SAN DIEGO - A groundbreaking study is linking concussions sustained by NFL players to Alzheimer's disease.
Former San Diego Chargers player Wayne Clark knows about concussions. He took a bad hit during his time as a Chargers quarterback in the early 1970s.
"Unlike other concussions, you may feel a little starry-eyed, but you'll have a general idea of where you are and so forth," said Clark. "This was rather extreme. I just had no recollection of the whole day."
Clark recently took park in a innovative study at UCLA allowed doctors and scientists to perform tests on five living former NFL players that had previously been done during autopsies.
The five professional athletes had at least one serious concussion during their careers.
"This is the first time we've been able to image football players' protein deposits that we've observed in people with Alzheimer's disease," said Dr. Gary Small with UCLA's Brain Research Institute.
Protein linked to Alzheimer's disease showed up as green, yellow and reds in brain scans.
Clark's scan showed areas of yellow, green and red, compared to a brain with no concussion, which showed no color.
"When I first saw the scan, I thought, 'That looks pretty extensive,'" said Clark.
Last month, a different study confirmed former Chargers linebacker Junior Seau had a brain disease caused by repeated head trauma.
UCSD neurologist Dr. James Brewer said this latest study is a promising start to future research.
"What it does is allow us a sense of saying, something is wrong here," said Brewer. "There's lot of protein building here. We know that protein can be harmful."
Experts hope this new testing will mean early detection and treatment for football players at the professional and collegiate levels.
For more on the study, click here.