- Evidence of severe traumatic brain injury (TBI) as defined by ANY one of the following: Known non-survivable head injury or open brain injury; Known AIS (head region) ≥ 4 by an appropriate imaging methodology; Contemplated CNS surgery; Abnormal physical exam indicative of severe CNS or any spinal cord injury above T5 level; or Glasgow Coma Score (GCS) = 3, 4 or 5.