Radiotherapy and nuclear medicine basics: Lhermitte sign: practice question

A Radiology 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

Radiology · Radiotherapy and nuclear medicine basics: Lhermitte sign

Sample item

Three months after mantle-field radiotherapy for Hodgkin lymphoma, a patient reports electric-shock sensations down the spine on neck flexion. Examination and MRI are normal, and the symptom settles over several months. What is the cause?

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

The answer and the reasoning

D. Transient radiation myelopathy from demyelination

Lhermitte sign appearing weeks to months after cervical-cord irradiation reflects transient demyelination, resolves spontaneously and does not predict permanent myelopathy. Chronic progressive radiation myelopathy appears after months to years with fixed deficits and cord changes. Recovery with a normal MRI argues against a structural lesion.

Option by option

  • A. Permanent radiation myelitis with cord necrosis

    Permanent myelitis causes progressive fixed deficits and MRI changes.

  • B. Spinal cord metastasis

    A metastasis would produce a visible lesion and progressive deficits.

  • C. Syringomyelia

    A syrinx would be seen on MRI and gives dissociated sensory loss.

  • D. Transient radiation myelopathy from demyelination (correct)

    Correct. Self-limited demyelination causes the transient shock sensations.

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 Radiology questions

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is D, Transient radiation myelopathy from demyelination. Lhermitte sign appearing weeks to months after cervical-cord irradiation reflects transient demyelination, resolves spontaneously and does not predict permanent myelopathy.

Why is "Permanent radiation myelitis with cord necrosis" not the answer?

Permanent myelitis causes progressive fixed deficits and MRI changes.

Why is "Spinal cord metastasis" not the answer?

A metastasis would produce a visible lesion and progressive deficits.

Why is "Syringomyelia" not the answer?

A syrinx would be seen on MRI and gives dissociated sensory loss.

What concept does this question test?

It tests Radiotherapy and nuclear medicine basics: Lhermitte sign in Radiology. Chronic progressive radiation myelopathy appears after months to years with fixed deficits and cord changes. Recovery with a normal MRI argues against a structural lesion.

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 Radiotherapy and nuclear medicine basics: Lhermitte sign?

Learn signs with the image, and the disease they point to. Then use the flashcards and the other Radiology 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.