title: Abnormal whole-brain functional connection in amnestic mild cognitive impairment patients.
abstract: Amnestic mild cognitive impairment (aMCI) patients are thought to be particularly vulnerable to convert to clinical AD where functional disconnection is a major feature of the cortical neuropathology. However, the presence and extent of whole-brain connectivity disturbances is largely unknown in aMCI patients. Twenty-six aMCI patients and eighteen matched healthy subjects were evaluated at baseline and at mean 20 months follow up. Temporal correlations between spatially distinct regions were evaluated by using longitudinal resting-state fMRI. Compared to normal aging controls, patterns of abnormal interregional correlations in widely dispersed brain areas were identified in the patients, which also changed with disease progression. These disturbances were found particularly in subcortical regions and frontal cortex. Importantly, significantly decreased negative functional connection may be specifically associated with the development of aMCI patients. This suggests a compensatory mechanism is underway where local processing deficits are offset by recruitment of more dispersed cortical regions. In addition, the presence of this increased connectivity is seen to eventually weaken with disease progression. The results suggest that patterns of whole-brain functional connection may be a useful risk marker for conversion to AD in aMCI patients.
authors.affiliation: School of Clinical Medicine, Southeast University, Nanjing 210009, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Bai
authors.forename: Wei
authors.initials: W
authors.lastname: Liao
authors.forename: David R
authors.initials: DR
authors.lastname: Watson
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Shi
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Chunxian
authors.initials: C
authors.lastname: Yue
authors.forename: Yuhuan
authors.initials: Y
authors.lastname: Teng
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.forename: Yonggui
authors.initials: Y
authors.lastname: Yuan
authors.forename: Jianping
authors.initials: J
authors.lastname: Jia
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D000544:Alzheimer Disease / Q000150:complications / Q000503:physiopathology*; D000647:Amnesia / Q000150:complications / Q000503:physiopathology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000150:complications / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000502:physiology*; D012016:Reference Values