Which CSF profile is most consistent with viral meningitis?

• A. Low glucose, high protein, neutrophilic pleocytosis
• B. Normal or mildly decreased glucose, normal or mildly increased protein, lymphocytic pleocytosis
• C. Very low glucose, very high protein
• D. High glucose, low protein

Answer: (B)

Viral meningitis typically produces an inflammatory response in the CSF driven mainly by lymphocytes, with only mild changes in glucose and protein. The glucose level is usually normal because viruses don’t consume CSF glucose like bacteria do, and the inflammatory disruption is relatively mild. Protein may be normal or only mildly elevated, reflecting limited meningeal irritation, while the white cell count shows a predominance of lymphocytes rather than neutrophils. This combination—normal or mildly decreased glucose, normal or mildly increased protein, and lymphocytic pleocytosis—fits viral meningitis best. In contrast, bacterial meningitis often has low glucose with a neutrophilic predominance and higher protein, while tuberculous or fungal meningitis tends to show low glucose with very high protein and a more lymphocytic or mixed pleocytosis.