Cerebrospinal fluid gamma-aminobutyric acid levels in children with different types of epilepsy: effect of anticonvulsant treatment.

The mean gamma-aminobutyric acid (GABA) level in lumbar CSF of 31 children with epilepsy was not significantly different from that of 41 age-matched controls. However, when the epileptic children were subdivided into untreated patients and patients treated with antiepileptic drugs, the medication-free subgroup had a significantly lower mean CSF GABA level than nonepileptic children. Patients controlled by anticonvulsant therapy had significantly higher CSF GABA levels than untreated epileptic patients. A more detailed analysis of the children taking antiepileptic medication indicated that the only drug that significantly increased GABA in CSF was valproic acid. Analysis of CSF data with respect to the seizure type of the patients showed that, compared with controls, significantly reduced average GABA levels were present in children with infantile spasms (mostly untreated) and unmedicated generalized tonic-clonic seizures, whereas treated children with generalized tonic-clonic seizures and patients with partial epilepsy (mostly treated) did not significantly differ from controls. The data provide further evidence that impairment of the central GABA system may be involved in human epilepsy.