scholarly journals Perceptual Organization Based Upon Spatial Relationships in Alzheimer’s Disease

2003 ◽  
Vol 14 (1-2) ◽  
pp. 19-28 ◽  
Author(s):  
Daniel D. Kurylo ◽  
Walter C. Allan ◽  
T. Edward Collins ◽  
Joshua Baron
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Perceptual Organization ◽  
Visual Information ◽  
Functional Decline ◽  
Regional Distribution ◽  
Control Group ◽  
Spatial Relationships ◽  
Control Subjects ◽  
Elderly Control

Alzheimer’s disease (AD) is often accompanied by impaired object recognition, thereby reducing the ability to recognize common objects and familiar faces. Impaired recognition may stem from decreased efficacy in integrating visual information. Studies of perceptual abnormalities in AD indicate an impairment in organizing elements of the visual scene, thereby confusing components of individual forms. This type of impairment is consistent with the characteristics of neural loss, which impact cortical integration. To examine the extent to which perceptual organization is impaired in AD, psychophysical measurements were made of visual perceptual grouping based upon spatial relationships in a group of AD patients and demographically matched elderly control subjects. A comparison was also made between young and elderly control subjects to evaluate the effects of aging on these capacities. Deficits in perceptual organization were found for a subgroup of AD patients, which corresponded to impairment on facial recognition. A less profound functional decline was found for the elderly control group. The degree of impairment for AD subjects did not correlate to level of dementia, but instead appears to be idiosyncratic to individual patients. These results are consistent with impaired integrative function in AD, the degree of which reflects individual differences in the regional distribution of neuropathological changes.

scholarly journals Assessment of balance in mild and moderate stages of Alzheimer's disease: implications on falls and functional capacity

2011 ◽  
Vol 69 (2a) ◽  
pp. 202-207 ◽  
Author(s):  
Eliane Mayumi Kato-Narita ◽  
Ricardo Nitrini ◽  
Marcia Radanovic
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Functional Capacity ◽  
Functional Decline ◽  
Berg Balance Scale ◽  
Control Group ◽  
Disability Assessment ◽  
Balance Impairment ◽  
Balance Scale

OBJECTIVE: To analyze the correlation between balance, falls and loss of functional capacity in mild and moderate Alzheimer's disease(AD). METHOD: 40 subjects without cognitive impairment (control group) and 48 AD patients (25 mild, 23 moderate) were evaluated with the Berg Balance Scale (BBS) and the Disability Assessment for Dementia (DAD). Subjects answered a questionnaire about falls occurrence in the last twelve months. RESULTS: Moderate AD patients showed poorer balance (p=0.001) and functional capacity (p <0.0001) and it was observed a correlation between falls and balance (r= -0.613; p=0.045). CONCLUSION: There is a decline of balance related to AD which is a factor associated to the occurrence of falls, albeit not the most relevant one. The loss of functional capacity is associated with the disease's progress but not to a higher occurrence of falls. The balance impairment did not correlate with functional decline in AD patients.

scholarly journals The neuropsychological profiles of mild Alzheimer's disease and questionable dementia as compared to age-related cognitive decline

2003 ◽  
Vol 9 (5) ◽  
pp. 720-732 ◽  
Author(s):  
ELISE CACCAPPOLO-VAN VLIET ◽  
JENNIFER MANLY ◽  
MING-XIN TANG ◽  
KAREN MARDER ◽  
KAREN BELL ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
The Elderly ◽  
Cognitive Domain ◽  
Group Status ◽  
Control Subjects ◽  
Mini Mental Status Exam ◽  
Age Related ◽  
Questionable Dementia ◽  
Elderly Control

Test scores from a comprehensive neuropsychological battery administered to 1602 subjects consisting of 1347 subjects with probable Alzheimer's disease (AD), 100 subjects with questionable dementia (QD) and 155 non-demented elderly control subjects were cross-sectionally analyzed. Subjects with probable AD were categorized as mild (n = 244), moderate (n = 480), severe (n = 376), and very severe (n = 247) according to modified mini mental status exam (mMMSE) scores. Mean scores on individual neuropsychological tests are provided for each group of subjects. Stratified random sampling was performed to select a sample of mild AD subjects who were matched in age and education to non-demented elderly controls, and analyses focused on the performance of QD subjects and mild AD subjects, whose scores were compared to those of the elderly control subjects. Selected scores were organized by cognitive domain and logistic regressions were used to determine the domains and individual tests within each that were most predictive of group status. Results suggested a profile of scores associated with QD and mild AD including impaired recall of verbal information for both groups. Areas of lower functioning in QD subjects as compared to elderly controls included category fluency and visuospatial ability. (JINS, 2003, 9, 720–732.)

Blood–Brain Barrier Integrity in Alzheimer's Disease Patients and Elderly Control Subjects

1998 ◽  
Vol 10 (1) ◽  
pp. 78-84 ◽  
Author(s):  
Maria T. Caserta ◽  
Daniel Caccioppo ◽  
Gregory D. Lapin ◽  
Ann Ragin ◽  
Dennis R. Groothuis
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Barrier Integrity ◽  
Control Subjects ◽  
Blood Brain ◽  
Elderly Control ◽  
Blood Brain Barrier Integrity

scholarly journals Visual Perceptual Organization Ability in Autopsy-Verified Dementia with Lewy Bodies and Alzheimer’s Disease

2016 ◽  
Vol 22 (6) ◽  
pp. 609-619 ◽  
Author(s):  
Micaela Mitolo ◽  
Joanne M. Hamilton ◽  
Kelly M. Landy ◽  
Lawrence A. Hansen ◽  
Douglas Galasko ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Perceptual Organization ◽  
Visual Information ◽  
Dementia With Lewy Bodies ◽  
Lewy Bodies ◽  
Braak Stage ◽  
Patient Groups ◽  
Diagnostic Sensitivity And Specificity ◽  
Visual Perceptual Organization

AbstractObjectives:Prominent impairment of visuospatial processing is a feature of dementia with Lewy bodies (DLB), and diagnosis of this impairment may help clinically distinguish DLB from Alzheimer’s disease (AD). The current study compared autopsy-confirmed DLB and AD patients on the Hooper Visual Organization Test (VOT), a test that requires perceptual and mental reorganization of parts of an object into an identifiable whole. The VOT may be particularly sensitive to DLB since it involves integration of visual information processed in separate dorsal and ventral visual “streams”.Methods:Demographically similar DLB (n=28), AD (n=115), and normal control (NC;n=85) participants were compared on the VOT and additional neuropsychological tests. Patient groups did not differ in dementia severity at time of VOT testing. High and Low AD-Braak stage DLB subgroups were compared to examine the influence of concomitant AD pathology on VOT performance.Results:Both patient groups were impaired compared to NC participants. VOT scores of DLB patients were significantly lower than those of AD patients. The diagnostic sensitivity and specificity of the VOT for patientsversuscontrols was good, but marginal for DLBversusAD. High-Braak and low-Braak DLB patients did not differ on the VOT, but High-Braak DLB performed worse than Low-Braak DLB on tests of episodic memory and language.Conclusions:Visual perceptual organization ability is more impaired in DLB than AD but not strongly diagnostic. The disproportionate severity of this visual perceptual deficit in DLB is not related to degree of concomitant AD pathology, which suggests that it might primarily reflect Lewy body pathology. (JINS, 2016,22, 609–619)

Age of Onset and Brain Atrophy in Alzheimer's Disease

1997 ◽  
Vol 9 (2) ◽  
pp. 183-196 ◽  
Author(s):  
Jong Inn Woo ◽  
Ju Han Kim ◽  
Jung Hie Lee
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Age Of Onset ◽  
Interaction Analysis ◽  
Strong Predictor ◽  
Cerebral Atrophy ◽  
Control Group ◽  
Control Subjects ◽  
Duration Of Illness ◽  
Cerebral Degeneration

Using magnetic resonance imaging-based planimetry, we measured cortical and cerebral (cortical and ventricular) atrophy in 26 patients with Alzheimer's disease (AD) (age, 72.2 ± 7.0) according to NINCDS-ADRDA criteria and 22 control subjects (age, 71.5 ± 5.4). AD patients exhibited greater cerebral atrophy (p < .05) than control subjects. Cerebral atrophy was significantly correlated with age (r = .72, p < .0005) in healthy volunteers but not in AD patients. In AD patients, age of onset was negatively correlated with the estimated rate of disease-attributed cerebral degeneration ([observed atrophy - atrophy in normal aging calculated from the regression equation derived from the control group]/[duration of illness]) (r = −.54, p < .005). Multiple regression with interaction analysis demonstrated that age, age of onset, and their interaction successfully explained cerebral (R2 = .51, p < .05) and cortical (R2 = .64, p < .05) atrophy in patients with probable AD. Age of onset may be a strong predictor of the rate of cerebral degeneration in AD, and our results suggest that controlling age and the age of onset is essential in the quantitative study of AD.

scholarly journals Influence of PICALM and CLU risk variants on beta EEG activity in Alzheimer’s disease patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aarón Maturana-Candelas ◽  
Carlos Gómez ◽  
Jesús Poza ◽  
Víctor Rodríguez-González ◽  
Vìctor Gutiérrez-de Pablo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Regional Distribution ◽  
Control Group ◽  
Protective Effects ◽  
Beta Band ◽  
Eeg Activity ◽  
Spatial Entropy ◽  
Beta Power ◽  
The Brain

AbstractPICALM and CLU genes have been linked to alterations in brain biochemical processes that may have an impact on Alzheimer’s disease (AD) development and neurophysiological dynamics. The aim of this study is to analyze the relationship between the electroencephalographic (EEG) activity and the PICALM and CLU alleles described as conferring risk or protective effects on AD patients and healthy controls. For this purpose, EEG activity was acquired from: 18 AD patients and 12 controls carrying risk alleles of both PICALM and CLU genes, and 35 AD patients and 12 controls carrying both protective alleles. Relative power (RP) in the conventional EEG frequency bands (delta, theta, alpha, beta, and gamma) was computed to quantify the brain activity at source level. In addition, spatial entropy (SE) was calculated in each band to characterize the regional distribution of the RP values throughout the brain. Statistically significant differences in global RP and SE at beta band (p-values < 0.05, Mann–Whitney U-test) were found between genotypes in the AD group. Furthermore, RP showed statistically significant differences in 58 cortical regions out of the 68 analyzed in AD. No statistically significant differences were found in the control group at any frequency band. Our results suggest that PICALM and CLU AD-inducing genotypes are involved in physiological processes related to disruption in beta power, which may be associated with physiological disturbances such as alterations in beta-amyloid and neurotransmitter metabolism.

Altered Vergence Eye Movements and Pupil Response of Patients with Alzheimer’s Disease and Mild Cognitive Impairment During an Oddball Task

2021 ◽  
pp. 1-13
Author(s):  
Elizabeth Carolina Jiménez ◽  
Alba Sierra-Marcos ◽  
August Romeo ◽  
Amin Hashemi ◽  
Oleksii Leonovych ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Processing ◽  
Visual Information ◽  
Control Group ◽  
Support Tool ◽  
Pupil Response ◽  
Oddball Task

Background: Alzheimer’s disease (AD) is characterized by progressive deterioration of cognitive functions and may be preceded by mild cognitive impairment (MCI). Evidence shows changes in pupil and vergence responses related to cognitive processing of visual information. Objective: Here we test the hypothesis that MCI and AD are associated with specific patterns in vergence and pupil responses. Methods: We employed a visual oddball task. In the distractor condition (80%of the trials), a blue stimulus was presented whereas in the target condition (20%of trials) it was red. Participants (23 Controls, 33 MCI patients, and 18 AD patients) were instructed to press a button when a target appeared. Results: Participants briefly converged their eyes 200 ms after stimulus presentation. In controls, this transient peak response was followed by a delay response to targets but not to distractor stimuli. In the patient groups, delay responses to distractors were noticed. Consequently, the differential vergence response was strong in the control group, weak in the MCI group, and absent in the AD group. Pupils started to dilate 500–600 ms after the appearance of a target but slightly contracted after the presentation of a distractor. This differential pupil response was strongest in the AD group. Conclusion: Our findings support the idea of a role of vergence and pupil responses in attention and reveal altered responses in MCI and AD patients. Further studies should assess the value of vergence and pupil measurements as an objective support tool for early diagnosis of AD.

Plasma Levels of Amyloid-β Peptides and Tau Protein in Mexican Patients with Alzheimer’s Disease

2021 ◽  
pp. 1-11
Author(s):  
Tzayaka Castillo-Mendieta ◽  
Yoaly Arana-Lechuga ◽  
Victoria Campos-Peña ◽  
Ana Luisa Sosa ◽  
Sandra Orozco-Suarez ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Amyloid Β ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Plasma Biomarkers ◽  
Control Subjects ◽  
And Control ◽  
T Tau

Background: Alzheimer’s disease (AD) causes memory deficit and alterations in other cognitive functions, mainly in adults over 60 years of age. As the diagnosis confirmation is performed by a postmortem neuropathological examination of the brain, this disease can be confused with other types of dementia at early stages. About 860,000 Mexicans are affected by dementia, most of them with insufficient access to adequate comprehensive health care services. Plasma biomarkers could be a rapid option for early diagnosis of the disease. Objective: This study aimed to analyze some plasma biomarkers (amyloid-β, tau, and lipids) in Mexican AD patients and control subjects with no associated neurodegenerative diseases. Methods: Plasma amyloid-β peptides (Aβ 40 and Aβ 42), total and phosphorylated tau protein (T-tau and P-tau), and cholesterol and triglyceride levels were quantified enzyme-linked immunosorbent assay in AD patients and control subjects. Results: In Mexican AD patients, we found significantly lower levels of Aβ 42 (p <  0.05) compared to the control group. In contrast, significantly higher levels of P-tau (p <  0.05) and triglycerides (p <  0.05) were observed in AD patients compared to controls. Furthermore, a significant correlation was found between the severity of dementia and plasma P-tau levels, Aβ 42/Aβ 40 and P-tau/T-tau ratios, and triglycerides concentrations. This correlation increased gradually with cognitive decline. Conclusion: The detection of these plasma biomarkers is an initial step in searching for a timely, less invasive, and cost-efficient diagnosis in Mexicans.

scholarly journals Functional decline in the elderly with MCI: Cultural adaptation of the ADCS-ADL scale

2017 ◽  
Vol 63 (7) ◽  
pp. 590-599 ◽  
Author(s):  
Fabiana Carla Matos da Cunha Cintra ◽  
Marco Túlio Gualberto Cintra ◽  
Rodrigo Nicolato ◽  
Laiss Bertola ◽  
Rafaela Teixeira Ávila ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Likelihood Ratio ◽  
Predictive Value ◽  
Functional Decline ◽  
Positive Likelihood Ratio ◽  
Negative Likelihood Ratio ◽  
Control Group ◽  
P Value ◽  
Cognitive Screening

Summary Objective: Translate, transcultural adaptation and application to Brazilian Portuguese of the Alzheimer’s Disease Cooperative Study - Activities of Daily Living (ADCS-ADL) scale as a cognitive screening instrument. Method: We applied the back translation added with pretest and bilingual methods. The sample was composed by 95 elderly individuals and their caregivers. Thirty-two (32) participants were diagnosed as mild cognitive impairment (MCI) patients, 33 as Alzheimer’s disease (AD) patients and 30 were considered as cognitively normal individuals. Results: There were only little changes on the scale. The Cronbach alpha coefficient was 0.89. The scores were 72.9 for control group, followed by MCI (65.1) and by AD (55.9), with a p-value < 0.001. The ROC curve value was 0.89. We considered a cut point of 72 and we observed a sensibility of 86.2%, specificity of 70%, positive predictive value of 86.2%, negative predictive value of 70%, positive likelihood ratio of 2.9 and negative likelihood ratio of 0.2. Conclusion: ADCS-ADL scale presents satisfactory psychometric properties to discriminate between MCI, AD and normal cognition.

Validation of the Hungarian version of Alzheimer’s Disease Assessment Scale – Cognitive Subscale

2012 ◽  
Vol 153 (12) ◽  
pp. 461-466 ◽  
Author(s):  
Magdolna Pákáski ◽  
Gergely Drótos ◽  
Zoltán Janka ◽  
János Kálmán
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mental State ◽  
Mini Mental State Examination ◽  
Assessment Scale ◽  
Disease Assessment ◽  
Control Subjects ◽  
Cognitive Subscale ◽  
State Examination ◽  
Hungarian Version

The cognitive subscale of the Alzheimer’s Disease Assessment Scale is the most widely used test in the diagnostic and research work of Alzheimer’s disease. Aims: The aim of this study was to validate and investigate reliability of the Hungarian version of the Alzheimer’s Disease Assessment Scale in patients with Alzheimer’s disease and healthy control subjects. Methods: syxty-six patients with mild and moderate Alzheimer’s disease and 47 non-demented control subjects were recruited for the study. The cognitive status was established by the Hungarian version of the Alzheimer’s Disease Assessment Scale and Mini Mental State Examination. Discriminative validity, the relation between age and education and Alzheimer’s Disease Assessment Scale, and the sensitivity and specificity of the test were determined. Results: Both the Mini Mental State Examination and the Alzheimer’s Disease Assessment Scale had significant potential in differentiating between patients with mild and moderate stages of Alzheimer’s disease and control subjects. A very strong negative correlation was established between the scores of the Mini Mental State Examination and the Alzheimer’s Disease Assessment Scale in the Alzheimer’s disease group. The Alzheimer’s Disease Assessment Scale showed slightly negative relationship between education and cognitive performance, whereas a positive correlation between age and Alzheimer’s Disease Assessment Scale scores was detected only in the control group. According to the analysis of the ROC curve, the values of sensitivity and specificity of the Alzheimer’s Disease Assessment Scale were high. Conclusions: The Hungarian version of the Alzheimer’s Disease Assessment Scale was found to be highly reliable and valid and, therefore, the application of this scale can be recommended for the establishment of the clinical stage and follow-up of patients with Alzheimer’s disease. However, the current Hungarian version of the Alzheimer’s Disease Assessment Scale is not sufficient; the list of words and linguistic elements should be selected according to the Hungarian standard in the future. Orv. Hetil., 2012, 153, 461–466.

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