York University concussion experts report that young elite-level athletes who have suffered a concussion may have lingering neurological consequences that affect their movement control.
While young athletes typically return to play after a few weeks, researchers at York University’s Centre for Vision Research say these athletes may in fact have sustained neurological deficits that are not detected using standard clinical assessments.
Lauren Sergio
Professor Lauren E. Sergio led the research at the School of Kinesiology & Health Science with doctoral candidate Johanna Hurtubise. It is their first study looking at asymptomatic elite-level athletes who are National Hockey League (NHL) draft prospects with a history of concussion, and it shows that even in this group there is a small amount of impairment.
The research studied the prolonged difficulty in cognitive-motor integration in 51 athletes with a history of concussion who were asymptomatic and medically cleared of concussion. Their performance was compared with 51 who have never had a concussion.
Participants in both the 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 that tested cognitive-motor integration, 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 those 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," said Sergio. "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 added that standard tests used today only look at cognitive and motor tasks as separate tasks and do not combine the two, which could explain why they 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," said Sergio. "For example, movements must be made in the context of game-related rules, spatial information regarding the locations of other players and prior knowledge of how to best accomplish a given task. 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 the current return-to-play assessments – in which thinking and moving are tested separately – do not fully capture the functional disability of a concussion and therefore future research focusing on their integration (CMI tasks) is needed.
“There is a need to better understand the underlying mechanisms and motor behavioural effects of concussion. From a practical standpoint, such an understanding would inform clinicians charged with making return-to-play decisions about the potential for increased vulnerability post-concussion.”
The study, “The effect of concussion history on cognitive-motor integration in elite hockey players,” is published in Future Science journal Concussion.