Epilepsy Incidence in Patients with Post-Stroke Aphasia: A Nationwide, Population-Based Cohort Study

Post-stroke epilepsy (PSE) affects 2-20% of stroke survivors. Whether post-stroke aphasia (PSA) is associated with a further increase in this risk remains unclear. This study aimed to compare PSE risk between stroke patients with and without aphasia.

Using Taiwan National Health Insurance claims data, patients aged ≥18 years hospitalized for a first stroke between 2003 and 2007 were identified. Those with and without PSA, free from epilepsy during admission or within 90 days after discharge, were followed until December 31, 2020. Propensity score-matched cohorts were also established. Cox proportional hazards models were used to estimate hazard ratios (HR) for PSE. Adjusted rate differences (aRDs) were calculated to quantify excess risk.

With a median follow-up of 7.56 years for the PSA group (N=23,431) and 8.67 years for the non-aphasia group (N=130,058), the incidence of PSE was higher in patients with aphasia than in those without aphasia (13.02 vs. 4.56 per 1,000 person-years; aRD 2.96, 95% confidence interval [CI] 2.60-3.37). Excess risk was higher in males than in females (aRD 3.11 vs. 2.38 per 1,000 person-years), higher in younger than in older adults (aRD 3.52, 2.42, and 2.88 per 1,000 person-years in <45, 45-64, and ≥65-year groups, respectively), and higher in hemorrhagic than in ischemic stroke (3.52 vs. 2.64 per 1,000 person-years). The association was strongest during the first year after stroke and declined thereafter.

Patients with post-stroke aphasia are at increased risk of epilepsy, regardless of age, sex, and stroke type.