Longer careers in hockey are linked to greater risk of CTE: study

The largest study ever done on the brains of male hockey players has found the odds of getting a neurodegenerative disease caused by repeated traumatic brain injuries increases with each year played.

The research out of Boston University CTE Center narrowed in on 77 deceased male hockey players — from the high school level to the NHL— and concluded that the likelihood of having chronic traumatic encephalopathy (CTE) increased by 34 per cent each year played. Scientists also found that none of the players who played hockey for fewer than six years had CTE.

“Ice hockey players with longer careers not only were more likely to have CTE, but they also had more severe disease,” said author Jesse Mez, co-director of clinical research at the CTE Centre and associate professor of neurology at Boston University.

The study was published on Dec. 4 in the journal JAMA Network Open.

Of the 77 players' brains researchers studied, more than half had CTE.

Most pros had CTE

Of the professional players examined, 96 per cent had CTE, including 18 of 19 players in the NHL.

Forty-six per cent of college, juniors and semi-professional players presented CTE pathology.

About 10 per cent of youth and high school players had CTE.

Among enforcers, they found 18 of 22 had CTE but noted the difference between players who were enforcers and non-enforcers were not statistically significant after considering years of play.

“We did see the odds increased by two for being an enforcer,” said Mez. “This isn’t something that’s just affecting enforcers. This is affecting a fair amount of the hockey players we studied.”

CTE is a neurogenerative disease. The symptoms resemble Alzheimer’s, but researchers say the disease is caused by repeated traumatic brain injuries and is most often found in former athletes of contact sports. It has also been found in military veterans. There are cognitive symptoms like memory loss, trouble thinking and problem solving.

Some patients may be aggressive or impulsive, said Mez.

The NHL has repeatedly disputed a link between CTE and hockey.

Last month the NHL players association announced an advisory committee to better understand CTE and concussions.

'Losing your loved one bit by bit'

Earlier this year, the family of Bob Murdoch — a two-time Stanley Cup champion and NHL Coach of the Year — announced the Boston University CTE Centre posthumously diagnosed him Stage 3 CTE, as well as Lewy body dementia, mild Alzheimer’s disease and ALS.

To the hockey world, Murdoch was a champion, coach and player.

To Bev Murdoch, his wife of 37 years, he was her world. In his years of decline, she was his caregiver.

“It's like you're losing your loved one bit by bit over time,” she said, adding she intuitively knew her husband had CTE, but it can only be confirmed postmortem. She didn’t expect to learn he had ALS.

“It was quite a surprise to see how much had gone on. It just wasn’t about CTE. But was it CTE that caused all these things?”

Murdoch said she and her husband were motivated to donate his brain to help future generations understand what playing hockey over a long period of time can do to one’s brain.

“I think because there was such a lack of understanding of the illness, and the NHL in particular was not accepting that playing hockey at the pro level or any level for a long period of time could cause this kind of illness,” Murdoch said, who praised the recent move by the NHLPA to form its committee and the NHL Alumni association for its role in helping families.

She hopes the research released this week from Boston University CTE Centre helps raise awareness about the disease—for players, families and medical professionals.

“The more awareness out there, the better,” Murdoch said.