Intraoperative Neurophysiological Monitoring During Adult Brainstem Glioma Resection: Association Between Electrophysiological Changes and Early Neurological Outcome
Simple Summary Adult brainstem gliomas are rare tumors located in one of the most functionally critical regions of the central nervous system. Surgical treatment carries a substantial risk of neurological injury, making intraoperative neurophysiological monitoring (IONM) an important tool for preserving neural function. In this retrospective study, we evaluated the association between intraoperative electrophysiological changes and early postoperative neurological outcomes in 22 adults who underwent surgical resection of brainstem gliomas. Somatosensory and motor evoked potential changes were frequently observed during surgery; however, conventional amplitude-based warning criteria were not associated with neurological status at hospital discharge. In contrast, increases in motor stimulation thresholds were significantly associated with postoperative complications. These findings suggest that dynamic changes in motor threshold may provide clinically relevant information beyond traditional amplitude-based monitoring parameters. Larger prospective studies are needed to confirm the prognostic value of specific IONM metrics and to optimize intraoperative monitoring strategies during brainstem glioma surgery.