Risk Factors for In-Hospital Seizures and New-Onset Epilepsy in Coil Embolization of Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE: This study aimed to determine risk factors for inpatient seizures and long-term epilepsy in patients receiving coil embolization for aneurysm-associated subarachnoid hemorrhage. METHODS: A retrospective chart review was conducted for patients admitted to the University of Pittsburgh Medical Center from 2010 to 2014 for subarachnoid hemorrhage. Only patients with coil embolization were included. Variables such as subdural hematoma, cerebral infarction, postoperative vasospasm, cerebral edema, and mass effect were collected. After discharge, patients were followed up to determine whether epilepsy had developed. The chi(2) test was used to assess univariate associations. Multivariable associations were assessed with a binary logistic regression model. RESULTS: The study included 175 patients, of whom 16 (9.1%) of the patients had seizures while they were inpatients. Five out of 73 patients met the criteria for epilepsy at follow-up. None of the patients with epilepsy after discharge had electrographic seizures while hospitalized. Vasospasm (odds ratio [OR] 6.88, 95% confidence interval [CI] 1.81-26.25), and Hunt and Hess grade 5 (OR 26.16, 95% CI 3.95-173.49) were significantly associated with in-hospital seizures in a multivariable analysis. Epileptiform discharges on electroencephalogram (EEG) were significantly associated with mass effect findings on brain imaging (OR 3.5, CI 1.05-11.69). CONCLUSION: Hunt and Hess grade 5 and vasospasm are independent risk factors for in-hospital seizures. In addition, mass effect is an independent risk factor for epileptiform discharges on EEG. Patients with these risk factors may benefit from continuous EEG. Our results may indicate that there is no association between electrographic seizures and development of epilepsy.