Potential Role of Diffusion Tensor MRI in the Differential Diagnosis of Mild Cognitive Impairment and Alzheimer's Disease

Introduction: Alzheimer’s disease (AD) is the most frequently occurring neurodegenerative disease; however, little work has been conducted examining biomarkers of AD among Mexican Americans. Here, we examined diffusion tensor MRI marker profiles for detecting mild cognitive impairment (MCI) and dementia in a multi-ethnic cohort. Methods: 3T MRI measures of fractional anisotropy (FA) were examined among 1,636 participants of the ongoing community-based Health & Aging Brain among Latino Elders (HABLE) community-based study (Mexican American n = 851; non-Hispanic white n = 785). Results: The FA profile was highly accurate in detecting both MCI (area under the receiver operating characteristic curve [AUC] = 0.99) and dementia (AUC = 0.98). However, the FA profile varied significantly not only between diagnostic groups but also between Mexican Americans and non-Hispanic whites. Conclusion: Findings suggest that diffusion tensor imaging markers may have a role in the neurodiagnostic process for detecting MCI and dementia among diverse populations.

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Group-level progressive alterations in brain connectivity patterns revealed by diffusion-tensor brain networks across severity stages in Alzheimer’s disease

10.1101/105270 ◽

2017 ◽

Author(s):

J. Rasero ◽

C. Alonso-Montes ◽

I. Diez ◽

L. Olabarrieta-Landa ◽

L. Remaki ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Disease Severity ◽

Diffusion Tensor ◽

Brain Networks ◽

Stage Ii ◽

Group Level ◽

The Brain

AbstractAlzheimer’s disease (AD) is a chronically progressive neurodegenerative disease highly correlated to aging. Whether AD originates by targeting a localized brain area and propagates to the rest of the brain across disease-severity progression is a question with an unknown answer. Here, we aim to provide an answer to this question at the group-level by looking at differences in diffusion-tensor brain networks. In particular, making use of data from Alzheimer's Disease Neuroimaging Initiative (ADNI), four different groups were defined (all of them matched by age, sex and education level): G1 (N1=36, healthy control subjects, Control), G2 (N2=36, early mild cognitive impairment, EMCI), G3 (N3=36, late mild cognitive impairment, LMCI) and G4 (N4=36, AD). Diffusion-tensor brain networks were compared across three disease stages: stage I 3(Control vs EMCI), stage II (Control vs LMCI) and stage III (Control vs AD). The group comparison was performed using the multivariate distance matrix regression analysis, a technique that was born in genomics and was recently proposed to handle brain functional networks, but here applied to diffusion-tensor data. The results were three-fold: First, no significant differences were found in stage I. Second, significant differences were found in stage II in the connectivity pattern of a subnetwork strongly associated to memory function (including part of the hippocampus, amygdala, entorhinal cortex, fusiform gyrus, inferior and middle temporal gyrus, parahippocampal gyrus and temporal pole). Third, a widespread disconnection across the entire AD brain was found in stage III, affecting more strongly the same memory subnetwork appearing in stage II, plus the other new subnetworks,including the default mode network, medial visual network, frontoparietal regions and striatum. Our results are consistent with a scenario where progressive alterations of connectivity arise as the disease severity increases and provide the brain areas possibly involved in such a degenerative process. Further studies applying the same strategy to longitudinal data are needed to fully confirm this scenario.

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The Role of Dietary and Lifestyle Factors in Maintaining Cognitive Health

American Journal of Lifestyle Medicine ◽

10.1177/1559827617701066 ◽

2017 ◽

Vol 12 (4) ◽

pp. 268-285 ◽

Cited By ~ 3

Author(s):

Nathalie E. Marchand ◽

Majken K. Jensen

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Lower Risk ◽

Controlled Trial ◽

Cognitive Health ◽

Healthy Diets ◽

Global Population

Concern over loss of cognitive function, including descent into Alzheimer’s disease or dementia, grips a growing percentage of men and women worldwide as the global population ages. Many studies, though not all, suggest that maintaining cognitive health, as well as slowing and even preventing cognitive decline, dementia, and Alzheimer’s disease, can be achieved by consuming healthy diets over a long enough period of time. This appears to be the case even for those who initiated dietary changes later in life, as evidenced by an intervention study assessing consumption of a healthy diet among those who were >50 years of age. All such diets share the common traits of being rich in fruits, vegetables, whole grains, and fish or seafood, while also being low in red meat and sweets. A Mediterranean-style diet shares these characteristics and has been associated with an estimated 40% lower risk of cognitive impairment, including mild cognitive impairment, dementia, and Alzheimer’s disease in prospective studies, in addition to being associated with both a 65% lower risk of mild cognitive impairment and improved cognitive performance in a notable randomized controlled trial.

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