The value of routine electroencephalographic recordings in predicting postoperative seizures associated with meningioma surgery.

We analyzed the incidence of postoperative seizures in patients undergoing craniotomy for meningioma removal in order to determine whether EEG recordings are able to predict the incidence of postoperative seizures. We included 102 patients who had undergone surgery on intracranial meningiomas. Pre- and postoperative EEG images were divided into groups showing epileptiform activity including spikes or sharp waves, focal slowing, and normal activity. Follow-up was carried out using a standardized telephone questionnaire by an independent investigator after a mean of 889 days. Seizure outcome was determined by patient reports to the interviewer. Preoperatively obtained, abnormal EEGs correlated significantly to preoperative seizures (P<0.0005), but neither preoperative nor postoperative EEGs correlated to the incidence of postoperative seizures. It would seem that, while evaluation of some clinical parameters revealed a statistically significant correlation, pre- and early postoperative EEGs after meningioma surgery are not useful in determining the risk of postoperative seizures.