Risk factors for a first epileptic seizure after stroke: A case control study

Abstract Introduction The risk of seizures increases after stroke, but not all risk factors are known. We aimed to identify factors that increase the risk of a first seizure after a stroke. Methods Multicenter case–control study of 161 patients with a first seizure after stroke (105 provoked/acute and 56 unprovoked/remote symptomatic) matched to 279 hospital stroke controls by center, gender, age and timing of stroke. Results The risk of first seizure (odds ratio (OR), 95% confidence limits (CL)) was 3.6 (2.4–5.5) for cortical involvement, 2.5 (1.2–5.3) for multiple CT-scan lesions, 2.4 (1.5–3.9) for supratentorial lesions, 2.4 (1.6–3.7) for prior lesions on CT-scan, 2.1 (1.1–4.7) for family history of seizures, 2.0 (1.1–3.6) for use of epileptogenic drugs, 1.7 (1.0–2.9) for large lesions, 1.6 (1.0–2.8) for hemorrhagic lesions, and 1.4 (1.0–2.2) for cortical atrophy. After multivariate analysis, including all the factors significant in univariate analysis, the strongest independent predictor of a first seizure was cortical involvement (OR 3.3; 95% CL = 2.1–5.0), followed by prior lesions (2.2; 1.4–3.4) and hemorrhagic stroke (1.8, 1.0–3.2). The multivariate analysis model for remote symptomatic seizures included cortical involvement, large size, and prior lesions; the model for acute seizures included cortical involvement, alcohol consumption > 50 g/day, hemorrhagic stroke, and prior lesions on CT-scan. Discussion Cortical involvement, the presence of prior lesions on CT-scan, and hemorrhagic lesion are the most important risk factors for a first-ever seizure after stroke.