Stroke risk and outcomes in epilepsy patients: Two retrospective cohort studies based on National Health Insurance in Taiwan

Background and aims: The risk of stroke in epileptic patients and the impact of epilepsy history on stroke patients’ outcome have not been studied completely. Our purpose is to evaluate whether patients with epilepsy have increased risk of stroke or post-stroke mortality. Methods: In Study I, we conducted a retrospective cohort study of 6746 patients with newly diagnosed epilepsy and 26,984 persons without epilepsy between 2000 and 2008, in the database of National Health Insurance in Taiwan. The incidences and risks of stroke during the follow-up period were compared between cohorts until the end of 2013. In Study II, we conducted a nested cohort study of 484,990 hospitalized patients with newly diagnosed stroke between 2000 and 2009. We compared the short-term mortality and complications during stroke admission between stroke patients with previous epilepsy and those without epilepsy. Results: The epileptic cohort had an increased stroke risk (hazard ratio [HR] 2.24, 95% CI 2.02 to 2.49). The relationship between epilepsy and stroke risk remains significant in every age group and both sexes. Among hospitalized stroke patients, history of epilepsy was associated with complications, including pneumonia (odds ratio [OR] 1.08, 95% CI 1.00 to 1.18), urinary tract infection (OR 1.16, 95% CI 1.08 to 1.26), and longer stay (p < 0.0001) during the index stroke admission. Conclusions: Epileptic patients face increased stroke risk and adverse outcomes of stroke admission. It is necessary to develop a prevention strategy for stroke in epileptic patients.