In the world of youth hockey, educating players, coaches and parents about the dangers of concussions has not always been easy. It wasn't too long ago that a player who "had his bell rung" would routinely be sent back on the ice, often after only a cursory check by a volunteer unequipped to recognize concussion symptoms.

Today, that's less likely to happen. There's mandatory training for team officials to help them better recognize symptoms and remove a player from action, even if there is just a suspicion of a brain injury. There is also medical oversight of the athlete's recovery and accepted return-to-play protocols that must be adhered to before any child is cleared to return to the ice.

But the ground is constantly shifting, and new research from doctors at Western University in Ontario casts doubt on existing return-to-play protocols. They've found that young hockey players who suffer concussions can still experience aftereffects even if they feel fine and have been cleared to return to action.

"What we see is damage that is there at the three-month time point, which is long after all of these kids went back on to the ice," says Dr. Ravi Menon, who is the Canada Research Chair in Functional Magnetic Resonance Imaging.

Menon and his team chose to look at players currently participating at the Bantam level (15 years old), which is the first year Hockey Canada allows bodychecking. It's also the year where the number of documented concussions begins to become more prevalent.

He says it was intially hard to attract players and families to participate in the study.

"It depends on where you are in the pecking order of hockey. We first approached the highest-level bantam league players and their parents and coaches were not particularly interested in participating," Menon recalls. "When you probed them on this they thought their kids had a shot at the NHL and they thought, I don't really want a record of concussions should my son suffer one."

Risks unclear

Menon eventually attracted players from a slightly lower level of Bantam hockey to participate. Using detailed MRI scans, he and his team were able to take detailed brain snapshots of players who had suffered a concussion. What they found was damage in the brain's so-called white matter, the cabling that links different parts of the brain together.

On average, the players examined had been cleared to return to the ice within an average 23 days. But according to the scans that were done three months after the concussion, brain damage was still evident even though the players exhibited no outward symptoms. The player's brain scan images were compared to "normal" scans from a control group, where no head injury had occurred.

"Even at the three-month time point there was heightened activity between brain areas [in the players that had suffered a concussion]. This suggests to us that this is really an adaptive response. So the brain is trying to strengthen connections as a way to get around this damage," Menon explains.

"That's what we believe right now. The brain masks the fact that you have damage because it's found alternate ways to process the same information."

Menon says it's unclear what risks this damage poses for players who have been cleared to return to the ice.

"We don't know whether that means they are not good to go inside their brains. We don't know what happens with this damage over a long period. There are people who will recover and are there are people who won't recover. We have no idea yet.

"What we can say is that there is still damage long beyond the time they were told they were good to go."

Enough evidence?

Menon says his team has made some troubling findings that may indicate how the damage could manifest itself in the future.

"Many of the white matter tracts that we see damaged and the grey matter areas they connect are the same areas that are implicated in CTE [Chronic Traumatic Encephalopathy]."

The University of Calgary's Dr. Keith Yeates says Menon's initial findings "raise some concern" about how children are currently being cleared to return to sport but says more work is needed.

"Does it put the kid at risk in any way? Does it have any long-term consequence for them? We don't know. We need to follow beyond three months to see if they are more susceptible to concussions going forward or, if they had another concussion, did it take it longer to recover?"

Until then, there may not be enough evidence to support extending a young athlete's time away before returning to sport.

"There is growing evidence that if we do the return to sport protocols properly, we have drastically reduced and prevented many of the second concussions," Yeates says.

At the same time, Menon says it may be to time re-evaluate some of the return-to-play protocols currently being used. He points out that current models focus on things that can be done in an office setting without any internal testing such as blood work. He acknowledges that doing an MRI on every concussion isn't practical or feasible.

"We can still do bedside tests but we could maybe refine and align them to something that is relevant to the activity we see in the brain," he says.

Menon also acknowledges that applying more stringent return-to-play protocols could mean longer periods sitting on the sidelines for concussed players.

A hard sell in a sport that is just starting to really take concussions seriously.