Concussions on the Brain in Trinity

Image Credit: Laoise Tarrant

Christine Coffey talks to some of Trinity’s leaders in the area of sports-related traumatic brain injuries about their research and the work being carried out in Ireland.

Sports-related brain injuries are very much present in the public consciousness. Recognition and acknowledgement of the link between repeated knocks to the head and neurodegenerative diseases may have taken a while to reach those sports outside boxing and American Football, but researchers at Trinity have been looking at sports’ related traumatic brain injuries for some time and their ground-breaking work is having a global impact on our approach to brain health.

Associate Professor Ciaran Simms describes the research being conducted by the injury biomechanics research group at Trinity, who had the opportunity to present some of their findings and a ‘traffic light chart for safer tackling’ to World Rugby, rugby union’s international sporting body. “For rugby union, the [group] has used video analysis, staged testing and computational modelling to show that the tackler is at greater risk than the ballcarrier, and that upper body tackles are riskier than lower body tackles for direct head contacts. Further, even in the absence of direct head contact, upper body tackles lead to higher inertial head loading of the ball carrier”. Crucially, this research group does not only provide statistical basis for the widely held anecdotal belief that the tackler is at greater risk than the ball carrier, but also identifies key factors in tackle technique that have “lower propensity to result in HIA (Head Injury Assessment)” in different types of tackles (GJ Tierney et al., 2018). The group have also begun “preliminary work on simulation of shoulder charges and illegal tackles in Gaelic football” but report no significant results as of yet. Simms explains that their work is “primarily focused on safer tackling rather than return to play decisions”. Investment in this type of research seems an imperative step in informing fundemental changes in contact sports and developing cornerstones for safer tackle technique to protect athletes. 

Simms thinks there is a “high general awareness among the public of head injury risks in collision sports, perhaps the perception is even worse than the reality. I think the safety issues are clearly important, but they do need to be considered in the context of the general public health benefits of exercise, but that's not my area of expertise.” Professor Áine Kelly (Physiology/Neuroscience), along with Associated Professor Fiona Wilson (Physiotherapy) and Professor Fiona Newell (Psychology), lead the Trinity research programme assessing brain health in current and retired elite athletes and have “an ongoing longitudinal collaboration, since 2015, with Leinster Rugby and Rugby Players Ireland (the professional players association)”. Kelly highlights some of the benefits of the athletic lifestyle, remarking that “Because we know that physical activity throughout life is good for the brain, these athletes are a very interesting cohort to assess since the exercise they habitually undertake may provide a level of protection against age-related neurodegeneration, independent of concussion”. Kelly, Wilson and Newell “investigate blood biomarkers and cognitive measures of brain health in professional rugby players both during and after their careers”. 

Dr David Loane and his associates are focused on the neuroimmunology of traumatic brain injury (TBI) and related neurodegenerative diseases. “My mission for the group is that we elucidate the pathophysiological mechanisms underlying post-traumatic neuroinflammation, neurodegeneration and loss of neurological function, and to develop novel treatment strategies for neuroprotection and post-traumatic repair that will translate to the clinic for human head injury”. 

The group have implicated so-called ‘NOX2’ (a protein), as an activator of chronic microglia (a type of immune cell found in the brain and spinal cord). Another term used to describe this activation is neuroinflammation, which is linked to many neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. Loane says that their latest data indicates that “inhibition of this pathway at one-month post-injury… arrests progressive neurodegeneration in TBI mice, which suggests the possibility of effective targeted clinical neuroprotection even long after a traumatic insult”. Essentially, that (in mice at least) intervention one month after TBI seems to put the breaks on this particular destructive pathway. The group are collaborating with various other professionals in other disciplines “to translate preclinical research findings from the bench to bedside to improve patient health and recovery after TBI.” 

Other aspects of this field that Loane thinks require further study are “differential responses in male versus female athletes”, how age and time post mild TBI influence “neurological and behavioural outcomes”, and “long-term follow up of retired athletes for effects of mild TBI and neurodegeneration (e.g. dementia)”.  “If in doubt sit it out’ is always my first response” says Loane across all games and points out that sports outside of Gaelic games, Rugby Union, MMA also need to be considered. “Other sports such as horse racing, which has a high incidence of brain and spinal cord trauma, is/should be studied…I am dismayed to see so many people cycling the streets of Dublin without wearing bicycle helmets and adequate lighting and high-visibility gear. Public awareness campaigns to increase helmet wearing in cyclists are urgently needed. Public health awareness about TBI prevention is key to reduce incidence and long-term consequences of TBI in Ireland.”

The team working with Professors Matt Campbell and Colin Doherty were the first to identify a “disruption to the brain’s blood vessels as a key hallmark pathology of chronic traumatic encephalopathy (CTE)”. Many may be familiar with CTE, a neurodegenerative disease associated with repeated traumatic brain injuries (TBIs), from following the NFL or having watched the movie ‘Concussion’ starring Will Smith and based on the work of Dr Bennet Omalu. Campbell details their work with rugby players, MMA fighters, as well as retired athletes, which shows “in both rugby players and MMA fighters that the blood-brain barrier (BBB) is disrupted in the days and weeks post-exposure to repetitive concussive and sub-concussive forces (O’Keeffe et al., 2020)”. Contact sports outside of MMA and rugby where concussion or repetitive head trauma occur are also of interest to Campbell. “In reality, the brain is susceptible to any sport that involves repetitive trauma, so it really doesn’t matter if it’s American football or boxing. The differences may be in the regularity of head trauma between sports, i.e., boxing and MMA will have a lot more than GAA for example”. 

Speaking on the research in this area and how it might play a role in informing how sports handle concussions or TBIs, some of the issues surrounding using data or findings to influence return-to-play protocols and other standards are explained by Campbell: “We don’t have good objective measures yet to determine when return to play is warranted. Ideally, we would have a mix of wearable devices such as sensor-enabled mouthguards in tandem with brain imaging or some other physiological readout that together will allow us to better manage players that receive a brain injury”. Mouthguards (or gumshields, depending on your persuasion) are commonly considered in this capacity as they fit onto your teeth which, being connected to the skull, will give a precise idea of how the head moves in these collisions or impacts. Sensors on helmets or other devices on the skin are thought to move around too much to give precise readouts. Computational models which give an objective measure of the forces experienced in collisions could provide a scale for comparing the severity of impacts, removing the dependancy on player/ backroom staff reporting of concussion symptoms.

As to sports’ approach to research led change, Campbell calls for a united front to “address the hard questions” and “figure out the driving forces that underlie CTE development”. “At present, there is a disconnect between various sports as to how to appropriately deal with concussion. There needs to be more cohesion between sporting bodies and there also needs to be a concerted effort to start funding hypothesis-driven research in the area of concussive brain injuries.  Sporting bodies need to now start funding projects that will figure out objectively what is happening in the brain during and after a concussion or even sub-concussive forces.  There is a link between repetitive head trauma and CTE and other dementias and we need to collectively try to identify the exact causes so that we can intervene when appropriate.”

The passing of Jack Charlton and the spate of recent legal cases against rugby unions infiltrated the sporting consciousness on both sides of the Irish Sea. The flowing tributes to these seminal players were imbued with the subtext of their former teammates reckoning with the uncertainty of their own future neurological health and the wellbeing of their friends. Listening to Johnny Giles discussing the struggles of Nobby Stiles - his former teammate, his sister’s husband, his friend - would cause concern in even the most determined sceptics. Campbell’s call for sporting bodies to collaborate in funding research in this area seems to be sports best bet at tackling this issue. Funding research into early interventions and making contact sports fundamentally safer by implementing research-based change is surely the most logical way forward.