title: Superficial white matter as a novel substrate of age-related cognitive decline.
abstract: Studies of diffusion tensor imaging have focused mainly on the role of deep white matter tract microstructural abnormalities associated with aging and age-related cognitive decline. However, the potential role of superficial white matter (SWM) in aging and, by extension, cognitive-aging, is less clear. Healthy individuals (n = 141; F/M: 66/75 years) across the adult lifespan (18-86 years) underwent diffusion tensor imaging and a battery of cognitive testing. SWM was assessed via a combination of probabilistic tractography and tract-based spatial statistics (TBSS). A widespread inverse relationship of fractional anisotropy (FA) values in SWM with age was observed. SWM-FA adjacent to the precentral gyri was associated with fine-motor-speed, whereas performance in visuomotor-attention/processing speed correlated with SWM-FA in all 4 lobes of the left-hemisphere and in right parieto-occipital SWM-FA (family-wise error corrected p < 0.05). Independent of deep white matter-FA, right frontal and right occipital SWM-FA-mediated age effects on motor-speed and visuomotor-attention/processing speed, respectively. Altogether, our results indicate that SWM-FA contributes uniquely to age-related cognitive performance, and should be considered as a novel biomarker of cognitive-aging.
authors.affiliation: Kimel Family Translational Imaging-Genetics Laboratory, Ontario, Canada; Research Imaging Centre, Campbell Family Mental Health Institute, Centre for Addiction and Mental Health, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Arash
authors.initials: A
authors.lastname: Nazeri
authors.affiliation: Kimel Family Translational Imaging-Genetics Laboratory, Ontario, Canada; Research Imaging Centre, Campbell Family Mental Health Institute, Centre for Addiction and Mental Health, Ontario, Canada; Cerebral Imaging Centre, Douglas Institute, Verdun, Quebec, Canada; Department of Psychiatry, McGill University, Montreal, Quebec, Canada; Department Biomedical Engineering, McGill University, Montreal, Quebec, Canada.
authors.forename: M Mallar
authors.initials: MM
authors.lastname: Chakravarty
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Geriatric Mental Health Service, Centre for Addiction and Mental Health, Ontario, Canada; Institute of Medical Science, University of Toronto, Ontario, Canada.
authors.forename: Tarek K
authors.initials: TK
authors.lastname: Rajji
authors.affiliation: Kimel Family Translational Imaging-Genetics Laboratory, Ontario, Canada; Research Imaging Centre, Campbell Family Mental Health Institute, Centre for Addiction and Mental Health, Ontario, Canada; Institute of Medical Science, University of Toronto, Ontario, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Felsky
authors.affiliation: Kimel Family Translational Imaging-Genetics Laboratory, Ontario, Canada; Research Imaging Centre, Campbell Family Mental Health Institute, Centre for Addiction and Mental Health, Ontario, Canada.
authors.forename: David J
authors.initials: DJ
authors.lastname: Rotenberg
authors.affiliation: Kimel Family Translational Imaging-Genetics Laboratory, Ontario, Canada.
authors.forename: Mikko
authors.initials: M
authors.lastname: Mason
authors.affiliation: Kimel Family Translational Imaging-Genetics Laboratory, Ontario, Canada.
authors.forename: Li N
authors.initials: LN
authors.lastname: Xu
authors.affiliation: Research Imaging Centre, Campbell Family Mental Health Institute, Centre for Addiction and Mental Health, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Department of Neurology, University of Toronto, Ontario, Canada.
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Lobaugh
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Geriatric Mental Health Service, Centre for Addiction and Mental Health, Ontario, Canada; Institute of Medical Science, University of Toronto, Ontario, Canada.
authors.forename: Benoit H
authors.initials: BH
authors.lastname: Mulsant
authors.affiliation: Kimel Family Translational Imaging-Genetics Laboratory, Ontario, Canada; Research Imaging Centre, Campbell Family Mental Health Institute, Centre for Addiction and Mental Health, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Geriatric Mental Health Service, Centre for Addiction and Mental Health, Ontario, Canada; Institute of Medical Science, University of Toronto, Ontario, Canada. Electronic address: Aristotle.Voineskos@camh.ca.
authors.forename: Aristotle N
authors.initials: AN
authors.lastname: Voineskos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000523:psychology*; D016880:Anisotropy; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000473:pathology* / Q000503:physiopathology; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D066127:White Matter / Q000473:pathology* / Q000502:physiology; D055815:Young Adult
keywords: Cognitive-aging; Diffusion tensor imaging; Superficial white matter