scholarly journals The Beck Depression Inventory had low sensitivity and moderate specificity for detecting depression in patients with Alzheimer's disease

2000 ◽  
Vol 3 (3) ◽  
pp. 87-87
Author(s):  
R. Butler
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Beck Depression Inventory ◽  
Low Sensitivity

Differentiating Vascular Dementia from Alzhemer’s Disease with Brief Cognitive Tests

2014 ◽  
Vol 68 (1) ◽  
pp. 48-51
Author(s):  
Ivan Barbov ◽  
Ana Georgievska ◽  
Slavica Arsova ◽  
Snezhana Lazarova ◽  
Igor Petrov
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vascular Dementia ◽  
Roc Curves ◽  
The Elderly ◽  
Diagnostic Value ◽  
Cognitive Tests ◽  
Delayed Recall ◽  
Common Causes ◽  
Low Sensitivity

Abstract Introduction. Alzheimer’s disease (AD) and vascular dementia (VaD) are the most common causes of dementia in the elderly. The aim of this study was to investigate the diagnostic value of brief cognitive tests investigate the diagnostic value of brief cognitive tests in differentiating vascular dementia from Alzheimer’s disease. Methods. Fifteen patients with mild VaD, 15 patients with probable AD and 30 healthy controls, matched for age, education and dementia severity, were submitted to the following cognitive tests: clock drawing (free drqawing and copy), category of letter fluency, delayed recall test of figures and the EXIT 25 battery. Results. VaD patients performed worse than AD patients in category fluency (p=0.014), letter fluency (p=0.043) and CLOX 2 (p=0.023), while AD cases performed worse than VaD patients in delayed recall (p=0.013). However, Receiver Operating Characteristic (ROC) curves for these tests displayed low sensitivity and specificity for the differential diagnosis between VaD and AD. Conclusions. Altough the performance of VaD and AD patients was significantly different in some cognitive tests, the value of such instruments in differentiating VaD from AD proved to be very limited.

scholarly journals Limitations in differentiating vascular dementia from Alzheimer's disease with brief cognitive tests

2010 ◽  
Vol 68 (2) ◽  
pp. 185-188 ◽  
Author(s):  
Maria Niures P.S. Matioli ◽  
Paulo Caramelli
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Vascular Dementia ◽  
Recall Test ◽  
Roc Curves ◽  
Diagnostic Value ◽  
Cognitive Tests ◽  
Delayed Recall ◽  
Clock Drawing ◽  
Low Sensitivity

OBJECTIVE: To investigate the diagnostic value of brief cognitive tests in differentiating vascular dementia (VaD) from Alzheimer's disease (AD). METHOD: Fifteen patients with mild VaD, 15 patients with mild probable AD and 30 healthy controls, matched for age, education and dementia severity, were submitted to the following cognitive tests: clock drawing (free drawing and copy), category and letter fluency, delayed recall test of figures and the EXIT 25 battery. RESULTS: VaD patients performed worse than AD patients in category fluency (p=0.014), letter fluency (p=0.043) and CLOX 2 (p=0.023), while AD cases performed worse than VaD patients in delayed recall (p=0.013). However, ROC curves for these tests displayed low sensitivity and specificity for the differential diagnosis between VaD and AD. CONCLUSION: Although the performance of VaD and AD patients was significantly different in some cognitive tests, the value of such instruments in differentiating VaD from AD proved to be very limited.

Amyloid-β and Hyperphosphorylated Tau in the Prediction of Alzheimer’s Disease

2011 ◽  
Vol 6 (2) ◽  
pp. 84
Author(s):  
Jaana Rummukainen ◽  
Anne M Koivisto ◽  
Irina Alafuzoff ◽  
Ville Leinonen ◽  
◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Β ◽  
Brain Biopsy ◽  
High Sensitivity ◽  
High Specificity ◽  
Normal Pressure ◽  
Early Event ◽  
Hyperphosphorylated Tau ◽  
Low Sensitivity

Brain amyloid-β (Aβ) deposition is widely believed to be an early event in Alzheimer’s disease (AD). Aβ plaques, along with intracellular neurofibrillary tangles, which largely comprise hyperphosphorylated tau (HPτ), are considered to be neuropathological hallmarks of AD. Brain biopsies from living subjects could be used to evaluate these findings. It is possible to obtain biopsies from patients with presumed normal pressure hydrocephalus during diagnostic or shunt procedures. The presence of both Aβ and HPτ in frontal cortex biopsy samples seems to be a strong indicator of AD with high specificity (98 %) but rather low sensitivity (36 %). Aβ alone is associated with AD and exhibits high sensitivity (87 %) but lower specificity (69 %), indicating that many patients with Aβ only may also develop clinical dementia other than AD. Although a definite diagnosis of AD can only be confirmed at autopsy, brain biopsies may be useful for identification of novel markers of AD in a research context. In addition, when available, brain biopsy can be a useful diagnostic aid and validate non-invasive techniques in the diagnosis of dementia.

An Introduction to Ultrasensitive Assays for Plasma Tau Detection

2021 ◽  
Vol 80 (4) ◽  
pp. 1353-1362
Author(s):  
Xu-Long Ding ◽  
Qing-zhang Tuo ◽  
Peng Lei
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Fiber Optics ◽  
Single Molecule ◽  
Biomarker Discovery ◽  
Diagnostic Value ◽  
Meso Scale Discovery ◽  
Reduction Assay ◽  
Low Sensitivity ◽  
Serologic Assay

The detection of plasma tau and its phosphorylation is technically challenging due to the relatively low sensitivity. However, in Alzheimer’s disease and other tauopathies, it is hypothesized that tau in the biofluid may serve as a biomarker. In recent years, several ultrasensitive assays have been developed, which can successfully detect tau and its phosphorylation in various biofluids, and collectively demonstrated the prognostic and diagnostic value of plasma tau/phosphorylated tau. Here we have summarized the principle of four ultrasensitive assays newly developed suitable for plasma tau detection, namely single-molecule array, immunomagnetic reduction assay, enhanced immunoassay using multi-arrayed fiber optics, and meso scale discovery assay, with their advantages and applications. We have also compared these assays with traditional enzyme-linked-immunosorbent serologic assay, hoping to facilitate future tau-based biomarker discovery for Alzheimer’s disease and other neurodegenerative diseases.

Cognitive control constrains memory attributions

2019 ◽  
Vol 42 ◽  
Author(s):  
Colleen M. Kelley ◽  
Larry L. Jacoby
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Cognitive Control

Abstract Cognitive control constrains retrieval processing and so restricts what comes to mind as input to the attribution system. We review evidence that older adults, patients with Alzheimer's disease, and people with traumatic brain injury exert less cognitive control during retrieval, and so are susceptible to memory misattributions in the form of dramatic levels of false remembering.

Formation of paired helical filaments in Alzheimer's disease

1984 ◽  
Vol 42 ◽  
pp. 302-303
Author(s):  
J. Metuzals ◽  
D. F. Clapin ◽  
V. Montpetit
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Frontal Lobe ◽  
Giant Axon ◽  
Paired Helical Filaments ◽  
Normal Brain ◽  
Protein Assemblies ◽  
Electron Microscopic ◽  
Helical Symmetry ◽  
Structural Levels

Information on the conformation of paired helical filaments (PHF) and the neurofilamentous (NF) network is essential for an understanding of the mechanisms involved in the formation of the primary lesions of Alzheimer's disease (AD): tangles and plaques. The structural and chemical relationships between the NF and the PHF have to be clarified in order to discover the etiological factors of this disease. We are investigating by stereo electron microscopic and biochemical techniques frontal lobe biopsies from patients with AD and squid giant axon preparations. The helical nature of the lesion in AD is related to pathological alterations of basic properties of the nervous system due to the helical symmetry that exists at all hierarchic structural levels in the normal brain. Because of this helical symmetry of NF protein assemblies and PHF, the employment of structure reconstruction techniques to determine the conformation, particularly the handedness of these structures, is most promising. Figs. 1-3 are frontal lobe biopsies.

Computer-aided methods for 3-D visualization of serial sections and thick biological specimens

1992 ◽  
Vol 50 (2) ◽  
pp. 1060-1061
Author(s):  
Mark Ellisman ◽  
Maryann Martone ◽  
Gabriel Soto ◽  
Eleizer Masliah ◽  
David Hessler ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Three Dimensional ◽  
Neuritic Plaque ◽  
Dimensional Structure ◽  
Data Sets ◽  
Molecular Physiology ◽  
Research Activities ◽  
Computer Aided ◽  
Dimensional Reconstruction

Structurally-oriented biologists examine cells, tissues, organelles and macromolecules in order to gain insight into cellular and molecular physiology by relating structure to function. The understanding of these structures can be greatly enhanced by the use of techniques for the visualization and quantitative analysis of three-dimensional structure. Three projects from current research activities will be presented in order to illustrate both the present capabilities of computer aided techniques as well as their limitations and future possibilities.The first project concerns the three-dimensional reconstruction of the neuritic plaques found in the brains of patients with Alzheimer's disease. We have developed a software package “Synu” for investigation of 3D data sets which has been used in conjunction with laser confocal light microscopy to study the structure of the neuritic plaque. Tissue sections of autopsy samples from patients with Alzheimer's disease were double-labeled for tau, a cytoskeletal marker for abnormal neurites, and synaptophysin, a marker of presynaptic terminals.

Liquid crystalline ordering of paired helical filaments in neurofibrillary tangles of Alzheimer's disease

1986 ◽  
Vol 44 ◽  
pp. 348-349
Author(s):  
D.F. Clapin ◽  
V.J.A. Montpetit
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurofibrillary Tangles ◽  
Liquid Crystalline ◽  
Amyloid Fibrils ◽  
Geometric Analysis ◽  
Paired Helical Filaments ◽  
Microscopic Level ◽  
Light Microscopic Level ◽  
Regular Spacing

Alzheimer's disease is characterized by the accumulation of abnormal filamentous proteins. The most important of these are amyloid fibrils and paired helical filaments (PHF). PHF are located intraneuronally forming bundles called neurofibrillary tangles. The designation of these structures as "tangles" is appropriate at the light microscopic level. However, localized domains within individual tangles appear to demonstrate a regular spacing which may indicate a liquid crystalline phase. The purpose of this paper is to present a statistical geometric analysis of PHF packing.

Paired helical filaments (PHF) in rats: An experimental animal model for Alzheimer's disease

1987 ◽  
Vol 45 ◽  
pp. 842-843
Author(s):  
V.J.A. Montpetit ◽  
S. Dancea ◽  
S.W. French ◽  
D.F. Clapin
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Animal Model ◽  
Paired Helical Filaments ◽  
Ethanol Intoxication ◽  
Drg Neurons ◽  
Critical Difference ◽  
Suitable Animal Model ◽  
The Central Nervous System ◽  
Chronic Ethanol Intoxication

A continuing problem in Alzheimer research is the lack of a suitable animal model for the disease. The absence of neurofibrillary tangles of paired helical filaments is the most critical difference in the processes by which the central nervous system ages in most species other than man. However, restricting consideration to single phenomena, one may identify animal models for specific aspects of Alzheimer's disease. Abnormal fibers resembling PHF have been observed in dorsal root ganglia (DRG) neurons of rats in a study of chronic ethanol intoxication and spontaneously in aged rats. We present in this report evidence that PHF-like filaments occur in ethanol-treated rats of young age. In control animals lesions similar in some respects to our observations of cytoskeletal pathology in pyridoxine induced neurotoxicity were observed.Male Wistar BR rats (Charles River Labs) weighing 350 to 400 g, were implanted with a single gastrostomy cannula and infused with a liquid diet containing 30% of total calories as fat plus ethanol or isocaloric dextrose.

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