Vestibular disorders: caloric test in coma: 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: caloric test in coma

Sample item

Ice-cold water is irrigated into the right ear of an unconscious patient with an intact brainstem. What eye response is expected?

ANystagmus with its fast phase toward the leftBNystagmus with its fast phase toward the rightCTonic deviation of the eyes toward the right with no fast phaseDNo eye movement at all

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

The answer and the reasoning

C. Tonic deviation of the eyes toward the right with no fast phase

In an awake person cold water gives nystagmus with a fast phase away from the irrigated ear (COWS). The fast phase is a cortical corrective movement, so in coma it is absent and only the slow vestibular drive remains, producing sustained conjugate deviation toward the cold-irrigated ear. Absent deviation indicates brainstem dysfunction.

Option by option

A. Nystagmus with its fast phase toward the left
A fast phase away from the cold ear needs cortical function and is lost in coma.
B. Nystagmus with its fast phase toward the right
A fast phase toward the cold ear is the opposite of the awake response and does not occur.
C. Tonic deviation of the eyes toward the right with no fast phase (correct)
Correct. Without cortical input only the slow phase appears, so the eyes deviate tonically toward the irrigated ear.
D. No eye movement at all
Absence of any movement would suggest a brainstem lesion, not an intact brainstem.

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, Tonic deviation of the eyes toward the right with no fast phase. In an awake person cold water gives nystagmus with a fast phase away from the irrigated ear (COWS).

Why is "Nystagmus with its fast phase toward the left" not the answer?

A fast phase away from the cold ear needs cortical function and is lost in coma.

Why is "Nystagmus with its fast phase toward the right" not the answer?

A fast phase toward the cold ear is the opposite of the awake response and does not occur.

Why is "No eye movement at all" not the answer?

Absence of any movement would suggest a brainstem lesion, not an intact brainstem.

What concept does this question test?

It tests Vestibular disorders: caloric test in coma in ENT. The fast phase is a cortical corrective movement, so in coma it is absent and only the slow vestibular drive remains, producing sustained conjugate deviation toward the cold-irrigated ear. Absent deviation indicates brainstem dysfunction.

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: caloric test in coma?

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.