Young athletes may be returning to the ice or the field too soon after suffering a concussive blow, according to a new Canadian study that found unexplained changes in the brain can continue for months after a player has been deemed fit to play using conventional tests.

Researchers at Western University’s Schulich School of Medicine compared the MRIs of 17 bantam hockey players between 11 and 14 years old taken 24 to 72 hours after becoming concussed against a set of scans done three months later.

The findings revealed changes related to damage to the wiring of the brain, or white matter -- vital communication lines that could affect vision, balance, and even thought processes if disrupted.

“We don’t yet know if this is a healthy coping mechanism in the brain, of if there will be detrimental effects later in life,” medical biophysics PhD candidate Kathryn Manning told CTV News. “This could be alarming if the brain is no longer able to compensate for this underlying damage.”

While the science is out on the lasting effects, the study’s authors warn that kids are being OK’d for play too quickly after a concussion under existing guidelines.

The study also suggests the risk of so-called second impact syndrome could persist for months in young players after a concussion, risking swelling in the brain, permanent damage or even death, if an athlete is hit again before fully recovering.

“It’s almost a double-whammy,” said Dr. Ravi Menon, a biophysics professor who co-authored the study. “We worry about these developing brains, which are constantly changing as the kids get older. We also know that the brain can heal itself, but it needs to be given enough time. If it isn’t given enough time, and we send them back too early, then they become susceptible to a second hit.”

Those risks permanently benched Satchel Gore after his second concussion.

“People say, ‘Oh you have a concussion. Stay out for a week and then you’re good to go. But that’s not really the truth. It’s a dangerous injury,” Satchel said.

The rules governing when to return a young player to the game after a head injury are strict, but they’re based on tests of memory and balance.

“We believe that these tests, though they may be sensitive to some acute symptoms, may not be sensitive to some of the long-term subtle changes that may be present,” Manning said.

While there is no absolute proof that these persisting brain abnormalities heighten the risk of second impact syndrome, Dr. Menon said parents and coaches need to keep kids sidelined for longer until more conclusive research is available.

“It could be weeks to months longer than we currently think,” he said. “We are probably sending these kids back before the brain has a chance to heal.”

The researchers hope the study's findings will lead to more interest in the effects and prevention of concussions.

They look forward to receiving data from a four-year study based on advanced cognitive testing of a women’s rugby team that will help diversify the current body of research, most of which has focused on professional male football and hockey players.

Until more is known, Satchel’s mother is content to see her son scoring music in the family basement rather than scoring goals on the ice. She hopes more parents will follow her lead in protecting her child’s brain.

“I have seen kids go back on the ice, or the field, when they are nowhere near ready,” Nikki Gore said. “They are throwing up on the field, they are headachy and dizzy. The parents say they are fine. You can’t deny the research.”

With a report from CTV’s medical specialist Avis Favaro and producer Elizabeth St. Philip