The outcome of brain injury (physical or stroke) may be related to a brain electrical phenomenon known as Cortical Spreading Depression (CSD). This is a brief cessation of function in a local region of brain tissue. It has been hypothesized that CSD may occur after brain injury and may expand the damage to adjacent brain areas. Our aim is to detect CSD by means of intracranial electrodes in patients with brain injuries and asses how these events alter the outcome of the patients.