AANS Neurosurgeon | Volume 26, Number 1, 2017

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Counterpoint: The Pediatric Health Crisis is Not Concussions

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Athletes, particularly those participating in contact sports, may be exposed to repeated blows to the head raising the concern that such exposure might lead to neurological dysfunction later in life. In the last few years, there has been a drumbeat of press coverage suggesting that this is a problem of such magnitude that it should be considered a health crisis causing parents to become increasingly wary of allowing their children to participate in contact sports.

The dominant narrative at present goes something like this: There are an ever-increasing number of contact sports-related brain injuries that put participants at substantial risk of developing neurodegenerative diseases such as chronic traumatic encephalopathy (CTE), amyotrophic lateral sclerosis (ALS) and other dementing illnesses. Even players who never had a witnessed or reported concussion may fall victim to CTE, sometimes at a very young age. Those athletes with prolonged exposure, such as National Football League (NFL) players, are at very high risk of developing CTE and other neurodegenerative diseases leading to dementia, depression, violent behavior, suicide and early death. The NFL was aware of this risk but, analogous to the big tobacco companies, chose to deny the harmful effects of their product. Furthermore, professional athletes in other sports may also be at considerable risk for developing CTE.

Severity of the Situation
Let’s take a deep breath and assess the veracity of this narrative. While it is true that the annual number of reported sports-related concussions has increased, this does not mean that there are more sports-related brain injuries occurring now than in the past. First, the criteria for diagnosing a concussion have changed considerably. The definition of a concussion used to require a loss of consciousness, but now requires only a change in neurological function after a blow to the head. Most of the concussions reported today would not have met the criteria for concussion in the past. Therefore, it is impossible to say if the number of concussive and sub-concussive blows that occur in athletic activities has increased, decreased or stayed the same.

What is clear, however, is that there is much greater awareness among coaches, trainers, parents and athletes about the potential risk of sub-concussive and concussive injury today than there was in the recent past. These episodes are also treated very differently now. In regard to the sport I know best, American football, there are more stringent return-to-play rules, new recommendations for limiting contact in practice, rule changes that reduce the risk of concussion during game play, a much greater willingness of players and their parents to report concussive symptoms and improved helmet technology. Taking all of this into consideration, if sports related concussions are now a crisis, they must have been a plague of truly Biblical proportions in the past.

However, sports-related concussions were not considered to be a crisis a few decades ago, and there is no reason to consider them a crisis today. A crisis atmosphere is good for readership, viewership, grantsmanship, fundraising and obtaining large settlements or jury awards, but it is not ideal for dispassionate evaluation of the data and good decision-making. The presently available epidemiological data do not support the existence of a concussion crisis.

Compare and Contrast
A long-term study from the Mayo Clinic (1) that assessed whether or not high school football players were at increased risk of neurodegenerative disease deserves more attention. In this study, students who played football between 1946 and 1956 were compared to their classmates who participated in the band, glee club or choir. Both groups were followed for decades to see if the football players were more likely to develop neurodegenerative diseases later in life. This study, published in 2012, did not show a correlation between playing contact sports and any neurodegenerative disease. There was no significant difference between these two groups in regard to dementing illness, Parkinson’s disease or ALS. In other words, in regard to neurodegenerative diseases, playing clarinet was as dangerous as playing linebacker during high school. Considering the low level of concern about concussions and the primitive protective equipment available in this era, it should be reassuring to know that no long term neurological consequences of playing high school football could be found.

How about those with greater exposure? A second study published in 2012 compared long-term health outcomes of thousands of former NFL players to age- and race-matched controls in the general population (2). The NFL cohort demonstrated a decreased overall mortality rate. They were also less likely to commit suicide than the controls. If playing in the NFL reliably results in CTE, and CTE manifests itself in players who take their own lives, among other things, we have some explaining to do. 

Headlines Direct the Message
These data have rarely been discussed in the press. However, those parts of the study that fit the prevailing narrative – playing football results in delayed neurological dysfunction – received a great deal of media attention. The media’s take-home message was not that NFL players lived longer and committed suicide less often than controls but that there was “a nearly threefold rate of neurodegenerative disease-related deaths for the NFL players.” This sounds apocalyptic. You have to read the article pretty carefully to determine that there were 17 total deaths from neurodegenerative disease in this cohort of almost 3,500 former players (~0.5 percent) or that neurodegenerative disease was the cause of death in only about 5 percent of the 334 deceased players. Had the headlines read, “Former NFL players have 5 percent risk of dying from neurodegenerative disease,” the response would likely have been different than the response to the headlines that state that “CTE has been found in the brains of 90 of 94 NFL players and 45 out of 55 college players whose brains were examined.” 

These kind of headlines leave the impression that almost all athletes who play college or professional football will develop CTE. They do not mention that selected samples like this tell us very little about the incidence of CTE in football players. If the brains were donated because the former players had symptoms suggestive of CTE, it is not surprising that a high incidence of CTE would be found. These findings reveal nothing about the thousands of players who do not have such symptoms. 

In addition, it is becoming increasingly clear that one of the histological hallmarks of CTE, the deposition of tau proteins in the brain, occurs frequently as part of the normal aging process in patients without cognitive symptoms (3). Suppose I were to collect a series of marathon runners who had developed severe knee pain leading to total knee replacement. I evaluate the resected knees and find evidence of severe degenerative arthropathy which I designate as Chronic Traumatic Arthropathy (CTA). I find that 90 of 94 marathoners who had these symptoms and donated their knees had these findings. From this, I deduce that nearly all long-distance runners will develop CTA and recommend that high school students should not go out for the cross-country team because of the risk of delayed CTA. I hope I would be roundly criticized for such sloppy thinking and world-class conclusion jumping.

What Side Effects?
In regard to the NFL as the sports equivalent to the tobacco companies, I must confess that I am astonished that intelligent people make this analogy. The tobacco companies collect money from millions of people who use a product that harms their health. There are considerable financial gains that accrue to hiding data on the adverse health effects on the consumers of their product. The NFL collects money from advertisers and millions of people who watch their games. Aside from the adverse health effects of sitting on the couch, drinking beer and watching mind numbing commercials, I do not believe there are significant adverse health effects on the consumers of the NFL products. 

In addition, the analogy between smoking tobacco and playing contact sports is a very poor one. There is overwhelming data that smoking tobacco is associated with a large number of serious adverse health effects – without any offsetting benefits. Conversely, there is limited data that participation in contact sports may be associated with a modest increased risk of delayed neurological deficits – with a long list of offsetting benefits. Of course, the plaintiffs’ bar would like nothing better than to portray the NFL as the equivalent of big tobacco in hopes of getting the same kind of payoff. This will not stop with the NFL. Any deep pocket is a target for picking, and you can anticipate other professional sports leagues, the National Collegiate Athletic Association (NCAA), individual teams, colleges and universities to be hit with innumerable suits related to the “adverse effects of sports-related brain trauma.” 

Recipe for Disaster
We have taken a little bit of science, added a large portion of media hype, thrown in some very sloppy reasoning and a couple of hidden agendas, stirred vigorously using the plaintiffs’ bar and created a truly toxic brew. This is the recipe that has produced the perception of sports-related brain injury as a “crisis” affecting American youth. This perception is inaccurate and dangerous. I fear the perceived risk of delayed neurodegenerative disease will have a significant negative impact on youth participation in sports.

Although the presently available data have not established a causal relationship between sub-concussive repetitive head trauma and delayed neurodegenerative disease, the prevailing narrative in the media makes it seem like letting children play contact sports is a terribly dangerous thing to do, and parents are becoming increasingly concerned about letting their children participate. This is a tragedy because we have a real youth health crisis in the U.S. – childhood obesity. Limiting opportunities for vigorous exercise will only make this real crisis worse.

Childhood obesity rates in the U.S. have tripled in the past 30 years, and it is now estimated that more than one in three children in the U.S. are overweight or obese. This is a real crisis as obesity leads to health problems such as diabetes, heart disease, high blood pressure, high cholesterol, asthma and sleep apnea. It is also clear that obese children and teenagers are more likely to become obese adults. The crisis of childhood obesity – unlike the mythical concussion crisis – is real and of great magnitude. Every time we convince a parent or child that it is too dangerous to play football, soccer or lacrosse or to get on a bicycle without dressing up like Sir Lancelot, we risk making this real crisis worse.

Disclosure: In the interest of full disclosure, Dr. Harbaugh reports that he is a member of the NFL’s Head, Neck and Spine Committee and has served on its Injury Surveillance Committee. He receives no compensation of any kind from the NFL.


References

1. Savica R, Parisi JE, Wold LE, Josephs KA, Ahlskog JE. High school football and risk of neurodegeneration: a community-based study. Mayo Clinic proceedings. Apr 2012;87(4):335-340.

2. Lehman EJ, Hein MJ, Baron SL, Gersic CM. Neurodegenerative causes of death among retired National Football League players. Neurology. Nov 6, 2012; 79(19):1970-1974.

3. Elobeid A, Libard S, Leino M, Popova SN, Alafuzoff I. Altered proteins in the aging brain. J Neuropathol Exp. Neurol. 2016 Mar 15. (Epub ahead of print)

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