NFL Player CTE Study: Making Sense of the Alarming Results (Part 1) - THE PULSE
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NFL Player CTE Study: Making Sense of the Alarming Results (Part 1)

NFL Player CTE Study: Making Sense of the Alarming Results (Part 1) October 3, 2017Leave a comment

The prevalence of concussions in football has always been a looming threat for the long-term sustainability of the NFL. And while the NFL continues to fight an uphill battle in their quest to eliminate the both the physical risks and emotional concerns related to concussions, it seems as if that hill just keeps getting steeper and steeper…

Earlier this summer on the evening of Tuesday, July 25th, old and new media outlets each took to their respective news platforms to write, report, post, react, tweet, and re-tweet the seemingly shocking findings from a scientific study which examined the brains of hundreds of deceased former football players.  Below are a handful of those headlines from a few publications you may recognize:

  • The New York Times: “111 NFL Brains. All But One Had CTE”
  • LA Times: “CTE was nearly ubiquitous among former NFL players who donated their brains to science”
  • USA Today: “CTE diagnosed in 99% of ex-NFL players studied by researchers”
  • CNN: “CTE found in 99% of studied brains from deceased NFL players”

With the NFL continuing to dominate the professional sport’s popularity contest, combined with the uproar caused by the league’s “concussion conundrum” (refer to the 2015 box office hit “Concussion” starring Will Smith), it’s no surprise that this quickly turned into the top trending story in the New York Times the following Wednesday morning on July 26th.

Fast forward two months later and just as the PR whirlwind was beginning to subside, another CTE bomb was dropped on the NFL. The autopsy report of Aaron Hernandez – former New England Patriots tight end who committed suicide after being acquitted of double murder last April – revealed extremely high amounts of CTE in his brain. Despite being just 27 years of age, the autopsy detected similar levels of CTE as what is typically found in former NFL players well into their 60s.

So, unless you were stuck under a rock buried deep inside a cave this summer, odds are you’re already aware of the dark concussion cloud hovering over the NFL and football in general.  But depending upon your level of expertise in the not-so-elementary field of neuroscience, your first reaction upon reading the aforementioned headlines was likely the same as my own – “Wait, what the hell is CTE?”

What is CTE?

According to the Google machine, CTE – or “Chronic traumatic encephalopathy” in excessively long scientific form is: “A degenerative disease caused by repeated blows to the head”.

The phrase “degenerative disease” isn’t exactly intuitive, but “repeated blows to the head” make it rather obvious how CTE might be connected to football.  The montage below brings back fond memories of the one-year I played organized tackle football back in 7th grade…

According to CNN’s report, “consistent episodes of head trauma (refer to above) can cause a buildup of abnormal tau protein in the brain.  This buildup can then disable neuropathways and lead to a variety of clinical symptoms, including memory loss, confusion, impaired judgment, aggression, depression, anxiety, impulse control issues and sometimes suicidal behavior.”

So here’s what we know so far: 1) the root cause of CTE resembles a common occurrence in the game of football AND 2) the disease itself can lead to a variety of complications spanning a wide range of severity – but these factoids are trivial for the medical and scientific community.  What they care about – and what all parents of both current and prospective football players should care about – is how to derive a clearer answer to the following three questions:

  • Question 1 (Part 1): Given the many activities and sports that are also capable of contributing to long-term CTE development, how much blame does football actually deserve?
  • Question 2 (Part 2): Given the vast range of potential consequences attributable to CTE development, how often do severe symptoms emerge? In other words, how many years of football until serious signs of CTE development begin to appear?
  • Question 3 (Part 3): What legal ramifications, if any, could the NFL and other football organizations potentially be facing down the road?

Part 1: Given the many activities and sports that are also capable of contributing to long-term CTE development, how much blame does football actually deserve?

Dr. Ann McKee, director of Boston University’s CTE Center and co-author of the study, has a definitive answer to this first question.  “There’s no question that there’s a problem in football”, McKee said in a follow-up interview. “People who play football are at risk for this disease.”

McKee didn’t just stay at a Holiday Inn Express last night – the exhaustive list of her research publications would take Will Hunting weeks just to scroll through them all.

However, her repeated research efforts over the years have not come without criticism and those voices can now be heard louder than ever.  The most common rebuttal she receives from skeptics in the medical and scientific community centers around the way in which the recent study, as well as the vast majority of her studies, have been conducted.  Specifically, the samples used in testing were NOT randomly selected – they were contributed directly by families of these deceased former football players.

The red flag raised from this sampling approach is that those families who volunteered for the study may have been more likely to submit their relative’s brain based on actual symptoms they observed when that player was alive.  There was no comparison group tested from either a randomly selected sample of ex-football players or a randomly selected sample of other athletes in general to help isolate football’s impact on CTE development.

McKee is not blind to these shortcomings in her research – this self-awareness is evident in a 2013 interview with Frontline, which was a follow-up to a prior research effort.

“Even this vague assertion isn’t news. There’s no way to know the prevalence of CTE without a means of testing living players.  An autopsy series is terribly biased.”

Daniel Engber of provided an insightful follow-up analysis to how we can interpret the results of McKee’s work. Engber points out that McKee’s study in 2013 examined the brains of 35 former professional football players and found that 34 of them – or 97 percent – displayed signs of CTE development. Given that detection rate from a relatively small sample size, she estimated at the time that the lower bound for CTE’s prevalence in former NFL players is roughly 10 percent.  In other words, we can be confident that CTE build-up is present in AT LEAST 10% of all ex-professional football players.

So by connecting the dots between the 2013 study and the recent study released this summer with over 100 players involved, Engber states that we can assume the actual percentage of NFL players who develop CTE is somewhere between 10% (the lower bound of confidence derived from McKee’s 2013 estimations) and 99% (the CTE prevalence found in the most recent study).

Yes, your gut reaction is spot on – that is a gargantuan range.

This lack of certainty shows us that despite the tireless and noble efforts of McKee and many other researchers in the field, significant work still remains in order to more precisely hone in on football’s role in CTE.

Stay tuned for Part 2 and Part 3



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