Nerve injuries: Wallerian degeneration: practice question

A Orthopaedics 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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Orthopaedics · Nerve injuries: Wallerian degeneration

Sample item

Wallerian degeneration after axonotmesis occurs in which part of the nerve?

AThe cell body onlyBThe axon proximal to the injury onlyCThe axon distal to the site of injuryDThe entire nerve at once, including the epineurium

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

The answer and the reasoning

C. The axon distal to the site of injury

Wallerian degeneration is disintegration of the axon and myelin distal to the lesion, with macrophage clearance and Schwann cell proliferation that forms bands of Bungner guiding regrowth. Proximal changes are limited to a few nodes.

Option by option

A. The cell body only
The cell body shows chromatolysis but this is not Wallerian degeneration.
B. The axon proximal to the injury only
Changes proximally are minimal and limited.
C. The axon distal to the site of injury (correct)
Correct. The axon distal to the lesion degenerates.
D. The entire nerve at once, including the epineurium
The connective tissue sheaths survive in axonotmesis.

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 Orthopaedics question

What is the answer to this Orthopaedics question?

The best answer is C, The axon distal to the site of injury. Wallerian degeneration is disintegration of the axon and myelin distal to the lesion, with macrophage clearance and Schwann cell proliferation that forms bands of Bungner guiding regrowth.

Why is "The cell body only" not the answer?

The cell body shows chromatolysis but this is not Wallerian degeneration.

Why is "The axon proximal to the injury only" not the answer?

Changes proximally are minimal and limited.

Why is "The entire nerve at once, including the epineurium" not the answer?

The connective tissue sheaths survive in axonotmesis.

What concept does this question test?

It tests Nerve injuries: Wallerian degeneration in Orthopaedics. Proximal changes are limited to a few nodes.

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 Nerve injuries: Wallerian degeneration?

Pair each fracture with its classic complication and nerve injured. Then use the flashcards and the other Orthopaedics 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.