Chronic Traumatic Encephalopathy (CTE) is a neurodegenerative disease caused by repeated blows to the head. Researchers examined donated brains of former football players at all levels after they had died. Out of 202 brains, As far as ex-NFL players, who competed at the highest level, 110 out of 111 brains showed post-mortem CTE. The researchers also found CTE in: • 3/14 high school players
• 48/53 college players
• 9/14 semi-professional players
• 7/8 players in the Canadian Football League CTE expert and neurologist Ann McKee commented: "… this is a problem in football that we need to address and we need to address now in order to bring some hope and optimism to football players.”