Classification of the epilepsies: New concepts for discussion and debate-Special report of the ILAE Classification Task Force of the Commission for Classification and Terminology

Abstract

The ILAE Task Force on Classification presents a road map for the development of an updated, relevant classification of the epilepsies. Our objective is to explain the process to date and the plan moving forward as well as to invite further discussion about the newly proposed terms and concepts. Here, we present our response to feedback about the 2010 Organization of the Epilepsies and clarify the reintroduction of the word "classification" to map out a framework for epilepsy diagnosis. We introduce some new concepts and suggest four diagnostic levels: seizure type, epilepsy category, epilepsy syndrome, and epilepsy with (specific) etiology to denote specific levels of diagnosis. We expand the etiological categories to six, focusing on those with treatment implications. Finally, we discuss the changes in terminology originally suggested and modifications in response to comments from the epilepsy community. We welcome feedback and discussion from the global epilepsy community, particularly for the new suggested terms, so that we can cement a classification that both reflects current thinking and scientific understanding and provides a dynamic, evolving framework.

Keywords: Classification; Epilepsy syndromes; Etiology; Terminology.

Figure 1

Framework for epilepsy classification. The etiological framework can also be used for acute seizures. The term “genetic” refers to the etiology in an individual if there is an epilepsy syndrome that is known to be primarily genetic based on evidence from family and twin studies. Although the underlying gene may be identified for some individuals, in most cases, the underlying genetic mutation will not be known.