Cognitive Effects of Repetitive Head Impacts in High School Age American Football Players

Background:The effects of high impact and/or repetitive head impacts (HIs) from contact sports is a rapidly growing area of concern, particularly with regards long-term health outcomes.Purpose: To examine the cognitive effects of multiple HIs from a season of play in a cohort of high school starting American football players.Study Design: Cohort Study; Level 3. Methods: A total of 24 players underwent a battery of cognitive testing prior to and after a full season of football using The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and a short-form test which is novel to this study.Throughout the season, the number and magnitude of each player's HI was monitored using a helmet accelerometer.Results: As a combined cohort, the players showed improvements on the Stroop Test and ImPACT scores for verbal memory.Players with season maximum HI of >60 gravitational forces (g-force) recalled, on average, ~1.44 fewer words on a 15-word recall test at the end of the season.The group that did not experience >60 g-force HIs, conversely, showed an average increase in word recall of 0.533 words (p-value = 0.063).Regression analysis also demonstrated a negative association between maximum HI and ImPACT verbal scores ( = -0.349;p-value=0.015).On a visual memory test, the average highest level was a level of 8.67 and average highest score of 6898.79 points achieved was 8.67 and 6898.79,respectively.Cumulative g-forces correlated with a decrease in highest level achieved of 0.4 levels ( = -0.0004;p-value=0.031)and highest score achieved 943 points ( = -0.943;p-value=0.047)for every 1,000 g-forces accrued.Conclusion: These data reinforce past studies indicating poorer verbal recall in athletes who have suffered concussions or HI >60 g-forces.Additionally, multiple smaller repetitive HIs were demonstrated to adversely affect visual memory.This study has clinical implications in future research evaluating the efficacy of protocols and devices meant to decrease cognitive decline from contact sports.