Independent Risk Factors for Postoperative Seizures in Chronic Subdural Hematoma Identified by Multiple Logistic Regression Analysis

Abstract

Postoperative seizures are potential complications of chronic subdural hematoma (cSDH). Knowledge of risk factors may help to identify patients that may benefit from antiepileptic prophylaxis. A total of 101 patients (mean age, 70.1 ± 32.1 years) with surgical evacuation of cSDH were enrolled. We retrospectively collected patient characteristics, hematoma specifics, and procedural aspects and evaluated their impact on postoperative seizures within a 14-day follow-up period by means of bivariate logistic regression analysis. Postoperative seizures occurred in 14 patients (13.9%). At discharge, the mean Markwalder grading scale score was 1.1 ± 1.1 and 0.5 ± 0.8 in patients with and without seizures, respectively (P= 0.04). In the univariate analysis, preoperative midline shift (8.3 vs. 4.5 mm, P= 0.045), open craniotomy (85.7% vs. 55.2%, P= 0.031), and membranectomy (57.1% vs. 20.7%, P= 0.004) were significantly associated with postoperative seizures, respectively. In the multivariate analysis, preoperative midline shift (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.01-1.26; P= 0.029) and membranectomy (OR, 3.9; 95% CI, 1.0-15.0; P= 0.048) remained as independent risk factors for seizures. Perioperative antiepileptic prophylaxis may be recommended in patients with preoperative midline shift. Membranectomy may not be routinely applied during surgery.