Postoperative epilepsy in patients undergoing craniotomy for glioblastoma multiforme

Glioblastoma multiforme (GBM) has associated with it one of the poorest pro gnoses among brain tumors. Postoperative seizures and the side effects of a nticonvulsants, routinely given for prophylactic purposes, add to patient m orbidity. The primary goal of this study was to determine who, of those und ergoing craniotomy for GEM resection, is at risk for epilepsy. We studied 7 2 consecutive patients who underwent craniotomy and palliative resection fo r GEM. Twenty-nine presented with seizures and 17 had postoperative seizure s. All patients were treated with a postoperative anticonvulsant for at lea st six months; anticonvulsants were continued longer if there was a postope rative seizure. Patient factors examined for an association with risk for p ostoperative seizure included age: sex, tumor size, tumor location, adjuvan t therapy, postoperative complications and history of preoperative seizures . The majority of patients with no prior seizure history and who seized pos toperatively had their first seizure after withdrawal from their anticonvul sant medication. Ail, but one, of the patients with both pre- and postopera tive seizures had their first postoperative seizure while still on anticonv ulsants. Smaller tumor size and frontal resection were associated with an i ncreased risk of postoperative seizures. Our data suggests that those who d o not present with seizures and undergo GEM resection may still be prone to seize but more easily protected from postoperative seizures with anticonvu lsant therapy than patients who present with seizures; resection of frontal tumors and smaller tumors seemed to indicate an increased risk for postope rative seizures.