Seizures in Acute Stroke: Predictors and Prognostic Significance

Abstract

Background Despite the common occurrence of seizures during the early phase of stroke (ES), the effect of ES on prognosis is not known. We determined the relationships between ES and stroke outcome and identified predictors of ES. Methods In this community-based study, we prospectively and consecutively studied 1197 patients with acute stroke. We determined the number and type of seizures, initial stroke severity, infarct size, mortality, and outcome in survivors. Stroke severity was measured on admission, weekly, and at discharge using the Scandinavian Stroke Scale (SSS). Multiple logistic and linear regression outcome analyses included relevant confounders and potential predictors, including age, gender, stroke severity on admission, atrial fibrillation, ischemic heart disease, diabetes, blood glucose level on admission, claudication, and hypertension. Results Fifty patients (4.2%) had seizures within 14 days of the stroke. In the multivariate analyses, only initial stroke severity was related to ES; stroke type and lesion localization were not related. For each 10-point increase in stroke severity (SSS score), the relative risk of ES increased by a factor of 1.65 (95% confidence interval, 1.4 to 1.9) ( P <.0001). ES did not influence the risk of death during hospital stay ( P =.56). In survivors, ES was related to a better outcome, equivalent to an increased SSS score of 5.7 points (SE [b]=1.8; P =.002). Conclusions The decisive factor of ES was initial stroke severity. ES per se was not related to mortality. Surprisingly, in survivors, ES predicted a better outcome. We explain this finding by a relatively larger ischemic penumbra in patients who have an ES after a stroke.