To identify predictors of post-discharge seizures in survivors of aneurysmal subarachnoid hemorrhage (aSAH) using electroencephalogram (EEG) data.

The predictors of post-discharge seizures using EEG features in patients with aSAH remain understudied. We sought to identify key predictors of seizures in aSAH survivors after hospital discharge.

We conducted a retrospective study of a consecutive cohort of aSAH patients admitted to an academic center from 2016 to 2024. A binary regression analysis was performed to evaluate the association between clinical, radiographic and EEG variables and post-discharge seizure occurrence.

We reviewed 458 cases with aSAH and included 352 survivors, mean age 57 years (SD 13.6), 61% female, 71% white. Nineteen patients (5%) experienced seizures after hospital discharge. The most common predictors of seizures after hospital discharge include the presence of highly epileptic features (electrographic seizures, lateralized periodic discharges) on EEG during hospitalization (OR 3.9, 95% CI 1.29-12; p=0.016), hospital length of stay (OR 1.03 per each day increase, 95% CI 1.002-1.06; p=0.033), and need for prescription of an anti-seizure medication at hospital discharge (OR 3.6, 95% CI 1.39-9.2; p=0.008). However, there was no association between age, Hunt and Hess grade, modified Fisher score, aneurysm location, securement procedure, presence of cerebral infarct during hospitalization or other EEG features and seizures after hospital discharge. 

The presence of highly epileptic features on EEG, hospital length of stay as a surrogate for complications, and the need for anti-seizure medications prescription appear to be important predictors of seizure in aSAH patients after hospital discharge. Larger prospective studies are needed to better risk stratify and justify the prescription of anti-seizure medications in a subset of aSAH survivors.