Traumatic Brain Injury

Abstract
Traumatic brain injury (TBI) is a multifaceted condition, not an event. Traumatic brain injury is broadly defined as an alteration in brain function or other evidence of brain pathology caused by an external force that can occur in traffic, at home, at work, during sports activities, and on the battlefield. Traumatic brain injury is an important cause of death and disability for children and an exponentially increasing source of morbidity and mortality in older adults.1 Each year in the United States, at least 1.7 million people seek medical attention for TBI; it is a contributing factor in a third of all injury-related deaths.2 Many more persons, particularly those with mild TBI, are never seen by a clinician. These injuries (at times considered to be “concussions”) are often dismissed by the medical community as mild with few or no consequences. Although no single definition of concussion is widely accepted, it typically affects orientation, memory, and may involve loss of consciousness.3 Often, patients are not carefully followed up over time, despite the increasing appreciation that TBI can affect long-term physical, cognitive, emotional, and social domains of function. The Centers for Disease Control and Prevention estimates that 2% of the US population lives with disabilities directly attributable to TBI,2 with annual direct and indirect costs estimated at more than $76.5 billion.1