A 68-year-old man presents to the clinic for evaluation of progressive hearing loss, ringing in his ears, and facial pain on the left side. The symptoms started 1 month ago. He has also noticed some difficulty with his balance, but reports no falls. Pertinent physical findings are an unsteady gait and decreased hearing in the left ear. His eye movements, facial sensation, and facial movements are normal. An MRI scan of the brain reveals a tumor at the cerebellopontine angle. Which of the following cranial nerves is this tumor most likely to affect?
High-Yield Explanation
A vestibular schwannoma (formerly called 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. Vestibular schwannoma 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.