Introduction: While numerous retrospective studies have documented a survival benefit associated with extent of resection in glioblastoma, postoperative morbidities such as seizures and risk factors associated with them have been less frequently described, often in small cohorts. We sought to define risk factors for postoperative seizures in a large patient cohort.
Methods: Retrospective chart review of 1094 glioblastoma patients who underwent craniotomy at our institution 2004-2013
Results: The mean age was 56 (range=6-91) with 39% female. Mean tumor diameter was 3.7 cm. GTR was achieved in 38% of patients. Postoperative seizure occurred after 6.7% of surgeries. Multivariate analysis of demographic, preoperative (tumor size, number of surgery, hyponatremia), and postoperative (hyponatremia, mutation analyses, EOR, LOS, focal motor deficits, use of postoperative AEDs) variables was conducted. Hyponatremia (P=0.02; HR=1.3), and KPS (P=0.04; HR=4.2 per 10 point) were the only risk factors for postoperative seizure. Other variables including age (P=0.07), gender (p=0.4), prophylactic AED use (P=0.6-0.8), number of surgery (P=0.9), and tumor mutations (EGFR/p53/IDH; p=0.6-0.8) did not influence postoperative seizure risk.
Conclusions: We identified preoperative hyponatremia and KPS as risk factors for postoperative seizures, while prophylactic AED use did not reduce this risk. Although retrospective, deriving this information from a large cohort of over 1000 patients increases its value in preoperative risk discussion with patients.
Patient Care: Our findings help neurosurgeons better understand risk factors associated with postoperative seizure in GBM patients which can help in the discussion with patients preoperatively, while eliminating the usage of prophylactic AED, which is both costly, and of no benefit.
Learning Objectives: 1. To better understand the risk factors associated with postoperative seizure in GBM patients
2. To understand that prophylactic AED usage does not reduce the risk of seizure in post-op GBM patients