The concept of hereditary impairment of brain maturation

The classification of benign partial epilepsies and related conditions incl udes (besides rolandic epilepsy) atypical benign partial epilepsy, bioelect rical status epilepticus (ESES) and a variety of other syndromes. The broad overlap of the clinical and bioelectrical symptomatology might reflect a p athogenetic background common to these epilepsies. In order to understand t he great phenotypic variability, the clinical symptomatology in 56 sibships with focal sharp waves of genetic origin was analyzed. A genetic determina tion was assumed if, in addition to the index case, at least one sibling or offspring revealed typical focal sharp waves. The 56 index-cases and their 61 sib/offspring/parents showed a broad spectrum of epileptic and non-epil eptic conditions ranging from mild selective performance deficits to severe complex mental retardation, from neonatal seizures, febrile convulsions, a nd simple rolandic epilepsy to severe epilepsies with minor seizures or ESE S. The different conditions are not disease entities but sets of variably w eighted symptoms of a complex pathogenetic background, in which a genetic d isposition to focal anomalies of brain function is of decisive importance. As can be demonstrated by the data, this genetic liability coincides with o ther widespread genetic traits, expressed in certain EEG patterns, as well as with lesional pathogenetic factors. The biological background of the gen etic focal anomaly is currently unknown. The marked age dependence of the s ymptoms justifies the assumption of an hereditary impairment of brain matur ation.