Contact sport athletes are returning to play too soon after concussion, study finds
New research from Monash University into brain changes post-concussion indicates that the brain remains injured and potentially vulnerable after more than two weeks – raising concerns that new AFL concussion guidelines may be still allowing athletes to return to play before the brain has fully recovered.
In a paper published in the journal, Cerebral Cortex, Monash researchers conducted MRI scans on concussed athletes from amateur Australian Football clubs in Melbourne at both 48-hours and 2 weeks after their concussion, and compared them to non-concussed athletes.
The study, led by Associate Professors David Wright, Richelle Mychasiuk and Sandy Shultz, from the Monash University Department of Neuroscience, found – even after 2 weeks post-concussion when the athletes were cleared to return to play (and importantly, when the athletes reported no concussion symptoms) - clear signs of changes indicative of white matter injury in the brains, as detected by MRI.
According to Associate Professor Wright, the findings raise concerns over new guidelines announced by the AFL earlier this year, which specifies a minimum 12-day return to play protocol following a concussion. “While this is a step in the right direction, this data indicates that players can still be returning to play too early, with injury to their brain potentially exacerbated by further head-knocks,” he said.
The paper also provided initial evidence that the brains of men and women AFLers may be affected differently by a concussion. Although both men and women had differences that persisted for 2 weeks after concussion, the women appeared to have less injury than the men. According to Associate Professor Wright, “further research is required to confirm these preliminary results – however, we are in a unique position internationally to do these studies given that similar rules are in place for both men’s and women’s AFL codes,” he said. This is not the case in other popular international collision sports such as American football and ice hockey.
Although it is currently not possible for every individual with a concussion to have an MRI scan, Associate Professor Shultz says that this study confirms previous research from their group published earlier this year, which revealed blood biomarkers for brain injury present in players more than 2 weeks post-concussion.
Australian football is the most popular collision sport in Australia – with an average of 6-7 concussions occurring every 1000 match hours across amateur and professional leagues. Despite this high incidence of mild traumatic brain injury, there has been little study of the long-term neurological damage associated with this sport and how to prevent it.
Associate Professor Shultz said there is significant global interest in a blood test that could monitor an athlete’s recovery from concussion. “Currently we are reliant on athletes telling us when they are symptom free or through the use of cognitive tests, which have problems with reliability and validity,” he said.
“A blood or saliva test, which we have now shown to be supported by MRI of the brain itself, would allow doctors to monitor an athlete’s brain recovery and help to ensure they only return to play when they are fit to do so.”
He added that, as concussion is a major problem for sports around the world, such a test would have a global market. In the US a large number of former National Football League (NFL) players have been diagnosed with Chronic Traumatic Encephalopathy (CTE), a progressive neurodegenerative disease caused by brain trauma leading to premature deaths often associated with dementia or violent behaviour. The NFL recently settled a class action mounted by 4500 former players in 2012 for $US765 million (AUD$1 billion) and there have been similar threats of class actions from former NRL and AFL players.
- David K Wright, Georgia F Symons, William T O’Brien, Stuart J McDonald, Akram Zamani, Brendan Major, Zhibin Chen, Daniel Costello, Rhys D Brady, Mujun Sun, Meng Law, Terence J O’Brien, Richelle Mychasiuk, Sandy R Shultz, Diffusion Imaging Reveals Sex Differences in the White Matter Following Sports-Related Concussion, Cerebral Cortex, 2021; bhab095, https://doi.org/10.1093/cercor/bhab095
- Monash Trauma Group: https://www.monash.edu/medicine/ccs/neuroscience/research/monash-trauma-group
- Professor Meng Law explains Chronic Traumatic Encephalopathy (CTE): video