title: Differential longitudinal changes in cortical thickness, surface area and volume across the adult life span: regions of accelerating and decelerating change.
abstract: Human cortical thickness and surface area are genetically independent, emerge through different neurobiological events during development, and are sensitive to different clinical conditions. However, the relationship between changes in the two over time is unknown. Additionally, longitudinal studies have almost invariably been restricted to older adults, precluding the delineation of adult life span trajectories of change in cortical structure. In this longitudinal study, we investigated changes in cortical thickness, surface area, and volume after an average interval of 3.6 years in 207 well screened healthy adults aged 23-87 years. We hypothesized that the relationships among metrics are dynamic across the life span, that the primary contributor to cortical volume reductions in aging is cortical thinning, and that magnitude of change varies with age and region. Changes over time were seen in cortical area (mean annual percentage change [APC], -0.19), thickness (APC, -0.35), and volume (APC, -0.51) in most regions. Volume changes were primarily explained by changes in thickness rather than area. A negative relationship between change in thickness and surface area was found across several regions, where more thinning was associated with less decrease in area, and vice versa. Accelerating changes with increasing age was seen in temporal and occipital cortices. In contrast, decelerating changes were seen in prefrontal and anterior cingulate cortices. In conclusion, a dynamic relationship between cortical thickness and surface area changes exists throughout the adult life span. The mixture of accelerating and decelerating changes further demonstrates the importance of studying these metrics across the entire adult life span.
authors.affiliation: Research Group for Lifespan Changes in Brain and Cognition, a.b.storsve@psykologi.uio.no.
authors.forename: Andreas B
authors.initials: AB
authors.lastname: Storsve
authors.affiliation: Research Group for Lifespan Changes in Brain and Cognition, Department of Physical Medicine and Rehabilitation, Unit of Neuropsychology, Oslo University Hospital, 0424 Oslo, Norway.
authors.forename: Anders M
authors.initials: AM
authors.lastname: Fjell
authors.affiliation: Research Group for Lifespan Changes in Brain and Cognition.
authors.forename: Christian K
authors.initials: CK
authors.lastname: Tamnes
authors.affiliation: Department of Psychology, University of Oslo, 0317 Oslo, Norway, and.
authors.forename: Lars T
authors.initials: LT
authors.lastname: Westlye
authors.affiliation: Research Group for Lifespan Changes in Brain and Cognition.
authors.forename: Knut
authors.initials: K
authors.lastname: Overbye
authors.affiliation: Research Group for Lifespan Changes in Brain and Cognition.
authors.forename: Hilde W
authors.initials: HW
authors.lastname: Aasland
authors.affiliation: Research Group for Lifespan Changes in Brain and Cognition, Department of Physical Medicine and Rehabilitation, Unit of Neuropsychology, Oslo University Hospital, 0424 Oslo, Norway.
authors.forename: Kristine B
authors.initials: KB
authors.lastname: Walhovd
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D001284:Atrophy; D001830:Body Surface Area; D002540:Cerebral Cortex / Q000473:pathology* / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008136:Longevity / Q000502:physiology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D055815:Young Adult
keywords: aging; area; cortex; thickness; trajectory; volume