I saw that...then read the article. Later on it gives a caveat saying how ALL the brains tested were donated and were ALREADY SUSPECTED OF HAVING CTE.In other words, that "study" is completely worthless as proof and the author should be castrated for the intentional and grossly misleading title.
It's very likely football leads to an increase in the occurance of CTE, but nowhere remotely close to "95.6%".
There is not strong evidence to date to even make this claim. It is possible. But, asymptomatic individuals with no known concussion history show evidence of tau deposition on autopsy. There is not an established link between concussions and CTE. There is not an established dose dependent relationship (i.e., more concussions = greater risk and/or more widespread pathology). It is not known what the base rates of CTE are in the general population or in individuals with high blood pressure or steroid users or diabetes or Alzheimer's disease or drug dependency or depression. We do not understand if there even is a clinical profile for CTE and how that progresses.What we know is that a large lab in Boston is securing millions upon millions of dollars to conduct case series studies of brains and soliciting families of former NFL players (and others, but football has been the primary source) to donate the brains of their loved ones. Some families agree to this, others do not. Thus, there is an inherent problem with possible selection bias here. Families who observed unusual behaviors in their loved ones, for example, might be more inclined to donate than families who do not observe such behaviors. Ultimately, this is the problem when relying on case reports instead of systematically studying the phenomenon in question, because in this case especially, the case series model fails to answer the question if concussions cause CTE or even if CTE is causing the behavior change. (We might, for example, one day decide to autopsy the brains of 100 plumbers whose families expressed concern about unusual behavior and find 90% show elevated tau deposition and/or other brain abnormalities, which might lead folks to conclude that being a plumber increases the risk of a neurodegenerative process...which is awfully flimsy interpretation of data).
Ultimately, there no strong epidemiological evidence to support any of this yet, but it's alarming stuff, it fits a good narrative for the media, and as such, holes in the story don't get addressed. Which is why most in the neuroscience community remain agnostic and even a bit skeptical about all this. Doesn't mean further research (preferably from a lab independent from the Boston group who has an enormous vested interest in arriving at one conclusion versus another) won't eventually support the concussion--CTE connection. It's just that the narrative has far outpaced the science.
ETA: Does anyone know if these findings have been subject to peer review yet? Or did McKee's group go straight to PBS first?
