For teenager Samantha Yurechuk, it started as just another scramble for the puck. She collided with a player, hit her head on the ice and suffered a concussion - unaware the injury put her at risk of mental decline decades later.
As the 14-year-old opened her eyes under the glare of the arena lights two weeks ago today, the trainer of the Brampton Canadettes bantam AA team rushed over, leaned down and asked: "What city are you in?"
"What's a city?" she replied.
"I started to feel nervous," said the Grade 9 student from Orangeville, Ont., about an hour northwest of Toronto. "I started to think there was something wrong."
Samantha, who has fully recovered, is one of the estimated 10 per cent of hockey players who suffer a concussion every year.
On hockey rinks, soccer pitches, toboggan hills and other sporting arenas across Canada, concussions are a known risk of the game. Conventional thinking used to be that athletes who suffer a single concussion bounce back unscathed.
But Canadian research published in the online journal Brain this week found that even one major concussion can haunt sufferers into midlife and beyond through memory decline, poorer motor skills and slower reaction time.
The research is a warning that should prompt hockey parents to re-evaluate the risk they allow their children to take for a game deeply entwined with Canadian identity.
"The effects of concussions have been ignored for the last 40 years," said Louis De Beaumont, the study's author and a clinical neuropsychologist at the University of Montreal.
Adam Wolman, a Toronto real estate broker, didn't wait for a study to tell him that concussions could be dangerous. He was concerned about their effects after his 14-year-old son, Sam, suffered two of them, one severe.
After seeing a specialist, the family adopted the cautious approach and took Sam, who has fully recovered, out of contact hockey a year ago. He now plays house league for fun.
"We didn't want to risk Sam having problems later in life," Mr. Wolman said. "Most of the kids playing select and hockey in the A levels today will continue to play when they are in their 20s. The majority of them will probably play in non-contact leagues and pick-up games. It's unfortunate that there isn't a higher level non-contact option for kids in their teens."
Most parents aren't like Mr. Wolman. Despite the risks, the vast majority keep their children in the game, even after a couple of concussions.
"I'm amazed at what risks people will take in the name of sports. It is mind-boggling," said Brian Webster, a brain injury lawyer based in Vancouver, who hears from parents who want to sue after their children have suffered concussions from sports. "... When you put your children in sports, you should really seriously try and understand the risks and the benefits, and try to minimize the risks without losing the benefits. But don't pretend they're not there."
THE 'SCIENTIFIC FACTS'
The University of Montreal researchers managed to quantify these risks by first tracking down athletic and alumni associations to find subjects: 19 healthy former Canadian university athletes who had suffered at least one concussion in early adulthood and 21 former athletes who had never had a concussion.
The researchers tested the former athletes' motor control, long-term memory and how well they followed simple verbal and written commands. The results were compelling: Those who had concussions had poorer performance in memory tests, delayed responses to unpredictable events and were slower at hand-control tests than those who never had a concussion.
Further research on more patients and the passage of time are required to determine whether concussions cause the more sinister effect of Alzheimer's disease, which leaves a tangled mass of fatty proteins inside a shrunken brain.
Since the study was based on a concussion grading system most Canadian doctors no longer use, some believe the findings may apply only to those who suffered more severe concussions. Still, experts say the study must be taken seriously.
"We had come to think that concussions were a rather benign trauma, but that is not the case," said physician Charles Tator, founder of ThinkFirst, a non-profit organization that educates coaches, parents and children about safe sporting practices. "...Unfortunately, there is no drug, no exercise that has been discovered that has any beneficial effect on concussion. Those are the scientific facts."
To compound matters, Dr. Tator said, physicians aren't always aware of the best way to manage concussions. Wanting to brush off the injury, sufferers may go back on the ice - or the football field or the toboggan slope - unaware they risk a second injury.
"If you have a continuing headache, feel abnormally fatigued, you are not ready to go back," said Dr. Tator, a neurosurgeon at Toronto Western Hospital. "Any one of those lingering symptoms means you have not recovered."
The study results have prompted renewed calls for changes to competitive hockey. Playing four on four, insisting on well-fitting, tightly buckled helmets and wearing softer shoulder and elbow pads - instead of the hard plastic ones - would go a long way toward reducing the number of collisions, injuries and concussions, Dr. Tator said.
"Concussion is a good word," he said. "So long as people make the jump that concussion equals brain injury."
Each year, an estimated 45,000 Canadians suffer a concussion, said Peter Rumney, physician director of the brain injury rehab program at Bloorview Kids Rehab.
What no one can predict, however, is which ones will be left with long-lasting effects.
"Some people get away quite well, others don't," Dr. Rumney said. "We don't have any method right now to know who is going to be lucky."
Dr. Rumney has suffered three concussions: at age 4, when he took a sharp turn on his wagon; at 11, when he was playing defence in hockey; and at 13, when he was tobogganing with his brothers.
Today, he wonders whether those concussions have had any ill effects.
"I'm terrible on names, maybe it was just the way I was built," Dr. Rumney said. "Or maybe it was made a bit worse by the concussions."
Since concussions are an invisible injury - no abnormality typically shows up on a CT scan - doctors are left to diagnose them through symptoms relayed by their sufferers.
Many patients are not even aware that they've suffered a concussion, wrongly believing losing consciousness is the key requirement. In fact, unconsciousness occurs in 5 per cent of concussions - the remaining 95 per cent include any one of about 20 symptoms, including confusion, headache, dizziness, feeling dazed, vomiting and poor concentration.
'IT'S NOT WORTH IT'
Marty Cairns saw his 16-year-old son, Ryan, go flying into the boards at full speed last summer.
"I was the coach at the time, I was up in the stands watching," said Mr. Cairns of his son, who has fully recovered. "I cringe every time he goes into the boards or gets hit. It's a concern to everybody, especially after Sanderson died."
Don Sanderson, a 21-year-old rookie defenceman for the senior AAA Whitby Dunlops of the Ontario Hockey Association, died this month after hitting his unprotected head - his helmet came off - on the ice during a fight.
But William Trudell, a 23-year-old who used to play AAA hockey in Winnipeg, said head injuries have always been a risk of the sport.
"It's a hazard of the game," said Mr. Trudell, who has had 13 concussions from hockey and football, and who suffers from migraines. "You can't have a contact game without somebody getting hurt."
Now a carpenter in Toronto, he suffered his last concussion when he was 21 and playing competitive hockey.
"It was one of those where I am standing up and I thought, 'Wow, this sucks. It's not worth it,' " he said. He now plays house league for fun.
Similarly, 35-year-old Stephen Lepper of Brandon estimates he has had four concussions after skiing and hockey accidents, not including a couple of "blackouts" he experienced playing hockey in his youth.
In June of 2005, he had his last concussion; six months later, he had a seizure. His doctor said the seizure may have been caused by that final concussion.
"I'd probably change a few things if I knew more about the potential consequences of concussions, like how aggressively I played," said Mr. Lepper, who takes medication for seizures. "You can't put yourself in a bubble; you have to kind of accept potential consequences."
Indeed, Mr. Lepper, a sales representative, is keen for his three-year-old son, Luke, to get into the game when he is ready.
Paul Comper, a neuropsychologist and researcher at Toronto Rehab, has seen parents who want advice about whether to pull their children, who have suffered concussions, out of sports.
"My job is to advise that there may be implications cognitively," Dr. Comper said. "It could produce problems emotionally and psychologically because we know there's a propensity for emotional and psychological difficulties following concussion such as depression, personality changes and irritability."
Still, more often than not, parents decide to forge ahead, particularly if there is only one concussion and there has been a full recovery, such as the case with Samantha Yurechuk.
"I feel fine now," said Samantha, hours before her Thursday night practice. "I was so lightheaded; I couldn't get up and walk around too much."
She followed doctors' orders, taking a week off the ice and waiting until she was symptom-free during activity before returning to play.
Others have had much longer periods away from the ice, suggesting that her concussion is far more mild.
Her mother, Judy Yurechuk, sees the concussion as an accident - it was two teammates crashing into one other - and it's the only injury her daughter has suffered in a decade of playing hockey.
But she does have an issue with her daughter snowboarding without a helmet, the wearing of which is apparently deemed uncool by the teenage set.
"I have more fear of her injuring herself that way," Ms. Yurechuk said.
What is a concussion?
A brain injury caused by a blow to the head, face, neck or body that causes sudden jarring.
Signs and symptoms
Not knowing time, date, place
Ringing in the ears
Loss of vision
How long does it last?
Typically, a week to 10 days. In some cases, children take weeks or months to heal.
How is it treated?
Rest is the primary treatment. Children should not exercise, go to school or do any activities that may make their condition worse, such as bike riding, play wrestling with siblings, video games or using the computer. Every child who suffers a head injury should be seen by a doctor as soon as possible.
Not all concussions can be avoided; even helmets can't always prevent a concussion.
However, there are steps that can be taken to minimize risk. These include:
Wear a helmet when bicycling, skiing, horseback riding, tobogganing, skating, skateboarding or when playing contact sports such as football, soccer or hockey. Also when riding a scooter.
The helmet should be of good quality, certified and well maintained.
A properly fitted helmet has a strap buckled tightly, with only one finger able to fit between the strap and the chin.
If you suffer a blow to the head while playing, leave the activity immediately and seek medical