CTE in Football and Impact Sports
Posted on 10/6/2017 by Melissa Bloom, P.T., DPT, NCS
Cooler temperatures, students returning to school and the start of another football season are all the telltale signs of fall. And with football back, reports of concussion will inevitably follow. While advancements continue to be made in regards to concussion prevention and treatment, the long-term effects of head trauma, specifically chronic trauma encephalopathy (CTE), remains a huge concern.
You may have previously heard of CTE from the movie “Concussion,” or even from recent media reports. CTE is a tough topic for me. My trouble with the conversation is that there are a lot of unknowns and uncertainties. With the potential for serious injuries, there is the chance for panic and decisions made on emotions versus science. Moreover, ignoring the conversation leads to misinformation. So, it’s time we talk about CTE; what is it and what it means for the future of football.
What is CTE?
CTE is a progressive neurodegenerative disease associated with repetitive head trauma. CTE involves cellular pathological changes similar, but different, to Alzheimer’s disease. The buildup of Tau protein in the brain causes cell death, atrophy and abnormal functioning. CTE can currently only be diagnosed after death by examining the brain under a microscope.
Symptoms can be physical, involving gait abnormalities and slowness of speech, or psychiatric and behavioral, including personality changes, depression and aggression. Various cognitive and processing deficits are also common with CTE, including difficulty thinking, concentrating and remembering.
One consistent scientific challenge is understanding the extent to which age-related changes, psychiatric or mental illness, alcohol or drug use, coexisting dementia or other unknown factors play a role in developing CTE. Currently, this is largely unknown and has not been accounted for in research. CTE is more common in contact sports, but other factors in these athletes may also lead to the disease.
Recent Study and Media Interviews
Earlier this year, the Journal of American Medical Association released an article on CTE. The study looked at participation in American football along with multiple physical and psychosocial variables, and they compared these factors to diagnosis of CTE. Results of this study travelled across the media quickly, with the overall conclusion that players of American football may be at increased risk for CTE. Of the 202 individuals in the study, they found 177 were diagnosed with CTE. The researchers further concluded that 99 percent of subjects who played in the National Football League (NFL) were diagnosed with CTE. What a headline.
Not to downplay the severity of CTE and valid concerns that exist about it, but I want to discuss some limitations about what we can take from these results. First, they conducted their study with football players whose brains were donated for research of CTE, creating a significant selection bias. It was known that their brains would be studied regarding a possible connection with CTE and their participation in contact sports. Individuals and their families who participated (i.e., donated their brain) may have noticed symptoms consistent with CTE prior to death, which led to their participation.
What trends did they find?
Beyond the expected motor, cognitive and psychological involvement known to accompany CTE, there were other notable trends. Substance abuse was noted in 67 percent of those diagnosed with mild CTE, and 49 percent in those diagnosed with severe CTE.
The presence of co-morbid neurodegenerative diseases was also common, including Alzheimer’s, Lewy Body Dementia (LBD) and other motor neuron diseases. In fact, more than 19 percent of the subjects with CTE presented with LBD alone. The current study was not designed to determine the impact these factors had on the development of CTE.
Even the authors note that caution must be used in interpreting the high frequency of CTE in their sample. Their results do not allow for estimates of prevalence, due to the lack of comparison groups. Additionally, the sample population was not representative of the overall population of former players of American football. The majority of players only play youth or high school levels, but most individuals in this study played at the college or pro level.
Evidence supports an association between long-term cognitive, neurobehavioral and psychiatric problems with participation in contact sports, such as football, boxing, soccer, etc. While it seems plausible there is a connection between CTE and repetitive impacts seen with American football, it is currently not possible to determine the causality or risk factors with any certainty. We need to proceed cautiously and collect additional research. However, concussion screenings and efforts to minimize concussion can improve the current health of players even if the long-term effects are unknown.
There is an inherent risk with contact sports for concussive and sub-concussive impacts. The challenge now is evaluating the risk given uncertain long-term consequences and the many scientific questions we don't have answered. For now, let’s continue to play smart, wear protective gear, get baseline tested for concussion and, should a concussion occur, thoroughly go through the rehabilitation process for safe return-to-play and activity.
Melissa Bloom By: Melissa Bloom, P.T., DPT, NCS. Melissa is a physical therapist with Physiotherapy Associates in Atlanta, GA. Melissa is a board certified neurology specialist. She specializes in vestibular rehabilitation and concussion management and teaches nationally on both topics.
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