Current guidelines for dementia screening: shortcomings and recommended changes

Norwegian version of the Edinburgh cognitive and behavioural ALS screen: Construct validity, internal consistency, inter-rater, and test-retest reliability

BACKGROUND

Research collaboration highlight a need for validated tests in other languages than English. Translation and culture adjustments may threaten essential features of the original instrument.

OBJECTIVE

To assess the internal consistency, inter-rater and test-retest reliability, and construct validity of the Norwegian version of the Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis (ALS) Screen (ECAS-N).

METHODS

Performance of 71 subjects with ALS, 85 healthy controls (HC) and 6 controls with Alzheimer's disease (AD) were assessed with the ECAS-N. Test-retest interval was four months. Internal consistency was evaluated using Cronbach's alpha; reliability was assessed using intraclass correlation coefficient (ICC), Cohen's kappa, and Bland Altman plot. Five hypothesis, including the Montreal Cognitive Assessment (MoCA) screen, was evaluated for construct validity.

RESULTS

ECAS-N total score produced a Cronbach's alpha of 0.65, had excellent inter-rater reliability (ICC = 0.99) and acceptable test-retest reliability (ICC = 0.73). Construct validity analysis suggested valid use of the ECAS-N to distinguish people with ALS-specific cognitive impairment from HC (p = 0.001) and those with AD (p = 0.002). The MoCA and ECAS-N were moderately correlated (r = 0.53).

CONCLUSION

The ECAS-N has potential to be used by different testers in clinical practice and research to screen patients with ALS who speak Norwegian and for documenting cognitive impairment over time.

Narrative Review of Sensory Changes as a Biomarker for Alzheimer's Disease

Early recognition of Alzheimer's disease (AD) in the prodromal period has not been robust yet will be necessary if effective disease-modifying drugs are to be useful in preventing or delaying the condition. The objective of this narrative review was to describe the current, evidenced based understanding of alterations in sensory data as potential biomarkers for AD. Review of empirical studies that tested senses as biomarkers for AD and were published in English within the past 50 years was completed. Eighteen empirical studies were identified that met the strict criteria for inclusion, with 12 of these studies being related to the olfactory system. Two studies examined auditory, two examined vision, one examined proprioception, and one examined taste. Thus, only olfaction has been studied to any extent, leaving a clear gap in the literature for the use of other senses. A promising area of research has begun to be reported concerning differences in responses to pain stimuli in AD relative to cognitively normal subjects. Pain is not a single sense like the others but integrates several senses and may allow for use as an early biomarker for AD, as it integrates several brain areas and pathways. Unlike the other senses, simple devices can be used to measure changes in pain perception in cognitively normal adults with genetic predispositions for possible AD, making this potentially useful for clinicians in the future.

Factors associated with slow progression of cognitive impairment following first dementia diagnosis

OBJECTIVES

To investigate the extent to which slow progression of dementia after diagnosis might be predicted from routine longitudinal healthcare data, in order to clarify characteristics of people who experience this outcome.

METHODS

A retrospective observational study was conducted using data from the South London and Maudsley NHS Foundation Trust Biomedical Research Centre Case Register. This study included all patients receiving a first dementia diagnosis between 2006 and 2017, restricted to those with a baseline Mini-Mental State Examination (MMSE) score within 6 months of initial diagnosis of dementia and at least one MMSE score after 3 years post-diagnosis. Slow progression was defined as a change in MMSE score of -1, 0 or an increase at the follow-up point. This group was compared to the remainder with an MMSE decline of -2 or more.

RESULTS

Overall, 682 patients with slow progression were compared to 1045 with faster progression. In the confounder-adjusted multivariate logistic regression model, slow progression was more likely in younger patients (age 65-74 years; odds ratio: 1.18; 95% confidence intervals: 1.04-1.37), males (1.24; 1.01-1.53), those with moderate or severe dementia according to MMSE, patients with mixed-type dementia (2.06; 1.11-3.82) compared to Alzheimer's disease and less likely in those receiving acetylcholinesterase inhibitor (AChEI) treatment (0.57; 0.46-0.71).

CONCLUSION

Slow dementia progression after diagnosis was common in patients with mixed Alzheimer's and vascular dementia, younger age, males and non-receipt of AChEIs, possibly suggesting non-Alzheimer pathologies and clarifying such predictors is important, as there is currently very limited information on which to base prognosis estimates in post-diagnosis counselling.

Using Optical Coherence Tomography to Screen for Cognitive Impairment and Dementia

BACKGROUND

Screening for Alzheimer's disease and related disorders (ADRD) and mild cognitive impairment (MCI) could increase case identification, enhance clinical trial enrollment, and enable early intervention. MCI and ADRD screening would be most beneficial if detection measures reflect neurodegenerative changes. Optical coherence tomography (OCT) could be a marker of neurodegeneration (part of the amyloid-tau-neurodegeneration (ATN) framework).

OBJECTIVE

To determine whether OCT measurements can be used as a screening measure to detect individuals with MCI and ADRD.

METHODS

A retrospective cross-sectional study was performed on 136 participants with comprehensive clinical, cognitive, functional, and behavioral evaluations including OCT with a subset (n = 76) completing volumetric MRI. Pearson correlation coefficients tested strength of association between OCT and outcome measures. Receiver operator characteristic curves assessed the ability of OCT, patient-reported outcomes, and cognitive performance measures to discriminate between individuals with and without cognitive impairment.

RESULTS

After controlling for age, of the 6 OCT measurements collected, granular cell layer-inner plexiform layer (GCL + IPL) thickness best correlated with memory, global cognitive performance, Clinical Dementia Rating, and hippocampal atrophy. GCL + IPL thickness provided good discrimination in cognitive status with a cut-off score of 75μm. Combining GCL + IPL thickness as a proxy marker for hippocampal atrophy with a brief patient-reported outcome and performance measure correctly classified 87%of MCI and ADRD participants.

CONCLUSION

Multimodal approaches may improve recognition of MCI and ADRD. OCT has the potential to be a practical, non-invasive biomarker for ADRD providing a screening platform to quickly identify at-risk individuals for further clinical evaluation or research enrollment.

What older adults do with the results of dementia screening programs

Introduction

Alzheimer’s disease and related dementias (ADRD) and mild cognitive impairment (MCI) are often under-recognized in the community. MCI/ADRD screening could offer benefits such as early treatment, research participation, lifestyle modification, and advanced care planning. To date, there are no clear guidelines regarding the benefits vs. harms of dementia screening or whether a dementia screening program could be successful.

Methods

A community-based study was conducted to evaluate an MCI/ADRD screening program and determine what older adults would do with the information. Measures of cognition, physical health, functionality, and mood were collected. Participants met with a health professional, were given screening results with recommendations, and then contacted 60 days later to determine what was done with the results. Logistic regression models were used to build predictive models.

Results

Participants (n = 288) had a mean age of 71.5±8.3y, mean education of 13.3±4.8y, and were 70% female, 67% White, 26% African American, and 48% Hispanic. After 60 days, 75% of participants were re-contacted; 54% shared results with family, 33% shared results with health care providers (HCPs), and 52% initiated behavioral change. Among participants sharing results with HCPs, 51% reported HCPs did not follow-up on the results, and 18% that HCPs did not show any interest in the screening visit or its results. Predictors of sharing results with HCPs were elevated hemoglobin A1C (OR = 1.85;95%CI:1.19–2.88), uncontrolled hypertension (OR = 2.73;95%CI:1.09–6.83), and mobility issues (OR = 2.43;95%CI: 1.93–5.54). Participant behavioral changes included lifestyle modification (58%), social engagement (10%), cognitive stimulation (5%), and advanced care planning (4%). The most significant predictors of sharing with family were better overall mental health (OR = 0.19; 95%CI: 0.06–0.59) and better physical function (OR = 0.38; 95%CI: 0.17–0.81).

Discussion

MCI/ADRD screening was well-received by a diverse community sample. Participants showed interest in sharing the results with their family and HCPs and many attempted behavioral change. While HCPs did not always act on screening results, 25% ordered further testing and evaluation. Efforts need to be directed toward (1) increasing self-efficacy of older adults to discuss screening results with their HCPs, and (2) educating HCPs on the value of early detection of MCI/ADRD. Community dementia screening programs can increase MCI/ADRD detection and improve patient-centered outcomes and medical decision-making.

Intention to Be Screened for Alzheimer's Disease in Nondemented Older Adults: Integrated Behavioral Model and Self-Efficacy as Mediation Effect

The study explored factors associated with intention to be screened for Alzheimer's disease (AD). The study also examined whether self-efficacy mediates the relationship between knowledge about screening and the intention to be screened for AD. A population-based, random-digit dialing survey was performed and 1,043 responses were collected from a sample of nondemented persons (50 years or older) living in urban, suburban, and rural areas in a Midwestern state. The findings showed that participants who were younger and who had higher levels of (a) perceived benefits and barriers, (b) social support, and (c) self-efficacy reported higher levels of intention to be screened for AD. Older adults with positive life orientation reported greater intention to be screened for AD, whereas depressed participants were more likely to report a plan to be screened for AD. Self-efficacy mediated the relationship between knowledge about screening and intention to be screened. Older adults were more likely to report intention to be screened when they had positive attitudes about the screen and believed that they could receive the screen. The intention to be screened for AD could serve public awareness by defining effective ways to assist older adults to seek a cognitive screen.

Physician Practice Patterns Associated with Diagnostic Evaluation of Patients with Suspected Mild Cognitive Impairment and Alzheimer's Disease

The diagnostic process for patients presenting with cognitive decline and suspected dementia is complex. Physicians face challenges distinguishing between normal aging, mild cognitive impairment, Alzheimer's disease, and other dementias. Although there is some evidence for improving attitudes towards the importance of prompt diagnosis, there is limited information describing how physicians approach this diagnostic challenge in practice. This was explored in the present study. Across-sectional survey of primary care and specialist physicians, in 5 European countries, Canada, and the United States, was conducted. Participants were asked about their use of cognitive screening tools and diagnostic technologies, as well as the rationales and barriers for use. In total, 1365 physicians participated in the survey, 63% of whom were specialists. Most physicians stated they use objective cognitive tools to aid the early detection of suspected mild cognitive impairment or Alzheimer's disease in patients. The Mini-Mental State Examination was the most common tool used for initial screening; respondents cited speed and ease of use but noted its lack of specificity. Cerebrospinal fluid biomarker and amyloid positron emission tomography tests, respectively, had been used by only 26% and 32% of physicians in the preceding 6 months, although patterns of use varied across countries. The most commonly cited reasons for not ordering such tests were invasiveness (for cerebrospinal fluid biomarker testing) and cost (for amyloid positron emission tomography imaging). Data reported by physicians reveal differences in the approaches to the diagnostics process in Alzheimer's. A higher proportion of primary care physicians in the United States are routinely incorporating cognitive assessment tools into annual visits, but this is due to country differences in clinical practice. The value of screening tools and regular use could be discussed further with physicians; however, lack of specificity associated with cognitive tools and the investment required from patients and the healthcare system are limiting factors.

Using Informant and Performance Screening Methods to Detect Mild Cognitive Impairment and Dementia

Purpose of Review

Dementia detection in the community is challenging. The purpose of this paper is to review methods of dementia screening and provide a useable algorithm for screening for dementia a variety of clinical settings.

Recent Findings

In recent years, a number of brief performance and informant-based assessments have been developed and validated in research, clinical, and community samples. These assessments are now complemented by patient self-reports that afford the ability to detect subjective cognitive impairment.

Summary

An optimal approach to dementia screening is to combine performance, informant, and self-reports, many of which can be completed in the waiting room or by non-physician staff prior to the start of the office visit. This diverse information may help inform the provider as to the presence or absence of a cognitive disorder, assist in staging the extent of the disorder, and help to develop a differential diagnosis and management plan.

General Practitioner Assessment of Cognition: use in primary care prior to memory clinic referral

Aims: To measure current and comparative frequencies of use of the General Practitioner Assessment of Cognition (GPCOG) scale in consecutive primary care referrals to a dedicated secondary care memory clinic. Methods: Over 6 months (January–June 2015), referral letters from primary care (n = 121) were examined for mention of GPCOG use. Results: The proportion of patients administered any cognitive screening instrument before referral was 41.3%, with 11.6% administered the GPCOG, a significant increase compared with prior cohorts. However, GPCOG was incorrectly used or documented in 29% of cases. Conclusion: GPCOG use is increasing in primary care settings, but training in its correct use and scoring may be required to ensure that its administration makes meaningful information available.

A Method to Differentiate Mild Cognitive Impairment and Alzheimer in MR Images using Eigen Value Descriptors

Automated analysis and differentiation of mild cognitive impairment and Alzheimer's condition using MR images is clinically significant in dementic disorder. Alzheimer's Disease (AD) is a fatal and common form of dementia that progressively affects the patients. Shape descriptors could better differentiate the morphological alterations of brain structures and aid in the development of prospective disease modifying therapies. Ventricle enlargement is considered as a significant biomarker in the AD diagnosis. In this work, a method has been proposed to differentiate MCI from the healthy normal and AD subjects using Laplace-Beltrami (LB) eigen value shape descriptors. Prior to this, Reaction Diffusion (RD) level set is used to segment the ventricles in MR images and the results are validated against the Ground Truth (GT). LB eigen values are infinite series of spectrum that describes the intrinsic geometry of objects. Most significant LB shape descriptors are identified and their performance is analysed using linear Support Vector Machine (SVM) classifier. Results show that, the RD level set is able to segment the ventricles. The segmented ventricles are found to have high correlation with GT. The eigen values in the LB spectrum could show distinction in the feature space better than the geometric features. High accuracy is observed in the classification results of linear SVM. The proposed automated system is able to distinctly separate the MCI from normal and AD subjects. Thus this pipeline of work seems to be clinically significant in the automated analysis of dementic subjects.