A NATIONWIDE, POPULATION-BASED COHORT STUDY OF EPILEPSY INCIDENCE IN PATIENTS WITH POST-STROKE APHASIA

Abstract

Abstract Introduction: Post-stroke epilepsy (PSE) affects 2–20% of stroke survivors. Post-stroke aphasia is associated with a further increase in this risk. Identifying factors associated with developing PSE potentially could guide targeted interventions in future trials. Methods: We utilized Taiwan’s National Health Insurance claims data to identify individuals aged 18 years or older who were hospitalized for a first stroke between 2003 and 2007, including those diagnosed with aphasia during admission or within 90 days after discharge. Beginning 91 days following hospital discharge, the incidence of epilepsy was compared between stroke patients with and without aphasia until December 31, 2020. Hazard ratios controlling for other risk factors for epilepsy were derived using Cox proportional hazards regression, and we calculated adjusted rate differences to quantify the absolute magnitude of the excess risk. Results: With a median follow-up of 7.56 years for the aphasia group (n = 23,431) and 8.67 years for the non-aphasia group (n = 130,058), the incidence of post-stroke epilepsy was higher among patients with aphasia than in those without aphasia (13.02 vs. 4.56 per 1000 person-years, adjusted rate difference [aRD] 2.96, 95% CI 2.60–3.37 per 1,000 person-years). Excess risk was similar (aRD 2.38 and 3.11 per 1,000 person-years) in female and male participants, respectively, and somewhat higher in younger than in older adults (aRD 3.52, 2.42, and 2.88 per 1,000 person-years in the <45, 45–64, and ≥65 age groups, respectively). The excess rate of epilepsy associated with the development of aphasia was 3.52 and 2.64 per 1,000 person-years among those with hemorrhagic and ischemic stroke, respectively. The association was strongest in the first year of follow-up after stroke and declined thereafter. Conclusion: Patients with post-stroke aphasia are at increased risk of epilepsy irrespective of age, sex, and stroke type.