 All prior ECoG recordings of SDs has relied on subdural electrode strips consisting of a linear array of electrodes placed over the cerebral cortex near contused brain tissue. This recordings strategy is adequate to capture SD events, however, it affords the ability to monitor a small area of the cortical surface. The small monitoring area imposed several limitations on previous studies. First, CSDs are captured within a limited distance of each recording electrode contact. CSDs that occur beyond the monitoring region are not recorded and, therefore, prior studies likely underestimate the true frequency of SD events after TBI. Second, the linear configuration of subdural strips does not provide adequate spatial information regarding the CSD waves to determine the origin or direction of propagation. Improved spatial resolution of the ECoG recordings in conjunction with appropriate analytic techniques will allow determination of the direction of SD wave propagation and possibly the identification of pathologic foci where SDs originate. Identification of where SDs originate will afford the ability to correlate these locations with imaging to determine the structural characteristics and pathology that give rise to this pathological phenomenon. 