Cerebrospinal fluid/serum lactic acid in febrile convulsions.

Cerebrospinal fluid/serum lactic acid was prospectively assayed in 42 patients with febrile convulsions. Patients were divided into two groups for analytical purposes. Those with brief febrile seizures (30 patients) and the remaining 12 patients had prolonged febrile seizures. CSF and serum lactic acid values were within normal range in patients with brief seizures while elevated values were obtained in patients with prolonged seizures. The mean CSF lactic acid on admission was significantly higher (P less than 0.001) in patients with prolonged seizures than corresponding values in those with brief seizures. Mean serum lactic acid on admission was also significantly higher in patients with prolonged febrile seizures compared to the corresponding mean value in patients with brief seizures (P greater than 0.001). Patients who recovered with neurological deficits had significantly higher CSF lactic acid on admission (P greater than 0.001). Similarly 8 patients who had recurrent febrile convulsions had significantly higher CSF lactate on admission. It is suggested that measurement of CSF lactate can be used as a biochemical marker to identify children with prolonged seizures and those who are likely to have recurrent febrile seizures.