The Weight of Eloquence in Motor Area Glioblastoma: Oncologic Outcome After nTMS-Guided Surgical Resection.

BACKGROUND: Glioblastomas (GBMs) in eloquent areas, particularly within the motor system, represent a significant surgical challenge due to the risk of postoperative neurological deficits. This study evaluates the effectiveness of a structured preoperative protocol, including nTMS-guided motor mapping, to optimize surgical outcomes and minimize neurological deficits, with a particular focus on the timing of adjuvant oncological therapy initiation. METHODS: A retrospective analysis was conducted on 44 GBM patients, divided into two groups: 11 with motor area lesions (group A) and 33 with non-eloquent lesions (group B). All patients underwent a standardized preoperative protocol. Surgical outcomes (EORs), neurological function (MRC score and KPS index), time to oncological therapy initiation and survival (OS and PFS) were compared between groups. RESULTS: Both groups achieved high rates of GTR without significant differences in EOR (72.7% group A vs. 78.8% group B). Although group A exhibited a higher incidence of postoperative motor deficits, motor function at three-month follow-up was similar between groups. Time to initiation of oncological therapy did not differ between groups (40.6 days group A vs. 41.9 days group B, p = 0.719), highlighting that preservation of motor function helped minimize delays in starting oncological therapy. No significant differences were found in survival outcomes. CONCLUSIONS: A structured preoperative protocol incorporating nTMS motor mapping allows for safe and aggressive resection of motor-area GBMs. This approach effectively mitigates the risk of delays in initiating adjuvant oncological therapy, optimizing the patient prognosis. Further studies are needed to explore the long-term benefits of this protocol in both functional and oncological outcomes.