http://www.cdc.gov/node.do?id=0900f3ec8000dbdc
Centers for Disease Control and Prevention, U.S. Department of Health and Human Services
A traumatic brain injury (TBI) is caused by a blow or jolt to the head or a penetrating head injury that disrupts the normal function of the brain. This document discusses TBI, including causes, signs and symptoms, long-term outcomes, and costs.