Football Head Impact Intensity Linked to CTE Risk
The cumulative number and force of blows to the head that American football players suffered were associated with chronic traumatic encephalopathy (CTE), an analysis of autopsy data has shown.
Players who have spent more time in certain positions with higher levels of exposure to linear and rotational acceleration may face a greater risk of CTE, said Daniel Daneshvar, MD, PhD, of Massachusetts General Hospital. , co-author of research presented at the Alzheimer’s Association 2022 International Conference.
Defensive backs seemed to face the highest risk due to the types of blows they face on the pitch, Daneshvar said. “We can now potentially target interventions to reduce people’s risk by reducing the number of blows and the force of the blows,” he said. MedPage Today.
The CTE is associated with a history of repeated impacts to the headincluding those suffered in contact or collision sports such as American football and boxing, and is neuropathologically diagnosed. Previous research on soccer players has also linked dementia in CTE to repetitive head impact exposure.
In their analysis, Daneshvar and his colleagues studied 656 former American football players who died at an average age of around 60. Most (69%) had CTE pathology and all had donated their brains to the Veterans Affairs-Boston University-Concussion Legacy Foundation Brain Bank. .
Relatives of the players provided details of the players’ tenure and positions in youth, high school, college and professional football.
From a literature search of studies using helmet accelerometers, the researchers calculated the average hit frequency, linear acceleration, and rotational acceleration for 1 year of play at each level-position combination. These values were combined with each player’s occupational exposure to determine cumulative head impact frequency, cumulative linear acceleration, and cumulative rotational acceleration.
Each cumulative measure was significantly associated with the presence and severity of CTE (P
Cumulative rotational acceleration, which had an area under the receiver operating curve (AUC) of 0.765, and cumulative linear acceleration (AUC 0.758) performed significantly better than years of play (AUC 0.716) in classification of CTE pathology. The results were similar for the severity of CTE.
The findings suggest that head impact intensity is an important factor in the development of CTE pathology, the researchers said.
Strategies to reduce head impacts include delaying the onset of tackling football in school-aged players and reducing the number of hits and strength level during practice, which may represent both third of the impacts, Daneshvar noted.
This analysis is impressive but has significant limitations, observed Keisuke Kawata, PhD, of Indiana University Bloomington’s School of Public Health, who was not involved in the research.
“Validity is definitely low when it comes to this type of study” because it relies on helmet impact data which is often flawed, Kawata said. MedPage Today. “But it’s a good start.”
Linemen aren’t necessarily the most at risk, and some wide receivers take more hits, Kawata said. “The team’s style of play, the coach’s style and philosophy, as well as individual aggression play an important role in exposure to head impact,” he pointed out.
Going forward, “this current research will not and should not influence the rules and politics surrounding football as it needs to be validated and replicated in different methods and designs,” Kawata noted.
“On the other hand, many studies are testing ways to mitigate overexposure to head impacts, whether by reducing the length of summer camp or eliminating two-day practices,” he said. added.
The study was funded by the National Institute on Aging, National Center for Advancing Translational Sciences, Department of Veterans Affairs, Department of Defense, Alzheimer’s Association, Nick and Lynn Buoniconti Foundation, Concussion Legacy Foundation, Andlinger Foundation and World Wrestling. Entertainment.
Daneshvar and Kawata did not disclose anything.