Dave Duerson, a former NFL player who committed suicide in February, had "moderately advanced" brain damage related to blows to the head, according to the researcher who made the diagnosis.
"It's indisputable" that Duerson had chronic traumatic encephalopathy, a disorder linked to repeated brain trauma, Dr. Ann McKee said Monday.
Just before ending his life he left a note telling his family that he wanted his brain tested. He specified it was to be by the Center for the Study of Traumatic Encephalopathy at Boston University's School of Medicine.
Duerson played safety in the NFL for 11 seasons, seven with the Chicago Bears including the Super Bowl year of 1985-1986 and was chosen for four Pro Bowls before retiring in 1993.
Duerson's case was "moderately advanced," McKee said. "The likelihood is that if he hadn't had the CTE, he wouldn't have developed those symptoms that he was experiencing at the end of his life and perhaps he wouldn't have been compelled to end his life."
Duerson had at least 10 concussions in his NFL career, according to his family, and lost consciousness during some. However, he never was admitted to a hospital for them, Stern said. But he said it's also important to address hits to the head that don't cause concussions.
CSTE, created in 2008, is a collaboration between the BU School of Medicine and the Sports Legacy Institute, headed by Chris Nowinski. The center has been aggressively researching head trauma in sports, and has received a $1 million gift from the NFL, which it has pushed for better treatment of concussions.
Nowinski said "the latest version of the NFL's guidelines [on concussions]are well thought out. And, I think, with the state of the science today, it's about the best we can do."
But he said the problem starts much earlier, in youth football.
"The 6-year-olds are playing the same games as the pros when we know that their brains are far more susceptible to this damage," he said. "My next focus is how do we change youth football so that a kid doesn't show up in the NFL with 10,000 hits to their head already?"
"It's amazing to me that we have pitch counts in youth baseball to protect children's elbow ligaments," he said, "but we do not count how often we hit them in the head to protect their brains."