The effect of days since last concussion and number of concussions on cognitive functioning in Division I athletes

Abstract

Objective: Cognitive recovery from sports concussion may be incomplete after resolution of other symptoms. It was hypothesized that independent effects of the number of days since last concussion (Days) and total number of concussions (Number) would predict poorer cognitive functioning.

Methods and procedures: Cognition was assessed in an NCAA Division I student-athlete population (n = 87) using the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery. In a MANOVA, the five ImPACT Composite scores were dependent variables, with Group (Concussion, Unaffected) as the independent variable and prior number of concussions (Number) and days since last concussion (Days; 68–2495 days) entered as covariates.

Outcomes and results: The hypothesis that Days and Number would each independently affect cognitive functioning (as assessed by ImPACT Composite scores) was only partly supported. A significant, multivariate, main effect of Days (p = 0.01) indicated that more Days predicted better cognitive functioning overall (p = 0.01). Univariate effects emerged such that more Days specifically predicted better visual memory (p = 0.004) and faster reaction times (p = 0.02). A trend toward a Group*Days*Number three-way interaction for reaction time emerged (p = 0.06), such that smaller Number and more Days each predicted slower reaction time.

Conclusions: Cognitive recovery following sports concussion may take far longer than was previously thought, the aetiology of cognitive reductions may be very complex and the ImPACT appears to be sensitive to subtle changes in cognition across time.

• Athletes
• concussion
• memory
• neuropsychology
• sport

Acknowledgements

This research was funded by a Research Allocation Committee (RAC) Pilot Research Award from the University of New Mexico Health Sciences Center and Dr Thoma’s time was supported in part by a Center of Biomedical Research Excellence (COBRE) grant 5P20RR021938/P20GM103472.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.