[Aggravation of epilepsy by valproate sodium in a child with cryptogenic localization-related epilepsy]

We report a paradoxical effect of valproate sodium (VPA) observed in a 3-year-old girl with cryptogenic localization-related epilepsy. On admission she experienced two types of seizures that were confirmed by ictal EEGs : complex partial seizures (CPSs) originating from the left hemisphere and combined seizures that began with repetitive myoclonic seizures immediately followed by a CPS. These myoclonic seizures did not possess asymmetrical features, but the ictal EEGs showed left-side dominant multiple spike-waves. The patent's interictal EEGs on admission showed left posterior temporal- parietal spikes during wakefulness and frequent diffuse spike-waves during sleep. In the process of introduction and increase in the dosage of VPA, an aggravation of epileptic discharges, especially a dramatic increase in diffuse spike-waves during sleep, was observed. In the same period of time, myoclonic seizures not followed by CPS newly appeared, and there was an increase in the frequency of CPSs and combined seizures. Marked improvement of epileptic discharges, namely the disappearance of diffuse discharges, and complete suppression of all types of seizures were achieved by the introduction of carbamazepine (CBZ) along with the withdrawal of VPA. During the clinical course, the patient did not display any signs or symptoms of VPA encephalitis, overdose of VPA or metabolic aberration. The paradoxical effect of CBZ in localization-related epilepsy is well-known, yet in this case, VPA displayed a similar paradoxical effect. Additionally, CBZ was efficacious in the suppression of secondary bilateral synchrony on EEG and also successfully controlled CPSs, combined seizures and myoclonic seizures.