New onset epilepsy is a known sequella of AIS. Prior studies have been limited by small sample size and characterization of timing and frequency is lacking.

The frequency and timing of seizure after acute ischemic stroke (AIS) is poorly defined. Improved understanding is necessary to guide the use of anti-epileptic medications after AIS.

Using administrative data on all Emergency Department and inpatient visits in Florida (2005-2015), we identified patients with first time stroke. AIS and seizure were defined using validated ICD9 codes. The primary endpoint was first time seizure within the study period was 4 years post stroke. Patients were excluded for prior trauma, seizure, tumors, hemorrhage. We used a case-crossover design in which each patient served as her own control, by matching the study period with a control period of time 4 year prior to the stroke, using multivariate conditional logistic regression. Results are presented as OR [95% CI] or mean ± SD.

Among 294,351 patients with first time AIS, mean age 71.7 (±14), 52% were female, 70% were white, 17% were African American, and 11% were Hispanic. First time seizure was observed in 4,637 patients (1.6%), on average 610 (± 581) days post stroke. In case-crossover analysis, the likelihood of first time seizure was significantly increased following stroke (OR=2.04 [1.86 - 2.23]).

First time seizure after AIS is relatively uncommon late consequence of stroke. However, in case-crossover analysis, first time AIS resulted in a nearly two-fold increase in likelihood of first time seizure.