The neurological consequences of engaging in Australian collision sports.

Collision sports are an integral part of Australian culture. The most common collision sports in Australia are Australian rules football, rugby union, and rugby league. Each of these sports often results in participants sustaining mild brain traumas such as concussive and subconcussive injuries. However, the majority of previous studies and reviews pertaining to the neurological implications of sustaining mild brain traumas while engaging in collision sports have focused on those popular in North America and Europe. As part of this 2020 International Neurotrauma Symposium special issue, which highlights Australian neurotrauma research, this paper will therefore review the burden of mild brain traumas in Australian collision sport athletes. Specifically, this review will first provide an overview of the burden of mild brain trauma in Australian collision sports, followed by a summary of the previous studies that have investigated neurocognition, ocular motor function, neuroimaging and fluid biomarkers, as well as neuropathological outcomes in Australian collision sport athletes. A review of the literature indicates that although Australians have contributed to the field, several knowledge gaps and limitations currently exist. These include 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. We conclude that while Australia has had an active history of investigating the neurological impact of collision sport participation, further research is clearly needed to better understand these consequences in Australian athletes, and how they can be mitigated.