CONCUSSION

a period of paralysis of nervous function resulting from a relatively mild injury to the brain, not necessarily associated with cerebral hemorrhage, contusion, or laceration. Unconsciousness caused by concussion usually lasts less than 5 minutes and rarely more than 10. In some cases there may be a long-continued disturbance of consciousness, with some residual symptoms. Amnesia always accompanies concussion. Recovery from simple, uncomplicated concussion is almost always complete.