Introduction: Repetitive brain trauma (RBT) in American football has become a topic of recent interest. The objective of this study was to assess the interrelationships among neuroimaging findings with neurocognitive test performance and symptom endorsement in a cohort of retired professional (NFL) football players.
Methods: Magnetic resonance imaging (MRI) scans were performed in 45 retired NFL players. Three neuroimaging parameters were recorded by blinded, board-certified neuroradiologists: 1) the absence or presence of small or large cavum septum pellucidum; 2) a global mean score of Fractional Anisotropy (FA); and 3) the presence or absence of microhemorrhages,(microbleeds). The subjects underwent a battery of 9 paper and pencil neuropsychological tests (yielding 12 separate scores), a computerized neurocognitive test, and multiple (4) symptom and depression scales. The associations among the three independent neuroimaging results with these outcome measures were assessed utilizing Pearson’s, Spearman’s Rank, and Point-Biserial Correlations.
Results: Data from 45 retired NFL players (average age: 46.7 years ) were analyzed. 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 in a cohort of NFL retirees. The results indicate that in this cohort, neuroimaging findings do not relate directly to neurocognitive test performance and clinical symptom burden. While an often-accepted paradigm, associating the severity of structural brain changes to neurocognitive performance and symptom presentation after chronic RBT is complex, may involve other moderating variables, and requires further study.
Patient Care: These results will help practitioners better understand how MRI findings may or may not be related to neuropsychological and behavioral outcomes in current and retired athletes.
Learning Objectives: By the concussion of this session, participants should be able to: 1) understand the relationship between brain imaging findings and neurological outcomes in retired NFL players.