Toward systems neuroscience in mild cognitive impairment and Alzheimer's disease: A meta‐analysis of 75 fMRI studies

Abstract

Most of the previous task functional magnetic resonance imaging (fMRI) studies found abnormalities in distributed brain regions in mild cognitive impairment (MCI) and Alzheimer's disease (AD), and few studies investigated the brain network dysfunction from the system level. In this meta-analysis, we aimed to examine brain network dysfunction in MCI and AD. We systematically searched task-based fMRI studies in MCI and AD published between January 1990 and January 2014. Activation likelihood estimation meta-analyses were conducted to compare the significant group differences in brain activation, the significant voxels were overlaid onto seven referenced neuronal cortical networks derived from the resting-state fMRI data of 1,000 healthy participants. Thirty-nine task-based fMRI studies (697 MCI patients and 628 healthy controls) were included in MCI-related meta-analysis while 36 task-based fMRI studies (421 AD patients and 512 healthy controls) were included in AD-related meta-analysis. The meta-analytic results revealed that MCI and AD showed abnormal regional brain activation as well as large-scale brain networks. MCI patients showed hypoactivation in default, frontoparietal, and visual networks relative to healthy controls, whereas AD-related hypoactivation mainly located in visual, default, and ventral attention networks relative to healthy controls. Both MCI-related and AD-related hyperactivation fell in frontoparietal, ventral attention, default, and somatomotor networks relative to healthy controls. MCI and AD presented different pathological while shared similar compensatory large-scale networks in fulfilling the cognitive tasks. These system-level findings are helpful to link the fundamental declines of cognitive tasks to brain networks in MCI and AD.

O3‐08‐02: Resting‐State Network Dysfunction in Alzheimer's Disease: A Systematic Review And Meta‐Analysis

“…This finding is in line with previous meta-analyses centered on the DMN [21,22], and a recent study published after we completed our analysis [23]. DMN deterioration appears robust to the choice of analytical approaches, as previous meta-analyses largely included studies measuring regional homogeneity and amplitude of low-frequency fluctuation.…”

Healing Dysfunctional Identity: Bridging Mind-Body Intervention to Brain Systems

“…For example, alexithymia was associated with apathy and companion's distress in patients with neurodegenerative diseases [77] and neurodegenerative diseases implicated FPN and DMN atrophy [78]. While MBB effects on FPN, VAN, and DMN cortical networks remain to be tested in the future, we hope our presentation of MBB as practice and the AGIR model as neuroscience-informed theory will be useful in stimulating readers to continue to search for resolutions (or dissolutions) for dysfunctional problems originating in the counter-productive embodiment of identity-grasping fallacy.…”

P2‐069: Resting‐State Abnormalities in Amnestic Mild Cognitive Impairment: A Meta‐Analysis

“…12 In addition, reduced resting-state activity was also found in the PCC, right angular gyrus, right parahippocampal gyrus and left fusiform gyrus that were not reported in the previous ALE study. 12 Importantly, the absence of reduced restingstate activity in these regions in the previous ALE study included a heterogeneous sample of MCI patients (that is, aMCI and svMCI), suggesting that the two subtypes of MCI may possess distinct pathophysiological characteristics. In fact, increases in restingstate activity in the PCC have been reported in patients with svMCI.…”

“…12 Indeed, a previous study that reported a similar resting-state hypoactivity in the medial frontal gyrus was conducted in svMCI patients compared with controls, 13 and the study was also included in the previous ALE meta-analysis. We did not, however, observe any significant hypoactivity in these regions in aMCI.…”

“…12 Hence, the present analysis aimed to comprehensively review the abnormalities in resting-state activity in aMCI patients specifically, who have a high risk of conversion to AD, using activation likelihood estimation (ALE). An updated ALE analysis focusing on aMCI patients could provide a reasonable means to resolving discrepancies in previously reported findings.…”