- There is currently insufficient data to accurately estimate the incidence of sports-related concussions in youth and in subpopulations of youth. Existing surveillance systems, including the National Collegiate Athletic Association Injury Surveillance System and the High School RIO™ surveillance system, provide data for collegiate and high school–level athletes in select sports. There are very limited data on the incidence of sports-related concussions among pre-high-school-age youth and among those playing in youth clubs and recreational sports. There is also inadequate collection of data on potential concussion risk factors and modifiers. Understanding of the epidemiology of sports-related concussions is further hindered by variations in terminology and the data elements employed in relevant research. Federal interagency initiatives to identify common data elements for traumatic brain injury research, including research on concussions, and to develop the Federal Interagency Traumatic Brain Injury Research (FITBIR) informatics system may help to advance such research through the use of common definitions and standards. Incomplete data limits understanding of not only the incidence of sports-related concussions in youth overall and in specific sports but also of where there might be disparities and a need for targeted interventions. More complete epidemiological data would better enable researchers to assess the effectiveness
of legislation and other interventions in reducing the incidence of sports-related concussions in youth.
Recommendation 1. The Centers for Disease Control and Prevention, taking account of existing surveillance systems and relevant federal data collection efforts, should establish and oversee a national surveillance system to accurately determine the incidence of sports-related concussions, including those in youth ages 5 to 21. The surveillance data collected should include, but not be limited to, demographic information (e.g., age, sex, race and ethnicity), preexisting conditions (e.g., attention deficit hyperactivity disorder, learning disabilities), concussion history (number and dates of prior concussions), the use of protective equipment and impact monitoring devices, and the qualifications of personnel making the concussion diagnosis. Data on the cause, nature, and extent of the concussive injury also should be collected, including
- Sport or activity
- Level of competition (e.g., recreational or competitive level)
- Event type (e.g., practice or competition)
- Impact location (e.g., head or body) and nature (e.g., contact with playing surface, another player, equipment)
- Signs and symptoms consistent with a concussion
- Research involving animals and individuals with more severe head injuries has provided a limited understanding of neurophysiological changes that take place following a concussion and of potential biomarkers of concussion. As the diagnosis of concussion is currently based primarily on symptoms, there is a major need for objective diagnostic markers of concussion as well as for objective markers of recovery. Neuropsychological tests used alone will not be appropriate for the identification of concussions or for diagnosis until better studies are conducted that can provide more accurate and valid information about the relation of test scores to cognitive impairment after a concussion.
- Existing guidelines for the treatment and management of concussions and their short- and long-term sequelae in youth are based primarily on clinical experience rather than on scientific evidence. Additional prospective studies that include children and adolescents are needed in order to be able to define typical and atypical recovery from sports-related concussion. Randomized controlled trials or
other appropriately designed studies on the management of concussion and on post-concussion syndrome in youth are needed in order to develop empirically based clinical guidelines, including studies to determine the efficacy of physical and cognitive rest following concussion, the optimal period of rest, and the best protocol for returning individuals to full physical activity as well as to inform the development of evidence-based protocols and appropriate accommodations for students returning to school. Prospective studies to delineate individual differences in concussion symptomatology and course as well as the predictors of recovery and persistence in children and adolescents with sports-related concussions are also needed in order to identify individuals who are likely to have persistent symptoms and therefore to be in need of intervention.
Recommendation 2. The National Institutes of Health and the Department of Defense should support research to (1) establish objective, sensitive, and specific metrics and markers of concussion diagnosis, prognosis, and recovery in youth and (2) inform the creation of age-specific, evidence-based guidelines for the management of short- and long-term sequelae of concussion in youth.
- Epidemiological studies of the neurocognitive effects of repetitive head impacts (i.e., head impacts that do not result in symptoms of concussion) and multiple concussions in high school and collegiate athletes have had mixed results, and many are limited by small sample sizes and methodological weaknesses. There are limited data from imaging research indicating that repetitive head impacts result in changes to the integrity of brain white matter. Research involving retired professional football players provides preliminary evidence of a positive association between the number of concussions an athlete has sustained and the risk of depression; however, data on the relationship between the number of concussions and the risk of suicide are not available. Whether repetitive head impacts and multiple concussions sustained in youth increases the risk for long-term neurodegenerative diseases, such as chronic traumatic encephalopathy (CTE) and Alzheimer’s disease, remains unclear. Additional research is needed to determine whether CTE represents a distinct disease entity or is part of a spectrum of disease manifestations that share a common finding of tau pathology, as well as to identify biomarkers for the in vivo diagnosis of CTE
and the early detection of neurodegeneration in athletes that may be related to repetitive head impacts and multiple concussions.
Recommendation 3. The National Institutes of Health and the Department of Defense should conduct controlled, longitudinal, large-scale studies to assess the short- and long-term cognitive, emotional, behavioral, neurobiological, and neuropathological consequences of concussions and repetitive head impacts over the life span. Assessments should also include an examination of the effects of concussions and repetitive head impacts on quality of life and activities of daily living. It is critical that such studies identify predictors and modifiers of outcomes, including the influence of socioeconomic status, race and ethnicity, sex, and comorbidities. To aid this research, the National Institutes of Health should maintain a national brain tissue and biological sample repository to collect, archive, and distribute material for research on concussions.
- Rules are the foundation for safe play in sports and have the potential to discourage player behaviors that may increase the risk of injury and to advance a culture in which youth athletes are not pressured to play through their injuries or return to activity before they have fully recovered. There is some evidence from studies of youth ice hockey and soccer that the modification and enforcement of rules to promote player safety and fair play policies contribute to a reduction in practices that contribute to sports-related injuries, including concussions. Although this evidence is promising, more rigorous research is needed to measure the effectiveness of rules, regulations, and playing standards across a variety of sports and among youth athletes at different ages for fostering changes in norms and beliefs (e.g., among athletes, coaches, officials, and parents) and reducing the occurrence of concussions and other injuries. Such research also is needed to inform the development of effective standards for return to physical and cognitive (e.g., school, work) activity.
Recommendation 4. The National Collegiate Athletic Association, in conjunction with the National Federation of State High School Associations, national governing bodies for youth sports, and youth sport organizations, should undertake a rigorous scientific evaluation of the effectiveness of age-appropriate techniques, rules, and playing and practice standards in reducing sports-related concussions and sequelae.
The Department of Defense should conduct equivalent research for sports and physical training, including combatives, at military service academies and for military personnel.
- Available studies of head injury biomechanics are based on models that have limited applicability to concussions in youth or to concussions that occur in sports environments. Thus there is currently inadequate data to determine the thresholds associated with sports-related concussive injuries in youth. In addition, it is unclear if or when the threshold of injury for a second concussion might be lower than for an initial injury. Research is needed to identify biomechanical thresholds and risk curves specifically for sports-related concussions in youth to better inform the development of protective equipment, head-impact-monitoring devices, athletic training programs, and sports rules in an effort to reduce sports-related concussions in youth. Given the potential physiological differences in concussion risk between males and females and youth of different ages, this research should explicitly take into account both age and sex.
Recommendation 5. The National Institutes of Health and the Department of Defense should fund research on age- and sex-related biomechanical determinants of injury risk for concussion in youth, including how injury thresholds are modified by the number of and time interval between head impacts and concussions. These data are critical for informing the development of rules of play, effective protective equipment and equipment safety standards, impact-monitoring systems, and athletic and military training programs.
- Acknowledgment of the seriousness of sports-related concussions has initiated a culture change, as evidenced by campaigns to educate athletes, coaches, physicians, and parents of young athletes about concussion recognition and management; by rule changes designed to reduce the risk of head injury; and by the enactment of legislation designed to protect young athletes suspected of having a concussion. Despite such efforts, there are indications that the culture shift is not complete. Athletes profess that the game and the team are more important than their individual health and
that they may play through a concussion to avoid letting down their teammates, coaches, schools, and parents. Given the serious nature of concussions and the potential for additional injury during recovery, it is important to foster a culture of acceptance that encourages the reporting of concussive injury and compliance with appropriate concussion management plans, including restrictions aimed at preventing athletes from returning to play before being fully recovered.
Recommendation 6. The National Collegiate Athletic Association and the National Federation of State High School Associations, in conjunction with the Centers for Disease Control and Prevention, the Health Resources and Services Administration, the National Athletic Trainers’ Association, and the Department of Education, should develop, implement, and evaluate the effectiveness of large-scale efforts to increase knowledge about concussions and change the culture (social norms, attitudes, and behaviors) surrounding concussions among elementary school through college-age youth and their parents, coaches, sports officials, educators, athletic trainers, and health care professionals. These efforts should take into account demographic variations (e.g., socioeconomic status, race and ethnicity, and age) across population groups. The Department of Defense should conduct equivalent research for military personnel and their families.
- Efforts to increase concussion knowledge and to change behavior among young athletes might include the development by the Department of Education, the Centers for Disease Control and Prevention, the National Athletic Trainers Association, or other organizations of evidence-based curricula with which to educate elementary, middle, and high school students about concussions, including sports-related concussions. It will be important to evaluate the effectiveness of concussion education programs on students’ knowledge of concussions and on their attitudes toward and compliance with guidelines for removal from play and return to physical and cognitive activity following concussion. Parallel efforts perhaps involving the National Collegiate Athletic Association (NCAA), the National Federation of State High School Associations, national governing bodies for youth sports, and youth sports organizations might be undertaken for collegiate athletes, coaches, and officials.
- There is a need for school administrators, teachers, guidance counselors, and school nurses or student health services to receive evidence-based education about the potential effects of concussions on cognitive function and behavior and for them to provide appropriate academic and emotional support for students recovering from concussion. The NCAA and the Department of Education could fund research to develop evidence-based curricula and procedures to assist local school districts and other institutions in implementing such education efforts.
- It is important for health care professional credentialing bodies to incorporate evidence-based standards for concussion diagnosis and management into the core curricula for students in medicine, nursing, and other health professions and to provide continuing medical education on concussion diagnosis and management to practicing professionals.