scholarly journals Disrupted Thalamus White Matter Anatomy and Posterior Default Mode Network Effective Connectivity in Amnestic Mild Cognitive Impairment

2017 ◽  
Vol 9 ◽  
Author(s):  
Thomas Alderson ◽  
Elizabeth Kehoe ◽  
Liam Maguire ◽  
Dervla Farrell ◽  
Brian Lawlor ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
White Matter ◽  
Default Mode Network ◽  
Effective Connectivity ◽  
Amnestic Mild Cognitive Impairment ◽  
Default Mode ◽  
White Matter Anatomy

IC-P-031: EFFECTIVE CONNECTIVITY WITHIN THE DEFAULT MODE NETWORK IN MILD COGNITIVE IMPAIRMENT AND ALZHEIMER'S DISEASE

2006 ◽  
Vol 14 (7S_Part_1) ◽  
pp. P35-P36
Author(s):  
Cole John Cook ◽  
Gyujoon Hwang ◽  
Veena A. Nair ◽  
Andrew L. Alexander ◽  
Piero G. Antuono ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Default Mode Network ◽  
Effective Connectivity ◽  
Default Mode

scholarly journals Anosognosia predicts default mode network hypometabolism and clinical progression to dementia

Neurology ◽  
2018 ◽  
Vol 90 (11) ◽  
pp. e932-e939 ◽  
Author(s):  
Joseph Therriault ◽  
Kok Pin Ng ◽  
Tharick A. Pascoal ◽  
Sulantha Mathotaarachchi ◽  
Min Su Kang ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Default Mode Network ◽  
Cingulate Cortex ◽  
Posterior Cingulate Cortex ◽  
Amnestic Mild Cognitive Impairment ◽  
Default Mode ◽  
Posterior Cingulate ◽  
Impaired Awareness

ObjectiveTo identify the pathophysiologic mechanisms and clinical significance of anosognosia for cognitive decline in mild cognitive impairment.MethodsWe stratified 468 patients with amnestic mild cognitive impairment into intact and impaired awareness groups, determined by the discrepancy between the patient and the informant score on the Everyday Cognition questionnaire. Voxel-based linear regression models evaluated the associations between self-awareness status and baseline β-amyloid load, measured by [18F]florbetapir, and the relationships between awareness status and regional brain glucose metabolism measured by [18F]fluorodeoxyglucose at baseline and at 24-month follow-up. Multivariate logistic regression tested the association of awareness status with conversion from amnestic mild cognitive impairment to dementia.ResultsWe found that participants with impaired awareness had lower [18F]fluorodeoxyglucose uptake and increased [18F]florbetapir uptake in the posterior cingulate cortex at baseline. In addition, impaired awareness in mild cognitive impairment predicted [18F]fluorodeoxyglucose hypometabolism in the posterior cingulate cortex, left basal forebrain, bilateral medial temporal lobes, and right lateral temporal lobe over 24 months. Furthermore, participants with impaired awareness had a nearly 3-fold increase in likelihood of conversion to dementia within a 2-year time frame.ConclusionsOur results suggest that anosognosia is linked to Alzheimer disease pathophysiology in vulnerable structures, and predicts subsequent hypometabolism in the default mode network, accompanied by an increased risk of progression to dementia. This highlights the importance of assessing awareness of cognitive decline in the clinical evaluation and management of individuals with amnestic mild cognitive impairment.

scholarly journals Amnestic Mild Cognitive Impairment: Topological Reorganization of the Default-Mode Network

Radiology ◽  
2013 ◽  
Vol 268 (2) ◽  
pp. 501-514 ◽  
Author(s):  
Liang Wang ◽  
He Li ◽  
Ying Liang ◽  
Junying Zhang ◽  
Xin Li ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Default Mode Network ◽  
Amnestic Mild Cognitive Impairment ◽  
Default Mode

Altered intrinsic default mode network functional connectivity in patients with remitted geriatric depression and amnestic mild cognitive impairment

2021 ◽  
pp. 1-12
Author(s):  
Chengbin Guan ◽  
Nousayhah Amdanee ◽  
Wenxiang Liao ◽  
Chao Zhou ◽  
Xin Wu ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Posterior Cingulate Cortex ◽  
Amnestic Mild Cognitive Impairment ◽  
Geriatric Depression ◽  
Cross Sectional ◽  
Default Mode ◽  
Increased Risk

ABSTRACT Objectives: Patients with geriatric depression exhibit a spectrum of symptoms ranging from mild to severe cognitive impairment which could potentially lead to the development of Alzheimer’s disease (AD). The aim of the study is to assess the alterations of the default mode network (DMN) in remitted geriatric depression (RGD) patients and whether it could serve as an underlying neuropathological mechanism associated with the risk of progression of AD. Design: Cross-sectional study. Participants: A total of 154 participants, comprising 66 RGD subjects (which included 27 patients with comorbid amnestic mild cognitive impairment [aMCI] and 39 without aMCI [RGD]), 45 aMCI subjects without a history of depression (aMCI), and 43 matched healthy comparisons (HC), were recruited. Measurements: All participants completed neuropsychological tests and underwent resting-state functional magnetic resonance imaging (fMRI). Posterior cingulate cortex (PCC)-seeded DMN functional connectivity (FC) along with cognitive function were compared among the four groups, and correlation analyses were conducted. Results: In contrast to HC, RGD, aMCI, and RGD-aMCI subjects showed significant impairment across all domains of cognitive functions except for attention. Furthermore, compared with HC, there was a similar and significant decrease in PCC-seed FC in the bilateral medial superior frontal gyrus (M-SFG) in the RGD, aMCI, and RGD-aMCI groups. Conclusions: The aberrations in rsFC of the DMN were associated with cognitive deficits in RGD patients and might potentially reflect an underlying neuropathological mechanism for the increased risk of developing AD. Therefore, altered connectivity in the DMN could serve as a potential neural marker for the conversion of geriatric depression to AD.

Altered Effective Connectivity of the Default Mode Network in Resting-State Amnestic Type Mild Cognitive Impairment

2013 ◽  
Vol 19 (4) ◽  
pp. 400-409 ◽  
Author(s):  
Hao Yan ◽  
Yumei Zhang ◽  
Hongyan Chen ◽  
Yonghui Wang ◽  
Yijun Liu
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Default Mode Network ◽  
Effective Connectivity ◽  
Verbal Learning ◽  
Posterior Cingulate Cortex ◽  
Middle Temporal Gyrus ◽  
Causality Analysis ◽  
Default Mode ◽  
Auditory Verbal Learning

AbstractAmnestic mild cognitive impairment (aMCI) is the transitional, heterogeneous continuum from normal elderly to Alzheimer's disease (AD). Previous studies have shown that brain functional activity in the default mode network (DMN) is impaired in aMCI patients with saliently cognitive and memory decline. However, the effective connectivity among the spatially isolated, but functionally related areas within the DMN in aMCI patients remains largely unknown. The present study examined dysfunctional connectivity of the DMN by combining an independent component analysis (ICA) approach with multivariate Granger causality analysis (mGCA) in 18 aMCI patients and 18 age-matched cognitively normal elderly. Results from mGCA showed decreased effective connectivity occurred among the middle temporal gyrus (MTG), hippocampus (HC) and fusiform gyrus (FG), as well as between the precuneus/posterior cingulate cortex (PreCN/PCC) and HC in patients with aMCI. Such an impaired connectivity was also correlated with patients’ cognitive performance of the auditory verbal learning. Moreover, enhanced effective connectivity within frontal cortex emerged, which may maintain memory functions after attenuated connections within DMN activity. These findings may elucidate the dysfunctional processes in brain networks of aMCI patients, highlighting the importance of connectivity changes in the pathophysiology of aMCI. (JINS, 2013, 19, 1–10)

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