NIMG-64. INTRAOPERATIVE LANGUAGE MAPPING USING GAMMA-BAND MODULATIONS OF ELECTROCORTICOGRAM (ECOG) INDUCED BY WORD/SOUND CATEGORIZATION TASK: VALIDATION WITH REPRODUCIBLE SPEECH ARRESTS DURING LINGUISTIC TASKS

Abstract OBJECTIVE Determination of the correlation between gamma-band modulations electrocorticogram (ECoG) induced by linguistic tasks and reproducible speech arrests caused bipolar direct cortical stimulations (DCS). METHODS 3 subjects (age 39, 56, 64 years) with left temporal lobe glioma underwent surgery involving awake craniotomy. A 4x8 ECoG electrode grid (2.3mm contact exposure, 1cm spacing) was placed above respective tumor area. MATLAB-Simulink based real-time software system running on a portable laptop computer used to map as 2D heat while engaged in different tasks: word/sound categorization pressing button, object naming, action written descriptive auditory naming. Auditory stimulus applied during task (duration 300 – 500ms), naming ( > 1s); other involved visual only. The repeated four DCS (2/4/6 mA, 60Hz, 2s) at pairs. RESULTS electrodes having stronger were distinct for tasks. Reproducible occurred object, action, stimulating specific pairs, even though not all these had strong activations Across consistently tasks, starting early 250ms lasting after stimuli terminated (~ 650ms). longer can be associated word recognition process. self-reported about difficulty comprehension rather than production arrests. 3D brain rendering using MRI images showed that arrest identically located superior gyrus, inferior central sulcus subjects. CONCLUSION Intraoperative language mapping guided utilized localize eloquent cortex processing.