The etiology of epilepsy is a major determinant of clinical course and prognosis, yet the current classifications of epilepsy do not list etiology in any detail. In this article, a classification (database) of the etiologies of epilepsy is proposed. In this scheme, the etiology of epilepsy is divided into four categories: idiopathic, symptomatic, provoked, and cryptogenic. These are defined and subcategories are proposed. A commentary addressing the following points is included: problems associated with assigning causation, symptomatic versus idiopathic epilepsy, focal versus generalized epilepsy, acquired epilepsy, acute symptomatic epilepsy, risk factor analysis, provoked epilepsy genetic and developmental epilepsy, and epilepsy as a disease not a symptom. Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.
