Doctor: 'No question' that NFL great Ken Stabler had CTE

— -- Former Oakland Raiders quarterback Ken Stabler, who died in 2015 from complications resulting from colon cancer, also suffered from the effects of the degenerative disease chronic traumatic encephalopathy, the doctor who examined his brain told ESPN's Outside the Lines.

After his death on July 10 at age 69, Stabler's brain and spinal cord were donated to Boston University's Chronic Traumatic Encephalopathy Center to support research into degenerative brain disease among athletes. CTE, which is believed to be caused by repeated blows to the head, can be diagnosed only after death via an examination of brain tissue.

Dr. Ann McKee, a professor of neurology and pathology at Boston University, said that after examining Stabler's brain, it was clear he suffered from Stage 3 CTE and that the disease was widespread throughout his brain.

"He had very substantial lesions. They were widespread. They were very classic. There was no question about the diagnosis," McKee told Outside the Lines in an interview broadcast Wednesday. "And in some parts of the brain, they were very well established, meaning that he'd had it probably for quite some time."

A native of Foley, Alabama, Stabler threw for 27,938 yards during his 15-year NFL career, compiling a 96-49-1 record as a starting quarterback and a win over the Minnesota Vikings in Super Bowl XI. He played for the Raiders from 1970 to 1979, winning the NFL MVP award in 1974 and earning Pro Bowl honors four times. He also played for the Houston Oilers and New Orleans Saints before retiring after the 1984 season.

"The Snake" is once again a finalist for induction into the Pro Football Hall of Fame. The class of 2016 will be announced Saturday.

Kim Bush, his longtime partner who met Stabler in 1999, said that in addition to showing signs of all the physical punishment he absorbed to his knees and back over his career, the father of three daughters also started showing signs of cognitive impairment and suffered from headaches as he entered his 60s.

"We talked at length about head injury," Bush told OTL. "And he ... he was certain that what he was suffering was the consequences of playing football. I asked him point-blank, "What are your feelings about that in terms of donating your brain for research and the science?' And that's the night he told me that, "Yeah, I definitely should do that, that's the right thing for me to do."

In addition to the "severe" headaches, Bush said Stabler had some disorientation and forgetfulness, and he even started repeating stories. She said the most obvious thing was that he had trouble sleeping.

"He would say, 'My head is rattling,' Bush told OTL. "And it was. It was, in fact, rattling. It intensified [over the last several years]."

Said McKee: "It really goes along very, very well with what we saw under the microscope."

Among the dozens of football players who have died and been diagnosed with CTE -- including Frank Gifford and Junior Seau -- Stabler is the first prominent quarterback. Typically, quarterbacks don't bang heads as often as other players, but McKee told OTL that the length of Stabler's career definitely played a factor. Stabler also took more hits than the average quarterback as his ability to scramble and create plays on the fly helped revolutionize the position.

"Commonly when we see that amount of involvement ... we are dealing with a person who has substantial memory problems. And that's exactly what he had," McKee told OTL. "... He's a quarterback, but we've found CTE now in every single football position. He played for a very long time. And, you know, that's something that is a red flag for us because in all our studies, we're finding that CTE risk is really associated with duration of playing football.

"He played for 28 years. He began at the age of 9. He played a very long time in the NFL. So it's not really a surprise that he might have developed this disease."

The New York Times also published results of the study.

Bush told OTL that Stabler, known as much for his kindness and compassion as he was for his bravado, accuracy and ability to win games in the clutch, would be glad to know that his decision to donate his brain to science might help others down the road.

"Changes have to be made so that these guys are not forfeiting their brains -- literally, their brains," Bush told OTL. "And the impact, the damage runs across their whole life, from depression to anxiety to, my gosh, some of the guys have committed suicide out of desperation.

"... I just think that there would have been some peace in him knowing what was going on. He would want this science to change this horrible thing that's happening to so many players and find a way to make the game safer and better."