Former Patriots star Mosi Tatupu likely suffered from CTE

Five years after he died of a heart attack at age 54, studies of brain tissue preserved from former New England Patriots fullback Mosi Tatupu's autopsy revealed irregular tau protein buildup, the calling card of chronic traumatic encephalopathy (CTE), a disease researchers believe stems from repetitive head injuries. 

Tatupu, a star and fan favorite for the Patriots during the '80s, showed many of the hallmark signs of CTE before his death. In his final years, depression, memory loss and alcohol abuse were a constant reminder of the repeated blows to the head he sustained over a 15-year NFL career.

"To this day, I can't stand the sound of the equipment hitting together," Tatupu's former wife, Linnea Garcia-Tatupu, told The Boston Globe. "If I knew then what I know now, would I have encouraged Mosi's dream? Would I have encouraged Lofa's dream? I wouldn't have. The risk is not worth the reward."

Tatupu's son, Lofa Tatupu, also played in the NFL as a linebacker for the Seattle Seahawks for six seasons. 

The family donated brain tissue from Mosi's 2010 autopsy to the CTE Center at Boston University last year, in hopes of finding an explanation for the perplexing decline in his health in his last years. 

The CTE Center has so far discovered signs of CTE in the brains of 140 deceased athletes. 

Repetitive head injuries are believed to contribute to a change in brain chemistry that causes tau protein buildup, "preventing the brain’s nerve cells from making normal connections with each other, eventually killing them," according to The Globe's report.

In August 2013, the NFL settled with 18,000 former NFL players for $765 million to compensate them for brain injuries sustained during their playing careers.