Neurology: locked-in syndrome: practice question

A General Medicine 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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General Medicine · Neurology: locked-in syndrome

Sample item

A 55-year-old man with sudden quadriplegia and inability to speak is fully alert. He answers questions by blinking and moving his eyes up and down. Which lesion explains this?

ABilateral infarction of the cerebral hemispheresBInfarction of the midbrain tegmentumCHaemorrhage in the thalamusDInfarction of the ventral pons from basilar artery occlusion

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

The answer and the reasoning

D. Infarction of the ventral pons from basilar artery occlusion

Locked-in syndrome results from a ventral pontine lesion, usually basilar artery occlusion. Corticospinal and corticobulbar fibres are interrupted, causing quadriplegia and loss of speech and horizontal gaze, but the reticular activating system is spared. Vertical eye movements and blinking are preserved because they are controlled by the midbrain.

Option by option

A. Bilateral infarction of the cerebral hemispheres
Bilateral hemispheric damage would impair consciousness or cognition and preserve horizontal eye movements.
B. Infarction of the midbrain tegmentum
Midbrain tegmental damage typically causes coma or oculomotor palsies.
C. Haemorrhage in the thalamus
A thalamic haemorrhage gives sensory loss and altered consciousness, not quadriplegia with preserved awareness.
D. Infarction of the ventral pons from basilar artery occlusion (correct)
Correct. A ventral pontine infarct leaves awareness and vertical eye movements intact.

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 General Medicine question

What is the answer to this General Medicine question?

The best answer is D, Infarction of the ventral pons from basilar artery occlusion. Locked-in syndrome results from a ventral pontine lesion, usually basilar artery occlusion.

Why is "Bilateral infarction of the cerebral hemispheres" not the answer?

Bilateral hemispheric damage would impair consciousness or cognition and preserve horizontal eye movements.

Why is "Infarction of the midbrain tegmentum" not the answer?

Midbrain tegmental damage typically causes coma or oculomotor palsies.

Why is "Haemorrhage in the thalamus" not the answer?

A thalamic haemorrhage gives sensory loss and altered consciousness, not quadriplegia with preserved awareness.

What concept does this question test?

It tests Neurology: locked-in syndrome in General Medicine. Corticospinal and corticobulbar fibres are interrupted, causing quadriplegia and loss of speech and horizontal gaze, but the reticular activating system is spared. Vertical eye movements and blinking are preserved because they are controlled by the midbrain.

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 Neurology: locked-in syndrome?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine 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.