Abstracts

Rationale: Stroke is the most common cause of seizures and epilepsy in the elderly population. Early seizures (ES) were reported to be predictors of the late seizures and worse stroke outcome. There are many studies looking at the risk factors of ES after stroke, however, the side of the lesion was neglected. The aim of our study was to evaluate the incidence of ES after ischemic (IS) and hemorrhagic stroke (HS) and to assess the difference between the left- and right-hemispheric stroke.Methods: A prospective single-center study included 1427 consecutive patients (age 66.3 ± 8.4; 863 ischemic, 564 hemorrhagic (SAH excluded); NIHSS at admission 13.1 ± 8.2 ) with first-ever carotid stroke, admitted to the intensive care unit of the Neurology department of the Russian National Research Medical University. Patients with transient ischemic attack or a history of epilepsy were not included in the study. There were 607 patients with left hemispheric stroke (322 ischemic, 285 hemorrhagic). Patients were followed until discharge (21-28 days after the stroke onset) or until death. Chi-square test for categorical variables and Student’s t-test or Wilcoxon rank-sum test for continuous variables, nonparametric Kruskal-Wallis ANOVA, univaruate and multivariate logistic regression analysis were evaluated.Results: ES occurred in 91 of 1427 patients (6.3%), including 40 (4.6%) of 863 with IS and 51 (9.0%) of 564 with HS. The incidence of ES in HS was significantly higher than in IS (p= 0.0009). OR HS vs. IS = 2.045; CI 1.3 – 3.1 (p< 0.001). The majority of ES (67.5% in IS and 63% in HS) occurred within the first 24 hours after stroke; most of them were focal or focal secondarily generalized. The proportion of patients with left hemispheric stroke was 42.5% (37.3% in IS and 50.5% in HS). However, in patients with ES the proportion of patients with left hemispheric stroke was higher - 75.8 % (72.5% in IS and 78.4% in HS). Patients with right and left hemispheric stroke were similar in NIHSS values at admission, major risk factors, lesion location (cortical/subcortical) and volume (assessed by CT). In the univariate analysis left hemispheric stroke was a significant risk factor for ES in all patients (OR = 4.65; CI 2.84 – 7.61, p=0.000), in patients with IS (OR = 4.76 (CI 2.34 – 9.69, p=0.000), and HS (OR = 3.97 (CI 1.99 – 7.93, p=0.000). In the multivariate analysis, including age, gender, major stroke risk factors, stroke type, left hemispheric stroke remained highly significant (p=0.000) risk factor for early seizures for both IS OR = 4.28 (CI 2.04 – 8.99) and HS (OR = 3.94 (CI 1.66 – 9.34).Conclusions: Early seizures develop in substantial proportion of stroke patients; the incidence of ES in HS is significantly higher than in IS. Left hemispheric stroke as an independent risk factor of ES has not been previously reported. Further translational studies are needed to evaluate its mechanisms. Higher incidence of ES might be considered as one of the reasons of previously reported worse outcome of the left-hemispheric infarcts.