Accelerated changes in white matter microstructure during aging: a longitudinal diffusion tensor imaging study.
It is well established that human brain white matter structure changes with aging, but the timescale and spatial distribution of this change remain uncertain. Cross-sectional diffusion tensor imaging (DTI) studies indicate that, after a period of relative stability during adulthood, there is an accelerated decline in anisotropy and increase in diffusivity values during senescence; and, spatially, results have been discussed within the context of several anatomical frameworks. However, inferring trajectories of change from cross-sectional data can be challenging; and, as yet, there have been no longitudinal reports of the timescale and spatial distribution of age-related white matter change in healthy adults across the adult lifespan. In a longitudinal DTI study of 203 adults between 20 and 84 years of age, we used tract-based spatial statistics to characterize the pattern of annual change in fractional anisotropy, axial diffusivity, radial diffusivity, and mean diffusivity and examined whether there was an acceleration of change with age. We found extensive and overlapping significant annual decreases in fractional anisotropy, and increases in axial diffusivity, radial diffusivity, and mean diffusivity. Spatially, results were consistent with inferior-to-superior gradients of lesser-to-greater vulnerability. Annual change increased with age, particularly within superior regions, with age-related decline estimated to begin in the fifth decade. Charting white matter microstructural changes in healthy aging provides essential context to clinical studies, and future studies should compare age trajectories between healthy participants and at-risk populations and also explore the relationship between DTI rates of change and cognitive decline.
FMRIB Centre, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, OX3 9DU, United Kingdom, claire.sexton@ndcn.ox.ac.uk.
Claire E
CE
Sexton
Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, NO-0316 Oslo, Norway.
Kristine B
KB
Walhovd
Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, NO-0316 Oslo, Norway.
Andreas B
AB
Storsve
Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, NO-0316 Oslo, Norway.
Christian K
CK
Tamnes
K.G. Jebsen Center for Psychosis Research, Norwegian Center for Mental Disorders Research, Division of Mental Health and Addiction, Oslo University Hospital, NO-0316 Oslo, Norway, and Department of Psychology, University of Oslo, NO-0316 Oslo, Norway.
Lars T
LT
Westlye
FMRIB Centre, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, OX3 9DU, United Kingdom.
Heidi
H
Johansen-Berg
Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, NO-0316 Oslo, Norway.
Anders M
AM
Fjell
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D016880:Anisotropy; D056324:Diffusion Tensor Imaging; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D012727:Sex Characteristics; D066127:White Matter / Q000033:anatomy & histology*; D055815:Young Adult
DTI; aging; lifespan; longitudinal; white matter