Repository logo
 

Altered structural connectivity networks in dementia with lewy bodies

Published version
Peer-reviewed

Change log

Authors

Mak, Elijah 
Surendranathan, Ajenthan 
Rittman, Timothy 
Rowe, James B. 

Abstract

Abstract: The impairment of large-scale brain networks has been observed in dementia with Lewy bodies (DLB) using functional connectivity, but the potential for an analogous effect on structural covariance patterns has not been determined. Twenty-four probable DLB subjects (mean age 74.3 ± 6.7 years, 16.7% female) and 23 similarly aged Controls were included. All participants underwent 3T MRI imaging with high-resolution T1-weighted magnetization-prepared rapid gradient echo (MPRAGE) sequence. Graph theoretical analyses were performed using variation in regional cortical thickness to construct a structural association matrix with pairwise Pearson correlations. Global and nodal graph parameters were computed to assess between-group differences and community structure was studied in order to quantify large-scale brain networks in both groups. In comparison to Controls, DLB subjects had decreased global efficiency, clustering, modularity and small-worldness of structural networks (all p < 0.05). Nodal measures showed that DLB subjects also had decreased clustering in bilateral temporal regions and decreased closeness centrality in extensive areas including right middle frontal, left cingulate and bilateral occipital lobe (all false-discovery rate (FDR)-corrected q < 0.05). Whereas four distinct modules could be clearly identified in Controls, DLB showed extensively disorganized modules, including default-mode network and dorsal attentional network. Our results suggest a marked impairment in large-scale brain structural networks in DLB, mirroring functional connectivity networks disruption.

Description

Keywords

Original Research, Dementia, Graph theory, Brain network, Cortical thickness, MRI

Journal Title

Brain Imaging and Behavior

Conference Name

Journal ISSN

1931-7557
1931-7565

Volume Title

15

Publisher

Springer US
Sponsorship
National Institute for Health Research (RG64474)
Wellcome Trust (103838)
Medical Research Foundation (MC-A060-5PQ30)