Brain and behavior study says brain disease CTE hits athletes differently

TORONTO — A degenerative brain disease linked to repetitive brain injuries, such as concussions in athletes, may initially affect people in one of two major ways: dramatically altering their behaviour and mood or impairing memory and thinking abilities, a study suggests. That disease — chronic traumatic encephalopathy, or CTE — has been found in the brains of deceased professional and amateur athletes, members of the military injured by blasts during combat, and others who experienced repeated head trauma.

TORONTO — A degenerative brain disease linked to repetitive brain injuries, such as concussions in athletes, may initially affect people in one of two major ways: dramatically altering their behaviour and mood or impairing memory and thinking abilities, a study suggests.

That disease — chronic traumatic encephalopathy, or CTE — has been found in the brains of deceased professional and amateur athletes, members of the military injured by blasts during combat, and others who experienced repeated head trauma.

“CTE has only been found in individuals with repetitive brain trauma — concussions and subconcussive hits to the head,” said Robert Stern, a professor of neurology and neurosurgery at the Boston University School of Medicine, who led the study.

“The disease is not injury. The brain trauma sets it off,” said Stern, explaining that post-mortem examinations have shown there’s a progressive buildup of an abnormal protein in certain areas of the brain.

For the study, published online Wednesday in the journal Neurology, the research team looked at the brains of 36 male athletes, aged 17 to 98, and diagnosed with CTE after death.

Most had played amateur or professional football, while the rest had played hockey or were involved in wrestling or boxing. None of the subjects had other brain diseases, such as Alzheimer’s.

Researchers interviewed family members about the athletes, asking whether they had developed dementia, changes in thinking, memory, behaviour, mood or the ability to carry out tasks of everyday living. They also reviewed the athletes’ medical records.

Stern said 22 of the athletes exhibited behaviour and mood problems as their first symptoms of CTE, while 11 were initially bothered by memory and cognitive impairments.

Curiously, three of the athletes did not show any signs of CTE before their deaths, although the disease was present in their brains.

“The people with the behavioural and mood symptoms as their presenting problems started to show those problems at a younger age than the people who had the cognitive and memory problems, who presented their difficulties at a later age,” Stern said from Boston.

For the mood-behaviour group, symptoms first appeared at age 35 on average, compared to an average age of 59 in the memory-cognitive group.

The study found that 91 per cent of those first affected by mood and behaviour changes eventually experienced memory and cognitive decline as well.

However, fewer in the cognition group developed mood and behaviour symptoms throughout their disease: 55 per cent experienced behaviour symptoms and 64 per cent had mood disruptions at some point.

Those affected initially by alterations in mood were more emotionally explosive and depressed than those hit first by memory and thinking deficits, with family members reporting that 73 per cent in the first group were “explosive,” compared to 27 per cent in the second group.

“The most common thing was having a short fuse,” Stern said families reported. “The former athletes just blew up over little things and couldn’t control themselves. So they were described as being out of control. Sometimes that led to being incredibly rageful or verbally screaming or yelling, and occasionally in some people it included physical violence, either to one’s spouse or other people or they got into fights.”

“And in most of these cases, this type of behaviour was completely out of the blue, meaning they were only aggressive on the football field or hockey rink. It was out of character.”

The researchers have no explanation as to why three of the subjects exhibited no symptoms, despite having evidence of CTE in their brains.

One was just 17 at death and his brain was in the first stages of disease; the other two were ex-football players aged 40- and 80-something, both with mild CTE on brain examination. Both had been highly educated and were successful businessmen.

The pair perhaps showed no symptoms because they might have had “cognitive reserve,” Stern speculated.

“Some people have bigger and better brains than others and they have more reserve protecting them against the ravages of an underlying disease,” he said. “We see that in Alzheimer’s disease, too. People with higher education … are more protected not from the disease, but from showing symptoms.”

Dr. Charles Tator, a Toronto neurosurgeon who also studies CTE, said the detailed analysis by the Boston researchers is “good information to have,” but it’s not clear how representative the sample of 36 subjects is of all professional and amateur athletes playing collision sports.

“What percentage of people are going to get this problem after they’ve had repeated concussions? That’s the big question mark,” he said, adding that the study, by its nature, can’t answer that question. “I think that this points out the fact that we are still at an early stage of coming to grips with what is this condition and who is it affecting.”

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Council approved a $3 million grant and a $19 million loan Tuesday to help keep Westerner Park sustainable. (Advocate file photo)
Red Deer city council approves $22M to keep Westerner Park viable after emotional debate

It’s vital ensure future success for the huge economic generator, says mayor

Red Deer Rebels goalie Chase Coward tries to find a loose puck during WHL action at the Centrium earlier this season. (Photo by ROB WALLATOR/Red Deer Rebels)
Changes on the horizon for Red Deer Rebels next season

New coach, roster adjustments among top priorities for Sutter this offseason

Renovations and construction have begun at Red Deer Dream Centre. (Photo contributed)
Renovations underway at Red Deer Dream Centre

Christian-based addictions treatment centre

Red Deer County's municipal planning commission gave approval for a new directional sign for a business located near Elnora.
(Image from Red Deer County)
Red Deer County garden centre and winery gets sign approved

Delidais Estate Winery and DA Gardens is located near Elnora

Alberta Premier Jason Kenney. THE CANADIAN PRESS/Jason Franson
Here is a list of latest COVID-19 restrictions in effect in Alberta

New mandatory health restrictions are now in effect in Alberta. Additional restrictions… Continue reading

André Gauthier is shown in a handout photo. Gauthier, a Canadian geologist who spent six years in and out of jail in Dubai after he allegedly uncovered fraud in a gold company, finally is back home in Quebec City after his release last week. THE CANADIAN PRESS/HO-Detained in Dubai MANDATORY CREDIT
Canadian geologist detained in Dubai for six years is back home after charges dropped

Canadian geologist detained in Dubai for six years is back home after charges dropped

This undated photo provided by the North Dakota Game and Fish Department shows a group of bighorn sheep in North Dakota. Alberta's environment department has known for years that toxins from old coal mines are contaminating populations of the province's official animal, the bighorn sheep. THE CANADIAN PRESS/AP-Craig Bihrle/North Dakota Game and Fish Department via AP, File
Alberta government knew bighorn sheep contaminated with coal mine selenium: scientist

Alberta government knew bighorn sheep contaminated with coal mine selenium: scientist

Prime Minister Justin Trudeau holds a press conference in Ottawa on Tuesday, May 11, 2021. Trudeau is rejecting accusations from Alberta’s justice minister that his federal government is part of a trio rooting for that province’s health system to collapse due to COVID-19. THE CANADIAN PRESS/Sean Kilpatrick
Trudeau rejects Alberta cabinet minister accusation PM wants COVID-19 health disaster

Trudeau rejects Alberta cabinet minister accusation PM wants COVID-19 health disaster

Mourners organize a memorial, Monday, May 10, 2021, outside a mobile home in Colorado Springs, Colo., where a shooting at a party took place a day earlier that killed six people before the gunman took his own life. (Jerilee Bennett/The Gazette via AP)
Police: Man killed 6, self after he wasn’t invited to party

Police: Man killed 6, self after he wasn’t invited to party

Colonial Pipeline joue un rôle de premier plan dans le transport de l'essence, du kérosène, du diésel et d'autres produits pétroliers du Texas vers la côte Est.(AP Photo/Seth Wenig)
Gas stations report shortages as pipeline shutdown drags on

Gas stations report shortages as pipeline shutdown drags on

A taxi drives past the charred remains of a car that was burned during clashes between Indigenous people from Cauca state who arrived to support the national strike, with local residents who do not support the blocking of roads in Cali, Colombia, Monday, May 10, 2021. Colombians have protested across the country against a government they feel has long ignored their needs, allowed corruption to run rampant and is so out of touch that it proposed tax increases during the coronavirus pandemic. (AP Photo/Andres Gonzalez)
42 killed in Colombia protests, human rights agency says

42 killed in Colombia protests, human rights agency says

Minister of Intergovernmental Affairs Dominic LeBlanc speaks during a news conference on Parliament Hill, on Friday, Sept. 18, 2020. THE CANADIAN PRESS/Justin Tang
All parties in the Commons give approval in principle to pandemic election bill

All parties in the Commons give approval in principle to pandemic election bill

Brigadier-General Jennie Carignan of the Canadian Armed Forces joins soldiers during a lunch with Prime Minister Justin Trudeau and Secretary General of the North Atlantic Treaty Organization (NATO) Jens Stoltenberg at Canadian Forces Base Petawawa, Ont. on Monday, July 15, 2019. A parliamentary committee will hear this morning from Carigan,  who was recently tapped to lead the military's efforts to change its culture.THE CANADIAN PRESS/Sean Kilpatrick
Military police chief defends independence; Vance allegedly said he ‘owned’ force

Military police chief defends independence; Vance allegedly said he ‘owned’ force

Most Read