Critical appraisal of questionnaires to assess functional impairment in individuals with mild cognitive impairment

Assessing the cognitive decline of people in the spectrum of AD by monitoring their activities of daily living in an IoT-enabled smart home environment: a cross-sectional pilot study

Introduction

Assessing functional decline related to activities of daily living (ADLs) is deemed significant for the early diagnosis of dementia. As current assessment methods for ADLs often lack the ability to capture subtle changes, technology-based approaches are perceived as advantageous. Specifically, digital biomarkers are emerging, offering a promising avenue for research, as they allow unobtrusive and objective monitoring.

Methods

A study was conducted with the involvement of 36 participants assigned to three known groups (Healthy Controls, participants with Subjective Cognitive Decline and participants with Mild Cognitive Impairment). Participants visited the CERTH-IT Smart Home, an environment that simulates a fully functional residence, and were asked to follow a protocol describing different ADL Tasks (namely Task 1 - Meal, Task 2 - Beverage and Task 3 - Snack Preparation). By utilizing data from fixed in-home sensors installed in the Smart Home, the identification of the performed Tasks and their derived features was explored through the developed CARL platform. Furthermore, differences between groups were investigated. Finally, overall feasibility and study satisfaction were evaluated.

Results

The composition of the ADLs was attainable, and differentiation among the HC group compared to the SCD and the MCI groups considering the feature "Activity Duration" in Task 1 - Meal Preparation was possible, while no difference could be noted between the SCD and the MCI groups.

Discussion

This ecologically valid study was determined as feasible, with participants expressing positive feedback. The findings additionally reinforce the interest and need to include people in preclinical stages of dementia in research to further evolve and develop clinically relevant digital biomarkers.

Speech Acts as a Window to the Difficulties in Instrumental Activities of Daily Living: A Qualitative Descriptive Study in Mild Neurocognitive Disorder and Healthy Aging

Background

Executive functions (EF) are central to instrumental activities of daily living (IADL). A novel approach to the assessment of the impact of EF difficulties on IADL may be through the speech acts produced when performing IADL-inspired tasks in a laboratory-apartment. Speech acts may act as a window to the difficulties encountered during task performance.

Objective

We aim to 1) qualitatively describe the speech acts produced by participants with mild neurocognitive disorder (mild NCD) and healthy controls (HC) as they performed 4 IADL-inspired tasks in a laboratory-apartment, and to then 2) compare their use in both groups.

Methods

The participants' performance was videotaped, and speech acts produced were transcribed. Qualitative description of all speech acts was performed, followed by a deductive-inductive pattern coding of data. Statistical analyses were performed to further compare their use by mild NCD participants and HC.

Results

Twenty-two participants took part in the study (n mild NCD = 11; n HC = 11). Meta-categories of data emerged from pattern coding: strategies, barriers, reactions, and consequences. Mild NCD participants used significantly more strategies and barriers than did HC. They were more defensive of their performance, and more reactive to their difficulties than HC. Mild NCD participants' verification of having completed all tasks was less efficient than controls.

Conclusions

An assessment of speech acts produced during the performance of IADL-inspired tasks in a laboratory-apartment may allow to detect changes in the use of language which may reflect EF difficulties linked to cognitive decline.

Digital endpoints in clinical trials of Alzheimer's disease and other neurodegenerative diseases: challenges and opportunities

Alzheimer's disease (AD) and other neurodegenerative diseases such as Parkinson's disease (PD) and Huntington's disease (HD) are associated with progressive cognitive, motor, affective and consequently functional decline considerably affecting Activities of Daily Living (ADL) and quality of life. Standard assessments, such as questionnaires and interviews, cognitive testing, and mobility assessments, lack sensitivity, especially in early stages of neurodegenerative diseases and in the disease progression, and have therefore a limited utility as outcome measurements in clinical trials. Major advances in the last decade in digital technologies have opened a window of opportunity to introduce digital endpoints into clinical trials that can reform the assessment and tracking of neurodegenerative symptoms. The Innovative Health Initiative (IMI)-funded projects RADAR-AD (Remote assessment of disease and relapse-Alzheimer's disease), IDEA-FAST (Identifying digital endpoints to assess fatigue, sleep and ADL in neurodegenerative disorders and immune-mediated inflammatory diseases) and Mobilise-D (Connecting digital mobility assessment to clinical outcomes for regulatory and clinical endorsement) aim to identify digital endpoints relevant for neurodegenerative diseases that provide reliable, objective, and sensitive evaluation of disability and health-related quality of life. In this article, we will draw from the findings and experiences of the different IMI projects in discussing (1) the value of remote technologies to assess neurodegenerative diseases; (2) feasibility, acceptability and usability of digital assessments; (3) challenges related to the use of digital tools; (4) public involvement and the implementation of patient advisory boards; (5) regulatory learnings; and (6) the significance of inter-project exchange and data- and algorithm-sharing.

The Cognitive Scale of Basic and Instrumental Activities of Daily Living for Multidomain Mild Cognitive Impairment and Dementia Patients: Validation of its Extended Version

OBJECTIVE

To validate an informant-based tool - the extended version of the Cognitive Scale of Basic and Instrumental Activities of Daily Living (BADL and IADL) or Ext. Cog-ADL Scale - in a larger sample and with a broader range of cognitive-functional items related to activities of daily living (ADL).

METHOD

The Ext. Cog-ADL Scale was administered to family informants of 42 patients with dementia, 43 patients with multidomain mild cognitive impairment (mdMCI), and 23 healthy control participants. We analyzed the convergent and concurrent validity and external validity of this scale.

RESULTS

The Ext. Cog-ADL Scale demonstrated good psychometric properties. Episodic and working memory tests were the main predictors of most cognitive-functional items of the scale. While patients with dementia obtained lower scores in most error categories of the scale, affecting both BADL and IADL, mdMCI patients showed a more specific pattern of difficulties. Apart from the typical alterations in IADL, mdMCI patients also showed difficulties in several error categories related to BADL (i.e., error detection, problem solving, task self-initiation, distraction inhibition, and restore).

CONCLUSIONS

The Ext. Cog-ADL Scale seems to be an adequate tool to capture the specific pattern of cognitive alterations related to IADL and BADL that differentiates dementia from mdMCI and healthy aging; it shows that mdMCI can involve specific cognitive difficulties that affect even BADL.

Systematic review of reviews on Activities of Daily Living measures for children with developmental disabilities

Background

There seems to be a lack of consensus on the concept and domains of Activities of Daily Living (ADL) measured among children and adolescents with developmental disabilities (DD), despite a significant number of existing measures of ADL and associated constructs, and two prevailing theoretical frameworks (i.e., the cognitive-social-practical framework, and the activity-and-participation framework).

Aims

This systematic review (SR) aims to identify articles that systematically reviewed measures of ADL for children and adolescents aged 7-18 years with DD to evaluate the quality of included articles, and describe the measures and domains identified.

Methods

and Procedures: Searches were conducted in PubMed®, Academic Search Complete® (EBSCOhost), Education Source Search® (EBSCOhost), ERIC® (EBSCOhost), and PsychInfo® (EBSCOhost). 14,931 articles were identified, and two researchers completed title screening, abstract screening, and full-text screening, with disagreements resolved. Out of these 14,931 articles, fourteen were included, which resulted in a total of 163 ADL measures. Out of the 163 ADL measures, forty-eight met the criteria and were included for analysis. PRISMA and COSMIN checklists were used to appraise the methodological quality of the included articles.

Outcomes and results

Results indicated that most of the 14 systematic review articles did not provide information on instrument development and content validity of their included measures. Analysis of the identified 48 measures of ADL and its associated constructs revealed heterogeneity in domains covered, although there were seven domains that were most often included.

Conclusions and implications

Implications in terms of practice, research, and policy are further discussed.

Machine learning identifies novel markers predicting functional decline in older adults

The ability to carry out instrumental activities of daily living, such as paying bills, remembering appointments and shopping alone decreases with age, yet there are remarkable individual differences in the rate of decline among older adults. Understanding variables associated with a decline in instrumental activities of daily living is critical to providing appropriate intervention to prolong independence. Prior research suggests that cognitive measures, neuroimaging and fluid-based biomarkers predict functional decline. However, a priori selection of variables can lead to the over-valuation of certain variables and exclusion of others that may be predictive. In this study, we used machine learning techniques to select a wide range of baseline variables that best predicted functional decline in two years in individuals from the Alzheimer's Disease Neuroimaging Initiative dataset. The sample included 398 individuals characterized as cognitively normal or mild cognitive impairment. Support vector machine classification algorithms were used to identify the most predictive modality from five different data modality types (demographics, structural MRI, fluorodeoxyglucose-PET, neurocognitive and genetic/fluid-based biomarkers). In addition, variable selection identified individual variables across all modalities that best predicted functional decline in a testing sample. Of the five modalities examined, neurocognitive measures demonstrated the best accuracy in predicting functional decline (accuracy = 74.2%; area under the curve = 0.77), followed by fluorodeoxyglucose-PET (accuracy = 70.8%; area under the curve = 0.66). The individual variables with the greatest discriminatory ability for predicting functional decline included partner report of language in the Everyday Cognition questionnaire, the ADAS13, and activity of the left angular gyrus using fluorodeoxyglucose-PET. These three variables collectively explained 32% of the total variance in functional decline. Taken together, the machine learning model identified novel biomarkers that may be involved in the processing, retrieval, and conceptual integration of semantic information and which predict functional decline two years after assessment. These findings may be used to explore the clinical utility of the Everyday Cognition as a non-invasive, cost and time effective tool to predict future functional decline.

Quantifying activities of daily living impairment in Parkinson's disease using the Functional Activities Questionnaire

OBJECTIVE

Cognitive-driven activity of daily living (ADL) impairment in Parkinson's disease (PD) is increasingly discussed as prodromal marker for dementia. Diagnostic properties of assessments for this specific ADL impairment are sparsely investigated in PD. The ability of the Functional Activities Questionnaire (FAQ) for differentiating between PD patients with normal cognition and with mild cognitive impairment (PD-MCI), according to informant and self-reports, was examined. Global cognitive function in groups with and without mild ADL impairment was compared according to different cut-offs.

METHODS

Multicenter data of 589 patients of an international cohort (CENTRE-PD) were analyzed. Analyses were run separately for informant-rated and self-rated FAQ. Receiver operating characteristic (ROC) analysis was conducted to define the optimal FAQ cut-off for PD-MCI (≥ 1), and groups were additionally split according to reported FAQ cut-offs for PD-MCI in the literature (≥ 3, ≥ 5). Binary logistic regressions examined the effect of the Montreal Cognitive Assessment (MoCA) score in PD patients with and without mild ADL impairment.

RESULTS

Two hundred and twenty-five (38.2%) patients were classified as PD-MCI. For all three cut-off values, sensitivity was moderate to low (< 0.55), but specificity was moderately high (> 0.54) with a tendency of higher values for self-reported deficits. For the self-report, the cut-off ≥ 3 showed a significant effect of the MoCA (B =  - 0.31, p = 0.003), where FAQ ≥ 3 patients had worse cognition. No effect for group differences based on informant ratings was detected.

CONCLUSION

Our data argue that self-reported ADL impairments assessed by the FAQ show a relation to the severity of cognitive impairment in PD.

Predementia constructs: Mild cognitive impairment or mild neurocognitive disorder? A narrative review

BACKGROUND

Predementia is a heuristic umbrella concept to classify older adults with cognitive impairment who do not suffer dementia. Many diagnostic entities have been proposed to address this concept, but most of them have not had widespread acceptance.

AIMS

To review clinical definitions, epidemiologic data (prevalence, incidence) and rate of conversion to dementia of the main predementia constructs, with special interest in the two most frequently used: mild cognitive impairment (MCI) and minor neurocognitive disorder (miNCD).

METHODS

We have selected in three databases (MEDLINE, Web of Science and Google scholar) the references from inception to 31 December 2019 of relevant reviews, population and community-based surveys, and clinical series with >500 participants and >3 years follow-up as the best source of evidence.

MAIN RESULTS

The history of predementia constructs shows that MCI is the most referred entity. It is widely recognized as a clinical syndrome harbinger of dementia of several etiologies, mainly MCI due to Alzheimer's disease. The operational definition of MCI has shortcomings: vagueness of its requirement of "preserved independence in functional abilities" and others. The recent miNCD construct presents analogous difficulties. Current data indicate that it is a stricter predementia condition, with lower prevalence than MCI, less sensitivity to cognitive decline and, possibly, higher conversion rate to dementia.

CONCLUSIONS

MCI is a widely employed research and clinical entity. Preliminary data indicate that the clinical use of miNCD instead of MCI requires more scientific evidence. Both approaches have common limitations that need to be addressed.

Cross-cultural adaptation and validation of the Amsterdam Instrumental Activities of Daily Living questionnaire short version German for Switzerland

Background

Instrumental Activities of Daily Living (IADL) limitations are associated with reduced health-related quality of life for people with mild cognitive impairment (MCI). For these people, the assessment of IADL is crucial to the diagnostic process, as well as for the evaluation of new interventions addressing MCI. The Amsterdam IADL Questionnaire Short Version (A-IADL-Q-SV) is an established assessment tool with good psychometric properties that has been shown to be robust to cultural differences in Western countries. The aims of this study were to: (1) cross-culturally adapt and validate the A-IADL-Q-SV for the German-speaking population of Switzerland; (2) investigate its cultural comparability; and (3) evaluate further psychometric properties.

Methods

The A-IADL-Q-SV German was pretested on clinicians and participants in a memory clinic setting. The psychometric properties and cultural comparability of the questionnaire were investigated in memory clinic settings including participants with MCI or mild dementia, as well as participants with normal cognition recruited from the community. Item response theory (IRT) was applied to investigate measurement invariance by means of differential item functioning to assess item bias. Additionally, the test–retest reliability on scale level, the construct validity through hypothesis testing and the discriminant validity of the A-IADL-Q-SV German were evaluated.

Results

Ninety-six informants of participants with normal cognition, MCI or mild dementia completed the A-IADL-Q-SV German. The basic assumptions for IRT scoring were met. No meaningful differential item functioning for culture was detected between the Swiss and Dutch reference samples. High test–retest reliability on scale level (ICC 0.93; 95% CI 0.9–0.96) was found. More than 75% of the observed correlations between the A-IADL-Q-SV German and clinical measures of cognition and functional status were found to be in the direction and of the magnitude hypothesized. The A-IADL-Q-SV German was shown to be able to discriminate between participants with normal cognition and MCI, as well as MCI and mild dementia.

Conclusions

The A-IADL-Q-SV German is a psychometrically robust measurement tool for a Swiss population with normal cognition, MCI and mild dementia. Thus, it provides a valuable tool to assess IADL functioning in clinical practices and research settings in Switzerland.

Trial registration This study was registered retrospectively in July 2019 on ClinicalTrials.gov (NCT04012398).

The Cognitive-Functional Composite is sensitive to clinical progression in early dementia: Longitudinal findings from the Catch-Cog study cohort

INTRODUCTION

In an attempt to capture clinically meaningful cognitive decline in early dementia, we developed the Cognitive-Functional Composite (CFC). We investigated the CFC's sensitivity to decline in comparison to traditional clinical endpoints.

METHODS

This longitudinal construct validation study included 148 participants with subjective cognitive decline, mild cognitive impairment, or mild dementia. The CFC and traditional tests were administered at baseline, 3, 6, and 12 months. Sensitivity to change was investigated using linear mixed models and r 2 effect sizes.

RESULTS

CFC scores declined over time (β = -.16, P < .001), with steepest decline observed in mild Alzheimer's dementia (β = -.25, P < .001). The CFC showed medium-to-large effect sizes at succeeding follow-up points (r 2 = .08-.42), exhibiting greater change than the Clinical Dementia Rating scale (r 2 = .02-.12). Moreover, change on the CFC was significantly associated with informant reports of cognitive decline (β = .38, P < .001).

DISCUSSION

By showing sensitivity to decline, the CFC could enhance the monitoring of disease progression in dementia research and clinical practice.

Beta-amyloid (Aβ) uptake by PET imaging in older HIV+ and HIV- individuals

The causes of cognitive impairment among older HIV+ individuals may overlap with causes among elderly HIV seronegative (HIV-) individuals. The objective of this study was to determine if beta-amyloid (Aβ) deposition measured by [¹⁸F] AV-45 (florbetapir) positron emission tomography (PET) is increased in older HIV+ individuals compared to HIV- individuals. Forty-eight HIV+ and 25 HIV- individuals underwent [¹⁸F] AV-45 PET imaging. [¹⁸F] AV-45 binding to Aβ was measured by standardized uptake value ratios (SUVR) relative to the cerebellum in 16 cortical and subcortical regions of interest. Global and regional cortical SUVRs were compared by (1) serostatus, (2) HAND stage, and (3) age decade, comparing individuals in their 50s and > 60s. There were no differences in median global cortical SUVR stratified by HIV serostatus or HAND stage. The proportion of HIV+ participants in their 50s with elevated global amyloid uptake (SUVR > 1.40) was significantly higher than the proportion in HIV- participants (67% versus 25%, p = 0.04), and selected regional SUVR values were also higher (p < 0.05) in HIV+ compared to HIV- participants in their 50s. However, these group differences were not seen in participants in their 60s. In conclusion, PET imaging found no differences in overall global Aβ deposition stratified by HIV serostatus or HAND stage. Although there was some evidence of increased Aβ deposition in HIV+ individuals in their 50s compared to HIV- individuals which might indicate premature aging, the most parsimonious explanation for this is the relatively small sample size in this cross-sectional cohort study.

The Association between the Montreal Cognitive Assessment and Functional Activity Questionnaire in the Systolic Blood Pressure Intervention Trial (SPRINT)

OBJECTIVE

To examine the association of global cognitive function assessed via the Montreal Cognitive Assessment (MoCA) and deficiencies in instrumental activities of daily living (IADL) on the Functional Activity Questionnaire (FAQ) in hypertensive older adults in the Systolic Blood Pressure Intervention Trial (SPRINT).

METHODS

In cross-sectional analysis, 9,296 SPRINT participants completed the MoCA at baseline. The FAQ was obtained from 2,705 informants for SPRINT participants scoring <21 or <22 on the MoCA, depending on education. FAQ severity ranged from no dysfunction (Score = 0) to moderate/severe dysfunction (Score = 5+).

RESULTS

Participants who triggered FAQ administration were older, less educated, and more likely to be Black or Hispanic (p < 0.001). Sixty-one percent (n = 1,661) of participants' informants reported no functional difficulties in IADLs. An informant report, however, of any difficulty on the FAQ was associated with lower MoCA scores after controlling for age, sex, race/ethnicity, and education (p < 0.05). Partial proportional odds regression indicates that participants scoring lower on the MoCA (in the 10th to <25th, fifth to <10th, and <fifth percentiles) had higher adjusted odds of their informant indicating dysfunction on the FAQ, relative to participants scoring at or above the 25th percentile on the MoCA (p < 0.001).

CONCLUSIONS

While lower global cognitive function was strongly associated with IADL deficits on FAQ, informants indicated no functional difficulties for the majority of SPRINT participants, despite low MoCA scores. These findings can help with designing future studies which aim to detect mild cognitive impairment and/or dementia in large, community-dwelling populations.

Altered Directed Functional Connectivity of the Hippocampus in Mild Cognitive Impairment and Alzheimer's Disease: A Resting-State fMRI Study

The hippocampus is generally reported as one of the regions most impacted by Alzheimer's disease (AD) and is closely associated with memory function and orientation. Undirected functional connectivity (FC) alterations occur in patients with mild cognitive impairment (MCI) and AD, and these alterations have been the subject of many studies. However, abnormal patterns of directed FC remain poorly understood. In this study, to identify changes in directed FC between the hippocampus and other brain regions, Granger causality analysis (GCA) based on voxels was applied to resting-state functional magnetic resonance imaging (rs-fMRI) data from 29 AD, 65 MCI, and 30 normal control (NC) subjects. The results showed significant differences in the patterns of directed FC among the three groups. There were fewer brain regions showing changes in directed FC with the hippocampus in the MCI group than the NC group, and these regions were mainly located in the temporal lobe, frontal lobe, and cingulate cortex. However, regarding the abnormalities in directed FC in the AD group, the number of affected voxels was greater, the size of the clusters was larger, and the distribution was wider. Most of the abnormal connections were unidirectional and showed hemispheric asymmetry. In addition, we also investigated the correlations between the abnormal directional FCs and cognitive and clinical measurement scores in the three groups and found that some of them were significantly correlated. This study revealed abnormalities in the transmission and reception of information in the hippocampus of MCI and AD patients and offer insight into the neurophysiological mechanisms underlying MCI and AD.

Overview of reviews of standardised occupation-based instruments for use in occupational therapy practice

INTRODUCTION

Using standardised instruments is one approach to support evidence-based practice. Referring to systematic reviews is an option to identify suitable instruments. However, with an abundance of systematic reviews available, therapists are challenged to identify an appropriate instrument to use. Therefore, this overview of reviews aimed to summarise relevant systematic review findings about standardised occupation-based instruments relevant for occupational therapy practice.

METHODS

An overview of reviews was conducted. A systematic search was performed on four databases up to March 2018. Included systematic reviews were analysed for quality using A MeaSurement Tool to Assess systematic Reviews (AMSTAR).

RESULTS

A total of 2187 articles were identified after removing duplicates. Ultimately, 58 systematic reviews were identified that yielded 641 instruments. From those, 45 instruments were selected for appraisal as they met the inclusion criteria of being developed mainly by occupational therapists and were recommended in the summarised findings from the systematic reviews. The instruments were classified according to the following occupation domains: (i) multidimensional, (ii) activities of daily living, (iii) productivity, (iv) social, (v) sleep/rest, (vi) sexuality and (vii) spirituality. No systematic review was identified that specifically focussed on occupations related to school/education, leisure and play.

DISCUSSION

Certain occupation domains such as activities of daily living, social and sleep/rest received high attention amongst researchers. There is a need for systematic reviews of instruments to measure education/school, play and leisure. Limited numbers of instruments were developed by occupational therapists outside the occupation domain of activities of daily living, and in areas of practice other than children and older people. Nevertheless, this overview can give some guidance for occupational therapists in selecting a suitable occupational therapy instrument for practice.

The Multidisciplinary Approach to Alzheimer's Disease and Dementia. A Narrative Review of Non-Pharmacological Treatment

Background: Alzheimer's disease (AD) and dementia are chronic diseases with progressive deterioration of cognition, function, and behavior leading to severe disability and death. The prevalence of AD and dementia is constantly increasing because of the progressive aging of the population. These conditions represent a considerable challenge to patients, their family and caregivers, and the health system, because of the considerable need for resources allocation. There is no disease modifying intervention for AD and dementia, and the symptomatic pharmacological treatments has limited efficacy and considerable side effects. Non-pharmacological treatment (NPT), which includes a wide range of approaches and techniques, may play a role in the treatment of AD and dementia. Aim: To review, with a narrative approach, current evidence on main NPTs for AD and dementia. Methods: PubMed and the Cochrane database of systematic reviews were searched for studies written in English and published from 2000 to 2018. The bibliography of the main articles was checked to detect other relevant papers. Results: The role of NPT has been largely explored in AD and dementia. The main NPT types, which were reviewed here, include exercise and motor rehabilitation, cognitive rehabilitation, NPT for behavioral and psychological symptoms of dementia, occupational therapy, psychological therapy, complementary and alternative medicine, and new technologies, including information and communication technologies, assistive technology and domotics, virtual reality, gaming, and telemedicine. We also summarized the role of NPT to address caregivers' burden. Conclusions: Although NPT is often applied in the multidisciplinary approach to AD and dementia, supporting evidence for their use is still preliminary. Some studies showed statistically significant effect of NPT on some outcomes, but their clinical significance is uncertain. Well-designed randomized controlled trials with innovative designs are needed to explore the efficacy of NPT in AD and dementia. Further studies are required to offer robust neurobiological grounds for the effect of NPT, and to examine its cost-efficacy profile in patients with dementia.

Dynamic Complexity of Spontaneous BOLD Activity in Alzheimer's Disease and Mild Cognitive Impairment Using Multiscale Entropy Analysis

Alzheimer's disease (AD) is characterized by progressive deterioration of brain function among elderly people. Studies revealed aberrant correlations in spontaneous blood oxygen level-dependent (BOLD) signals in resting-state functional magnetic resonance imaging (rs-fMRI) over a wide range of temporal scales. However, the study of the temporal dynamics of BOLD signals in subjects with AD and mild cognitive impairment (MCI) remains largely unexplored. Multiscale entropy (MSE) analysis is a method for estimating the complexity of finite time series over multiple time scales. In this research, we applied MSE analysis to investigate the abnormal complexity of BOLD signals using the rs-fMRI data from the Alzheimer's disease neuroimaging initiative (ADNI) database. There were 30 normal controls (NCs), 33 early MCI (EMCI), 32 late MCI (LMCI), and 29 AD patients. Following preprocessing of the BOLD signals, whole-brain MSE maps across six time scales were generated using the Complexity Toolbox. One-way analysis of variance (ANOVA) analysis on the MSE maps of four groups revealed significant differences in the thalamus, insula, lingual gyrus and inferior occipital gyrus, superior frontal gyrus and olfactory cortex, supramarginal gyrus, superior temporal gyrus, and middle temporal gyrus on multiple time scales. Compared with the NC group, MCI and AD patients had significant reductions in the complexity of BOLD signals and AD patients demonstrated lower complexity than that of the MCI subjects. Additionally, the complexity of BOLD signals from the regions of interest (ROIs) was found to be significantly associated with cognitive decline in patient groups on multiple time scales. Consequently, the complexity or MSE of BOLD signals may provide an imaging biomarker of cognitive impairments in MCI and AD.

7T Brain MRS in HIV Infection: Correlation with Cognitive Impairment and Performance on Neuropsychological Tests

BACKGROUND AND PURPOSE

Validated neuroimaging markers of HIV-associated neurocognitive disorder in patients on antiretroviral therapy are urgently needed for clinical trials. The purpose of this study was to explore the relationship between cognitive impairment and brain metabolism in older subjects with HIV infection. It was hypothesized that MR spectroscopy measurements related to neuronal health and function (particularly N-acetylaspartate and glutamate) would be lower in HIV-positive subjects with worse cognitive performance.

MATERIALS AND METHODS

Forty-five HIV-positive patients (mean age, 58.9 ± 5.3 years; 33 men) underwent detailed neuropsychological testing and brain MR spectroscopy at 7T. Twenty-four subjects were classified as having asymptomatic cognitive impairment, and 21 were classified as having symptomatic cognitive impairment. Single-voxel proton MR spectra were acquired from 5 brain regions and quantified using LCModel software. Brain metabolites and neuropsychological test results were compared using nonparametric statistics and Pearson correlation coefficients.

RESULTS

Differences in brain metabolites were found between symptomatic and asymptomatic subjects, with the main findings being lower measures of N-acetylaspartate in the frontal white matter, posterior cingulate cortex, and precuneus. In the precuneus, glutamate was also lower in the symptomatic group. In the frontal white matter, precuneus, and posterior cingulate cortex, NAA and glutamate measurements showed significant positive correlation with better performance on neuropsychological tests.

CONCLUSIONS

Compared with asymptomatic subjects, symptomatic HIV-positive subjects had lower levels of NAA and glutamate, most notably in the frontal white matter, which also correlated with performance on neuropsychological tests. High-field MR spectroscopy offers insight into the pathophysiology associated with cognitive impairment in HIV and may be useful as a quantitative outcome measure in future treatment trials.

A novel cognitive-functional composite measure to detect changes in early Alzheimer's disease: Test-retest reliability and feasibility

Introduction

To improve the detection of changes in Alzheimer's disease (AD), we designed the cognitive-functional composite (CFC). As a first validation step, we investigated its test–retest reliability and feasibility of use.

Methods

We performed a test–retest study with 2–3 weeks between assessments, including patients with mild cognitive impairment (MCI) or mild AD dementia and cognitively healthy participants. We calculated intraclass correlation coefficients (ICCs) type absolute agreement for all CFC measures and compared baseline and retest scores using paired-samples t-tests. We evaluated feasibility by interviewing participants.

Results

Forty-three patients (40% female, mean age = 69.9) and 30 controls (50% female, mean age = 65) were included. Subtest intraclass correlation coefficients ranged from .70 to .96. We found negligible improvements after retesting on only two subtests. Overall, patients perceived the administration of the CFC as feasible.

Discussion

The CFC is a stable and feasible measure in MCI and mild AD dementia, and thereby meets important quality metrics for clinically meaningful outcome measures.

•

We investigated stability and feasibility of the cognitive-functional composite (CFC).

•

We demonstrated good test–retest reliability for all CFC subtests.

•

We only found negligible practice effects on two CFC subtests.

•

Overall, patients experienced the administration of the CFC as feasible.

Detecting functional decline from normal aging to dementia: Development and validation of a short version of the Amsterdam IADL Questionnaire

Introduction

Detecting functional decline from normal aging to dementia is relevant for diagnostic and prognostic purposes. Therefore, the Amsterdam IADL Questionnaire (A-IADL-Q) was developed: a 70-item proxy-based tool with good psychometric properties. We aimed to design a short version while preserving its psychometric quality.

Methods

Study partners of subjects (n = 1355), ranging from cognitively normal to dementia subjects, completed the original A-IADL-Q. We selected the short version items using a stepwise procedure combining missing data, Item Response Theory, and input from respondents and experts. We investigated internal consistency of the short version and concordance with the original version. To assess its construct validity, we additionally investigated concordance between the short version and the Mini–Mental State Examination (MMSE) and Disability Assessment for Dementia (DAD). Finally, we investigated differences in instrumental activities of daily living (IADL) scores between diagnostic groups across the dementia spectrum.

Results

We selected 30 items covering the entire spectrum of IADL functioning. Internal consistency (0.98) and concordance with the original version (0.97) were very high. Concordance with the MMSE (0.72) and DAD (0.87) scores was high. IADL impairment scores increased across the spectrum from normal cognition to dementia.

Discussion

The A-IADL-Q short version (A-IADL-Q-SV) consists of 30 items and has maintained the psychometric quality of the original A-IADL-Q. As such, the A-IADL-Q-SV is a concise measure of functional decline.

A composite measure of cognitive and functional progression in Alzheimer's disease: Design of the Capturing Changes in Cognition study

INTRODUCTION

Cognitive testing in Alzheimer's disease (AD) is essential for establishing diagnosis, monitoring progression, and evaluating treatments. Assessments should ideally be brief, reliable, valid, and reflect clinically meaningful changes. There is a lack of instruments that meet all these criteria. In the Capturing Changes in Cognition (Catch-Cog) study, we seek to correct these deficiencies through the development and validation of a composite measure combining cognition and function: the cognitive-functional composite (CFC). We expect that the CFC is able to detect clinically relevant changes over time in early dementia stages of AD.

METHODS/DESIGN

We will include patients (n = 350) with mild cognitive impairment or mild dementia due to AD from memory clinics in the Netherlands and the United Kingdom. We will include cognitively healthy volunteers (n = 30) as a control group. The CFC is based on the "cognitive composite" and the Amsterdam instrumental activities of daily living questionnaire. We will investigate test-retest reliability with baseline and 2- to 3-week follow-up assessments (n = 50 patients and n = 30 healthy controls). We will involve experts and participants to evaluate the initial feasibility and refine the CFC if needed. Subsequently, we will perform a longitudinal construct validation study in a prospective cohort (n = 300) with baseline, 3-, 6-, and 12-month follow-up assessments. The main outcome is cognitive and functional progression measured by the CFC. Reference measures for progression include traditional cognitive and functional tests, disease burden measures, and brain imaging methods. Using linear mixed modeling, we will investigate longitudinal changes on the CFC and relate these to the reference measures. Using linear regression analyses, we will evaluate the influence of possible confounders such as age, gender, and education on the CFC.

DISCUSSION

By performing an independent longitudinal construct validation, the Catch-Cog study of the novel CFC will contribute to the improvement of disease monitoring and treatment evaluation in early dementia stages of AD.