Concussion Study

The Varsity Athlete Concussion Research Project: A University of Toronto & Toronto Rehabilitation Institute Collaboration

Background
Concussions in sport continue to plague players, coaches, and sport medicine personnel with difficult questions about return to play. With professional-athletes, such as Eric Lindros, recently sidelined by concussion, the issues about recovery from head trauma has become increasingly publicized. A cerebral concussion is, by consensus definition, a mild traumatic brain injury (MTBI) in which there has been a traumatically induced alteration of consciousness that does not necessarily involve a loss of consciousness (c.f., Barth, 1989; Kelly, 1991, 1999; Esselman, 1995; American Academy of Neurology, 1997). Unfortunately, concussions in sport often go undiagnosed for a variety of reasons (e.g. athletes who do not want to risk loss of playing time do not report symptoms). Moreover, there is a lack of consensus regarding when it is appropriate for an athlete to return to play following a concussion, partially because of inadequate methods for diagnosing concussion and for determining when symptoms of concussion have fully resolved. These issues require our serious attention because of the growing body of knowledge concerning the consequences of returning to play too early following a concussion (Collins, Lovell, and McKeag, 1999; Echemendia, 1999) and of returning to play following multiple concussions (Collins et al, 1999).

MTBI not only affects athletes but also many Canadians who are injured in the workplace, at home or as a result of motor vehicle or bicycling accidents. Following a concussion, it is common for the injured person to report post-concussive symptoms, such as headache, dizziness, loss of coordination/or balance, irritability and possibly cognitive failures. Collection of pre- and post-injury data from a group of individuals at-risk for concussion, through sport, provides the opportunity to assess recovery patterns of cognitive functioning and to make comparisons to pre-injury functioning. One of the difficulties in assessing recovery from MTBI is that there is typically no information about premorbid functioning, and so, one has difficulty discerning the extent to which MTBI implicates existing cognitive deficits.

The U of T/Toronto Rehab group has developed a program of research that employs neuropsychological testing as the 'gold standard' for diagnosis of concussion and for determining when symptoms of concussion have resolved. The program includes the following research objectives:

• to validate a protocol for the assessment of post-concussive deficits
• to empirically validate return to play guidelines
• to better understand the pattern of recovery from concussion in previously concussed individuals
• to examine the rate of cognitive and emotional recovery from concussion
• to elucidate factors that contribute to protracted recovery from concussion.

In addition, a long-term clinical objective is the baseline neuropsychological testing of all athletes at risk for concussion in order to allow for a more conclusive diagnosis of concussion in athletes who sustain a blow to the head.

Resources The research team includes two professors from the University of Toronto's Faculty of Physical Education and Health:

• Lynda Mainwaring, Ph.D., C. Psych.
• Doug Richards, MD, Dip. Sport Med.

and their colleagues at the Toronto Rehabilitation Institute (Toronto Rehab)

• Paul Comper, Ph.D., C. Psych.
• Robin Green, Ph.D., C. Psych.

Other co-investigators include:

• Mark Antoniazzi, M.A. and Sean Bisschop, M.A., psychometrists at Toronto Rehab
• Charles Tator, M.D., Ph.D., F.R.C.S.(C), professor and chair of neurosurgery at U of T
• David Mikulis, M.D., F.R.C.P.(C), head of neuroradiology research in the Department of Medical Imaging, U of T
• Vicki Kristman, M.Sc. U of T doctoral candidate in epidemiology

These individuals provide expertise in the medical management of concussion, neuropsychological diagnosis, neuropsychological testing (includes testing of cognition and emotion), experimental design, and statistical analysis. Materials for pilot testing have been provided by the Neurology Service of the Toronto Rehabilitation Institute. The Faculty of Physical Education and Health at the University of Toronto has provided administrative, coaching and infrastructure support. The research team is currently seeking funding for this long-term project from several sources.

Implementation

The multidisciplinary research group has just completed the first year of the study, in which the research design was developed and the initial data collected. Baseline data on varsity athletes deemed at-risk for concussion has begun. Athletes deemed at risk for concussion (i.e. football, rugby, ice-hockey, basketball, lacrosse, volleyball, field hockey and soccer) will be given a battery of neurological and psychological tests to establish a baseline measure of cognitive (i.e., co-ordination, speed, concentration and memory) and emotional functioning. If an athlete experiences a concussion he or she will be re-tested immediately and then at regular intervals until recovery is complete (defined as a return to normal medical and cognitive status, or return to ‘baseline’ functioning). Three groups of volunteer athletes will be studied:

1. concussed athletes (determined onsite by trainers, team physicians using the U of T Sideline Concussion Checklist)
2. knee injured athletes (as an injury control group)
3. a non-injured varsity control.

Outcome

The prospective study will have theoretical and widespread practical importance for scientists, practitioners and policy-makers who seek to understand and intervene in the concussion recovery process. Results will reveal incidence and prevalence rates of concussion in varsity athletes at risk for concussion, and provide guidelines for identifying concussion in the sport context. Often determination of concussion relies on athlete self-report that is coloured by eagerness to return to play, and the promotion of a culture of risk, that may influence the athlete to overlook or conceal symptoms. Also, return to play guidelines, based on clinical neuropsychological empirical evidence, will be developed. Such results address secondary prevention whereas primary prevention strategies for concussions in sport may be identified by the determination of internal risk factors. More generally, findings from the study will help to discern a rate of cognitive and emotional recovery from MTBI for a healthy, motivated population that can then be used as a model of expected uncomplicated recovery for the general population. Consequently, the conclusions and recommendations gleaned from this research will benefit a much wider population than high performance athletes.

Preventing Head Injuries <top>

1. Avoid Risk Factors
   • High risk sports for concussion = collision / contact sports, motor sports, soccer, gymnastics
   • Unsafe venues – hard playing surfaces, diving in shallow water, et cetera
2. Wear Proper Equipment
   • Helmets are essential!
   • They must fit properly – the sort of loose-fit demonstrated recently by Don Brashear makes a helmet next to useless.
   • "Single impact" helmets, such as those used for cycling and motor sports, are most effective, but not practical in sports like football and ice hockey where many impacts to the head occur. These single impact helmets must be disposed of after one knock on the helmet.
   • New, better helmets are now available for multi-impact sports like ice hockey, and they are improving rapidly. The cost is worth it: "If you have a $40 brain, buy a $40 helmet."
   • Helmets should be worn for many sports: football, ice hockey, lacrosse, cycling, skiing, in-line skating, skate-boarding, snow-boarding, and all motor sports to name the most common.
   • Some evidence supports the notion that mouthguards reduce the incidence of concussion when athletes sustain a blow to the jaw (an "uppercut"). For this reason, in addition to the protection they offer the teeth and face, mouthguards are important in sports like rugby, football, ice hockey, basketball, lacrosse, and so on.
3. Play Safely
   Sports have developed some rules over time specifically to reduce the incidence of head and neck injuries. Athletes must play fairly and safely, obeying these rules. Officials must enforce them. Examples of such rules include:
   • No spearing in football – contact must not be initiated with the helmet.
   • No checking from behind and no high-sticking in ice hockey.

First Response to Head Injury

First responders (those providing first aid) to a victim of head / neck injury must:

• Follow the standard first aid protocols (Airway, Breathing, Circulation, …); but
• Stabilize the head and neck first, before checking the airway, and maintain this stability throughout first aid (use hands, knees, sandbags, cushions, etc.) – don’t let the head or neck move!
• Use a modified jaw thrust to open the airway – do not tip the head back!
• Activate the EMS if the victim is unconscious or has significant neck pain.

If the injured person is conscious and stable (breathing easily, steady pulse, not bleeding badly, no neck pain), they should be taken for immediate but non-emergent (no ambulance necessary) medical assessment.

One aspect of the U of T / TRI Concussion Program is the development of a better sideline concussion assessment tool for advanced first responders (physicians and sport therapists). This should not be attempted by most first aiders.

Incidence of Head Injury in Sports

Attempting to estimate the incidence of concussion in sport is difficult for many reasons, the largest of which is historical under-recognition and under-reporting of mild injuries. The injury rates vary tremendously with the choice of activity, which is far and away the number one risk factor for concussion. Based on the most sensitive tests for injury, and recent experience with Varsity sports, some ballpark guesses include:

• Approximately 20 mild concussions per 1,000 athlete exposures (practices or games) the highest risk sports like football, rugby and full-contact ice hockey.
• Approximately 5 mild concussions per 1,000 athlete exposures in moderate risk sports like basketball.
• Approximately 1 mild concussion per 1,000 athlete exposures in lower risk sports like volleyball.

The prospective study will have theoretical and widespread practical importance for scientists, practitioners and policy-makers who seek to understand and intervene in the concussion recovery process. Results will reveal incidence and prevalence rates of concussion in varsity athletes at risk for concussion, and provide guidelines for identifying concussion in the sport context. Often determination of concussion relies on athlete self-report that is coloured by eagerness to return to play, and the promotion of a culture of risk, that may influence the athlete to overlook or conceal symptoms. Also, return to play guidelines, based on clinical neuropsychological empirical evidence, will be developed. Such results address secondary prevention whereas primary prevention strategies for concussions in sport may be identified by the determination of internal risk factors. More generally, findings from the study will help to discern a rate of cognitive and emotional recovery from MTBI for a healthy, motivated population that can then be used as a model of expected uncomplicated recovery for the general population. Consequently, the conclusions and recommendations gleaned from this research will benefit a much wider population than high performance athletes.

References

American Academy of Neurology. Quality Standards Committee (1997), Practice parameter: the management of concussion in sports. Neurobiology (Bp). 48, 1-5.

Barth, JT, Alves, WM, Ryan, TV, et al. (1989). Mild head injury in sports: neuropsychological seqeuelae and recovery of functions. In Levin, HS, Eisenberg, HM, Bento Al (Eds). Mild Head Injury. New York, NY: Oxford University Press, 257-275.

Collins, M., Grindel, S., Lovell, M., Dede, D., Moser, D., Phalin, B., Nogle, S., Wasik, M., Cordry, D., Daugherty, M., Sears, S., Nicolette, G., Indelicato, P., an McKeag, D, (1999). Relationship between concussion and neuropsychological performance in college football players. JAMA, 282 (10), 964-970.

Collins, M., Lovell, M., and McKeag, D., (1999). Current issues in managing sports-related concussion. JAMA, 282 (24), 2283-2285.

Echemendia, R. Neuropsychological Assessment of the College Athlete: The Penn State Concussion Program. Personal Communication. 1999.

Esselman, PC., Uomoto, JM. (1995). Classification of the spectrum of mild traumatic brain injury. Brain Injury. 9,417-424.

Kelly, James P. (1999). Traumatic brain injury and concussion in sports. JAMA, 282 (10), 989-991.

Kelly, JP., Nichols JS., Filley, CM., Lillehei, KO., Rubinstein, D., Kleinschmidt-Demasters, J. (1991). Concussion in sports: guidelines for the prevention of catastrophicoutcome. JAMA, 266 (20), 2867-2869.

"There will always be another game, but you only have one brain. When in doubt, stay out!