An 18-Year Study of Changes in Neurocognitive Function and Associations with Repetitive Head Trauma among Former Collegiate American Football Players: A Case Series

Objectives: To assess changes in neurocognitive test scores among former collegiate American football players over 18 years and examine associations with head trauma history. Methods: Former collegiate American football players (n = 31; aged = 38.4 +/- 1.3 years) self-reported their concussion history and repetitive head impact exposure (Head Impact Exposure Estimate). Neurocognitive testing was conducted at two time-points (during college [T1] and 18-year follow-up [T2]) via Hopkins Verbal Learning Test-Revised Immediate and Delayed Recall; Verbal fluency; Symbol Digit Modalities Test; and Trail-Making Test-B. Raw score changes were calculated, with accompanying Cohen's d effect sizes and coefficients of variation. Repeated-measures analyses of covariance models were fit to examine changes in test performance. Multivariable linear regression models tested associations of sport-related concussion history and repetitive head impact exposure with change scores. Results: No significant changes in cognitive test performance were observed (ps >= .06). Individual-level changes exhibited high variability (coefficients of variation >= 244%), and group-level effects were small to medium (d <= 0.41). Neither sport-related concussion history nor repetitive head impacts were related to change scores (ps > .05). Conclusions: Group-level test scores did not change over 18 years among former collegiate football players now in midlife, though individual-level variability was high. Sport-related concussion and head impact exposure estimates were not related to change. Longitudinal studies are essential to understand cognitive trajectories of former football players and factors influencing those trajectories.