Hall of Fame finalist Kenny Stabler suffered from CTE before he died of colon cancer at age 69 last summer, Boston University researchers announced Wednesday.
Stabler, an NFL most valuable player who won Super Bowl XI as quarterback of the Oakland Raiders, was found to have Stage 3 chronic traumatic encephalopathy. It was widespread throughout his brain, according to Dr. Ann McKee, who conducted the evaluation.
"There was no evidence of any other brain disorder to explain the difficulties he experienced during life," McKee said.
McKee said Stabler, who played 15 years in the NFL, had "quite severe" damage to the areas of the brain involved with learning, memory and regulation of emotion.
"The cancer took him away, but his mind was definitely in a pretty quick downward spiral," his oldest daughter, Kendra Stabler Moyes, told the New York Times. "I'm grateful that he was still so present, still so there. Because I definitely don't think he would have been in even three more years."
More than 100 former NFL players have been found to have suffered from CTE, including Hall of Famers Junior Seau, Mike Webster and Frank Gifford. After Seau's death and CTE diagnosis in 2012, Stabler told his family he wanted his brain studied after his death, which is the only way CTE can be determined.
"What is interesting about Ken Stabler is that he anticipated his diagnosis years in advance," Chris Nowinski, founder of the Concussion Legacy Foundation, told the Associated Press. "And even though he's a football icon, he began actively distancing himself from game in his final years, expressing hope that his grandsons would choose not to play."
Stabler's family would not be eligible for compensation under the league's concussion settlement, currently under appeal, because his CTE diagnosis came after the April 2015 cutoff date.