Detecting prodromal Alzheimer's disease in mild cognitive impairment: utility of the CAMCOG and other neuropsychological predictors

Exploring easily accessible neurophysiological biomarkers for predicting Alzheimer's disease progression: a systematic review

Alzheimer disease (AD) remains a significant global health concern. The progression from preclinical stages to overt dementia has become a crucial point of interest for researchers. This paper reviews the potential of neurophysiological biomarkers in predicting AD progression, based on a systematic literature search following PRISMA guidelines, including 55 studies. EEG-based techniques have been predominantly employed, whereas TMS studies are less common. Among the investigated neurophysiological measures, spectral power measurements and event-related potentials-based measures, including P300 and N200 latencies, have emerged as the most consistent and reliable biomarkers for predicting the likelihood of conversion to AD. In addition, TMS-based indices of cortical excitability and synaptic plasticity have also shown potential in assessing the risk of conversion to AD. However, concerns persist regarding the methodological discrepancies among studies, the accuracy of these neurophysiological measures in comparison to established AD biomarkers, and their immediate clinical applicability. Further research is needed to validate the predictive capabilities of EEG and TMS measures. Advancements in this area could lead to cost-effective, reliable biomarkers, enhancing diagnostic processes and deepening our understanding of AD pathophysiology.

Predictive Models for the Transition from Mild Neurocognitive Disorder to Major Neurocognitive Disorder: Insights from Clinical, Demographic, and Neuropsychological Data

Neurocognitive disorders (NCDs) are progressive conditions that severely impact cognitive function and daily living. Understanding the transition from mild to major NCD is crucial for personalized early intervention and effective management. Predictive models incorporating demographic variables, clinical data, and scores on neuropsychological and emotional tests can significantly enhance early detection and intervention strategies in primary healthcare settings. We aimed to develop and validate predictive models for the progression from mild NCD to major NCD using demographic, clinical, and neuropsychological data from 132 participants over a two-year period. Generalized Estimating Equations were employed for data analysis. Our final model achieved an accuracy of 83.7%. A higher body mass index and alcohol drinking increased the risk of progression from mild NCD to major NCD, while female sex, higher praxis abilities, and a higher score on the Geriatric Depression Scale reduced the risk. Here, we show that integrating multiple factors-ones that can be easily examined in clinical settings-into predictive models can improve early diagnosis of major NCD. This approach could facilitate timely interventions, potentially mitigating the progression of cognitive decline and improving patient outcomes in primary healthcare settings. Further research should focus on validating these models across diverse populations and exploring their implementation in various clinical contexts.

Clinical validity of the Italian adaptation of the Uniform Data Set Neuropsychological Test Battery (I-UDSNB) in Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND

The identification and staging of Alzheimer's Disease (AD) represent a challenge, especially in the prodromal stage of Mild Cognitive Impairment (MCI), when cognitive changes can be subtle. Worldwide efforts were dedicated to select and harmonize available neuropsychological instruments. In Italy, the Italian Network of Neuroscience and Neuro-Rehabilitation has promoted the adaptation of the Uniform Data Set Neuropsychological Test Battery (I-UDSNB), collecting normative data from 433 healthy controls (HC). Here, we aimed to explore the ability of I-UDSNB to differentiate between a) MCI and HC, b) AD and HC, c) MCI and AD.

METHODS

One hundred thirty-seven patients (65 MCI, 72 AD) diagnosed after clinical-neuropsychological assessment, and 137 HC were included. We compared the I-UDSNB scores between a) MCI and HC, b) AD and HC, c) MCI and AD, with t-tests. To identify the test(s) most capable of differentiating between groups, significant scores were entered in binary logistic and in stepwise regressions, and then in Receiver Operating Characteristic curve analyses.

RESULTS

Two episodic memory tests (Craft Story and Five Words test) differentiated MCI from HC subjects; Five Words test, Semantic Fluency (vegetables), and TMT-part B differentiated AD from, respectively, HC and MCI.

CONCLUSIONS

Our findings indicate that the I-UDSNB is a suitable tool for the harmonized and concise assessment of patients with cognitive decline, showing high sensitivity and specificity for the diagnosis of MCI and AD.

Influencing factors on instrumental activities of daily living functioning in people with mild cognitive disorder - a secondary investigation of cross-sectional data

BACKGROUND

Finding a strategy to reduce the impact of cognitive decline on everyday functioning in persons suffering from cognitive impairment is a public health priority. Instrumental activities of daily living (IADL) are key to everyday functioning. Hence, it is essential to understand the influencing factors on IADL to develop specific interventions to improve everyday functioning in persons with mild cognitive disorder. Therefore, this study aimed to 1) explore different influencing factors on IADL functioning considering all domains of the International Classification of Functioning, disability, and health and 2) rank these factors.

METHODS

We performed a secondary analysis of a cohort including participants with amnestic mild cognitive impairment (a-MCI) or mild Alzheimer's Dementia (mild AD). The IADL functioning model was used as a starting point to estimate the effects of cognitive and physical function factors and personal and environmental factors on IADL functioning using multiple linear regression analysis, including subgroup analysis in persons with a-MCI. We used standardized coefficient estimates to relate the size of the predictor effects in the final model.

RESULTS

We included 105 participants (64 a-MCI, 41 mild AD); the mean age was 81.9 years (SD 4.9), with 70% females. Based on a multi-step approach and model fit, the final model included IADL functioning as the response variable and memory, attention, executive function, vision and hearing, mobility, balance, education, and social support as predictors. The final model explained 75% of the variability. The significant predictors in the model were mobility, balance, attention, and education, and were the predictors with the most considerable effects based on standardized coefficient estimates. The subgroup analysis, including only a-MCI participants, revealed a similar pattern.

CONCLUSION

Our results confirm that IADL functioning in people with mild cognitive disorder is influenced by cognitive and physical function and personal factors. The study provides further insight into understanding IADL functioning impairments in persons with mild impaired cognition and may be used to develop specific non-pharmacological interventions.

The Usefulness of Evaluating Performance of Activities in Daily Living in the Diagnosis of Mild Cognitive Disorders

The Assessment of Activities of Daily Living (ADL) is paramount to ensure the accurate early diagnosis of neurocognitive disorders. Unfortunately, the most common ADL tools are limited in their use in a diagnostic process. Hence, we set out to validate a tool to evaluate basic (b-), instrumental (i-), and advanced (a-) ADL called the Brussels Integrated Activities of Daily Living Inventory (BIA). At the geriatric day hospital of the University Hospital Brussels (Belgium) older persons (65+) labelled as Cognitively Healthy Persons (CHP) (n = 47), having a Mild Cognitive Impairment (MCI) (n = 39), and having Alzheimer's disease (AD) (n = 44) underwent a diagnostic procedure for neurocognitive disorders. Additionally, the BIA was carried out. An exploration using both (cumulative) logistic regressions and conditional inference trees aimed to select the most informative scales to discriminate between the HCP, persons with MCI and AD. The distinction between CHP and MCI and between MCI and AD was moderately successful with the i-ADLs, in addition to age. Therefore, it is advisable to conduct a multidomain assessment in which the i-ADL could serve as non-invasive and non-time-consuming screening, while the BIA might be useful for diagnostics and disease management.

A Lack of Practice Effects on Memory Tasks Predicts Conversion to Alzheimer Disease in Patients With Amnestic Mild Cognitive Impairment

The aim of the current study was to test the accuracy of practice effects, that is, improvement in test performance due to repeated neuropsychological evaluations, in identifying patients with amnestic mild cognitive impairment (a-MCI) at greater risk of conversion to Alzheimer disease (AD). For this purpose, we conducted a longitudinal study of 54 patients diagnosed with a-MCI at the first assessment and followed-up for 4 years. During this time, 18 patients converted to AD. Baseline and 6- to 12-month follow-up performances on a large set of neuropsychological tests were analyzed to determine their diagnostic ability to predict later conversion to dementia. Results demonstrate that a lack of practice effects on episodic memory tests is an accurate prognostic indicator of late conversion to AD in a-MCI patients. In fact, even though the performance of both groups was substantially comparable at the baseline evaluation, stable a-MCI patients greatly improved their memory performance at retest after 6 to 12 months; instead, scores of converter a-MCI remained stable or decreased passing from baseline to follow-up. Standardized z-change scores on memory tasks, which were computed as a reliable measure of performance change, classified group membership with very good overall accuracy, which was higher than the classification of converter and stable a-MCIs provided by baseline or follow-up scores. We hypothesize that the lack of practice effects on memory tasks mirrors the early involvement of medial temporal lobe areas in converter a-MCI that are fundamental for the consolidation of new memory traces.

Brief version of the CAMCOG for illiterate older adults with Alzheimer's dementia

BACKGROUND

The Cambridge Cognition Examination (CAMCOG) is one of the most used cognitive assessment batteries for older adults.

OBJECTIVE

To evaluate a brief version of the CAMCOG for illiterate older adults (CAMCOG-BILL) with Alzheimer's dementia (AD) and healthy controls (CG).

METHODS

Cross-sectional case-control study with 246 illiterate older adults (AD [n=159] and CG [n=87], composed by healthy seniors without cognitive complaints) who never attended school or took reading or writing lessons. Diagnosis of AD was established based on the NIA-AA and DSM-5 criteria. All participants were assessed with the CAMCOG by a researcher blinded for diagnosis. To assess the consistency of the chosen CAMCOG-BILL sub-items, we performed a binary logistic regression analysis.

RESULTS

Both the CAMCOG and the CAMCOG-BILL had satisfactory psychometric properties. The area under the curve (AUC) was 0.932 (p<0.001) for the original version of CAMCOG and 0.936 for the CAMCOG-BILL. Using a cut-off score of ≥60 (CAMCOG) and ≥44 (CAMCOG-BILL), both instruments had the same sensitivity and specificity (89 and 96%, respectively).

CONCLUSION

The CAMCOG-BILL may be a preferred tool because of the reduced test burden for this vulnerable subgroup of illiterate patients with dementia.

Using a Discourse Task to Explore Semantic Ability in Persons With Cognitive Impairment

This paper uses a discourse task to explore aspects of semantic production in persons with various degree of cognitive impairment and healthy controls. The purpose of the study was to test if an in-depth semantic analysis of a cognitive-linguistic challenging discourse task could differentiate persons with a cognitive decline from those with a stable cognitive impairment. Both quantitative measures of semantic ability, using tests of oral lexical retrieval, and qualitative analysis of a narrative were used to detect semantic difficulties. Besides group comparisons a classification experiment was performed to investigate if the discourse features could be used to improve classification of the participants who had a stable cognitive impairment from those who had cognitively declined. In sum, both types of assessment methods captured difficulties between the groups, but tests of oral lexical retrieval most successfully differentiated between the cognitively stable and the cognitively declined group. Discourse features improved classification accuracy and the best combination of features discriminated between participants with a stable cognitive impairment and those who had cognitively declined with an area under the curve (AUC) of 0.93.

Clinical utility of mild cognitive impairment subtypes and number of impaired cognitive domains at predicting progression to dementia: A 20-year retrospective study

OBJECTIVE

To determine the utility of mild cognitive impairment (MCI) subtypes and number of impaired cognitive domains on initial assessment at predicting progression to dementia in a sample of memory clinic patients over a 20-year period.

METHODS

A retrospective analysis was conducted of those presenting to a memory clinic with MCI from 1 January 1999 to 31 December 2018 inclusive. Those with MCI were broken down into one of the four subtypes using recommended cut-off scores on the Cambridge Cognitive Assessment (CAMCOG). Binomial logistic regression analysis was used to determine the utility of MCI subtypes and number of impaired cognitive domains as predictors for dementia.

RESULTS

Overall 1188 individuals with MCI diagnosis were identified, with 378 (32%) progressing to dementia, with median [range] time to diagnosis of 2 years [1-8.4]. Six hundred and forty-nine (55%) were identified as amnestic MCI and 539 (45%) as non-amnestic MCI. Amnestic MCI was a significant predictor of progression compared to non-amnestic MCI (OR = 1.85, df = 1, P < .001). Number of cognitive domains impaired was also a significant predictor of progression to dementia (OR = 1.07, df = 1, P = .01) but the single-/multi-domain distinction was not (OR = 1.29, df = 1, P = .36).

CONCLUSION

This study shows that approximately 32% of those diagnosed with MCI in a memory clinic progressed to dementia, with a median time to progression of 2 years. Those with amnestic MCI are almost twice as likely to progress to dementia than non-amnestic MCI and that therefore this is a useful distinction. However, the utility of the single- and multi-domain MCI distinction is called into question by our findings.

Combining Cognitive Markers to Identify Individuals at Increased Dementia Risk: Influence of Modifying Factors and Time to Diagnosis

OBJECTIVE

We investigated the extent to which combining cognitive markers increases the predictive value for future dementia, when compared to individual markers. Furthermore, we examined whether predictivity of markers differed depending on a range of modifying factors and time to diagnosis.

METHOD

Neuropsychological assessment was performed for 2357 participants (60+ years) without dementia from the population-based Swedish National Study on Aging and Care in Kungsholmen. In the main sample analyses, the outcome was dementia at 6 years. In the time-to-diagnosis analyses, a subsample of 407 participants underwent cognitive testing 12, 6, and 3 years before diagnosis, with dementia diagnosis at the 12-year follow-up.

RESULTS

Category fluency was the strongest individual predictor of dementia 6 years before diagnosis [area under the curve (AUC) = .903]. The final model included tests of verbal fluency, episodic memory, and perceptual speed (AUC = .913); these three domains were found to be the most predictive across a range of different subgroups. Twelve years before diagnosis, pattern comparison (perceptual speed) was the strongest individual predictor (AUC = .686). However, models 12 years before diagnosis did not show significantly increased predictivity above that of the covariates.

CONCLUSIONS

This study shows that combining markers from different cognitive domains leads to increased accuracy in predicting future dementia 6 years later. Markers from the verbal fluency, episodic memory, and perceptual speed domains consistently showed high predictivity across subgroups stratified by age, sex, education, apolipoprotein E ϵ4 status, and dementia type. Predictivity increased closer to diagnosis and showed highest accuracy up to 6 years before a dementia diagnosis. (JINS, 2020, 00, 1-13).

Does Empirically Derived Classification of Individuals with Subjective Cognitive Complaints Predict Dementia?

(1) Background: Early identification of mild cognitive impairment (MCI) in people reporting subjective cognitive complaints (SCC) and the study of progression of cognitive decline are important issues in dementia research. This paper examines whether empirically derived procedures predict progression from MCI to dementia. (2) Methods: At baseline, 192 participants with SCC were diagnosed according to clinical criteria as cognitively unimpaired (70), single-domain amnestic MCI (65), multiple-domain amnestic MCI (33) and multiple-domain non-amnestic MCI (24). A two-stage hierarchical cluster analysis was performed for empirical classification. Categorical regression analysis was then used to assess the predictive value of the clusters obtained. Participants were re-assessed after 36 months. (3) Results: Participants were grouped into four empirically derived clusters: Cluster 1, similar to multiple-domain amnestic MCI; Cluster 2, characterized by subjective cognitive decline (SCD) but with low scores in language and working memory; Cluster 3, with specific deterioration in episodic memory, similar to single-domain amnestic MCI; and Cluster 4, with SCD but with scores above the mean in all domains. The majority of participants who progressed to dementia were included in Cluster 1. (4) Conclusions: Cluster analysis differentiated between MCI and SCD in a sample of people with SCC and empirical criteria were more closely associated with progression to dementia than standard criteria.

The relationship between basic, instrumental, and advanced activities of daily living and executive functioning in geriatric patients with neurocognitive disorders

OBJECTIVE

Although many studies explored the relationship between executive functions (EF) and activities of daily living (ADLs) in cognitive disorders, previous studies used measurements without well-defined levels of ADLs. This study explored the relationship between EF and the threefold classification of everyday functioning (basic or b-, instrumental or i-, and advanced or a-ADLs) and examined how EF account for the variance in this triad of everyday functioning.

METHODS

A sample of 44 cognitively healthy persons, 41 persons with mild cognitive impairment, and 35 persons with Alzheimer disease were assessed with comprehensive measures of EF and the b-, i-, and a-ADL tools.

RESULTS

Correlations demonstrated that subjects with higher executive dysfunctions have more limitations in b-, i-, and a-ADLs. The highest significant correlations with measures of EF were seen in i- and a-ADLs (ranging from r = -0.193 to r = -0.559, P < 0.05). However, correlations with a-ADLs were not stronger than with i-ADLs. The multivariate analyses revealed Trail Making Test A (TMT-A) as a significant contributor of everyday functioning in b-ADLs, as well as i- and a-ADLs, and Clock Drawing Test (CDT) and Animal Fluency Test (AFT) seemed to contribute significantly to variance in i- and a-ADLs.

CONCLUSIONS

EF are less related to b-ADLs than i- and a-ADLs and contribute to the same amount of variance to limitations in both i- and a-ADLs. This study recommends using the TMT-A, CDT, and AFT as screening tools to indicate the need for profound evaluation of ADLs in older persons with neurocognitive disorders.

Convergent and concurrent validity of a report- versus performance-based evaluation of everyday functioning in the diagnosis of cognitive disorders in a geriatric population

ABSTRACTBackground:Several methods have been developed to evaluate activities of daily living (ADLs) in mild cognitive impairment (MCI) and mild dementia. This study evaluated the convergent and concurrent validity between (1) two report-based methods (the advanced (a)- and instrumental (i)-ADL tools) and (2) a performance-based method (the Naturalistic Action Test (NAT)) to check if their ability to differentiate between cognitively healthy comparisons (HCs), persons with MCI, and persons with mild Alzheimer's disease (AD) are comparable to each other.

METHOD

This was a cross-sectional study, undertaken in a geriatric day hospital. The participants comprised community-dwelling HCs (n = 21, median age 78.0 years, 61.9% female), MCI (n = 20, median age 79.5 years, 55.0% female), and AD (n = 20, median age 80.0 years, 85.0% female) adults. A diagnostic procedure for neurocognitive disorders was employed. In addition, the a- and i-ADL tools and the NAT were administered separately by blinded raters.

RESULTS

The NAT and both the a- and i-ADL tools showed significant differences between HCs, MCI, and AD participants. Convergent validity showed moderate to strong significant correlations between the NAT, and a- and i-ADL tools (range -0.583 to -0.663; p &lt; 0.01). Concurrent validity showed that the NAT (AUC 0.809-1.000) and the a- and i-ADL tools (AUC 0.739-0.964) presented comparable discriminatory accuracy (p = 0.0588).

CONCLUSIONS

In contrast to prior studies comparing report-based and performance-based methods of assessing ADL, this study indicates that the NAT and the a- and i-ADL tools have strong convergent and concurrent validity, and appear to have similar discriminatory power in differentiating between HCs, MCI, and AD.

Predictors of cognitive stability or decline during aging: A longitudinal study in primary care

We aimed to identify the early predictors of cognitive decline, and primary care physicians' (PCP) ability to diagnose cognitively impaired subjects, in a cohort of individuals recruited in primary care centers. Independent adults, aged ≥50 years at inception, with an overall low level of education, undertook a prospective clinical and cognitive evaluation targeting memory, attention and executive functions. At follow-up subjects were classified as cognitively normal (CN) or impaired (CI). Of 275 subjects (70.4 ± 8.3 years old, 176 females, 7.5 ± 4.4 education, 162 with MRI), 31 (11.2%) presented CI 4.9 years later, the majority (64.5%) presenting subjective cognitive complaints. PCP could correctly identify 40% of CI individuals, particularly if they presented current cognitive complaints. Male sex (OR = 3.117; CI95%: 1.007-9.645), age (OR = 1.063; CI95%: 1.004-1.126) and baseline scores on TMT-B (OR = 0.225; CI95%: 0.073-0.688) and Vocabulary (OR =  0.940; 95% CI: 0.894-0.986) predicted CI. This study shows that measures indicating poor cognitive reserve and low executive performance (as shown by low vocabulary and executive test scores, respectively) can be early indicators of the risk of decline, stressing the role of cognitive assessment as part of prevention/early intervention programs. The results also underline the need to help PCP to improve the detection of subjects with cognitive decline.

Improving clarity and transparency in cognitive assessment: conversion of the Cambridge Cognition Examination to the International Classification of Functioning, Disability and Health

BACKGROUND

A variety of screening, diagnostic and assessment tools have been developed for use in dementia research and care. However, there is no consensus which tool to use and moreover there is no transparency in communication between countries and disciplines.

OBJECTIVE

To contribute to a more uniform assessment in dementia, the Cambridge Cognition Examination (CAMCOG) was converted to the International Classification of Functioning, Disability and Health (ICF).

METHODS

In a qualitative design, CAMCOG-items and -scoring-system were converted to the ICF addressing 3 ICF domains: global and specific mental functions and general tasks and demands. Construct and discriminative validity was checked in a sample of 25 cognitively healthy elderly (CHE), 25 persons with Mild Cognitive Impairment (MCI) and 25 patients with mild Alzheimer's Disease (mAD).

RESULTS

A significant correlation was observed between CAMCOG/ICF-CAMCOG (r = - 0.987; p < 0.01). The areas under the curve (AUC) of the ICF-CAMCOG were between 0.819 and 0.978; comparable with the original CAMCOG. Only a significant difference between the AUC of the CHE versus MCI (0.911 vs. 0.819; p = 0.0094) was observed in favour of CAMCOG.

CONCLUSION

The clinical use of the ICF-CAMCOG looks promising offering a more detailed and interpretable scoring and may allow for better planning of resources to aid patients with dementia.

Cognitive Efficiency in Alzheimer's Disease is Associated with Increased Occipital Connectivity

There are cognitive domains which remain fully functional in a proportion of Alzheimer's disease (AD) patients. It is unknown, however, what distinctive mechanisms sustain such efficient processing. The concept of "cognitive efficiency" was investigated in these patients by operationalizing it as a function of the level of performance shown on the Letter Fluency test, on which, very often, patients in the early stages of AD show unimpaired performance. Forty-five individuals at the prodromal/early stage of AD (diagnosis supported by subsequent clinical follow-ups) and 45 healthy controls completed a battery of neuropsychological tests and an MRI protocol which included resting state acquisitions. The Letter Fluency test was the only task on which no between-group difference in performance was found. Participants were divided into "low-performing" and "high-performing" according to the global median. Dual-regression methods were implemented to compute six patterns of network connectivity. The diagnosis-by-level of performance interaction was inferred on each pattern to determine the network distinctiveness of efficient performance in AD. Significant interactions were found in the anterior default mode network, and in both left and right executive control networks. For all three circuits, high-performing patients showed increased connectivity within the ventral and dorsal part of BA19, as confirmed by post hoc t tests. Peristriate remapping is suggested to play a compensatory role. Since the occipital lobe is the neurophysiological source of long-range cortical connectivity, it is speculated that the physiological mechanisms of functional connectivity might sustain occipital functional remapping in early AD, particularly for those functions which are sustained by areas not excessively affected by the prodromal disease.

Clinical validity of delayed recall tests as a gateway biomarker for Alzheimer's disease in the context of a structured 5-phase development framework

Although Alzheimer's disease criteria promote the use of biomarkers, their maturity in clinical routine still needs to be assessed. In the light of the oncology framework, we conducted a literature review on measures used to assess delayed recall impairment due to medial temporal lobe dysfunction (i.e., free and cued word list recall tests). Ample evidence is available for phases 1 (rationale for use), 2 (discriminative ability), and 3 (early detection ability) for many of the tests in routine use. Evidence about phase 4 (performance in real world) and phase 5 (quantify impact and costs) is yet to come. Administration procedures have been standardized and cutoff scores are well validated in large Alzheimer's disease and mild cognitive impaired series. Some aspects (e.g., different task formats), however, hamper the comparability of results among different populations and the reproducibility between laboratories. No definite guideline for their use can thus be proposed at the moment. Accordingly, the maturity of such markers is not yet sufficient and requires future investigation to promote the proper use of memory measures in clinical settings.

Neuropsychological Measures that Predict Progression from Mild Cognitive Impairment to Alzheimer's type dementia in Older Adults: a Systematic Review and Meta-Analysis

This study aimed to determine the extent to which cognitive measures can predict progression from mild cognitive impairment (MCI) to Alzheimer’s type dementia (AD), assess the predictive accuracy of different cognitive domain categories, and determine whether accuracy varies as a function of age and length of follow-up. We systematically reviewed and meta-analyzed data from longitudinal studies reporting sensitivity and specificity values for neuropsychological tests to identify individuals with MCI who will develop AD. We searched articles in Medline, Cochrane, EMBASE, PsycINFO, and the Web of Science. Methodological quality was assessed using the STARDem and QUADAS standards. Twenty-eight studies met the eligibility criteria (2365 participants) and reported predictive values from 61 neuropsychological tests with a 31-month mean follow-up. Values were pooled to provide combined accuracy for 14 cognitive domains. Many domains showed very good predictive accuracy with high sensitivity and specificity values (≥ 0.7). Verbal memory measures and many language tests yielded very high predictive accuracy. Other domains (e.g., executive functions, visual memory) showed better specificity than sensitivity. Predictive accuracy was highest when combining memory measures with a small set of other domains or when relying on broad cognitive batteries. Cognitive tests are excellent at predicting MCI individuals who will progress to dementia and should be a critical component of any toolkit intended to identify AD at the pre-dementia stage. Some tasks are remarkable as early indicators, whereas others might be used to suggest imminent progression.

Longitudinal Assessment of Verbal Learning and Memory in Amnestic Mild Cognitive Impairment: Practice Effects and Meaningful Changes

Objectives: To identify learning effects and meaningful changes in amnestic mild cognitive impairment (aMCI) at a follow-up assessment.

Method: The Spanish version of the California Verbal Learning Test (CVLT) was administered to a sample of 274 adults of age over 50 years with subjective memory complains (SMC), including single and multiple domain aMCI groups and participants with SMC but without cognitive impairment (SMC group). The Wilcoxon test was used to compare results at baseline and after 18 months in short and long recall, and standardized regression-based (SRB) methods were used to study meaningful changes.

Results: Scores were significantly higher at follow-up for short and long-delayed recall in all groups indicating generalized practice effect. SRB scores indicated a significant decline in recall in a higher proportion of participants with aMCI than in SMC group.

Discussion: Patients with multiple and single domain aMCI benefit from practice in a verbal learning memory test. The SRB approach revealed a higher incidence of meaningful decline in short and long-delay recall and recognition in the aMCI groups than in the SMC group. Specifically, compared to SMC participants, single-domain aMCI individuals declined in a higher proportion in all measures, and multiple-domain aMCI individuals in long delay free recall.

Early diagnosis of mild cognitive impairment and mild dementia through basic and instrumental activities of daily living: Development of a new evaluation tool

BACKGROUND

Assessment of activities of daily living (ADL) is paramount to determine impairment in everyday functioning and to ensure accurate early diagnosis of neurocognitive disorders. Unfortunately, most common ADL tools are limited in their use in a diagnostic process. This study developed a new evaluation by adopting the items of the Katz Index (basic [b-] ADL) and Lawton Scale (instrumental [i-] ADL), defining them with the terminology of the International Classification of Human Functioning, Disability and Health (ICF), adding the scoring system of the ICF, and adding the possibility to identify underlying causes of limitations in ADL.

METHODS AND FINDINGS

The construct validity, interrater reliability, and discriminative validity of this new evaluation were determined. From 2015 until 2016, older persons (65-93 y) with normal cognitive ageing (healthy comparison [HC]) (n = 79), mild cognitive impairment (MCI) (n = 73), and Alzheimer disease (AD) (n = 71) underwent a diagnostic procedure for neurocognitive disorders at the geriatric day hospital of the Universitair Ziekenhuis Brussel (Brussels, Belgium). Additionally, the ICF-based evaluation for b- and i-ADL was carried out. A global disability index (DI), a cognitive DI (CDI), and a physical DI (PDI) were calculated. The i-ADL-CDI showed high accuracy and higher discriminative power than the Lawton Scale in differentiating HC and MCI (area under the curve [AUC] = 0.895, 95% CI .840-.950, p = .002), MCI and AD (AUC = 0.805, 95% CI .805-.734, p = .010), and HC and AD (AUC = 0.990, 95% CI .978-1.000, p < .001). The b-ADL-DI showed significantly better discriminative accuracy than the Katz Index in differentiating HC and AD (AUC = 0.828, 95% CI .759-.897, p = .039). This study was conducted in a clinically relevant sample. However, heterogeneity between HC, MCI, and AD and the use of different methods of reporting ADL might limit this study.

CONCLUSIONS

This evaluation of b- and i-ADL can contribute to the diagnostic differentiation between cognitively healthy ageing and neurocognitive disorders in older age. This evaluation provides more clarity and nuance in assessing everyday functioning by using an ICF-based terminology and scoring system. Also, the possibility to take underlying causes of limitations into account seems to be valuable since it is crucial to determine the extent to which cognitive decline is responsible for functional impairment in diagnosing neurocognitive disorders. Though further prospective validation is still required, the i-ADL-CDI might be useful in clinical practice since it identifies impairment in i-ADL exclusively because of cognitive limitations.

Case Finding of Mild Cognitive Impairment and Dementia and Subsequent Care; Results of a Cluster RCT in Primary Care

PURPOSE

Despite a call for earlier diagnosis of dementia, the diagnostic yield of case finding and its impact on the mental health of patients and relatives are unclear. This study assessed the effect of a two-component intervention of case finding and subsequent care on these outcomes.

METHODS

In a cluster RCT we assessed whether education of family physicians (FPs; trial stage 1) resulted in more mild cognitive impairment (MCI) and dementia diagnoses among older persons in whom FPs suspected cognitive decline and whether case finding by a practice nurse and the FP (trial stage 2) added to this number of diagnoses. In addition, we assessed mental health effects of case finding and subsequent care (trial stage 2). FPs of 15 primary care practices (PCPs = clusters) judged the cognitive status of all persons ≥ 65 years. The primary outcome, new MCI and dementia diagnoses by FPs after 12 months as indicated on a list, was assessed among all persons in whom FPs suspected cognitive impairment but without a formal diagnosis of dementia. The secondary outcome, mental health of patients and their relatives, was assessed among persons consenting to participate in trial stage 2. Trial stage 1 consisted of either intervention component 1: training FPs to diagnose MCI and dementia, or control: no training. Trial stage 2 consisted of either intervention component 2: case finding of MCI and dementia and care by a trained nurse and the FP, or control: care as usual.

RESULTS

Seven PCPs were randomized to the intervention; eight to the control condition. MCI or dementia was diagnosed in 42.3% (138/326) of persons in the intervention, and in 30.5% (98/321) in the control group (estimated difference GEE: 10.8%, OR: 1.51, 95%-CI 0.60-3.76). Among patients and relatives who consented to stage 2 of the trial (n = 145; 25%), there were no differences in mental health between the intervention and control group.

CONCLUSIONS

We found a non-significant increase in the number of new MCI diagnoses. As we cannot exclude a clinically relevant effect, a larger study is warranted to replicate ours.

TRIAL REGISTRATION

Nederlands Trial Register NTR3389.

Temporal changes in semantic and lexical access related to mild cognitive impairment

BACKGROUND

It has been hypothesized that the deterioration in the ability to name famous people in normal aging and cognitive impairment is a continuum in which meaning-based representations and form-based representations are differentially impaired, with early impairments in lexical access but not in semantic access.

AIMS

This hypothesis is tested in a follow-up study comparing the performance of fifty-six participants with amnestic mild cognitive impairment and forty-one control participants were assessed.

METHOD

A lexical task was conducted involving recognition and naming of famous people from photographs. Proportional semantic and phonological access measures were calculated.

RESULTS

Comparisons revealed significant differences between baseline and follow-up, with improvements in semantic access in the control group and decrements in phonological access in the group with amnestic mild cognitive impairment. Phonological access and reaction time measures were significantly and positively correlated, and semantic access and reaction time were significantly and negatively correlated.

CONCLUSIONS

These results add evidence to the hypothesis that the decrease of processing resources is related to the increase of difficulties in lexical access throughout aging. Patterns of change must be replicated over longer periods of time.

Walking ability to predict future cognitive decline in old adults: A scoping review

Early identification of individuals at risk for cognitive decline may facilitate the selection of those who benefit most from interventions. Current models predicting cognitive decline include neuropsychological and/or biological markers. Additional markers based on walking ability might improve accuracy and specificity of these models because motor and cognitive functions share neuroanatomical structures and psychological processes. We reviewed the relationship between walking ability at one point of (mid) life and cognitive decline at follow-up. A systematic literature search identified 20 longitudinal studies. The average follow-up time was 4.5 years. Gait speed quantified walking ability in most studies (n=18). Additional gait measures (n=4) were step frequency, variability and step-length. Despite methodological weaknesses, results revealed that gait slowing (0.68-1.1 m/sec) preceded cognitive decline and the presence of dementia syndromes (maximal odds and hazard ratios of 10.4 and 11.1, respectively). The results indicate that measures of walking ability could serve as additional markers to predict cognitive decline. However, gait speed alone might lack specificity. We recommend gait analysis, including dynamic gait parameters, in clinical evaluations of patients with suspected cognitive decline. Future studies should focus on examining the specificity and accuracy of various gait characteristics to predict future cognitive decline.

Reaction Time Measures Predict Incident Dementia in Community-Living Older Adults: The Sydney Memory and Ageing Study

OBJECTIVE

To examine the utility of intraindividual variability of reaction times (IIVRT) and mean reaction time (RT) as behavioral markers of incident all-cause dementia.

METHODS

A longitudinal cohort study followed biennially for 4 years, the community-based Sydney Memory and Ageing Study, 861 initially nondemented participants aged 70-90. Incident all-cause dementia determined by consensus, RT measures from simple and complex tasks, Mini-Mental State Exam and neuropsychological tests, Geriatric Depression Scale and Goldberg Anxiety Scale, cardiovascular risk score, apolipoprotein ε4 status, and the Bayer ADL Scale were used. Associations of baseline IIVRT and mean RT with time to dementia were evaluated with hazard ratios (HRs) using Cox proportional-hazards models with and without controlling for dementia risk factors.

RESULTS

Forty-eight cases developed dementia. Greater complex IIVRT predicted a 40% (HR: 1.43) and mean RT a 50%-60% (simple RT: HR 1.53; complex RT: HR 1.59) per standard deviation increased risk of developing dementia, remaining significant after controlling for age, education, sex, general cognitive function, mood, cerebrovascular disease, and genetic susceptibility. Prediction of incident dementia using demographical information and RT measures combined was comparable with several traditional neuropsychological measures (AUC 0.75), although lower than a full neuropsychological battery (AUC 0.90). Prediction of functional decline by RT measures combined was equal to the neuropsychological battery (multiple Rs of .233 and .238, respectively).

CONCLUSION

Brief RT measures provided information on risk of imminent dementia and functional decline within 4 years in older adults at a population level, with mean RT the stronger predictor.

Discriminative power of the advanced activities of daily living (a-ADL) tool in the diagnosis of mild cognitive impairment in an older population

BACKGROUND

Mild cognitive impairment (MCI) is characterized by subjective and objective memory impairments in the absence of manifest functional decline. Mild changes in activities of daily living (ADL) can be present and probably predict conversion to dementia. A new advanced (a)-ADL tool was developed, evaluating high-level activities and, taking each participant as their own reference, distinguishing a global Disability Index (a-ADL-DI), a Cognitive Disability Index (a-ADL-CDI), and a Physical Disability Index (a-ADL-PDI), based on the number of activities performed and the severity and causes of the functional problem. This study evaluates the discriminative validity of the a-ADL in MCI.

METHOD

Based upon clinical evaluation and a set of global, cognitive, mood, and functional assessments, 150 community-dwelling participants (average age 80.3 years (SD 5; 66-91)) were included and diagnosed as (1) cognitively healthy participants (n = 50); (2) patients with a-MCI (n = 48), or (3) mild to moderate AD (n = 52). The a-ADL tool was not a part of the clinical evaluation.

RESULTS

The a-ADL-DI and the a-ADL-CDI showed a sensitivity and specificity ranging from 70% to 94.2%, Positive Predictive Value ranging from 70% till 93.8%, and Negative Predictive Value from 64.4% and 93.8%, an area under the curve (AUC) ranging from 0.791 to 0.960. Functional decline related to physical deficits, as assessed by the a-ADL-PDI, did not discriminate between the different groups.

CONCLUSION

The a-ADL tool has a good ability to distinguish normal and pathological cognitive aging. Its discriminative power for underlying causes of limitations may be an advantage.

Dutch family physicians' awareness of cognitive impairment among the elderly

BACKGROUND

Dementia is often not formally diagnosed in primary care. To what extent this is due to family physicians' (FPs) watchful waiting, reluctance to diagnose or to their unawareness of the presence of cognitive impairment is unclear. The objective of this study was to assess FPs' awareness of cognitive impairment by comparing their evaluation of the absence or presence of cognitive impairment in older patients without an established diagnosis of dementia, with a reference test of cognitive functioning. In addition, we assessed which patient characteristics were associated with con- and discordance between FPs' evaluation of cognition and results of the reference test.

METHODS

The design was a nested diagnostic study. FPs (n = 29) of 15 primary care practices classified the cognitive status of all their patients ≥ 65 years of age (n = 7865) into four categories, based on recollection and medical records. All patients categorized as 'possible cognitive impairment or dementia' and a sample of patients categorized as 'no signs of cognitive impairment' randomly selected to match age and gender were offered to receive a reference test of cognitive function (the CAMCOG) to verify the FPs' label. This reference test could yield three outcomes: no cognitive impairment, amnestic mild cognitive impairment (aMCI) or dementia. Reference test results were weighted back to the original samples to provide estimates for the correct categorization of elderly as 'possible cognitive impairment or dementia' (positive predictive value [PPV]) and 'no signs of cognitive impairment' (negative predictive value [NPV]). Cognitive functioning was not assessed for patients evaluated by FPs as 'probable dementia' and 'unknown or no recent contact'. Characteristics associated with the con- or discordance of the FPs' classification and the reference test were assessed using logistic regression.

RESULTS

Complete reference test results were obtained from 318 elderly. FPs labeled 8.3 % of elderly 'possible cognitive impairment or dementia'. The PPV of this label for a CAMCOG score suggestive of dementia or aMCI was 47.1 % (95 %-confidence interval: 43.5 - 62.4 %). FPs labeled 83.7 % 'no signs of cognitive impairment'. The 1-NPV of this label for a CAMCOG score suggestive of dementia or aMCI was 12.5 % (95 %-CI 8.2 - 16.8 %). FPs labeled 3.6 % as 'probable dementia' and 4.5 % as 'unknown or no recent contact'. The odds that FPs' suspicion of cognitive impairment were confirmed by the CAMCOG were higher if persons were ADL dependent (OR 2.24 [95 %-CI 1.16 - 4.35]). The odds of FPs being unaware of the presence of cognitive impairment were higher in the older elderly (OR 1.15 [95 %-CI 1.09 - 1.23] per year).

CONCLUSION

Evaluation of FPs' classification of the global cognitive function of elderly without a firm diagnosis of dementia showed both over- and unawareness of the presence of cognitive impairment. FPs were more often unaware of cognitive impairment in the older elderly.

Longitudinal costs of caring for people with Alzheimer's disease

BACKGROUND

There has been an increasing interest in the relationship between severity of disease and costs in the care of people with dementia. Much of the current evidence is based on cross-sectional data, suggesting the need to examine trends over time for this important and growing cohort of the population.

METHODS

This paper estimates resource use and costs of care based on longitudinal data for 72 people with dementia in Ireland. Data were collected from the Enhancing Care in Alzheimer's Disease (ECAD) study at two time points: baseline and follow-up, two years later. Patients' dependence on others was measured using the Dependence Scale (DS), while patient function was measured using the Disability Assessment for Dementia (DAD) scale. Univariate and multivariate analysis were used to explore the effects of a range of variables on formal and informal care costs.

RESULTS

Total costs of formal and informal care over six months rose from €9,266 (Standard Deviation (SD): 12,947) per patient at baseline to €21,266 (SD: 26,883) at follow-up, two years later. This constituted a statistically significant (p = 0.0014) increase in costs over time, driven primarily by an increase in estimated informal care costs. In the multivariate analysis, a one-point increase in the DS score, that is a one-unit increase in patient's dependence on others, was associated with a 19% increase in total costs (p = 0.0610).

CONCLUSIONS

Higher levels of dependence in people with Alzheimer's disease are significantly associated with increased costs of informal care as the disease progresses. Formal care services did not respond to increased dependence in people with dementia, leaving it to families to fill the caring gap, mainly through increased supervision with the progress of disease.

An explorative study of the relationship between functional and cognitive decline in older persons with mild cognitive impairment and Alzheimer’s disease

Introduction

This study explored the relationship between functional decline on three advanced activities of daily living and cognitive decline in elderly persons. The use of everyday technology, driving a vehicle, and performing complex economic activities are advanced activities of daily living domains presumed to be sensitive to early cognitive decline and therefore of interest for the profession of occupational therapy.

Method

We included 45 persons with mild cognitive impairment, 48 persons with Alzheimer’s disease, and 50 cognitively healthy controls. Functional impairment due to cognitive decline was evaluated by the advanced activities of daily living tool. Cognitive disability indices were computed for the investigated advanced activities of daily living domains and correlated with the Mini Mental State Examination and the Cambridge Examination for Mental Disorders of the Elderly, Cognitive Part.

Results

The cognitive disability index for performing complex economic activities and the cognitive disability index for the three advanced activities of daily living domains together differed significantly between the three groups. For the whole sample, the advanced activity of daily living cognitive disability indices correlated strongly with the cognitive measures. Within each separate group, few correlations were found.

Conclusion

This study contributes to the field of knowledge for occupational therapy by emphasizing the value of assessment of advanced activities of daily living in early cognitive decline. For the occupational therapy profession, further research is required in the interaction between functional decline and cognition in early cognitive decline.

Visual memory profiling with CANTAB in mild cognitive impairment (MCI) subtypes

OBJECTIVE

Although visual memory has been shown to be impaired in amnestic mild cognitive impairment (aMCI), the differences between MCI subtypes are not well defined. The current study attempted to investigate visual memory profiles in different MCI subtypes.

METHODS

One hundred and seventy volunteers aged older than 50 years performed several visual memory tests included in the CANTAB battery. Participants were classified into four groups: (1) multiple domain aMCI (mda-MCI) (32 subjects); (2) single domain aMCI (sda-MCI)(57 subjects); (3) multiple domain non amnestic MCI (mdna-MCI) (32 subjects); and (4) controls (54 healthy individuals without cognitive impairment). Parametric and non parametric analyses were performed to compare the groups and to obtain their corresponding memory profiles.

RESULTS

The mda-MCI group exhibited impairments in both dimensions of episodic memory (recognition and recollection/recall), and also in learning and working memory, whereas the sda-MCI only showed impairment in recollection-delayed recall and learning. The mdna-MCI group displayed impairment in working memory but good preservation of learning and episodic memory.

CONCLUSION

The CANTAB visual memory profiles may contribute to better cognitive characterization of patients with different MCI subtypes, allowing comparison across several processes involved in visual memory such as attention, recognition, recollection and working memory.

Do the Cambridge Neuropsychological Test Automated Battery episodic memory measures discriminate amnestic mild cognitive impairment?

OBJECTIVE

Although visual recognition memory and visuospatial paired associates learning has been shown to be impaired in amnestic mild cognitive impairment (aMCI), the sensitivity and specificity of the visual memory tests used to identify aMCI are not well defined. The current study attempted to analyze the sensitivity and specificity of three visual episodic memory tests (Pattern Recognition Memory [PRM], Delayed Matching to Sample [DMS], and Paired Associated Learning [PAL]) from the CANTAB, in differentiating aMCI patients from control healthy participants.

METHODS

Seventy seven aMCI patients and 85 cognitive normal controls aged over 50 years performed the PRM, DMS, and PAL tests. Univariate and multivariate logistic regression and receiver operating characteristic curve analyses were used to study the relationships between aMCI and visual memory measures.

RESULTS

The three Cambridge Neuropsychological Test Automated Battery measures significantly predicted aMCI. The optimal predictive model combined the total percent correct responses for PRM and DMS with the PAL total errors (six shapes adjusted), with a sensitivity of 72%, specificity of 83%, and achieved predictive accuracy of 80%.

CONCLUSION

Visual episodic memory tasks such as those involved in the PRM, DMS, and PAL tests (included in the Cambridge Neuropsychological Test Automated Battery) may sensitively discriminate aMCI patients from normal controls. These tests may be useful for correct diagnosis of aMCI.

Electrophysiological correlates of amnestic mild cognitive impairment in a simon task

Amnestic mild cognitive impairment (aMCI) represents a prodromal stage of Alzheimer`s disease (AD), especially when additional cognitive domains are affected (Petersen et al., 2009). Thus, single-domain amnestic MCI (sdaMCI) and multiple-domain-amnestic MCI (mdaMCI) biomarkers are important for enabling early interventions to help slow down progression of the disease. Recording event-related potentials (ERPs) is a non-invasive and inexpensive measure of brain activity associated with cognitive processes, and it is of interest from a clinical point of view. The ERP technique may also be useful for obtaining early sdaMCI and mdaMCI biomarkers because ERPs are sensitive to impairment in processes that are not manifested at behavioral or clinical levels. In the present study, EEG activity was recorded in 25 healthy participants and 30 amnestic MCI patients (17 sdaMCI and 13 mdaMCI) while they performed a Simon task. The ERPs associated with visuospatial (N2 posterior-contralateral - N2pc -) and motor (lateralized readiness potential - LRP -) processes were examined. The N2pc amplitude was smaller in participants with mdaMCI than in healthy participants, which indicated a decline in the correlates of allocation of attentional resources to the target stimulus. In addition, N2pc amplitude proved to be a moderately good biomarker of mdaMCI subtype (0.77 sensitivity, 0.76 specificity). However, the LRP amplitude was smaller in the two MCI groups (sdaMCI and mdaMCI) than in healthy participants, revealing a reduction in the motor resources available to execute the response in sdaMCI and mdaMCI patients. Furthermore, the LRP amplitude proved to be a valid biomarker (0.80 sensitivity, 0.92 specificity) of both amnestic MCI subtypes.

Mismatch negativity (MMN) amplitude as a biomarker of sensory memory deficit in amnestic mild cognitive impairment

It has been suggested that changes in some event-related potential (ERP) parameters associated with controlled processing of stimuli could be used as biomarkers of amnestic mild cognitive impairment (aMCI). However, data regarding the suitability of ERP components associated with automatic and involuntary processing of stimuli for this purpose are not conclusive. In the present study, we studied the Mismatch Negativity (MMN) component, a correlate of the automatic detection of changes in the acoustic environment, in healthy adults and adults with aMCI (age range: 50-87 years). An auditory-visual attention-distraction task, in two evaluations separated by an interval of between 18 and 24 months, was used. In both evaluations, the MMN amplitude was significantly smaller in the aMCI adults than in the control adults. In the first evaluation, such differences were observed for the subgroup of adults between 50 and 64 years of age, but not for the subgroup of 65 years and over. In the aMCI adults, the MMN amplitude was significantly smaller in the second evaluation than in the first evaluation, but no significant changes were observed in the control adult group. The MMN amplitude was found to be a sensitive and specific biomarker of aMCI, in both the first and second evaluation.

Applications of technology in neuropsychological assessment

Most neuropsychological assessments include at least one measure that is administered, scored, or interpreted by computers or other technologies. Despite supportive findings for these technology-based assessments, there is resistance in the field of neuropsychology to adopt additional measures that incorporate technology components. This literature review addresses the research findings of technology-based neuropsychological assessments, including computer- and virtual reality-based measures of cognitive and functional abilities. We evaluate the strengths and limitations of each approach, and examine the utility of technology-based assessments to obtain supplemental cognitive and behavioral information that may be otherwise undetected by traditional paper-and-pencil measures. We argue that the potential of technology use in neuropsychological assessment has not yet been realized, and continued adoption of new technologies could result in more comprehensive assessment of cognitive dysfunction and in turn, better informed diagnosis and treatments. Recommendations for future research are also provided.

Does tip-of-the-tongue for proper names discriminate amnestic mild cognitive impairment?

BACKGROUND

Difficulty in retrieving people's names is very common in the early stages of Alzheimer's disease and mild cognitive impairment. Such difficulty is often observed as the tip-of-the-tongue (TOT) phenomenon. The main aim of this study was to explore whether a famous people's naming task that elicited the TOT state can be used to discriminate between amnestic mild cognitive impairment (aMCI) patients and normal controls.

METHODS

Eighty-four patients with aMCI and 106 normal controls aged over 50 years performed a task involving naming 50 famous people shown in pictures. Univariate and multivariate regression analyses were used to study the relationships between aMCI and semantic and phonological measures in the TOT paradigm.

RESULTS

Univariate regression analyses revealed that all TOT measures significantly predicted aMCI. Multivariate analysis of all these measures correctly classified 70% of controls (specificity) and 71.6% of aMCI patients (sensitivity), with an AUC (area under curve ROC) value of 0.74, but only the phonological measure remained significant. This classification value was similar to that obtained with the Semantic verbal fluency test.

CONCLUSIONS

TOTs for proper names may effectively discriminate aMCI patients from normal controls through measures that represent one of the naming processes affected, that is, phonological access.

The effects of dependence and function on costs of care for Alzheimer's disease and mild cognitive impairment in Ireland

OBJECTIVE

To explore the incremental effects of patient dependence and function on costs of care for patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (MCI) in Ireland.

METHODS

Cost analysis based on reported resource use for a cross-section of 100 community-based people with AD and MCI. Formal care included general practice visits, hospitalizations, outpatient clinic consultations, accident and emergency visits, respite care, meals on wheels services and other health and social care professional consultations. Informal care included time input provided by caregivers. Resource unit costs were applied to value formal care and the opportunity cost method was used to value informal care. Patient dependence on others was measured using the Dependence Scale and patient functional capacity using the Disability Assessment for Dementia scale. Multivariate regression analysis was used to model the cost of care.

RESULTS

Both dependence and function were independently and significantly associated with total formal and informal care cost: a one point increase in dependence was associated with a €796 increase in total cost and a one point improvement in function with a €417 reduction in total cost over 6 months. Patient function was significantly associated with formal care costs, whereas patient function and dependence were both significantly associated with informal care costs.

CONCLUSION

The costs of care for patients with AD and MCI in Ireland are substantial. Interventions that reduce patient dependence on others and functional decline may be associated with important economic benefits.

The role of B vitamins in preventing and treating cognitive impairment and decline

Many epidemiologic studies have considered whether markers of B-vitamin status are associated with cognitive function and cognitive decline. This avenue of research was sparked by the homocysteine (Hcy) theory of cardiovascular disease, which was extended to Alzheimer's disease when a link between vascular dementia and Alzheimer's disease was discovered. Hcy could cause cognitive impairment via direct neurotoxicity. However, decreased remethylation of Hcy to methionine might also compromise cognitive function by means other than mere Hcy lowering. Folate and vitamin B-12 participate in Hcy remethylation and largely determine Hcy status. Consequently, much of the relevant research has focused on these 2 B vitamins. The many subtly different hypotheses that investigators have addressed by attempting to link several B-vitamin status indicators to diverse cognition-related outcomes have created a confusing body of conflicting studies that seems to defy summarization. Nevertheless, themes are discernible that aid interpretation, foster hypothesis generation, and inform future study design. For example, despite a shared metabolic pathway, Hcy, vitamin B-12, and folate are differently related to specific cognitive outcomes. Although consistency of findings across studies is often touted as essential to distinguishing causal from coincidental relationships, discrepancies among study findings can be even more informative.

Case-finding of dementia in general practice and effects of subsequent collaborative care; design of a cluster RCT

BACKGROUND

In the primary care setting, dementia is often diagnosed relatively late in the disease process. Case finding and proactive collaborative care may have beneficial effects on both patient and informal caregiver by clarifying the cause of cognitive decline and changed behaviour and by enabling support, care planning and access to services.We aim to improve the recognition and diagnosis of individuals with dementia in general practice. In addition to this diagnostic aim, the effects of case finding and subsequent care on the mental health of individuals with dementia and the mental health of their informal carers are explored.

METHODS AND DESIGN

DESIGN

cluster randomised controlled trial with process evaluation.

PARTICIPANTS

162 individuals ≥ 65 years, in 15 primary care practices, in whom GPs suspect cognitive impairment, but without a dementia diagnosis.Intervention; case finding and collaborative care: 2 trained practice nurses (PNs) invite all patients with suspected cognitive impairment for a brief functional and cognitive screening. If the cognitive tests are supportive of cognitive impairment, individuals are referred to their GP for further evaluation. If dementia is diagnosed, a comprehensive geriatric assessment takes place to identify other relevant geriatric problems that need to be addressed. Furthermore, the team of GP and PN provide information and support.

CONTROL

GPs provide care and diagnosis as usual.Main study parameters: after 12 months both groups are compared on: 1) incident dementia (and MCI) diagnoses and 2) patient and caregiver quality of life (QoL-AD; EQ5D) and mental health (MH5; GHQ 12) and caregiver competence to care (SSCQ). The process evaluation concerns facilitating and impeding factors to the implementation of this intervention. These factors are assessed on the care provider level, the care recipient level and on the organisational level.

DISCUSSION

This study will provide insight into the diagnostic yield and the clinical effects of case finding and collaborative care for individuals with suspected cognitive impairment, compared to usual care. A process evaluation will give insight into the feasibility of this intervention.The first results are expected in the course of 2013.

TRIAL REGISTRATION

NTR3389.

Predictors of cognitive decline in Alzheimer's disease and mild cognitive impairment using the CAMCOG: a five-year follow-up

BACKGROUND

There are discrepant findings regarding which subscales of the Cambridge Cognitive Examination (CAMCOG) are able to predict cognitive decline. The study aimed to identify the baseline CAMCOG subscales that can discriminate between patients and predict cognitive decline in Alzheimer's disease (AD) and mild cognitive impairment (MCI).

METHODS

This was a five-year case-control study of patients with cognitive impairment and a control group. Participants were grouped into AD (n = 121), MCI converted to dementia (MCI-Ad, n = 43), MCI-stable (MCI-St, n = 66), and controls (CTR, n = 112). Differences in the mean scores obtained by the four groups were examined. Receiver operating characteristic curves were used to compare subscale scores in the AD and MCI-Ad groups with those of controls. The influence of age, gender, schooling, and depression on baseline subscale scores was assessed.

RESULTS

Of the CAMCOG subscales, Orientation and Memory (learning and recent) (OR + MEM) showed the highest discriminant capacity in the baseline analysis of the four groups. This baseline analysis indicated that OR + MEM was the best predictor of conversion to AD in the MCI-Ad group (area under the curve, AUC = 0.81), whereas the predictive capacity of the global MMSE and CAMCOG scores was poor (AUC = 0.59 and 0.53, respectively).

CONCLUSIONS

In the baseline analysis, the Orientation and Memory (learning and recent) subscales showed the highest discriminant and predictive capacity as regards both cognitive decline in the AD group and conversion to AD among MCI-Ad patients. This was not affected by age, gender, schooling, or depression.

Estimating the economic and social costs of dementia in Ireland

Dementia is a costly condition and one that differs from other conditions in the significant cost burden placed on informal caregivers. The aim of this analysis was to estimate the economic and social costs of dementia in Ireland in 2010. With an estimate of 41,470 people with dementia, the total baseline annual cost was found to be over €1.69 billion, 48% of which was attributable to the opportunity cost of informal care provided by family and friends and 43% to residential care. Due to the impact of demographic ageing in the coming decades and the expected increase in the number of people with dementia, family caregivers and the general health and social care system will come under increasing pressure to provide adequate levels of care. Without a significant increase in the amount of resources devoted to dementia, it is unclear how the system will cope in the future.

Self-efficacy for managing dementia may protect against burden and depression in Alzheimer's caregivers

BACKGROUND

Self-efficacy is the belief that one can perform a specific task or behaviour and is a modifiable attribute which has been shown to influence health behaviours. Few studies have examined the relationship between self-efficacy for dementia-related tasks and symptoms of burden and depression in caregivers.

METHODS

Eighty four patient/caregiver dyads with Alzheimer's disease were recruited through a memory clinic. Patient function, cognition and neuropsychiatric symptoms were assessed together with caregiver burden, personality, depressive symptoms, coping strategies and self-efficacy for completing tasks related to dementia care.

RESULTS

33% (28) of caregivers reported significant depressive symptoms (CES-D  ≥  10). In multivariate analyses, caregiver burden was predicted by self-efficacy for symptom management, neuroticism, patient function and neuropsychiatric symptoms while caregiver depression was predicted by self-efficacy for symptom management, caregiver educational level, neuroticism, emotion-focused coping, dysfunctional coping and patient function. In patients with moderate to severe impairment (MMSE  ≤  20), self-efficacy for symptom management behaved as a mediator between patient neuropsychiatric symptoms and symptoms of burden and depression in caregivers.

CONCLUSIONS

Further longitudinal investigation is warranted to determine if self-efficacy might be usefully considered a target in future interventional studies to alleviate symptoms of burden and depression in Alzheimer's caregivers.

Determinants of the desire to institutionalize in Alzheimer's caregivers

BACKGROUND

The desire to institutionalize is an important predictor of future institutionalization. Few studies have examined potentially modifiable caregiver characteristics which might be the focus of future interventional strategies.

METHODS

A total of 102 patient/caregiver dyads with Alzheimer's disease (n = 84) or mild cognitive impairment were recruited through a memory clinic. Cross-sectional analyses of a range of patients, caregivers, and context of care-related characteristics were conducted.

RESULTS

Caregiver desire to institutionalize was significantly associated with a number of potentially modifiable variables including caregiver coping style, self-efficacy, depression, burden, and the presence of an unmet service need. In a multivariate analysis, caregiver burden, depression, and nonspousal status were the only significant independent predictors of caregiver desire to institutionalize in a model which correctly classified 80.4% of caregivers.

CONCLUSIONS

Interventions which seek to reduce caregiver desire to institutionalize should adopt a multifactorial approach to reduce symptoms of burden and depression in caregivers.