Subarachnoid Extension of Hemorrhage is Associated with Early Seizures in Primary Intracerebral Hemorrhage

Background: Seizures are common in patients with subarachnoid hemorrhage, potentially by inciting cortical irritability. Seizures are also commonly seen after intracerebral hemorrhage (ICH), although the mechanisms and risk factors within that population are not well understood. The objective of this study is to evaluate whether subarachnoid hemorrhage extension (SAHE) is associated with early seizures in patients with primary ICH. Methods: Patients with primary ICH were enrolled into a prospective registry between December 2006 and July 2012. Patients were managed per a structured protocol. SAHE was identified on imaging by expert reviewers blinded to outcomes. Electroencephalograms were routinely obtained in patients with unexplained, poor level of arousal. Seizure was determined by clinically observed convulsions or traditional electroencephalographic criteria. Early seizures were defined as occurring within 3 days of hemorrhage. A binary logistic regression model was developed to test whether the occurrence of SAHE was independently associated with seizures. Results: A total of 234 patients were studied. Of these, 93 (40%) had SAHE and 9 (4%) had early seizures. SAHE was associated with early seizures (P = .03). No additional variables were identified by regression modeling to mediate the association between SAHE and early seizures (odds ratio 5.62 [95% confidence interval 1.14-27.7], P = .034). Conclusions: SAHE is associated with early seizures in patients with primary ICH. Further study is needed to confirm these findings and determine whether modifications to routine care based on the presence of SAHE would be of benefit.