title: Impairment and compensation coexist in amnestic MCI default mode network.
abstract: Mild cognitive impairment (MCI) is the transitional, heterogeneous continuum from healthy elderly to Alzheimer's disease (AD). Previous studies have shown that brain functional activity in the default mode network (DMN) is impaired in AD patients. However, altering DMN activity patterns in MCI patients remains largely unclear. The present study utilized resting-state functional magnetic resonance imaging (fMRI) and an independent component analysis (ICA) approach to investigate DMN activity in 14 amnestic MCI (aMCI) patients and 14 healthy elderly. Compared to the aMCI patients, the healthy elderly exhibited increased functional activity in the DMN regions, including the bilateral precuneus/posterior cingulate cortex, right inferior parietal lobule, and left fusiform gyrus, as well as a trend towards increased right medial temporal lobe activity. The aMCI patients exhibited increased activity in the left prefrontal cortex, inferior parietal lobule, and middle temporal gyrus compared to the healthy elderly. Increased frontal-parietal activity may indicate compensatory processes in the aMCI patients. These findings suggest that abnormal DMN activity could be useful as an imaging-based biomarker for the diagnosis and monitoring of aMCI patients.
authors.affiliation: Department of Radiology, Xuanwu Hospital of Capital University of Medical Sciences, Beijing 100053, PR China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Qi
authors.forename: Xia
authors.initials: X
authors.lastname: Wu
authors.forename: Zhiqun
authors.initials: Z
authors.lastname: Wang
authors.forename: Nang
authors.initials: N
authors.lastname: Zhang
authors.forename: Huiqing
authors.initials: H
authors.lastname: Dong
authors.forename: Li
authors.initials: L
authors.lastname: Yao
authors.forename: Kuncheng
authors.initials: K
authors.lastname: Li
mesh_terms: D000368:Aged; D000647:Amnesia / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D012146:Rest; D012815:Signal Processing, Computer-Assisted