Holly Carrington BA(she/her)

Exposure to repetitive head impacts in contact sports is associated with neurodegenerative disorders including chronic traumatic encephalopathy (CTE), which currently can be diagnosed only at post-mortem. American football players are at higher risk of developing CTE given their exposure to repetitive head impacts. One promising approach for diagnosing CTE in vivo is to explore known neuropathological abnormalities at post-mortem in living individuals using structural MRI.

MRI brain morphometry was evaluated in 170 male former American football players ages 45–74 years (n = 114 professional; n = 56 college) and 54 same-age unexposed asymptomatic male controls (n = 54, age range 45–74). Cortical thickness and volume of regions of interest were selected based on established CTE pathology findings and were assessed using FreeSurfer. Group differences and interactions with age and exposure factors were evaluated using a generalized least squares model. A separate logistic regression and independent multinomial model were performed to predict each traumatic encephalopathy syndrome (TES) diagnosis, core clinical features and provisional level of certainty for CTE pathology using brain regions of interest.

Former college and professional American football players (combined) showed significant cortical thickness and/or volume reductions compared to unexposed asymptomatic controls in the hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus, insula, temporal pole and superior frontal gyrus. Post hoc analyses identified group-level differences between former professional players and unexposed asymptomatic controls in the hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus, insula and superior frontal gyrus. Former college players showed significant volume reductions in the hippocampus, amygdala and superior frontal gyrus compared to the unexposed asymptomatic controls. We did not observe Age × Group interactions for brain morphometric measures. Interactions between morphometry and exposure measures were limited to a single significant positive association between the age of first exposure to organized tackle football and right insular volume. We found no significant relationship between brain morphometric measures and the TES diagnosis core clinical features and provisional level of certainty for CTE pathology outcomes.

These findings suggested that MRI morphometrics detect abnormalities in individuals with a history of repetitive head impact exposure that resemble the anatomic distribution of pathological findings from post-mortem CTE studies. The lack of findings associating MRI measures with exposure metrics (except for one significant relationship) or TES diagnosis and core clinical features suggested that brain morphometry must be complemented by other types of measures to characterize individuals with repetitive head impacts.

Keywords. neuroimaging, structural MRI, sports-related head injury, repetitive head impact, former American football players

Purpose/Objective. Brain injuries are often “invisible” injuries that can have lifelong consequences including changes in identity, functional independence, relationships, and reduced participation in daily activities. Survivors of brain injury experience stigma and challenges related to the misattribution of symptoms to other causes that are significant barriers to recovery and adjustment. Changes in policy and other large-scale interventions are cited as an underexplored, yet critical path to reducing the impact of brain injury. The present study sought to comprehensively characterize the impact of one such initiative—Brain Injury Identification Cards—among survivors to further refine the resource.

Research Method/Design. In this cross-sectional qualitative focus group study, we recruited 16 individuals with a history of brain injury via email listservs of individuals who registered for a Brain Injury Identification Card. We used rapid data analysis with a hybrid of deductive and inductive analytic strategies to identify themes within a priori domains.

Results. We extracted themes within four domains: (a) process and reasons for obtaining cards; (b) overall impressions of the cards; (c) uses of the cards; and (d) feedback and proposed changes. Participants described the process of obtaining cards as straightforward and shared wide-ranging benefits across domains, including improving survivors’ sense of safety, self-advocacy, and ability to participate in daily activities.

Conclusions/Implications. Findings highlight the utility of Brain Injury Identification Cards for improving community understanding of brain injury symptoms and how injury-related challenges may manifest in daily life.

Purpose. Our study examined the influence of hormonal contraceptives (HC) on pre-injury (baseline) ImPACT performance in female collegiate athletes.

Methods. Participants in our cross-sectional study consisted of 304 NCAA Division I female athletes who self-reported taking (HC+ [n=154]) or not taking (HC- [n=154]) HC. HC+ participants were matched to HC- participants for height, weight, sport, and position. HC+ participants had an average age of 19.0±1.33 years, height of 170.5–8.70 cm, and mass of 64.2–10.58 kg. HC- participants had an average age of 19.0±1.24 years, height of 170.3–9.19 cm, and mass of 64.2–9.75 kg. Participants completed ImPACT as part of their preseason baseline assessment. Only participants with valid ImPACT assessments were included in our analyses. Chi-squared (χ2) tests were performed to compare groups in terms of medical history variables. Independent t-tests were used to compare groups in terms of demographic variables, self-reported hours of sleep, and ImPACT (Verbal and Visual Memory, Visual Motor Speed [VMS], Reaction Time [RT], and Total Symptom Severity [TSS]) outcome scores. Analyses were performed with α=0.05.

Results. No differences were observed between groups for demographic variables, hours of sleep, or medical history variables (p<0.05). For VMS, the HC- group (42.9+5.63) scored significantly worse (t[304]=2.17, p=0.03; d=0.25; 95% CI [0.1, 2.7]) than the HC+ group (44.3+5.67). For RT, the HC- group (0.55+0.06) performed significantly slower (t[304]=-2.02, p=0.05; d=0.23; 95% CI [-0.03, -0.0003]) than the HC+ group (0.54+0.05).

Conclusion. Our results suggest HCs may influence ImPACT performance in female collegiate athletes. Clinicians must consider the role of HCs when interpreting ImPACT outcome scores.