An 8 year old male child comes to the hospital with fever of 3 weeks duration with headache and vomiting. A CSF tap is done, which is suggestive of tubercular meningitis. What is likely to be seen in CSF?

1. A

   Increased TLC with predominance of lymphocytes

2. B

   Increased TLC with predominance of polymorphs

3. C

   Increased glucose levels

4. D

   Decreased in the protein level

Appeared in: RML Lucknow - 2021

Explanation

• In tubercular meningitis (TBM), the cerebrospinal fluid (CSF) characteristically shows pleocytosis, which is an increased number of white blood cells.
• This cellular response is dominated by lymphocytes, reflecting the chronic inflammatory nature of the infection.
• Other classic findings in TBM that support the diagnosis include significantly elevated protein levels and low glucose levels (hypoglycorrhachia).
• The subacute onset of symptoms (3 weeks) is also typical for TBM.

Why Other Options Were Wrong

• Option B: A predominance of polymorphs (neutrophils) in the CSF is the hallmark of acute bacterial (pyogenic) meningitis, not the subacute or chronic inflammation seen in TBM.
• Option C: Tuberculosis bacteria consume glucose in the CSF for metabolism, leading to decreased (hypoglycorrhachia), not increased, glucose levels. A CSF glucose level below 40 mg/dL is typical.
• Option D: The inflammatory process in TBM damages the blood-brain barrier, causing a significant leakage of protein from the blood into the CSF. This results in markedly elevated protein levels, often between 100-500 mg/dL.

Related Visual

Clinical Relevance

• Nursing practice connection: Use the key finding related to Cerebrospinal Fluid (CSF) analysis in Tubercular Meningitis (TBM) to guide bedside assessment, documentation, and the next nursing action.
• Prompt and accurate interpretation of CSF findings is critical for the early diagnosis and initiation of treatment for TBM, which is a neurological emergency.
• Delay in starting anti-tubercular therapy (ATT) and corticosteroids can lead to severe, permanent neurological damage (e.g., blindness, deafness, paralysis) or death.
• What if? If the CSF showed a predominance of polymorphs and very low glucose, the immediate clinical action would be to start broad-spectrum antibiotics for suspected bacterial meningitis, not ATT, while awaiting culture results.

How to Approach the Question

• First, identify the core clinical scenario: a child with symptoms suggestive of meningitis (fever, headache, vomiting) for a subacute duration (3 weeks), with a specific suspected diagnosis of tubercular meningitis (TBM).
• The question asks for the characteristic CSF finding in TBM.
• Recall the classic CSF profiles for different types of meningitis: bacterial (acute, purulent), viral (aseptic), and tuberculous (chronic/subacute).
• For TBM, remember the key features: lymphocytic pleocytosis, high protein, and low glucose.
• Evaluate each option against this classic profile.
• Option A (lymphocytic predominance) matches the TBM profile. Option B (polymorph predominance) points to bacterial meningitis. Options C (high glucose) and D (low protein) are the opposite of what is expected in TBM.

Concept Tested & Keywords

• Concept Tested: Cerebrospinal Fluid (CSF) analysis in Tubercular Meningitis (TBM)
• Stem keywords: 8 year old, fever, headache, vomiting, tubercular meningitis, CSF
• Lead-in keywords: What is likely to be seen
• Clinical cues: The 3-week duration of symptoms points towards a subacute or chronic process like tuberculosis, rather than an acute bacterial or viral infection.

Question ID

QlEz__te9RwoU5XgpRcTfD

Copy ID

Reference Book

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 1848-1850

E6 Medicine Harrison 22e Part 1 p. 1168-1170