Seizures after stroke - A prospective multicenter study

Background: Studies of seizures after stroke have largely been retrospectiv e, with small patient numbers and limited statistical analysis. Much of the doctrine about seizures after stroke is not evidenced based. Objective: To determine the incidence, outcome, and risk factors for seizur es after stroke. Design: International, multicenter, prospective, analytic inception cohort study conducted for 34 months. Patients and Setting: There were 2021 consecutive patients with acute strok e admitted to university teaching hospitals with established stroke units. After exclusion of 124 patients with previous epilepsy or without computed tomographic diagnosis, 1897 were available for analysis. Mean follow-up was 9 months. Main Outcome Measures: Occurrence of 1 or more seizures after stroke, strok e disability, and death after stroke. Results: Seizures occurred in 168 (8.9%) of 1897 patients with stroke (28 [ 10.6%] of 265 with hemorrhagic and 140 [8.6%] of 1632 with ischemic stroke) . On Kaplan-Meier survival analysis, patients with hemorrhagic stroke were at significantly greater risk of seizures (P=.002), with an almost 2-fold i ncrease in risk of seizure after stroke (hazard ratio [HR], 1.85; 95% confi dence interval [CI], 1.26-2.73, P=.002). On multivariate analysis, risk fac tors for seizures after ischemic stroke were cortical location of infarctio n (HR, 2.09; 95% CI, 1.19-3.68; P<.01) and stroke disability (HR, 2.10; 95% CI, 1.16-3.82; P<.02). The only risk factor for seizures after hemorrhagic stroke was cortical location (HR, 3.16; 95% CI, 1.35-7.40; P<.008). Recurr ent seizures (epilepsy) occurred in 47 (2.5%) of 1897 patients. Late onset of the first seizure was an independent risk factor for epilepsy after isch emic stroke (HR, 12.37; 95% CI, 4.74-32.32; P<.001) but not after hemorrhag ic stroke. Conclusions: Seizures occur more commonly with hemorrhagic stroke than with ischemic stroke. Only a small minority later develop epilepsy. Patients wi th a disabling cortical infarct or a cortical hemorrhage are more likely to have seizures after stroke; those with late-onset seizures are at greater risk of epilepsy.