41% of contact sport athletes who died young had CTE, Boston University study finds

A new Boston University CTE Center brain bank study has found that more than 40% of contact and collision sport athletes who died young had CTE.

The BU Chronic Traumatic Encephalopathy (CTE) Center study released on Monday details more than 60 cases of CTE diagnosed in athletes under age 30, including the first American woman athlete diagnosed with CTE.

Among a brain bank sample of 152 young athletes exposed to repetitive head impacts (RHI) who died when they were under 30 years old, 41.4% (63 athletes) had neuropathological evidence of CTE — a degenerative brain disease caused by RHI.

“This study clearly shows that the pathology of CTE starts early,” said corresponding author Ann McKee, chief of neuropathology at VA Boston Healthcare System and director of the BU CTE Center.

“The fact that over 40% of young contact and collision sport athletes in the UNITE brain bank have CTE is remarkable — considering that studies of community brain banks show that fewer than 1% of the general population has CTE,” McKee added.

The UNITE Brain Bank is the largest tissue repository in the world focused on traumatic brain injury and CTE. The brain bank contains more than 1,400 brains, including over 700 brains that have been diagnosed with CTE.

The new study published in JAMA Neurology includes the first American woman athlete diagnosed with CTE, a 28-year-old collegiate soccer player whose identity remains private.

Nearly all the young athletes had mild CTE, stages 1 and 2. Three donors had CTE stage 3; there are four possible stages of CTE, with stage 4 being the most severe. In those with CTE, there was often other evidence of brain injury.

Clinical symptoms were common among the athletes, whether or not they had CTE. Clinical symptoms included depression (70.0%), apathy (71.3%), difficulty controlling behaviors (56.8%), and problems with decision making (54.5%). Substance abuse also was frequent, with alcohol abuse present in 42.9% and drug abuse in 38.3%.

“The study suggests that some of the symptoms these young athletes are experiencing are not caused by the early tau pathology of CTE,” said McKee. “It is imperative that young athletes who are experiencing neuropsychiatric symptoms seek out care, as it is likely that the symptoms can be reduced with effective management and follow-up.”

Amateur athletes comprised 71.4% of those diagnosed with CTE, and included American football, ice hockey, soccer and rugby players, and wrestlers.

Those diagnosed with CTE were older (average age at death 25.3 years vs. 21.4 years), and had significantly more years of exposure to contact sports (11.6 years vs. 8.8 years).

CTE cannot yet be diagnosed in the living, and the true prevalence of CTE in any population remains unknown.

“This study highlights the importance of assessing the symptoms and clinical presentation of CTE in living athletes who have sustained repetitive head injuries,” said Nsini Umoh, program director for traumatic brain injury research at the National Institute of Neurological Disorders and Stroke. “While additional research in this area is needed, these findings are a notable addition to the body of research on CTE.”