CTE: Media Continues To Be Ahead Of Science
Causal link ‘scientifically premature’
The absence of cross-sectional, epidemiological, prospective or longitudinal studies on CTE has thus led many of the most respected experts and researchers in the concussion community to part company with Drs. McKee and Cantu, at least on the conclusions that can — and can’t — be drawn so far from the science.
Like Randolph and others, Hazrati said that the preliminary findings of the Canadian study of CFL players “support the need for further research into the link between concussion and CTE as well as the need to expand the research to other possible causes of [tau deposits in the brain] in athletes,” and “point to a critical need for prospective studies with good sampling methods to allow us to understand the relationship between multiple concussions and the development of CTE.”
Indeed, it appears that even Dr. McKee and her colleagues have become more circumspect in jumping to scientific conclusions. In discussing the possible causes of CTE in football players, their most recent study makes frequent use of qualifying language (“may”; “suggest”; “unclear”) in connecting CTE to a variety of possible contributing causes.
Indeed, they essentially concede that the picture, if anything, is even less clear: Our findings, they write, only “suggest that CTE may be related to prior participation in football”; that a high level of play “may be related to” CTE; and that “[s]everal other football-related factors may influence CTE risk and disease severity, including but not limited to age at first exposure to football, duration of play, player position, cumulative hits, and linear and rotational acceleration of hits.” (all emphasis supplied)
Just as remarkable was the backpedaling by McKee on the significance of a 2015 study, widely publicized at the time and prominently featured in a New York Times article (which, interestingly, seems to have since vanished from the Internet), which found that former National Football League players who began playing tackle football before the age of twelve were more statistically more likely to experience long-term neurocognitive impairment than those who began playing after age 12.
Interestingly, nowhere in her 2017 CTE study does Dr. McKee cite to a 2016 study — which, perhaps because it didn’t fit the football=CTE meme, received virtually no attention from the media — in which researchers were unable to replicate the findings of that 2015 study. The 2016 study found no association between age of first exposure to football (i.e. playing football prior to high school) and neuroradiological, neurological, or neurophysiological outcome measures, thus pouring cold water (at least temporarily) on the notion that the earlier an athlete starts playing football, the more likely are their chances of developing later-life cognitive impairment.
In her 2017 CTE study, McKee and her colleagues now admit that it is “unclear” that such later-life cognitive impairment is related to CTE pathology. They also concede that is “unclear if symptomatic hits (concussions) are more important than asymptomatic hits resulting in subconcussive injury”, and that it will be “important for future studies to resolve how different measures of exposure to football and age influence outcome.”
But just before this article went to press, a new study by researchers at BU was published which, like the 2015 study, reported increased risk of long-term neuropsychiatric and cognitive impairment in a convenience sample of 214 former football players (not just those who played in the NFL, but those who played up through high school or college) who began playing football before age 12. Once again, in sharp contrast to the reporting — or, more accurately, lack of reporting — on the 2016 study finding no link between age of first exposure to football, the media’s take on the new study, which suffers from the same self-selection bias as all of the McKee CTE case studies, has been that playing tackle football before age 12 dramatically increases the risk of later-life emotional and cognitive impairment.
Attention to the science
Until fairly recently, the fact that the mainstream of the concussion research community did not share the views of the Boston group, or that many scientists see conducting the debate over CTE in the mainstream media rather than in scientific journals as highly problematic, had not been widely reported.
Some in the media, however, including MomsTeam Institute, have been paying attention to the science all along. In a 2013 interview, for instance, a leading concussion researcher, Dr. Michael McCrea, singled out for criticism a statement by Dr. McKee in League of Denial in which she “really wonder[ed], on some level, if every single football player doesn’t have [CTE].”
Ironically, Dr. McCrea’s criticism was proven right by Dr. McKee herself. While the vast majority of the reporting on her 2017 study focused on her finding that 99% of the brains of former NFL players she and her team examined showed signs of CTE, lost amidst the hoopla was the fact that not every football player whose brain was subjected to pathological scrutiny at the BU CTE Center had CTE, with neither of the two brains of players who stopped playing before high school, and just 3 of 14 (21%) of the brains of those who stopped playing football after high school diagnosed with the disease.
“This is one of those situations where the story has really raced out in front of the science,” McCrea told a reporter for the Milwaukee Business Journal in 2013. He agreed that concussion is a serious injury and the sports industry should take it seriously. But McCrea had a problem with League of Denialusing what he considered speculation that had yet to be proven in clinical research
In an October 2013 article in Deadspin, Matthew McCarthy, a physician at New York-Presbyterian Hospital, wrote about the “puddles of ink” that will be “spilled linking head trauma to chronic traumatic encephalopathy … written by sportswriters who, frankly, don’t understand the science and have long overstated what is actually known about the condition.”
About Zurich 2012’s conclusion (which was essentially carried over unchanged to the Berlin 2016 statement) that no cause and effect relationship had been demonstrated, Dr. McCarthy pointed out that the statement “runs counter to almost everything you have read about CTE, but it received virtually no media attention in the United States when it was released. In part, that’s because it speaks to the far higher burden of proof in the scientific community than the one in the public consciousness. But that’s the point. The popular consensus has far outstripped the science.”
As for Dr. McKee’s statement to NewJersey.com, McCarthy observed that she admitted that, while there was not scientific proof, there was enough evidence to start thinking about making changes. But he wondered whether it is the right thing for scientists to choose “to bang the drum, loudly, even if they can’t be sure of the exact message once we’re listening.”