Why is head trauma making the headlines?
01 June 2018
Head trauma has become a hot topic in recent years, particularly in the sports world, as a growing body of research suggests even minor concussion and one-off impacts to the head can cause serious and long term health issues. Georgina Bisby examines the latest research and considers the wider implications for head protection
In July 2017 a study published in the medical journal, JAMA, found evidence of Chronic Traumatic Encephalopathy, currently known as CTE, in 99% of deceased National Football League (NFL) players' brains that had been donated to scientific research. This was sobering, but not altogether shocking, as by this point it was well documented that frequent knocks to the head, such as the regular concussions experienced by NFL players, could cause neurodegeneration. It was also suspected that returning to play too soon after a head trauma could delay recovery with the brain likely to be vulnerable to further changes immediately after an injury.
What was more surprising however were the findings of the largest study of its kind, published in JAMA Neurology in May 2018, that showed that just one mild traumatic brain injury could have long term health effects and double the risk of dementia later in life.
Researchers from UCSF Weill Institute for Neurosciences and the San Francisco Veterans Affairs Health Care System looked at more than one-third of a million veterans to evaluate the risk of complications in those who suffered from concussions.
After adjusting for age, sex, race, education and other health conditions, they found that those who had experienced concussion without loss of consciousness led to 2.36 times the risk for dementia. These risks were slightly elevated for those in the loss-of-consciousness bracket (2.51) and were nearly four times higher (3.77) for those with the more serious moderate-to-severe traumatic brain injury.
The study identified participants from two databases: one listing all-era veterans whose traumatic brain injuries included concussion or mild traumatic brain injury which could have occurred during civilian or military life; and the second from veterans serving in Iraq and Afghanistan, for whom most of these injuries had occurred in combat zones, such as from shockwaves in blasts.
"The findings in both groups were similar, indicating that concussions occurring in combat areas were as likely to be linked to dementia as those concussions affecting the general population," said first author Deborah Barnes, PhD, MPH, professor in the UCSF departments of psychiatry, and epidemiology and biostatistics.
In total, 357,558 participants, whose average age was 49, were tracked. Half had been diagnosed with traumatic brain injury, of which 54 per cent had had concussion. The study followed participants for an average of 4.2 years; 91 per cent were male and 72 percent were white.
Among Iran and Afghanistan veterans, concussion was defined as mild traumatic brain injury resulting in alteration of consciousness and amnesia for one day or less, based on a comprehensive medical evaluation. In the other veterans, concussion was defined using a wide list of diagnostic codes in the electronic health record.
Discussing the findings, senior author and principal investigator Kristine Yaffe, MD, professor in the UCSF departments of neurology, psychiatry, and epidemiology and biostatistics, said: ”There are several mechanisms that may explain the association between traumatic brain injury and dementia. There's something about trauma that may hasten the development of neurodegenerative conditions. One theory is that brain injury induces or accelerates the accumulation of abnormal proteins that lead to neuronal death associated with conditions like Alzheimer's disease.
"It's also possible that trauma leaves the brain more vulnerable to other injuries or aging processes," said Yaffe, "but we need more work in this area.”
Kristine Yaffe advises: For those who experience a concussion, get medical attention, allow time to heal and try to avoid repeat concussions. Although our study did not directly examine this issue, there is growing evidence that repeated concussions appear to have a cumulative effect."
The study's results are the latest in a growing volume of research that links concussion and other traumatic brain injuries to various psychiatric and neurodegenerative disorders. In April 2018, UCSF researchers also reported a link between concussion and Parkinson's disease, this time finding veterans who had experienced concussion faced a 56 per cent increased risk for Parkinson’s.
Making an impact
Meanwhile research into the association between sports-related head traumas and brain injury has been ongoing. In 2016 the International Concussion and Head Injury Research Foundation (ICHIRF), begun a three year project looking at the long-term effects of concussion in men and women who have competed in impact sports. Part of a multi-national collaboration between concussion research centres in Australia, Switzerland and the USA, the ICHIRF is seeking to establish whether retired sportsmen and sportswomen have an increased incidence of, or suffer an earlier onset of euro-degenerative disorders such as Parkinson’s Disease, Alzheimer’s Disease and CTE.
For the first 12 months, ICHIRF concentrated its research on retired jockeys, both amateur and professional, but the project has now been expanded to include athletes from a wide variety of other impact sports.
Elsewhere, in the US, after initial reluctance to address the issue, the NFL is now funding research into head trauma and in 2016 launched Play Smart, Stay Safe, which it describes as a commitment to “drive progress in the prevention, diagnosis and treatment of head injuries, enhance medical protocols and further improve the way the game is taught and played.”
There are already some interesting developments in terms of head protection coming out of the Play Smart, Stay Safe initiative. The project's biomechanical engineers have suggested taking lessons from the automobile industry where modern tools and rich data analysis have been used to improve safety could lead to improvements in head protection. Specifically they believe the collection of data accurately representing on-field impacts will enable engineers to improve helmet performance. Once the problem can be measured, the engineering community can work on creating a better helmet. The NFL says its goal is to provide the resources and information to stimulate the marketplace to design solutions.
Tackling risks in rugby
The rugby world has also been compelled to take action, bringing in a new law for head injury assessments in August 2017 but the sport is under increasing pressure to go further. One UK brain expert suggesting that the game should limit contact time during training sessions. Consultant neuropathologist Dr Willie Stewart told the BBC that rates of concussion in the professional game are still "unacceptably high" and suggests limiting or banning contact training sessions during the season would be a significant step towards reducing the risk of brain injury for players.
Others would like to see more done to prevent head trauma at a youth sport level. In March 2016, scientists and doctors from the Sport Collision Injury Collective a multidisciplinary collective of academics who say they are committed to reducing injuries sustained in youth sport called for tackling in youth rugby to be banned. So far their calls have been rejected; with health experts citing lack of exercise and obesity as greater threats to children’s health but this has not quietened the campaigners.
In an opinion piece published in the British Medical Journal (BMJ) in September 2017, Allyson Pollock and Graham Kirkwood from the Institute of Health at Newcastle University and part of the collective urged once again that harmful contact should be prohibited during school rugby games.They pointed to the fact that most injuries in youth rugby occur due to the collision elements of the game and urged ministers to “put the interests of the child before those of corporate professional rugby unions”. The academics also suggested that “teacher training in the skills of rugby are lacking, as is concussion awareness training.” Professor Pollock, went on to urge that under United Nations conventions, governments have a “duty to protect children from risks of injury”. World Rugby rejected the claims as “extreme and alarmist” a sentiment which was echoed by The Rugby Football Union.
As these debates and recent research findings show, head trauma in sport is an emotive and complex area and there are still a great many unanswered questions about its prevalence and long-term effects. What is clear is that in light of latest research the traditional attitude in some sports that playing through concussion is just 'part of the game' is no longer acceptable which is likely to have a knock on effect in the workplace. Greater understanding and awareness of the consequences of head trauma may well inspire a universally more cautious approach to dealing with impacts to the head and employers may look for areas where there is room for improvement. For example, while most employers understand that where there is a risk of impact to the head from moving objects, an industrial safety helmet in accordance with BS EN 397:2012 is required, fewer employers consider bump caps for scenarios where there is a risk of impact between the head and stationary objects such as low ceilings, work stations or overhead piping. This is perhaps because sporting culture has traditionally portrayed knocks to the head as a benign and every day occurrence, but with an increasing body of evidence suggesting otherwise, it seems this attitude is ripe for review both on and off the sports field.