So, congratulations. So, Ellen and I both review all the abstracts submitted at the meeting, and the bar to get this award is very high. So, congratulations, and we would invite you to give your talk on professional athlete performance decline during concussion, analysis of three major sports. So, congratulations. We look forward to hearing your work. Thank you. I'm Aaron Yengokon. I'm a neurosurgery resident at Vanderbilt University Medical Center. I'm going to be discussing professional athlete performance following this concussion through an analysis of three major U.S. sports. I just want to thank the scientific committee for the opportunity to give this talk, and then the Think First Foundation for the Injury Prevention Award, which is a true testament to a team effort on this project. Zero disclosures. So, this project really started with a common question from athletes when they asked, how will my performance be affected after a concussion? And really a common anecdote that we see in all levels of play where an athlete has a concussion, seemingly plays worse when they return from their missed time. Jacoby Elsberry really exemplified this last season when he missed a month with a concussion, and his performance really dropped off. As you can see, his pre-concussion performance here, post-concussion, and this subsequently led to his benching, a move that he really relates to his concussion and his decline afterwards. He still hasn't come back to play this season, due to multiple other injuries now. Anecdotes like that led to multiple investigations and investigators looking into post-concussion performance. One of the first groups to do this was Wasserman et al. In 2015, they compared concussed Major League Baseball players to players that missed similar amounts of time for bereavement or paternity issues, and they found that concussed players demonstrated worse OPS upon return. So, a single statistic, but they concluded that in a sport that requires superb hand-eye coordination and visual tracking, the performance deficits seemed to persist despite being cleared clinically per protocol. We followed their investigation with three additional investigations covering the NBA, NHL, and NFL, and we found that in all of these three sports, there's really no difference from pre-concussion performance to post-concussion. But the anecdotes continue to persist, and we're really don't understand, weren't understanding why. We weren't finding anything, but there is, you know, these anecdotes persist. So, you look really closely at the data, you kind of peel through everything, and we were seeing that maybe about 20% of athletes were having a substantial decline when we looked closely. So, we felt like there was a shift in focus needed to really think more closely about this important minority of players that were doing worse when they returned, and specifically to try and figure out who is going to decline, and can we predict it, and then can we treat them earlier? So, the objectives of this talk were to describe the occurrence of post-concussion performance decline in a sample of professional athletes, and explore possible predictors. We designed a retrospective case control study of concussions that were identified in the NFL, NHL, and NBA from 2005 to 2016 through public media reports, injury reports, and they were verified with a second source. We felt that it was imperative that we have strict inclusion-exclusion criteria, and have a very clean sample of minimal confounders when we're looking at performance. So, we only used non-recurrent concussions during the season or playoff. Players had to play consecutive games before and after their concussion, and they couldn't suffer any orthopedic injuries or illnesses in that pre-post-concussion window that may affect their performance. As you can see, we identified about 1,500 concussions across the three sports, and only included 310, but we felt this was necessary to have this clean sample. We chose the readily identifiable variables of age, BMI, years experienced, salary, games missed, and contract years left as our possible predictors, and we defined our outcomes as whether or not an athlete suffered a decline in performance, and whether or not an athlete suffered a decline in playing time. We defined cases as those players that suffered a decline in playing time, and that decline was defined as a decrease in overall performance by a half-standard deviation, which was derived from the distribution of the league's pre-concussion performance. For controls, we defined those as playing the same or better than they did pre-concussion. We used logistic regression modeling with those six variables that we defined earlier, and then our outcome, again, was binary for that. For performance metrics in the NBA, we used the player impact estimate. In the NFL, we used a slightly different metric that is subjective and based on a human rating system. This has been previously used in post-concussion performance, so that's why we chose that. In the NHL, there is no real holistic measure of performance that yet existed, so we used our experience to create the NHL composite score, which we felt was a good measure of holistic performance at the NHL level. For our results, our kind of raw results here, looking by league, each of these pie charts shaded in red is the percentage of athletes that suffered a decline, as we defined. So a non-trivial percentage in each league. Overall, it's 28.5%. In terms of playing time, less athletes had a decline in playing time, but still somewhat substantial, 18.3%. When we did a logistic regression, we found that none of the six variables really predicted who was going to decline, so more work to be done there. In terms of playing time, it was clear that players that missed more games with their injury were more likely to have a loose playing time when they returned, specifically 38% more likely. So what was going on here? Players were coming back, cleared for their protocols in all the leagues, but were having declines in performance. And the answer really may be in something called dual task paradigm testing, which is a measure, a way of detecting neuromuscular control deficits. And the dual task paradigm test is essentially something like navigating an obstacle course while performing arithmetic questions or answering trivia questions, where you're combining cognitive and physical tests all into one, which is really more similar than our conventional concussion testing, more similar to playing a professional sport where you have to be thinking and performing at the same time. The, Hal et al. recently did a very nice review of all of this and they found that across multiple levels of play that these dual task paradigm deficits exist, despite concussion clearance. And they actually use this as, they propose that this may be a reason that we see orthopedic injuries at a higher rate, maybe, following concussion, that neuromuscular control deficits are lingering. And so if you think about it, neuromuscular control deficits are leading to orthopedic injuries. At the professional level, any amount of deficit in neuromuscular control is going to be, is going to come out as a performance deficit. So it may be one and the same explanation. And just to note, we excluded a number of players for having orthopedic injuries immediately after their concussion return. So that may be also an underestimate overall of the performance decline. So in conclusion, nearly 30% of NBA, NFL, NHL players may play worse upon return. They're more likely to lose playing time if they miss more games. These persistent difficulties with neuromuscular control may be the reason why we are clearing players and they come back and are suffering performance deficits. And then it's key to counsel and set expectations with these athletes to limit the psychological burden of playing worse when they return, because that can exacerbate performance deficits. Thank you.

professional athlete performance decline

concussions

predictors of performance decline

neuromuscular control deficits

managing expectations