Meningiomas of the rolandic region: risk factors for motor deficit and role of intra-operative monitoring.

Objective Meningiomas of the rolandic region are associated to high risk of postoperative motor defcits. This study discusses the factors afecting motor outcome and recurrences from the analysis of a monoinstitutional case series and eight studies from a literature review. Methods Data of 75 patients who underwent surgery for meningioma of the rolandic region were retrospectively reviewed. The analyzed factors included tumor location and size, clinical presentation, magnetic resonance imaging (MRI) and surgical fndings, brain-tumor interface, extent of resection, postoperative outcome and recurrence. Eight studies from literature on rolandic meningiomas treated with or without intraoperative monitoring (IOM) were reviewed with the aim to defne the impact of IOM on the extent of resection and motor outcome. Results Among the 75 patients of the personal series, the meningioma was on the brain convexity in 34 (46%), at the parasagittal region in 28 (37%) and at the falx in 13 (17%). The brain-tumor interface was preserved in 53 cases (71%) at MRI and in 56 (75%) at surgical exploration. Simpson grade I resection was obtained in 43% of patients, grade II in 33%, grade III in 15% and grade IV in 9%. The motor function worsened postoperatively in 9 among 32 cases with preoperative defcit (28%) and in 5 among 43 with no preoperative defcit (11.5%); defnitive motor defcit was evidenced in overall series at follow-up in 7 (9.3%). Patients with meningioma with lost arachnoid interface had signifcant higher rates of worsened postoperative motor defcit (p=0.01) and seizures (p=0.033). Recurrence occurred in 8 patients (11%). The analysis of the 8 reviewed studies (4 with and 4 without IOM) shows in the group without IOM higher rates of Simpson grades I and II resection (p=0.02) and lower rates of grades IV resection (p=0.002); no signifcant diferences in postoperative immediate and long-term motor defcits were evidenced between the two groups. Conclusions Data from literature review show that the use of IOM does not afect the postoperative motor defcit Therefore, its role in rolandic meningiomas resection remains to be determined and will be defned in further studies.