[Partial seizures during the course in patients with absence epilepsy]

We studied the incidence and clinicoelectrographic features of partial seizures in 46 patients with absence epilepsy. Ten patients (21.7%) showed obvious partial seizure symptoms during the course. Five patients had absence attacks with partial seizure symptoms, the ictal EEGs being a generalized 3 Hz spike-wave burst complex preceded by focal discharges. These absence attacks may be partial seizures with secondary bilateral synchronization, which originated from the frontal lobe. Three patients initially had partial seizures related to the frontal lobe, followed by absence attacks 8 months to 2.6 years after the start of CBZ therapy. The appearance of absence attacks may have been triggered by CBZ administration. Two patients had partial seizures at the relapse of epilepsy after the discontinuation of AED therapy for childhood absence epilepsy. This change of seizure types may be associated with the CNS maturation, or with localized cortical hyperexcitability subsequent to the foregoing generalized seizures. The prognosis of absence attacks in the all patients were excellent, and comparable to that of typical absence attacks. Our results suggest that localized cortical areas, especially the frontal lobe, are commonly involved in absence epilepsy. More detailed clinical observation is necessary to understand the pathogenesis of absence epilepsy.