Former Bruins enforcer Lyndon Byers, who died in 2025 at the age of 61, suffered from stage 3 chronic traumatic encephalopathy (CTE).

That’s according to the post-mortem brain tissue analysis performed by researchers through the Concussion and CTE Foundation. The Byers family donated his brain to the UNITE Brain Bank at Boston University and Anne Byers, his wife of 18 years, released the results to the public in an effort to raise awareness. She described Lyndon’s heartbreaking deterioration.

“It was hard to see his personality change so dramatically,” Anne said in a statement. “He was so fun and vibrant but towards the end it got to the point where (he) didn’t want to socialize or even leave the house. He battled severe depression, had episodes of hallucinations, and his struggles with short-term memory loss made it difficult for him to navigate the day on his own. I will do whatever I can to make sure nobody else has to watch their loved one deteriorate like that.”

Like many of the men who performed the role, Byers – who possessed a big personality and gregarious sense of humor — was a fan favorite. He amassed 959 penalty minutes with the B’s from 1983-92 and was a member of the teams that went to the Stanley Cup Finals in 1988 and 1990. He finished his NHL career with the San Jose Sharks. According to the release, his on-air role with the “Greg Hill Show,” where he worked at WAAF for nearly 25 years, became more difficult as his cognitive symptoms increased.

“With stage 3 (out of 4) disease like Lyndon Byers had, individuals almost always report cognitive symptoms, and 50% develop dementia,” said Dr. Ann McKee, director of the BU CTE Center. “We thank the Byers family for this contribution to research, which brings us closer to our goal of diagnosing CTE during life and develop effective treatments for those still living.”

Of the 20 NHL players studied at BU’s CTE Center, 19 have had CTE, including Bobby Hull, Ralph Backstrom, Stan Mikita, Bob Probert and Derek Boogard. A 2024 study by the center found that the odds of developing CTE increase by 34% for each year of hockey played.

In the release, Anne Byers criticized NHL commissioner Gary Bettman, who has denied there’s a link between playing in the NHL and CTE.

“The NHL can do better to protect it’s players’ safety,” she said. “Athletes deserve to know what head injuries can do so they can make informed decisions about their bodies and work in an environment that supports their health first.”