CSF analysis in bacterial meningitis typically shows which finding?

CSF analysis in bacterial meningitis typically shows which finding?

• A. Decreased protein
• B. Elevated protein
• C. No cells
• D. Normal protein

Answer: (B)

In bacterial meningitis the CSF shows an inflammatory exudate with high protein. The inflammatory process and damage to the meningeal vessels increase the permeability of the blood–brain barrier, allowing serum proteins to leak into the CSF and promoting local protein production. This makes elevated protein the characteristic finding. Decreased or normal protein would not fit the inflammatory leakage seen in bacterial meningitis, and “no cells” would be inconsistent with the marked pleocytosis typically present (usually neutrophils).

In bacterial meningitis the CSF shows an inflammatory exudate with high protein. The inflammatory process and damage to the meningeal vessels increase the permeability of the blood–brain barrier, allowing serum proteins to leak into the CSF and promoting local protein production. This makes elevated protein the characteristic finding.

Decreased or normal protein would not fit the inflammatory leakage seen in bacterial meningitis, and “no cells” would be inconsistent with the marked pleocytosis typically present (usually neutrophils).