A pioneering Boston University study has discovered early signs of brain damage in young athletes, potentially altering the perception of risks in contact sports. The research shows that repetitive head impacts cause brain injuries well before the onset of CTE.
A new study led by researchers from Boston University Chobanian & Avedisian School of Medicine has revealed that young athletes may exhibit early signs of neurodegeneration before the onset of chronic traumatic encephalopathy (CTE).
The study, published in the journal Nature, examined frozen human brain tissue from 28 men aged 25 to 51, categorizing them into three groups: those with no contact sports history, those exposed to repetitive head impacts (RHI) through contact sports but without CTE, and contact-sports athletes with low-stage CTE.
The researchers detected significant brain cell loss, inflammation and vascular damage in athletes who had experienced RHI, even if they hadn't been diagnosed with CTE.
"These results have the potential to significantly change how we view contact sports. They suggest that exposure to RHI can kill brain cells and cause long-term brain damage, independent of CTE," corresponding author Jonathan Cherry, an assistant professor of pathology & laboratory medicine and director of the digital pathology core at the BU CTE Center, said in a news release.
The study's findings point to a 56% loss of neurons in the cortical sulcal depths, regions subjected to the highest mechanical forces during head impacts and where CTE typically begins.
This neuron loss appeared in all the athletes, suggesting that significant brain damage occurs long before traditional markers of CTE are detectable.
"You don't expect to see neuron loss or inflammation in the brains of young athletes because they are generally free of disease. These findings suggest that repetitive head impacts cause brain injury much earlier than we previously thought," Cherry added.
To explore the earliest changes wrought by RHI, the researchers employed single nucleus RNA sequencing techniques, comparing brain tissue from athletes with varying exposure levels to contact sports.
The results were scrutinized against larger datasets and previously published research, confirming the link between RHI and early brain degeneration.
"This groundbreaking study shows that repetitive hits to the head, including concussions and the more frequent non-concussive impacts, cause brain damage in young people even before CTE. These findings should serve as a call to reduce head hits in contact sports at all levels, including youth, high school and college," added co-author Ann McKee, a director of the BU CTE Center and the William Fairfield Warren Distinguished Professor of Neurology and Pathology at BU.