Classification of epilepsies and epileptic syndromes of childhood according to the 1989 ILAE classification

Abstract

We attempted to classify, according to the 1989 International Classification of Epilepsies and Epileptic Syndromes, 255 children under 6 years of age consecutively examined for 1 year in an outpatient clinic of child neurology of the university hospital. All the patients were classified as follows: 57 (22.4%) localization-related epilepsies (37 symptomatic and 20 cryptogenic cases), 55 (21.6%) generalized epilepsies (7 idiopathic, 46 symptomatic cases, and 2 cryptogenic), 33 (12.9%) undetermined epilepsies, and 110 (43.1%) special syndromes (103 with febrile convulsions and 7 others). The fact that a substantial proportion of the patients lacked specific clinical or EEG features suggesting individual epileptic syndromes made subclassification of symptomatic and cryptogenic localization-related epilepsies sometimes difficult. The boundary of cryptogenic cases was considered to be somewhat arbitrary because it was somewhat dependent on the extent of the diagnostic examinations. Further elucidation of new epileptic syndromes in symptomatic generalized epilepsies is necessary because 14 cases (30.4%) of 46 symptomatic generalized epilepsies were classified as “other symptomatic epilepsies”.