Classifications of Epileptic Syndromes: Advantages and Limitations for Evaluation of Childhood Epileptic Syndromes in Clinical Practice

Abstract

The advantages and limitations of the two most recent International League Against Epilepsy classifications of the epilepsies and epileptic syndromes have been assessed after examining the clinical records of 645 consecutive outpatients aged 1 months to 15 years followed at the Children''s Epilepsy Center of the University of Milan, Italy, from 1977 through 1985. The percentage of cases that could be classified according to the 1970 and 1985 proposals for classification were 94.1 and 98.1%, respectively. According to the 1985 proposal, partial epilepsies (PE) and generalized epilepsies (GE) were almost equally represented (45.0 vs. 47.2%). Among PE, symptomatic epilepsies were the commonest variety. In the group of GE, idiopathic and/or symptomatic epilepsies were most common. Childhood absence epilepsy was the largest subgroup among idiopathic GE. Newly diagnosed patients, a less biased sample of the epileptic population represented 38.9% of the entire sample, and a proper classification was possible in 96% of cases. Idiopathic epilepsies were about twice as frequent and idiopathic and/or symptomatic GE less frequent in newly diagnosed patients when compared with the remainder. Marked differences in the frequency of the epilepsies were found in comparison with other reports in the literature which used the 1970 classification. This finding probably depends on different diagnostic assessment, selection bias, and different geographic and ethnic components, but it can also reflect the variable interporetation of the clinical and EEG features of a patient with epilepsy in the light of the artifactual categories of the classification.