Aberrant default mode network in amnestic mild cognitive impairment: a meta-analysis of independent component analysis studies

Abstract

Independent component analysis (ICA) is one of the most popular and valid methods to investigate the default mode network (DMN), an intrinsic network which attracts particular attention in amnestic mild cognitive impairment (aMCI). However, previous studies present inconsistent results regarding the topographical organization of the DMN in aMCI. Therefore, we conducted a quantitative, voxel-wise meta-analysis of resting-state ICA studies using Seed-based d Mapping to establish the most consistent pattern of DMN functional connectivity alterations in aMCI. Twenty studies, comprising 23 independent datasets involving 535 patients and 586 healthy controls, met the inclusion criteria. Patients with aMCI exhibited reliably lower DMN functional connectivity than the healthy controls in the bilateral precuneus/posterior cingulate cortices and medial temporal lobes, which are implicated in episodic memory deficits. Moreover, an exploratory meta-regression analysis revealed that greater severity of global cognitive impairment in the patient groups was associated with stronger functional connectivity in the bilateral medial frontal cortices (including the anterior cingulate cortices), left angular gyrus, and right temporal pole extending to the middle temporal gyrus, likely reflecting a compensatory mechanism for maintaining cognitive efficiency. This meta-analysis identifies a consistent pattern of aberrant DMN functional connectivity in aMCI, which facilitates understanding of the neurobiological substrates of this disease.

Alterations of brain local functional connectivity in amnestic mild cognitive impairment

“…These regions of ReHo alterations are critical hubs of the DMN [ 33 ]. The DMN, which is implicated in self-referential and memory processing, is the most studied brain cognitive network in aMCI and AD because it is preferentially susceptible to neurodegeneration and involves early in the AD pathophysiology [ 33 , 34 ]. Convergent evidence suggests that remote functional connectivity in the DMN in AD and aMCI is reorganized, which correlates with cognitive impairments [ 33 – 35 ].…”

A Connectomic Atlas of the Human Cerebrum—Chapter 8: The Posterior Cingulate Cortex, Medial Parietal Lobe, and Parieto-Occipital Sulcus

“…Neuroimaging research has changed this view substantially, as these areas include the posterior cingulate cortices, which have been linked to the DMN, 1,2 a large scale, restingstate network, whose dysfunction has been linked to numerous brain diseases. [12][13][14][15][16][17] Furthermore, graph theoretical analyses have suggested that the PCC areas are among the highest functionally connected clusters of brain regions in the cerebrum. 18 Our data support this view, as the functional connectivity maps of some of these areas involve a large number of spatially and functionally OPERATIVE NEUROSURGERY…”

Altered intrinsic brain activity and regional cerebral blood flow in patients with chronic neck and shoulder pain

“…The precuneus, cingulate gyrus, and middle temporal gyrus are parts of the default mode network (DMN) [26]. The DMN is usually active during rest and is suspended or weakened when engaged with the external environment [27,28]. The DMN is generally the primary network affected by chronic pain [29].…”