Former Chicago Bears defensive back Dave Duerson, who committed suicide last Thursday, will have his brain matter tested for chronic traumatic encephalopathy at the Center for the Study of Traumatic Encephalopathy at Boston University School of Medicine.
Duerson, 50, was found dead in his Miami home from a gunshot wound to the chest. The former Super Bowl champion had sent text messages to his family requesting that his brain be tested for the disease after his death.
"He told me he loved me very much and he was truly sorry and that he loves the kids," said Alicia Duerson. "And that he thinks there was something wrong with his brain on the left side and for me to please get it to the NFL."
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The degenerative brain disease has been linked to repeated head trauma, and it has become more common among football players, some as young as 18 years old.
"Essentially, your brain actually starts falling apart because you've been hit in the head and 10 to 20 years later start getting symptoms, memory problems, emotional problems and eventually it leads to dementia," said Chris Nowinski, co-director of the center.
Family members say that Suerson recently began having vision problems and had trouble forming words.
"He was a brilliant man, never had a problem with spelling, or words, or putting words together," said his ex-wife. "He was a very educated man and he was experiencing blurred vision and formulating words and spelling. Dave's vision was perfect, you know, his whole entire life."
CTE begins when a protein that's a normal part of the cell becomes toxic and starts slowing down the cell's ability to function.
"It's like a sludge," said Nowinski. "This toxic protein starts a process in the brain, spreads cell to cell. Eventually when you lose enough brain cells these symptoms start to appear."
The disease has also been associated with cognitive problems and in some cases, depression and loss of impulse control.
Also known as punch drunk syndrome, the disease has been most associated with boxers. However, in recent years it has shown up in professional and college football players, and in one pro hockey player.
"Football players are at very high risk because they take, studies show, about a thousand hits to the head," said Nowinki. "One thousand hits is something we've never really done before with athletes, and we're learning it might be too many."
Duerson's family just wants him to remembered for advocating for his fellow athletes.
"I would like all his fans to know that David was a very loving caring man, and he always thought of others before he thought of himself," said Alicia. "Even in this moment, by him wanting his brain to be examined and treated and so he could possibly help other football players in the future."
The NFL has attempted to crack down on head injuries in recent years. In 2009, the league created rules for when players could return to the field after suffering blows to the head. Players showing any of several symptoms, even if they remain conscious, must be benched for the rest of that day. They also cannot return to practice or play until cleared by the team physician and an independent neurological consultant.
Later, in August 2010, posters were distributed in locker rooms to warn players that head injuries could have lifelong consequences.