Case Study 2 (Page 2)

Answer: B, C, D, E.

Examination & Imaging Findings: There is atrophy of the right temporalis (1) and masseter (2) muscles which could be appreciated on the physical examination. There is fluid in the right tympanic bulla (3). The tympanic membrane appeared normal on otoscopic examination. The intracranial mass is not labeled...were you able to identify it? Continue on for more discussion.

Additional History: Cranial nerve examination results:

• menace response: absent OD (+0), likely due to descemetocele / normal OS (+2)
• palpebral reflex: OU (+2)
• corneal sensation: present bilaterally but subjectively slightly decreased OD in comparison to OS

Question: Which one of the following nerves best accounts for the patient's clinical signs?

A) optic nerve (CN II) B) oculomotor nerve (CN III) C) trigeminal nerve (CN V) D) facial nerve (CN VII)

E) vestibulocochlear nerve (CN VIII)

Question: Is the following abnormality an important differential?

Retrobulbar tumor

Yes No

Nerve sheath tumor

Yes No

Olfactory lobe meningioma

Yes No

Lymphosarcoma

Yes No

Toxo or cocci granuloma

Yes No