Boston University researchers examined deceased American football players who were diagnosed with chronic traumatic encephalopathy, in a study published in JAMA.
Researchers analyzed 202 deceased football players' brains for neuropathological and clinical features. The football players participated at different levels of play.
Here are five key points:
1. Of the 202 players, 177 were diagnosed with CTE.
2. Of the 111 NFL players evaluated, 110 were diagnosed with CTE, reflecting a 99 percent portion.
3. Eight-six percent of the professional football players had severe pathology.
4. Of the 84 players with severe CTE pathology, 89 percent suffered from behavioral or mood symptoms. Additionally, 95 percent had cognitive symptoms and 85 percent had dementia symptoms.
5. Researchers concluded, "a high proportion [of the players] had neuropathological evidence of CTE, suggesting that CTE may be related to prior participation in football."