Disrupted Topological Organization in White Matter Structural Networks in Amnestic Mild Cognitive Impairment: Relationship to Subtype

To investigate the topological alterations of whole-brain white matter structural connectivity in patients with different types of amnestic mild cognitive impairment (aMCI), including single-domain (SD) and multidomain (MD) aMCI, and to explore the relationship of such connectivity with neuropsychologic performance. This study was approved by the institutional review board of Imaging Center for Brain Research, Beijing Normal University. Written informed consent was obtained from each participant. The present study involved 38 patients with aMCI (SD aMCI, n=18; MD aMCI, n=20) and 36 age- and sex-matched healthy control subjects. White-matter connectional architecture in each participant was depicted with diffusion-weighted MR imaging and represented in terms of a connectivity matrix by using a deterministic tractography method. Graph theory-based analyses were then performed to characterize brain network properties. The global topological organization of white matter networks was significantly disrupted in patients with MD aMCI (P