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Recent media articles spell out the risks of sports-related head injury and returning to play too early.

“…the league [NFL] is again under scrutiny, this time over how some of those doctors diagnosed a head hit to quarterback Tua Tagovailoa of the Miami Dolphins two weeks ago. After holding his helmet, struggling to get up and falling again, Tagovailoa was taken to the locker room, examined and allowed to return to that game.” [New York Times, 7 Oct 2022]

“….return to that game” is the critical phrase here.

Steve Thompson, who was a hooker for England when they won the Rugby World Cup in 2003….is among players including Ryan Jones, the former captain of Wales, who believe that the sporting bodies were negligent in allowing training that involved repeated head trauma and insufficient recovery time.” (The Times, 12 Oct 2022)

And there’s the second critical phrase: “insufficient recovery time”.

Vickie Shim (right) at the Auckland Bioengineering Institute is working with Professor Paul Breen and Associate Professor Jorge Serrador from the MARCS Institute for Brain, Behaviour and Development at Sydney Western University. Their goal is a world-first algorithm for a safe return-to-play timeframe after initial head impact.

“Missing a few games can be a big problem for sportspeople, but because head injuries aren’t visible, contact sport still isn’t taking this problem seriously,” says Shim.

She says we need reliable biomarkers to predict the period of increased brain vulnerability after mild traumatic brain injury (mTBI) which can then tell players when it’s safe to return to the game. “In other words, a decision-making tool for coaches and parents to help keep players safe,” says Shim.

The statistics are sobering. Up to 90 per cent of cases are mild yet many patients report long-term impairments. Those playing contact sports are at high risk of suffering multiple concussions which contribute to chronic neurological injury and neurodegenerative disease. The brain is very vulnerable after the initial head impact, and subsequent insults before it has recovered may compound the damage. For some sportspeople, the injuries can be catastrophic.

This is where Breen (left) and Serrador (below left) come in – they’re leading experts in CBF in concussive settings. They have been researching CBF in American football players and athletes where there have been notable cases of sportspeople having to retire early with brain injuries or early onset of neurodegenerative diseases such as Alzheimer’s and Parkinson’s.

“We believe cerebral blood flow (CBF) may be a key marker and a key mechanism in the uncoupling of the CBF and brain metabolism where the resulting lack of energy and oxygen leads to increased vulnerability,” says Shim.

Together with Breen and Serrador, Shim will expand an earlier one-year longitudinal study of 40 rugby players in Gisborne using bespoke mouthguard sensors to measure head impact history, advanced MRI to show any brain structural changes and tests to identify any altered cognitive functions. This dataset showed structural changes in players’ brains which were not recovered post-season.

The MRI phase will be done in collaboration with Gisborne’s Mātai Medical Research Institute which offers an advanced MRI facility providing fine detail on brain function and structure.

“We’ll monitor changes in their CBF throughout the season using a mobile ultrasound CBF device and correlate the data with the number of head impacts and use MRI to analyse any structural changes in the brain of the players during the season. A machine learning algorithm will then take over the data to help predict the period of brain vulnerability,” says Shim.

Shim and team propose to extend their MRI data fusion algorithm to identify players at risk of developing persistent symptoms from their head impacts and provide a safe ‘return-to-play’ timeframe for them.

“We’ll extend the current dataset to another team of 28 rugby players, building a digital library of their brains using their MRI scans and measuring damage patterns of the brain after head impacts. We’ll correlate this with the CBF data to monitor how long the brain remains vulnerable after head impacts. The outcome will be a machine learning based digital health care platform that can identify players at risk of developing long-term impairments and provide a safe ‘return-to-play’ timeframe.”

That platform will also benefit clinicians. “By quantitatively estimating recovery times, we can help clinicians to determine treatment and management pathways rapidly and objectively, reducing both clinical workloads and subjective decision-making.

This project will progress Shim’s earlier research on TBI using a smartphone app that could quickly check a player before and after a hit to the head which we featured in MedTech Bites in 2019.


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