Incidence and clinical evolution of postoperative deficits after volumetric stereotactic resection of glial neoplasms involving the supplementary motor area.

OBJECTIVE: We report the incidence and clinical evolution of postoperative deficits and supplementary motor area (SMA) syndrome after volumetric stereotactic resection of glial neoplasms involving the posterior one-third of the superior frontal convolution. We investigated variables that may be associated with the occurrence of SMA syndrome.
METHODS: The postoperative clinical status of 27 consecutive patients who underwent resection of SMA gliomas was retrospectively reviewed. Neurological examination results were recorded 1 day, 1 week, 1 month, and 6 months postoperatively. The extent of tumor resection, the percentage of SMA resection, violation of the cingulate gyrus, and operative complications were tabulated.
RESULTS: The overall incidence of SMA-related deficits was 26% (7 of 27 patients), with 3 patients having complete SMA syndrome and 4 patients having partial SMA syndrome. Two additional patients (7.5%) had other postoperative deficits, including one with mild facial weakness and one with transient aphasia. The resection of low-grade gliomas was associated with a higher incidence of SMA syndrome, an outcome that likely reflects more complete removal of functional SMA cortex in this subset of patients. Intraoperative monitoring localized the precentral sulcus within the preoperatively defined tumor volume in 6 (22%) of 27 patients, thereby precluding gross total resection. All 27 patients had excellent outcomes at the 6-month follow-up examination.
CONCLUSION: When the resection of SMA gliomas is limited to the radiographic tumor boundaries, the incidence and severity of SMA syndrome may be minimized. With the use of these resection parameters, patients with high-grade SMA gliomas are unlikely to experience SMA syndrome. These findings are helpful in the preoperative counseling of patients who are to undergo cytoreductive resection of SMA gliomas.