Value of CSF lactate in the differential diagnosis between bacterial meningitis and other diseases with meningeal involvement.

Lactate concentrations in the cerebrospinal fluid of 104 patients were determined by the Monotest Lactate Kit. Lactate values were found higher in cases of bacterial meningitis than in patients not suffering from acute CNS disorders. Elevated lactate levels were also found in patients suffering from aseptic meningitis, septicemia, CNS trauma and cerebrovascular accidents, seizures and diabetes mellitus. The highest levels were found in cases of bacterial meningitis, but there was considerable overlapping between the groups. CSF lactate thus appears to have limited diagnostic value in the differential diagnosis between bacterial meningitis and other diseases with meningeal involvement.