White matter integrity disruption in the pre‐dementia stages of Alzheimer's disease: from subjective memory impairment to amnestic mild cognitive impairment

2019 ◽  
Vol 26 (5) ◽  
pp. 800-807 ◽  
Author(s):  
W. Shao ◽  
X. Li ◽  
J. Zhang ◽  
C. Yang ◽  
W. Tao ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
White Matter ◽  
Memory Impairment ◽  
Amnestic Mild Cognitive Impairment ◽  
White Matter Integrity ◽  
Subjective Memory ◽  
Subjective Memory Impairment

Disrupted White Matter Networks from Subjective Memory Impairment to Amnestic Mild Cognitive Impairment

2021 ◽  
Vol 18 (1) ◽  
pp. 35-44
Author(s):  
Wen Shao ◽  
Xuwen He ◽  
Xin Li ◽  
Wuhai Tao ◽  
Junying Zhang ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
White Matter ◽  
Memory Impairment ◽  
Diffusion Tensor ◽  
Amnestic Mild Cognitive Impairment ◽  
Subjective Memory ◽  
Subjective Memory Impairment ◽  
Parietal Lobes ◽  
Network Disruptions

Background and Objective: Subjective memory impairment (SMI) is a preclinical stage prior to amnestic mild cognitive impairment (aMCI) along with the Alzheimer’s disease (AD) continuum. We hypothesized that SMI patients had white matter (WM) network disruptions similar to those in aMCI patients. Methods: We used diffusion-tensor magnetic resonance imaging and graph theory to construct, analyze, and compare the WM networks among 20 normal controls (NC), 20 SMI patients, and 20 aMCI patients. Results: Compared with the NC group, the SMI group had significantly decreased global and local efficiency and an increased shortest path length. Moreover, similar to the aMCI group, the SMI group had lower nodal efficiency in regions located in the frontal and parietal lobes, limbic systems, and caudate nucleus compared to that of the NC group. Conclusion: Similar to aMCI patient, SMI patients exhibited WM network disruptions, and detection of these disruptions could facilitate the early detection of SMI.

The Anterior-posterior Functional Connectivity Disconnection in the Elderly with Subjective Memory Impairment and Amnestic Mild Cognitive Impairment

2020 ◽  
Vol 17 (4) ◽  
pp. 373-381
Author(s):  
Wuhai Tao ◽  
Jinping Sun ◽  
Xin Li ◽  
Wen Shao ◽  
Jing Pei ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Memory Impairment ◽  
Amnestic Mild Cognitive Impairment ◽  
Magnetic Resonance Imaging Scan ◽  
Subjective Memory ◽  
Long Distance ◽  
Whole Brain ◽  
Subjective Memory Impairment

Background: Subjective Memory Impairment (SMI) may tremendously increase the risk of Alzheimer’s Disease (AD). The full understanding of the neuromechanism of SMI will shed light on the early intervention of AD. Methods: In the current study, 23 Healthy Controls (HC), 22 SMI subjects and 24 amnestic Mild Cognitive Impairment (aMCI) subjects underwent the comprehensive neuropsychological assessment and the resting-state functional magnetic resonance imaging scan. The difference in the connectivity of the Default Mode Network (DMN) and Functional Connectivity (FC) from the Region of Interest (ROI) to the whole brain were compared, respectively. Results: The results showed that HC and SMI subjects had significantly higher connectivity in the region of the precuneus area compared to aMCI subjects. However, from this region to the whole brain, SMI and aMCI subjects had significant FC decrease in the right anterior cingulum, left superior frontal and left medial superior frontal gyrus compared to HC. In addition, this FC change was significantly correlated with the cognitive function decline in participants. Conclusion: Our study indicated that SMI subjects had relatively intact DMN connectivity but impaired FC between the anterior and posterior brain. The findings suggest that long-distance FC is more vulnerable than the short ones in the people with SMI.

scholarly journals Amnestic mild cognitive impairment and incident dementia and Alzheimer's disease in geriatric depression

2014 ◽  
Vol 26 (12) ◽  
pp. 2029-2036 ◽  
Author(s):  
David C Steffens ◽  
Douglas R McQuoid ◽  
Guy G Potter
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Memory Impairment ◽  
Laboratory Data ◽  
Amnestic Mild Cognitive Impairment ◽  
Cognitive Diagnosis ◽  
Geriatric Depression ◽  
Incident Dementia

ABSTRACTBackground:Memory impairment in geriatric depression is understudied, but may identify individuals at risk for development of dementia and Alzheimer's disease (AD). Using a neuropsychologically based definition of amnestic mild cognitive impairment (aMCI) in patients with geriatric depression, we hypothesized that patients with aMCI, compared with those without it, would have increased incidence of both dementia and AD.Methods:Participants were aged 60 years and older and consisted of depressed participants and non-depressed volunteer controls. The depressed cohort met criteria for unipolar major depression. All participants were free of dementia and other neurological illness at baseline. At study entry, participants were administered a standardized clinical interview, a battery of neurocognitive tests, and provided a blood sample for determination of apolipoprotein E genotype. A cognitive diagnosis was assigned by a panel of experts who convened annually and reviewed available clinical, neuropsychological and laboratory data to achieve a consensus cognitive diagnosis to determine a consensus diagnosis. Survival analysis examined the association between aMCI and later dementia (all-cause) and AD.Results:Among 295 depressed individuals, 63 (21.36%) met criteria for aMCI. Among 161 non-depressed controls, four (2.48%) met aMCI criteria. Participants were followed for 6.28 years on average. Forty-three individuals developed dementia, including 40 (13.6%) depressed and three (1.9%) control participants. Both aMCI and age were associated with incident dementia and AD.Conclusions:The presence of aMCI is a poor prognostic sign among patients with geriatric depression. Clinicians should carefully screen elderly depressed adults for memory impairment.

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