A traumatic brain injury or TBI can most easily be defined as a force to the head or brain resulting in a disruption in the proper functioning of the brain. A direct blow to the head is not required to injure the brain. A traumatic brain injury can be causes by a bump, blow, or a jolt to the head. The trauma or injury can dramatically disrupt the brain’s ability to function. Micro injuries to the brain cells can be permanent and can result in permanent deficits. The severity of a brain injury can range from mild to severe.