Evidence shows that another NFL legend had a brain disease linked to concussions

Former NFL quarterback Ken Stabler died in July from colon cancer at the age of 69. However, a report by John Branch of the New York Times reveals that research since then has shown that Stabler suffered from an advanced stage of chronic traumatic encephalopathy (CTE), the brain disease that has been linked to concussions.

Stabler played 15 seasons in the NFL, including ten with the Oakland Raiders, where he led that franchise to their first Super Bowl victory following the 1976 season.

According to the report, Stabler suffered from Stage 3 CTE, on a scale of 1 to 4.

CTE is caused by a buildup of tau in the brain. According to researchers at Boston University, tau is a protein that "forms around the brain's blood vessels, interrupting normal functioning and eventually killing nerve cells." It is believed that CTE can be caused by repetitive trauma to the brain, such as the collisions that occur during football games.

The group at Boston University, led by Dr. Ann McKee, recently announced that they studied the brains of 91 former NFL players and found evidence of chronic traumatic encephalopathy (CTE) in 87 (96%) of them.

McKee, who conducted the examination on Stabler, described his case as "moderately severe,"

"Pretty classic," she told the Times. "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."

Of the more than 100 former NFL players shown to have CTE, Stabler is the seventh quarterback. The list also includes seven Hall of Famers, including Junior Seau and Frank Gifford.

According to Branch, Stabler wanted his brain examined because "his mind seemed to slip so precipitously in his final years."