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Abstract BackgroundElectrocorticography (ECoG) language mapping is often performed extraoperatively, frequently involves offline processing, and relationships with direct cortical stimulation (DCS) remain variable. We sought to determine the feasibility and preliminary utility of an intraoperative language mapping approach guided by real-time visualization of electrocorticograms. MethodsA patient with astrocytoma underwent awake craniotomy with intraoperative language mapping, utilizing a dual iPad stimulus presentation system coupled to a real-time neural signal processing platform capable of both ECoG recording and delivery of DCS. Gamma band modulations in response to 4 language tasks at each electrode were visualized in real-time. Next, DCS was conducted for each neighboring electrode pair during language tasks. ResultsAll language tasks resulted in strongest heat map activation at an electrode pair in the anterior to mid superior temporal gyrus. Consistent speech arrest during DCS was observed for Object and Action naming tasks at these same electrodes, indicating good correspondence with ECoG heat map recordings. This region corresponded well with posterior language representation via preoperative functional MRI. ConclusionsIntraoperative real-time visualization of language task-based ECoG gamma band modulation is feasible and may help identify targets for DCS. If validated, this may improve the efficiency and accuracy of intraoperative language mapping. 

Background:Tumors infiltrating the precentral gyrus remain a unique operative challenge. In this study, we explored a novel approach for awake craniotomy involving a patient playing a drum pad during resection of low‐grade glioma, with the use of preoperative navigated transcranial magnetic stimulation (nTMS)–generated diffusion tensor imaging (DTI) and high‐density real‐time electrocorticography (ECoG). Observation:A 36‐year‐old left‐handed male with a low‐grade glioma in the left hemisphere hand knob region had a grand mal seizure. We combined preoperative nTMS‐DTI with intraoperative passive functional mapping using high‐density real‐time ECoG. During an awake craniotomy, the patient played a drum pad while we assessed somatosensory‐evoked potentials (SSEPs) using a 64‐channel ECoG grid. This confirmed the absence of motor‐evoked potentials (MEPs) over the tumor area, consistent with nTMS findings. Continuous monitoring of the patient’s drum pad performance during the resection allowed for a gross total resection (GTR) of the tumor. Following the resection, he experienced some weakness in the intrinsic muscles of his right hand, which returned to full normal function at 6 months. At the end of 1 year, he remained seizure‐free. Conclusion:A multimodal mapping strategy combined with awake monitoring of drum playing enabled preservation of function while achieving GTR in a patient with a motor‐eloquent glioma.