10037-SPE-3 APPROACH TO SAFE AND RELIABLE BRAIN TUMOR SURGERY APPLYING INTRAOPERATIVE GAMMA OSCILLATION REGULARITY ANALYSIS

Abstract

In primary brain tumors, the complexity of Electroencephalogram (EEG) has been reported to be higher compared to healthy individuals. In gliomas, a significant decrease in gamma oscillation regularity in the tumor-surrounding brain cortex has been demonstrated. It is considered acceptable to remove the areas with significantly decreased gamma oscillation regularity as non-functional regions with deteriorated normal brain function. This article introduces the practical application of safe and reliable brain tumor surgery using an approach from non-functional regions through intraoperative analysis of gamma oscillation regularity. The patient had undergone a partial resection surgery for a left temporal lobe tumor at another hospital and was diagnosed with a glioblastoma. Upon transfer to our hospital, the patient exhibited mild motor aphasia but had good comprehension. Language dominance was determined to be on the left side through the WADA test. Approximately 50% of the tumor, which was enhanced near the Broca's area and Wernicke's area, remained after the first surgery. We performed a non-awake extraction surgery for the residual tumor using intraoperative analysis of gamma oscillation regularity. By depicting a non-functional field during the operation, almost all of the tumors to be contrasted were removed without exacerbation of symptoms. Since the non-functional field can be depicted intraoperatively, surgery can be performed safely even in patients who cannot tolerate awake surgery. Brain tumor surgery using intraoperative analysis of gamma oscillation regularity is considered highly beneficial.