Human brain anatomy

Traumatic brain injury, often referred to as TBI, occurs when an accelerating or decelerating movement of the brain caused by a blow or jolt to the head causes damage to the brain. TBI can occur from hitting one’s head or having one’s head struck in a motor vehicle accident or during a fall, experiencing shock waves caused by an explosion, or an object penetrating the brain causes damage to the brain. Not every blow to the head causes a TBI and one does not have to lose consciousness to sustain a TBI.

The following generally accepted criteria for TBI is established by the TBI Model Systems (TBIMS), which were funded by the National Institute on Disability and Rehabilitation Research (NIDRR).

A person has suffered damage to the brain as a result of external force and at least one of the following has occurred:

  • A documented loss of consciousness
  • Inability to recall the actual traumatic event
  • The person has an abnormal brain scan or skull fracture, or has experienced a post-traumatic seizure due to the trauma

Brain injuries can range from mild to severe depending on the extent of injury. No two brain injuries are alike and the consequence of two similar injuries may be very different. The person with a mild TBI (mTBI) may not realize she has had a brain injury, though some persons with mTBI continue to have symptoms for several months or longer. A person with moderate or severe brain injury may expect recovery to continue over many months or years and even then may continue to experience a variety of symptoms. For more information on TBI, please visit http://www.cdc.gov/traumaticbraininjury/ or http://depts.washington.edu/uwtbi/.