Epileptic Syndromes: An Underutilized Concept

The International Classification of Epileptic Seizures (ICES), published in 1970, officially recognized the dichotomy between partial and generalized seizures (1). The subsequent revision (2) narrowed the criteria for classification to clinical and EEG findings only and also allowed for evolution of one seizure type into another. The International Classification of Epileptic Syndromes and Epilepsies was first proposed in 1970 (3). Again the fundamental dichotomy was that between partial and generalized epilepsies. This classification also established a second essential dichotomy between the agerelated idiopathic or cryptogenic epilepsies on the one hand and the symptomatic epilepsies on the other. The 1985 version (4) also adopted the term “localizationrelated” (instead of “partial” or ‘‘focal”) epilepsy and created two new categories: ‘‘epilepsies undetermined as to whether focal or generalized,” and “special syndromes.” The most recent proposal ( 5 ) gave a more precise meaning to the terms “idiopathic,” “symptomatic,’ ’ and ‘ ‘cryptogenic.’ ’ Symptomatic indicates that the epilepsy has a known or suspected etiology. Cryptogenic differs from symptomatic only in that the cause is unclear, so that, stated simply, cryptogenic means “presumed symptomatic.’ ’ Finally, the term idiopathic acquired a clear connotation of an age-related onset and a genetic etiology. Since its publication, the ICES has been well accepted throughout the world. It is applied in clinical research as well as in daily clinical practice and is systematically referred to by general neurologists and epileptologists. By contrast, the International Classification of Epileptic Syndromes and Epilepsies, which was proposed by the same organization, the International League Against Epilepsy (ILAE), and published in the same journal, (Epilepsia), is seldom used in either clinical practice or research.