Of the five retired NFL players who were recruited for the study, all were 45 years or older and each had a history of one of more concussions. Three players had mild cognitive impairment, one had dementia and one had normal cognitive function. Each research volunteer was clinically screened to gauge their level of depression and cognitive ability. The players exhibited more depressive symptoms than the healthy men and generally scored lower on cognitive tests, indicating diminished cognitive function.
"I'm very, very hopeful that this will be groundbreaking and that we're on the cutting edge of ways to diagnose these conditions without having to wait for autopsies," said Wayne Clark, a former back-up quarterback for the San Diego Chargers in the early 1970s and the study participant with normal cognitive function.
"Ultimately, I hope this leads to rules and equipment that'll make the game safer so more people can enjoy it," he added.
Although the results of the study were strongly positive, researchers stress the results are preliminary and that more research needs to be done on a larger group of people. Still, researchers are optimistic and already say this technology isn't limited to former NFL players.
"This has applications not just for professional and amateur athletes, but for college or high school students, military personnel, and people who have suffered from motor vehicle accidents," said Small.
Dr. Julian Bailes, director of the Brain Injury Research Institute and the Bennett Tarkington Chairman of the department of neurosurgery at NorthShore University HealthSystem, says he envisions two potential applications for technology. The first would be to administer the chemical marker to anyone exposed to head trauma and suspected of having pre-CTE symptoms.
The other way, he added, would be using it "to make a decision about whether an athlete or soldier needs to retire and get out of harms way, if there's a certain amount of tau protein burden in their brain."
Bailes, who was also an author on the study, said some researchers are investigating anti-tau pharmaceuticals, but since they haven't been developed yet, intervention and treatment of CTE -- either with pharmaceuticals, natural dietary supplements, psychotherapy, treatment for depression, and watchfulness by the family -- are still the best chances for suicide prevention.
"A lot of these cases that end in suicide are precipitous -- they're not prolonged with the dragging out of symptoms," said Bailes.
He says that the majority of people who commit suicide are depressed, talk about it, exhibit warning signs, seek treatment and council, or go on antidepressants.
"But in CTE and suicides, as we saw with people like Dave Duerson" -- another former NFL player with neurodegenerative disease who committed suicide -- "and Junior Seau, those cases were without warning," said Bailes.
Duerson, a two-time Super Bowl champion, chose to shoot himself in the chest so that, as he requested in text messages to his family before he died, his brain could be studied for signs of CTE. Three months after his death neurologists at Boston University confirmed Duerson's brain showed "moderately advanced" evidence of CTE.
"While it's great to make the diagnosis at autopsy, the frustration was all the people were dead by that point," Bailes said. "In the very least, if we could find out who has a lot of this tau protein in their brain, you would think we'd have a chance to intervene."