Head Bangers

Young, elite-level athletes who have suffered a concussion may have lingering neurological consequences affecting their movement control, according to findings by researchers at York ­Uni­versity’s Centre for Vision Research.

While these athletes typically return to play after a few weeks, they may in fact have sustained neurological deficits that are not detected using standard clinical assessments, found lead researcher Lauren E. Sergio, a professor in York’s School of Kinesiology & Health Science, and doctoral candidate Johanna Hurtubise. Their first study looking at National Hockey League draft prospects with a history of concussion showed that even in this top-performing group there is a small amount of impairment.

The researchers looked at the prolonged difficulty in cognitive-motor integration in 51 athletes who were asymptomatic and medically cleared of concussion. Their performance was compared with 51 athletes who had never suffered a concussion.

Participants in both groups were asked to perform two different tasks on a dual-touchscreen laptop. In one task, target location and motor action were aligned. In the other task, the required movement was not aligned with the guiding visual target and required simultaneous thinking for successful performance. The goal was to determine whether young, elite-level athletes with a history of concussion exhibited impairments. When the athletes had to think and move at the same time, the delay was approximately 50 milliseconds; Sergio says this could be the difference between getting hit on the ice or not.

“We expected their motor skill reserve to accommodate for their concussion history,” she says. “We never suspected that this test would pick up a delayed reaction time the way it did when we used it previously on non-elite athletes. We propose that this type of testing (cognitive-motor integration or CMI) is useful as a return-to-play assessment.”

Sergio adds that standard tests used today only look at cognitive and motor tasks separately and don’t combine the two, which could explain why the athletes passed current tests.

“To be successful in many sports, a player must apply a wide range of cognitive factors to each of their movements within the game,” says Sergio. “In hockey, an example would be passing to one’s teammate on the left while looking and attempting to avoid a body check from an opponent on one’s right.”

Sergio says these results suggest current return-to-play assessments – in which thinking and moving are tested separately – don’t fully capture the functional disability of a concussion. She says more research focusing on their integration is needed.