Detection of Hemodynamic Changes in TBI Population With Functional Near Infrared Spectroscopy

Inclusion Criteria: - Able to read, write, speak and understand English - history of having sustained a TBI prior to enrollment. Evidence will be any one of the following 3 criteria: 1. GCS 3 - 12 2. Post-traumatic amnesia > 24 hours 3. TBI-related abnormality on neuroimaging (either CT or MRI). (Some missing information about the initial injury (i.e. documentation of initial GCS) is not necessarily exclusionary if the bulk of the available history is indicative that the patient suffered a TBI and meets the inclusion criteria) Exclusion Criteria: - Multiple sclerosis, pre- or co-existing - Stroke (other than stroke at the time of TBI) - Pre-existing developmental disorder - Pre-existing epilepsy - Pre-existing major depressive disorder - Pre-existing schizophrenia