Neuroanatomy: cerebellopontine angle: practice question

A Anatomy question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Anatomy · Neuroanatomy: cerebellopontine angle

Sample item

A 52-year-old woman has progressive hearing loss in the right ear, tinnitus and unsteadiness. MRI shows an enhancing mass in the internal acoustic meatus extending into the cerebellopontine angle. Which additional finding is expected as the tumour enlarges?

AWeak right shoulder shrugBDeviation of the tongue to the rightCLoss of smell on the rightDReduced right corneal sensation

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Reduced right corneal sensation

Vestibular schwannoma arises from the vestibular division of the vestibulocochlear nerve and expands in the cerebellopontine angle. The trigeminal nerve root lies close to the superior part of the angle, so larger tumours reduce corneal sensation first, and later the facial nerve and cerebellum are involved. The accessory and hypoglossal nerves lie lower and the olfactory nerve lies far away.

Option by option

A. Weak right shoulder shrug
The accessory nerve leaves through the jugular foramen and is rarely involved except by very large tumours.
B. Deviation of the tongue to the right
The hypoglossal nerve leaves through the hypoglossal canal low in the medulla and is not involved early.
C. Loss of smell on the right
The olfactory nerve lies in the anterior cranial fossa, far from the angle.
D. Reduced right corneal sensation (correct)
The trigeminal root is compressed by growing tumours, and corneal sensation and the corneal reflex are lost early.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Anatomy question

What is the answer to this Anatomy question?

The best answer is D, Reduced right corneal sensation. Vestibular schwannoma arises from the vestibular division of the vestibulocochlear nerve and expands in the cerebellopontine angle.

Why is "Weak right shoulder shrug" not the answer?

The accessory nerve leaves through the jugular foramen and is rarely involved except by very large tumours.

Why is "Deviation of the tongue to the right" not the answer?

The hypoglossal nerve leaves through the hypoglossal canal low in the medulla and is not involved early.

Why is "Loss of smell on the right" not the answer?

The olfactory nerve lies in the anterior cranial fossa, far from the angle.

What concept does this question test?

It tests Neuroanatomy: cerebellopontine angle in Anatomy. The trigeminal nerve root lies close to the superior part of the angle, so larger tumours reduce corneal sensation first, and later the facial nerve and cerebellum are involved. The accessory and hypoglossal nerves lie lower and the olfactory nerve lies far away.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Neuroanatomy: cerebellopontine angle?

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.