Combinaison de l’évaluation cognitive et d’un effort physique aérobie pour évaluer la disposition au retour au jeu de l’athlète ayant subi une commotion cérébrale

Concussion is especially hard to detect because clinicians must rely on self-reported symptoms to diagnose the injury and to determine when an athlete is ready to safely return to play (RTP). To guide the latter decision, many use cognitive testing. However, several studies indicate the need to develop more refined cognitive tasks, with better psychometric properties than those currently used to assess concussion. Another option would be to perform the psychometric validation of experimental tasks frequently used in research settings. Further, a recent study suggests that physical exercise can reveal deficits that were not perceptible at rest in one in four athletes, thus indicating incomplete recovery in a significant minority of the concussed athletes. Accordingly, this dissertation aimed to develop a valid and easily accessible tool to assess the readiness of recently concussed athletes to safely return to play, as well as to assess deficits in the protracted phase of the recovery. The tool includes a standardized exercise protocol (20-min on an ergocycle at 80% theoretical maximum heart rate) and a cognitive task (color-shape switch task). In the first manuscript, we examined the construct validity and the test-retest reliability of the switch task. The results suggest that the switch task is a valid measure of executive functions that shows an adequate test-retest reliability. The results also suggest that the switch costs, which are traditionally computed to isolate the different components of executive functions, do not show as good psychometric properties as primary variables do (i.e., reaction time, accuracy, and inverse efficiency score). In the second manuscript, we measured the practice effect associated with serial administration of the switch task. The results indicate that the performance improves during the first three assessments when the task is completed every 48 hours. Also, they do not support the use of alternative versions of the task in order to eliminate the practice effect as it is still present. In the third manuscript, we determined that our tool has the requisite sensitivity for detecting cognitive deficits in recently concussed athletes who had successfully completed the RTP protocol. Specifically, our tool detected deficits in 20% of athletes when the switch task is completed at rest and in an additional 10% when it is completed post-exercise. Thus, our tool can detect deficits in up to 30% of athletes who had received their medical clearance to RTP. In the 4th manuscript, we showed that our tool can detect persistent deficits stemming from sports concussion. The post-exercise testing showed deficits in 20% of athletes, deficits that were not detected at rest. Thus, the use of an acute bout of aerobic exercise may increase the sensitivity of the cognitive testing. The results herein support the use of the switch task, before and after an acute bout of exercise of moderate intensity. Moreover, they reaffirm the necessity to change the standard for assessing sports concussion. Indeed, based on the current results, the use of valid and reliable cognitive tasks, sensitive to the effects of concussion beyond the symptomatic phase, in combination with an exercise protocol, should become the gold standard.

Keyphrases: effort physique, sports, traumatic brain injury, exertion, acute exercise, recovery, athletes, construct validity, test-retest reliability, practice effect, psychometrics, executive functions, cognitive flexibility