Myoclonic-astatic epilepsy.

Myoclonic-astatic epilepsy (MAE) belongs to the group of epilepsies with primarily generalized seizures as absence epilepsies, and juvenile myoclonic epilepsy, as well as infantile and juvenile idiopathic epilepsy with generalized tonic-clonic seizures. Like these types of epilepsy, MAE is polygenically determined with little non-genetic variability. The disease is characterized by the following criteria: genetic predisposition (high incidence of seizures and/or genetic EEG patterns in relatives); mostly normal development and no neurological deficits before onset; primarily generalized myoclonic, astatic or myoclonic-astatic seizures, short absences and mostly generalized tonic-clonic seizures; no tonic seizures or tonic drop attacks during daytime (except for some rare cases with a most unfavourable course); generalized EEG patterns (spikes and waves, photosensitivity, 4-7/sec rhythms), no multifocal EEG abnormalities (but often pseudofoci). There is a partial overlap with other 'syndromes', such as benign and severe myoclonic epilepsy in infants (Dravet et al., 1985a, b), myoclonic epilepsy of infancy and early childhood (Aicardi and others). In differential diagnosis the Lennox-Gastaut syndrome in its stricter sense has to be considered, and also atypical benign partial epilepsy or pseudo-Lennox syndrome. Discussion is presented of possible pitfalls in the classical syndromic approach to classifying epilepsies of early childhood, and of the advantages of a neurobiological view for understanding the immense variability of clinical manifestations of epilepsy.