STMO-14 VALIDATION OF SURGICAL METHODS FOR GLIOMA AROUND THE MOTOR CORTEX

Abstract

Abstract Surgery for glioma around the primary motor area (primary MA) including premotor area (PA) and supplementary motor area (SMA) is performed by general anesthesia with motor evoked potential, called asleep surgery (Asleep S) or awake surgery (Awake S). The literature has shown that there is no difference in tumor removal rate and preservation of neurological function between the two methods. We retrospectively studied 14 patients who underwent craniotomy for glioma of the frontal lobe at our hospital, and 19 surgeries with contrast-enhancing lesions or T2 high-signal areas in the motor area. Tumor primary location was PMA: 6, PMA/ primary MA: 5, primary MA: 2, SMA 6 surgeries. All surgeries identified central sulcus by SEP and monitored transcranial and transcortical MEP. 11 surgeries were Asleep S and 8 were Awake S. Of the 11 Asleep S surgeries, 10 were high grade glioma with contrast on preoperative imaging. Of the 8 Awake S surgeries, 7 were lower grade gliomas, and most of these surgeries were performed for multiple recurrences. In Awake S, difficulties of assessment of motor function arose when the PMA and SMA were removed early in the surgery. In the case of Asleep S, to clarify the criteria for MEP warning signs is necessary, while in Awake S, the knowledge that how much motor decline is tolerated in voluntary movements need. In the case of Asleep S, to clarify the criteria for MEP warning signs is necessary, while in Awake S, the knowledge that how much motor decline is tolerated in voluntary movements need. In addition, the order of resection to avoid SMA syndrome and to evaluate motor function is important. We summarize the literatures and discuss these points for surgical strategy in glioma around motor area.