Analysis of brain tissue from athletes who were exposed to RHIs and died before the age of 30 revealed neuropathological evidence of shrinkage of the brain and microscopic changes that indicate a breach of the blood-brain barrier. The case series also identified the first known American female athlete with CTE.
Nearly all of those with CTE had a mild form of the disease and 71% played only at the amateur level in youth, high school, or college sports.
“A lot of people think CTE is a result of high-level, professional play such as football, ice hockey, and boxing, but it can affect amateur athletes and can affect people at a young age,” lead author Ann McKee, MD, professor of neurology and pathology and director of the Chronic Traumatic Encephalopathy Center at Boston University, said in an interview.
The findings were
A rare look
Brain donation at younger ages is rare, so most of what is known about CTE comes from studies in older athletes.
“We’ve always known that young people could develop this disease early after just amateur high school, youth, and college exposure, but this is the largest study of donor brains at this age,” Dr. McKee said.
The case series included 152 brains of athletes who played contact sports, experienced RHIs, and died before age 30. The tissues are part of the Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) Brain Bank and were donated between February 2008 and September 2022.
Researchers reviewed the donors’ medical records and conducted retrospective interviews with the donors’ next of kin to assess cognitive symptoms, mood disturbances, and neurobehavioral issues.
Donors died between the ages of 13 and 29 years, 92.8% were male and 73% were White. In 57.2% of the cases, suicide was the cause of death, with no difference between those with or without CTE.
CTE was neuropathologically diagnosed in 41.4% of athletes, using diagnostic criteria developed by the National Institute of Neurological Disorders and Stroke.
More than 95% had mild CTE. Diagnosis was associated with older age (mean difference, 3.92 years; P < .001) and significantly more years of exposure to contact sports (11.6 vs. 8.8 years).
Among those with CTE, 71.4% played amateur sports, including football (60.9%), soccer (17.2%), hockey (7.8%), and wrestling (7%).
The cohort includes the first known American female athlete with CTE. Recruiting female brain donors has always been a challenge, Dr. McKee said. In this study, females comprised about 7% of the entire cohort and tended to be younger and play fewer years of a sport, compared with their male counterparts. All of that could lower their risk for CTE, Dr. McKee said.
“We don’t have enough brain donations to make any comments about differences between the genders, but we’ve always known that women can develop CTE,” she said. “It’s been reported after domestic violence and in an autistic woman who was a headbanger, so it was just a matter of time before we found our first case.”