Question

Assertion (A): Lumbar puncture is indicated in a child with fever and asymmetric flaccid limb weakness.

Reason (R): The diagnosis of Guillain-Barre syndrome can be established by albuminocytologic dissociation on CSF analysis.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is NOT the correct explanation of A.
• C. A is true but R is false.
• D. A is false but R is true.

Hint:

GBS is usually symmetric and afebrile; fever with asymmetric weakness points elsewhere.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
A child with fever and asymmetric flaccid limb weakness has acute flaccid paralysis, and we need to work out both whether lumbar puncture is indicated and whether the reason given about Guillain-Barre syndrome is what actually justifies it here.

Step 2: Key Concept:
Acute flaccid paralysis in a child has several possible causes, including poliomyelitis, Guillain-Barre syndrome (GBS), transverse myelitis and infective meningoencephalitis. Because fever points toward an infective or inflammatory cause and the differential includes conditions like poliomyelitis and meningitis, a lumbar puncture with CSF study is a standard and necessary step to help identify the cause and rule out infection of the central nervous system. GBS, in contrast, classically causes symmetric ascending weakness and is usually not associated with fever, and its typical CSF finding of albuminocytologic dissociation, raised protein with a near normal cell count, usually appears only after the first week of illness.

Step 3: Detailed Explanation:
Assertion (A) is true: a febrile child with flaccid weakness genuinely needs a lumbar puncture, mainly to look for an infective process such as poliovirus involvement or meningoencephalitis, and to characterize the CSF pattern.
Reason (R) is also true as a general fact: albuminocytologic dissociation on CSF analysis is indeed the classic finding used to support a diagnosis of GBS.
However, the clinical picture described, fever with asymmetric weakness, is not the typical picture of GBS, which is usually afebrile and symmetric. So the reason, while a true fact about GBS, is not the actual justification for doing the lumbar puncture in this particular case; the LP here is indicated to search for an infective cause of asymmetric flaccid paralysis, not to confirm GBS.

Step 4: Final Answer:
Both statements are true, but R is not the correct explanation of A.