Risk of Poststroke Epilepsy Among Young Adults With Ischemic Stroke or Intracerebral Hemorrhage

Importance: Poststroke epilepsy (PSE) is a major complication among young adults and is associated with problems with functional recovery and daily life. Although scores have been developed to predict risk of PSE, they have not been validated among patients with stroke at a young age. Objectives: To investigate both the risk of and risk factors for PSE at a young age and validate current PSE risk scores among a cohort of young adults. Design, Setting, and Participants: This cohort study used data from ODYSSEY (Observational Dutch Young Symptomatic Stroke Study), a prospective cohort study conducted among 17 hospitals in the Netherlands between May 27, 2013, and March 3, 2021, with follow-up until February 28, 2024. Participants included 1388 consecutive patients aged 18 to 49 years with neuroimaging-proven ischemic stroke or intracerebral hemorrhage (ICH) and without a history of epilepsy. Statistical analysis took place between June and August 2024. Exposure: First-ever neuroimaging-proven ischemic stroke or ICH. Main Outcomes and Measures: Poststroke epilepsy was defined as at least 1 remote symptomatic seizure (>7 days). Cumulative incidence functions were used to calculate the 5-year risk of PSE. Fine-Gray regression models were used to identify risk factors associated with PSE (age, sex, clinical stroke, and neuroimaging variables). The performances of the SeLECT (severity of stroke, large-artery atherosclerosis, early seizure, cortical involvement, and territory of middle cerebral artery) 2.0 risk score (for ischemic stroke) and the CAVE (cortical involvement, age, bleeding volume, and early seizure) risk score (for ICH) were assessed with C statistics and calibration bar plots. Results: This study included 1388 patients (ischemic stroke, 1231 [88.7%]; ICH, 157 [11.3%]; median age, 44.1 years [IQR, 38.0-47.4 years]; 736 men [53.0%]; median follow-up, 5.3 years [IQR, 3.4-7.4 years]), of whom 57 (4.1%) developed PSE. The 5-year cumulative risk of PSE was 3.7% (95% CI, 0.2%-4.8%) after ischemic stroke and 7.6% (95% CI, 3.5%-11.8%) after ICH. Factors associated with PSE after ischemic stroke were an acute symptomatic seizure (<7 days) (hazard ratio [HR], 10.83 [95% CI, 2.05-57.07]; P = .005) and cortical involvement (HR, 5.35 [95% CI, 1.85-15.49]; P = .002). The only factor associated with PSE after ICH was cortical involvement (HR, 8.20 [95% CI, 2.22-30.25]; P = .002). The C statistic was 0.78 (95% CI, 0.71-0.84) for the SeLECT 2.0 risk score and 0.83 (95% CI, 0.76-0.90) for the CAVE risk score, and calibration was good for both scores. Conclusion: This study suggests that the risk of PSE among young adults is relatively low and that the factors that were associated with PSE were similar to variables included in the existing risk scores, which can therefore also be applied for young adults after stroke. Future clinical trials should investigate the optimal primary and secondary prophylaxis for patients at high risk.