Neuroanatomy: limbic system: 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: limbic system

Sample item

A 50-year-old man with chronic alcohol use has confusion, ataxia and nystagmus. Weeks later he has severe anterograde amnesia with confabulation. Which structure is characteristically damaged at autopsy?

ANucleus accumbensBAmygdalaCMammillary bodiesDHead of caudate nucleus

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

The answer and the reasoning

C. Mammillary bodies

Thiamine deficiency causes haemorrhagic necrosis of the mammillary bodies and the dorsomedial thalamic nuclei, which are part of the Papez circuit. Wernicke encephalopathy presents with confusion, ophthalmoplegia and ataxia, and untreated cases progress to Korsakoff amnesia. Thiamine must be given before glucose.

Option by option

A. Nucleus accumbens
The nucleus accumbens is part of the reward circuit and is not the site.
B. Amygdala
The amygdala is concerned with emotion and fear and is not the characteristic site.
C. Mammillary bodies (correct)
Correct. Mammillary body damage disrupts the Papez circuit and memory formation.
D. Head of caudate nucleus
The caudate head degenerates in Huntington disease.

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 C, Mammillary bodies. Thiamine deficiency causes haemorrhagic necrosis of the mammillary bodies and the dorsomedial thalamic nuclei, which are part of the Papez circuit.

Why is "Nucleus accumbens" not the answer?

The nucleus accumbens is part of the reward circuit and is not the site.

Why is "Amygdala" not the answer?

The amygdala is concerned with emotion and fear and is not the characteristic site.

Why is "Head of caudate nucleus" not the answer?

The caudate head degenerates in Huntington disease.

What concept does this question test?

It tests Neuroanatomy: limbic system in Anatomy. Wernicke encephalopathy presents with confusion, ophthalmoplegia and ataxia, and untreated cases progress to Korsakoff amnesia. Thiamine must be given before glucose.

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: limbic system?

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.