Memory alterations over a football season are dependent on athlete position-type and prior concussion history

Lifetime accumulation of subconcussive head trauma has been linked to neurodegenerative processes, however it is only recently that measurable alterations in brain function after short bouts of repetitive head impacts have been acknowledged. The primary aim of this study was to compare changes in memory function between American Football athletes exposed to repetitive head impacts and non-contact athletes over the course of a single collegiate athletics season, including changes driven by specific athlete position-type and medical history of previous concussion.

Collegiate Football and Track and Field athletes completed a functional memory battery, measuring spatial memory, immediate memory, concentration and delayed recall at 1-14 days prior to their athletic season, and again 1-14 days following the end of the season. Rate of change in all memory domains were calculated, and group comparisons were made between sports. Position-type (Speed and Non-Speed for Football) and concussion history were included in analyses as covariates.

Track and Field athletes performed better than Football athletes in all memory measures at both time points, and significantly better in preseason concentration (z = 2.643, p = 0.008), preseason delayed recall (z = 3.253, p = 0.001), and postseason delayed recall (z = 2.396, p = 0.017). Track and Field athletes scored significantly higher in postseason spatial memory (z = 7.691, p = 0.007). Football athletes demonstrated a significantly better rate of change in concentration than Track and Field athletes (z = -2.138, p = 0.032), which was shown via pairwise comparisons to be driven by a significant difference between Track and Field athletes and Football speed position athletes (H(z)=7.678, p = 0.022). Football athletes of non-speed positions, compared to speed positions and track and field athletes, had significant decreases in rate of change scores in delayed recall with concussion history included as a covariate (H(z = -2.355, p = 0.023).

Football athletes had lower scores overall in all memory domains compared to Track and Field athletes. Memory changes after acute exposure to repetitive head impacts may be dependent upon factors such athlete positional requirements and concussion history. These findings add to clinical understanding of how athletes may be differentially affected by repetitive head impacts.