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.