Vestibular disorders: VEMP in superior canal dehiscence: practice question

A ENT 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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ENT · Vestibular disorders: VEMP in superior canal dehiscence

Sample item

A woman with sound-induced vertigo is suspected to have superior canal dehiscence. Which VEMP finding supports the diagnosis?

ANormal threshold with delayed latencyBRaised threshold with reduced amplitude on cervical VEMPCAbnormally low threshold with enlarged amplitude on cervical VEMPDAbsent cervical VEMP response bilaterally

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

The answer and the reasoning

C. Abnormally low threshold with enlarged amplitude on cervical VEMP

The dehiscence acts as a third mobile window in the labyrinth, so the vestibular system responds to sound at abnormally low intensities. On VEMP testing this gives a lowered threshold and increased amplitude. High-resolution CT in the plane of the superior canal confirms the dehiscence.

Option by option

A. Normal threshold with delayed latency
A normal threshold with delayed latency suggests a retrolabyrinthine delay rather than a dehiscence.
B. Raised threshold with reduced amplitude on cervical VEMP
A raised threshold with reduced amplitude is typical of a conductive problem such as middle ear disease.
C. Abnormally low threshold with enlarged amplitude on cervical VEMP (correct)
Correct. A third window makes the vestibular response supersensitive, lowering threshold and enlarging amplitude.
D. Absent cervical VEMP response bilaterally
An absent response suggests saccular or inferior vestibular nerve loss, not dehiscence.

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 ENT question

What is the answer to this ENT question?

The best answer is C, Abnormally low threshold with enlarged amplitude on cervical VEMP. The dehiscence acts as a third mobile window in the labyrinth, so the vestibular system responds to sound at abnormally low intensities.

Why is "Normal threshold with delayed latency" not the answer?

A normal threshold with delayed latency suggests a retrolabyrinthine delay rather than a dehiscence.

Why is "Raised threshold with reduced amplitude on cervical VEMP" not the answer?

A raised threshold with reduced amplitude is typical of a conductive problem such as middle ear disease.

Why is "Absent cervical VEMP response bilaterally" not the answer?

An absent response suggests saccular or inferior vestibular nerve loss, not dehiscence.

What concept does this question test?

It tests Vestibular disorders: VEMP in superior canal dehiscence in ENT. On VEMP testing this gives a lowered threshold and increased amplitude. High-resolution CT in the plane of the superior canal confirms the dehiscence.

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 Vestibular disorders: VEMP in superior canal dehiscence?

Learn tuning fork results and audiogram patterns by sketching them. Then use the flashcards and the other ENT 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.