A concussion is a type of traumatic brain injury (TBI) caused by forces from a bump, blow, or jolt to the head—sustained either directly or indirectly to the body (as in whiplash)—that disrupt normal brain functioning. These direct or indirect forces result in acceleration, deceleration, and/or rotation of the brain inside the skull and the initiation of a complex pathophysiologic process that alters neurometabolism. (1)