A “traumatic brain injury” is an injury to the brain that disrupts its function. The Brain Injury Association of America defines it as “an alteration in brain function, or other evidence of brain pathology caused by an external force”. A “mild” traumatic brain injury involves a brief or no loss of consciousness. The individual may seem dazed or confused at the time of the injury. Symptoms may include headache, irritability, sleep disturbance, fatigue, memory issues or depression. The symptoms may last for days or persist for extended periods. A “moderate” traumatic brain injury involves a loss of consciousness from a few minutes to a few hours. The individual may experience confusion which lasts for days to weeks. Impairments of behavior, cognition and physician abilities may last for months or become permanent. A “severe” traumatic brain injury typically involves extended periods of unconsciousness lasting days to weeks. Victims of severe traumatic brain injury may make some recovery, but they typically suffer significant permanent impairments.