Traumatic brain injury (TBI), a form of acquired brain injury, occurs when a sudden trauma causes damage to the brain. TBI can result when the head suddenly and violently hits an object, or when an object pierces the skull and enters brain tissue.  Symptoms of a TBI can be mild, moderate, or severe, depending on the extent of the damage to the brain.  TBI is a major cause of death and disability worldwide, especially in children and young adults.

CDC estimates that at least 5.3 million Americans, approximately 2% of the U.S. population, currently have a long-term or lifelong need for help to perform activities of daily living as a result of a TBI. 1.4 million individuals in the U.S. sustain a TBI each year. Among children ages 0 to 14 years, TBI results in an estimated 2,685 deaths and 435,000 emergency department visits in the United States annually.

Disabilities resulting from a TBI depend upon the severity of the injury, the location of the injury, and the age and general health of the individual. TBI can cause a wide range of functional changes affecting thinking, sensation. Some common disabilities include problems with cognition (thinking, memory, and reasoning), sensory processing (sight, hearing, touch, taste, and smell), communication (expression and understanding), and behavior or mental health (depression, anxiety, personality changes, aggression, acting out, and social inappropriateness).