Jeffrey P. Feden, M.D., FACEP
The concussion epidemic has captured significant attention in the mainstream media and the sports medicine community over the past several years. On the heels of a landmark NFL settlement and growing concerns over chronic traumatic encephalopathy, the safety of American football has come under scrutiny. It should be no surprise, then, that the future of the sport is at a crossroads.
While our knowledge of concussion pathophysiology, treatment, and long-term consequences has developed rapidly over the past decade, the next decade will likely bring about exponential advances in technology aimed at preventing concussion, or at least better informing individual risk.
Current concepts: Where are we now?
The International Consensus Conferences on Concussion in Sport over the years (Vienna 2001, Prague 2004, Zurich 2008, and Zurich 2012) have laid the foundation for our present-day understanding of concussion and approach to management. (1) Concussion is a complex functional and microstructural brain injury resulting from specific biomechanical forces. An ensuing neurometabolic cascade leads to a variety of signs, symptoms, and behavioral and cognitive impairments that may last from days to months. Diagnosis is largely clinical but aided by widely available concussion assessment tools and computerized neurocognitive testing. Management of sports-related concussion has traditionally involved strict physical and cognitive rest, though the role of vestibular therapy and supervised, subsymptom threshold exercise programs are gaining acceptance.
While second-impact syndrome strikes fear in parents, the primary goal during acute recovery is to avoid re-injury within this period of increased vulnerability, as a second injury may amplify symptoms and complicate recovery. Once pre-injury cognitive function has returned and symptoms have abated, a program of graded exertion (e.g., return to play protocol) precedes the return competitive athletics. A minority of athletes will experience a prolonged recovery or post-concussion syndrome which may be associated with challenging psychosocial issues. Furthermore, chronic traumatic encephalopathy now weighs heavily on the minds of parents and athletes, though direct causation is yet to be proven.
Future directions: Preventing concussion
The risks of playing football and other contact sports are well-established, as are the numerous advantages of these athletic endeavors. However, moving forward, we must find a common ground between player safety and risk modification while still preserving the traditions and excitement of the game. This common ground will encompass many areas, including technological and scientific advances in equipment, diagnosis, risk stratification, and rule changes.
Despite an existing lack of scientific evidence that mouth guards, helmets, and other headgear can prevent concussion, significant effort continues to focus on the design of protective equipment for primary prevention. Exciting advances in helmet technology are being incorporated into prototypes such as the Zero1 helmet from Vicis (vicis.com) which is built with a flexible outer shell to reduce impact. Researchers such as Dr. Raymond Colello at Virginia Commonwealth University are thinking farther outside the box by using magnetic repulsion to reduce the force of collision. (2) Still others are outfitting helmets with accelerometers designed to measure and record the magnitude of collision force in real-time. While accelerometer study data remains limited, the cumulative effects of repetitive head impacts may increase risk the risk for neurological consequences in later life. (3) Closer monitoring of concussive and subconcussive (significant impact without clinical symptoms) blows, therefore, might prove valuable in better informing and mitigating long-term risks.
Technological advances further extend into the realm of diagnosis. Even after concussion has occurred, effective tools to provide a more complete and objective assessment of the injury and its clinical effects are highly desirable. Historically, the dependence on self-reporting (and under-reporting) of symptoms has made concussion diagnosis challenging. Legislative developments and injury awareness, as well as rule changes and league policies, have contributed to improved recognition and athlete safety. However, current tools for sideline and office diagnosis, such as the Sport Concussion Assessment Tool (version 3; SCAT3) and computerized neurocognitive testing, are limited in application and cannot be used in a stand-alone fashion. Development of other diagnostic tests, such as software applications and serum biomarkers, may improve our ability to more quickly and accurately diagnose concussions, remove athletes from competition, and enhance secondary prevention. Taken together with functional MRI, these tools could then allow for a more comprehensive picture of the injury course and a more precise determination of safe return to play.
Lastly, ongoing efforts in the legislative arena and continued education of athletes, parents, coaches, and officials remain the cornerstone of concussion prevention while other technologies evolve. Prevention, diagnosis, and management rely most heavily on education and awareness at the present time. While it is clear that concussions will always be a part of the sports that we love, it also seems clear that we are moving toward a variety of innovations that will feed into a risk algorithm whereby several measures will better inform athletes about individual risk. These athletes, along with their families and healthcare providers, can then make better educated decisions about if/when to return to sports following concussion. And perhaps such a model of risk stratification will be enough to save American football.
1. McCrory P, Meeuwisse WH, Aubry M, et al. Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, 2012. Br J Sports Med. 2013;47(5):250-8.
2. Baggaley K. (2014, November 15). Magnets in helmets might make football safer. Retrieved from https://www.sciencenews.org/article/magnets-helmets-might-make-football-safer. Accessed May 29, 2016.
3. Montenigro PH, Alosco ML, Martin B, et al. Cumulative head impact exposure predicts later-life depression, apathy, executive dysfunction, and cognitive impairment in former high school and college football players [published online March 30, 2016]. J Neurotrauma. 2016.