Clinical biochemistry: CSF in Guillain-Barre syndrome: practice question

A Biochemistry 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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Biochemistry · Clinical biochemistry: CSF in Guillain-Barre syndrome

Sample item

A 30-year-old man has ascending symmetric limb weakness and absent reflexes two weeks after an episode of diarrhoea. Which CSF finding is characteristic?

ALow glucose with a neutrophilic pleocytosisBNormal protein with a lymphocytic pleocytosisCXanthochromia with numerous red cellsDRaised protein with a normal cell count

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

The answer and the reasoning

D. Raised protein with a normal cell count

Guillain-Barre syndrome shows albuminocytological dissociation: raised CSF protein from inflamed nerve roots, with few or no cells. The protein may be normal in the first week. A neutrophilic response with low glucose suggests bacterial meningitis.

Option by option

A. Low glucose with a neutrophilic pleocytosis
Low glucose with neutrophils points to bacterial meningitis.
B. Normal protein with a lymphocytic pleocytosis
A lymphocytic pleocytosis with normal protein suggests viral meningitis.
C. Xanthochromia with numerous red cells
Xanthochromia with red cells suggests subarachnoid haemorrhage.
D. Raised protein with a normal cell count (correct)
Correct. High protein with a normal cell count is albuminocytological dissociation.

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 Biochemistry question

What is the answer to this Biochemistry question?

The best answer is D, Raised protein with a normal cell count. Guillain-Barre syndrome shows albuminocytological dissociation: raised CSF protein from inflamed nerve roots, with few or no cells.

Why is "Low glucose with a neutrophilic pleocytosis" not the answer?

Low glucose with neutrophils points to bacterial meningitis.

Why is "Normal protein with a lymphocytic pleocytosis" not the answer?

A lymphocytic pleocytosis with normal protein suggests viral meningitis.

Why is "Xanthochromia with numerous red cells" not the answer?

Xanthochromia with red cells suggests subarachnoid haemorrhage.

What concept does this question test?

It tests Clinical biochemistry: CSF in Guillain-Barre syndrome in Biochemistry. The protein may be normal in the first week. A neutrophilic response with low glucose suggests bacterial meningitis.

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 Clinical biochemistry: CSF in Guillain-Barre syndrome?

Build one table of enzyme deficiency, disease, inheritance and key finding, then revise it by spaced recall. Then use the flashcards and the other Biochemistry 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.