[Continuous spike-wave activity during sleep. Electroencephalographic and clinical features].

Seventeen children were retrospectively evaluated. They exhibited continuous spike-wave activity during slow wave sleep (CSWS). Five of these had only speech problems and seizures (Landau-Kleffner syndrome) (group 1). The other cases had developmental milestones acquisition delay and/or mental retardation (group 2). Epileptic seizures were present in 11 of these, tetraparesis was observed in 5, hemiparesis in 2, microcephaly in 2 and behavior disturbances in 4 cases. The electroencephalogram showed in all cases diffuse CSWS. Group 1 showed diffuse activity, at times accentuated in the centrotemporal region (4/5). Group 2 had widespread discharges, including multifocal activity (5/12), sometimes with anterior predominance (7/12). We concluded that CSWS is a non specific electrographic pattern observed in some types of epilepsy in childhood that have different clinical presentation. It has however some topographic differentiation, depending upon the lesional sites.