A contusion is a type of traumatic brain injury (TBI) that causes bruising of the brain tissue; a hematoma is heavy bleeding into or around the brain. The severity of a TBI can range from a mild concussion to the extremes of coma or even death.
Each year, minor incidents of TBI happen to over one million people in the United States. These minor injuries result in the treatment and release from hospital emergency departments. Another 230,000 people are hospitalized each year with TBI. Of these people, 99,000 will show a lasting disability.