New-onset seizure during and after brain tumor excision: a risk assessment analysis

OBJECTIVE Prophylactic use of antiepileptic drugs (AEDs) in seizure-naïve brain tumor patients remains a topic of debate. This study aimed to characterize a subset of patients at highest risk for new-onset perioperative seizures (i.e., intraoperative and postoperative seizures occurring within 30 days of surgery) who may benefit from prophylactic AEDs. METHODS The authors conducted a retrospective case-control study of all adults who had undergone tumor resection or biopsy at the authors' institution between January 1, 2004, and June 31, 2015. All patients with a history of preoperative seizures, posterior fossa tumors, pituitary tumors, and parasellar tumors were excluded. A control group was matched to the seizure patients according to age (± 0 years). Demographic data, clinical status, operative data, and postoperative course data were collected and analyzed. RESULTS Among 1693 patients who underwent tumor resection or biopsy, 549 (32.4%) had never had a preoperative seizure. Of these 549 patients, 25 (4.6%) suffered a perioperative seizure (Group 1). A total of 524 patients (95.4%) who remained seizure free were matched to Group 1 according to age (± 0 years), resulting in 132 control patients (Group 2), at an approximate ratio of 1:5. There were no differences between the patient groups in terms of age, sex, race, relationship status, and neurological deficits on presentation. Histological subtype (infiltrating glioma vs meningioma vs other, p = 0.041), intradural tumor location (p < 0.001), intraoperative cortical stimulation (p = 0.004), and extent of resection (less than gross total, p = 0.002) were associated with the occurrence of perioperative seizures. CONCLUSIONS While most seizure-naïve brain tumor patients do not benefit from perioperative seizure prophylaxis, such treatment should be considered in high-risk patients with supratentorial intradural tumors, in patients undergoing intraoperative cortical stimulation, and in patients in whom subtotal resection is likely.