Surgical treatment of meningiomas located in the rolandic area: the role of navigated transcranial magnetic stimulation for preoperative planning, surgical strategy, and prediction of arachnoidal cleavage and motor outcome

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>Surgical treatment of convexity meningiomas is usually considered a low-risk procedure. Nevertheless, the risk of postoperative motor deficits is higher (7.1%–24.7% of all cases) for lesions located in the rolandic region, especially when an arachnoidal cleavage plane with the motor pathway is not identifiable. The authors analyzed the possible role of navigated transcranial magnetic stimulation (nTMS) for planning resection of rolandic meningiomas and predicting the presence or lack of an intraoperative arachnoidal cleavage plane as well as the postoperative motor outcome.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Clinical data were retrospectively collected from surgical cases involving patients affected by convexity, parasagittal, or falx meningiomas involving the rolandic region, who received preoperative nTMS mapping of the motor cortex (M1) and nTMS-based diffusion tensor imaging (DTI) fiber tracking of the corticospinal tract before surgery at 2 different neurosurgical centers. Surgeons’ self-reported evaluation of the impact of nTMS-based mapping on surgical strategy was analyzed. Moreover, the nTMS mapping accuracy was evaluated in comparison with intraoperative neurophysiological mapping (IONM). Lastly, we assessed the role of nTMS as well as other pre- and intraoperative parameters for predicting the patients’ motor outcome and the presence or absence of an intraoperative arachnoidal cleavage plane.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>Forty-seven patients were included in this study. The nTMS-based planning was considered useful in 89.3% of cases, and a change of the surgical strategy was observed in 42.5% of cases. The agreement of nTMS-based planning and IONM-based strategy in 35 patients was 94.2%. A new permanent motor deficit occurred in 8.5% of cases (4 of 47). A higher resting motor threshold (RMT) and the lack of an intraoperative arachnoidal cleavage plane were the only independent predictors of a poor motor outcome (p = 0.04 and p = 0.02, respectively). Moreover, a higher RMT and perilesional edema also predicted the lack of an arachnoidal cleavage plane (p = 0.01 and p = 0.03, respectively). Preoperative motor status, T2 cleft sign, contrast-enhancement pattern, and tumor volume had no predictive value.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>nTMS-based motor mapping is a useful tool for presurgical assessment of rolandic meningiomas, especially when a clear cleavage plane with M1 is not present. Moreover, the RMT can indicate the presence or absence of an intraoperative cleavage plane and predict the motor outcome, thereby helping to identify high-risk patients before surgery.</jats:p></jats:sec>

From Neurosurgical Planning to Histopathological Brain Tumor Characterization: Potentialities of Arcuate Fasciculus Along-Tract Diffusion Tensor Imaging Tractography Measures

“…In the last few years, neuronavigator-integrated TMS (nTMS) has been used to identify seeding regions for DTI tractography for multiple tracts, including CTS and AF, thus improving the reliability of the DTI fiber reconstruction results (62)(63)(64)(65)(66)(67)(68). The association of these neurophysiological and neuroimaging techniques has notable advantages for reconstruction of subcortical language tracts such as the AF, which is affected by elevated intersubject anatomical variability in cortical projections (14), which can be accurately identified by nTMS, as recently shown by Giampiccolo et al (69).…”

Navigated Transcranial Magnetic Stimulation Motor Mapping Usefulness in the Surgical Management of Patients Affected by Brain Tumors in Eloquent Areas: A Systematic Review and Meta-Analysis

“…The gold standard for functional assessment and surgical planning is represented by DES associated with IONM (29)(30)(31)(32). With the aim to improve risk stratification of motor eloquent area detection in the preoperative phase, other techniques have been introduced.…”

“…In literature, several authors documented the positive influence of nTMS on surgical planning and postoperative outcome, with a significant role in risk stratification (26,27,31,45,61,62). Interestingly, and apparently in contrast to these data, some authors reported more postoperative neurological deficits, with delayed recovery.…”

Middle Frontal Gyrus and Area 55b: Perioperative Mapping and Language Outcomes

“…Direct electrical stimulation (DES) at the cortical and subcortical levels is the gold standard for intraoperative mapping, defining the functional borders of resection in glioma surgery (13)(14)(15). In addition, navigated transcranial magnetic stimulation (nTMS) has emerged over the past decade as a useful adjunct for the preoperative mapping of motor (16)(17)(18)(19)(20)(21) and language (22)(23)(24)(25)(26)(27) areas of the brain.…”