brain concussion [AS, bragen + L, concussus, a shaking] , a bruising to cerebral tissues caused by a violent jarring or shaking or other blunt, nonpenetrating injury to the brain resulting in a sudden change in momentum of the head. Characteristically, after a mild concussion there may be a transient loss of consciousness followed, on awakening, by a headache. Severe concussion may cause prolonged unconsciousness and disruption of certain vital functions of the brainstem, such as respiration and vasomotor stability. The treatment for a person recovering from a concussion consists principally of observation for signs of intracranial bleeding and increased intracranial pressure. Also called concussion.
