Neuroanatomy: thalamic pain syndrome: 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: thalamic pain syndrome

Sample item

A 63-year-old man recovering from a right thalamic infarct develops severe burning pain and hypersensitivity on the left half of his body after initial hemisensory loss. The infarct involves the ventral posterolateral nucleus. Which arterial branches supply this nucleus?

AParamedian branches from the first part of the posterior cerebral arteryBThalamogeniculate branches of the posterior cerebral arteryCPolar branches of the posterior communicating arteryDLenticulostriate branches of the middle cerebral artery

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

The answer and the reasoning

B. Thalamogeniculate branches of the posterior cerebral artery

The ventral posterolateral and posteromedial nuclei and the geniculate bodies are supplied by thalamogeniculate branches of the posterior cerebral artery. Infarction here causes the Dejerine-Roussy syndrome: contralateral sensory loss followed by central post-stroke pain.

Option by option

A. Paramedian branches from the first part of the posterior cerebral artery
Paramedian branches supply the medial thalamus and dorsomedial region, causing memory and arousal deficits.
B. Thalamogeniculate branches of the posterior cerebral artery (correct)
Correct. Thalamogeniculate arteries supply the somatosensory relay nuclei of the thalamus.
C. Polar branches of the posterior communicating artery
Polar (tuberothalamic) branches supply the anterior and ventral anterior thalamus.
D. Lenticulostriate branches of the middle cerebral artery
Lenticulostriate branches supply the basal ganglia and internal capsule, not the thalamus.

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 B, Thalamogeniculate branches of the posterior cerebral artery. The ventral posterolateral and posteromedial nuclei and the geniculate bodies are supplied by thalamogeniculate branches of the posterior cerebral artery.

Why is "Paramedian branches from the first part of the posterior cerebral art…" not the answer?

Paramedian branches supply the medial thalamus and dorsomedial region, causing memory and arousal deficits.

Why is "Polar branches of the posterior communicating artery" not the answer?

Polar (tuberothalamic) branches supply the anterior and ventral anterior thalamus.

Why is "Lenticulostriate branches of the middle cerebral artery" not the answer?

Lenticulostriate branches supply the basal ganglia and internal capsule, not the thalamus.

What concept does this question test?

It tests Neuroanatomy: thalamic pain syndrome in Anatomy. Infarction here causes the Dejerine-Roussy syndrome: contralateral sensory loss followed by central post-stroke pain.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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: thalamic pain syndrome?

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.