The proposals for a revised classification of epilepsy and epileptic syndromes (1981-1985) have again been revised by the Commission on Classification and Terminology of the International League Against Epilepsy.
The proposals for a revised classification of epilepsy and epileptic syndromes (1981-1985) have again been revised by the Commission on Classification and Terminology of the International League Against Epilepsy. The major classes are I. generalized epilepsy, and II. localization related, partial or focal epilepsies. Epilepsies of known etiology (symptomatic or secondary “epilepsies” are separated from idiopathic (primary) and cryptogenic. Idiopathic epilepsies are distinguished from cryptogenic epilepsies. Idiopathic epilepsies are defined by age related onset, clinical and electroencephalographic characteristics and a presumed genetic etiology. Cryptogenic epilepsies are presumed to be symptomatic and the etiology is unknown; they are age related but often do not have well defined electroclinic characteristics. In addition to the localization related and generalized epilepsies and syndromes there are III. unclassified epilepsies, and IV. special syndromes, e.g. febrile convulsions. There are two appendices to the revised classification. 1. Symptomatic generalized epilepsies of specific etiologies including malformations and inborn errors of metabolism and Appendix 2 precipitated seizures, e.g. reflex epilepsies, startle epilepsy, and primary reading epilepsy. [
COMMENT. The Commission recognizes that the revised classification is not totally satisfactory. Patients may move from one syndrome to another during the evolution of the epilepsy, e.g. a child with West syndrome may later satisfy the criteria for the Lennox-Gastaut syndrome. It is of interest that the Commission is reverting to the older traditional concept of an idiopathic "primary" epilepsy of presumed genetic etiology as separate from the cryptogenic epilepsies presumed to be symptomatic. Criticisms of the new classification not stressed by the Commission are as follows: 1) The grouping of seizure patterns proposed are at variance with therapeutic correlations, e.g. absence and tonic-clonic seizures grouped together as generalized epilepsies require different types of medication for their control, and 2) The oversimplification and emphasis of syndromes might lead to a decreased awareness of etiologies and misdiagnoses of underlying pathologies.