Sport must acknowledge the association between repeated concussions and short-term problems – as well as longer term issues of anxiety/depression, Parkinson’s Disease and dementia
In Ireland, we owe a great debt of gratitude to the O’Driscolls both on the sporting field and off – a contribution exemplified by the expertise and passionate advocacy of Dr Barry O’Driscoll, cousin of Ireland’s most famous rugby outside centre.Barry Joseph O’Driscoll was born in Dublin during the Emergency and qualified in medicine from UCD.
He played rugby for UCD, Leinster, Connacht and Ireland receiving four international caps in total, the first against France in Lansdowne Road in 1971 at full back where he successfully kicked both penalty goals. After his playing career came to an end – and in tandem with his professional practice as a GP in Cheshire – he developed his interest in sports medicine, contributing both to the medical committee of the IRFU as well as becoming medical advisor to the International Rugby Board.
Return to play and the Zurich consensus
In 2008, he attended the third international conference on concussion in Zurich at a time of increasing concern about the problem in sport. He approved of the consensus statement issued at that meeting in which players with suspected concussion could not return to play for three weeks without the explicit permission of a neurologist. “I thought, considering our knowledge and the depth of our lack of knowledge that was a reasonable conclusion to come to, to protect the players,” he explained. However a new directive in 2012 did allow a return to play for professional rugby players subject to a satisfactory five-minute pitch side assessment. This was a retrograde step as far as Dr O’Driscoll was concerned: “I said I couldn’t accept that at all and that’s why I resigned”.
A paradigm in search of evidence
In the absence of a clearly defined causal relationship between concussion and chronic traumatic encephalopathy (CTE), I asked him about post-concussion findings in boxing, and the parallels with other contact sports including rugby. “My old man was assigned to Bellevue boxing, (and there were) some affected boxers in Manchester associated with the whiplash/sponge in the bucket effects”. He acknowledged the association between repeated concussions and short-term problems – as well as longer-term issues of anxiety/depression, Parkinson’s disease and dementia.
“I would be happier if Brian stopped playing”
The ongoing effect on professional athletes, especially those retiring with concerns about these potential effects – as well as the important issue of repeated sub-concussive blows is one of concern for him. One of his more famous quotes in this regard was at the Acquired Brain Injury Ireland ‘Brain Injury in Sport’ conference in the Aviva when he was asked about his nephew’s playing career. He replied: “In a way he’s a complete warrior. You can see that in the way he plays like a number seven as well as being a great runner with the ball but, yeah, I think I would be happier [if he had not continued to play]”.
His concerns certainly echo those in the medical literature, including a review by Huber highlighting the link between cumulative exposure to contact sports and severe protein (tau) deposition in CTE. The implication of these findings is that repetitive head injury, including sub-concussive impacts, may be a primary driver of disease.
The ‘classic’ paradigm – diffuse axonal injury and neuro-degenerative disease
The classically accepted paradigm is therefore that CTE arises as a consequence of linear/rotational acceleration of the brain within the skull. The rapid stretching of vulnerable axons within the white matter disrupts microtubule transport resulting in protein accumulation and axonal swelling. There is a corresponding effect on sodium pump function which causes reduced cognitive processing speed, impaired memory and variable loss of consciousness.
Indeed this cognitive association is confirmed by many studies, including that reported by Hume of 366 former rugby union players in which past participation or a history of concussion was associated with small to moderate neurocognitive deficits.
It is hypothesised that the later neuro-histological findings then arise from changes including calcium movement which releases proteases leading to the accumulation of axonal injury-associated proteins including amyloid-B and a microtubule stabilising protein, tau. Phosphorylation of tau is associated with neurotoxicity, neuro-behavioural deterioration and its sequelae including neuro-degenerative disease, suicide and death, most classically identified at autopsy in boxers as “dementia pugilistica” (DP).
The ‘modern’ paradigm – contact sports and tau phosphorylation
However Gardner, Iverson and McCrory suggest that DP and CTE are in fact two distinct syndromes due to their differing clinico-pathological differences including age of onset, natural history, clinical features, pathological findings and diagnostic criteria. More importantly they point out the absence of significant correlation in the literature between pathologically confirmed CTE, clinical findings and disease progression – contrary to the commonly held view that CTE is a neurodegenerative disease.
Adaptive v neurotoxic changes
Although tau phosphorylation is linked to contact sport exposure, there is some evidence to suggest it may be an adaptive response rather than necessarily neurotoxic. More specifically the evidence does not support a causal link between head trauma in contact sports and neuro-degenerative disease, and not least the decreased risk of suicide in retired NFL athletes reported by Iverson. As Professor McCrory from Melbourne’s Florey Institute said, referring to jockeys whose incidence of concussion far exceeds that of rugby players or even boxers: “Just think for a moment: if the CTE story … is true … we should see an epidemic of jockeys with problems. And we don’t … that’s a clue that the CTE story really has a few questions that we don’t understand yet.”
Pitch side assessment – “a grey area about grey matter”
There are also well-recognised weaknesses in the diagnosis of concussion based on the Zurich consensus, not least its limited sensitivity. Indeed a prospective study from Fuller et al regarding the Rugby World Cup in 2015 illustrated this well with over 20 per cent (5/24) of the players with concussion exhibiting no in-match signs or symptoms.
Primum non noncere (“first do no harm”)
Of course professional and amateur sporting bodies have an important duty of care to their athletes, including those in youth sports including rugby. In the United States the Lystedt law applies in most states which mandates concussion education for parents, players and coaches. The three component parts of this education are (a) a yearly information sheet, (b) complete removal from play where there is any suspicion of concussion and (b) return to train/play only with the consent of a suitably knowledgeable and independent “licensed healthcare provider”.
The importance of these principles was reinforced by Professor Michael Molloy, a colleague of Dr O’Driscoll’s in the joint RCSI/RCPI Faculty of Sports and Exercise Medicine (RCSI/RCPI), when presenting to the Joint Oireachtas committee in relation to Concussion in Sport in 2014: “A person who is concussed may well sound reasonable and sensible initially but then a minute later he or she is confused”. Clearly the benefit of these principles would also address concerns about “Second impact syndrome” as in the tragic case of Peter Robinson’s son, Ben who died in 2011 after being returned to the field three times.
What do you do about the game?
Dr O’Driscoll mentioned the potential role of genetic testing to allow the identification of athletes with a genetic predisposition to concussion – while also highlighting the associated medico-legal and ethical problems with such screening. In fact a recent systematic review has identified several potential genetic markers including APOE (Apo lipoprotein E alleles and polymorphisms), BDNF (brain derived neurotrophic factor), D2 (dopamine receptor), Tau (Microtubule associated protein tau) and Ser53Pro as well as NEHF (neurofilament heavy) genotypic variants.
This review found evidence that supported the use of both the APOE promoter -219G/T polymorphism and the BDNF Met/Met genotype, as these were statistically associated with concussion incidence. Clearly, their applicability will vary from sport to sport. For example, it has been noted that the high incidence of CTE in professional athletes may preclude such screening in American football in particular.
“Ten years from now it will be a very different story,” Dr O’Driscoll said, referring in addition to the clinical applicability of functional brain imaging techniques. These were also mentioned by Dr Éanna Falvey in his contribution to the Oireachtas report on Concussion in Sport. Dr Falvey is the Director of Sports and Exercise Medicine at the Sports Surgery Clinic in Santry and referenced diffusion weight and connectivity scanning as holding much promise.
Concussion research in Ireland
Indeed research is ongoing in Ireland at present with Dr Falvey and colleagues who are prospectively evaluating 200 schoolboy rugby players. The players fill in an online questionnaire before each season as well as a Concussion Passport over the monitoring period. Any injury is followed by assessment at the Santry Concussion Clinic including an Axon Sports Test and the King-Devick Test. This latter test has been shown to improve pitch side assessment by rapid number naming. Additional monitoring tests include blood markers as well as a dynamic assessment of balance, an exercise challenge test, an ICS impulse test as well as activity and sleep monitoring.
Changes in professional rugby
Dr O’Driscoll underscored the changes in professional game: “There are changes in rugby especially … and soccer to a lesser extent. Professional rugby has certainly changed with bigger, faster players and more frequent collisions”. This was confirmed by a report from the International Rugby Board confirming a 10 per cent increase in player weight over the preceding 15 years, a five per cent drop in time for a 10m sprint, as well as an increase in collisions from 160 to 220 per match. Of course, heightened awareness has also had an effect. According to a report from Matthew Cross the reported incidence of concussion in Rugby Union increased significantly from 6.7/1000 player hours in the 2012/13 season to 10.5/1000 player hours the following year. According to the report “the stable incidence of other time-loss injuries and player size over the same period suggests that changes in reporting behaviour, a lowering of the diagnostic threshold and increased awareness have all had a major influence on the reporting of concussion in recent years”.
Dr O’Driscoll raised the importance of individual choice for players, once the educational and regulatory framework was in place. “These issues are really important for rugby families. In addition there is the weight and expectation of the professional game – as well as the need for players to maintain their earnings and stay playing”.
Looking for the man not the space
I asked him if he thought it possible to alter the rules so as to incentivise running for space and/or penalise running at the man? “I think this is a vital point as we should not be (incentivising) players to run directly at the man. And once they are off, they should stay off. Rugby is a worldwide commercial success but what proof are they waiting for? I know it is a difficult issue for the game…of which I am a big supporter and which has an awful lot to offer”.
In relation to concussion, are you optimistic?
“I don’t know if it will ever be resolved in a way as we know so little about who is going to get either short, or more importantly who is going to get long terms problems”. He also referenced similar concerns in newer sports such as MMA. “I have my doubts, you know”.
Dr O’Driscoll is still involved in professional sport. He is on the panel of the National Anti-Doping Panel in the UK, which is an independent tribunal responsible for adjudicating anti-doping disputes in sport. His son, Gary, is also heavily involved in professional sport and is currently the medical director at Arsenal. Dr Gary O’Driscoll represented North England schoolboys and London Hospitals in rugby, and was the team medic to London Irish in 1997 as well as to the Ireland squad at both Under-21 and senior international level. He was the official doctor on two British Lions tours and continues to be a member of the RFU Disciplinary Panel.
The O’Driscoll legacy
“Frank, Brian’s Dad, is my first cousin. We both played for UCD, played a lot of our rugby together. We both got caps in Argentina. Frank had the most remarkable acceleration. He played for Connacht and Leinster, and I played for Connacht with him. He was the quickest man in Irish rugby over 20-25 yards, which is what really matters”.
Will we ever see the likes of Brian again?
“I don’t think so really … but I am biased, of course. He had everything, he created gaps that weren’t there. He was a great tackler as well as having a great step off his feet, great acceleration. I have my fingers crossed for this chap Ringrose, but I don’t think we will see another Brian, he was a credit on and off the field, and is a great ambassador for Ireland.”