Functional Monitoring for Motor Pathway in Brain Tumor Surgery Within Eloquent Area

Clinical Efficiency of Motor Pathway Mapping Using Diffusion Tensor Imaging Tractography and Intraoperative Subcortical Stimulation in Cerebral Glioma Surgery

Resection of brain tumors in eloquent areas involves the risk of postoperative motor deficits. For brain tumors within or adjacent to the eloquent area, maximizing tumor resection while preserving motor function is crucially important.we used DTI-based tractography to visualize the spatial relationship between brain lesions and the nearby pyramidal tract(PT) in patients with malignant brain tumors and confirmed functional connections of the illustrated PT by direct electrical stimulation. We evaluated the reliability of DTI-based tractography for PT mapping using intraoperative subcortical stimulation ) and the usefulness of the combination of two techniques.

Adverse effects caused by electrical stimulation during the operation were recorded. All subjects adopted early postoperative MRI examinations (within 3 days) to evaluate both the extent of tumor resection and the integrity of the PTs. Muscle strength was assessed preoperatively and postoperatively.The Karnofsky Performance Scale (KPS) was adopted for grading functional status at the 6-month evaluation. Further tumor progression interval and survival analysis was conducted for each subject with high-grade glioma (HGG)

Inclusion Criteria:

• patients with an initial imaging diagnosis of single, unilateral, supratentorial primary glioma (or intrinsic neoplasm).
• The lesions were involved in PTs, comprising cortical regions in the motor or somatosensory areas, cortical regions adjacent to the central gyrus, subcortical regions with an infiltrative progression along the PTs, and temporal or insular regions in relation to the internal capsule.
• MRI enabled preoperative identification of patients in whom maximal tumor resection was likely to be achieved, and close PT approach within resection cavity at the time of surgery was possible.

Exclusion Criteria:

• patients with secondary or recurrent gliomas (or intrinsic neoplasm), patients with contraindications for MRI or direct electrical stimulation, and patients in whom initial muscle strength grades of the affected extremities was 2/5 or lower.