Oct. 1, 2004
Kevin Guskiewicz, Ph.D., ATC
Professor and Director, Sports Medicine Research Laboratory
University of North Carolina
Sport in today's society is more popular than probably ever imagined. Large numbers of athletes participate in a variety of youth, high school, collegiate, professional, and recreational sports. It is not that unusual for a young boy or girl to attempt to throw, kick, or hit a ball long before they ever attempt some of the more essential life functions such as grasping a fork, writing their name, or tying a shoe. We are a sport-crazed society. For the younger participants, the sport experience provides an environment in which they can grow and develop physically, mentally, emotionally, and socially. With public health concerns such as increasing incidences of obesity, cardiovascular disease, and diabetes, it is becoming more important to encourage today's youth to find physical activities that are enjoyable, and can be retained as lifelong activities aimed at maintaining a healthy lifestyle.
As sport becomes more of a fixture in the lives of young Americans, a burden of responsibility falls on the shoulders of the various sporting organizations, coaches, parents, clinicians, officials, and researchers, to provide an environment that minimizes the risk of sport-related injury. Being able to identify serious injuries such as a cerebral concussion, which have the potential to become life-altering, is critical to the safety of athletes. Creating an awareness of the potential dangers of playing while still symptomatic from a cerebral concussion is equally important.
Cerebral concussion can best be classified as a mild diffuse injury and is often referred to as mild traumatic brain injury (MTBI). A concussion was characterized at the First International Conference on Concussion in Sport as follows:
1) Concussion may be caused by a direct blow to the head or elsewhere on the body from an "impulsive" force transmitted to the head.
2) Concussion may cause an immediate and short-lived impairment of neurologic function.
3) Concussion may cause neuropathologic changes; however, the acute clinical symptoms largely reflect a functional disturbance rather than a structural injury.
4) Concussion may cause a gradient of clinical syndromes that may or may not involve loss of consciousness. Resolution of the clinical and cognitive symptoms typically follows a sequential course.
5) Concussion is most often associated with normal results on conventional neuroimaging studies.
The injury involves an acceleration-deceleration mechanism in which a blow to the head or the head striking an object results in one or more of the following conditions: headache, nausea, vomiting, dizziness, balance problems, feeling "slowed down," fatigue, trouble sleeping, drowsiness, sensitivity to light or noise, loss of consciousness, blurred vision, difficulty remembering, or difficulty concentrating.
Occasionally, players sustain a blow to the head resulting in a stunned confusional state that resolves within minutes. The colloquial term "ding" is often used to describe this initial state. However, the use of this term is not recommended because this stunned confusional state is still considered a concussion resulting in symptoms, although only very short in duration, which should not be dismissed in a cavalier fashion. It is essential that this injury be reevaluated frequently to determine if a more serious injury has occurred, because often the evolving signs and symptoms of a concussion are not evident until several minutes to hours later.
Although it is important for the clinician to recognize and eventually classify the concussive injury, it is equally important for the athlete to understand the signs and symptoms of a concussion, as well as the potential negative consequences (i.e., second-impact syndrome, predisposition to future concussions, etc) of not reporting a concussive injury. Once the athlete has a better understanding of the injury, he or she can provide a more accurate report of the concussion history.
Concussion in Soccer
Soccer, undoubtedly the fastest growing youth sport in the United States, has been considered a safe sport for many years, and it should still be considered a safe sport. The lay press and news media have in some respect helped to create more of an awareness of the dangers related to participating in sport while still experiencing symptoms from an initial head injury. Today's athletes, parents, and coaches are probably more aware than ever of the serious consequences associated with second impact syndrome - a catastrophic head injury that typically occurs within 7 days of an initial concussion for which the symptoms have not resolved. This welcomed awareness will likely save lives in the long run. However, there is still a lot to be learned about whether repetitive, subconcussive impacts from soccer result in significant brain injury and long-term complications.
A unique aspect of the game of soccer is the purposeful use of the unprotected head for controlling and advancing the ball. Some studies of high-level amateur and professional European soccer players suggest that extended exposure to the game may be associated with chronic cognitive impairments. Recent research has refuted these findings in American soccer players, suggesting that there are no long term effects of playing soccer, or for that matter, heading a soccer ball.
There has been no published study that has provided direct evidence that the practice of heading a soccer ball causes long-term deficits in neurological or neuropsychological function. What does appear to be evident is that elite European players, with extensive soccer exposure, demonstrated mild deficits on a few select tests that were conducted. Those test results suggest that these players are slower at learning and remembering new material that they hear or see. These players score normal on the majority of the neuropsychological tests conducted. In contrast to the European studies, every study that has been conducted involving American soccer players has revealed no deficits on tests of neuropsychological functioning or intelligence.
Epidemiological studies reveal that soccer players are at a risk for sustaining a concussion, much like youth participants in gymnastics, wrestling, football, skateboarding, and bicycling. In terms of catastrophic injuries, soccer ranks well below most of these sports. The game of soccer has been played internationally for over a century without the use of headgear, and the absence of increasing catastrophic outcomes from participating in soccer suggests that it is a relatively safe sport in terms of severe trauma to the head and neck. Recent research findings indicate a greater incidence of concussion and self-reported previous concussions in soccer players than previous thought. The question still remains as to whether rules should be modified, especially for the very young, unskilled player, to limit heading exposure.
Headgear has been advocated as a potential intervention strategy. However, it has not been studied well enough to determine if it will decrease the degree of impact of the ball, much less the likelihood of sustaining a concussion during soccer participation. Concern has even been raised that headgear could potentially lead to injury. Others have argued the risk-homeostasis theory, claiming that mandating soccer headgear could make it a more aggressive game by giving players a false sense of invulnerability. Adding extra weight to the heads of these young players may be detrimental. If the muscles are not strong enough to hold the head up for proper heading techniques, they could be even more predisposed to head and/or neck injuries. Quite frankly, it is entirely too early in the game to mandate headgear for soccer players at any level of play.
One positive outcome from the recent flurry of attention surrounding heading and head injury in soccer is that it has focused attention on concussion in sport, and youth sport in particular. Both the acute short-term effects and the chronic long-term sequelae of concussion are surprisingly poorly understood. More comprehensive methods for the assessment and management of concussion, such as neuropsychological and postural stability testing, are indicated for all athletes participating in sports with a high risk for cerebral concussion.
In recent years, new scientific research and clinical-based literature have given the athletic training and medical professions a wealth of updated information on the treatment of sport-related concussion. To provide certified athletic trainers, physicians, other medical professionals, parents, players, and coaches, with recommendations based on these latest studies, the National Athletic Trainers' Association (NATA) recently issued a new position statement - "Management of Sport-Related Concussion" - in the September/ October 2004 issue of The Journal of Athletic Training. The full text and complete reference list for this peer reviewed position statement is also available at http://www.pubmedcentral.nih.gov and http://www.nata.org/publicinformation/position.htm. Below are some of the highlights that should be considered in the management of sport-related concussion:
Defining & Recognizing the Concussion
Evaluating and Making the Return-to-Play Decision
Concussion Assessment Tools
When to Refer to a Physician
When to Disqualify
Special Considerations for Young Athletes
REFERENCE: Guskiewicz KM, Bruce SL, Cantu RC, Ferrara M, Kelly JP, McCrea M, Putukian M, Valovich McLeod, TC. National Athletic Trainers' Association position statement: Management of sport- related concussion. J Athl Train. 2004;39:280-297.