Role of Asleep Surgery for Supplementary Motor Area Tumors

Background The supplementary motor area (SMA) is involved in planning of voluntary motor activities. Tumors in SMA usually present with seizures and, rarely, motor deficits. Postoperatively, these patients may develop SMA syndrome. Patients with SMA tumors usually undergo awake craniotomy along with neuromonitoring for maximal safe resection, and some of these patients tend to have residual tumor. Objective To completely excise the SMA region tumors under general anesthesia without causing any permanent neurological deficits. Methods We operated upon four patients with SMA region tumor under general anesthesia (GA) with direct electrocortical stimulation (DES). Motor-evoked potential was used to monitor corticospinal tracts through corkscrew or strip electrodes. Intraoperative MRI was done to assess the tumor excision. Results All four patients had complete resection of tumor and, postoperatively, all four developed SMA syndrome. All of them recovered completely over a period of time. Conclusion SMA tumors can be excised completely under GA with DES, thereby increasing progression-free survival.