gms | German Medical Science

Objective: Preoperative seizures are a common symptom in meningioma patients. Known risk factors include radiological features, localization but also WHO grading. Recently, brain invasion was added as an independent criterion for WHO II meningioma and its clinical importance was questioned in subsequent studies. Aim of our study was to evaluate whether brain invasion is an additional prognostic factor for seizures, independent from other histological grading parameters. The authors aim to investigate risk factors for preoperative seizure occurrence in patients withmeningioma WHO grade I and II.

Methods: We retrospectively assessed meningioma patients receiving surgical resection between 2008 and 2017 at our institution for the association betweenpreoperativeseizures and sex, age, tumor location, WHO grade with special focus on histopathological features like mitotic count or brain invasion. WHO grade III meningiomas were excluded for a clearer stratification of the study population. All samples were reclassified according to the 2017 WHO criteria. Reference point of the study was the date of surgery. Date of last follow up was 05/2019. Multivariate regression was used to identify variables significantly associated with preoperative seizures.

Results: Overall, 997 patients were eligible for multivariate logistic regression analyses of preoperative seizures. Reclassified for the new WHO grading, 918 patients harbored a Meningioma WHO I, 79 meningioma WHO grade II. 37 patients showed histological signs of brain invasion. Preoperative epilepsy was found in 93 (9.33%) patients, seven patients with histologically proven brain invasion presented with epilepsy, 30 patients did not show any signs of preoperative seizures. In univariate analysis, preoperative epilepsy was independent from patient age and sex. In multivariate regression analysis, the risk of seizures was significantly higher in patients with brain invasion (p=0.04, HR=2.369, CI=1.01-5.553). In contrast, elevated mitotic count was not associated with higher risk of preoperative epilepsy.

Conclusion: In a large cohort of meningioma patients, brain invasion was identified as an independent risk factor for preoperative seizures, regardless of any other signs of atypia. Therefore, in patients presenting with preoperative seizures special focus should be put on the brain/meningioma interface from a surgical as well as from a histopathological point of view.