Abstracts

Rationale: The incidence and timing of status epilepticus (SE) in epilepsy patients has not been well-defined. We performed a cross-sectional retrospective study of SE in epilepsy patients. Methods: We prospectively interviewed 757 epilepsy patients > 5 y.o. seen in the Comprehensive Epilepsy Program. Patients were later contacted to confirm occurrence of SE and acquire details, including date, duration, and type of SE. Kaplan-Meier survival analysis and hazard ratios were used to determine the cumulative frequency of SE during the course of epilepsy. Results: Overall, 20% (157/787) of epilepsy patients reported a history of SE. Cumulative survival distribution plots of epilepsy duration versus first episode of SE revealed a 40% risk of SE after 50 years of epilepsy. The resulting curve had three slopes: the steepest slope occurred in the first two years of epilepsy, and then became intermediate, followed by another steep slope after 40 years of epilepsy. However, too few observations were available after 40 years to be reliable. A likelihood ratio test substantiated that the hazard function was not constant over time (p value < .0001). This method could underestimate the frequency of SE because patients with short duration of epilepsy have not had the opportunity to have SE yet. Therefore, the analysis was repeated using only those patients with at least 10 years of epilepsy and similar results were found. Conclusions: The life-time incidence of SE in our epilepsy population (to 50 years of epilepsy) is approximately 40% among those who persist in having epilepsy. Patients with epilepsy have the greatest increased risk of SE during the first two years of epilepsy, after which the risk per year is constant to 50 years of epilepsy. SE occurs more often in epilepsy than is generally recognized.