Preoperative fMRI, tractography and continuous task during awake surgery for maintenance of motor function following surgical resection of metastatic tumor spread to the primary motor area.

The goal of the present study was to determine the efficacy of preoperative fMRI, tractography, and intraoperative continuous task during awake surgery in preserving postoperative motor function in patients undergoing resection of metastatic brain tumors in or near the primary motor area. Three patients with metastatic brain tumors in the primary motor area elected to undergo surgical treatment. Preoperative fMRI and tractography were performed, and various primary motor areas (e. g., hand, arm, face and leg) were identified and confirmed by cortical mapping or by the outcome of awake surgery. Cortical mapping and continuous appropriate task were performed during awake surgery. Preoperative fMRI and tractography correctly identified the primary motor area. In contrast, cortical mapping identified the gyrus of the primary motor area but was unable to identify specific primary motor areas, such as those for the hand or arm, which were compressed by the tumor. Tumor resection was terminated when any deterioration in continuous task performance was observed during awake surgery. Paresis was transient and resolved within one week in all cases. The combination of preoperative fMRI, tractography and continuous task during awake surgery helped to maintain motor function following surgical management of metastatic brain tumors of the primary motor cortex.