In a new study carried out by researchers at Boston University (MA, USA) and published in JAMA, post-mortem brain examinations were carried out on 202 deceased former American football players.
In the case series of 202 samples, chronic traumatic encephalopathy (CTE) was neuropathologically confirmed in 177 former players using the NINDS–NIBB criteria, developed in collaboration with the Boston researchers. Diagnosis of more severe CTE pathology was observed to be more common in those with history of playing at college, semi-professional and professional levels; while mild CTE pathology was observed in former high school football players.
The authors conclude that their findings suggest CTE may be related to prior participation in football and that a high level of play may be related to substantial disease burden.
Led by Ann McKee, this Boston University group has been the leading voice in CTE pathology research over the last decade and their work has now culminated in what is the largest CTE case series published to date.
However, this study is subject to limitations. Most importantly, the Veterans Affairs–Boston University–Concussion Legacy Foundation Brain Bank (also based in Boston), from which player samples were obtained, is subject to ascertainment bias with former players and families who have experienced the highest symptom burden most likely to participate in brain donation. Therefore, these findings cannot be extrapolated to the wider American football playing population or used to estimate risk of CTE development.
For more on work on CTE being carried out at Boston University you can listen to our podcast with study co-author Michael Alosco.
For more on pathological diagnosis of CTE in former sports players, check out our video interview with Helen Ling.
Source: Mez J, Daneshvar DH, Kiernan PT et al. Clinicopathological evaluation of chronic traumatic encephalopathy in players of American football. JAMA 318(4), 360–370 (2017)