title: Diffuse white matter tract abnormalities in clinically normal ageing retired athletes with a history of sports-related concussions.
abstract: Sports-related concussions have been shown to lead to persistent subclinical anomalies of the motor and cognitive systems in young asymptomatic athletes. In advancing age, these latent alterations correlate with detectable motor and cognitive function decline. Until now, the interacting effects of concussions and the normal ageing process on white matter tract integrity remain unknown. Here we used a tract-based spatial statistical method to uncover potential white matter tissue damage in 15 retired athletes with a history of concussions, free of comorbid medical conditions. We also investigated potential associations between white matter integrity and declines in cognitive and motor functions. Compared to an age- and education-matched control group of 15 retired athletes without concussions, former athletes with concussions exhibited widespread white matter anomalies along many major association, interhemispheric, and projection tracts. Group contrasts revealed decreases in fractional anisotropy, as well as increases in mean and radial diffusivity measures in the concussed group. These differences were primarily apparent in fronto-parietal networks as well as in the frontal aspect of the corpus callosum. The white matter anomalies uncovered in concussed athletes were significantly associated with a decline in episodic memory and lateral ventricle expansion. Finally, the expected association between frontal white matter integrity and motor learning found in former non-concussed athletes was absent in concussed participants. Together, these results show that advancing age in retired athletes presenting with a history of sports-related concussions is linked to diffuse white matter abnormalities that are consistent with the effects of traumatic axonal injury and exacerbated demyelination. These changes in white matter integrity might explain the cognitive and motor function declines documented in this population.
authors.affiliation: 1 Integrated Program in Neuroscience, Montreal Neurological Institute, McGill University, Montreal, Canada.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Tremblay
authors.affiliation: 2 University of Pittsburgh Medical Centre, Pittsburgh, PA, USA.
authors.forename: Luke C
authors.initials: LC
authors.lastname: Henry
authors.affiliation: 3 Hôpital du Sacré-Coeur de Montréal Research Center, Montreal, Canada.
authors.forename: Christophe
authors.initials: C
authors.lastname: Bedetti
authors.affiliation: 3 Hôpital du Sacré-Coeur de Montréal Research Center, Montreal, Canada 4 Department of Psychology, Université de Montréal, Montreal, Canada.
authors.forename: Camille
authors.initials: C
authors.lastname: Larson-Dupuis
authors.affiliation: 3 Hôpital du Sacré-Coeur de Montréal Research Center, Montreal, Canada 5 Department of Psychology, Université du Québec à Montréal, Montréal, Canada.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Gagnon
authors.affiliation: 6 McConnell Brain Imaging Centre, McGill University, Montréal, Canada 7 Montreal Neurological Institute, Montréal, Canada.
authors.forename: Alan C
authors.initials: AC
authors.lastname: Evans
authors.affiliation: 4 Department of Psychology, Université de Montréal, Montreal, Canada 8 Centre de recherche en Neuropsychologie et Cognition, Université de Montréal, Montreal, Canada.
authors.forename: Hugo
authors.initials: H
authors.lastname: Théoret
authors.affiliation: 4 Department of Psychology, Université de Montréal, Montreal, Canada 8 Centre de recherche en Neuropsychologie et Cognition, Université de Montréal, Montreal, Canada.
authors.forename: Maryse
authors.initials: M
authors.lastname: Lassonde
authors.affiliation: 3 Hôpital du Sacré-Coeur de Montréal Research Center, Montreal, Canada 9 Department of Psychology, Université du Québec à Trois-Rivières, Trois-Rivières, Canada louis.debeaumont@uqtr.ca.
authors.forename: Louis
authors.initials: L
authors.lastname: De Beaumont
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology; D056352:Athletes; D001924:Brain Concussion / Q000473:pathology* / Q000503:physiopathology; D002552:Cerebral Ventricles / Q000473:pathology; D003072:Cognition Disorders / Q000473:pathology* / Q000503:physiopathology; D056324:Diffusion Tensor Imaging / Q000295:instrumentation / Q000379:methods*; D005538:Football / Q000293:injuries*; D006688:Hockey / Q000293:injuries*; D006801:Humans; D008297:Male; D008875:Middle Aged; D066127:White Matter / Q000473:pathology* / Q000503:physiopathology
keywords: ageing; neuropsychology; sports-related concussions; white matter