A 68-year-old man has many months history of progressive hearing loss, unsteady gait, tinnitus, and facial pain. An MRI scan reveals a tumor at the cerebellopontine angle. Which of the following cranial nerves is this tumor most likely to affect?: (A) fourth cranial nerve, (B) sixth cranial nerve, (C) eighth cranial nerve, (D) tenth cranial nerve
Answer is C. An acoustic neuroma is most likely to lead to a palsy of the eighth cranial nerve. Deafness, headache, ataxia, tinnitus, and diplopia are seen, as well as facial paresthesia. Acoustic neuromas represent 5-10% of all intracranial tumors. They develop from Schwann cells and generally grow very slowly. They may be very large before symptoms develop.