With the New York Times having published 15 articles on concussion in the last year alone, sport concussions are clearly making national headlines at a record pace, and creating a much-needed awareness of this often-puzzling injury. The number of publications on sport concussion and mild traumatic brain injury in sports published from 2000 to 2006 has already surpassed the total number published from 1980 to 2000, and since 2000 there have been three international concussion consensus conferences, each involving international experts and each publishing consensus statements, as well as extensive documents from National Athletic Trainers' Association (NATA) and the American College of Sports Medicine (ACSM) on concussion management. Despite this, sport concussion still remains one of the most puzzling and mismanaged neurological conditions described in the sports medicine literature.
The proper management of a concussion involves several factors that must be taken into consideration. Factors include previous concussion history including number of concussions, proximity, and severity of concussions, the neurological examination with particular emphasis on cognition and balance testing, imaging studies if used, and neuropsychological testing if used.
I have had the good fortune to be a member of the writing groups for the three international concussion consensus documents as well as NATA's and ACSM's efforts. This commentary reflects that literature.
First and foremost, anyone who is still symptomatic from a concussion should not be allowed to return to a contact or collision sport, and, in fact, should have physical exertion curtailed. If intellectual exertion worsens symptoms, it must be limited as well. An athlete who, at the scene of a contest has symptoms after at least 20 min of rest, should be disqualified from returning to participation on the day of injury. Sideline exertional exercises that can be used to see if exertion provokes symptoms include sideline jogging followed by, if asymptomatic, sprinting. Sit ups, pushups, and other sports-specific noncontact activities that the athlete might perform on returning to participation also may be used. Male college or professional athletes over the age of 18 whose symptoms have abated in under 20 min at rest and exertion, and whose neurological examinations are normal, and whose past concussion history is benign may, in selected cases, be allowed to return to the contest. If there are anyuncertainties, the adage "if in doubt, sit them out" is definitely the safe one to follow. The rationale for allowing anyone to return to a contest after a concussion is that if an athlete knows that the mention of concussion symptoms means automatic removal from play for that day, they may bedeterred from reporting their symptoms to sideline medicalpersonal. For high school and younger athletes, recognition of a concussion should preclude return to the contest.
Athletes who experience loss of consciousness or amnesia should be disqualified from participating for the day. The decision to disqualify from further participation on the day of a concussion should be based on a comprehensive neurological examination, assessment of self-reported post concussion signs and symptoms, and the athlete's concussion history. Assessment tools such as the SAC, BESS, computer-based neuropsychological test batteries, and symptom checklist are all useful. It cannot be stressed enough that all tools must be normal or baseline before allowing an athlete to return to competition. No one tool can be used to determine return to play. A 7-d symptom-free wait period before returning to participation is recommended, especially for scholar athletes. Athletes with history of prior concussions are at increased risk for sustaining subsequent concussions, as well as for slowed recovery of self-reported post-concussion signs and symptoms, cognitive dysfunction, and postural instability. In athletes with three or more concussions and who are experiencing slowed recovery, temporary or permanent disqualification from contact sports may be indicated. It also is true that the effects of concussion in children and females appear to be different from male adults, with children and females having an extended period of neurocognitive recovery and greater susceptibility to concussion. It also is true that all cases of second impact syndrome, excluding those in boxing, have occurred in individuals younger than 18 years of age. Because of this, it is prudent to treat younger athletes and females more conservatively.
It is generally accepted that three mild concussions in any one season should terminate an athlete's further participation that season. Furthermore, there should be at least a 3-month symptom-free period before resuming participation in a contact collision sport. It is further recommended for any athlete whose neurological examination has not returned to normal, or if they have any post-concussion signs or symptoms either at rest or exertion, that further participation is contraindicated. Additional criteria that would preclude return to competition would include a neuropsychological test battery that does not return to baseline or above, or imaging studies that show a lesion placing the athlete at increased risk of future head injury.
An additional criterion used in disqualifying an athlete from further contact or collision sport participation, especially athletes with a history of more than three concussions, is when the time to recovery progressively increases with subsequent concussions. This is especially applicable when such post-concussion symptoms last 3 months or more. Also the severity of the blow that produced the concussion is used by many to determine whether an athlete should consider retirement. Impulsive loading of acceleration forces to the brain from a blow to another body part that produces prolonged post-concussive symptoms is a worrisome finding that would lead many to suggest an athlete retire from a contact or collision sport.
In conclusion, the brain and spinal cord are unique, because once cells die, they are incapable of regeneration, and replacement is not possible. Thus injuries to the brain are of singular importance. Athletes must never play while symptomatic. Before return is considered, the athlete must be asymptomatic at rest and then with maximal exertion. To play while symptomatic is to risk prolonged post-concussion syndrome, chronic traumatic encephalopathy, and even death.