scholarly journals Retest reliability of balance and mobility measurements in people with mild to moderate Alzheimer's disease

2011 ◽  
Vol 23 (7) ◽  
pp. 1152-1159 ◽  
Author(s):  
Plaiwan Suttanon ◽  
Keith D. Hill ◽  
Karen J. Dodd ◽  
Catherine M. Said
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mixed Model ◽  
Intraclass Correlation ◽  
Step Length ◽  
Clinical Test ◽  
Retest Reliability ◽  
Relative Reliability ◽  
Manual Task ◽  
Minimum Detectable Change

ABSTRACTBackground: To interpret changes of balance and mobility in people with Alzheimer's disease (AD), we require measures of balance and mobility that have demonstrated reliability in this population. The aim of the study was to determine the safety, feasibility and retest reliability of clinical and forceplate balance and mobility measurements in people with AD.Methods: Relative and absolute reliabilities were examined in 14 older people with mild to moderate AD. Relative reliability was calculated using the intraclass correlation coefficient, two-way mixed model (ICC3,1). Absolute reliability was calculated using the standard error of measurement (SEM), the minimum detectable change (MDC) and the coefficient of variation (CV).Results: All measurements were clinically feasible and could be safely administered. ICC values were excellent and CVs were less than 11% in all clinical balance and mobility measures except the Timed Up & Go test with cognitive or manual task (ICC3,1= 0.5 and 0.7, and CV = 14% and 10%, respectively). Most balance and mobility measures tested on the Neurocom™ forceplate (modified Clinical Test of Sensory Interaction on Balance, Walk Across (step width, step length parameters), and Sit to Stand (rising index parameter)) had excellent relative reliability (ICC3,1ranging from 0.75 to 0.91). ICC values were fair to good for the other measures.Conclusions: Retest reliability of the balance and mobility measures used in this study ranged between fair to good, and good to excellent. Clinicians should consider retest reliability when deciding which balance and mobility measures are used to assess people with AD.

A new visual feedback-based system for the assessment of pinch force, endurance, accuracy and precision. A test-retest reliability study

Hand Therapy ◽  
2021 ◽  
pp. 175899832110025
Author(s):  
Alberto Dottor ◽  
Eleonora Camerone ◽  
Mirko Job ◽  
Diletta Barbiani ◽  
Elisa Frisaldi ◽  
...  
Keyword(s):  
Visual Feedback ◽  
Intraclass Correlation ◽  
Precision Grip ◽  
Voluntary Contraction ◽  
Good Reliability ◽  
Retest Reliability ◽  
Relative Reliability ◽  
Time Accuracy ◽  
In The Beginning ◽  
Test Retest Reliability

Introduction Given that pinch is a precision grip involved in sustained submaximal activities, a Sustained Contraction (SC) task could be associated to Maximal Voluntary Contraction (MVC). To better evaluate the thumb-index system, the test-retest reliability of pinch MVC and SC, measured by a visual feedback-based pinch gauge was assessed. Methods 26 healthy participants performed MVC and SC in two separate sessions. SC required to maintain 40%MVC as long as possible and it was evaluated in terms of time, accuracy (Mean Distance between force trace and target force, MD), precision (Coefficient of Variability of force trace, CV). MD and CV analyses were conducted dividing the SC task into three equivalent time stages (beginning, middle, exhaustion). Relative Reliability (RR) was measured by Intraclass Correlation Coefficient, and Absolute Reliability (AR) was measured by Standard Error of Measurement and by Bland-Altman plot. Results MVC and Time showed high RR and AR in both hands. RR of MD and CV in right hand was excellent in the beginning and middle stages, and fair in the exhaustion one, showing decreasing reliability as fatigue increases. In the left hand RR of MD and CV was generally lower. MD showed excellent reliability in the beginning stage and good reliability in the other stages. CV showed fair relative reliability at both beginning and middle stages, excellent in the last one. Conversely, it was observed high AR of MD and CV in all stages in both hands. Conclusions All indices are reliable to assess motor control of thumb-index pinch in both hands.

scholarly journals Assessing the Progression of Alzheimer’s Disease in Real-World Settings in Three European Countries

2021 ◽  
Vol 80 (2) ◽  
pp. 749-759
Author(s):  
Albert Lladó ◽  
Lutz Froelich ◽  
Rezaul K. Khandker ◽  
Montserrat Roset ◽  
Christopher M. Black ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mixed Model ◽  
Primary Objective ◽  
Community Dwelling ◽  
Behavioral Changes ◽  
The Uk ◽  
State Examination ◽  
Study Inclusion

Background: There exists considerable variation in disease progression rates among patients with Alzheimer’s disease (AD). Objective: The primary objective of this observational study is to assess the progression of AD by characterizing cognitive, functional, and behavioral changes during the follow-up period between 6 and 24 months. Methods: A longitudinal prospective study with community-dwelling patients with an established clinical diagnosis of AD of mild to moderate severity was conducted in Germany, Spain and the UK. A sample of 616 patients from 69 sites was included. Results: Patients had a mean of 1.9 years (SD = 1.9) since AD diagnosis at study inclusion. Cognitive symptoms were reported to have first occurred a mean of 1.1 years (SD = 1.7) prior to AD diagnosis and 1.4 (SD = 1.8) years prior to AD treatment. Patients initially diagnosed with mild and moderate AD spent a median (95%CI) of 3.7 (2.8; 4.4) and 11.1 (6.1, ‘not reached’) years until progression to moderate and severe AD, respectively, according to the Mini-Mental State Examination (MMSE) scores. A mixed model developed for cognitive, functional, and neuropsychiatric scores, obtained from study patients at baseline and during follow-up period, showed progressive deterioration of AD patients over time. Conclusion: The study showed a deterioration of cognitive, functional, and neuropsychiatric functions during the follow-up period. Cognitive deterioration was slightly faster in patients with moderate AD compared to mild AD. The duration of moderate AD can be overestimated due to the use of retrospective data, lack of availability of MMSE scores in clinical charts and exclusion of patients at time of institutionalization.

scholarly journals Pre-Analytical and Within-Person Reproducibility of Nutritional Metabolomics over 2 Years in Elders at Risk for Dementia (P18-121-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Gene Bowman ◽  
Natalia Gouskova ◽  
Hiroko Dodge ◽  
Juliana Donohue ◽  
Aline Bichsel ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Measurement Errors ◽  
Brain Aging ◽  
Intraclass Correlation ◽  
Aging Research ◽  
Blood Samples ◽  
Time Points ◽  
Nutritional Metabolomics ◽  
Over Time

Abstract Objectives Nutritional metabolomics to objectively assess dietary intake in aging permit the opportunity to circumvent measurement errors that accompany subjective means of dietary assessment. At the same time, they may offer insights into mechanisms of action and metabolic disturbances that are actionable targets for modulation through diet in hopes of disease prevention and treatment. However, prior to more broad deployment the pre-analytical and temporal variation over time should be documented in order to design and interpret epidemiological studies properly. We quantified and examined 155 nutrient biomarkers and metabolites selected for their potential relevance to dementia. Methods Blood samples from three time points, spanning a 2-year period, were obtained from older adults participating in the NIA-Layton Oregon Alzheimer's Disease Center's Nutrition and Brain Aging Study (NBAS). Blood samples were batched randomly across three time points for quantification of blood amino acids, minerals, water and fat-soluble micronutrients, lipids, one carbon, and kynurenine pathway metabolites using a variety of methods including, tandem mass spectrometry. Pre-analytical coefficients of variation (CV) were calculated for all the biomarkers and intraclass correlation coefficients (ICC) were calculated to evaluate the within-person reproducibility in a subset of 137 participants. Results The mean baseline age of the analytic sample (n = 137) was 85.6 (± 8.3, 57 - 101 years), 70% are female, 21% carry the ApoEe4 allele and MMSE was 28.3 (± 1.78). The pre-analytical CVs ranged from 0.9% to 55.0% and the ICC ranged from 0 to 0.87 (25%-tile/median/75%-tile 0.41/0.54/0.66). Twenty four % had ICC < 0.40, 66% had ICC 0.40 −0.75 and 10% had ICC > 0.75. Conclusions The pre-analytical and within-person reproducibility of nutritional metabolomics in aging ranges widely. The majority can reliably estimate average concentrations over a 2 year period from a single time point and the biomarkers with ICC's above 0.40 can be used for correction of measurement error and those below 0.40 should consider multiple samples per subject and exploring the methodological and biological explanation for the variation over time. Funding Sources Nestle Institute of Health Sciences, Hinda and Arthur Marcus Institute for Aging Research, NIA-Layton Aging & Alzheimer's Disease Center (P30AGO8017).

scholarly journals Antidiabetic Polypill Improves Central Pathology and Cognitive Impairment in a Mixed Model of Alzheimer’s Disease and Type 2 Diabetes

2017 ◽  
Vol 55 (7) ◽  
pp. 6130-6144 ◽  
Author(s):  
Carmen Infante-Garcia ◽  
Juan Jose Ramos-Rodriguez ◽  
Carmen Hierro-Bujalance ◽  
Esperanza Ortegon ◽  
Eleanor Pickett ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Type 2 Diabetes ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mixed Model ◽  
Model Of Alzheimer’S Disease ◽  
Central Pathology

scholarly journals Assessment of neurovascular coupling and cortical spreading depression in mixed mouse models of atherosclerosis and Alzheimer’s disease

eLife ◽  
2022 ◽  
Vol 11 ◽  
Author(s):  
Osman Shabir ◽  
Ben Pendry ◽  
Llywelyn Lee ◽  
Beth Eyre ◽  
Paul S Sharp ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cortical Spreading Depression ◽  
Mixed Model ◽  
Spreading Depression ◽  
Neurovascular Coupling ◽  
Cardiovascular Comorbidities ◽  
Neurological Conditions ◽  
Electrode Insertion ◽  
The Brain

Neurovascular coupling is a critical brain mechanism whereby changes to blood flow accompany localised neural activity. The breakdown of neurovascular coupling is linked to the development and progression of several neurological conditions including dementia. In this study, we examined cortical haemodynamics in mouse preparations that modelled Alzheimer’s disease (J20-AD) and atherosclerosis (PCSK9-ATH) between 9 and 12 m of age. We report novel findings with atherosclerosis where neurovascular decline is characterised by significantly reduced blood volume, altered levels of oxyhaemoglobin and deoxyhaemoglobin, in addition to global neuroinflammation. In the comorbid mixed model (J20-PCSK9-MIX), we report a 3 x increase in hippocampal amyloid-beta plaques. A key finding was that cortical spreading depression (CSD) due to electrode insertion into the brain was worse in the diseased animals and led to a prolonged period of hypoxia. These findings suggest that systemic atherosclerosis can be detrimental to neurovascular health and that having cardiovascular comorbidities can exacerbate pre-existing Alzheimer’s-related amyloid-plaques.

Cognitive Performance Test: A New Approach to Functional Assessment in Alzheimer's Disease

1994 ◽  
Vol 7 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Theressa Burns ◽  
James A. Mortimer ◽  
Peggy Merchak
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Activities Of Daily Living ◽  
Cognitive Performance ◽  
Daily Living ◽  
Performance Test ◽  
Intraclass Correlation ◽  
Assessment Instrument ◽  
Cognitive Disability ◽  
Performance Based Assessment

A new performance-based assessment instrument for evaluating function in patients with Alzheimer's disease (AD), the Cognitive Performance Test (CPT), is described. This instrument, based on Allen Cognitive Disability Theory, uses six common activities of daily living (ADL) tasks, for which the information-processing requirements can be systematically varied to assess ordinal levels of functional capacity. Seventy-seven patients with mild to moderate Alzheimer's disease (AD) and 15 neurologically normal elderly controls were administered the CPT. Subsets of the AD patients were assessed again at 4 weeks and 1, 2, and 3 years following the initial evaluation. Internal consistency of the CPT estimated by α was .84. Intraclass correlation for interrater reliability was .91 and for test-retest reliability at 4 weeks, .89. CPT scores were significantly correlated with Mini-Mental State Examination scores (r = .67) and two measures of caregiver-rated ADL (Instrumental Activities of Daily Living, r = .64; Physical Self-Maintenance Scale, r = .49). Significant declines in CPT scores were seen on 1-, 2-, and 3-year follow-ups. Initial CPT scores predicted risk of institutionalization over a 4-year follow-up period.

Psychometric Properties of the Family Stigma in Alzheimer's Disease Scale in Greek Professional Caregivers

2020 ◽  
Vol 28 (2) ◽  
pp. 259-282
Author(s):  
Marianna Mantzorou ◽  
Sofia Zyga ◽  
Dimos Mastrogiannis ◽  
Evmorfia Koukia
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Principal Component ◽  
Maslach Burnout Inventory ◽  
Validity And Reliability ◽  
Retest Reliability ◽  
People With Dementia ◽  
The Family ◽  
High Internal Consistency ◽  
Test Retest Reliability

Background and PurposesThe present study was undertaken in order to evaluate the validity and reliability of the Family Stigma in Alzheimer's Disease Scale (FS-ADS) in the Greek population.MethodsThe Greek version of the FS-ADS as well as the Maslach Burnout Inventory (MBI) was administered to 171 healthcare professional caring for people with dementia. Exploratory factor analysis was performed to examine the factor structure of the FS-ADS. Test–retest reliability was measured by administration of the FS-ADS in 20 individuals.ResultsPrincipal component analysis revealed 5, 8 and 3 factors (subscales) for each dimension of the original questionnaire, respectively, similar to other previously reported results in the literature. The overall Cronbach's α was .899, yielding a high internal consistency. Test–retest reliability was very high (r = 0.903, p < .001). Statistically significant relationships were found between most of the FS-ADS dimensions and Maslach subscales.ConclusionThe findings favor the use of FS-ADS in nurses and professional caregivers in general, for measuring stigma in dementia in Greece.

scholarly journals Quantification of [18F]florbetapir: A test–retest tracer kinetic modelling study

2018 ◽  
Vol 39 (11) ◽  
pp. 2172-2180 ◽  
Author(s):  
Sandeep SV Golla ◽  
Sander CJ Verfaillie ◽  
Ronald Boellaard ◽  
Sofie M Adriaanse ◽  
Marissa D Zwan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
Volume Ratio ◽  
Distribution Volume ◽  
Emission Tomography ◽  
Retest Reliability ◽  
Positron Emission ◽  
Distribution Volume Ratio ◽  
Test Retest Reliability

Accumulation of amyloid beta can be visualized using [18F]florbetapir positron emission tomography. The aim of this study was to identify the optimal model for quantifying [18F]florbetapir uptake and to assess test–retest reliability of corresponding outcome measures. Eight Alzheimer’s disease patients (age: 67 ± 6 years, Mini-Mental State Examination (MMSE): 23 ± 3) and eight controls (age: 63 ± 4 years, MMSE: 30 ± 0) were included. Ninety-minute dynamic positron emission tomography scans, together with arterial blood sampling, were acquired immediately following a bolus injection of 294 ± 32 MBq [18F]florbetapir. Several plasma input models and the simplified reference tissue model (SRTM) were evaluated. The Akaike information criterion was used to identify the preferred kinetic model. Compared to controls, Alzheimer’s disease patients had lower MMSE scores and evidence for cortical Aβ pathology. A reversible two-tissue compartment model with fitted blood volume fraction (2T4k_VB) was the preferred model for describing [18F]florbetapir kinetics. SRTM-derived non-displaceable binding potential (BPND) correlated well (r2 = 0.83, slope = 0.86) with plasma input-derived distribution volume ratio. Test–retest reliability for plasma input-derived distribution volume ratio, SRTM-derived BPND and SUVr(50–70) were r = 0.88, r = 0.91 and r = 0.86, respectively. In vivo kinetics of [18F]florbetapir could best be described by a reversible two-tissue compartmental model and [18F]florbetapir BPND can be reliably estimated using an SRTM.

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