Incidence of seizures after surgery for supratentorial meningiomas: a modern analysis

The authors have assessed the incidence of postoperative seizures in 158 patients with supratentorial meningiomas diagnosed by computerized tomography (CT) and/or magnetic resonance (MR) imaging, which theoretically should lead to early diagnosis and treatment and the potential for improved seizure outcome. Univariate chi-square and logistic regression analyses were performed 24 independent variables against the outcome variable of occurrence of a postoperative seizure. The median duration of preoperative seizures was 1 month, considerably shorter than that found in studies conducted prior to the advent of CT and MR imaging. Of 63 patients with a history of preoperative seizures, 40 (63.5%) had complete cessation of seizures after surgery. Twelve (92.3%) of 13 patients with one to three postoperative seizures eventually achieved complete seizure control, whereas only four (40%) of 10 patients with more than three postoperative seizures achieved this result. Overall 88.9% of patients with preoperative seizures achieved complete seizure control postoperatively. Multivariate analysis was used to identify six variables that were predictive of the occurrence of postoperative seizures: preoperative seizure history preoperative language disturbance, extent of tumor removal, parietal location of tumor, postoperative anticonvulsant medication status, and postoperative hydrocephalus. These variables were incorporated into a diagnostic model designed to predict the risk of a postoperative seizure following meningioma surgery. On the basis of their findings, the authors conclude that earlier detection and treatment of supratentorial meningiomas improve seizure outcome in patients with preoperative epilepsy. Furthermore an assessment of the risk of postoperative seizures may help guide decisions concerning weaning patients from anticonvulsant medications postoperatively.