title: Macro- and micro-structural white matter differences correlate with cognitive performance in healthy aging.
abstract: Studies have shown that white matter (WM) volumetric reductions and overall degradation occur with aging. Nonetheless little is known about the WM alterations that may underlie different cognitive status in older individuals. The main goal of the present work was to identify and characterize possible macro and microstructural WM alterations that could distinguish between older healthy individuals with contrasting cognitive profiles (i.e., "poor" vs "good" cognitive performers). Structural and diffusion magnetic resonance imaging was performed in order to quantify local WM volumes, white matter signal abnormalities (WMSA) volume (a measure of lesion burden) and diffusion tensor imaging scalar maps known to probe WM microstructure. A battery of neurocognitive/psychological tests was administered to assess the cognitive performance. Poor performers showed a higher slope for the positive association between WMSA volume and age compared to good performers. Even when controlling for WMSA volume, poor performers also evidenced lower fractional anisotropy, as well as positive associations with age with higher slopes of regression parameters in radial and axial diffusivity. Altogether results suggest that cognitive performance is related to differences in WM, with poor cognitive performers displaying signs of faster aging in WM.
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal. paulo.c.g.marques@ecsaude.uminho.pt.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal. paulo.c.g.marques@ecsaude.uminho.pt.|Clinical Academic Center - Braga, Braga, Portugal. paulo.c.g.marques@ecsaude.uminho.pt.
authors.forename: Paulo César Gonçalves
authors.initials: PC
authors.lastname: Marques
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center - Braga, Braga, Portugal.
authors.forename: José Miguel Montenegro
authors.initials: JM
authors.lastname: Soares
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center - Braga, Braga, Portugal.
authors.forename: Ricardo José da Silva
authors.initials: RJ
authors.lastname: Magalhães
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center - Braga, Braga, Portugal.
authors.forename: Nadine Correia
authors.initials: NC
authors.lastname: Santos
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057, Braga, Portugal.|ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.|Clinical Academic Center - Braga, Braga, Portugal.
authors.forename: Nuno Jorge Carvalho
authors.initials: NJ
authors.lastname: Sousa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000523:psychology*; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D016000:Cluster Analysis; D003071:Cognition; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D025341:Principal Component Analysis; D011581:Psychological Tests; D066127:White Matter / Q000000981:diagnostic imaging* / Q000473:pathology
keywords: Aging; Cognitive performance; Diffusion tensor imaging; Tract-based spatial statistics; White matter