ILAE classification of the epilepsies: Position paper of the ILAE Commission for Classification and Terminology

The International League Against Epilepsy (ILAE) Classification of the Epilepsies has been updated to reflect our gain in understanding of the epilepsies and their underlying mechanisms following the major scientific advances that have taken place since the last ratified classification in 1989. As a critical tool for the practicing clinician, epilepsy classification must be relevant and dynamic to changes in thinking, yet robust and translatable to all areas of the globe. Its primary purpose is for diagnosis of patients, but it is also critical for epilepsy research, development of antiepileptic therapies, and communication around the world. The new classification originates from a draft document submitted for public comments in 2013, which was revised to incorporate extensive feedback from the international epilepsy community over several rounds of consultation. It presents three levels, starting with seizure type, where it assumes that the patient is having epileptic seizures as defined by the new 2017 ILAE Seizure Classification. After diagnosis of the seizure type, the next step is diagnosis of epilepsy type, including focal epilepsy, generalized epilepsy, combined generalized, and focal epilepsy, and also an unknown epilepsy group. The third level is that of epilepsy syndrome, where a specific syndromic diagnosis can be made. The new classification incorporates etiology along each stage, emphasizing the need to consider etiology at each step of diagnosis, as it often carries significant treatment implications. Etiology is broken into six subgroups, selected because of their potential therapeutic consequences. New terminology is introduced such as developmental and epileptic encephalopathy. The term benign is replaced by the terms self-limited and pharmacoresponsive, to be used where appropriate. It is hoped that this new framework will assist in improving epilepsy care and research in the 21st century.UCB; Eisai; Athena Diagnostics; GlaxoSmithKline; Transgenomics; Biocodex; National Health and Medical Research Council; Australian Research Council; National Institutes of Health (NIH); Human Research Council; Citizens United for Research in Epilepsy (CURE); US Department of Defense; March of Dimes; UCB Pharma; Novartis Pharmaceuticals; Sanofi-Aventis; Novartis; Sage Therapeutics; CIHR (Canadian Institute for Health Research); Alva Foundation; Acorda; Alexza; LCGH; Eisai Medical Research; Lundbeck; Pfizer; SK Life Sciences; Upsher-Smith; Vertex; National Institute of Neurological Disorders and Stroke; Epilepsy Therapy Project; Epilepsy Research Foundation; Epilepsy Study Consortium; Associate Editor of Epilepsia; Bial; Davies/Crandall Chair for Epilepsy Research at UCLA; NIH [NS43209, 1U54NS100064-01, 1-RO1-NS43209]; CURE Infantile Spasms Initiative; US Department of Defense [W81XWH-13-1-0180]; Heffer Family Foundation; Segal Family Foundation; Abbe Goldstein family; Joshua Lurie family; Laurie Marsh family; Dan Levitz family; CURE; Biopharm Solutions; GW Pharma; Mylan; Sanofi; Sun Pharma; Takeda; Stockholm County Council; EU; Electrocore; Sunovion; Epilepsy Research UK; Dravet Syndrome UKSCI(E)ARTICLE4512-5215