Cranial Neuropathies Lecture Content

Neurology Maintenance of Certification: Section 9 Cranial Nerve Palsies

Lecture Content: Neuropathies

Olfactory Facial Optic Vestibulocochlear Cranial Neuropathies Oculomotor Glossopharyngeal Maria Baldwin, MD Trochlear Spinal accessory Assistant Professor Trigeminal Hypoglossal Epilepsy, Department of Neurology Abducens Loyola University Medical Center, Maywood, IL [email protected] 2

Question 1: A 27 year old female presents with Question 2: A 37 year old male presents six months of right shoulder weakness. She lost with left facial weakness involving the consciousness 6 months ago and landed on a forehead and lower face and reduced taste radiator pipe, sustaining a burn injury to her right sensation. Loud sounds are bothersome. lateral neck. She can raise her arm to 90 °but no higher. There is unilateral scapular winging with What treatment should be offered? arms abducted. What is the affected muscle or A.A. Aspirin 81 mg daily muscles? B.B. Acyclovir only A.A. Serratus anterior C.C. Acyclovir and prednisone B.B. Trapezius D.D. Prednisone only C.C. Deltoid

3 D.D. Rhomboid 4

Question 3: A 43 year old male presents Question 4: A 73 year old male presents with left-sided weakness and neglect. His with right shoulder droop and weakness of examination is notable for mild right ptosis. head turning, difficulty swallowing, and Eyes are midposition. The right pupil is softening of speech. He reports decreased reduced in diameter compared to the left. taste sensation. There is unilateral palatal What muscle is most likely involved? droop noted on examination. Where is the

A.A. Levator palpebrae most likely site of injury? A.A. Median midbrain B.B. Tarsal (Müller’s muscle) B.B. Rostral pons C.C. Orbicularis oris C.C. Lateral medulla D.D. Superior rectus 5 6 D.D. Jugular foramen

Question 5: A 41 year old Caucasian male presents for acute onset hearing Olfactory Nerve Pathway loss. Examination is notable for bilateral Olfactory bulb keratitis and an ataxic gait. What is the Olfactory receptors most likely diagnosis? located in wall of the nasal cavity A.A. RamsayRamsay--HuntHunt syndrome Penetrate cribiform plate of ethmoid bone -->> B.B. TolosaTolosa--HuntHunt syndrome olfactory bulb C.C. Multiple sclerosis 22ndnd --orderorder neurons course D.D. Cogan’s syndrome posteriorly as the olfactory tract Receptors 7 8 Crossed and uncrossed

Olfactory Nerve (cont.) Olfactory Neuropathies Pathway AnosmiaAnosmia--lacklack of smell Fibers go to Common cold Olfactory tract Most common cause of bilateral Frontal lobe Olfactory bulb transient anosmia Temporal lobe Head trauma •• Terminate in the amygdala Damage to fibers over cribriform nucleus, hypothalamus, plate septal nuclei Back/side impact more damaging than frontal impact Only sensory nerve that Closed head injury can produce avoids the thalamus impairment of recognition despite preserved detection Cortical representation is Neurodegenerative disease bilateral Sensitive as an initial deficit ••Alzheimer’s, Parkinson’s, Unilateral lesions distal to Receptors Huntington’s disease the decussation do not Other 9 10 produce anosmia Cystic fibrosis and adrenal insufficiency

Olfactory Neuropathies Optic Nerve Foster Kennedy syndrome Course Noted with olfactory groove or sphenoid ridge 50 mm long with 4 parts masses Intraocular (nerve head) Commonly seen with meningiomas Intraorbital Ipsilateral anosmia due to direct pressure on the olfactory bulb Intracanalicular Intracranial Ipsilateral optic atrophy due to injury of the ipsilateral optic nerve Optic neuropathies Contralateral papilledema due to raised ICPICP Anterior ischemic optic Do not confuse with….Pseudo Foster Kennedy neuropathy (AION) syndrome Posterior ischemic optic May be noted when increased ICP of any cause occurs in a patient with previous unilateral optic atrophy neuropathy (PION) No anosmia! Optic neuritis Most often due to sequential anterior ischemic optic Leber’s optic neuropathy 11 neuropathy 12

Optic Neuropathy Anterior ischemic optic neuropathy (AION) Optic Neuropathy More likely in those >50>50,, acute onset, minimal pain, limited recovery, altitudinal defect Optic neuritis Unilateral optic disc swelling Demyelinating inflammatory condition 2 types More likely in those <40, subacute onset, NonNon--arteriticarteritic ––MostMost common, painless, acute, altitudinal painful, good recovery Arteritic ––GreaterGreater than 70 years of age •• Usually giant cell arteritis Four subtypes Associated with HTN, DM, OSA, hypercholesterolemia Retrobulbar neuritis: optic nerve Posterior ischemic optic neuropathy (PION) Papillitis: optic disc Similar to AION but ischemia behind the optic disc Do not appreciate optic disc swelling Perineuritis: optic nerve sheath (sparing the nerve) Bilateral PION commonly seen with cardiac and spinal surgeries •• Infection (syphilis) Surgeries greater than 6 hours •• Sarcoid 13 Patients with DM and carotid atherosclerosis 14 Neuroretinitis: swelling of the nerve & macula

Optic Neuritis Clinical features Differential diagnosis Optic Neuritis Vision loss Commonly seen with GradualGradual--occursoccurs hours to inflammatory/autoimmu MRI days ne disease GdE fat saturated T1T1-- Nadir within 11--22 weeks, Multiple sclerosis recovery within 22--44 weighted MRI of the Neuromyelitis optica weeks, 66--1212 months for orbits best sequence nerve to fully heal Syphilis 2/3rds have 20/20 vision GdE shows enhancement Cat scratch disease once recovered in 95% of cases Sarcoidosis Eye pain Rarely occurs in AION Lupus 87% report pain, worse with movement Those without Loss of color vision concomitant brain 88% with abnormal color vision (usually red and green) lesions have a 25% risk Relative APD of MS vs. 72% with 15 Persists in >90% of cases 16 lesions

Optic Neuropathies Oculomotor Nerve

Leber optic neuropathy Function Extraocular muscles Genetic cause of optic neuropathy Superior rectus Point mutation in mitochondrial DNA Medial rectus Adolescent males Inferior rectus Inferior oblique Painless vision loss over weeks to months Levator palpebrae 1. Annulus tendinous 7. Trochlea of S.O. Cardiac anomalies: atrioventricular conduction Constricts the pupil 2. Superior rectus 8. Inferior oblique pathway defects (Wolf--Parkinson(Wolf Parkinson white) Accommodates 3. Inferior rectus 9. Levator palpebrae Converges 4. Medial rectus 10. Eyelid 5. Lateral rectus 11. Eyeball 6. Superior oblique 12. Optic nerve 17 18

Oculomotor Nerve Pathway Oculomotor Neuropathies Exits medial midbrain between midbrain & pons Posterior cerebral artery Categorized by location Runs between the SCA and Nuclear lesions PCA Classic 3 rdrd nerve Then parallel to the posterior Parinaud’s syndrome palsy communicating artery Fascicular lesions Eye is “down & out” Parasympathetic fibers ride CN III Weber Dilated pupil atop the nerve Claude Through cavernous sinus Paralysis of Benedikt accommodation Exits at superior orbital (cycloplegia) fissure Subarachnoid lesions Ptosis Splits into 2 divisions Superior cerebellar Carvernous sinus lesions artery •• Superior division Tolosa Hunt syndrome 19 20 •• Inferior division

Oculomotor Neuropathies Oculomotor Neuropathies Nuclear lesions Causes Fascicular lesions •• Pinealomas Parinaud’s syndrome •• Multiple sclerosis Weber’s syndrome Lesion location •• Stroke Lesion location •• Dorsal midbrain •• Hydrocephalus •• Base of midbrain •• Periaqueductal grey ––VPVP shunt failure •• CNIII Clinical features •• Cortical spinal tracts •• Supranuclear upgaze Dorsal paralysis Clinical features rdrd •• Setting sun sign Periaqueductal grey •• Ipsilateral 3 nerve palsy ––ConjugateConjugate downgaze •• Contralateral hemiplegia in primary position •• Convergence and Lesion Eyelid retraction CNIII fibers 21 ––Collier’sCollier’s sign 22 Spinal tracts Ventral

Oculomotor Neuropathies Oculomotor Neuropathies Red nucleus Fascicular lesions Red nucleus Fascicular lesions Claude syndrome Benedikt syndrome Lesion location Lesion Location •• CNIII •• CNIII •• Red nucleus •• Red nucleus •• Brachium •• Cortical spinal tract conjunctivum Clinical features Clinical symptoms •• Ipsilateral 3rd nerve •• Ipsilateral 3 rdrd nerve palsy palsy •• Contralateral tremor •• Contralateral ataxia •• Contralateral •• Contralateral tremor hemiplegia CNIII fibers Spinal tracts CNIII fibers 23 24

Oculomotor Neuropathies Oculomotor Neuropathies Subarachnoid lesions Cavernous sinus lesions Compressive lesions CN III, CNIV and CNVI Resulting in oculomotor paresis Tumors, aneurysms Fixed and dilated pupil •• Dilated, unresponsive pupil ––AbsenceAbsence of an affected pupil with complete motor Trigeminal nerve VV--1,1, V--2V 2 paresis almost always excludes an aneurysm Sensory loss over •• Posterior communicating aneurysm the most common •• Ophthalmic branch, maxillary aneurysm to cause a CN IIIrd nerve palsy branch Uncal herniation Postganglionic sympathetic fibers •• Hutchinson pupil Wrapped around internal carotid artery •• Pupillary dilatation associated with poor responsresponsee to light but preserved convergence Can result in a Horner’s syndrome •• Ischemic lesions •• Hard to note due to CNIII lesions Pupil sparing Orbital apex syndrome •• Usually resolves in 33--66 months CNII, CNIII, CNIV, CNVI, CNVCNV--11 Diabetes, giant cell arteritis Optic nerve is medial to the cavernous sinus 25 26 Results in cavernous syndrome with visual loss

Trochlear Nerve Oculomotor Neuropathies Function Cavernous sinus lesions Innervates superior oblique muscle Depresses, intorts and abducts the eye TolosaTolosa--HuntHunt syndrome Pathway Clinical Features Nucleus at level of the inferior •• Episodic orbital pain colliculus •• Episodic paralysis of either or all of CN 3, 4, 6 Exits midbrain dorsally & Diagnosis decussates •• Clinical history Runs along undersurface of •• Granuloma seen on MRI or biopsy tentorium •• ESR/CRP elevated Along later wall of cavernous •• CSF normal sinus •• Other causes excluded Enters orbit through superior orbital fissure Treatment Cranial nerve with the longest 27 •• Sensitive to high dose steroids 28 course ((7575 mmmm))

Trochlear Neuropathies Trochlear Neuropathies Incomitant hypertropia Clinical features Congenital palsy Vertical diplopia Most common cause in ••Worse with adduction and children downgaze Decompensation of Head tilting congenital palsy should Hypertropia (elevated eyeeye)) be suspected in all adults ••Occurs on side of the palsied nerve with new onset 4 thth nerve ••Pts unconsciously tilt head away palsy from the palsy ••Worse Head trauma ––WithWith lateral gaze to opposite side Most common acquired ––HeadHead tilt to same side cause (Bielschowsky test) ––DowngazeDowngaze 29 Weakness of down gaze 30

Trigeminal Nerve Trigeminal Nerve Function Pathways Innervates muscles of Sensory bodies in trigeminal mastication ganglion (in petrous bone, lateral Temporalis, masseter, lateral and to cavernous sinus) medial pterygoids, 3 divisions •• Ophthalmic (superior orbital Other muscle groups fissure) Tensor tympani, veli palatini, •• Maxillary (foramen rotundum) myohyoid and anterior belly of the •• Mandibular (foramen ovale) digastric muscles Central processes Sensation of face, eye, nasal and oral •• Synapse within main sensory cavities nucleus Pathways •• Synapse within spinal nucleus ––DescendDescend to different levels of Motor nucleus the pons, medulla or cervical Medial to main sensory nucleus spine Exits foramen ovale Secondary neurons project to VPMVPM-- 31 32 > cortex muscles of mastication

Trigeminal Neuropathies Trigeminal Neuralgia Trigeminal neuralgia (IHS criteria))criteria Basic facts Paroxysmal brief attacks of pain involving one or more divisions of the trigeminal nerve Maxillary branch most commonly affected Pain has at least one characteristic Female>male •• Intense sharp, superficial, stabbing Peak incidence ages 6060--7070 •• Precipitated from trigger zones or trigger factorfactorss Unusual before age 40 Attacks are stereotyped in the individual patient Classical trigeminal neuralgia Etiologies No clinically evident neurological deficit Multiple sclerosis Schwannoma No other disorder to explain symptoms Ectopic loop (SCA, ICA) AV malformation Meningioma Tortuous basilar Symptomatic trigeminal neuralgia Bony deformity Primitive trigeminal artery Causative lesion is found other than a vascular 33 compression 34 CharcotCharcot--MarieMarie--ToothToothSaccular aneurysm

Nucleus Trigeminal Neuralgia Abducens Nerve CNVI Treatments Function Medicines Innervates lateral rectus muscle Carbamazepine ((200200 mg--1200mg 1200 mg/qdmg/qd))--establishedestablished as effective Abducts the eye Oxycarbazepine ((600600 mg--1800mg 1800 mg/qdmg/qd))--probablyprobably Pathway effective Nucleus in lower dorsal Baclofen, lamotriginelamotrigine--possiblypossibly effective pons Topical ophthalmic agentsagents--probablyprobably ineffective Emerges between pons & medulla Surgical options Lateral cavernous sinus Percutaneous procedures on gasserian ganglion Exits out superior orbital •• Gamma knife and microvascular decompression probaprobablblyy 35 effective 36 fissure

Abducens Neuropathies: Congenital Abducens Neuropathies: Non-Congenital MillardMillard--GublerGubler syndrome Duane’s syndrome Mobius syndrome Ipsilateral horizontal gaze palsy (CNVI) Horizontal gaze disturbance Aplasia of one or both CNVI nuclei Ipsilateral facial weakness (CNVII) Bilateral abducens palsies Lateral rectus palsy Contra lateral hemiparesis (cortical spinal tracts) Facial diplegia Some limitation of adduction Can be associated with Foville syndrome Retraction of eyeball into Limb abnormalities socket on adduction Ipsilateral horizontal gaze palsy (CNVI) ChestChest--wallwall abnormalities Poor convergence Crossed eyes Ipsilateral facial weakness Face turns to affected side to Corneal erosions Contra lateral hemiparesis (cortical spinal tracts) compensate for limited movements Contralateral sensory loss Can be associated with other Internuclear ophthalmoplegia ocular, ear and systemic 37 38 malformations Result of AICA infarct commonly

Abducens Neuropathies: Facial Nerve Internuclear Ophthalmoplegia (INO) Function Muscles of facial Anatomy movements Internuclear neurons exit the abducens Other muscles nucleus Stylohyoid muscle, posterior belly of the Cross midline and arise in the MLF digastric, stapedius Terminate in the MR nucleus (dampens sounds) 6 Clinical features Taste Inability to adduct one eye with Anterior 2/3rds of tongue contralateral nystagmus Salivation and lacrimation 7 Parasympathetic Adduction with convergence movements component that innervates are intact lacrimal, submandibular Common causes and sublingual glands Multiple sclerosis Sensation Vascular disorders 40 Posterior surface of the 39 Head trauma external ear and ear canal

Facial Nerve

Motor pathways Nucleus in ventrolateral pons Fibers swing around CNVI Exits lateral caudal pons Sensory pathways Superior salivatory nucleus Reticular formation of lower pons Innervates smooth muscle and glands for lacrimation Tractus solitarius Cell bodies in the geniculate ganglion Taste for anterior 2/3rds tongue

Facial Neuropathies Vestibulocochlear Nerve Blepharospasm Repeated involuntary bilateral contractures of the orbicularis Anatomy oculi muscles Function and pathways Common causes Auditory nerve Idiopathic •• Receives information fro the cochlea (organ for hheaearing)ring) •• Meige syndrome Vestibular nerve ––IdiopathicIdiopathic blepharospasm and oromandibular dystondystoniaia •• Input from the saccular and utricle macules (line(linearar acceleration) ––SustainedSustained grimacing around the mouth, platysma cocontntractionraction •• Cristae of the semicircular canal (angular acceleacceleraration)tion) and sustained neck flexion Multiple sclerosis MultiMulti--systemsystem atrophy Hemifacial spasm Unilateral involuntary hyperactive dysfunction Insidious onset of painless, arrhythmic, tonic or clonic intermittent spasms 45 Lesions near CP angle are the most common cause 46

Vestibulocochlear Neuropathies Vestibulocochlear Neuropathies Neurofibromatosis I Neurofibromatosis II Vertigo ADAD ADAD Subjective sense of movement by the patient that is false Chromosome 17 Chromosome 22 Caused by imbalance of vestibular tone Protein: Neurofibromin Protein: Labyrinth disease Tumors Merlin/Merlin/SchwannominSchwannomin •• Associated with nausea and vomiting usually Plexiform neurofibromas Tumors Ménière's disease Optic gliomas Bilateral vestibular High grade astrocytomas schwannomas Episodic vertigo Other Meningiomas Ependymomas Fluctuating sensorineural hearing loss CaféCafé--auau--laitlait Low frequencies Axillary / inguinal Other Tinnitus freckling Cataracts Usually unilateral Iris hamartomas (Lisch 47 48 nodules)

Glossopharyngeal Nerve Vestibulocochlear Neuropathies Anatomy Shared by CN X also Cogan’s syndrome Function (categorized by nuclei) A chronic inflammatory disease seen mostly in young Solitary nucleus white males Taste and sensation in posterior Symptoms 1/3rd of tongue Bilateral sensorineural hearing loss Carotid body (O 2 sensor) Progressive hearing loss with deafness in 2 years Carotid sinus (baroreceptor Bp) Vestibular symptoms Ménière's like Spinal nucleus of V Inflammatory ocular manifestations (keratitis) Postauricular skin, inner Systemic symptoms tympanic membrane Seen in 30% of patients Mesencephalic nucleus of V Aortic, musculoskeletal complaints Sensory (proprioception ))-- Evaluation stylopharyngeus Ambiguus nucleus Clinical presentationpresentation--imagingimaging often normal MotorMotor--innervatesinnervates stylopharyngeal muscle (elevates pharynx)pharynx) Treatment Inferior salivatory nucleus 49 Corticosteroids 50 Stimulates parotid gland to release saliva

Glossopharyngeal Neuropathy Vagus Nerve Anatomy Glossopharyngeal neuralgia Shared also by CNIX Clinical features Unilateral stabbing, sharp Function (categorize based on nuclei) paroxysmal pain Spinal nucleus of V Abrupt severe pain in the Sensation to external ear, auditory canal and external surface of throat, base of tongue or ear tympanic membrane Triggered by chewing, talking Solitary nucleus •• May be associated with Visceral sensation coughing, excessive salivation, Nucleus ambiguus hoarseness or syncope Motor to striated muscles Peak age 4040--6060 Sensory fibers from below the vocal cords recurrent laryngeal nerve Treatment Dorsal motor nucleus of X Carbamazepine 51 52 Motor to smooth muscles

Vagus Nerve Glossopharyngeal and Vagus Nerve

Recurrent laryngeal nerve Syncope Prone to injury throughout its Syncope may be the only symptom course of metastatic involvement of CNs Aneurysm of the aortic arch, subclavian artery, trachealtracheal-- IX & X bronchial lymph nodes, Accompanies head and neck tumors, thyroidectomy espespafter recurrence Rowland Payne syndrome : “Swallow syncope” assoc with paralysis of the recurrent esophageal CA laryngeal, phrenic, vagal & ••Pts report paroxysmal pain lasting Horners 2’ breast CA seconds to 30 min The left is longer & more

53 likely to be injured 54

Glossopharyngeal and Vagus Spinal Accessory Nerve Lateral medullary syndrome Function ““Wallenberg Syndrome” Motor for Vessel: PICA/Vertebral Artery sternocleidomastoid and Location trapezius muscles Spinothalamic tract Pathway Descending sympathetic tract Accessory Nerve CN IX,X Originates from medulla Vestibular nuclei Vagus nerve and spinal cord (C1(C1--C6)C6) Clinical symptoms Fibers unite and ascend Nystagmus, vertigovertigo,, N/V Enter skull through Ipsilateral loss of pain/temp on foramen magnum face Hypoglossal nerve Exit skull through jugular Contralateral loss of pain./temp over the body foramen Ipsilateral horner’s •• Cranial portion joins the vagus to supply pharynx and larynx Ipsilateral paralysis of palate/vocal cord •• Extra cranial portion supplies the sternocleidomastoid and 55 Diminished gag, hoarseness, dysphagia 56 trapezius

Spinal Accessory Neuropathies Spinal Accessory Neuropathies Jugular foramen syndrome Winged scapula Isolated spinal accessory “Vernet’s syndrome” neuropathy Cranial nerves IX, X, XI pass through Can occur with surgery, line the foramen placement (jugular cannulation), Obstruction leads to lymph node biopsy>tumor ••Ipsilateral trapezius and excision>trauma sternocleidomastoid paresis The trapezius is required to rotate ––WeaknessWeakness turning head away from the scapula in order to elevate lesion and ipsilateral weak shoulder the arm above the horizontal shrug The arm can not be abducted ••Dysphonia with palatal droop above the horizontal ••Dysphagia with absent gag reflex The upper portion of the scapula falls laterally, the inferior angle is ••Loss of taste over posterior 1/3 rdrd of drawn medially, and the vertebral tongue border is flared ••Depressed sensation over posterior This is accentuated on attempted rdrd 57 1/31/3 of tongue, soft palate, uvula, 58 abduction pharynx and larynx

Hypoglossal Nerve Hypoglossal Neuropathy

Function Dejerine’s anterior bulbar syndrome Movements of the tongue Occlusion of anterior spinal artery or its parent Pathways vertebral artery Nucleus runs from 3 clinical features pontinepontine--medullarymedullary Ipsilateral paresis, atrophy and fibrillations of the junction to caudal medulla tongue Rootlets unite and pass •• Protruded tongue deviates toward the lesion through hypoglossal canal Contralateral hemiplegia sparing the face Contralateral loss of position and vibratory sensation (pain and temperature are spared)

60 59

Question 1: A 27 year old female presents with Hypoglossal Neuropathy six months of right shoulder weakness. She lost consciousness 6 months ago and landed on a ColletCollet--SicardSicard syndrome radiator pipe, sustaining a burn injury to her right Lesion damaging hypoglossal nerve and jugular lateral neck. She can raise her arm to 90 °but no foramen higher. There is unilateral scapular winging with 5 clinical features arms abducted. What is the affected muscle or Ipsilateral trapezius and sternocleidomastoid paralysis muscles? Vocal cord and pharynx weakness A.A. Serratus anterior Hemiparalysis of the tongue B.B. Trapezius Loss of taste on posterior 1/3 rdrd of the tongue C.C. Deltoid Hemianesthesia of the palate, pharynx, larynx 61 62 D.D. Rhomboid

Question 2: A 37 year old male presents Question 1: Explanation with left facial weakness involving the B. The trapezius. Scapular forehead and lower face and reduced taste winging is a common questionquestion——andand the long sensation. Loud sounds are bothersome. thoracic nerve/serratus anterior What treatment should be offered? is the common answer. However, this patient sustained lateral neck trauma and cannot A.A. Aspirin 81 mg daily raise the arm greater than 90 °. B.B. Acyclovir only The spinal accessory nerve can be easily injured in the neck C.C. Acyclovir and prednisone due to its superficial course. D.D. Prednisone only The trapezius helps stabilize & rotate the scapula 63 64

Question 3: A 43 year old male presents Question 2: Explanation with left-sided weakness and neglect. His

examination is notable for mild right ptosis. D. The patient Treatment presents with typical N Engl J Med (2007): In patients with Bell’s Eyes are midposition. The right pupil is features of Bell’s palsy, early treatment with prednisolone palsy. Two recent (25mg BID) significantly improves the reduced in diameter compared to the left. chances of recovery at 3 & 9 months. There studies indicated that is no evidence of a benefit of acyclovir in What muscle is most likely involved? prednisone alone is combination with prednisolone. superior to acyclovir Lancet Neurology (2008): Prednisolone A.A. Levator palpebrae (60mg x5d then 10mg x5) shortened the or acyclovir & time to complete recovery in patients with B.B. Tarsal (Müller’s muscle) prednisone. Aspirin is Bell’s, whereas valcyclovir did not affect not indicated facial recovery. C.C. Orbicularis oris D.D. Superior rectus

65 66

Question 4: A 73 year old male presents Question 3: Explanation with right shoulder droop and weakness of ■■ B. The tarsal muscle has sympathetic innervation. It head turning, difficulty swallowing, and contributes mildly to lid softening of speech. He reports decreased elevation (far less than the levator palpebrae innervated taste sensation. There is unilateral palatal by the cranial nerve III). It can be injured anywhere along its droop noted on examination. Where is the path. In this particular case, the mechanism of injury was a most likely site of injury? right carotid dissection. Fibers A.A. Median midbrain that are responsible for eyelid elevation and pupil size reside B.B. Rostral pons on the ICA; fibers responsible for sweating are on the ECA C.C. Lateral medulla

67 68 D.D. Jugular foramen

Question 4: Question 5: A 41 year old Caucasian Explanation male presents for acute onset hearing D. The IX, X and XIth loss. Examination is notable for bilateral cranial nerves run keratitis and an ataxic gait. What is the together through the most likely diagnosis? Jugular Foramen. Glomus jugulare tumors A.A. RamsayRamsay--HuntHunt syndrome and basal skull fractures can injure all three CNs B.B. TolosaTolosa--HuntHunt syndrome at this sitesite C.C. Multiple sclerosis D.D. Cogan’s syndrome

69 70

Question 5: Explanation

D. Cogan’s syndrome is a chronic inflammatory disease. It is common in young Questions & Answers white males Symptoms include Bilateral sensorineural hearing loss (acute onset) The End Progressive hearing loss up to deafness within 2yrs Vestibular symptoms Ménière disease Inflammatory ocular manifestations (non(non--syphiliticsyphilitic

71 interstitial keratitis)