Neuroimaging: neuronal migration disorder: 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.

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Radiology · Neuroimaging: neuronal migration disorder

Sample item

An infant with developmental delay and seizures has an MRI showing a smooth brain surface with absent sulci and a thick cortex. What is the diagnosis?

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

The answer and the reasoning

A. Lissencephaly

Lissencephaly, or smooth brain, is a neuronal migration disorder with absent gyri, thick cortex and shallow Sylvian fissures, presenting with seizures and delay. Holoprosencephaly shows failure of hemispheric separation, and hydranencephaly shows loss of hemispheres replaced by CSF. Dandy-Walker involves the posterior fossa.

Option by option

  • A. Lissencephaly (correct)

    Correct. Absent sulci with a thick cortex is lissencephaly.

  • B. Hydranencephaly

    Hydranencephaly shows a CSF-filled cranium with absent cortex.

  • C. Dandy-Walker malformation

    Dandy-Walker malformation shows a cystic posterior fossa with an absent vermis.

  • D. Holoprosencephaly

    Holoprosencephaly shows a single ventricle and fused hemispheres.

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 A, Lissencephaly. Lissencephaly, or smooth brain, is a neuronal migration disorder with absent gyri, thick cortex and shallow Sylvian fissures, presenting with seizures and delay.

Why is "Hydranencephaly" not the answer?

Hydranencephaly shows a CSF-filled cranium with absent cortex.

Why is "Dandy-Walker malformation" not the answer?

Dandy-Walker malformation shows a cystic posterior fossa with an absent vermis.

Why is "Holoprosencephaly" not the answer?

Holoprosencephaly shows a single ventricle and fused hemispheres.

What concept does this question test?

It tests Neuroimaging: neuronal migration disorder in Radiology. Holoprosencephaly shows failure of hemispheric separation, and hydranencephaly shows loss of hemispheres replaced by CSF. Dandy-Walker involves the posterior fossa.

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 Neuroimaging: neuronal migration disorder?

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.