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], Ϫ0.19), thickness (APC, Ϫ0.35), and volume (APC, Ϫ0.51) 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.

Differential tinnitus-related neuroplastic alterations of cortical thickness and surface area

“…As indicated by our analysis, CSA and CT can be partly conceived as being distinct traits, and thus their analysis provides more nuanced information than the sole computation of CV as implemented in VBM. Given this understanding, the present study concurs with a pool of recent reports which also demonstrated the genetically and phenotypically distinctiveness of CT and CSA [38,39,41,40,42,43,65,44,45,46]. It is important to mention that CV cannot be interpreted as a simple compilation of CT and CSA.…”

“…The substantial discrepancy between studies is confusing and makes the interpretation of the (sometimes conflicting) data problematic. The methodological impediments that may complicate the comparability of studies on structural neuroplasticity in tinnitus are small sample sizes, comorbid psychological problems, differences in TI's 65 age of onset and duration, that is the interval between tinnitus onset and the time point of data acquisition. Furthermore, evidence for confined "structural abnormalities specifically related to tinnitus is sparse" [33, p. 119], and this fact makes it difficult to test specific anatomical hypotheses.…”

Motion‐related artifacts in structural brain images revealed with independent estimates of in‐scanner head motion

“…We suggest that these effects may in some cases be overestimated, particularly in certain brain locations, by the inclusion of biased estimates from T1w structural scans with motion artifacts. The present work leveraged the variability in head motion and morphometry in a healthy adult sample to show that: (1) independent estimates of motion significantly predicted GM thickness (independent of age and gender), and (2) motion slightly but significantly biased thickness estimates in several regions that are often highlighted to undergo cortical thinning with increasing age [e.g., medial PFC, cingulate cortex, precuneus, IFG and anterior insula, SMG, lateral temporal cortex; Fjell et al, 2009; Lemaitre et al, 2012; Raz et al, 2005; Salat et al, 2004; Storsve et al, 2014]. …”

Auditory Cortex Characteristics in Schizophrenia: Associations With Auditory Hallucinations

“…Cortical thickness and area are determined by different processes in embryonic cortical development 26 and appear influenced by unrelated genetic mechanisms. 27 Furthermore, thickness and area show different trajectories in the normal aging brain, 28 and may be affected differently by disease processes. It is therefore of interest to investigate these 2 components independently.…”