Operational classification of seizure types by theInternational League Against Epilepsy: Position Paper ofthe ILAE Commission for Classification and Terminology

The International League Against Epilepsy (ILAE) presents a revised operational clas-sification of seizure types. The purpose of such a revision is to recognize that some sei-zure types can have either a focal or generalized onset, to allow classification when theonset is unobserved, to include some missing seizure types, and to adopt more trans-parent names. Because current knowledge is insufficient to form a scientifically basedclassification, the 2017 Classification is operational (practical) and based on the 1981Classification, extended in 2010. Changes include the following: (1) “partial” becomes“focal”; (2) awareness is used as a classifier of focal seizures; (3) the terms dyscognitive,simple partial, complex partial, psychic, and secondarily generalized are eliminated;(4) new focal seizure types include automatisms, behavior arrest, hyperkinetic, auto-nomic, cognitive, and emotional; (5) atonic, clonic, epileptic spasms, myoclonic, andtonic seizures can be of either focal or generalized onset; (6) focal to bilateral tonic–clonic seizure replaces secondarily generalized seizure; (7) new generalized seizuretypes are absence with eyelid myoclonia, myoclonic absence, myoclonic–atonic,myoclonic–tonic–clonic; and (8) seizures of unknown onset may have features that canstill be classified. The new classification does not represent a fundamental change, butallows greater flexibility and transparency in naming seizure types.