A-09 Challenges in Measuring Repetitive Head Impacts, Cognition, and Eye Movements in High School Football Players

Abstract

Abstract Purpose: Assess the feasibility of measuring Repetitive Head Impacts (RHI), cognition, and eye movements across a single season of high school football. Methods: Twelve players were provided an instrumented mouthguard (3200 Hz; Prevent Biometrics, Edina, MA) to evaluate RHI. Mouthguard use was assessed by total impacts and number of games/practices. Seven players also agreed to complete cognitive (ImPACT) and custom eye-tracking (500 Hz; EyeLink II) assessments pre-, mid-, and post-season. Multiple repeated measure ANOVA’s were completed using standard composite scores for ImPACT and oculomotor metrics. Results: Fifty percent of players ever used their mouthguard, and substantial variability in total impacts (M = 86.5, SD = 98.0, Range = 7–277) and number of games/practices (M = 9.8, SD = 7.6, Range = 2–23) were observed among players who did use their mouthguard. Specific completion rates for the 3 cognitive and 3 eye-tracking assessments were 71% each, and 57% of players completed all 6 scheduled assessments. Repeated measures ANOVA indicated Visual Motor Speed (VMS) improved between assessments (p = 0.015). Post hoc analysis showed both VMS and Verbal Memory increased from pre- to mid-season (−5.30(95%CI, −10.47 to −0.12), p = 0.046), (−0.20(95%CI, −13.00 to −1.41), p = 0.024). Conclusions: Variability in mouthguard use and missing assessment rates represent practical challenges in prospectively measuring RHI and utilizing multiple longitudinal assessment methods in high school football players. Although ImPACT results should be interpreted cautiously, future research should consider the potential role of practice effects and/or intentionally poor pre-season effort to explain the increase in performance during the season. A larger sample size will increase the possibility of measuring the effect of RHI on assessment outcomes.