Objective To assess interrelationships among neuroimaging findings with neurocognitive test performance and symptom endorsement in a cohort of retired professional (NFL) football players.

Design Prospective cohort study.

Setting Neurology clinic.

Participants Forty-five retired NFL players.

Intervention MRI scan assessment of cavum septum pellucidi, global mean score of Fractional Anisotropy (FA), and microhemorrhages.

Outcome measures Nine neuropsychological tests and multiple symptom and depression scores. Associations among the three independent neuroimaging results with these outcome measures were assessed utilising Pearson’s, Spearman’s Rank, and Point-Biserial Correlations.

Results The retirees reported an average of 6.9 (±6.2) concussions and 13.0 (±7.9) sport-related “dings” in the NFL. Assessment of cavum septum pellucidum yielded a negative finding in 10 subjects (22%), while 32 (71%) had a small, and 3 (7%) had a large one. Four (9%) of the subjects had microhemorrhages present and average FA mean was 0.459 (±0.035). Number of sport-related “dings” was correlated with an increased risk of microhemorrhages (r=0.305, p=0.042). The majority (50.8%) of the correlations obtained among the three neuroimaging parameters and the neurocognitive/symptom scores were below the threshold of a “small” effect size (r<0.10). The remaining (49.2%) correlations fell somewhere between “small” and “medium” effect sizes (0.1< r<0.3). However, all correlations were statistically non-significant.

Conclusions The current results demonstrate minimal and statistically non-significant correlations among neuroimaging, neurocognitive, and symptom scores examined in a cohort of NFL retirees. While an often-accepted paradigm, certain neuroimaging findings may not relate consistently and directly with neurocognitive test performance and clinical symptom burden.

Competing interests None.

GS Solomon receives consulting fees from the Tennessee Titans (NFL), the Nashville Predators (NHL), and the athletic departments of several universities; all fees paid to institution. In addition he is a member of the ImPACT Scientific Advisory Board and receives reimbursement for expenses to board meetings

AK Sills is a consulting physician to the Nashville Predators (uncompensated) and also serves as an unaffiliated neurotrauma consultant for the NFL

Examinations of the NFL retirees were sponsored by the National Football League (NFL) and coordinated with the NFL Players Association (NFLPA). IR Casson served as a member of the NFL MTBI Committee from 1994-2009 and as a co-chair from 2007-2009. He has done consulting for law firms and insurance companies.