Connectivity network measures predict volumetric atrophy in mild cognitive impairment

Neurobiol Aging. 2015 Jan;36 Suppl 1(0 1):S113-20. doi: 10.1016/j.neurobiolaging.2014.04.038. Epub 2014 Aug 30.

Abstract

Alzheimer's disease (AD) is characterized by cortical atrophy and disrupted anatomic connectivity, and leads to abnormal interactions between neural systems. Diffusion-weighted imaging (DWI) and graph theory can be used to evaluate major brain networks and detect signs of a breakdown in network connectivity. In a longitudinal study using both DWI and standard magnetic resonance imaging (MRI), we assessed baseline white-matter connectivity patterns in 30 subjects with mild cognitive impairment (MCI, mean age 71.8 ± 7.5 years, 18 males and 12 females) from the Alzheimer's Disease Neuroimaging Initiative. Using both standard MRI-based cortical parcellations and whole-brain tractography, we computed baseline connectivity maps from which we calculated global "small-world" architecture measures, including mean clustering coefficient and characteristic path length. We evaluated whether these baseline network measures predicted future volumetric brain atrophy in MCI subjects, who are at risk for developing AD, as determined by 3-dimensional Jacobian "expansion factor maps" between baseline and 6-month follow-up anatomic scans. This study suggests that DWI-based network measures may be a novel predictor of AD progression.

Keywords: ADNI; Brain networks; Connectivity; DTI; Graph theory; Small worldness; TBM; Tractography; White matter.

Publication types

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

MeSH terms

  • Aged
  • Alzheimer Disease
  • Atrophy
  • Cognitive Dysfunction / pathology*
  • Cognitive Dysfunction / physiopathology*
  • Diffusion Magnetic Resonance Imaging / methods*
  • Disease Progression
  • Female
  • Forecasting
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Nerve Net / pathology
  • Nerve Net / physiopathology
  • Neural Conduction
  • Neuroimaging / methods*
  • White Matter / pathology*
  • White Matter / physiopathology*