Which CSF profile is most consistent with bacterial meningitis?

• A. Normal glucose, elevated protein, lymphocytic predominance
• B. Low glucose, high protein, neutrophilic WBC
• C. High glucose, low protein, eosinophilic WBC
• D. Normal glucose, normal protein, neutrophilic WBC

Answer: (B)

Bacterial meningitis typically causes a rapid inflammatory reaction in the CSF that alters its chemistry and cellular makeup. The bacteria consume glucose and drive inflammatory processes that increase the permeability of the blood–brain barrier, leading to higher protein levels. The inflammatory response also brings neutrophils to the CSF as the first responders in acute bacterial infections. Put together, the classic CSF profile shows low glucose, high protein, and a neutrophil-predominant white blood cell count.

That combination—low CSF glucose, high protein, and neutrophilic WBCs—best fits the pattern expected with bacterial meningitis. By contrast, viral meningitis often presents with normal CSF glucose, only modest protein elevation, and a lymphocyte predominance; eosinophils point to parasitic or certain allergic processes rather than bacterial infection; and normal glucose with normal protein would be inconsistent with an inflammatory bacterial process.