Executive dysfunction and periventricular diffusion tensor changes in amnesic mild cognitive impairment and early 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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The Effect of Cognitive Training in Patients with Mild Cognitive Impairment and Early Alzheimer's Disease: A Preliminary Study

Journal of Clinical Neurology ◽

10.3988/jcn.2012.8.3.190 ◽

2012 ◽

Vol 8 (3) ◽

pp. 190 ◽

Cited By ~ 17

Author(s):

Hye Ran Hwang ◽

Seong Hye Choi ◽

Dae Hyun Yoon ◽

Byung-Nam Yoon ◽

Young Ju Suh ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Cognitive Training ◽

Preliminary Study ◽

Early Alzheimer’S Disease

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Studies of implicit prototype extraction in patients with mild cognitive impairment and early Alzheimer's disease.

Journal of Experimental Psychology Learning Memory and Cognition ◽

10.1037/a0028064 ◽

2012 ◽

Vol 38 (4) ◽

pp. 860-880 ◽

Cited By ~ 8

Author(s):

Robert M. Nosofsky ◽

Stephen E. Denton ◽

Safa R. Zaki ◽

Anne F. Murphy-Knudsen ◽

Frederick W. Unverzagt

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Early Alzheimer’S Disease

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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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Working Memory and Executive Function Decline across Normal Aging, Mild Cognitive Impairment, and Alzheimer’s Disease

BioMed Research International ◽

10.1155/2015/748212 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 137

Author(s):

Anna-Mariya Kirova ◽

Rebecca B. Bays ◽

Sarita Lagalwar

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Working Memory ◽

Cognitive Impairment ◽

Executive Function ◽

Mild Cognitive Impairment ◽

Executive Dysfunction ◽

Normal Aging ◽

Future Research ◽

Neurological Differences

Alzheimer’s disease (AD) is a progressive neurodegenerative disease marked by deficits in episodic memory, working memory (WM), and executive function. Examples of executive dysfunction in AD include poor selective and divided attention, failed inhibition of interfering stimuli, and poor manipulation skills. Although episodic deficits during disease progression have been widely studied and are the benchmark of a probable AD diagnosis, more recent research has investigated WM and executive function decline during mild cognitive impairment (MCI), also referred to as the preclinical stage of AD. MCI is a critical period during which cognitive restructuring and neuroplasticity such as compensation still occur; therefore, cognitive therapies could have a beneficial effect on decreasing the likelihood of AD progression during MCI. Monitoring performance on working memory and executive function tasks to track cognitive function may signal progression from normal cognition to MCI to AD. The present review tracks WM decline through normal aging, MCI, and AD to highlight the behavioral and neurological differences that distinguish these three stages in an effort to guide future research on MCI diagnosis, cognitive therapy, and AD prevention.

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Diagnostic utility of sound naming in early Alzheimer’s disease

Journal of the International Neuropsychological Society ◽

10.1017/s135561770909033x ◽

2009 ◽

Vol 15 (2) ◽

pp. 231-238 ◽

Cited By ~ 4

Author(s):

HYEON-AE JEON ◽

KYOUNG-MIN LEE

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Picture Naming ◽

Temporal Cortex ◽

Cognitive Domain ◽

Diagnostic Utility ◽

Future Studies ◽

Early Alzheimer’S Disease

AbstractWhile it is well known that picture naming (PN) is impaired in Alzheimer’s disease (AD), sound naming (SN) has not been thoroughly investigated. We postulated that SN might be impaired more severely and earlier than PN, given the early involvement of the temporal cortex by AD-related pathology. SN and PN were assessed in 21 normal participants, 40 patients with mild cognitive impairment (MCI), and 27 patients in early stages of AD. Our results showed that SN accuracy and latency were more sensitive to advancing pathology in AD than PN accuracy and latency. SN was more useful and specific in distinguishing MCI patients from normal participants and therefore in potentially identifying the subset of MCI patients who already have impairment in more than one cognitive domain and may actually have incipient AD. These findings indicate a potential diagnostic utility of SN for early detection of the disease. Furthermore, even though most AD patients demonstrated more or less comparable impairment in both tasks, some were disproportionately impaired on SN and others were differentially impaired on PN. Future studies may be able to show that these discrepant groups correspond to patients with right and left hemisphere predominant AD, respectively. (JINS, 2009, 15, 231–238.)

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