The International League Against Epilepsy (ILAE) Commission on Classification and Terminology has revised concepts, terminology, and approaches for classifying seizures and forms of epilepsy, last updated in 1981 for seizures and in 1989 for epilepsies. Changes in the 1981 classification for seizures include the following: 1) Neonatal seizures are not a separate entity and are included under “electroclinical syndromes arranged by age at onset”; 2) Spasms are now recognized as “epileptic spasms,” which includes infantile spasms; 3) Focal simple partial and complex partial categories of focal seizures are eliminated and replaced by focal “without impairment of consciousness or awareness” and “with impairment of consciousness or awareness;” 4) Focal seizure “evolving to a bilateral convulsive seizure” replaces the term “secondarily generalized seizure;” and 5) “Myoclonic atonic” replaces “myoclonic astatic” seizures. The new seizure classification has 3 main categories: generalized (tonic-clonic, absence, myoclonic, clonic, tonic, atonic), focal, and unknown. The new classification of electroclinical syndromes and other epilepsies is grouped according to 1) age at onset (neonatal period, infancy, childhood, and adolescent-adult), 2) as distinctive “constellations,” (mesial temporal lobe epilepsy, Rasmussen syndrome, gelastic seizures, hemiconvulsion-hemiplegia-epilepsy); epilepsies attributed to “structural-metabolic” causes, to angioma, of unknown cause, and seizures not recognized as epilepsies (benign neonatal seizures and febrile seizures). The concepts of generalized and focal do not apply to electroclinical syndromes. Genetic, structural-metabolic, and unknown represent modified concepts to replace idiopathic, symptomatic, and cryptogenic. 
COMMENT. As one of the last Fellows privileged to have known and worked under Doctor William Gordon Lennox at his Seizure Unit, Children's Medical Center, Boston, in 1953-1954, I am sure he would have applauded the attempts to reclassify seizures and advance our understanding of the epilepsies. In keeping with some of the editorial comments regarding the new classification , Dr Lennox might have questioned the need to replace the terms idiopathic, symptomatic, and cryptogenic. As intended, the ILAE Commission has provided a basis and guide for further epidemiological studies. In the last half century, I have witnessed many changes in the classification of seizures since the simple triad of grand mal, petit mal, and psychomotor, genetic or acquired, metabolic or organic (structural). In the use of the term structural-metabolic in the new classification we have partially reverted to the Lennox terminology. (Epilepsy and Related Disorders. Vol 1. Boston; Little, Brown and Company, 1960).