Risk of seizures before and after neurosurgical treatment of intracranial meningiomas

Objective: To identify variables associated with the development of pre- and postoperative seizures in patients who underwent surgical resection of intracranial meningiomas, in a patient cohort not routinely treated prophylactically with antiepileptic drugs (AED). Patients mid methods: Retrospective cohort study of 295 patients that underwent resection of a supratentorial meningioma at Odense University Hospital in between 2007-2015. Multivariate logistic regression was used to identify variables significantly correlating with pre- and postoperative seizures. Retrospective chart review was used to identify the rates of seizure incidence in patients, and the effect of AED on them. Results: The presence of peritumoral edema (OR:18.00, 7.44-43.58) was identified as predictor of preoperative seizure, while headache (OR:0.43, 0.22-0.84) and neurological deficit (OR:0.18, 0.09-0.39) were associated with a reduced incidence of preoperative seizures. The rates of postoperative seizure were increased in meningiomas in the left side (OR:1.91, 1.11-3.29), and reduced for tumor location in the convexity/parasagittal/falx (OR:0.72, 0.59-0.88) as well as in the absence of postoperative complications (OR:0.19, 0.10-0.36). 24.4% of the patients experienced seizures preoperatively, and a complete seizure freedom was achieved in 63.9% of them. 75.6% of the patients did not experience seizures preoperatively, but 15.2% of them then developed seizures postoperatively. A total of 20.3% of the patients experienced seizures after surgery. Time to first seizure in patients that did not experience seizures preoperatively but developed seizures after surgery, was one week (47%). However, first time postoperative seizures were also observed within one month postoperative (21%) and three months after surgery (32%). AED had a treatment success rate of 98.2% in preoperative seizures, and 98.0% in postoperative seizures. Conclusion: Seizures after supratentorial meningioma surgery is common also in patients with no seizures preoperatively and mainly occurs within the first three postoperative months. AED are effective in controlling seizures.