The relationship between brain atrophy and cognitive-behavioural symptoms in retired Canadian football players with multiple concussions

Abstract

Multiple concussions, particularly in contact sports, have been associated with cognitive deficits, psychiatric impairment and neurodegenerative diseases like chronic traumatic encephalopathy. We used volumetric and deformation-based morphometric analyses to test the hypothesis that repeated concussions may be associated with smaller regional brain volumes, poorer cognitive performance and behavioural symptoms among former professional football players compared to healthy controls. This study included fifty-three retired Canadian Football League players, 25 age- and education-matched healthy controls, and controls from the Cambridge Centre for Aging and Neuroscience database for validation. Volumetric analyses revealed greater hippocampal atrophy than expected for age in former athletes with multiple concussions than controls and smaller left hippocampal volume was associated with poorer verbal memory performance in the former athletes. Deformation-based morphometry confirmed smaller bilateral hippocampal volume that was associated with poorer verbal memory performance in athletes. Repeated concussions may lead to greater regional atrophy than expected for age.

Concussion and long-term cognitive impairment among professional or elite sport-persons: a systematic review

“…Overall, 14 studies met the inclusion/exclusion criteria and were therefore included in the review22–35 (online supplementary table 3). A total of 35 studies were excluded because used a partially overlapping sample, did not include professional or elite-level athletes, were single case-reports, were based on neuropathological/brain bank series, were missing essential information on details of the cognitive assessment, there was no direct or suitably indirect comparison between concussion and cognition, cognitive assessment was measured immediately after concussion or because the full text was not available (figure 1).…”

“…Bang et al reported a case-series of five boxers 25. Nine studies compared different degrees of concussion within the same group of sportsmen (internal comparison)23 26–33; three studies also used as a comparison group another athlete population less exposed to concussion (between-sports comparison),24 27 31 with the remaining using only non-athlete controls (external comparison) 22 25 34 35…”

“…Three studies included rugby players,27 31 32 eight included American footballers,22–24 29 30 33–35 with two including ice hockey players,24 28 and two studies included boxers,25 26 one of which compared boxers with martial arts fighters26 (online supplementary table 3).…”

Longitudinal change in regional brain volumes with exposure to repetitive head impacts

“…4 Similarly, we and others have reported associations between volumes of certain brain regions and exposure to RHI as well as clinical outcomes in cross-sectional studies. 5,6 Less is known about using volumetric MRI techniques in a longitudinal manner in those exposed to RHI.…”

Cerebral Atrophy in Amyotrophic Lateral Sclerosis Parallels the Pathological Distribution of TDP43

“…3T rather than 1.5T), yielding images with better contrast. All the image processing tools used in this study have been developed and extensively validated for use in multi-center studies involving different MRI systems, and have been used in numerous such studies (Zeighami et al, 2015, Dadar et al, 2018bMisquitta et al, 2018;Dadar et al, 2019;Manera et al, 2019;Sanford et al, 2019). In addition, all analyses included center as a categorical random effect to ensure that any residual variability across centers would not bias the results.…”