1. Moderate to severe traumatic brain injury, defined as one or more of the following: penetrating head wound seizure within the first hour after injury intracerebral hematoma or cortical contusion subdural or epidural hematoma Glasgow Coma Score <= 12 or motor score 1-5 (if intubated). Patients who have been pharmacologically paralyzed will be evaluated after the paralytic has worn off or been pharmacologically reversed depressed skull fracture requirement for emergent neurosurgical procedure