Electrocorticography in Mapping Functional Brain Areas During Surgery in Patients With Brain Tumors

PRIMARY OBJECTIVE: I. To record electrocorticogram (ECoG) data intraoperatively with surface electrode grids during various motor, sensory (tactile) and speech tasks, and identify functional brain areas through the spectral analysis, and compare the preliminary data with our current pre-surgical mapping methods: functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS), and the gold standard, intraoperative direct electrical stimulation (DES). SECONDARY OBJECTIVE: I. To perform a preliminary assessment of the utility of using ECoG data in these patients to quantify new neurological and language/speech deficits in the short term (24 hours) and long-term (1, 3, and 6 months), and achieve a safe maximal tumor resection. OUTLINE: Patients undergo tumor resection. During surgery, patients also undergo electrocorticography with either the CorTec high resolution hybrid grid, the PMT high-resolution grid, or the Ad-Tech grid followed by direct electrocortical stimulation. Following completion of study, patients are followed up within 24 hours from surgery and at 1, 3, and 6 months.