scholarly journals Complexity Measures for Quantifying Changes in Electroencephalogram in Alzheimer’s Disease

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Ali H. Husseen Al-Nuaimi ◽  
Emmanuel Jammeh ◽  
Lingfen Sun ◽  
Emmanuel Ifeachor
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Early Diagnosis ◽  
Clinical Manifestations ◽  
Quantitative Measure ◽  
Complexity Measures ◽  
Cross Sectional ◽  
Frequency Bands ◽  
Brain Functions ◽  
Early Stages

Alzheimer’s disease (AD) is a progressive disorder that affects cognitive brain functions and starts many years before its clinical manifestations. A biomarker that provides a quantitative measure of changes in the brain due to AD in the early stages would be useful for early diagnosis of AD, but this would involve dealing with large numbers of people because up to 50% of dementia sufferers do not receive formal diagnosis. Thus, there is a need for accurate, low-cost, and easy to use biomarkers that could be used to detect AD in its early stages. Potentially, electroencephalogram (EEG) based biomarkers can play a vital role in early diagnosis of AD as they can fulfill these needs. This is a cross-sectional study that aims to demonstrate the usefulness of EEG complexity measures in early AD diagnosis. We have focused on the three complexity methods which have shown the greatest promise in the detection of AD, Tsallis entropy (TsEn), Higuchi Fractal Dimension (HFD), and Lempel-Ziv complexity (LZC) methods. Unlike previous approaches, in this study, the complexity measures are derived from EEG frequency bands (instead of the entire EEG) as EEG activities have significant association with AD and this has led to enhanced performance. The results show that AD patients have significantly lower TsEn, HFD, and LZC values for specific EEG frequency bands and for specific EEG channels and that this information can be used to detect AD with a sensitivity and specificity of more than 90%.

scholarly journals Neuropsychological and neuroimaging changes in preclinical Alzheimer's disease

2006 ◽  
Vol 12 (5) ◽  
pp. 707-735 ◽  
Author(s):  
ELIZABETH W. TWAMLEY ◽  
SUSAN A. LEGENDRE ROPACKI ◽  
MARK W. BONDI
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Temporal Lobe ◽  
Functional Neuroimaging ◽  
Neuropsychological Functioning ◽  
Clinical Manifestations ◽  
Symptomatic Treatment ◽  
Cross Sectional ◽  
Preclinical Ad ◽  
Normal Individuals

Alzheimer's disease (AD) is a common, devastating form of dementia. With the advent of promising symptomatic treatment, the importance of recognizing AD at its very earliest stages has increased. We review the extant neuropsychological and neuroimaging literature on preclinical AD, focusing on longitudinal studies of initially nondemented individuals and cross-sectional investigations comparing at-risk with normal individuals. We systematically reviewed 91 studies of neuropsychological functioning, structural neuroimaging, or functional neuroimaging in preclinical AD. The neuropsychological studies indicated that preclinical AD might be characterized by subtle deficits in a broad range of neuropsychological domains, particularly in attention, learning and memory, executive functioning, processing speed, and language. Recent findings from neuroimaging research suggest that volume loss and cerebral blood flow or metabolic changes, particularly in the temporal lobe, may be detected before the onset of dementia. There exist several markers of a preclinical period of AD, in which specific cognitive and biochemical changes precede the clinical manifestations. The preclinical indicators of AD reflect early compromise of generalized brain integrity and temporal lobe functioning in particular. (JINS, 2006,12, 707–735.)

scholarly journals Intracerebral Injection of Extracellular Vesicles from Mesenchymal Stem Cells Exerts Reduced Aβ Plaque Burden in Early Stages of a Preclinical Model of Alzheimer’s Disease

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1059 ◽  
Author(s):  
Chiara A. Elia ◽  
Matteo Tamborini ◽  
Marco Rasile ◽  
Genni Desiato ◽  
Sara Marchetti ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Extracellular Vesicles ◽  
Clinical Manifestations ◽  
Plaque Burden ◽  
Intracerebral Injection ◽  
Early Stages ◽  
Β Amyloid

Bone marrow Mesenchymal Stem Cells (BM-MSCs), due to their strong protective and anti-inflammatory abilities, have been widely investigated in the context of several diseases for their possible therapeutic role, based on the release of a highly proactive secretome composed of soluble factors and Extracellular Vesicles (EVs). BM-MSC-EVs, in particular, convey many of the beneficial features of parental cells, including direct and indirect β-amyloid degrading-activities, immunoregulatory and neurotrophic abilities. Therefore, EVs represent an extremely attractive tool for therapeutic purposes in neurodegenerative diseases, including Alzheimer’s disease (AD). We examined the therapeutic potential of BM-MSC-EVs injected intracerebrally into the neocortex of APPswe/PS1dE9 AD mice at 3 and 5 months of age, a time window in which the cognitive behavioral phenotype is not yet detectable or has just started to appear. We demonstrate that BM-MSC-EVs are effective at reducing the Aβ plaque burden and the amount of dystrophic neurites in both the cortex and hippocampus. The presence of Neprilysin on BM-MSC-EVs, opens the possibility of a direct β-amyloid degrading action. Our results indicate a potential role for BM-MSC-EVs already in the early stages of AD, suggesting the possibility of intervening before overt clinical manifestations.

p35 Deficiency Accelerates HMGB-1-mediated Neuronal Death in the Early Stages of an Alzheimer’s disease Mouse Model

2013 ◽  
Vol 10 (8) ◽  
pp. 829-843 ◽  
Author(s):  
Ahram Jang ◽  
Hyunjeong Liew ◽  
Yun-Mi Kim ◽  
Heesoon Choi ◽  
Saeromi Kim ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Neuronal Death ◽  
Early Stages

Dehydroepiandrosterone (DHEA) and its Sulphate (DHEAS) in Alzheimer’s Disease

2020 ◽  
Vol 17 (2) ◽  
pp. 141-157 ◽  
Author(s):  
Dubravka S. Strac ◽  
Marcela Konjevod ◽  
Matea N. Perkovic ◽  
Lucija Tudor ◽  
Gordana N. Erjavec ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Large Scale ◽  
Therapeutic Potential ◽  
Relevant Literature ◽  
Comprehensive Overview ◽  
Brain Functions ◽  
Specific Effects ◽  
And Behavior

Background: Neurosteroids Dehydroepiandrosterone (DHEA) and Dehydroepiandrosterone Sulphate (DHEAS) are involved in many important brain functions, including neuronal plasticity and survival, cognition and behavior, demonstrating preventive and therapeutic potential in different neuropsychiatric and neurodegenerative disorders, including Alzheimer’s disease. Objective: The aim of the article was to provide a comprehensive overview of the literature on the involvement of DHEA and DHEAS in Alzheimer’s disease. Method: PubMed and MEDLINE databases were searched for relevant literature. The articles were selected considering their titles and abstracts. In the selected full texts, lists of references were searched manually for additional articles. Results: We performed a systematic review of the studies investigating the role of DHEA and DHEAS in various in vitro and animal models, as well as in patients with Alzheimer’s disease, and provided a comprehensive discussion on their potential preventive and therapeutic applications. Conclusion: Despite mixed results, the findings of various preclinical studies are generally supportive of the involvement of DHEA and DHEAS in the pathophysiology of Alzheimer’s disease, showing some promise for potential benefits of these neurosteroids in the prevention and treatment. However, so far small clinical trials brought little evidence to support their therapy in AD. Therefore, large-scale human studies are needed to elucidate the specific effects of DHEA and DHEAS and their mechanisms of action, prior to their applications in clinical practice.

A Transfer Learning Approach for Early Diagnosis of Alzheimer’s Disease on MRI Images

Neuroscience ◽  
2021 ◽  
Author(s):  
Atif Mehmood ◽  
Shuyuan yang ◽  
Zhixi feng ◽  
Min wang ◽  
AL Smadi Ahmad ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Early Diagnosis ◽  
Transfer Learning ◽  
Learning Approach
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