Detection of After-discharges during Intraoperative Functional Brain Mapping in Awake Brain Tumor Surgery Using a Novel High-density Circular Grid

Abstract Objective To evaluate intraoperative use of a novel high-density circular grid in detecting after-discharges (AD) on electrocorticography (ECoG) during functional brain mapping (FBM). Methods FBM during glioma surgery (10/2016 to 5/2019) recorded ADs using a 22-channel circular grid compared to conventional strip electrodes. ADs were analyzed for detection, duration, amplitude, morphology, histology, direction, and clinical signs. Results Thirty-two patients (mean age 54.2 years; r = 30–75) with glioma (WHO grade II-IV; 20 grade IV) had surgery. ADs during FBM were more likely in patients with wild-type as opposed to IDH-1 mutants (p  Conclusions High-density circular grids detect ADs in 360 degrees during FBM for glioma resection. Provocation of ADs was more likely in patients with wild-type than IDH-1 mutation. Significance Circular grids offer high-resolution ECoG during intraoperative FBM for detection of ADs.