Superficial white matter as a novel substrate of age-related cognitive decline

Neurobiol Aging. 2015 Jun;36(6):2094-106. doi: 10.1016/j.neurobiolaging.2015.02.022. Epub 2015 Feb 27.

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.

Keywords: Cognitive-aging; Diffusion tensor imaging; Superficial white matter.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Aging / pathology*
  • Aging / psychology*
  • Anisotropy
  • Cognition / physiology*
  • Cognition Disorders / pathology*
  • Cognition Disorders / physiopathology
  • Diffusion Magnetic Resonance Imaging
  • Diffusion Tensor Imaging*
  • Female
  • Humans
  • Male
  • Middle Aged
  • White Matter / pathology*
  • White Matter / physiology
  • Young Adult