Alterations of brain local functional connectivity in amnestic mild cognitive impairment

Abstract

BackgroundResting-state functional magnetic resonance imaging studies using a regional homogeneity (ReHo) method have reported that amnestic mild cognitive impairment (aMCI) was associated with abnormalities in local functional connectivity. However, their results were not conclusive.MethodsSeed-based d Mapping was used to conduct a coordinate-based meta-analysis to identify consistent ReHo alterations in aMCI.ResultsWe identified 10 studies with 11 datasets suitable for inclusion, including 378 patients with aMCI and 435 healthy controls. This meta-analysis identified significant ReHo alterations in patients with aMCI relative to healthy controls, mainly within the default mode network (DMN) (bilateral posterior cingulate cortex [PCC], right angular gyrus, bilateral middle temporal gyri, and left parahippocampal gyrus/hippocampus), executive control network (right superior parietal lobule and dorsolateral prefrontal cortex), visual network (right lingual gyrus and left middle occipital gyrus), and sensorimotor network (right paracentral lobule/supplementary motor area, right postcentral gyrus and left posterior insula). Significant heterogeneity of ReHo alterations in the bilateral PCC, left parahippocampal gyrus/hippocampus, and right superior parietal lobule/angular gyrus was observed. Exploratory meta-regression analyses indicated that general cognitive function, gender distribution, age, and education level partially contributed to this heterogeneity.ConclusionsThis study provides provisional evidence that aMCI is associated with abnormal ReHo within the DMN, executive control network, visual network, and sensorimotor network. These local functional connectivity alterations suggest coexistence of functional deficits and compensation in these networks. These findings contribute to the modeling of brain functional connectomes and to a better understanding of the neural substrates of aMCI. Confounding factors merit much attention and warrant future investigations.Electronic supplementary materialThe online version of this article (10.1186/s40035-018-0134-8) contains supplementary material, which is available to authorized users.

Differing Spontaneous Brain Activity in Healthy Adults with Two Different Body Constitutions: A Resting-State Functional Magnetic Resonance Imaging Study

“…Additionally, neural coherence decreased in the postcentral gyrus of BCQ-D individuals, which was negatively correlated to the physiological subdomain of the WHOQOL-BREF. These results are consistent with previous findings of ALFF of increasing ReHo in the postcentral gyrus may relate to healthy adults with the functional disorder of IBS with depression or MCI [36,37], and decreased ReHo in the postcentral gyrus may associate with better physiological function in our study of BCQ-D group. This suggests that increased local coherence in the cerebellum/lingual gyrus and decreased ReHo in the postcentral gyrus may contribute to functional integration between cerebellar-cortical circuits and somatosensory network to maintain daily physiological activity homeostatically in the BCQ-D group.…”

“…Previous fMRI studies on the functional disorder or pre-disease state have reported increased ReHo activity in the postcentral gyrus associated with irritable bowel syndrome (IBS) with depression and mild cognitive impairment (MCI) respectively [36,37]. Moreover, experimentally induced low back pain in healthy subjects showed decreased ReHo in the primary somatosensory cortex after painful stimulation [38].…”

Structural and Functional Hippocampal Changes in Subjective Cognitive Decline From the Community

“…The alterations of pathology and structure in the sensorimotor cortices was least observed in aMCI and they are found to be preserved in AD relatively (Pearson et al, 1985;Frisoni et al, 2009). Accordingly, the increased ReHo found in the sensorimotor network might be interpreted as compensatory mechanism to the functional disruptions of other brain networks (Zhen et al, 2018). However, study with the result of functional abnormality in aMCI (Zhao et al, 2014) provided support to the assumption that part of the motor areas might have cognitive functions (Hanakawa et al, 2002).…”

Altered Regional Cerebral Blood Flow and Brain Function Across the Alzheimer's Disease Spectrum: A Potential Biomarker

“…The study identified multiple areas of the brain with decreased activity and disrupted FC (Liu et al, 2008 ; Han et al, 2012 ; Zhang et al, 2012 ; Pan et al, 2017 ; Min et al, 2019 ). Additionally, two recent meta-analyses demonstrated that the decreased ALFF and ReHo in patients with MCI were primarily located in the BPCC/PCUN, bilateral frontal, left occipitotemporal cortex, and parietal lobule compared to HC (Pan et al, 2017 ; Zhen et al, 2018 ). In the present study, the findings showed that the altered regions were mainly located in the posterior areas of the brain, including the PCC/PCUN, LMTG, IPL, SOG, FFG, and LING.…”