Impaired long distance functional connectivity and weighted network architecture in Alzheimer's disease

Liu, Yong, Yu, Chunshui, Zhang, Xinqing, Liu, Jieqiong, Duan, Yunyun, Alexander-Bloch, Aaron F., Liu, Bing, Jiang, Tianzi and Bullmore, Ed (2014) Impaired long distance functional connectivity and weighted network architecture in Alzheimer's disease. Cerebral Cortex, 24 6: 1422-1435. doi:10.1093/cercor/bhs410

Author Liu, Yong
Yu, Chunshui
Zhang, Xinqing
Liu, Jieqiong
Duan, Yunyun
Alexander-Bloch, Aaron F.
Liu, Bing
Jiang, Tianzi
Bullmore, Ed
Title Impaired long distance functional connectivity and weighted network architecture in Alzheimer's disease
Journal name Cerebral Cortex   Check publisher's open access policy
ISSN 1047-3211
Publication date 2014-06-01
Year available 2013
Sub-type Article (original research)
DOI 10.1093/cercor/bhs410
Open Access Status DOI
Volume 24
Issue 6
Start page 1422
End page 1435
Total pages 14
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Language eng
Abstract Alzheimer's disease (AD) is increasingly recognized as a disconnection syndrome, which leads to cognitive impairment due to the disruption of functional activity across large networks or systems of interconnected brain regions. We explored abnormal functional magnetic resonance imaging (fMRI) resting-state dynamics, functional connectivity, and weighted functional networks, in a sample of patients with severe AD (N = 18) and age-matched healthy volunteers (N = 21). We found that patients had reduced amplitude and regional homogeneity of low-frequency fMRI oscillations, and reduced the strength of functional connectivity, in several regions previously described as components of the default mode network, for example, medial posterior parietal cortex and dorsal medial prefrontal cortex. In patients with severe AD, functional connectivity was particularly attenuated between regions that were separated by a greater physical distance; and loss of long distance connectivity was associated with less efficient global and nodal network topology. This profile of functional abnormality in severe AD was consistent with the results of a comparable analysis of data on 2 additional groups of patients with mild AD (N = 17) and amnestic mild cognitive impairment (MCI; N = 18). A greater degree of cognitive impairment, measured by the mini-mental state examination across all patient groups, was correlated with greater attenuation of functional connectivity, particularly over long connection distances, for example, between anterior and posterior components of the default mode network, and greater reduction of global and nodal network efficiency. These results indicate that neurodegenerative disruption of fMRI oscillations and connectivity in AD affects long-distance connections to hub nodes, with the consequent loss of network efficiency. This profile was evident also to a lesser degree in the patients with less severe cognitive impairment, indicating that the potential of resting-state fMRI measures as biomarkers or predictors of disease progression in AD.
Keyword Alzheimer's disease
Functional connectivity
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Publlished online 11 January 2013

Document type: Journal Article
Sub-type: Article (original research)
Collections: Queensland Brain Institute Publications
Official 2014 Collection
Centre for Advanced Imaging Publications
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Citation counts: TR Web of Science Citation Count  Cited 56 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 63 times in Scopus Article | Citations
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Created: Tue, 30 Jul 2013, 22:15:59 EST by Debra McMurtrie on behalf of Queensland Brain Institute