Open AccessAltered default mode network connectivity in alzheimer's disease—A resting functional MRI and bayesian network study
Author(s) -
Wu Xia,
Li Rui,
Fleisher Adam S.,
Reiman Eric M.,
Guan Xiaoting,
Zhang Yumei,
Chen Kewei,
Yao Li
Publication year - 2011
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.21153
Subject(s) - default mode network , neuroscience , resting state fmri , posterior cingulate , functional magnetic resonance imaging , prefrontal cortex , hippocampal formation , psychology , functional connectivity , hippocampus , posterior parietal cortex , cortex (anatomy) , cognition
A number of functional magnetic resonance imaging (fMRI) studies reported the existence of default mode network (DMN) and its disruption due to the presence of a disease such as Alzheimer's disease (AD). In this investigation, first, we used the independent component analysis (ICA) technique to confirm the DMN difference between patients with AD and normal control (NC) reported in previous studies. Consistent with the previous studies, the decreased resting‐state functional connectivity of DMN in AD was identified in posterior cingulated cortex (PCC), medial prefrontal cortex (MPFC), inferior parietal cortex (IPC), inferior temporal cortex (ITC), and hippocampus (HC). Moreover, we introduced Bayesian network (BN) to study the effective connectivity of DMN and the difference between AD and NC. When compared the DMN effective connectivity in AD with the one in NC using a nonparametric random permutation test, we found that connections from left HC to left IPC, left ITC to right HC, right HC to left IPC, to MPFC and to PCC were all lost. In addition, in AD group, the connection directions between right HC and left HC, between left HC and left ITC, and between right IPC and right ITC were opposite to those in NC group. The connections of right HC to other regions, except left HC, within the BN were all statistically in‐distinguishable from 0, suggesting an increased right hippocampal pathological and functional burden in AD. The altered effective connectivity in patients with AD may reveal more characteristics of the disease and may serve as a potential biomarker. Hum Brain Mapp, 2011. © 2011 Wiley‐Liss, Inc.