Association of motor deficits with head position during awake surgery for resection of medial motor area brain tumors

Objective: Resection of tumors involving the motor area frequently results in postoperative motor deficits. In an attempt to prevent poor motor outcomes, our institution has utilized pre-operative fMRI and tractography as well as intraoperative cortical mapping and continuous motor tasks during awake surgery in patients with motor area tumors. In one case, a patient demonstrated deterioration in continuous motor task performance before initiation of tumor resection. Thus, the goal of this study was to evaluate the relationship between head position and development of intraoperative or postoperative motor deficits in five patients with motor area tumors. Clinical Presentation: In four cases, the patient's head was rotated 60 degrees from the supine position. In two cases, in which the tumor was located relatively medially, deterioration in continuous motor task function was noted prior to resection of the tumor. In the two other cases, in which the tumor was located relatively laterally, there was no deterioration of continuous motor task performance until resection of the tumor. Another patient, in whom the tumor was located relatively medially, underwent surgery with the head positioned straight and with the patient in a half-sitting position. This patient did not experience deterioration of continuous motor task performance during the surgery. Conclusion: These data suggest that head positioning can have a significant impact on motor function in patients with motor area tumors. Furthermore, the straight head position may be the preferred positioning, particularly for patients with tumors located on the medial side of motor area.