Concussions in football; is there cause for worry?

Concussions have been in the news for the past few years, and with good reason; mild traumatic brain injuries can impair cognitive function, social behavior, concentration and if not treated, set up for second impact syndrome. The treatment for any suspected head injury is to see a physician.

If you have seen the news, you may have also seen the results of a study out of Boston University where the researchers evaluate the brains of former football players for a substance known as tau. This substance is more prevalent in individuals that have impaired cognitive and neurological function and is termed Chronic Traumatic Encephalopathy (CTE). The findings in the study of 177 players at varying levels of football participation highlight a few things: of athletes that played in the NFL, 99% have signs of CTE, while only 21% of those that played at the high school level had CTE. Before jumping to the conclusion that playing in the NFL leads to CTE we need to understand the data a little bit more.

First, a diagnosis of CTE can only be done post mortem once the individual has died and their brain has been donated for study. This is termed a convenience sample; the individuals that had their brains donated were probably displaying some cognitive impairment late in their life that led their loved ones to donate their brains. While this is really helpful for researching purposes, it provides a hurdle when drawing comparisons.

Second, there is no comparison group. Typically, researchers match their study group with another, demographically similar group, to determine what differences exist. In this case, there is not a comparison group. So, what is the prevalence of CTE in the general population that did not play football at any level? We don’t know that answer yet.

Third, does this relationship signal causation? It is concerning that 99% of the NFL brains showed signs of CTE, but does that mean that football was the cause? It is too early to tell, but this study is interesting in that it starts to gather data on brains in former athletes. As the data base continues to be populated we can start to identify relationships of CTE and sports, not only in football, but in other sports (contact as well as noncontact), as well. For instance, what is the prevalence of CTE in athletes diagnosed with multiple concussions compared with those that have no concussion history? What is the rate of CTE in hockey, soccer, gymnastics, etc. The more information we have, the better prepared we are to make changes.

Personally, I am interested in learning if rule changes have an effect both on injury rates and long term health. If athletes learn proper technique, get stronger, have limited opportunity for concussions then we should see a reduction in both those areas. While data collection for CTE is still in its infancy, it is too early to draw conclusions regarding the safety of certain sports, including football. As more and more information is gathered we can then accurately identify relationships and make recommendations regarding safe play. Until then, emphasize technique, play safe, have fun and make a decision to play that is based on your personal likes, history, family and medical input.
 
Conclusion:

• NFL athletes in this study have a high prevalence of CTE compared to lower participation groups
• The current data does not demonstrate that this relationship is causal
• Emphasize safe play, proper technique and fun

References:
Mez, J., et. al. (2017). Clinicopathological evaluation of chronic traumatic encephalopathy in players of American football. Journal of American Medical Association, 318(4); 360-370.
Rabinovici, G. (2017). Advances and gaps in understanding chronic traumatic encephalopathy. Journal of American Medical Association, 318(4); 338-340.