There were striking figures that came out of a legal settlement between the NFL and thousands of former players.
At least 25 percent of retired players can expect to develop some type of dementia -- and much younger than those who did not play.
In Dave Herman's den, the memories run wall to wall, highlights of a decade long career with the New York Jets.
Now 73, he played right tackle during the 1969 Super Bowl.
"I don't remember when the game was over with, but I remember very well because I was lined up against big Bubba Smith," Herman said.
He has a hard time remembering the game because "head slaps" were legal then.
"And so he was slapping me in the head all for 60 minutes. And I woke up after the game, I said, 'Who won?'" Herman said with a laugh.
Over the past twenty years, Herman's wife, Roma, noticed he was gradually developing problems with memory and thinking.
"It's the loss of the special things that we've done in the past," Rosa Herman said.
Neurologist Dr. Sam Gandy of Mount Sinai Hospital in New York, one of Herman's doctors, said the panel who oversaw his case couldn't agree on his diagnosis.
"We were split 3-2 as to whether he had Alzheimer's disease or CTE," Gandy said.
CTE - or chronic traumatic encephalopathy - is a degenerative brain disease linked to repeated head injuries such as concussions.
Abnormal tangles of a protein called tau help make the diagnosis and - until now - the only way to find them was at autopsy.
Dr. Gandy performed an experimental PET scan that can detect the tangles in living patients to try to determine if Herman had CTE. He said the results revealed damage on both sides of the hippocampus, and "the best explanation is it's the recurrent head injury."
Herman's scan was positive for the tau tangles. A different scan had ruled out Alzheimer's. The diagnosis was CTE.
"This is the first time this test has been done in someone with CTE," Gandy said. "We don't have a way to confirm a diagnosis during life until now. And we can now establish the true prevalence and how common this disease really is."
Distinguishing Alzheimer's from CTE is crucial because the underlying brain pathology is different, and a treatment that helps one disorder may not help the other.
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