.

3. The midarm circumference measures both fat and somatic protein. The lean body mass or somatic protein can be estimated by using the triceps skin fold and midarm circumference data.

Laboratory Measurements

1. The creatinine: Height index was developed by Bristrian. As a sensitive measure of somatic protein, creatinine, broken down from muscle, is excreted in the urine. Reduced creatinine excretion is indicative of muscle loss and protein malnutrition. The expected creatinine excretion is dependent on the height of the patient.

2. Visceral proteins are measured in the form of serum albumin and transferrin. Transferrin is an acute phase protein and reflects early changes in protein nutrition. Its measurement is used to reflect early evidence of protein malnutrition as well as the earliest evidence of its reversal.

1 3. The immune response, the hallmark of the body's means to repond to invading substances, is measured by the lymphocyte count and the reaction to intradermal challenge antigens, i.e. mumps, candida, and purified protein derivative.

Energy Requirements for Adequate Nutrition

The basal energy requirements for in-hospital patients are similar to the requirements in those persons without medical needs. That is, the total energy needs are determined by the normal basal energy expenditure in addition to the energy needs related to the underlying injury or disease.

In the basal state, energy is required for the synthesis of structure, the mechanical work of the vital organs, and the chemical work of cells. The amount of physiologic activity is the determining factor in calculating the energy needs of a particular hospitalized patient. The basal metabolic rate is presumed to be constant for persons of the same age, sex, and shape. Various types of stress - fever, peritonitis, and burn shock - demand varying levels of energy expenditure above the basal requirements.

In the preoperative or preinjury state, the caloric requirement is determined by the basal metabolic rate plus the energy needed in such activities as walking, running, and working. Postoperative and postinjury patients need the same number of calories for basal metabolism in addition to calories to supply the needed energy for healing, sepsir, or fever. The ratio of carbohydrate, protein, and fat to supply the caloric requirements, as calculated, vary somewhat depending on the patient's baseline biochemical functions and nutritional state.

Data are lacking to determine the exact number of calories supplied intravenously to attain positive nitrogen balance. Thus Kinney suggests that the intravenous caloric need should be 50% above the calculated clinical needs. The ratio of nitrogen (derived from protein) to total calories determines the adequate utilization of the ingested protein. The ratio of 120-180 cal/g of nitrogen is used when calculating carbohydrate and protein needs for parenteral nutrition.

Parenteral Nutrition

Indications

The three main indications for parenteral nutrition are:

1. Severe protein malnutrition with loss of adequate gastrointestinal mucosal function, thus reducing digestive and absorption function of the gastrointestinal tract.

2. Primary disease of the gastrointestinal tract obviating its use either because of lack of access or need for bowel rest.

3. Altered mental state with inability to swallow or loss of gag reflex and the possibility of aspiration.

2 Route

The route of parenteral nutritional support may be peripheral or central.

Peripheral Parenteral Nutrition

This is indicated for the patient who may require long-term parenteral support, but this decision is pending further clarification of the clinical situation. While the decision as to ability or inability to utilize the enteral route is pending, and to prevent further nutritional deficits, peripheral nutritional support can be instituted. The preferred method to accomplish the task of reducing the catabolic state is to give 5-10% dextrose and 3.5% amino acids for a total of approximately 2000 mL/day with 500 mL or more of intralipid to adjust to the total caloric need.

The protein-sparing method, using the peripheral route with amino acids only, can be considered. Protein sparing implies the peripheral intravenous administration of amino acid fluid. Previous use of 5% dextrose provides an inadequate number of calories to block protein catabolism for caloric needs. In addition, use of dextrose leads to an increase release of insulin with its antilipolytic effect. This antilipolytic effect inhibits stored body fat breakdown for calories and therefore more protein is catabolized for the needed calories.

Amino acid solutions without glucose in a catabolic patient can reduce the negative nitrogen balance. The use of branch-chain amino acids may inhibit the flux of amino acids from muscle and thus effectively reduce muscle protein breakdown. However, it must be noted that others have shown that glucose does not impair nitrogen sparing because hyperinsulinemia, which occurs following the use of glucose with an amino acid mixture, is associated with a fall in the amino acid blood pool, and stimulates muscle uptake of branch- chain amino acids for protein synthesis.

Central Parenteral Nutrition

The central parenteral route is indicated when the enteral route is unavailable, the proposed support is greater than 7-10 days, and large caloric requirements are needed to reverse the catabolic state.

Method of Central Parenteral Nutrition

Catheter Placement. Hypertonic solutions require a central high-flow vein for infusion. Superior vena cava infusion via the subclavian vein is the preferred route. The catheter is placed in the subclavian vein after a sterile surgical preparation of the skin of the neck, supraclavicular region, and anterior chest wall. The skin and periosteum overlying the clavicle are infiltrated with local anesthesia. The patient is placed in a Trendelenburg's position and a needle is placed into the subclavian vein which allows for placement of the catheter into the vena cava.

Preparation and Composition of Central Parenteral Solutions. A laminar blood flow hood in the pharmacy is used for preparation of the hypertonic glucose and amino acids solution. The composition of this hypertonic fluid (1800-2400 mOsm) is glucose and protein,

3 as amino acids. Fats are given in tandem as a 10 or 20% fatty acid solution. The glucose is given as 20 or 25% solution which produces 800-1000 cal/L. The infusion of glucose causes a rise in blood sugar and stimulates insulin release. This provides an immediate energy source and in high concentrations provides the calories for total energy needs allowing concomitant amino acid infusion to be used for protein synthesis and efforts to obtain an anabolic state. The amino acids, either centrally or peripherally, are needed to obtain this anabolic state for protein build-up.

Fat metabolism is influenced by the insulin release. The glucose is broken down into carbon fragments which are used for the synthesis of fatty acids. Glycerophosphate, produced from the glucose, binds with fatty acids for the production of triglycerides. The type of intravenous alimentation appropriate for the individual patient depends on the underlying problem, the nutritional state at the time of evaluation, and the length of time needed for intravenous nutritional support. The catabolic patient requires 100-150 cal/g of nitrogen for tissue synthesis. Hypertonic glucose with the addition of 3.5% amino acids provides the necessary calories as well as the nitrogen required for reversal of this catabolic state.

The hyperalimentation mixture also contains multiple electrolytes and minerals. Sodium, chloride, and potassium are essential. Potassium is needed in large quantities because of the protein synthesis. Calcium, phosphate, magnesium, and vitamin K are all needed on a daily basis to maintain adequate cellular function. Trace elements are necessary in conditions where parenteral nutrition is maintained for long periods.

Monitoring Central Parenteral Infusions

Laboratory studies which include liver function tests, electrolytes, measurement of acute phase protein, CBC, prothrombin time, calcium, phosphorus, and magnesium are all necessary before the institution of central parenteral nutrition. This gives a baseline of the nutritional state; these levels also must be followed closely after the institution of therapy to maintain adequate homestasis.

Complications of Central Parenteral Nutrition

The catheter insertion may result in pneumothorax, hemothorax, or injury to the subclavian artery, vein, brachial plexus, phrenic nerve, thoracic duct, or vagus nerve. The catheter may cause sepsis, and this is the most frequent complication of the catheter placement. There are multiple metabolic complications which can occur. In particular, hypertonic glucose loading may produce hypoglycemic shock, and essential fatty acid deficiency can result if lipids are not administered. The imbalance of various mineral levels such as sodium, potassium, calcium, phosphorus, magnesium are common difficulties, and deficiencies of trace elements including zinc, copper, and chromium have been described. Careful metabolic monitoring as previously described is needed to prevent these complications.

Enteral Nutrition

The route of enteral nutrition support is via a nasogastric tube, tube gastrostomy, or tube enterostomy. The nasogastric tube is valuable for its ease of placement. It has many

4 disadvantages, especially in patients with nasopharyngeal disease either in the pre- or postoperative state. The commonly used No. 16 French plastic or rubber tube causes significant reaction along the tissues in which it is in contact. The gastroesophageal junction becomes incompetent because of the tube traversing the gastroesophageal sphincter. This leads to esophageal reflux and esophagitis, but more importantly, reflux and possible aspiration. When the nasogastric route is chosen, and it is the preferred route under certain circumstances, a No. 8 French silastic catheter should be used. This reduces the tissue reaction, sphincter incompetence, and gastric irritation. The placement of a gastrostomy tube or tube jejunostomy is indicated for long-term enteral nutritional support in patients who cannot maintain adequate oral alimentation. The dietary liquid formulas for tube use are many. They vary in their physical and chemical characteristics.

The elemental diet is residue-free and contains protein in the amino acid or hydrolysate form. It is significantly fat free except for essential fatty acids and the carbohydrates are oligosacharides with or without dextrose of sucrose. Its indication for use is in a patient who cannot tolerate residue in the gastrointestinal tract, i.e. gastrointestinal fistulas, short bowel syndrome, or the markedly malnourished with impaired small-bowel mucosal function needed for digestion and absorption of more complex chemical nutritional substances.

The full-liquid commercial diets have varying features that make it possible to tailor them to each clinical situation and patient. These diets can be used orally in the preoperative patient for nutritional supplement or in the pre- or postoperative period when the patient cannot or will not chew or swallow solid foods. Full-liquid commercial diets have varying palatability, but some can easily be orally ingested. With a silastic No. 8 French nasogastric catheter, a gastrostomy, or jejunostomy tube, these commercial full-liquid diets are easily used to provide full or partial nutritional support. The gastrointestinal tract can be used in this fashion to eventually tolerate 2000-3000 mL/day providing 2000-3000 calories of balanced nutrients with daily allowances of vitamins and minerals.

Nutritional assessment and support are the hallmarks of reducing morbidity and mortality in the malnourished patient undergoing surgical treatment. The route of support is determined by the needs of the patient and routes available for delivery. The central parenteral route is available in lieu of the preferred, but at times, inaccessible enteral route.

5 K. J. Lee: Essential Otolaryngology and Head and Neck Surgery (IIIrd Ed)

Chapter 39: Multiple Choice Quiz

Answers are not given so as to offer the reader an opportunity to pursue each topic further. The editor feels that a question taken as an end in itself is of less educational value than when it is used as a "spring-board" to explore the whole subject.

1. Embryologically, melanomas are said to arise from:

A. neurocrest cells

B. ectodermal cells

C. entodermal cells

D. mesodermal cells

E. none of the above.

A. Neurocrest cells. Melanocytes are believed to be derived from the neural crest cells that have migrated peripherally to the integument by the twelfth week of gestation. The melanocyte forms the pigment which is then transmitted to the malpighian cells of the basal layer of the skin.

2. Pseudoepithelial hyperplasia can be caused by:

A. blastomycosis

B. granular cell myoblastoma

C. blastomycosis and granular cell myoblastoma

D. sarcoid

E. none of the above.

B. Granular cell myoblastoma.

Abrikossoff's Tumor (granular cell myoblastoma): Causes pseudoepithelial hyperplasia in the larynx, the site most favored in the larynx being the posterior half of the vocal cord. Three percent of granular cell myoblastoma progresses to malignancy. In order of decreasing frequency of involvement, the granular cell myoblastoma occurs in tongue, skin, breast, subcutaneous tissue, and respiratory tract.

3. The thyroid gland is supplied by:

A. paired superior thyroid arteries

1 B. paired inferior thyroid arteries

C. unpaired thyroidea ima

D. none of the above

E. all of the above.

E. All of the above. The gland is richly supplied with blood by the paired superior and inferior thyroid arteries. The former is a branch of the external carotid artery, and the latter a branch of the thyrocervical trunk of the subclavian artery. In addition, the isthmus in some instances is supplied by the unpaired thyroidea ima, a branch of the aortic arch or the innominate artery. Superior, middle, and inferior thyroid veins drain the blood into the internal jugular and brachiocephalic veins.

4. Reverting to primitive cell type is called:

A. dyskeratosis

B. parakeratosis

C. acanthosis

D. anaplasia

E. metaplasia.

5. Statistics have shown that:

A. 60% of parotid tumors are benign and 50% of the submaxillary tumors are malignant.

B. 50% of parotid and submaxillary tumors are benign.

C. 80% of parotid tumors are benign and 50% of submaxillary tumors are malignant.

D. 80% of parotid and submaxillary tumors are benign.

E. Acinic cell carcinomas of the parotid usually are located in the deep lobe.

6. The most common parotid lesion in children is:

A. mixed tumor

B. lymphangioma and hemangioma

C. lymphoma

2 D. mucoepidermoid carcinoma

E. Warthin's tumor.

B. Lymphangioma and hemangioma.

Hemangioma of the Parotid Gland. It is the most common tumor of the parotid in infancy. Goldman advocates prompt surgical excision as soon as definite growth is recognized, while others suggest waiting until age 5. Nussbaum et al reported cavernous hemangioma of the salivary gland in five adults. Infantile hemangiomas of the salivary gland are usually of the capillary type.

Lymphangioma. Lymphangioma is a congenital, benign, unilocular or multilocular, endothelium-lined, fluid-containing swelling of lymphatic origin. In 80% of the cases, the lesion is located in the neck. This condition is present at birth in 65% of the cases and would have manifested itself by age 2 in 90%. When symptomatic, they should be resected to prevent stridor and dysphagia in the infant. Resection should be performed carefully to spare all the vital structures. Lymphangioma has been said to be the most common tumor of the parotid gland in children.

7. Warthin's tumor of the parotid is most common in:

A. the tail of the parotid in females over 60 years old

B. the tail of the parotid in males over 60 years old

C. the superficial lobe, equally distributed in both sexes

D. the deep lobe in females

E. young adult males.

8. Pleomorphic adenoma of the salivary glands consists of:

A. ductal elements only

B. predominance of lymphocytes

C. epithelial and myoepithelial elements

D. cartilage rest cells

E. none of the above.

9. The half-life of T4 is:

A. 1-2 hours

3 B. 2-3 days

C. 6-7 days

D. 1-2 weeks

E. none of the above.

10. The stylopharyngeus is innervated by:

A. X

B. XI (bulbar root)

C. VII

D. mandibular division of X

E. IX.

11. The most common site of orbital floor fratures is:

A. anteromedial

B. anterolateral

C. posteromedial

D. posterolateral

E. variable.

12. The most common type of zygomatic fracture is:

A. arch fracture without displacement

B. trimalar fracture

C. body fracture without rotation

D. arch fracture with displacement

E. body fracture with rotation.

13. In order of frequencies, which one of the following is correct?

A. Condylar, body, angle, symphysis, alveolar F(x).

4 B. Condylar, ramus, symphysis, coronoid F(x).

C. Body, angle, ramus, symphysis F(x).

D. Symphysis, body, angle, coronoid F(x).

E. Condylar, alveolar, symphysis, body F(x).

A. Condylar, body, angle, symphysis, alveolar F(x). Condyle 36%, body 21%, angle 20%, parasymphyseal 14%, alveolar 3%, ramus 3%, coronoid 2%, symphyseal 1%.

14. In equivocal mandibular fracture, measuring the angle of the mandible is a helpful hint. The angle of a young child between 5-10 years old is approximately:

A. 90°

B. 110°

C. 175°

D. 140°

E. about the same as an edentulous patient.

15. Criteria for supraglottic laryngectomy in a supraglottic lesion include all except the lesion does not:

A. come within 5 cm of the foramen cecum

B. include the anterior commisure

C. involve either arytenoid

D. involve the apex of the pyriform sinus

E. involve the postcricoid area.

16. Sloughing of pedicle flaps usually is due to:

A. tissue edema

B. poor vascular supply

C. constricting dressings

D. radiated receptor site

5 E. infection.

17. Which one of the following has been found to be deficient in patients with juvenile papilloma?

A. Fe

B. Mg

C. Zn

D. Gamma globulin

E. Viral antibody.

18. One type of hemangioma which does not usually regress is:

A. a hemangioma that grows aggressively during the first year of life

B. the cavernous type

C. the capillary type

D. subglottic hemangioma

E. spider hemangioma.

19. The most common type of tracheoesophageal fistula and esophageal atresia is:

A. the upper esophagus is connected with the trachea while the lower segment ends in a blind pouch

B. both upper and lower esophageal segments connect with the trachea

C. neither segment connects with the trachea

D. the upper esophagus ends in a blind pouch, the lower esophagus is connected with the trachea

E. completely variable.

21. Each of the following situations suggests a central lesion EXCEPT:

A. gaze nystagmus

B. Nylen-Aschan type II positional nystagmus

C. symmetrical optokinetic nystagmus

6 D. Nylen-Aschan type I positional nystagmus

E. fixation accentuates nystagmus or fixation fails to suppress nystagmus.

22. The foramen of Luschke:

A. is in the vicinity of the fissure of Santorini

B. transmits the chorda tympani nerve

C. transmits sympathetic fibers

D. transmits parasympathetic fibers

E. transmits both sympathetic and parasympathetic fibers.

23. The most common congenital pulmonary abnormality is found in the:

A. right lower lobe

B. right middle lobe

C. right upper lobe

D. left upper lobe

E. left lower lobe.

24. In a normal adult, which one of the following situations is correct?

A. The carotid body is more sensitive to oxygen tension than to CO2 tension; the respiratory center is more sensitive to CO2 tension than to oxygen tension, the carotid sinus has a regulatory function on blood pressure.

B. The carotid body has a regulatory function on blood pressure, the respiratory center is more sensitive to oxygen tension than to CO2 tension, the carotid sinus is more sensitive to oxygen than to CO2 tension.

C. The carotid body is more sensitive to CO2 tension than to oxygen tension, the respiratory center is more sensitive to CO2 tension than to oxygen tension, the carotid sinus has a regulatory function on blood pressure.

D. The carotid body is more sensitive to oxygen tension than to CO2 tension, the respiratory center is more sensitive to oxygen tension than to CO2 tension, the carotid sinus has a regulatory function on blood pressure.

E. The carotid body is equally sensitive to oxygen tension and CO2 tension while the carotid sinus has a regulatory function on blood pressure.

7 25. Among the local anesthetic agents listed, the most toxic dose for a 70 kg adult is:

A. 100 mL of 0.5% procaine infiltration

B. 20 mL of 2% Xylocaine infiltration

C. 5 mL of 4% cocaine topically

D. 10 mL of 2% tetracaine infiltration

E. 20 mL of 2% Carbocaine infiltration.

26. A 40-year-old white male presents with a midline neck mass. Biopsy reveals a tumor showing calcification and the presence of psammoma bodies histologically. The most likely diagnosis is:

A. calcified tubercle

B. papillary carcinoma of the thyroid

C. medullary carcinoma of the thyroid

D. Hashimoto's thyroiditis

E. thyroid cyst.

B. Papillary carcinoma of the thyroid. Psammoma Bodies: These are found in papillary carcinoma of the thyroid.

27. Medullary carcinoma of the thyroid is believed to:

A. be thyrocalcitonin producing

B. have dense stroma with amyloid deposition and tobe thyrocalcitonin producing

C. have scattered calcifications

D. have psammoma bodies

E. have none of the above.

28. Embryologically, carotid body tumors are believed to arise from:

A. neurocrest cells

B. ectodermal cells

C. entodermal cells

8 D. mesodermal cells

E. epithelial and myoepithelial cells.

29. Doubling the amplitude of vibration would cause a:

A. 10 dB increase in intensity

B. 6 dB increase in intensity

C. 50 dB increase in intensity

D. 27 dB increase in intensity

E. 30 dB increase in intensity.

30. All of the following are equivalents EXCEPT:

A. 0 dB at 1000 Hz

B. 10-16 W/cm2

C. 0.0002 dynes/cm2

D. 0.0002 microbar

E. 10-12 W/cm2.

31. The combination of the tympanic membrane footplate transformer mechanism and the lever mechanism amplifies sound by:

A. 10 dB

B. 50 dB

C. 30 dB

D. 25 dB

E. 15 dB.

32. The area of the footplate is:

A. 3.5 mm2

B.2mm2

C.5mm2

9 D. variable

E.1mm2.

33. The area of the round window is:

A. 3.5 mm2

B.2mm2

C.5mm2

D. variable

E.1mm2.

34. Mikulicz's disease is commonly associated with an increased incidence of:

A. lymphoma

B. macroglobulinemia

C. hypoglobulinemia

D. lymphoma and macroglobulinemia

E. lymphoma and hypoglobulinemia.

35. The most common malignant tumor of the submaxillary gland is:

A. adenocystic carcinoma

B. squamous cell carcinoma

C. mucoepidermoid carcinoma

D. malignant mixed tumor

E. lymphoma

36. Brooke's tumor is:

A. of squamous cell origin

B. of ductal cell origin

C. of basal cell origin

10 D. a cartilaginous tumor

E. highly malignant.

37. A 65-year-old edentulous male suffered a bilateral telescoping subcondylar fracture. This is best treated by:

A. intermaxillary fixation with the help of gunning splints

B. bilateral open reduction with intermaxillary fixation for 6 weeks postoperatively

C. unilateral open reduction with fixation postoperatively for 3 weeks

D. bilateral open reduction and no fixation postoperatively

E. unilateral open reduction with fixation postoperatively for 6 weeks.

38. T3 resin uptake measures:

A. unoccupied protein-binding sites for T4

B. unoccupied protein-binding sites for T3

C. serum T3 level

D. serum rT3 level

E. free T3 level in serum.

39. Components of Graves' disease include:

A. hyperthyroidism

B. diffuse thyroid enlargement

C. infiltrative ophthalmopathy

D. infiltrative dermopathy

E. all of the above.

40. The most common site of accessory salivary gland tumor is the:

A. soft palate

B. hard palate

C. sublingual area

11 D. buccal mucosa

E. posterior pharyngeal wall.

41. The Galen's anastomosis is the anastomosis between the:

A. IX and X nerves in the pharyngeal plexus

B. lesser superficial petrosal nerve and the sympathetic fibers

C. right and left superior laryngeal nerves

D. superior laryngeal nerve and the recurrent laryngeal nerve

E. superior thyroid artery and the inferior thyroid artery.

D. Superior laryngeal nerve and the recurrent laryngeal nerve. Galen's Anastomosis: An anastomosis between the superior laryngeal nerve and the recurrent laryngeal nerve.

42. Among the anatomic sites listed, hereditary lipoid proteinosis most commonly affects:

A. tongue

B. thyroid

C. larynx

D. mastoid air cells

E. nose.

43. Normal sweat chloride is:

A. between 50 mEq/L and 100 mEq/L

B. 120 mEq/L

C. less than 50 mEq/L

D. 75 mEq/L

E. 150 mEq/L.

44. All of the following are considered adequate urine output for a patient EXCEPT:

A. 1200 mL/24 hr

12 B. 10 drops/min

C. 30 mL/hr

D. 30 drops/min

E. none of the above.

45. Leukoplakia has all of the following EXCEPT:

A. parakeratosis

B. hyperkeratosis

C. desmoplasia

D. dyskeratosis

E. a whitish color.

46. A 50-year-old black female presents with facial paralysis and a parotid mass. Biopsy of her mediastinum would reveal a mass which would have one of the following histologic characteristics:

A. Schaumann's bodies

B. Mikulicz's cells

C. Verocay bodies

D. Warthin-Finkelday cells

E. Phylasiferous cells.

47. A 35-year-old white female presents with episodic vertigo, unilateral severe sensorineural hearing loss, unilateral tinnitus. Further audiometric examination revealed a high SISI score and a type II Bekesy's. A Silverstein's labyrinthotomy would reveal a fluid containing all of the following EXCEPT:

A. succinate dehydrogenase

B. malic dehydrogenase

C. diaphorases

D. potassium concentration of 150 mEq/L

E. sodium concentration of 150 mEq/L.

13 48. A 43-year-old mother gave birth to a 9-lb girl. The child is mentally retarded and of short stature. At 15 years of age she still has not shown signs of frontal sinus development. This syndrome is often associated with:

A. conductive hearing loss

B. abnormal E chromosomes

C. fishlike mouth

D. acute leukemia

E. macroglobulinemia.

49. A 12-year-old boy has recurrent pneumonitis, associated with eosinophilia. A question of parasitic involvement was raised. This has been referred to as:

A. Adie's syndrome

B. Loeffler's syndrome

C. Kartagener's syndrome

D. Wallenberg's syndrome

E. right middle lobe syndrome.

B. Loeffler's syndrome.

Adie's Syndrome. Adie's syndrome is characterized by decreased pupillary reaction and deep tendon reflex. The etiology is unknown.

Loeffler's Syndrome. This consists of pneumonitis characterized by eosinophiles in the tissues. This is possibly of parasitic etiology.

Kartagener's Syndrome. The symptoms are complete situs inversus associated with chronic sinusitis and bronchiectasis. This also is called Kartagener's triad.

Wallenberg's Syndrome. Also called syndrome of the posterior inferior cerebellar artery thrombosis or lateral meduallary syndrome, this syndrome is due to thrombosis of the posteroinferior cerebellar artery giving rise to ischemia of the brain stem (lateral medullary region). Symptoms include vertigo, nystagmus, nausea, vomiting, Horner's syndrome, dysphagia, dysphonia, hypotonia, asthenia, ataxia, falling to the side of the lesion and loss of pain and temperature sense on the ipsilateral face and contralateral side below the neck.

Middle Lobe Syndrome. This is a chronic atelectatic process with fibrosis in one or both segments of the middle lobe. It is usually secondary to obstruction of the middle lobe

14 bronchus by hilar adenopathy. The hilar adenopthy my be transient but the bronchiectasis that resulted persists. Treatment is by surgical resection.

50. A 36-year-old male has a long history of chronic suppurative otitis media. Two days ago he developed pain over the mastoid region with "picket fence" spiking fever. He is lethargic and toxic. Which of the signs would most likely be elicited?

A. Kernig's sign

B. Brudzinski's sign

C. Hennebert's sign

D. Wartenberg's sign

E. Griesinger's sign.

51. Subclavian steal syndrome is associated with all of the following EXCEPT:

A. nuchal rigidity

B. intermittent vertigo

C. blurred vision

D. occipital headache

E. pain in the upper extremity.

52. A 50-year-old French Canadian woman presents with ptosis and dysphagia. Family history revealed that her mother died of esophageal carcinoma and at least two-thirds of her relatives have had similar symptoms for varying durations. She most probably has:

A. ocular pharyngeal syndrome

B. Plummer-Vinson syndrome

C. Patterson-Kelly syndrome

D. achalasia

E. scleroderma.

53. A 36-year-old woman was diagnosed as having a frontal lobe tumor. Among other symptom, she has anosmia, ipsilateral optic atrophy, and contralateral papilledema. This constellation of symptoms has been referred to as:

A. Avellis' syndrome

15 B. Tapia syndrome

C. Vernet's syndrome

D. Foster-Kennedy syndrome

E. Collet-Sicard syndrome.

54. A 6-year-old girl is noted to have low-set ears, large ear lobes, possible ossicular deformity, web neck, short stature, and renal symptoms. Her chromosome abnormality is:

A. XXY

B. XO

C. trisomy 21

d. trisomy 13

E. trisomy 18.

55. A 7-year-old Israeli boy is noted to have low-set ears, probable ossicular deformity, and to be of short stature. The geneticist concluded that the patient has a polysaccharide metabolic problem which is inherited autosomal recessively. Among other findings, which one of the following will be noted?:

A. polydipsia, polyuria

B. hypoglycemia

C. chondroitin sulfate in the urine

D. trypsin in the stool

E. calcification of the sella.

56. Apert's syndrome (acrocephalosyndactyly) has all of the following characteristics EXCEPT:

A. autosomal recessive

B. hearing loss present at birth

C. conductive hearing loss

D. patent cochlear aqueduct

E. flat audiometric pattern.

16 57. All of the following syndromes are associated with hearing loss and renal abnormalities EXCEPT:

A. Apert's syndrome

B. Weil's syndrome

C. Turner's syndrome

D. Leopard syndrome

E. Fanconi's syndrome.

58. A 3-year-old white male is noted to have severe sensorineural hearing loss, retinitis pigmentosa, obesity, and diabetes. This is believed to be autosomal recessive. The most likely diagnosis is:

A. Usher's syndrome

B. Apert's syndrome

C. Alstrom's syndrome

D. Waardenburg's syndrome

E. Wallenberg's syndrome.

62. The auricle is mainly supplied by:

A. postauricular and facial arteries.

B. postauricular artery and superficial temporal artery

C. occipital and postauricular arteries

D. occipital, postauricular, and facial arteries

E. anterior tympanic and posterior tympanic arteries.

63. A 10-year-old white girl presents with a sudden onset of fever, loss of appetite, dysphagia, pharyngitis, mild abdominal pain, and nausea and vomiting. Vesiculopapular lesions measuring 1-2 mm in diameter are present on the oral mucosa. These lesions soon would break down giving rise to grayish yellow ulcers. The disease is thought to be caused by:

A. virus herpes simplex

B. Vincent's organisms

17 C. Haemophilus influenzae

D. Coxsackie virus

E. measles.

64. Theoretically a patient with ossicular disontinuity with an intact tympanic membrane will present with a conductive loss of about:

A. 45 dB

B. 30 dB

C. 60 dB

D. 85 dB

E. 50 dB.

65. The most frequent cause of death in acute otitis media is:

A. sigmoid sinus thrombosis

B. meningitis

C. temporal lobe abscess

D. cerebellar abscess

E. brain abscess in general.

66. Other than coalescent mastoiditis, the most common complication of acute otitis media is:

A. subdural abscess

B. meningitis

C. sigmoid sinus thrombosis

D. extradural abscess

E. temporal lobe abscess.

67. Other than meningitis, the most common cause of death in acute otitis media is:

A. lateral sinus thrombophlebitis

18 B. temporal lobe abscess

C. cerebellar abscess

D. extradural abscess

E. subdural abscess.

68. A 50-year-old white male presents with a suppurative left ear for 10 days. His temperature has spiked to 103° twice a day for the past 4 days. His hemoglobin is 10.5 g%. He appears emaciated: palpation of the mastoid process reveals edema and pain in this area. The most likely diagnosis is:

A. mastoiditis

B. lateral sinus thrombosis

C. subdural abscess

D. meningitis

E. none of these.

69. A 45-year-old white, right-handed male developed right mastoiditis secondary to chronic otitis media. Culture grew Pseudomonas sp. In spite of aggressive treatment with carbenicillin (Geopen) and gentamicin, he developed severe headache, Jacksonian convulsions, rise in blood pressure, and slowing of the pulse rate. The neurologist entertained the diagnosis of right temporal lobe abscess. Besides other symptoms, he most probably would have:

A. ataxia

B. aphasia

C. paresis and numbness of the left side

D. spontaneous nystagmus

E. all of the above.

70. A 20-year-old diabetic developed a fulminating coalescent mastoiditis. In this age group, the chances of having pneumatization of the petrous pyramid is:

A. 10%

B. 30%

C. 50%

19 D. 75%

E. 90%.

71. A Pancoast's tumor of the lung is one:

A. located in the right middle lobe

B. located in the apex

C. of "oat cell" type

D. of "alveolar cell" type

E. can be of any cell type.

72. A 27-year-old girl developed a slow-growing nontender mass in the parapharyngeal space. This mass can be palpated in the lateral pharyngeal wall as well as behind the angle of the mandible. The most likely pathologic diagnosis is:

A. neurolemmoma

B. mixed tumor

C. fibroma

D. leiomyoma

E. lymphoma.

73. Subtotal thyroidectomy is preferred for treatment of Graves' disease in:

A. patients of child-bearing age

B. in those intolerant of antithyroid drugs

C. failure of antithyroid drugs to induce remission

D. noncompliers of drug instruction

E. all of the above.

E. All of the above. Subtotal thyroidectomy is preferred for younger patients of child- bearing age; in patients in whom antithyroid drugs, despite prolonged use, have failre to induce a remission; in those intolerant of antithyroid drugs; in those fearful of radiation effects in any form; and in noncompliers of drug administration instructions.

20 74. A 20-year-old female developed a very slowly enlarging left malar region. A routine laboratory workup revealed elevated serum alkaline phosphatase, with normal Ca and P. Which one of the following situations is most likely?

A. Increased osteoblastic activity

B. Malignant degeneration

C. Increased osteoclastic activity

D. Increased osteoclastic and osteoblastic activity

E. Part of the usual profile of this disease entity.

75. Squamous cell carinoma has been reported in the auricle, external auditory canal, and middle ear. Among these regions the incidence of carcinoma of the middle ear is:

A. 70%

B. 50%

C. 30%

D. 10%

E. 2%.

76. A 60-year-old alcoholic developed a squamous cell carcinoma of the hard palate. The primary and early site of lymphatic drainage would be:

A. subdigastric

B. retropharyngeal

C. submaxillary

D. subparotid

E. high jugular chain.

77. An 80-year-old male has multiple areas of senile keratosis. He is concerned and consulted an otolaryngologist regarding the chances of malignant degeneration. A well- informed otolaryngologist would give an estimated figure of:

A. 1% malignant degeneration rate

B. 5% malignant degeneration rate

21 C. 10% malignant degeneration rate

D. 20% malignant degeneration rate

E. 50% malignant degeneration rate.

78. A 32-year-old white male presents with multiple cysts of the jaw and multiple basal carcinomas of the skin. X-ray shows abnormal ribs and abnormal metacarpals. This condition is:

A. autosomal recessive

B. autosomal dominant

C. nonhereditary

D. associated with xeroderma pigmentosa

E. sex-linked recessive.

79. Carcinoma of the nasopharynx often involves:

A. the node of Rouvier

B. the node of Delphian

C. the node of Krause

D. all of these

E. none of these.

A. The node of Rouvier.

Rouvier's Node: Lateral retropharyngeal node. It is a common target of metastases in nasopharyngeal carcinoma.

80. A 50-year-old male presents with unilateral left nasal obstruction and left facial swelling. The Ohngren's line is used to:

A. stage the tumor

B. correlate site of tumor and its aggressiveness

C. classify metastasis

D. classify the histologic nature of the tumor

22 E. none of the above.

81. A student of head and neck oncology should be aware of the lymphatics. It has been demonstrated that certain regions have richer lymphatic drainage than others. In order of decreasing amount of lymphatics, the following is correct:

A. pyriform sinus, base of tongue, supraglottic, subglottic

B. base of tongue, pyriform sinus, supraglottic, subglottic

C. pyriform sinus, subglottic, supraglottic, glottic

D. transglottic, subglottic, supraglottic, glottic

E. postcricoid, pyriform sinus, supraglottic, subglottic.

82. Referred otalgia is frequently encountered in an otolaryngology practice. Referred pain from a base of tongue lesion involves the:

A. gasserian ganglion

B. petrosal ganglion

C. sphenopalatine ganglion

D. otic ganglion

E. nodose ganglion.

83. A 50-year-old male with a left false cord squamous cell carcinoma is undergoing pulmonary function testing as a preoperative workup. The vital capacity is:

A. the same as tidal volume

B. the sum of tidal volume and inspiratory reserve volume

C. the sum of tidal volume and residual volume

D. the sum of tidal volume, inspiratory reserve volume, and expiratory reserve volume

E. the same as inspiratory capacity.

D. The sum of tidal volume, inspiratory reserve volume, and expiratory reserve volume.

84. A 60-year-old Southern male has worked on a cotton plantation and in a cotton plant for the past 40 years. He was admitted to a hospital recently for chronic cough and

23 pulmonary insufficiency. X-ray showed scattered diffuse infiltrates and emphysematous changes. This condition has been referred to as:

A. bagassosis

B. bysinosis

C. berylliosis

D. anthracosis

E. sarcoidosis.

A. Bagassosis.

85. The SISI test is characterized by all of the following EXCEPT:

A. SISI score higher than 60% in sensory hearing loss

B. lone SISI score in typical neurallesion

C. the test is performed at 20 dB above threshold

D. the test is performed at 2000 Hz

E. the test can be used in both unilateral hearing loss and bilateral hearing loss.

86. The tone decay test is characterized by all of the following EXCEPT:

A. performed at 20 dB above threshold

B. a tone decay of 40 dB suggests a neural pathology

C. the score is the number of decibel increase that is needed to maintain the tone for 60 seconds

D. can be performed at any frequency

E. patients with Ménière's disease usually do not have a high tone decay score.

87. Interaural attenuation is about:

A. 15 dB

B. 20 dB

C. 30 dB

24 D. 50 dB

E. 70 dB.

89. A 30-year-old female is being evaluated by an otolaryngologic allergist for seasonal "sneezing, allergic rhinitis, watery eyes, and itchy nose". Her symptoms are present mainly in the spring. She is most likely allergic to:

A. ragweed

B. grass pollen

C. tree pollen

D. mold

E. all of these.

90. During the process of anaphylactic shock, all of the following take place EXCEPT:

A. peripheral vasodilatation

B. release of histamine

C. injury to the vascular endothelium

D. intravascular coagulation

E. smooth muscle contraction.

91. Antihistamine is prescribed by many otolaryngologists for allergic and vasomotor rhinitis. The mechanism of action of this medication:

A. inhibits the formation of histamine

B. hydrolyzes histamine

C. competes with histamine for the tissue sites

D. is anti-inflammatory

E. is unknown.

92. Glucocorticoids have been used by many otolaryngologists for many "allergic" states. The rationale for this practice embraces all the following EXCEPT:

A. anti-inflammatory

25 B. alters the antibody-antigen reaction

C. releases enzymes that metabolize histamine

D. retards the formation of histamine in the mast cells

E. suppresses tissue edema.

93. A young otolaryngologist is performing a mastoid-tympanoplasty under general anesthesia utilizing halothane. A safe amount of 1% lidocaine (Xylocaine) with 1:100,000 epinephrine for infiltration would be no more than:

A.1mL

B.5mL

C. 10 mL

D. 30 mL

E. 50 mL.

94. The muscles involved in the function of the eustachian tube include all of the following EXCEPT:

A. tensory tympani

B. tensor palati

C. levator palati

D. salpingopharyngeus

E. salpingopalatus.

A. Tensory tympani.

95. A 19-year-old college student presents with peritonsillar abscess. His trismus is particularly due to involvement of:

A. external pterygoid muscle

B. internal pterygoid muscle

C. masseter muscle

D. buccinator muscle

26 E. palatoglossus and palatopharyngeus muscles.

96. The middle thyroid artery is derived from:

A. thyrocervical trunk

B. external carotid artery

C. superior thyroid artery

D. inferior thyroid artery

E. none of these.

97. The jugular foramen is bounded by the:

A. occipital bone only

B. temporal bone only

C. sphenoid bone only

D. occipital bone medially and temporal bone laterally

E. sphenoid bone medially and temporal bone laterally.

D. occipital bone medially and temporal bone laterally

98. All of the following pass through the jugular foramen EXCEPT:

A. inferior petrosal sinus

B. IX

C. X

D. posterior meningeal artery

E. XII.

E. XII.

The jugular foramen is bound medially by the occipital bone and laterally by the temporal bone. The foramen is divided into anteromedial (pars nervosa) and posterolateral (pars vascularis) areas by a fibrous or bony septum. The medial area transmits nerves IX, X, and XI as well as the inferior petrosal sinus. The posterior compartment transmits the internal jugular vein and the posterior meningeal artery. The right foramen is usually slightly larger than the left foramen.

27 99. The facial nerve trunk can be located:

A. medial to the styloid process

B. 6-8 mm medial to the petrotympanic fissure

C. 6-8 mm inferior to the petrotympanic fissue

D. 6-8 mm inferomedial to the tympanomastoid fissure

E. superior to the tragal cartilage.

D. 6-8 mm inferomedial to the tympanomastoid fissure.

In parotid surgery, the facial nerve can be identified at 6-8 mm below the inferior "drop off" of the tympanomastoid fissure. This was described by H. G. Tabb.

100. A 35-year-old female with a past history of heavy smoking presents with intermittent hemoptysis. The most likely diagnosis is:

A. bronchiectasis

B. bronchial adenoma

C. tracheobronchitis

D. tuberculosis

E. mitral stenosis.

101. The blood supply of the esophagus includes all EXCEPT:

A. inferior thyroid artery

B. internal mammary artery

C. intercostal artery

D. left gastric artery

E. left inferior phrenic artery.

102. The most common site of esophageal carcinoma is:

A. upper one-third

B. middle one-third

28 C. lower one-third

D. cervical

E. esophagogastric junction.

103. Anomaly of the great vessels is one of the common causes of dysphagia and/or dyspnea. The most frequent type of this is:

A. anomalous innominate artery

B. double aortic arch

C. anomalous subclavian artery

D. right aortic arch

E. pulmonary artery compression.

104. A 30-year-old black male presents with dysphagia. Thorough diagnostic studies reveal a posterior mediastinal tumor. The most likely preoperative diagnosis would be:

A. dermoid or teratoma

B. lymphoma

C. bronchial cyst

D. pericardial cyst

E. neurolemmoma.

105. Which one of the following is correct?

A. The right middle lobe has three segments, righ lower lobe has four segments.

B. The left upper lobe has three segments, left lower lobe has four segments, right upper lobe has two segments.

C. The right upper lobe has three segments, right lower lobe has five segments, left upper lobe has four segments.

D. The left lower lobe has three segments and right middle lobe has three segments.

E. Right lower lobe has four segments and left lower lobe has four segments.

106. The PTT test measures all the factors listed in:

29 A. VII, VIII, IX, X, XI, XII

B. V, VIII, IX, X, XI, XII

C. V, VII, IX, X

D. VII, VIII, X, XI, XII

E. V, IX, X, XI, XII.

107. Christmas disease or hemophilia B is:

A. autosomal recessive and lack of Factor IX

B. sex-linked recessive and lack of Factor IX

C. autosomal recessive and lack of Factor XI

D. sex-linked recessive and lack of Factor XI

E. sex-linked recessive and lack of Factor VIII.

108. A 20-kg boy underwent tonsillectomy and adenoidectomy. The estimated blood loss was 500 mL. This represents:

A. 35% of his blood volume; he should require transfusion therapy

B. 35% of his blood volume; he should require no transfusion therapy

C. 20% of his blood volume; he should require transfusion therapy

D. 20% of his blood volume; he should require no transfusion therapy

E. 15% of his blood volume; he should require no transfusion therapy.

109. Chloromycetin:

A. is bactericidal and it disrupts the cell wall

B. is bacteriostatic and it disrupts the cell wall

C. is bactericidal and it disrupts protein synthesis

D. is bacteriostatic and it disrupts protein synthesis

E. disrupts the cell membrane.

30 110. Inner ear congenital anomalies have been classified by otologic histopathologists. The Schiebe's type demonstrates:

A. complete bony and membranous degeneration

B. incomplete bony and membranous degeneration

C. membranous cochlear and saccular degeneration

D. membranous vestibular aplasia

E. membranous cochlear aplasia.

111. The inner ear anomaly secondary to maternal rubella is most similar to the type classified as:

A. Michel's

B. Mundini-Alexander

C. Schiebe's

D. Bing-Siebermann

E. Alexander's.

112. An otolaryngologist counseling the parents of a congenitally deaf child was asked the frequency of a "deaf" gene in the general population. The answer should be one in:

A. 100 people carries a recessive deaf gene

B. 50 people carries a recessive deaf gene

C. 25 people carries a recessive deaf gene

D. 8 people carries a recessive deaf gene

E. 4 people carries a recessive deaf gene.

113. A 43-year-old mother gave birth to a 9-lb girl. The child is mentally retarded and of short stature. At 15 years of age she still has not shown signs of frontal sinus development. This syndrome is due to:

A. abnormal G group chromosomes

B. abnormal E group chromosomes

C. Patau's syndrome

31 D. XO

E. trisomy 17.

114. A young expectant housewife contracted rubella in the first trimester. She is frightened and consulted the obstetrician regarding the wisdom of a therapeutic abortion. Among weighing the chances of other anomalies, the obstetrician wants to know the risk of hearing loss in this newborn. It is:

A. 75%

B. 50%

C. 40%

D. 20%

E. 10%.

115. An ataxic 30-year-old male died of renal failure. At autopsy he was noted to have cystic kidneys, angioma of the cerebellum, and scattered petechiae of the skin. This condition has been referred to as:

A. Rendu-Osler-Weber syndrome

B. Sturge-Weber syndrome

C. neurofibromatosis

D. Hippel-Lindau disease

E. Stevens-Johnson syndrome.

116. Jervell-Lang-Nielson syndrome includes all of the following characteristics EXCEPT:

A. autosomal recessive

B. bilateral deafness

C. renal failure

D. recurrent syncope

E. abnormal ECGs.

32 117. A mentally retarded 10-year-old child is noted to have mixed hearing loss, exophthalmos, parrot-beaked nose, small maxilla, and mandibular prognathism. This syndrome is autosomal dominant and is called:

A. Crouzon's disease

B. Treacher Collin's disease

C. Mohr's syndrome

D. Pendred's syndrome

E. Pierre Robin syndrome.

118. Trautmann's triangle is:

A. formed by the three semicircular canals

B. formed by the superior petrosal sinus, sigmoid sinud, and the bony labyrinth

C. formed by the tegment and the sigmoid sinus

D. formed by the spine of Henle, temporal line, and posterior osseous external auditory canal

E. formed by the superior petrosal sinus, inferior petrosal sinus, and the sigmois sinus.

120. Muscles attached to the temporal bone include all of the following EXCEPT:

A. posterior digastric muscle

B. temporal muscle

C. longus capitis muscle

D. sternocleidomastoid muscle

E. trapezius muscle.

121. All of the following are attached to the malleus EXCEPT:

A. lateral malleal ligament

B. superior malleal ligament

C. anterior malleal ligament

D. posterior malleal ligament

33 E. tensor tympani tendon.

122. The works of Bruce Proctor demonstrated that there are:

A. 5 malleal folds and 4 incudal folds

B. 4 malleal folds and 4 incudal folds

C. 4 malleal folds and 3 incudal folds

D. 5 malleal folds and 5 incudal folds

E. 3 malleal folds and 2 incudal folds.

123. The anterior pouch of von Troltsch is between the:

A. pars flaccida and superior malleal fold

B. pars tensa and anterior malleal fold

C. pars tensa and anterior malleal ligament

D. pars flaccida and anterior malleal ligament

E. short process of the malleus and chord tympani.

124. Prussak's space is bounded by:

A. lateral malleal fold, superior malleal ligament, neck of malleus, and Shrapnell's membrane

B. pars flaccida and anterior malleal fold

C. pars tensa and anterior malleal fold

D. lateral malleal fold, lateral process of the malleus, the neck of the malleus, and Shrapnell's membrane

E. lateral malleal fold, lateral process of the malleus, the long process of the malleus, and pars tensa.

125. The blood supply of the middle ear and mastoid includes all of the following EXCEPT:

A. caroticotympanic artery

B. middle meningeal artery

34 C. stylomastoid artery

D. deep auricular artery

E. ascending pharyngeal artery.

126. Russell's bodies are found in:

A. rhinoscleroma

B. rhinosporosis

C. ameloblastoma

D. acoustic neurinoma

E. papillary carcinoma of the thyroid.

A. Rhinoscleroma. Russell's Bodies: Eosinophilic, round structures, associated with plasma cells found in rhinoscleroma.

127. A 40-year-old male presents with recurrent papilloma of the left nasal fossa. He reportedly had two previous intranasal surgical excisions. The biopsy report indicated it to be inverting papilloma. In counseling the patient regarding surgical therapy, the otolaryngologist was asked about the risk of this lesion turning malignant. The answer is:

A. 0.1%

B. 4%

C. 13%

D. 20%

E. 50%.

128. The cells described in the lesion of Ques. 127 are rich in:

A. lipids

B. hyaluronic acid

C. chondroitin sulfate

D. glycogen

E. none of these.

35 129. A young patient is noted to have dysphagia, regurgitation, but no dyspnea. Barium swallow and angiography revealed an indentation of the posterior esophagus. This condition could be:

A. double aortic arch

B. anomalous innominate artery

C. dysphagia lusoria

D. scleroderma

E. Barrett's syndrome.

130. A 10-year-old boy was brought to see an otolaryngologist because of unilateral ptosis since birth. However, upon opening the lower jaw to the contralateral side, the ptotic lid is elevated. A paternal uncle has the same symptoms. This pattern of symptomatology has been referred to as:

A. Marcus' Gunn's syndrome

B. Horner's syndrome

C. Wartenberg's syndrome

D. Melkerson's syndrome

E. Richards-Rendell syndrome.

131. The axillary sheath is an extension of:

A. the superficial layer of the deep fascia

B. the visceral fascia

C. the pretracheal fascia

D. the prevertebral fascia

E. none of the above.

132. In studying achondroplastic dwarfs, it is of interest to determine the derivation of the various bones. All of the following are membranous EXCEPT:

A. sphenoid

B. frontal

36 C. mandible

D. zygoma

E. mastoid process.

133. A 16-year-old girl was hit in the left eye by a golf ball. She suffered a left blow- out fracture that necessitated surgical correction. At the time of surgery, it is not only important to know the anatomic landmarks but the nerves and vessels associated with each landmark. The superior orbital fissure transmits all of the following EXCEPT:

A. III

B. IV

C. VI

D. V second division

E. ophthalmic vein.

D. V second division.

134. Congenital esophageal stenosis is a very rare condition. It is most commonly located at the:

A. cervical esophagus and treated with surgery

B. cervical esophagus and treated with dilatation

C. junction of the middle and distal thirds and best treated with dilatation

D. esophagogastric junction and best treated with surgery

E. esophagogastric junction and best treated with dilatation.

135. An otolaryngology resident rotating through a large facial deformity clinic will see more patients having a:

A. cleft lip with cleft palate than having a cleft lip alone

B. cleft lip than having a cleft palate

C. cleft palate than having a cleft lip and cleft palate

D. cleft lip than having cleft lip with cleft palate

E. cleft palate than having a cleft lip.

37 A. Cleft lip with cleft palate than having a cleft lip alone.

E. Cleft palate than having a cleft lip.

Cleft lip with cleft palate is the most common; cleft palate alone is next; cleft lip alone is the least common.

136. A 45-year-old male was admitted by the internist to the hospital because of ascites, diarrhea, asthmalike symptoms, and episodic flushing. He also was noted to be hoarse and on physical examination a mass was noted on the right true cord. He has a past history of having an intra-abdominal tumor removed. A biopsy was taken of this tumor of the larynx and it was not a squamous cell carcinoma. This tumor most likely secretes:

A. epinephrine

B. norepinephrine

C. thyrocalcitonine

D. serotonin

E. histamine.

D. Serotonin.

Carcinoid Syndrome. The symptoms include episodic flushing, diarrhea, and ascites. The tumor secretes serotonin. The treatment is wide excision. The tumor may give a positive DOPA reaction.

137. A 9-year-old girl was noted to have multiple recurrent upper respiratory and lower respiratory infections. She has had three nasal polypectomies in the past. She is treated with high-protein, low-fat diet with supplementary water-soluble vitamins and pancreatic extracts. Which one of the following describes her condition?

A. Autosomal-recessive inheritance

B. Elevated trypsin

C. Serotonin noted in the stool in 10-15% of patients with this disease

D. Chondroitine sulfate can be measured in the urine

E. None of the above.

138. A 6-year-old girl was referred to an otolaryngologist because of hearing loss. Audiometric studies revealed a 40 dB conductive loss in the left ear. She also was noted to have downward-sloping palpebral fissures, depressed cheek bones, deformed pinnas, receding chin, and large fishlike mouth. She has:

38 A. Crouzon's disease

B. Pierre Robin syndrome

C. Franceschetti's syndrome

D. Mohr's syndrome

E. none of these.

39. A 65-year-old refugee from Cuba seeks the help of an otolaryngologist because of nasal crusting and nasal obstruction. On examination he was noted to have atrophic rhinitis. One of the organisms causing this condition is:

A. Klebsiella ozaenae

B. Klebsiella pneumoniae

C. Klebsiella rhinoscleromatis

D. Rhinosporidium seeberi

E. Rhinosporidium kinealyi.

140. Surgical treatment is indicated in patients with thyroiditis:

A. to relieve pressure symptoms

B. to exclude malignancy

C. for cosmetic reasons

D. none of the above

E. all of the above.

141. A 35-year-old female presents with vague vertiginous symptoms and abnormal articulation. She was noted to have spontaneous nystagmus, scanning speech, intention tremor, and mild ataxia. A likely diagnosis is:

A. myasthenia gravis

B. amyotrophic lateral sclerosis

C. multiple sclerosis

D. bulbar polio

39 E. Wallenberg's syndrome.

42. Oroantral fistulae are encountered in both an otolaryngologic and an oral surgical practice. The tooth most commonly incriminated for this pathologic entity is:

A. canine

B. first premolar

C. second premolar

D. first molar

E. second molar.

143. The parasympathetic secretory fibers to the parotid are carried by:

A. greater superficial petrosal nerve

B. chorda tympani

C. auriculotemporal nerve

D. branches of V (second division)

E. none of the above.

144. The solitary tract nucleus is the nucleus of:

A. secretory fibers to the lacrimal gland

B. secretory fibers to the salivary gland

C. taste fibers of VII

D. taste fibers of IX

E. taste fibers of VII and IX.

145. The Edinger-Westphal nucleus is the:

A. motor nucleus of III

B. parasympathetic nucleus of III

C. motor nucleus of V

D. sensory nucleus of V

40 E. secretory nucleus of IX.

146. The innervation of the intrinsic laryngeal muscles is from the:

A. glossopharyngeal nerve

B. vagus nerve

C. bulbar portion of the accessory nerve

D. cervical portion of the accessory nerve

E. recurrent laryngeal nerve only.

147. Cavernous sinus thrombosis is more often than not a fatal complication of ethmoiditis. All of the following structures are in intimate relationship with this sinus EXCEPT

A. internal carotid artery

B. ophthalmic artery

C. II nerve

D. III nerve

E. V nerve.

???E.Vnerve. V1 is involved not V.

148. All of the following constitute the muscles of the uvula EXCEPT:

A. palatoglossus

B. muscle uvula

C. tensor palati

D. levator palati

E. stylopharyngeus.

E. Stylopharyngeus.

149. The pterygomandibular raphe is made up of the:

A. medial and lateral pterygoid muscles

41 B. buccinator and the superior constrictor muscles

C. middle constrictor muscle and the posterior pharyngeal wall

D. superior constrictor muscle and the posterior pharyngeal wall

E. superior and middle constrictor muscles.

B. Buccinator and the superior constrictor muscles.

150. The anterior and posterior ethmoidal foramina are located within the:

A. frontal bone

B. ethmoid bone

C. sphenoid bone

D. lacrimal bone

E. nasal bone.

151. The blood supply of the nasopharyngeal tonsil includes all of the following EXCEPT:

A. ascending palatine artery

B. ascending pharyngeal artery

C. internal maxillary artery

D. thyrocervical trunk

E. lingual artery.

152. The tonsils are supplied by many vessels, but the main blood supply is from:

A. facial artery

B. lingual artery

C. internal maxillary artery

D. ascending pharyngeal artery

E. none of these.

42 153. Zenker's diverticulum is one of the causes of dysphagia. It commonly occurs at the so-called Killian's dehiscence. This area of weakness is between:

A. the cricopharyngeus and the muscles of the esophagus

B. the cricopharyngeus and the inferior constrictor

C. the cricopharyngeus and the thyropharyngeus muscle

D. the middle and inferior constrictors

E. none of the above.

154. A 45-year-old female gives a history of recurrent parotid swelling with mild pain. Examination revealed an inflamed Stensen's duct. No opaque calculus was identified. Sialography revealed chronic sialectasis. Culture of the ductal orifice during an exacerbation would most likely yield:

A. beta-hemolytic streptococcus, group A

B. Streptococcus viridans

C. Staphylococcus albus

D. Staphylococcus aureus

E. Pneumococcus.

155. An otolaryngologist was asked to see a newborn with a "catlike" cry. He appeared to be microcephalic with cleft lip and palate. He had mild inspiratory stridor which the otolaryngologist diagnosed as laryngomalacia. This constellation of symptoms is due to abnormality of:

A. B group of chromosomes

B. D group of chromosomes

C. E group of chromosomes

D. G group of chromosomes

E. none of these.

A. B group of chromosomes.

Cri du Chat Syndrome. A condition caused by a B group chromosome with a short arm, its symptoms are mental retardation, respiratory stridor, microcephaly, hypertelorism, midline oral clefts, and laryngomalacia with poor approximation of the posterior vocal cords.

43 156. It is not infrequent for a pathologist to notice Trichinella within muscle tissues. A certain percentage of routine autopsies have yielded this finding. This figure is estimated to be:

A. 1%

B. 5%

C. 15%

D. 30%

E. 50%.

157. The greater cornu of the hyoid bone is believed to be derived from the:

A. first branchial arch

B. second branchial arch

C. third branchial arch

D. third branchial pouch

E. fourth branchial arch.

159. The oral tongue is a(n):

A. ectodermal derivative

B. entodermal derivative

C. mesodermal derivative

D. ectodermal and mesodermal derivative

E. entodermal and mesodermal derivative.

160. The inferior turbinate is believed to be derived from:

A. first ethmoturbinal

B. second ethmoturbinal

C. third ethmoturbinal

D. nasoturbinal

44 E. maxilloturbinal.

E. Maxilloturbinal.

Embryonic Anlagen and Their Derivatives

Maxilloturbinal Inferior concha

First ethmoturbinal Middle concha

Second and third ethmoturbinal Superior concha

Fourth and fifth ethmoturbinal Supreme concha

Nasoturbinal Agger nasi area.

161. Certain parts of the temporal bone are derived from cartilage while other parts are membranous bone. All of the following are membranous bone EXCEPT:

A. petrous pyramid

B. squamos

C. tympanic ring

D. osseous canal

E. bony modiolus.

162. The concha is derived from the:

A. first branchial arch

B. first branchial groove

C. second branchial arch

D. second branchial groove

E. second branchial pouch.

163. The first of the membranous labyrinth to appear is the:

A. cochlea

B. saccule

C. utricle

45 D. endolymphatic duct

E. cochlear aqueduct.

164. A 12-year-old white male presents with recurrent suppuration from his left ear and exophthalmos. Examination revealed a normal tympanic membrane with polyps in the osseous external auditory canal. Mastoid X-ray was unremarkable though some "punched out" lesions were noted in the occipital and parietal regions. Upon closer questioning he was found to have diabetes insipidus. The most likely diagnosis is:

A. neurofibromatosis

B. Hand-Schüller-Christian disease

C. pituitary adenoma

D. "canal" cholesteatoma

E. polyostotic fibrous dysplasia.

165. The preepiglottic space is an important anatomic landmark in regard to the spread of laryngeal carcinoma. It is bounded by all of the following EXCEPT:

A. vallecula

B. hyoid bone

C. thyrohyoid membrane

D. hyoepiglottic ligament

E. pharyngoepiglottic ligament.

166. The most common cause of chronic laryngeal stenosis is:

A. trauma

B. high tracheotomy

C. congenital

D. tuberculosis

E. syphilis.

167. A 60-year-old depressed woman drank "Drano" in a suicidal attempt. Fortunately, she was brought to the emergency room less than 1 hour after ingestion. On esophagoscopy definite burns were ascertained. The esophagus is weakest:

46 A. one hour after ingestion

B. first 48 hours after ingestion

C. first week after ingestion

D. second week after ingestion

E. fourth week after ingestion.

168. A 60-year-old heavy smoker gave a history of 1 month's hoarseness. Examination revealed a fungating, warty, well-differentiated squamous cell carcinoma of the left true cord. The anterior commissure was clear. The cord was somewhat fixed. No lymphadenopathy was noted. The diagnosis of verrucouos carcinoma was made histologically. This should be treated with:

A. radiation

B. radiation and laryngectomy

C. laryngectomy

D. hemilaryngectomy

E. hemilaryngectomy and left radical neck dissection.

169. Congenital laryngeal cyst is most frequently found in:

A. the epiglottis

B. the aryepiglottic folds

C. the glottis

D. the subglottis

E. variable.

170. Upon phonation, indirect laryngoscopy revealed incomplete closure of the posterior larynx. Which one of the following intrinsic muscles is paralyzed?

A. Interarytenoideus muscle

B. Lateral cricoarytenoid muscle

C. Thyroarytenoid muscle

D. Cricothyroid muscle

47 E. Posterior cricoarytenoid muscle.

171. Pseudohyperparathyroidism is the syndrome resulting from:

A. laboratory error

B. elevated uric acid

C. secretion of PTH-like substances from nonparathyroid tumors

D. excess calcium ingestion

E. excess vitamin D ingestion.

C. Secretion of PTH-like substances from nonparathyroid tumors. Pseudohyperparathyroidism refers to the hyperparathyroid state resulting from the secretion of parathormone or parathormonelike substance by a variety of nonparathyroid tumors.

172. Infectious mononucleosis has been associated with all of the following EXCEPT:

A. ruptured spleen

B. Guillain-Barre syndrome

C. hepatomegaly

D. exophthalmos

E. Paul-Bunnel test.

173. A diabetic mother gave birth to a premature baby who developed severe respiratory distress. The baby was treated with humidified oxygen. In view of an otherwise negative physical examination, the most likely diagnosis was idiopathis respiratory distress syndrome. The pulmonary tissues in this disease lack:

A. creatinine phosphokinase

B. alpha-lecithin

C. acid mucopolysacharides

D. trypsin

E. none of these.

174. Cupulolithiasis is an entity believed to be due to:

A. dislodgement of the statoconia of the saccule to the horizontal canal

48 B. dislodgement of the statoconia of the saccule to the posterior canal

C. dislodgement of the statoconia of the utricle to the horizontal canal

D. dislodgement of the statoconia of the utricle to the posterior canal

E. free-floating statoconia in all three semicircular canals.

175. Isolated otosclerosis of the footplate is encountered in approximately:

A. 50% of the cases

B. 30% of the cases

C. 10% of the cases

D. 5% of the cases

E. 1% of the cases.

176. The mother of a family of four has clinical otosclerosis. All four children are in the first decade. What are the chances of the children having clinical otosclerosis ultimately? The father is asymptomatic.

A. 75%

B. 60%

C. 50%

D. 20%

E. 5%.

177. The maximum output of a 512 tuning fork is:

A. 50 dB

B. 60 dB

C. 70 dB

D. 80 dB

E. 90 dB.

178. The maximum increase in pressure occurs when the sound has a wave-length x times that of the length of the external auditory canal. The value of x is:

49 A. 1

B. 2

C. 3

D. 4

E. 10.

179. Streptomycin sulfate has successfully been used to treat bilateral incapacitating Ménière's disease. Which part of the membranous labyrinth is most sensitive to this medication?

A. Endolymphatic duct and sac

B. Samicircular canals

C. Saccule

D. Utricle

E. Cochlea.

180. A 32-year-old man has a two-month history of hoarseness. Direct laryngoscopy revealed a mass in the left posterior larynx on the true cord. Biopsy is as shown. This lesion is considered to have a potential for malignant degeneration. The incidence for this has been estimated to be:

A. 0.5%

B. 1%

C. 3%

D. 10%

E. 15%.

181. Anosmia has been associated with all of the following EXCEPT:

A. Turner's syndrome

B. Kalman's syndrome

C. Foster-Kennedy syndrome

D. atrophic rhinitis

50 E. vitamin E deficiency.

182. The causes for macroglossia include all of the following EXCEPT:

A. myxedema

B. amyloidosis

C. Behcet's syndrome

D. von Gierke's disease

E. tertiary syphilis.

183. All of the following diseases may have sensorineural hearing loss EXCEPT:

A. brucellosis

B. myxedema

C. Wilson's disease

D. trichinosis

E. relapsing polychondritis.

184. The most comfortable and healthy environment is:

A. 50% humidity at 70-75°F

B. 70% humidity at 70-75°F

C. 30% humidity at 70-75°F

D. 10% humidity at 80°F

E. none of these.

185. The following statements are consistent with Ewald's laws EXCEPT:

A. the horizontal canal is maximally stimulated by ampullopetal flow

B. the posterior canal is maximally stimulated by ampullofugal flow

C. whan a labyrinth is maximally stimulated, it elicits nystagmus toward itself

D. the superior canal is maximally stimulated by ampullofugal flow

51 E. the utricle and saccule are maximally stimulated by ampullopetal flow.

186. A 42-year-old female presents with bilateral sensorineural hearing loss, saddle nose, tender auricle, and hoarseness. Among other findings she may be noted to have:

A. increase in urinary chondroitin sulfate

B. increase in urinary acid mucopolysaccharide

C. increase in glycogen content in the pathologic cells

D. increase in mucopolysaccharides in the subepithelial tissues

E. increase in amount of trypsin in her stool.

187. A 20-year-old boy was noted to have cafe au lait spots throughout his trunk and extremities. He has multiple subcutaneous nodules and has elevated diastolic blood pressures. At the age of 15 he was operated upon for intussusception. There is a definitive positive familial history for similar disorders. His hypertension is most likely secondary to:

A. pheochromocytoma

B. renal disease

C. early onset arteriosclerotic vascular disease

D. insensitive carotid sinus apparatus

E. unknown etiology.

188. The membranous labyrinth is derived from:

A. ectoderm

B. mesoderm

C. entoderm

D. ectoderm and mesoderm

E. ectoderm and entoderm.

189. The Reinke's space in the larynx is:

A. located in the ventricle

B. similar to the preepiglottic space

52 C. perpendicular to the long axis of the true cord

D. limited above and below by the linea arcuata

E. situated between the deeper elastic layer and thyroarytenoid muscle.

190. A 32-year-old woman underwent an uneventful stapedectomy. She experienced mild dizziness and sensorineural hearing loss for the first 7 days postoperatively. The most likely diagnosis and treatment is:

A. fistula of the oval window, surgical exploration

B. granuloma, surgical exploration

C. granuloma, conservative management

D. serous labyrinthitis, surgical exploration

E. serous labyrinthitis, conservative management.

191. A 50-year-old woman has bilateral sensorineural hearing loss. Her audiogram shows a flat curve. Her hearing is considered to be socially functional if the hearing loss in the speech frequencies is less than:

A. 15 dB

B. 25 dB

C. 30 dB

D. 45 dB

E. 60 dB.

192. A right-handed, 35-year-old woman underwent labyrinthectomy in the left ear for unilateral incapacitating Ménière's disease with no useful auditory function. Compensation for this loss of its impulses takes place in the:

A. ipsilateral vestibular nuclei

B. cerebellum

C. median longitudinal fasciculus

D. reticular formation

E. contralateral labyrinth.

53 193. Patients with Louis-Bar syndrome have symptoms which include ataxia, oculocutaneous telangiectasia, and:

A. situs inversus

B. phenylketonuria

C. sinopulmonary infections

D. sensorineural deafness

E. convulsive disorder.

194. The most frequently encountered malignant tumor of the nose and paranasal sinuses is:

A. adenocarcinoma and adenoid cystic carcinoma

B. squamous cell carcinoma

C. chondrosarcoma and sarcoma

D. mixed tumor

E. none of the above.

195. A 60-year-old male developed convulsions, unconsciousness, chest pain, and hypotension after maxillary sinus irrigation. This suggests the following diagnosis and the first step in therapy is:

A. septicemia, antibiotics

B. cocaine reaction, intravenous diazepam (Valium)

C. air embolism, place patient in the recumber position with the left side down

D. air embolism, place patient in the recumber position with the right side down

E. maxillary artery thrombosis, anticoagulation.

196. Submaxillary calculi can be visualized by x-ray in what percentage of the cases?

A. 10%

B. 25%

C. 50%

54 D. 75%

E. 90%.

197. The most common benign intramural tumor of the esophagus is:

A. angioma

B. fibroma

C. leiomyoma

D. lipoma

E. neurilemmoma.

198. Esophageal perforatio due to passage of a bougie tip is best prevented by:

A. use of antispasmodic drug before dilatation

B. dilatation through an esophagoscope

C. use of general anesthesia

D. use of a swallowed thread as a guide

E. use of lubricant on the dilator.

199. A 40-year-old woman presented with a 1x2 cm nontender, slowly enlarging mass in the infra-auricular area. Should this mass be located in the superficial lobe, the initial surgical treatment would be:

A. enucleation

B. superficial parotidectomy

C. total parotidectomy with preservation of facial nerve

D. total parotidectomy with facial nerve

E. incisional biopsy for permanent section.

200. A 60-year-old male presented with an ulcerating lesion measuring 1.5 cm in diameter in the concha of the left auricle. Examination under the microscope revealed that this lesion barely extended into the cartilaginous canal. Middle ear and mastoid were normal. No neck node was palpated. A biopsy revealed this to be a squamous cell carcinoma. The proper course of management would be:

55 A. preoperative radiation followed by en bloc partial temporal bone resection (leaving the stapes and facial nerve intact) and parotidectomy

B. preoperative radiation followed by partial temporal bone resection (leaving stapes and facial nerve intact)

C. radiation therapy only

D. parotidectomy and partial temporal bone resection (leaving stapes and facial nerve intact)

E. auriculectomy and excision of cartilaginous canal.

201. A 55-year-old healthy male developed a squamous cell carcinoma of the medial wall of the left pyriform sinus, not involving the apex. This lesion also extended to the left lingual surface of the epiglottis. The base of the tongue was determined to be free of tumor. No metastatic node was palpated. The proper course of action would be:

A. radiation therapy for cure

B. preoperative radiation therapy followed by total laryngopharyngectomy

C. preoperative radiation therapy followed by supraglottic laryngopharyngectomy and left radical neck dissection en bloc

D. preoperative radiation followed by total laryngopharyngectomy and left radical neck dissection en bloc

E. supraglottic laryngopharyngectomy and left radical neck dissection en bloc.

202. A 35-year-old male presented with hoarseness for 3 months. He smoked one pack a day for the past 15 years. Indirect laryngoscopy revealed a 3 mm lesion on the left true cord, middle third. The rest of the ENT examination was unremarkable. Direct laryngoscopy and excisional biopsy were done. The pathology report revealed this to be a granular cell myoblastoma and that the margins were not clear of tumor. The proper management would include:

A. close follow-up

B. hemilaryngectomy

C. total laryngectomy

D. reexcisional biopsy with microscopic laryngoscopy

E. cordectomy.

56 203. A 40-year-old healthy male presented with unilateral nasal obstruction. Examination revealed a papillomalike growth in the left nasal fossa. The rest of the ENT examination was unremarkable. Sinus x-rays showed involvement of the left maxillary sinus and erosion of the left nasomaxillary wall. The biopsy was reported as inverting papilloma. The proper course of action should be:

A. intranasal resection of papilloma and Caldwell-Luc procedure

B. lateral rhinotomy and partial maxillectomy

C. lateral rhinotomy, removal of the nasoantral wall, and Caldwell-Luc procedure if necessary

D. maxillectomy

E. partial maxillectomy.

204. A 40-year-old female presented with a pulsatile, nontender, slowly growing mass in the left upper neck. The rest of the ENT and general examination was negative. Carotid angiography shows an "egg-shell" appearing mass displacing the internal carotid artery laterally and widening the bifurcation. The course of action should be:

A. resection of the tumor in total only if it can be done without sacrificing the internal carotid artery

B. resection of the tumor in total even if resection of the internal carotid artery is necessary

C. radiation

D. preoperative radiation and resection of the tumor in total even if the internal carotid artery has to be sacrificed

E. preoperative radiation and resection of the tumor in total only if the internal carotid artery can be spared.

205. The pathognomonic feature of thyroid storm is:

A. fever

B. anxiety

C. tachycardia

D. hypotension

E. hypertension.

57 206. Parathyroid localization studies are indicated:

A. when the surgeon is not very familiar with the anatomy

B. in all patient undergoing neck exploration

C. in patients who had one unsuccessful neck exploration

D. in patients who had several unsuccessul neck explorations

E. none of the above.

207. Total parathyroidectomy and heterotopic autoimplantation is indicated in:

A. renal osteodystrophy in patients not candidates for renal transplantation

B. familial hyperparathyroidism

C. multiple endocrine adenomatosis

D. none of the above

E. all of the above.

208. The origin of the summating potential is the:

A. hair cells

B. stria vascularis

C. auditory nerve

D. supporting cells

E. cochlear nucleus.

209. The generator site for wave V of the ABR is thought to be the:

A. auditory nerve

B. superior olive

C. inferior colliculus

D. hair cells

E. cochlear nucleus.

58 210. The ABR generated by a broad-band click stimulus has its major contribution from which frequency range?

A. 250-500 Hz

B. 500-1000 Hz

C. 1000-2000 Hz

D. 2000-3000 Hz

E. 3000-4000 Hz.

211. A patient has a 60 dB hearing level at 4000 Hz in his suspect ear. To correct the latency of the ABR for this patient, how much should be subtracted?

A. 0.05 msec

B. 0.1 msec

C. 0.2 msec

D. 0.3 msec

E. 0.4 msec.

212. The least interaural latency difference considered suspicious for an acoustic tumor is:

A. 0.1 msec

B. 0.2 msec

C. 0.3 msec

D. 0.4 msec

E. 0.5 msec.

213. The cochlear microphonic originates from the:

A. auditory nerve

B. cochlear nucleus

C. stria vascularis

D. hair cells

59 E. inferior colliculus.

214. The most accurate noninvasive test for acoustic tumor diagnosis is:

A. computerized cranial tomography

B. auditory brain stem responses

C. the crossed acoustic reflex

D. temporal bone polytomography

E. electronystagmography.

215. The normal latency of the fifth wave of the ABR is in the range of:

A. 1-2 msec

B. 2-3 msec

C. 3-4 msec

D. 4-5 msec

E. 5-6 msec.

216. The origin of wave I of the ABR is the:

A. primary auditory projections

B. hair cells

C. inferior colliculus

D. auditory nerve

E. cochlear nucleus.

217. The normal value for the wave III-V interval is approximately:

A. 1 msec

B. 2 msec

C. 3 msec

D. 4 msec

60 E. 5 msec.

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