Effect of Head Impact Exposures on Changes in Cognitive Testing.

Background: Gaining a better understanding of head impact exposures may lead to better comprehension of the possible effects of repeated impact exposures not associated with clinical concussion.

Purpose: To assess the correlation between head impacts and any differences associated with cognitive testing measurements pre- and postseason.

Study Design: Case-control study; Level of evidence, 3.

Methods: A total of 34 National Collegiate Athletic Association Division I men's lacrosse players wore lacrosse helmets instrumented with an accelerometer during the 2014 competitive season and were tested pre- and postseason with the Sport Concussion Assessment Tool (SCAT 3) and Concussion Vital Signs (CVS) computer-based neurocognitive tests. The number of head impacts >20 g and results from the 2 cognitive tests were analyzed for differences and correlation.

Results: There was no significant difference between pre- and postseason SCAT 3 scores, although a significant correlation between pre- and postseason cognitive scores on the SCAT 3 and total number of impacts sustained was noted ( r = -0.362, P = .035). Statistically significant improvements on half of the CVS testing components included visual reaction time ( P = .037, d = 0.37), reaction time ( P = .001, d = 0.65), and simple reaction time ( P = .043, d = 0.37), but no correlation with head impacts was noted.

Conclusion: This study did not find declines in SCAT 3 or CVS scores over the course of a season among athletes who sustained multiple head impacts but no clinical concussion. Thus, it could not be determined whether there was no cognitive decline among these athletes or whether there may have been subtle declines that could not be measured by the SCAT 3 or CVS.