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.
The poster warned that a traumatic brain injury can cause a wide range of short or long term changes affecting thinking, sensation, language or emotions, according to the Centers for Disease Control and Prevention. It also warns that the changes may lead to problems with memory and communication, personality changes, as well as depression and the early onset of dementia.
Earlier, in March 2009, the league acknowledged that careers in the NFL could lead to neurological and mental health problems.
Dr. Wendy Wright, a neurologist at Emory University in Atlanta, said in 2009 that she was pleased to see that the policy that kept players from returning to a game or practice if they'd lost consciousness was more conservative than she expected.
She acknowledged that care needs to be taken when a player's career is at stake, "but when you're talking about protecting the brain from long-term consequences of injury, as a neurologist, of course, I think you can't be too careful."
The New York Times reported that Duerson was the first player to request that his brain be examined after his death for CTE, but that as an active member of the players union, he was likely all too aware of the disease. It's been reported that he believed he had the disease in the months before he died.
In the past, players had been cavalier about playing with an injury, even concussions. In an Associated Press survey of 160 active players in 2009, 30 said they had hidden or played down the effects of a concussion at some point in their careers.
But Dr. Kenneth Perrine, a neuropsychologist at Hackensack University Medical Center in Hackensack, N.J, said players had become more aware of the seriousness of concussions in recent years and more candid about feeling ill effects.
"They realize that this is their profession, this is their game, but it's also their lives, and they want to make sure that they're not going to do something that's going to have a negative impact down the line," he said.
Nowinski said that athletes need to know that they need to see a doctor to be cleared to play after a head injury.
"The brain is far more fragile than we've ever realized," said Nowinski. "When you get a concussion, know your brain needs time to recover before you make the injury far worse."