Ken Stabler in a December 1976 photo taken during the AFC championship game. (AP Photo/File)

This is an updated version of an earlier post.

Ken Stabler, the former Oakland Raiders quarterback who died last summer of colon cancer, was found to have chronic traumatic encephalopathy during a postmortem examination of his brain.

Stabler, who was 69 when he died, had the degenerative brain disease that has been found in the brains of many former football players and is believed to be caused by repeated blows to the head. A free-wheeling and charismatic player known as “The Snake” during the glory days of the Raiders, Stabler is one of the best-known former players in whom CTE has been found at autopsy. Others include Junior Seau, Frank Gifford and Mike Webster, with the list now over 100 according to the New York Times, which reported the Stabler finding.

The discovery was made by researchers at Boston University, which is one of the institutions studying the brains of former players with the relationship between concussions and CTE still not completely understood. Symptoms can include depression, mood swings, difficulty concentrating and even dementia. Presently the disease can only be determined definitively at autopsy and former players, like Stabler, are increasingly stipulating that their brains be donated for post-mortem study.

“He had moderately severe disease,” Dr. Ann McKee, the chief of neuropathology at the V.A. Boston Healthcare System and a professor of neurology and pathology at Boston University School of Medicine, told the Times. She conducted the examination of Stabler’s brain and found him to have Stage 3 CTE on a 1 to 4 scale, with 4 being the most severe.  “Pretty classic. It may be surprising since he was a quarterback, but certainly the lesions were widespread, and they were quite severe, affecting many regions of the brain.”

Stage 3 symptoms are marked by visuospatial difficulties, more extensive cognitive and memory problems, and apathy. In fact, researchers say that, at this stage, 75 percent of people are cognitively impaired.

The discovery is somewhat unusual in quarterbacks, but Stabler was known for frequently scrambling and took more hits than players at the position typically did. He has been considered three times for the Pro Football Hall of Fame and his name is up for consideration again Saturday when members of the Pro Football Writers of America vote Saturday at Super Bowl 50.

Last week, CTE was found in the brain of 27-year-old Tyler Sash, the former New York Giants player who died of an accidental prescription drug overdose in September.