By Kris Lines, Teaching Fellow at Aston University
A recent study, published earlier this year in Acta Neuropathol (a peer-reviewed medical journal), suggests that there may be a causal link between professional association football (soccer) and the development of chronic traumatic encephalopathy (CTE). The study was conducted by a team of researchers from University College London (UCL), Cardiff University and Cefn Coed Hospital and was funded by the National Institute for Health Research, and the Drake Foundation.
Fourteen retired male footballers who had developed dementia in later life, were followed by researchers over a 30-year period (from 1980-2010). Each footballer had previously been regarded as a skilled header of the ball, and had played regularly since their childhood for an average of 26 years. Half of the men played at either centre-half or as centre-forwards (positions typically associated with repeated heading of the ball). Furthermore, six of the footballers had reported at least one concussion, five of them with a loss of consciousness.
The men were all clinically assessed and monitored regularly until their death. In 2015-16, the researchers obtained demographic and clinical data from a systematic review of medical records and from interviews with their close relatives. This provided researchers with the footballers’ playing history (including position), other sporting experience (two of the men had been amateur boxers), military service, number and severity of any concussions, and dementia history. Consent was further granted from six of the families for a post-mortem brain examination.
Of the six men examined, the researchers found that all six had Alzheimer’s disease, deposits of TDP-43 (found in motor neurone disease, MND) and some features of CTE (although only four fit the CTE diagnosis criteria). This represented a significant increase in the 12 percent average background rate of CTE found in a previous survey of 268 brains.
The study is not unique in highlighting the potential risks of repeated head injuries in football (soccer). Indeed, whether the players used the heavier 450g leather footballs (as the patients in this study), or the lighter synthetic balls used by modern footballers, there is a growing body of evidence that repetitive head impacts and sub-concussive events may lead to CTE. This study is important as it is the first time that CTE has been diagnosed in a group of retired footballers.
It is however important to state, as the researchers themselves acknowledge, that this study does not definitively prove any casual links between CTE and soccer. Instead, while the small-scale descriptive nature of the study supports the urgent need for future long-term surveillance efforts to identify at risk groups of footballers, there is also a pressing demand for large-scale case-control studies to compare footballers who do not have cognitive problems with those who do. In particular, the study lacks important genetic and lifestyle information for the people involved, which may need to be accounted for and balanced against the well-established benefits of being physically active.
“We do not yet know exactly what causes CTE in footballers or how significant the risk is,” says co-lead author Professor Huw Morris (UCL Institute of Neurology), Professor of Clinical Neuroscience and honorary consultant neurologist at the Royal Free Hospital and National Hospital for Neurology and Neurosurgery. “Major head injuries in football are more commonly caused by player collisions rather than heading the ball. The average footballer heads the ball thousands of times throughout their career, but this seldom causes noticeable neurological symptoms. More research is now urgently needed to determine the risks associated with playing football so that any necessary protective measures can be put in place to minimise potential long term damage.”
Michelle Crorie, head of accident and health at international law firm Clyde & Co concurs:
“More scientific study is needed, but we appear to be moving inexorably towards a situation in which large numbers of former players — and perhaps current players — may seek compensation for the toll the game has taken on them. Claims pursued in relation to historical incidents bring with them the search for old insurance policies and, where there is a cumulative effect across a long period of time, issues of allocation across a range of years.”
The 2014 class action lawsuit in the District Court in California against FIFA, US Soccer and the American Youth Soccer organization may have prohibited players under the age of 10 from heading the ball, and will reduce headers in practice for those ages 11 to 13. However, these regulations are not binding on other soccer associations or federations not under the control of US Soccer. This has led to the situation that country of origin and the location of the game may have important consequences for the future health of a player. We may not yet know how many low-impact blows to the head might predispose a player to future dementia. However, what we do know from other contact sports is that a wait-and-see approach will lead to class action lawsuits further down the line.
The Research study can be found at: http://link.springer.com/article/10.1007/s00401-017-1680-3
