C-reactive protein for rapid monitoring of infections of the central nervous system.

Serum C-reactive protein (CRP) was measured nephelometrically or turbidimetrically for rapid differential diagnosis of sixteen bacterial and fifteen viral infections of the central nervous system in patients aged from 2 weeks to 49 years. On hospital admission CRP levels were far above the upper limit of normal (19 mg/l) in all patients with bacterial meningitis, regardless of the duration of illness, the age of the patient, the bacterium involved, fever, the erythrocyte sedimentation rate, or the cerebrospinal-fluid cell count. In contrast, a slight rise in CRP level was seen in only one case of viral meningitis. CRP was useful also in monitoring the clinical course of the illnesses and in the detection of subdural effusion in one patient with Haemophilus influenzae meningitis and of otitis media in another patient with coxsackie B meningitis. If no complications developed, CRP levels returned to normal within 7 days in the bacterial meningitis group. The rapid measurement of CRP levels is of importance and should be used more often in clinical practice.