Management of concussion in collision sports.  Guidelines for the sidelines. 
During high-risk sports events, it is important for team physicians to be alert to the possibility of concussion in athletes who may not realize they have been injured or may want to conceal their injury.  If concussion is suspected and the player is conscious, history taking should include inquiries about loss of consciousness, loss of memory of events before and after the impact, headache, visual abnormalities, motor and sensory changes, and back, neck, and extremity pain.  In an unconscious player, the airway, breathing, circulation, and cervical spine should be checked.  The cervical spine must be stabilized before the player is moved if injury to it is suspected.  Athletes with such an injury and those who have lost consciousness require hospital evaluation.  If there is no cervical spine injury, a complete neurologic evaluation should be carried out on the sidelines and the player checked for signs of skull fracture.  The Colorado Medical Society guidelines for grading concussions and deciding when athletes may return to competition are an excellent aid to clinical judgment.