Strokes or Seizures? What’s the Score?

Abstract

Prediction of Late Seizures After Ischemic Stroke With a Novel Prognostic Model (the SeLECT Score): A Multivariable Prediction Model Development and Validation Study Galovic M, Döhler N, Erdélyi-Canavese B, et al. Lancet Neurol. 2018;17(2):143-152. doi:10.1016/S1474-4422(17)30404-0 PMID: 29413315 Background: Stroke is one of the leading causes of acquired epilepsy in adults. An instrument to predict whether people are at high risk of developing poststroke seizures is not available. We aimed to develop and validate a prognostic model of late (>7 days) seizures after ischemic stroke. Methods: In this multivariable prediction model development and validation study, we developed the SeLECT score based on 5 clinical predictors in 1200 participants who had an ischemic stroke in Switzerland using backward elimination of a multivariable Cox proportional hazards model. We externally validated this score in 1169 participants from 3 independent international cohorts in Austria, Germany, and Italy and assessed its performance with the concordance statistic and calibration plots. Findings: Data were complete for 99.2% of the predictors (99.2% for Switzerland, 100% for Austria, 97% for Germany, and 99.7% for Italy) and 100% of the outcome parameters. Overall, the risk of late seizures was 4% (95% confidence interval [CI]: 4-5) 1 year after stroke and 8% (6-9) 5 years after stroke. The final model included 5 variables and was named SeLECT on the basis of the first letters of the included parameters (severity of stroke, large-artery atherosclerotic etiology, early seizures, cortical involvement, and territory of middle cerebral artery [MCA] involvement). The lowest SeLECT value (0 points) was associated with a 0.7% (95% CI: 0.4-1.0) risk of late seizures within 1 year after stroke (1.3% [95% CI: 0.7-1.8] within 5 years), whereas the highest value (9 points) predicted a 63% (42-77) risk of late seizures within 1 year (83% [62-93] within 5 years). The model had an overall concordance statistic of 0.77 (95% CI: 0.71-0.82) in the validation cohorts. Calibration plots indicated high agreement of predicted and observed outcomes. Interpretation: This easily applied instrument was shown to be a good predictor of the risk of late seizures after stroke in 3 external validation cohorts and is freely available as a smartphone app. The SeLECT score has the potential to identify individuals at high risk of seizures and is a step toward more personalized medicine. It can inform the selection of an enriched population for antiepileptogenic treatment trials and will guide the recruitment for biomarker studies of epileptogenesis. : Population-Based Assessment of the Long-Term Risk of Seizures in Survivors of Stroke Merkler AE, Gialdini G, Lerario MP, et al. Stroke. 2018;49(6):1319-1324. doi:10.1161/STROKEAHA.117.020178. Epub April 25, 2018. PMID: 29695463 Background and Purpose: We sought to determine the long-term risk of seizures after stroke according to age, sex, race, and stroke subtype. Methods: We performed a retrospective cohort study using administrative claims from 2 complementary patient data sets. First, we analyzed data from all emergency department visits and hospitalizations in California, Florida, and New York from 2005 to 2013. Second, we evaluated inpatient and outpatient claims from a nationally representative 5% random sample of Medicare beneficiaries. Our cohort consisted of all adults at the time of acute stroke hospitalization without a prior history of seizures. Our outcome was seizure occurring after hospital discharge for stroke. Poisson regression and demographic data were used to calculate age-, sex-, and race-standardized incidence rate ratios (IRR). Results: Among 777 276 patients in the multistate cohort, the annual incidence of seizures was 1.68% (95% confidence interval [CI]: 1.67%-1.70%) after stroke versus 0.15% (95% CI: 0.15%-0.15%) among the general population (IRR: 7.3; 95% CI: 7.3-7.4). By 8 years, the cumulative rate of any emergency department visit or hospitalization for seizure was 9.27% (95% CI: 9.16%-9.38%) after stroke versus 1.21% (95% CI: 1.21%-1.22%) in the general population. Stroke was more strongly associated with a subsequent seizure among patients <65 years of age (IRR: 12.0; 95% CI: 11.9-12.2) than in patients ≥65 years of age (IRR: 5.5; 95% CI: 5.4-5.5), and in the multistate analysis, the association between stroke and seizure was stronger among nonwhite patients (IRR: 11.0; 95% CI: 10.8-11.2) than among white patients (IRR: 7.3; 95% CI: 7.2-7.4). Risks were especially elevated after intracerebral hemorrhage (IRR: 13.3; 95% CI: 13.0-13.6) and subarachnoid hemorrhage (IRR: 13.2; 95% CI: 12.8-13.7). Our study of Medicare beneficiaries confirmed these findings. Conclusions: Almost 10% of patients with stroke will develop seizures within a decade. Hemorrhagic stroke, nonwhite race, and younger age seem to confer the greatest risk of developing seizures.