Revised terminology and concepts for organization of seizures and epilepsies: Report of the ILAE Commission on Classification and Terminology, 2005–2009

Abstract

SUMMARYThe International League Against Epilepsy (ILAE) Commission on Classification and Terminology has revised concepts, terminology, and approaches for classifying seizures and forms of epilepsy. Generalized and focal are redefined for seizures as occurring in and rapidly engaging bilaterally distributed networks (generalized) and within networks limited to one hemisphere and either discretely localized or more widely distributed (focal). Classification of generalized seizures is simplified. No natural classification for focal seizures exists; focal seizures should be described according to their manifestations (e.g., dyscognitive, focal motor). 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. Not all epilepsies are recognized as electroclinical syndromes. Organization of forms of epilepsy is first by specificity: electroclinical syndromes, nonsyndromic epilepsies with structural-metabolic causes, and epilepsies of unknown cause. Further organization within these divisions can be accomplished in a flexible manner depending on purpose. Natural classes (e.g., specific underlying cause, age at onset, associated seizure type), or pragmatic groupings (e.g., epileptic encephalopathies, self-limited electroclinical syndromes) may serve as the basis for organizing knowledge about recognized forms of epilepsy and facilitate identification of new forms.

Not all that glitters is gold: A guide to critical appraisal of animal drug trials in epilepsy

“…A recent classification of seizures and epilepsies that applies to companion animals, similar to those in humans,58 has been proposed by the International Veterinary Epilepsy Task Force (IVETF) 59. Yet, there is no such classification for experimental animals and there is no agreement on EEG practices and interpretation.…”

Thalamic volume reduction in drug‐naive patients with new‐onset genetic generalized epilepsy

“…People with genetic generalized epilepsy (GGE) are expected to have normal neuroimaging findings when studied with a conventional clinical magnetic resonance imaging (MRI) scan 1, 2. However, subtle abnormalities of brain morphology have frequently been reported.…”

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

“…Such papers address topics that provide a common language or definitions for the international epilepsy community, and the classification of the epilepsies clearly falls within this remit. The Commission for Classification and Terminology 2009–2013 followed the policy and submitted a proposal to refine the 2010 Organization of the Epilepsies3 largely in response to the feedback received over the intervening 3 years. After intense review, a document was submitted to Epilepsia and posted online (Data S1).…”

“…The Berg et al3 report suggested that the term “organization of the epilepsies” be used, rather than “classification of the epilepsies,” to emphasize that the fundamental basis of the epilepsies is not well understood and cannot be scientifically classified, in contrast to many areas of biology. This approach was also designed to promote flexibility in classification so that one could classify according to any domain or property (for example, one could classify by myoclonic seizures, electroencephalogram [EEG] trait, or a host of other features4).…”

“…They may have associated imaging, etiological, prognostic, and treatment implications. Well‐recognized examples include childhood absence epilepsy, juvenile myoclonic epilepsy, and benign epilepsy with centrotemporal spikes 3. The recently released educational ILAE website, epilepsydiagnosis.org, provides an excellent resource to aid in understanding the parameters for diagnosis, to review videos of seizure types, and to assess the EEG features of many established syndromes, and it can be used as a teaching tool around the world by the epilepsy community.…”