Concussion in Australian collision sports 'under-researched'

Ms Georgia Fuller Symons, first author

on the paper, demonstrating the frame

for ocular motor function tests, one of 

the indicators of brain trauma

by Anne Crawford

Concussion sustained during collision sports including AFL and rugby, and its effects on players, is a growing issue in Australia but research into the subject is limited and lacks consensus, a paper by Monash University Department of Neuroscience researchers has found.

First author PhD student Georgia Symons said the review, which appeared recently in the Journal of Neurotrauma, found that most literature on the topic predominantly looked at North American contact sports such as ice hockey and NFL, and also European sport.


Australian researchers have contributed to the field but several knowledge gaps and limitations currently exist, the paper found.

Department of Neuroscience researchers were invited to write the review as part of the Journal of Neurotrauma’s 2020 International Neurotrauma Symposium special issue highlighting Australian neurotrauma research.

“The review really highlighted the lack of research about the neurological consequences of collision sports in Australia including Australian rules football and rugby codes, but also that there is little consensus across the literature – the studies had different time courses they looked at, different analysis techniques and imaging paradigms, among others,” Ms Symons said.

“Generally we also found that findings in Australian sport were similar to Americans sports, despite those events being helmeted. It's important to study Australian sports since they are different, but also can induce similar neurological changes.

“Australian scientists really need to come together to refocus on Australian collision sports and perform well-controlled studies, ideally with common data elements to draw consensus between studies,” she said.

Increasing concern exists about the long-term consequences of repeated mild brain traumas in Australian collision sports. The late AFL footballer Graham “"Polly" Farmer was found recently following an autopsy to have suffered chronic traumatic encephalitis (CTE) – the first case of an AFL footballer to have been diagnosed with the disease. The champion footballer was diagnosed at 64 with Alzheimer's disease as well as depressive symptoms, loss of attention and concentration, short-term memory loss and headaches. CTE has also been identified in the brains of two former rugby league players.

Clinicians say the only known risk factor in developing the disease is repetitive head injury.

“We know that when you’re engaging in collision sports, you’re vulnerable to sustaining impacts over your playing career and potentially long-term consequences of these,” Ms Symons said. “In the past the literature has mainly been looking at a history of concussion but more research is suggesting the build-up of repetitive impacts that maybe don’t lead to concussion – sub-concussive impacts – are also having an effect.”

These long-term consequences of mild brain trauma include: cognitive dysfunction such as problems with memory and attention; mental health conditions such as anxiety and depression; and increased risk of severe neurodegenerative conditions such as Alzheimer’s and Parkinson’s disease.

The paper reviewed previous studies investigating neurocognition, ocular motor function, neuroimaging and fluid biomarkers as indicators of mild brain trauma, as well as neuropathological outcomes in these athletes.

“It’s really necessary to have these biomarkers to identify high-risk people and prevent them from sustaining long-term damage,” Ms Symons said. “Ideally, biomarkers would be used for diagnosis and prognosis and seeing when players could return to play after concussion and whether they could potentially have more serious long-term effects later such as Alzheimer’s and CTE,” she said.

“If someone was showing early signs of neurological changes biomarkers maybe help to intervene before they develop the long-term consequences.”

The review concluded that while Australia has an active history of investigating the neurological impact of collision sport participation, further well-controlled research was needed to better understand these consequences in Australian athletes, and how they can be mitigated.

Knowledge gaps included important questions related to sex differences, the identification and implementation of blood and imaging biomarkers, the need for consistent study designs and common data elements, as well as more multimodal studies.

“Multimodal studies are really important because the conditions are so heterogeneous between people that it’s unlikely that one biomarker alone would be useful to encompass all the things going on with the condition,” Ms Symons said.

Future research into collision sports such as AFL would ideally be generalisable to a range of other mild brain injuries sustained in other athletes, people in motor vehicle accidents or those injured in war zones. However, additional large scale studies are still required.

Supervised by senior author on the review, Associate Professor Sandy Shultz, Ms Symons is part of the Monash Trauma Group laboratory. The team is actively researching the area, including research testing men and women amateur Australian Rules footballers using multimodal biomarkers including blood, saliva, MRI and ocular motor tests.

Said Associate Professor Shultz, “Georgia’s exciting initial findings suggest that these complementary objective methods might be applied in the not so distant future to improve the clinical management of athletes with mild brain traumas.”

The study will appear as a poster at the International Neurotrauma Symposium 2020 in Melbourne, which has been postponed due to COVID-19 and will now be held in 2021.

J Neurotrauma. 2020 Feb 14. doi: 10.1089/neu.2019.6884. The neurological consequences of engaging in Australian collision sports. Symons GF, Clough M, Fielding J, O'Brien WT, Shepherd CE, Wright DK, Shultz SR.