Dylan Keskinen-Keith missed months of school after he suffered a concussion while snowboarding a year ago. The "A" student had difficulty reading and kept losing his place on the page. He would get severe headaches while working on math problems with tutors at home.
The 16-year-old is much better now, and is back in class at his Ottawa high school. But his father, Duncan Keith, doesn't think his son has completely recovered. He is not surprised by new research that shows that the teenage brain is particularly sensitive to damage from sports-related concussions.
The study, done at the University of Montreal, found that teens showed deficits in working memory for up to a year after their brains were concussed while playing hockey, rugby or other sports. Working memory is the ability to hold and manipulate information for short periods. It's what enables a student to remember the answer from the first step of a math problem and use it in the second step. It is also essential for following a written text. Even a small deficit makes it harder to concentrate and to learn, says Dave Ellemberg, a professor in the department of kinesiology.
His study, published in the journal Brain Injury, is part of a growing scientific effort to understand how concussions affect the developing brain.
In recent years, researchers have gained insight into how concussions change the brains of professional athletes, both in the immediate aftermath of a hit – and possibly long after they've retired from the sport. They are investigating the long-term impact of repeated concussions amid growing evidence they may be linked to an Alzheimer's-like condition associated with personality changes and dementia.
However, very little is known about concussions early in life. Adolescence is a time when many athletes push themselves the hardest, but the new findings suggest it may also be when their brains are most vulnerable to injury.
Concussions, also known as mild traumatic brain injuries, occur when there is a rapid acceleration or deceleration of the head. The brain moves or rotates inside the skull, and different parts of it move against each other. Symptoms include headaches, confusion, amnesia and sensitivity to light or noise that can last days, weeks, or months.
The frontal regions of the brain are especially vulnerable, says Dr. Ellemberg. "These areas oversee executive functions responsible for planning, organizing and managing information. During adolescence, these functions are developing rapidly, which makes them more fragile."
Dr. Ellemberg compared the consequences of a concussion in three groups; children between the ages of 9 and 12, teens aged 13 to 16, and adults. All were male, although he has another study under way involving girls and women.
Half of the 96 volunteers had a concussion within the past year, but Dr. Ellemberg also recruited people who had not injured their brains to be part of three age-matched control groups.
The researchers used a variety of tests to assess memory and other cognitive skills. They also measured the electrical activity of the brain while the volunteers did a computerized task that involves working memory.
The adults, children and teens who had suffered a concussion had less brain activity than the control group, says Dr. Ellemberg.
"The neurons fired significantly less," says Dr. Ellemberg. This was most pronounced with the teens. As well, only the teenagers showed deficits in working memory.
He says the study adds to the evidence that parents and coaches need to learn more about concussions and take them seriously, and that sports should be made safer for children.
Many amateur and professional sports organizations are grappling with how to prevent concussions and make sure athletes of all ages don't continue to play after a brain injury or return to the ice or soccer pitch before they are fully recovered.
Long-time minor league hockey coach Paddy Moore says his son Owen was one of more than half a dozen players on his high-level competitive team in Ottawa to suffer a concussion this season.
Owen, who turns 13 in June, was hit from behind during a game Dec. 19. Since then, he has missed a lot of school. He is sitting out the rest of the season and won't be playing soccer this summer.
"He understands the seriousness of it," says Mr. Moore.
But it is hard for Owen to watch his team play their play-off games, both because he misses being on the ice and he finds the bright lights and noise hard to handle.
Mr. Keith, Dylan's father, says his son has suffered three concussions. The first two were during a martial-arts course in the summer of 2010, followed by the third in March, 2011. Mr. Keith has had several concussions himself, so knows how it feels, but says he was slow to pick up on Dylan's symptoms after his initial injury. He didn't realize anything was wrong until his teenager had difficulty tying his own shoelaces.
"As parents, we need to have more awareness. I've had a couple of concussions myself and I didn't pick up on his symptoms right away, and I should have been able to tell."
Dylan is back on his snowboard, but says he isn't sure if his brain has completely recovered from his concussions.
"You don't know what normal is anymore … All you know is if each day is better than the one before," he says.