Traumatic brain injury (TBI) is a significant healthcare concern in the US, affecting 1.7 million individuals each year. There are approximately 1,365,000 emergency department visits each year for TBI, which equates to 3,740 per day. Of these, approximately 75% are the results of concussion and other forms of mild TBI. Falls are the leading cause of TBI, and motor vehicle accidents the leading cause of TBI related deaths. Most traumatic brain injuries result in widespread damage to the brain because the brain ricochets inside the skull during the impact of an accident. The direct medical costs and indirect costs of TBI, such as lost productivity, totaled an estimated $60 billion in the US for the year 2000 (Source: US Department of Health and Human Services, Centers for Disease Control and Prevention, 2010).

TBI can significantly affect cognitive, physical, and psychological skills. Physical deficits can include problems with ambulation, balance, coordination, fine motor skills, strength, and endurance. Cognitive deficits of language and communication, information processing, memory, and perceptual skills are common, and psychological status is often altered.

Brain injury can occur in many ways. TBI typically result from accidents or sports injuries in which the head strikes an object. These are the most common types of TBI. However, other brain injuries, such as those caused by insufficient oxygen, poisoning, or infection, can cause similar deficits.

Mild TBI (MTBI) is often caused by concussion and characterized by one or more of the following symptoms: a brief loss of consciousness, loss of memory immediately before or after the injury, any alteration in mental state at the time of the accident, or focal neurological deficits. In many MTBI cases, the person seems fine on the surface, yet continues to endure chronic functional problems. Some people suffer long-term effects of MTBI, known as post-concussion syndrome (PCS). Persons suffering from PCS can experience significant changes in cognition and personality. Recent studies suggest that repeated TBI or MTBI has serious consequences to individuals later in life.


Currently, the Glasgow Coma Scale (GCS) is a numerical scale widely used clinically to assess coma and impaired consciousness. Persons with GCS scores of 3 to 8 are classified with a severe TBI, those with scores of 9 to 12 are classified with moderate TBI, and those with scores of 13 to 15 are classified with mild TBI. Other classification systems include the Abbreviated Injury Scale (AIS), Trauma Score, and the Abbreviated Trauma Score.

Concussion grading scales include the Cantu guidelines. Three grades are described, with grade I an injury associated with no loss of consciousness and less than 30 minutes of post-traumatic amnesia. This is the most common type of concussion by this guideline. In grade II the patient loses consciousness for less than 5 minutes or experiences amnesia for between 30 minutes and 24 hours. In grade III, the patient loses consciousness longer than 5 minutes and amnesia lasting longer than 24 hours. The patient may also exhibit signs or symptoms lasting over 1 week. More than one grade III concussion during a professional or collegiate athlete’s career may lead to recommendation that the player cease playing the sport.

A computerized concussion evaluation system was more recently developed call ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) that has been implemented by many sports teams. ImPACT is a 20-minute test that assists the clinician in making decision regarding the extent of the concussion injury and when the player can return to the sport activity. It measures attention span, working memory, sustained and selective attention time, response variability, non-verbal problem solving, and reaction time.