scholarly journals Electroencephalography as a Non-Invasive Biomarker of Alzheimer’s Disease: A Forgotten Candidate to Substitute CSF Molecules?

2021 ◽  
Vol 22 (19) ◽  
pp. 10889
Author(s):  
Paloma Monllor ◽  
Ana Cervera-Ferri ◽  
Maria-Angeles Lloret ◽  
Daniel Esteve ◽  
Begoña Lopez ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Molecular Markers ◽  
Cost Effective ◽  
Disease Diagnosis ◽  
Therapeutic Interventions ◽  
Underlying Process ◽  
Non Invasive ◽  
Diagnosis And Prognosis ◽  
Over Time

Biomarkers for disease diagnosis and prognosis are crucial in clinical practice. They should be objective and quantifiable and respond to specific therapeutic interventions. Optimal biomarkers should reflect the underlying process (pathological or not), be reproducible, widely available, and allow measurements repeatedly over time. Ideally, biomarkers should also be non-invasive and cost-effective. This review aims to focus on the usefulness and limitations of electroencephalography (EEG) in the search for Alzheimer’s disease (AD) biomarkers. The main aim of this article is to review the evolution of the most used biomarkers in AD and the need for new peripheral and, ideally, non-invasive biomarkers. The characteristics of the EEG as a possible source for biomarkers will be revised, highlighting its advantages compared to the molecular markers available so far.

scholarly journals microRNAs as Early Biomarkers of Alzheimer’s Disease: A Synaptic Perspective

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 113
Author(s):  
Dolores Siedlecki-Wullich ◽  
Alfredo J. Miñano-Molina ◽  
José Rodríguez-Álvarez
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Time Window ◽  
Cost Effective ◽  
Synaptic Function ◽  
Therapeutic Interventions ◽  
Synaptic Homeostasis ◽  
Diagnosis And Prognosis ◽  
Individual Mirnas ◽  
Long Time

Pathogenic processes underlying Alzheimer’s disease (AD) affect synaptic function from initial asymptomatic stages, long time before the onset of cognitive decline and neurodegeneration. Therefore, reliable biomarkers enabling early AD diagnosis and prognosis are needed to maximize the time window for therapeutic interventions. MicroRNAs (miRNAs) have recently emerged as promising cost-effective and non-invasive biomarkers for AD, since they can be readily detected in different biofluids, including cerebrospinal fluid (CSF) and blood. Moreover, a growing body of evidence indicates that miRNAs regulate synaptic homeostasis and plasticity processes, suggesting that they may be involved in early synaptic dysfunction during AD. Here, we review the current literature supporting a role of miRNAs during early synaptic deficits in AD, including recent studies evaluating their potential as AD biomarkers. Besides targeting genes related to Aβ and tau metabolism, several miRNAs also regulate synaptic-related proteins and transcription factors implicated in early synaptic deficits during AD. Furthermore, individual miRNAs and molecular signatures have been found to distinguish between prodromal AD and healthy controls. Overall, these studies highlight the relevance of considering synaptic-related miRNAs as potential biomarkers of early AD stages. However, further validation studies in large cohorts, including longitudinal studies, as well as implementation of standardized protocols, are needed to establish miRNA-based biomarkers as reliable diagnostic and prognostic tools.

scholarly journals Proteins and microRNAs are differentially expressed in tear fluid from patients with Alzheimer’s disease

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Aidan Kenny ◽  
Eva M. Jiménez-Mateos ◽  
María Ascensión Zea-Sevilla ◽  
Alberto Rábano ◽  
Pablo Gili-Manzanaro ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Unmet Need ◽  
Cost Effective ◽  
Specific Protein ◽  
Tear Fluid ◽  
Initiation Factor ◽  
Non Invasive ◽  
A Genome ◽  
Potential Biomarker

Abstract Alzheimer’s disease (AD) is characterized by a progressive loss of neurons and cognitive functions. Therefore, early diagnosis of AD is critical. The development of practical and non-invasive diagnostic tests for AD remains, however, an unmet need. In the present proof-of-concept study we investigated tear fluid as a novel source of disease-specific protein and microRNA-based biomarkers for AD development using samples from patients with mild cognitive impairment (MCI) and AD. Tear protein content was evaluated via liquid chromatography-mass spectrometry and microRNA content was profiled using a genome-wide high-throughput PCR-based platform. These complementary approaches identified enrichment of specific proteins and microRNAs in tear fluid of AD patients. In particular, we identified elongation initiation factor 4E (eIF4E) as a unique protein present only in AD samples. Total microRNA abundance was found to be higher in tears from AD patients. Among individual microRNAs, microRNA-200b-5p was identified as a potential biomarker for AD with elevated levels present in AD tear fluid samples compared to controls. Our study suggests that tears may be a useful novel source of biomarkers for AD and that the identification and verification of biomarkers within tears may allow for the development of a non-invasive and cost-effective diagnostic test for AD.

IS A LARGE-SCALE SCREENING FOR ALZHEIMER’S DISEASE POSSIBLE? YES, IN A FEW YEARS

2019 ◽  
pp. 1-2
Author(s):  
F. Ribaldi ◽  
D. Altomare ◽  
G.B. Frisoni
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Large Scale ◽  
Task Force ◽  
Cost Effective ◽  
The European Union ◽  
New Era ◽  
Non Invasive ◽  
Recent Meeting ◽  
Large Scale Screening

Recent evidence on blood-based biomarkers is pointing the way towards a new era of large-scale, feasible, cost-effective and non-invasive screening for Alzheimer’s disease (AD). This was one of the main focuses of the recent meeting of the European Union-North American Clinical Trials in AD (EU/US CTAD) Task Force, which took place in Barcelona in October 24-27, 2018, and convened drug and diagnostics developers from industry and academia in order to define a roadmap for the development and marketing of blood-based biomarkers (1).

scholarly journals A Non Invasive Biomarkers for Alzheimer’s disease Detection

2019 ◽  
Vol 8 (2S5) ◽  
pp. 1-6
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Brain Region ◽  
Healthcare Costs ◽  
Elderly Population ◽  
Life Quality ◽  
Patient Specific ◽  
Non Invasive ◽  
Over Time

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases occurring in elderly population worldwide, which usually starts slowly and worsens over time. AD is generally diagnosed too late, when irreversible damages have been caused in the patient’s brain region. Present need demands the discovery of diagnostic and prognostic patient specific effective biomarkers to improve patient’s life quality and avoid big healthcare costs. Objective of this survey is to review the non-invasive biomarkers that could be used to predict early onset of AD and delay cognitive impairment.

scholarly journals Article Commentary: Alzheimer's Disease, Diagnosis and the Need for Biomarkers

2008 ◽  
Vol 3 ◽  
pp. BMI.S682 ◽  
Author(s):  
Claudie Hooper ◽  
Simon Lovestone ◽  
Ricardo Sainz-Fuertes
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Memory Loss ◽  
Cost Effective ◽  
Predictive Biomarker ◽  
Disease Diagnosis ◽  
Response To Therapy ◽  
Histopathological Analysis

Alzheimer's disease (AD) is a progressive neurodegenerative disorder of aging that presents with memory loss, disorientation, confusion and a reduction in cognitive ability. Although a definite diagnosis of the disorder can only be made post-mortem by histopathological analysis, a number of methods are currently available for the in vivo assessment of AD including psycho-metric tests and neuro-imaging. However, these clinical assessments are relatively nonspecific and imaging is very costly. Genetic testing can be performed if familial AD is suspected, although such cases represent a very small minority of total AD cases. Apolipoprotein E genotype provides a measure for analysing the risk of developing AD, but does not act as an absolute predictive biomarker for AD. Therefore there is a need for an accurate, universal, specific and cost-effective biomarker to facilitate not only ante-mortem diagnosis of AD, but also to allow progression of the disease and response to therapy to be monitored. This is the ultimate goal that our group is pursuing through the pan-European AddNeuroMed project.

scholarly journals Promise and Challenge: The Lens Model as a Biomarker for Early Diagnosis of Alzheimer's Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Tian Tian ◽  
Boai Zhang ◽  
Yanjie Jia ◽  
Zhaoming Li
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Early Diagnosis ◽  
Accurate Diagnosis ◽  
Lens Model ◽  
Non Invasive ◽  
Diagnosis And Prognosis ◽  
Protein Deposits ◽  
Age Related ◽  
The Brain

Alzheimer’s disease (AD) is the most common form of dementia pathologically characterized by cerebral amyloid-beta (Aβ) deposition. Early and accurate diagnosis of the disease still remains a big challenge. There is evidence that Aβaggregation starts to occur years before symptoms arise. Noninvasive monitoring of Aβplaques is critical for both the early diagnosis and prognosis of AD. Presently, there is a major effort on looking for a reasonably priced technology capable of diagnosing AD by detecting the presence of Aβ. Studies suggest that AD is systemic rather than brain-limited focus diseases and the aggregation of the disease-causing proteins also takes place in lens except the brain. There is a possible relationship between AD and a specific subtype of age-related cataract (supranuclear cataract). If similar abnormal protein deposits are present in the lens, it would facilitate non-invasive diagnosis and monitoring of disease progression. However, there are controversies on the issues related to performance and validation of Aβdeposition in lens as biomarkers for early detection of AD. Here we review the recent findings concerning Aβdeposition in the lenses of AD patients and evaluate if the ocular lens can provide a biomarker for AD.

scholarly journals Multiplexed Immunoassay Panel Identifies Novel CSF Biomarkers for Alzheimer's Disease Diagnosis and Prognosis

PLoS ONE ◽  
2011 ◽  
Vol 6 (4) ◽  
pp. e18850 ◽  
Author(s):  
Rebecca Craig-Schapiro ◽  
Max Kuhn ◽  
Chengjie Xiong ◽  
Eve H. Pickering ◽  
Jingxia Liu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Disease Diagnosis ◽  
Csf Biomarkers ◽  
Diagnosis And Prognosis ◽  
Alzheimer’S Disease Diagnosis ◽  
Multiplexed Immunoassay

scholarly journals Near-Infrared Optical Spectroscopy In Vivo Distinguishes Subjects with Alzheimer’s Disease from Age-Matched Controls

2021 ◽  
pp. 1-12
Author(s):  
Frank A. Greco ◽  
Ann C. McKee ◽  
Neil W. Kowall ◽  
Eugene B. Hanlon
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Optical Spectroscopy ◽  
Near Infrared ◽  
Therapeutic Interventions ◽  
Non Invasive ◽  
Normal Human ◽  
Feature Selection Approach

Background: Medical imaging methods such as PET and MRI aid clinical assessment of Alzheimer’s disease (AD). Less expensive, less technically demanding, and more widely deployable technologies are needed to expand objective screening for diagnosis, treatment, and research. We previously reported brain tissue near-infrared optical spectroscopy (NIR) in vitro indicating the potential to meet this need. Objective: To determine whether completely non-invasive, clinical, NIR in vivo can distinguish AD patients from age-matched controls and to show the potential of NIR as a clinical screen and monitor of therapeutic efficacy. Methods: NIR spectra were acquired in vivo. Three groups were studied: autopsy-confirmed AD, control and mild cognitive impairment (MCI). A feature selection approach using the first derivative of the intensity normalized spectra was used to discover spectral regions that best distinguished “AD-alone” (i.e., without other significant neuropathology) from controls. The approach was then applied to other autopsy-confirmed AD cases and to clinically diagnosed MCI cases. Results: Two regions about 860 and 895 nm completely separate AD patients from controls and differentiate MCI subjects according to the degree of impairment. The 895 nm feature is more important in separating MCI subjects from controls (ratio-of-weights: 1.3); the 860 nm feature is more important for distinguishing MCI from AD (ratio-of-weights: 8.2). Conclusion: These results form a proof of the concept that near-infrared spectroscopy can detect and classify diseased and normal human brain in vivo. A clinical trial is needed to determine whether the two features can track disease progression and monitor potential therapeutic interventions.

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