Associations of Stroke With Risk of Epilepsy: Results From the Atherosclerosis Risk in Communities (ARIC) Study

Objective To estimate the risk of epilepsy associated with stroke in a community-based cohort, with consideration of stroke type, number, and severity. Methods Data from 15,100 Atherosclerosis Risk in Communities (ARIC) Study participants without stroke at baseline (1987-1989) were analyzed through 12/31/2022. Adjudicated stroke events were modeled as time-varying exposures. Epilepsy was defined using International Classification of Diseases Ninth/Tenth Revisions codes. Adjusted Fine and Gray proportional hazards models were used to estimate the risk of epilepsy associated with stroke. Results At baseline, the mean age of participants was 54 years, 55% were female, and 26% were of Black race. Over a median of 27 years, 1553 incident all-cause strokes occurred. The risk of epilepsy was higher among individuals with versus without incident stroke (HR = 1.75, 95% CI = 1.50-2.04). There was evidence for interaction by age (p-interaction = 0.03) whereby the risk of epilepsy associated with stroke was higher among individuals with younger versus older baseline age. Compared to no stroke, the point estimate for the risk of epilepsy associated with subarachnoid hemorrhage (HR = 2.94, 95% CI = 1.67-5.17) was higher than that for the risk of epilepsy associated with ischemic stroke (HR = 1.65, 95% CI = 1.40-1.94) and hemorrhagic stroke (HR = 1.47, 95% CI = 0.95, 2.27). The risk of epilepsy was similar by the number of incident strokes but was greater with increasing ischemic stroke severity. Interpretation The risk of epilepsy was increased after an incident stroke. This work identifies high-risk subgroups, including younger individuals, individuals with subarachnoid hemorrhage, and individuals with more severe ischemic strokes, who may benefit from closer clinical monitoring for seizures/epilepsy after a stroke.