In a sample of 202 deceased players of American football from a brain donation program, chronic traumatic encephalopathy was neuropathologically diagnosed in 177 players across all levels of play (87%), including 110 of 111 former National Football League players (99%).Neuropathological severity of chronic traumatic encephalopathy was distributed across the highest level of play, with all 3 former high school players having mild pathology and the majority of former college, semiprofessionl, and professional players having severe pathology. Among 27 participants with mild pathology, 26 (96%) had behavioral or mood symptoms or both, 23 (85%) had cognitive symptoms, and 9 (33%) had signs of dementia. Among 84 participants with severe pathology, 75 (89%) had behavioral or mood symptoms or both, 80 (95%) had cognitive symptoms, and 71 (85%) had signs of dementia. The study concludes that football playing is highly associated with chronic traumatic encephalopathy brain damage.
Mez J, Daneshvar DH, Kiernan PT, Abdolmohammdi B, Alvarez VE, Huber BR, Alosco ML, Solomon TM, et al.: Clinocopathological Evaluation of Chronic Traumatic Encephalopathy in Players of American Football. JAMA 318(4):360-370 (2017).