Association of the timing and type of acute symptomatic seizures with post-stroke epilepsy and mortality

BackgroundAcute symptomatic seizures (ASyS) increase the risk of epilepsy and mortality after a stroke. The impact of the timing and type of ASyS remains unclear. MethodsThis multicenter cohort study included data from nine centers between 2002 and 2018, with final analysis in February 2024. The study included 4,552 adults (2,005 female; median age 73 years) with ischemic stroke and no seizure history. We examined ASyS occurring within seven days after stroke. Main outcomes were all-cause mortality and epilepsy. Validation in three separate cohorts included 74 adults with ASyS. ResultsThe ten-year risk of post-stroke epilepsy ranged from 41% to 94%, and mortality from 36% to 100%, depending on ASyS type and timing. ASyS on stroke onset day had a higher epilepsy risk (aHR 2.3, 95% CI 1.3-4.0, p=0.003) compared to later ASyS. Status epilepticus had the highest epilepsy risk (aHR 9.6, 95% CI 3.5-26.7, p<0.001), followed by focal to bilateral tonic-clonic seizures (aHR 3.4, 95% CI 1.9-6.3, p<0.001). Mortality was higher in those with ASyS presenting as focal to bilateral tonic-clonic seizures on day 0 (aHR 2.8, 95% CI 1.4-5.6, p=0.004) and status epilepticus (aHR 14.2, 95% CI 3.5-58.8, p<0.001). The novel SeLECT-ASyS model, available as an app, outperformed a previous model in the derivation cohort (concordance statistic 0.68 vs. 0.58, p=0.02) and in the validation cohort (0.70 vs. 0.50, p=0.18). ConclusionsASyS timing and type significantly affect epilepsy and mortality risk after stroke, improving epilepsy prediction and guiding patient counseling.