'Normal' CSF in bacterial meningitis.

Cerebrospinal fluid with a normal cell count, glucose and protein values, and a negative Gram's stain smear is usually assumed to exclude the possibility of meningitis. We describe four patients and review from literature 19 patients with pyogenic meningitis in whom the CSF initially appeared normal. Thus, finding minimal or no initial CSF abnormality is consistent with early or developing bacterial meningitis. Repeated lumbar puncture and CSF examination within 24 hours should be considered in all febrile patients in whom the clinical features remain compatible with meningitis.