MBB ANATOMY LAB 4: CLNICAL CASES and Cavernous Sinus

Case 1. A man presented to the hospital after being hit in the face by a baseball. He had a black eye with swollen on the right side and complained of tingling sensations over his right cheek and upper lip and on the right side of his nose. On examination, it was apparent that the patient’s right eye was sunk inwards (enophthalmos), and that he suffered from double vision (diplopia) when looking upwards. What is the likely diagnosis?

Case 2. A 27-year-old woman involved in a motorcycle accident was taken to the emergency department of a hospital. She had facial lacerations but no obvious fractures. An eye examination revealed a medial (internal) strabismus of her right eye. What is the likely diagnosis?

Case 3. A ’do-it-yourselfer’ fell from a ladder while replacing a window frame. He sustained a severe blow to his head and was rushed to the emergency department. During the examination, the patient’s level of consciousness gradually decreased. The patient’s right upper was drooping (ptosis), the right eye had become abducted, and its pupil was fixed and dilated. A radiograph revealed that the squamous part of the right temporal bone was fractured. How might this be related to the clinical signs?

Case 4. A 3-day-old female infant was noted to have excessive tearing of the left eye and a small, firm, pea-size mass at the inferior region of the junction between the eye and the nose (oculonasal junction). The mass was not inflamed, and the infant was otherwise in good health and feeding well. What is the likely diagnosis?

The answers to the cases begin on the next page.

1 Clinical Cases

Case 1. A man presented to the hospital after being hit in the face by a baseball. He had a black eye with swollen eyelids on the right side and complained of tingling sensations over his right cheek and upper lip and on the right side of his nose. On examination, it was apparent that the patient’s right eye was sunk inwards (enophthalmos), and that he suffered from double vision (diplopia) when looking upwards. What is the likely diagnosis?

Diagnosis: Blowout fracture of the orbit.

Explanation: This is a classic description of a blowout fracture of the orbit. When the orbital rim is struck by an object of greater circumference, there is an explosive increase in intraorbital pressure. Although the bones comprising the lateral wall and roof of the orbit are usually able to withstand the increased pressure, the thin floor of the orbit is often fractured. In rare instances where the suspensory ligament of the orbit is damaged, the eye may sink into the maxillary sinus (antrum). Should the be trapped in the fractured floor of the orbit, upward movement of the eye is affected and diplopia results. The infraorbital branch of the maxillary nerve is prone to injury because it lies in the floor of the orbit. This nerve supplies an extensive area of skin over the face. Should the nerve be damaged therefore paraesthesia or anaesthesia of the cheek side of the nose and upper lip is expected. A black eye results when blood tracks into the soft tissues around the eye.

Source: Berkovitz BKB, Moxham BJ. A Textbook of Head and Neck Anatomy. London: Yearbook Medical Publishers, Inc. 1988.

Case 2. A 27-year-old woman involved in a motorcycle accident was taken to the emergency department of a hospital. She had facial lacerations but no obvious fractures. An eye examination revealed a medial (internal) strabismus of her right eye. What is the likely diagnosis?

Diagnosis: Sixth nerve palsy

Explanation: Strabismus is a deviation of the eye that a person cannot overcome. In this case, the right abducent nerve was injured, causing paralysis of the right . The patient cannot turn her right eye laterally because when the lateral rectus is paralyzed the medial rectus pulls the eyeball medially (medial strabismus).

Source: Moore KL, Dalley AF. Clinically Oriented Anatomy, 4th ed. Baltimore: Lippincott Williams & Wilkins, 1999, Case 7.15.

Case 3. A ’do-it-yourselfer’ fell from a ladder while replacing a window frame. He sustained a severe blow to his head and was rushed to the emergency department. During the examination, the patient’s level of consciousness gradually decreased. The patient’s right upper eyelid was drooping (ptosis), the right eye had become abducted, and its pupil was fixed and dilated. A radiograph revealed that the squamous part of the right temporal bone was fractured. How might this be related to the clinical signs?

Diagnosis: Extradural hematoma from torn middle meningeal artery

2 Clinical Cases

Explanation: The fracture of the temporal bone was associated with damage to the middle meningeal artery. Extravasated blood had collected between the external periosteal layer of the dura and the calvaria, forming an extradural haematoma. This resulted in an increase in intracranial pressure which was responsible for the decreasing level of consciousness. The symptoms associated with the eye were the consequence of damage to the oculomotor nerve. The ptosis was the result of partial paralysis of the levator palpebrae superioris muscle. The eye was in an abducted position because of the unopposed action of the lateral rectus muscle (supplied by the abducens nerve). Although it ought be expected that the unopposed activity of the (supplied by the trochlear nerve) might cause the eye to be depressed, the muscle acts as a depressor only when the eye is in an adducted position The pupil was fixed and dilated because of interference with the parasympathetic fibers traveling with the oculomotor nerve to the sphincter pupillae and ciliary muscles The fracture of the temporal bone affected the oculomotor nerve because the increased intracranial pressure forced part of the temporal lobe of the brain through the tentorial notch, thereby compressing the oculomotor nerve as it passed through. Malfunction of the oculomotor nerve can also follow from the development of an aneurysm of the left posterior communicating artery. This artery is found at the base of the brain and forms part of the cerebral arterial circle (of Willis). As the oculomotor nerve is closely related to the inferior aspect of the posterior communicating artery, it can be compressed by the enlarging aneurysm.

Source: Berkovitz BKB, Moxham BJ. A Textbook of Head and Neck Anatomy. London: Yearbook Medical Publishers, Inc. 1988.

Case 4. A 3-day-old female infant was noted to have excessive tearing of the left eye and a small, firm, pea-size mass at the inferior region of the junction between the eye and the nose (oculonasal junction). The mass was not inflamed, and the infant was otherwise in good health and feeding well. What is the likely diagnosis?

Diagnosis: atresia

Explanation: The tear drainage system begins at the lacrimal puncta at the medial portion between the upper and lower eyelids. The puncta open into lacrimal canaliculi, which terminate at the , and in turn are drained by the nasolacrimal duct. The nasolacrimal duct develops from a solid cord of cells that recanalizes to establish the lumen of the duct and terminates in the inferior nasal meatus. Atresia of the duct (due to failure to recanalize) occurs in 1 to 3 percent of newborns. Atresia of the lacrimal canaliculi presents with excessive tearing and without a mass. Nasolacrimal duct atresia presents as a mass due to enlargement of the lacrimal sac, and the mass accompanied by excessive tearing suggests atresia of the canaliculi and the nasolacrimal duct. Massage of the nasolacrimal duct region with watchful waiting is the usual treatment, and most cases resolve by age 6 months. Persistent obstruction after age 9 months warrants intervention, such as nasolacrimal duct probing. Care must be exercised to avoid creating a false tract. Because the canaliculi and duct are obstructed in this case, duct probing is indicated.

Source: Cahill DR. Lachman’s Case Studies in Anatomy, 4th Ed. New York, Oxford University Press, 1997.

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