SciLine, a free service hosted by the American Association for the Advancement of Science, aims to strengthen the quality of news coverage by giving reporters easy access to experts and the latest, research-based scientific evidence. They have compiled a helpful list of sources for sports and health reporters who find themselves covering the issue of concussions.
Concussions are a common but enigmatic brain injury. They can happen to anyone, affect individuals vastly differently, and leave no visible mark on the brain. The symptoms of a concussion can be easily mistaken for other conditions and, in some cases, are difficult or even impossible to detect. Concussions have been in the medical lexicon for thousands of years, but their mechanisms of action and long-term health effects are still poorly understood. There is currently no evidence-based treatment for concussions other than rest and their medical management is largely guided by individual expert opinion, which varies considerably. But an emerging body of systematic research, bolstered by increasingly vocal testimony from athletes and other groups at high risk for concussions, is starting to paint a clearer picture of how these injuries work and their potentially serious, lasting consequences.
Here’s some of the scholarship on concussions:
- A 2014 paper, The First Concussion Crisis: Head Injury and Evidence in Early American Football, published in the American Journal of Public Health, provides an historical review of scientific and societal milestones related to concussions and describes the evolution of the sport and medical communities’ approach to this injury over the last century.
- The Centers for Disease Control and Prevention (CDC) provides comprehensive statistics and trends in TBI incidence in its 2017 report, Traumatic Brain Injury-Related Emergency Department Visits, Hospitalizations, and Deaths – United States 2007 and 2013. One of the report’s key findings is that more attention should be paid to older-adult falls as a major cause of TBI in the U.S.
- The largest body of concussion research relates to sports- and recreation-related TBI. Several studies of high-school and collegiate athletes point to the elevated risks associated with repeat concussive episodes. A 2015 paper, Epidemiology of sports-related concussion in seven US high school and collegiate sports, published in Injury Epidemiology provides an overview of concussion incidence across different types of sports. A 2010 study in the Journal of the American Medical Association (JAMA), Cumulative Effects Associated with Recurrent Concussions in Collegiate Football Players, describes the impact of previous concussion history on risk for future episodes.
- In 2017, a major study of the brains of deceased American football players published in the JAMA found that 110 out of 111 brains examined had clear signs of significant CTE. This study is one of the largest and most significant direct studies of CTE in the human brain, but importantly, its samples were “self-selected” – including only specimens from athletes who participated in high-contact sports during their adult lives. Another 2017 post-mortem study of deceased soccer players who had exhibited signs of dementia before death found similar physical evidence of extreme CTE.
- Other recent studies are beginning to shed light on the cumulative contributions of repeat sub-concussive episodes to CTE-related cognitive decline (NeuroImage: Clinical, 2017), as well as how CTE propagates and the specific proteins involved in its destruction of healthy brain cells (PLOS One, 2017).
- Several studies, including a 2017 epidemiological assessment in the Orthopaedic Journal of Sports Medicine and a 2018 study of concussion incidence among young athletes in the Archives of Clinical Neuropsychology show that, contrary to historical assumptions, in many settings, female athletes are at higher concussion risk than their male counterparts, particularly female soccer players. Other studies on neck strength (Journal of Athletic Training, 2017), symptom reporting (Journal of Adolescence, 2017), and hormonal factors (Obstetrics and Gynecology, 2017) are beginning to explore the potential drivers for these gender differences, but more research is needed.
- A 2016 study, Sports- and Recreation-Related Concussions in U.S. Youth, in the journal Pediatrics, offers one of the most detailed estimates of pediatric sports- and recreation-related concussions in the United States. It finds that American children experience between 1.1 – 1.9 million sports- and recreation-related concussions annually. Other studies in Health Education and Behavior (2017) and Child: Care, Health, and Development (2017) describe the risks and social challenges related to underreporting of concussions among young children and youth athletes. These and other studies emphasize the role of educating parents about ways to reduce concussion risks.
- Two 2012 papers in Current Translational Geriatrics and Experimental Gerontology Reports—Mild Traumatic Brain Injury among the Geriatric Population and Traumatic Brain Injury in the Elderly: Is it as Bad as we Think?—describe the landscape of risks related to mild traumatic brain injury for elderly adults.
- A 2018 report, Protecting Warfighters from Blast Injury, published by the Center for a New American Security (an independent, bipartisan, nonprofit think tank) summarizes several studies by the Department of Defense about the incidence and impact of explosive-blast exposures on the brain health of servicemembers. A 2013 report by the CDC to Congress, Understanding the Public Health Problem among Current and Former Military Personnel, found that from 2000 to 2011, 4.2 percent of servicemembers across all components of the U.S. military were diagnosed with TBI, mostly in the “mild” category. The report also outlines the challenges associated with data gathering on TBI among active duty servicemembers and estimates the economic cost of TBI in the military.
- A 2018 consortium study of patients in the Veteran’s Health Administration published in Neurology suggests that history of mTBI (even a single episode) may be associated with a 56 percent increased risk for developing Parkinson’s disease. The large sample size is a strength of the study, but it may not fully account for other Parkinson’s disease risk factors in this population, such as alcohol use and post-traumatic stress disorder. Moreover, overall risk for developing this disease remains very low, even among TBI patients. A 2015 study in Neuropathologica Acta suggests links between repetitive mTBI-induced CTE and elevated risk of Alzehimer’s disease, but more research is needed.
- A 2015 clinical-literature review in the journal Brain Injury, summarizes the evidence base for existing concussion management strategies and concludes that while promising work is being done, there is a lack of systematic research on standardized treatment protocols for patients following a concussion. A 2016 study of mice with repeat TBI in the American Journal of Pathology offered some of the first direct evidence (albeit in animal models) to support rest as a critical window for restoration of damaged neural networks following brain injury. A 2017 evaluation in the British Journal of Sports Medicine looks specifically at rest as a treatment strategy and finds that while there is evidence to support a brief period of cognitive and physical rest for most concussed patients, more research is needed to define rest-duration, monitoring, and activity-reintroduction protocols.
- Real-world efficacy of a new TBI blood test approved in 2018 by the FDA remains to be observed and emerging research on the possibility of in-vivo diagnosis of CTE and medications to prevent or reverse CTE symptoms is nascent.
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