Applicability of the new ILAE classification for epilepsies (2010) in persons with epilepsy at a tertiary care center in India *Ashwani K. Uttam, †Rupa Joshi, *Rekha Dwivedi, *Kameshwar Prasad, *Madakasira V. Padma, *Rohit Bhatia, *Mamta B. Singh, and *Manjari Tripathi *Department of Neurology, All India Institute of Medical Sciences, New Delhi, India; and †Department of Neuropharmacology, All India Institute of Medical Sciences, New Delhi, India SUMMARY Purpose: To test the applicability of the new International League Against Epilepsy (ILAE) 2010 classification for epilepsies and to compare it with the ILAE 1989 classifica- tion and the ILAE 2001 diagnostic scheme in developing countries with limited resources such as India. Methods: Prospective data of 500 consecutive patients with epilepsy, presenting in neurology department of All India Institute of Medical Sciences, was collected from January 2011 to June 2012 and analyzed according to the three systems proposed by ILAE in 1989, 2001, and 2010. Key Findings: All 500 patients could be classified in the ILAE 1989 classification system, but only 413 in the ILAE 2001 diagnostic scheme (in axes 3 and 4) and 420 in the ILAE 2010 classification system. Leading categories were localization-related epilepsies, symptomatic focal epilep- sies, perinatal insult, and epilepsies attributed to structural and metabolic cause in ILAE 1989, 2001 axis 3, 2001 axis 4, and 2010 systems, respectively. The ILAE 1989 classification system could categorize significantly greater numbers of patients compared to the 2001 and 2010 systems, whereas the latter two remained similar. Significance: A large group of patients remained unclas- sified in the new classification system despite our tre- mendous gain in knowledge through improved imaging, genomics, and molecular biology, and so on, which could be attributed to lack of availability of facilities in devel- oping countries. Dichotomy of localization-related and generalized epilepsy still makes for a fundamental and pragmatic working diagnosis and guides the physician about the extent of investigations and treatment espe- cially in “epilepsies of unknown cause.” KEY WORDS: Epilepsy, Classification, Syndrome, Appli- cability, International League Against Epilepsy, Develop- ing country. Epilepsy is a common condition in neurology comprising a number of electroclinical syndromes and seizure disorders of varying known and unknown etiologies that require variable diagnostic workup, treatment, and obviously have different prognosis. Therefore, for appropriate patient management, the , the best possible classification system for epilepsy is required. The International League Against Epilepsy (ILAE) is continuously working on this. The first ILAE classification for epilepsies published in Epilepsia in 1970 (Merlis, 1970), was characterized by a major dichotomy between generalized and focal epilepsies. It was based on clinical characteristics of each seizure type combined with electroencephalography (EEG) features, etiology, and age at manifestation. The revised ILAE classi- fication introduced another etiologic concept of classifica- tion (as idiopathic and symptomatic) and listed multiple syndromes defined as a cluster of semiologic seizure types, electroencephalography (EEG) patterns etiology, age at onset, and seizure frequency in 1985, followed 4 years later by a modified version with the introduction of the concept of cryptogenic epilepsies, which were presumed to be symp- tomatic, but without definite proof at the current evaluation (Commission on Classification & Terminology of the Inter- national League Against Epilepsy, 1985, 1989). About two decades later, the next system was proposed by the ILAE Task force (Engel, 2001); this was a diagnostic scheme consisting of five axes: axis 1 for semiologic description, axis 2 for seizure type, axis 3 for syndrome, axis 4 for etiology, and axis 5 for disability (optional). Recently the ILAE has proposed a classification that is based on the work of ILAE commission on classification and terminology, 2005–2009 (Berg et al., 2010). The need for a new classification system is emphasized by the com- mission through the fact that the previous ILAE classifica- tions were based on concepts, that for the most part, predated modern neuroimaging, genomic technologies and concepts in molecular biology. The terms “focal” and “generalized” have been used to express a dichotomous Accepted November 27, 2012; Early View publication January 24, 2013. Address correspondence to Manjari Tripathi, Room No. 705, Depart- ment of Neurology, CN Centre, AIIMS, New Delhi 110029, India. E-mail: manjari2tripathi@gmail.com Wiley Periodicals, Inc. © 2013 International League Against Epilepsy 751 Epilepsia, 54(4):751–756, 2013 doi: 10.1111/epi.12086 FULL-LENGTH ORIGINAL RESEARCH