Abstracts

Seizure outcomes are usually studied at one point in time and assumed to be static. Increasing evidence indicates this is not the case., In a prospective study of 613 children with epilepsy newly diagnosed in 1993-97, patterns of remission, relapse, and poor outcome were characterized in those children with idiopathic/cryptogenic (I/C) epilepsy and followed [underline][gt][/underline]8y. Syndromes were grouped as idiopathic localization-related (ILRE), cryptogenic focal (CFE), idiopathic generalized (IGE), and undetermined (UND). The minimum time seizure-free to be considered a remission was 1y, and remission of [underline][gt][/underline]5y was considered a good outcome., 437 children had I/C epilepsy of whom 393 (90%) were followed [underline][gt][/underline]8 y (max 13y). The best possible outcome, no seizures since diagnosis, occurred in 69 (18%) and the worst, failure of 2 AEDs and never achieved 5y seizure-free at any time, occurred in 36 (9%). An additional 148 (38%) were at least 5y seizure-free at last contact after having seizures during the first one (N=99) through several years (N=49) after initial diagnosis. Another 63 (16%) had episodes of repeated brief remissions (1-2 years long) with relapses but are now [underline][gt][/underline]5y seizure-free. Finally 24 (6%) had achieved a 5y remission at some point but then relapsed, and 59 (15%) had achieved multiple briefer (1-3y) periods of remission with repeated relapse but were never 5y seizure-free. Syndrome group was strongly associated with the seizure outcome pattern (p[lt]0.0001). Most of the effect was due to the ILRE group having much better outcomes than the other three groups which were generally indistinguishable from each other. The IGE group, however, was significantly less likely to have the best outcome than any of each of the other three groups (all p=[lt]0.01). In a total of 616 [underline][gt][/underline]1year remission periods experienced by the 393 children, 272 remission periods ended in a relapse: 35% without any apparent provocation, 12% in association with noncompliance, 6% during tapering of AEDs, 33% after all AEDs were stopped, 3% in association with illness, and 11% in other settings., Although most children with I/C epilepsy achieve prolonged periods seizure-free, seizure outcome patterns over many years are complex and dynamic. A simple characterization at one point in time may not be the most informative approach for studying determinates of seizure outcome or for studying the effects of seizures on social, educational, and other endpoints of interest in young people with epilepsy., (Supported by NIH NINDS-RO1-NS31146.)