Stroke Survivors Have Higher Risk for Subsequent Seizures Than General Population

A retrospective study published in Stroke suggests that patients with stroke have an approximately 7-fold higher risk of developing seizures after an index stroke event compared with the general population. Factors associated with this higher poststroke seizure risk include hemorrhagic stroke, younger age, and nonwhite race.

Investigators analyzed administrative claims from 2 patient data sets, including 1 data set containing emergency department visits and hospitalizations and another data set containing inpatient and outpatient claims from a 5% random sample of Medicare beneficiaries (N=777,276). Participants included in the study were free of seizures at the time of acute stroke hospitalization. The primary outcome was seizure occurrence after discharge from the hospital for stroke.

After hospital discharge, a total of 45,708 seizures occurred among the population of patients with stroke, representing an annual seizure incidence rate of 1.68% (95% CI, 1.67%-1.70%) after stroke vs 0.15% (95% CI, 0.15%-0.15%) for the general population (incidence rate ratio [IRR], 7.3; 95% CI, 7.3-7.4). At 8 years, the cumulative rate of any hospitalization or emergency department visit for seizure was higher among patients with stroke vs the general population (9.27% [95% CI, 9.16%-9.38%] vs 1.21% [95% CI, 1.21%-1.22%], respectively).

Patients with stroke who were aged <65 years were more likely to experience seizures compared with patients aged ≥65 years (IRR, 12.0 [95% CI, 11.9-12.2] vs IRR, 5.5 [95% CI, 5.4-5.5], respectively). In addition, there was a stronger association between stroke and seizure occurrence in nonwhite patients vs white patients (IRR, 11.0 [95% CI, 10.8-11.2] vs IRR, 7.3 [95% CI, 7.2-7.4], respectively) and among those with an intracerebral hemorrhage (IRR, 13.3; 95% CI, 13.0-13.6) and subarachnoid hemorrhage (IRR, 13.2; 95% CI, 12.8-13.7).

A limitation of the study includes the analysis of only seizure events that necessitated emergency department or hospital admission, which potentially resulted in seizure risk underestimation.

Additional research regarding “the epidemiology and pathophysiology of poststroke seizures may lead to improved methods of risk stratification and prevention.”

Reference

Merkler AE, Gialdini G, Lerario MP, et al. Population-based assessment of the long-term risk of seizures in survivors of stroke [published online April 25, 2018]. Stroke. doi: 10.1161/STROKEAHA.117.020178