Neuroanatomy: cerebellar vermis: 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: cerebellar vermis

Sample item

A 5-year-old child has morning vomiting and a wide-based gait with a tendency to fall backwards. Finger-to-nose testing is normal. MRI shows a midline mass arising from the roof of the fourth ventricle. Which part of the cerebellum is primarily affected?

ALateral part of a cerebellar hemisphereBDentate nucleusCSuperior cerebellar peduncleDVermis

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

The answer and the reasoning

D. Vermis

The vermis and flocculonodular region control axial and truncal posture and gait. A midline tumour such as medulloblastoma damages the vermis and causes truncal ataxia with relative sparing of limb coordination, and may obstruct the fourth ventricle, causing hydrocephalus. Hemispheric lesions cause ipsilateral limb ataxia.

Option by option

A. Lateral part of a cerebellar hemisphere
A lateral hemispheric lesion causes ipsilateral limb dysmetria and intention tremor.
B. Dentate nucleus
The dentate nucleus carries cerebellar output for limb coordination, and its damage gives limb ataxia.
C. Superior cerebellar peduncle
The superior peduncle is the main output pathway and its damage causes ipsilateral limb ataxia and tremor.
D. Vermis (correct)
Vermian damage causes truncal ataxia and wide-based gait with normal limb tests.

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, Vermis. The vermis and flocculonodular region control axial and truncal posture and gait.

Why is "Lateral part of a cerebellar hemisphere" not the answer?

A lateral hemispheric lesion causes ipsilateral limb dysmetria and intention tremor.

Why is "Dentate nucleus" not the answer?

The dentate nucleus carries cerebellar output for limb coordination, and its damage gives limb ataxia.

Why is "Superior cerebellar peduncle" not the answer?

The superior peduncle is the main output pathway and its damage causes ipsilateral limb ataxia and tremor.

What concept does this question test?

It tests Neuroanatomy: cerebellar vermis in Anatomy. A midline tumour such as medulloblastoma damages the vermis and causes truncal ataxia with relative sparing of limb coordination, and may obstruct the fourth ventricle, causing hydrocephalus. Hemispheric lesions cause ipsilateral limb ataxia.

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: cerebellar vermis?

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.