Diagnostic use of cerebrospinal fluid lactic acid levels in meningitis.

Analysis of cerebrospinal fluid lactic acid levels in 62 patients suspected of having meningitis was performed. Lactic acid was measured enzymatically using lactic acid dehydrogenase with the liberation of NADH. In a control (no meningitis) group, 46 children had a mean cerebrospinal fluid lactic acid level of 14.7 +/- 2.2 mg/dl; 3 with febrile seizure had a mean lactic acid level of 33.5 +/- 0.98 mg/dl. In 9 cases of bacterial meningitis, the mean lactic acid level was 54.8 +/- 16.8 mg/dl. In 3 patients of aseptic meningitis, the mean lactic acid level was 34.5 +/- 1.0 mg/dl. Serial lactate determination was done in three patients and they were well correlated with the clinical response and other cerebrospinal fluid findings. These data suggest that the determination of cerebrospinal fluid lactic acid may be of diagnostic value in differentiating between bacterial and aseptic meningitis.