Neuroanatomy: border-zone infarction: 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.

Try it

Anatomy · Neuroanatomy: border-zone infarction

Sample item

A 60-year-old man has profound hypotension during a cardiac arrest and resuscitation. Afterwards he has bilateral weakness of the shoulders and proximal arms with relatively preserved hand strength and normal facial movement. Which region is infarcted?

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

The answer and the reasoning

D. ACA-MCA border zone cortex

Border-zone (watershed) infarcts lie where the distal territories of two arteries meet and are the most vulnerable in global hypoperfusion. The parasagittal zone between the anterior and middle cerebral arteries contains the cortex for the shoulders and proximal arms, so bilateral proximal arm weakness results.

Option by option

  • A. Cervical anterior horn cells

    Cord watershed injury favours the mid-thoracic segments and would affect the legs rather than the arms.

  • B. Bilateral basal pons

    A bilateral basal pontine infarct causes quadriplegia with facial and bulbar involvement.

  • C. Both posterior internal capsule limbs

    Capsular infarcts follow penetrating artery occlusion, not global hypotension, and would also weaken the face and legs.

  • D. ACA-MCA border zone cortex (correct)

    Correct. Global hypoperfusion injures the ACA-MCA watershed, which holds the proximal arm representation.

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.

More Anatomy questions

Questions about this Anatomy question

What is the answer to this Anatomy question?

The best answer is D, ACA-MCA border zone cortex. Border-zone (watershed) infarcts lie where the distal territories of two arteries meet and are the most vulnerable in global hypoperfusion.

Why is "Cervical anterior horn cells" not the answer?

Cord watershed injury favours the mid-thoracic segments and would affect the legs rather than the arms.

Why is "Bilateral basal pons" not the answer?

A bilateral basal pontine infarct causes quadriplegia with facial and bulbar involvement.

Why is "Both posterior internal capsule limbs" not the answer?

Capsular infarcts follow penetrating artery occlusion, not global hypotension, and would also weaken the face and legs.

What concept does this question test?

It tests Neuroanatomy: border-zone infarction in Anatomy. The parasagittal zone between the anterior and middle cerebral arteries contains the cortex for the shoulders and proximal arms, so bilateral proximal arm weakness results.

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: border-zone infarction?

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.