In articulating the methodology for a sports concussion Consensus Conference and the broad statement it produced, the authors noted that "the end goal of the concussion statement was to provide a simple, clear message and tools that would equip the healthcare practitioner to diagnose and manage concussions in sport."
They succeeded with some aspects, but there is little that's simple or clear concerning the message about potential long-term effects. An accompanying article, published recently online in the British Journal of Sports Medicine (along with the broad statement), examined neuroimaging's potential, as well as cognitive functioning and mental health. But controversial sections focus on the links between contact sports and brain injury.
To be fair, the authors succinctly concluded that "there is an association between these (cognitive) deficits and a history of multiple concussions." They also stated, "Retired professional American football players may be at increased risk for mild cognitive impairment."
But the article otherwise provides little clarity around the potential links, including the one between these sports, their potential for causing subconcussive impacts, and the brain disease of chronic traumatic encephalopathy (CTE). Hence a debate rages on: While the article does not support the hypothesis that playing contact sports can lead to CTE, one co-author and his colleague told MedPage Today they disagree -- noting that a committee supported by international sports associations omitted CTE case studies from its review.
"I'm a little frustrated by the way they continue to view CTE," said Robert Cantu, MD, a neurosurgeon with Boston University's CTE Center and the Concussion Legacy Foundation. "They are trying to poo-poo a tremendous amount of evidence."
The debate over CTE's existence, associations, and causes has sparked politics and cover-up, breakthrough research, and even a Will Smith movie so melodramatic (Tell the Truth!) that he neglected to write an accompanying hit song (or perhaps he learned from Wild Wild West).
Researchers have discovered CTE in the brains of several deceased former pro athletes and believe the research has established causation, leading neuropathologist Ann McKee, MD, to warn the public about it on ESPN in November.
The statement committee recognized recently published CTE diagnostic criteria -- but not that playing football, hockey, etc., can cause young athletes to suffer from CTE or other brain diseases. After reviewing thousands of studies, the committee concluded: "There is much more to learn about the potential cause-and-effect relationships of repetitive head impact exposure, concussions, and long-term brain health."
"I am in no way trying to minimize the importance of CTE -- I think there's a reason for concern there, but I think this needs to be processed a little further," said Geoff Manley, MD, a neurosurgeon with the University of California San Francisco, and the statement's corresponding author. "A lot of these cases have not been definitively diagnosed ... I think more work is needed. I know people get pissed when they hear that kind of thing, but the fact is this is a complicated issue."
"CTE was not glossed over, it was not dismissed," said co-author Julian Bailes, MD, a neurosurgeon with NorthShore University HealthSystem Neurological Institute in Illinois.
While this column appears on a medical news site, I'm not going deep into the science because, years after a landmark story that sparked the Smith film, I still forget what the "E" in CTE stands for.
But examining conflict and alleged conspiracy is my science. The committee included only one CTE expert (Cantu) and one neuropathologist, the review was sponsored and organized by organizations with a stake (including FIFA, the IOC, and International Ice Hockey), and the committee excluded animal and case studies from its review.
"There are no longitudinal studies" of CTE, Cantu said. "That would take decades to do and millions of dollars and definitely needs be done. But if you exclude animal studies and case studies, you can say cause-effect is not proven ... But the fact is that virtually every case has had repetitive brain trauma and that is the only constant with CTE, and data are certainly getting us as close to cause-effect as you can have with case histories. The fair thing to me is to say reporting of head trauma is associated with virtually every case of CTE."
"You've got to look at who were the sponsoring organizations," Cantu added. "I'm not saying that's what caused people to go along with that statement over the objections of folks like myself ... [but] they all have a reason to be pleased if someone can come up with saying there is no cause-effect."
They are "groups that would have liability if there is a cause-and-effect relationship presumed," said former college football player Christopher Nowinski, who co-founded the Concussion Legacy Foundation with Cantu. "If we let the NHL and NFL fund a statement," he added, chuckling, "we would laugh at the statement."
Manley defended the statement; the authors volunteered and had an unenviable task: "I got put in the middle of a lot of different opinions," he said, noting that the sports organizations did not influence the process.
"We need to start capturing people at the time events occur and following them over time," Manley added. "There's no quick fix." The animal studies did not translate to humans, and "what we looked at was more generalizable and less likely to have the kinds of errors you may find in studies with smaller sample sizes."
"I am convinced that there has been only an association thus far," Bailes said, "but at the same time there's a lot we don't know about the prevalence, incidence, compounding factors, genetics," and overlap with neurodegenerative conditions (e.g., Parkinson's disease). "Like all good research, this has raised as many questions as it has answered."
So, research into a disease discovered in boxers a century ago still seems unsettled.
Is it, though? Cantu is hardly an anti-sports hawk; he serves on an NFL safety committee. And while the other authors have never been accused of being Sports/Media Complex lackeys (unlike some of their colleagues and mine), I would feel more comfortable accepting the statement if it were not so ripe with conflicts of interest (a few authors also serve on NFL safety committees in addition to having the aforementioned conflicts).
"It's a simple financial issue. We've got a big problem here, and we are not spending enough money to solve this," Manley said. Bailes concurred.
Find a way to get the money, then, unattached to the Complex (Bailes said he is working on that, this weekend no less). The authors volunteered their time, but they got a free trip to Berlin; they are hardly Marie Curie.
That's my take, but what should practitioners do? "There are currently no competing hypotheses for the cause of this disease [CTE], so it would be prudent to assume a cause-and-effect relationship when considering the opportunity to protect athletes," Nowinski said. "We need to take advantage of the opportunity to prevent this by advising people not to get hit in the head as often, and especially children."
He added: "This is not a public heath document."
That's a bit harsh; by his standards, neither is anything the FDA puts out. As a cynical reporter and Smith fan, however, I can't get jiggy with a document that ignored those case studies; many were published by credible authors in credible journals. And while I believe Manley that the organizations did not interfere, they don't have to. In this field, in 2017, money talks. So please eliminate or at least minimize conflicts of interest.
It is that simple and clear.
Sports Clinic is a blog by MedPage Today staff writer Ryan Basen.