The biggest hits in contact sports are no longer taking place on the field, but in the pages of scientific journals, reports Dylan Cleaver, in the final of a three-part series.
"Dear James Graham," begins a recent piece by former Wallaby-turned-writer Peter FitzSimons, prefacing an open letter where he praises the St George hardman for engaging in the CTE debate before chiding him for cherry-picking bad science.
It was a culmination of a tete-a-tete between player and columnist, which boiled down to Graham believing the spectre of brain disease as a result of sports injuries has been overstated, while FitzSimons says it's not.
Although the protagonists in this case were high profile and instantly recognisable to the sporting public, there is little difference between their fight and what is taking place in the hallowed halls of medical science academia.
If anything it was more civil.
Through the pages of journals and keynotes in lecture halls, the fight over CTE, or more broadly concussion, is bubbling away. Academic punches have been landed. The protagonists might be scientists but in the background are those two ever-present cornermen - money and ego.
"One of the things that frustrates me is that I see camps," says Bob Cantu, the Boston-based neurosurgeon sometimes referred to as the godfather of concussion. "Once you're there it is very difficult to hold an open view - but it doesn't stop these people popping off about stuff they don't really have great depths of research or personal experience with.
"If your reputation is well earned, people listen to you even if you don't talk about the stuff you got that reputation for."
Cantu co-founded the Concussion Legacy Foundation with former pro wrestler Chris Nowinski. He has a reputation that is gilded but even he has not been immune to criticism from those who believe his advocacy for safety equipment and consultancy with the National Football League (NFL) leaves him compromised.
"I've not been tied to an organisation or an institution for my income or my livelihood per se, so I could say it the way I honestly believed it," Cantu counters.
Cantu is deep into his 70s but is tanned and tennis fit. The foyer to the office he keeps at Emerson Hospital is lined with photos of famous athletes he has treated. They often inscribe the pictures with messages of gratitude.
He speaks with the confidence of a man who believes he'll end up on the right side of history and also with a measurable disdain for those who he believes will not. He peppers the conversation with multiple, "this is not necessarily for writing about, but ..." and will follow it with critiques of people he believes are lazy or deficient thinkers on CTE, including some of the biggest names in the field.
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From Cantu you learn that the grants process that drives medical research has led to unqualified people passing themselves off as CTE experts, and you learn that the international panel of experts (he adds inverted commas here) that comes up with the "Consensus statement on concussion in sport" is, in his opinion, a bit of a sham.
This nugget alone is particularly revealing given his name is attached to it.
"I've been very upset with their statements as regards to CTE and I've let them know that. I disagree with them writing there's no causal link established between repetitive head injury and CTE and leaving it at that … What I [lobbied for] was that while there is not a direct cause and effect between repetitive head injury and CTE there is an overwhelming causal association or causal link between them.
"I could not get it through the powers that be, Paul McCrory and Willem Meeuwisse; they are the two major drivers and that organisation [Concussion in Sport Group] is funded by organisations that have an axe in the grind so to speak." This is the first time the name McCrory is mentioned on my travels through the greater Boston area but it won't be the last.
"Do you know Paul McCrory?" asks Bob Stern, a neuropsychologist and clinician who put together Boston University's grant for funding from the NFL, a process that ended with a senate committee hearing that was utterly damning of the NFL and some in the medical community.
Sterns adds conspiratorially that there are "four guys out there saying really ridiculous stuff" and McCrory, an Australian who consults to the AFL among other sporting codes, is at the top of his list.
"None of them do empirical science. None of them have done a single research study but they've written 12 review papers or policy statements that have focused on CTE and all are negative."
The Herald twice approached McCrory to comment for this story, but neither request was answered.
McCrory is not a fan of the media evidently and on the lecture circuit he has described the focus on CTE as "hoo-ha". Not surprisingly, he's become the go-to guy for sports administrators determined to put a safe face on their sport.
McCrory belongs to a subset of scientists the Boston group describe dismissively as "CTE deniers".
At the very least it should be viewed as curious that McCrory is the chief signatory of sport's concussion consensus group.
Ann McKee, the effervescent neuropathologist who made last year's Time magazine list of 100 Most Influential People, sits in her office in front of a piece of art depicting "The Catch", a famous Joe Montana to Dwight Clark connection that enabled the San Francisco 49ers to beat the Dallas Cowboys 28-27 in the NFL's NFC championship game.
The painting is different, and it takes a while to work out why. The crowd scene behind the action is not actually people but tau protein. It is unsettling, given Clark recently passed away from amyotrophic lateral sclerosis (ALS), a form of motor neurone disease.
"That's 'The Catch', but we didn't get that brain unfortunately," McKee says. "It was not a catch for us. Clark died of ALS and that is a particular interest of mine - the link between CTE and ALS - so that's too bad, we missed it."
They've got plenty of brains though. At one point McKee had worked with 111 brains belonging to former NFL players and found evidence of CTE in 110 of them. When that went public the pick-up in the media was huge.
The science community wasn't as fawning, pointing out the obvious predetermined bias in the samples.
McKee is undeterred by the critics. Where others bristle, she just laughs.
"It was a sequential study of 111 NFL players who happened to donate their brain over an eight-year period and 110 of them had CTE. And they said, 'Well, there's no control group'," McKee says, pealing off another thunderclap of laughter.
"First of all, it's a brain bank series, so yeah, to have a control group we'd have to follow athletes from 18 and up, have some that don't play football and some that are similar in all respects except they play football. We follow them for 70 years and then we do an autopsy on them, that's our control group and in 75 years we'll have that answer.
"It'll be fantastic for all those people who are alive in 2100," she says, still laughing.
McKee is the first to admit the study is the epitome of selection bias, given those families most likely to donate the brains of their loved ones are those who had concerns there was something wrong.
"But still, even with the bias, you don't see this number of CTEs in a brain bank for Alzheimer's disease. It's very rare; it's 2-5 per cent. Then you have a brain bank for football players and it's 99 per cent. Even statistically, the evidence is quite strong. If you're collecting for dementia, it's an uncommon cause, broadly, in the general population of men and women, including people who've never played sports. Then you look at football players, it's a very high percentage. Even the college athletes are at 91 per cent in that study.
"You can split hairs, you can use the studies to say we're blowing this out of proportion but the average 7-year-old knows this is real."
Even acknowledging the inherent biases, others say flaws in the methodology does not insulate McKee from accusations of bad science. The barbs depressed her until she came to the realisation that a phenomenon that sits at the nexus of politics, sports, academic medicine and celebrity was always going to attract publicity, not all of it positive.
"I was told I was doing bad science by the president of the IOC [Thomas Bach]," McKee says. "If I was describing all the things I'd described in a disease like supranuclear palsy, no one would have a problem with it, but because I'm talking about sports, it's [like], 'You're attacking my lifeblood.'
"It bothered me a lot at the start. I was accused of things like I was doing it for monetary gain. There is no monetary gain in this field. They said I was delusional and making this up. I've been accused of confusing it with Alzheimer's disease, of not understanding that it's a normal ageing phenomenon. I've been told it's not a problem with football, it's a problem with me," McKee says.
"I was just trying to get to the truth. It was just a very unpleasant truth."
Not all those who push back are, like McCrory, CTE sceptics. Renowned academics like Dr Willie Stewart have urged caution, writing that media distortion of CTE research - such as the "110 out of 111 NFL players have CTE" headline - was creating a culture of fear that was damaging.
Stewart co-authored a paper titled "Chronic traumatic encephalopathy - confusion and controversies" that outlined the limitations and unanswered questions in the current research. In correspondence to The Lancet , he co-signed a letter under the header of "Primum non nocere: a call for balance when reporting on CTE."
Stewart wrote that misleading reporting - "science by press conference" - could have unintended negative consequences.
"Contrary to common perception, the clinical syndrome of CTE has not yet been fully defined, its prevalence is unknown, and the neuropathological diagnostic criteria are no more than preliminary," he wrote.
The caution is understandable, if unrealistic. Rightly or wrongly the cork has been popped on the CTE bottle and it's not going back in without a struggle, or at least without accusations that sports, and the research institutions that rely on sports for funding, are whitewashing a public health issue.
Lee Goldstein, the scientist who has studied the mechanisms that set in motion the cascade that leads to CTE, is sceptical of those who want to slow down.
"Translate it to your guys," he says, referring to the Herald 's Longest Goodbye feature on five players in the 1964 Taranaki Ranfurly Shield team who were suffering from, or had died with, dementia. "They all played rugby, and they're all getting this dementia but that's just a correlation, it doesn't mean one causes the other. Even if you say you have five cases, they'll say you have to have 50 cases. When you get your 50 cases they'll say, 'Well, you really need 1000 cases.'
"There's no magic number in which a correlation becomes causation. It's just more correlation. You can play that game for 20 or 30 years - this is what the tobacco industry did for decades."
Interrupt Goldstein's musings to point out that it might be in the multi-billion-dollar contact sports' industry to play the long game and his eyes light up.
"Absolu … I didn't say that, you said that, but that is absolutely true because you can never get correlation to prove causation."
Goldstein says he takes McKee's work and moves it on to the next stage. When it leaves her office, the correlation between football and CTE is strong but, as Goldstein points out in inimitable style, no stronger than the fact that every time he drinks his morning coffee, the sun comes up.
"It's a perfect correlation in fact but I remain confident there's no causality there," he jokes.
He sets up experiments using the scientific method in a bid to answer a single question: "Can I show not correlation but causation?"
Goldstein's rodent testing showed mice suffered violent head wobbles imperceptible to the naked eye from forces equivalent to football tackles. Those are the mechanisms, he says, that lead to the pathology McKee sees on her slides. It should be, he points out politely, a slam dunk against their critics.
"There's no perfect way to do this other than to say if Ann's is pointing in this direction, and mine points in the same direction, you're f***ed," he says. "So when detractors say we don't have any evidence we say, 'No, no, no, no, no. You might not agree with my interpretation but you cannot argue with our science.'
"If [our critics] don't buy it, they either have to say I'm lying and making it up, or they have to do an experiment to show me I'm wrong."
That's what really gets to Goldstein and his colleagues: not so much the fact that people doubt their work, because they've spent the past few years trying to "rip apart my own theories", but that their loudest critics use words, not laboratory research, to try to minimise their findings.
For Ian Murphy, who heads up the medical department at New Zealand Rugby, the key is providing "meaningful" information that rugby's stakeholders - from administrators, to coaches, players and, yes, parents - can use.
"We feel our greatest anxiety is not knowing."
Murphy said the way to view the opinion on CTE, its cause and effect, was to think of a pendulum. At one end there are those who believe contact sports are too dangerous and that brain damage is nigh on inevitable; at the other are those who doubt the existence of CTE full stop.
As the research advances, the swings of the pendulum become less and less and, eventually, consensus is reached.
"Because you have uncertainty you have to be cautious, and the precautionary principle is something we live by and that's why we have the rules we have around concussion," Murphy says.
Perhaps, you might say, when there is potential for thousands of people to be affected by a disease that could be easily mitigated with certain rule changes, it is better to be ahead of the science; certainly as opposed to being behind it, which is where the general population was left sitting with the tobacco industry from the late 17th century to the 1990s.
"We don't serve our population well by sitting back with a she'll-be-right, laissez-faire attitude [in the face of] undeniable science. That actually damages your sport in terms of public perception and participation and so on," Murphy says.
"That's our role: we're a rugby organisation that promotes rugby, but in doing so we have an obligation to ensure the safety or welfare of our players is maintained to the greatest extent possible."
While arguments cross the globe as to the veracity of Boston University's CTE research, New Zealand Rugby is quietly establishing its own study into whether its players are at greater risk of neurodegenerative brain diseases than the general population.
Led by scientist Ken Quarrie, they are not lab testing but rather have established a rugby cohort that they can feed into the Department of Statistics Integrated Data Infrastructure (IDI), a huge data bank which holds many types of information.
"It's a complex piece of work. We think it's got good potential to inform us to a greater degree than we currently know in the area of the benefits and otherwise of playing rugby. Because that's essentially the question people want to know the answer to: what, if any, harm is going to come to me from playing rugby long term?"
It's a valid question. The answers will be eagerly awaited. The hardest part might be what to do if they those answers are not ones that anybody really wants to hear.
Follow the money
The multi-billion-dollar business that is USA's National Football League has been accused of soft-soaping the dangers of head injuries upon the revelation that scores of former stars have died with chronic traumatic encephalopathy (and you can safely assume many more are living with it).
One of the flashpoints for this belief came after the NFL tried to siphon $30 million funding away from Boston University towards North Carolina University, whose research it deemed more "friendly" to its cause.
The first pot of money was split between Dr Ann McKee and a research group from New York. The second tranche, $16m, was earmarked for a single grant bid.
It was generally accepted that the strongest bid was the BU proposal to develop ways of diagnosing CTE during life, to understand risk factors and to refine diagnostic criteria.
After a period of silence the BU team learned the NFL had tried to get the second-strongest bid, from North Carolina, funded. That bid was led by Dr Kevin Guskiewicz, who has served on NFL committees.
The National Institutes of Health, which administers funding for medical research, was so disturbed by the politicking that it funded the Boston University research out of its own budget.
"They basically did this to screw the NFL. This was the best science," said Dr Robert Stern, who led the Boston grant bid.
The process was so murky it was the subject of a 91-page Congressional report, which was damning of the NFL's motives and didn't spare members of their medical team.
Dr Chris Nowinski, who created the Concussion Legacy Foundation, who work in close concert with Boston University researchers, said his organisation's relationship with the NFL is "as bad as it's ever been".
"When they tried to defund Bob Stern, that was a line in the sand for me," Nowinski said. "The NFL put out a release saying they've still given the money, but it was just randomly handed out to friends.
"That's where I have a problem. They're not funding CTE work, now they're saying their strategy is to fund concussion work and to fund helmet work to give the perception that this is a fixable problem.
"That is literally going to kill football players."
Dylan Cleaver flew to Boston on a nib health scholarship following a series of award-winning articles on a cluster of former rugby players being diagnosed with dementia.