Question:medium
All of the following cranial nerves may be involved in acoustic neuroma, EXCEPT?
All of the following cranial nerves may be involved in acoustic neuroma, EXCEPT?
Show Hint
This tumour sits at the cerebellopontine angle, far from the midbrain nerve controlling eye movement.
Updated On: Jun 24, 2026
- Vagus
- Glossopharyngeal
- Oculomotor
- Facial
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: Locate acoustic neuroma at the cerebellopontine angle, where it sits beside cranial nerves VII and VIII and, with growth, V, IX, X and XI.
Step 2: Early on the eighth nerve gives sensorineural hearing loss and tinnitus; the fifth nerve loss of corneal reflex; the seventh nerve facial sensory and motor signs.
Step 3: Lower cranial nerves IX and X are reached when the tumour is large, producing swallowing and voice problems.
Step 4: The third (oculomotor) nerve runs in the midbrain and cavernous region, well away from the CP angle, so it is not part of acoustic neuroma involvement. Hence the correct EXCEPT answer is oculomotor.
\[\boxed{\text{Oculomotor}}\]
Step 2: Early on the eighth nerve gives sensorineural hearing loss and tinnitus; the fifth nerve loss of corneal reflex; the seventh nerve facial sensory and motor signs.
Step 3: Lower cranial nerves IX and X are reached when the tumour is large, producing swallowing and voice problems.
Step 4: The third (oculomotor) nerve runs in the midbrain and cavernous region, well away from the CP angle, so it is not part of acoustic neuroma involvement. Hence the correct EXCEPT answer is oculomotor.
\[\boxed{\text{Oculomotor}}\]
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