Researchers studying deceased former football players’ brains found evidence of chronic traumatic encephalopathy (CTE) in 177 among the 202 brains they examined—including 110 of 111 National Football League players.
In the study, published recently by JAMA, Ann C. McKee, MD, of the Boston University CTE Center and VA Boston Healthcare System, and colleagues, examined the donated brains to determine neuropathological features of CTE through laboratory examination and clinical symptoms of CTE by talking to players’ next of kin to collect detailed histories including on head trauma, athletic participation, and military service.
Among the 202 football players (median age at death was 66), CTE was neuropathologically diagnosed in 177 players (87%) who had had an average of 15 years of football participation. The 177 players included: 3 of 14 high school players (21%); 48 of 53 college players (91%); 9 of 14 semiprofessional players (64%); 7 of 8 Canadian Football League players (88%); and 110 of 111 NFL players (99%), explains a media release from The JAMA Network Journals.
Neuropathological severity of CTE was distributed across the highest level of play, with all three former high school players having mild pathology and the majority of former college (56%), semiprofessional (56%), and professional (86%) players having severe pathology.
Among 27 participants with mild CTE pathology, 96% had behavioral or mood symptoms or both, 85% had cognitive symptoms, and 33% had signs of dementia. Among 84 participants with severe CTE pathology, 89% had behavioral or mood symptoms or both, 95% had cognitive symptoms, and 85% had signs of dementia.
“In a convenience sample of deceased football players who donated their brains for research, a high proportion had neuropathological evidence of CTE, suggesting that CTE may be related to prior participation in football,” the researchers conclude, per the release.
Several football-related factors may influence CTE risk and disease severity, including but not limited to age at first exposure to football, duration of play, player position and cumulative hits.
The study’s authors urge caution in interpreting the study’s results, since it used a skewed sample based on a brain-donation program because public awareness of CTE may have motivated the brain donation.
Therefore, CTE prevalence cannot be concluded or implied based on this study, per the release.
[Source(s): The JAMA Network Journals, Science Daily]