A 4-Item Case-Finding Tool to Detect Dementia in Older Persons

Early Diagnosis of Mild Cognitive Impairment due to Alzheimer's Disease Using a Composite of MemTrax and Blood Biomarkers

BACKGROUND

Accessible measurements for the early detection of mild cognitive impairment (MCI) due to Alzheimer's disease (AD) are urgently needed to address the increasing prevalence of AD.

OBJECTIVE

To determine the benefits of a composite MemTrax Memory Test and AD-related blood biomarker assessment for the early detection of MCI-AD in non-specialty clinics.

METHODS

The MemTrax Memory Test and Montreal Cognitive Assessment were administered to 99 healthy seniors with normal cognitive function and 101 patients with MCI-AD; clinical manifestation and peripheral blood samples were collected. We evaluated correlations between the MemTrax Memory Test and blood biomarkers using Spearman's rank correlation analyses and then built discrimination models using various machine learning approaches that combined the MemTrax Memory Test and blood biomarker results. The models' performances were assessed according to the areas under the receiver operating characteristic curve.

RESULTS

The MemTrax Memory Test and Montreal Cognitive Assessment areas under the curve for differentiating patients with MCI-AD from the healthy controls were similar. The MemTrax Memory Test strongly correlated with phosphorylated tau 181 and amyloid-β 42/40. The area under the curve for the best composite MemTrax Memory Test and blood biomarker model was 0.975 (95% confidence interval: 0.950-0.999).

CONCLUSION

Combining MemTrax Memory Test and blood biomarker results is a promising new technique for the early detection of MCI-AD.

Subjective cognitive decline, APOE e4 allele, and the risk of neurocognitive disorders: Age- and sex-stratified cohort study

OBJECTIVE

Subjective cognitive decline and APOE e4 allele (APOE4) are known predictors of mild cognitive impairment and dementia (mild cognitive impairment/dementia), with recent evidence showing interaction between subjective cognitive decline and APOE4 in amplifying the risk of mild cognitive impairment/dementia. However, the literature is unclear whether the interaction effect is seen across various age and sex strata. This study examined the interaction between subjective cognitive decline and APOE4-across different age and sex strata-on the risk of mild cognitive impairment/dementia.

METHODS

This cohort study included 16,221 participants aged ⩾50 years and had normal cognition at baseline. Participants were evaluated for subjective cognitive decline and APOE4 at baseline, and followed-up almost annually for mild cognitive impairment/dementia (median follow-up = 4.5 years). Interaction effects were examined in Cox regression using Relative Excess Risk due to Interaction, stratified by age (⩽70 vs >70 years) and sex.

RESULTS

Subjective cognitive decline and APOE4 were independently associated with mild cognitive impairment/dementia (hazard ratio: 1.4-1.8), with the highest risk when subjective cognitive decline and APOE4 co-occurred (hazard ratio: 2.6). APOE4 amplified the association between subjective cognitive decline and mild cognitive impairment/dementia in older women (Relative Excess Risk due to Interaction 1.0; 95% confidence interval = [0.3, 1.6]), but not in other age or sex strata. Among older women, half of them developed mild cognitive impairment/dementia by 12.1 years in the absence of subjective cognitive decline or APOE4. This duration shortened to 8.1-10.3 years in the presence of either subjective cognitive decline or APOE4, and to 4.4 years in the presence of both subjective cognitive decline and APOE4. Interaction effect among older women remained consistent when alternate outcomes were used (i.e. mild cognitive impairment and dementia due to Alzheimer's disease; dementia; and Alzheimer's dementia) (Relative Excess Risk due to Interaction 1.2-2.5).

CONCLUSIONS

APOE4 amplifies the association between subjective cognitive decline and neurocognitive disorders in older women, with the findings suggesting the need for further research to delineate underlying neurobiology. APOE4 may potentially have a role in facilitating further risk stratification of older women with subjective cognitive decline in clinical practice.

Neuropsychiatric symptoms in early stage of Alzheimer's and non-Alzheimer's dementia, and the risk of progression to severe dementia

BACKGROUND

Neuropsychiatric symptoms (NPSs) in early dementia have been suggested to predict a higher risk of dementia progression. However, the literature is not yet clear whether the risk is similar across Alzheimer's dementia (AD) and non-Alzheimer's dementia (non-AD), as well as across different NPSs. This study examined the association between NPSs in early dementia and the risk of progression to severe dementia, specifically in AD and non-AD, as well as across various NPSs.

METHOD

This cohort study included 7,594 participants who were ≥65 years and had early dementia (global Clinical Dementia Rating [CDR] = 1). Participants completed Neuropsychiatric-Inventory-Questionnaire at baseline and were followed-up almost annually for progression to severe dementia (global CDR = 3) (median follow-up = 3.5 years; interquartile range = 2.1-5.9 years). Cox regression was used to examine progression risk, stratified by AD and non-AD.

RESULTS

The presence of NPSs was associated with risk of progression to severe dementia, but primarily in AD (HR 1.4, 95% confidence interval [CI]: 1.1-1.6) and not in non-AD (HR 0.9, 95% CI: 0.5-1.5). When comparing across various NPSs, seven NPSs in AD were associated with disease progression, and they were depression, anxiety, apathy, delusions, hallucinations, irritability and motor disturbance (HR 1.2-1.6). In contrast, only hallucinations and delusions were associated with disease progression in non-AD (HR 1.7-1.9).

CONCLUSIONS

NPSs in early dementia-especially among individuals with AD-can be useful prognostic markers of disease progression. They may inform discussion on advanced care planning and prompt clinical review to incorporate evidence-based interventions that may address disease progression.

Trajectories of subjective cognitive decline, and the risk of mild cognitive impairment and dementia

BACKGROUND

In cognitively normal individuals, subjective cognitive decline (SCD) has been reported to predict MCI and dementia (MCI/dementia). However, prior studies mostly captured SCD at single time-points without considering the longitudinal course of SCD. This study examined whether the trajectories of SCD provide any added information-beyond one-time assessments of SCD-on the risk of MCI/dementia.

METHODS

This cohort study included 5661 participants from the Alzheimer's Disease Centers across the USA, who were ≥ 50 years and had normal cognition in the first-four annual visits (year 1 to year 4). The participants were evaluated for SCD in the first-four annual visits (year 1 to year 4), and followed-up almost annually (year 4 up to year 14) for incident MCI/dementia. SCD trajectories (as identified from latent-class-growth-curve-analysis) were included in Cox regression to estimate their risks of MCI/dementia, with analyses further stratified by age (< 75 years versus ≥ 75 years; based on median-split).

RESULTS

Compared to those without SCD (in the first-four annual visits), Intermittent SCD (i.e., reported in 1-2 of the first-four annual visits) predicted a higher risk (HR 1.4) and Persistent SCD (i.e., reported in 3-4 of the first-four annual visits) predicted the highest risk (HR 2.2), with the results remaining significant even after adjusting for baseline SCD. Age-stratified analysis revealed that the risk associated with Intermittent SCD was only present in older individuals, while risk related to Persistent SCD was consistently present across the younger and older age groups. Age compounded the effects of the trajectories, whereby older individuals with Persistent SCD had > 75% probability of developing MCI/dementia by 10 years, in contrast to < 25% probability by 10 years in younger individuals with No SCD.

CONCLUSIONS

The findings demonstrate the utility of SCD trajectories-especially when used in combination with age strata-in identifying high-risk populations for preventive interventions and trials. They also suggest a potential modification in the current SCD criteria, with the inclusion of "persistent SCD over several years" as a feature of SCD plus.

Active case finding of dementia in ambulatory care settings: a comparison of three strategies

BACKGROUND AND PURPOSE

To reduce the diagnostic gap of dementia, three strategies can be employed for case finding of cognitive impairment in ambulatory care settings, namely using informant report, brief cognitive test or a combination of informant report and brief cognitive test. The right strategy to adopt across different healthcare settings remains unclear. This diagnostic study compared the performance of the three strategies for detecting dementia (primary aim), as well as for detecting both mild cognitive impairment (MCI) and dementia (secondary aim).

METHODS

Participants aged ≥65 years (n = 11 057) were recruited from Alzheimer's Disease Centers across the USA. Participants provided data on an informant report (Functional Activities Questionnaire), brief cognitive test (four-item short variant of Montreal Cognitive Assessment) and a combined measure with informant report and brief cognitive test (sum of Functional Activities Questionnaire and Montreal Cognitive Assessment short variant). They also received standardized assessments (clinical history, physical examination and neuropsychological testing) to diagnose MCI and dementia. Areas under the receiver operating characteristic curve (AUCs) of the three strategies were compared using the DeLong method, with AUC > 90% indicating excellent performance.

RESULTS

All three strategies had excellent performance in detecting dementia, although informant report [AUC, 95.9%; 95% confidence intervals (CI), 95.4-96.3%] was significantly better than brief cognitive test (AUC, 93.0%; 95% CI, 92.4-93.6%) and the combined measure had the best performance (AUC, 97.0%; 95% CI, 96.7-97.4%). However, to detect both MCI and dementia, only the combined measure had excellent performance (AUC, 93.0%; 95% CI, 92.5-93.4%), whereas stand-alone informant report or brief cognitive test performed suboptimally (AUC < 90%). Performance of the three strategies was not affected by participants' age, educational attainment or underlying prevalence of MCI and dementia.

CONCLUSIONS

For case finding of dementia in ambulatory care settings, informant reports would suffice as first-line measures and brief cognitive tests may optionally be added on, in services with available resources, to further improve the accuracy of detection. For case finding of both MCI and dementia, a combination of informant reports and brief cognitive tests remains the most appropriate strategy.

Subjective cognitive decline, anxiety symptoms, and the risk of mild cognitive impairment and dementia

BACKGROUND

Subjective cognitive decline (SCD) and anxiety symptoms both predict neurocognitive disorders, but the two correlate strongly with each other. It is unclear whether they reflect two independent disease processes in the development of neurocognitive disorders and hence deserve separate attention. This cohort study examined whether SCD and anxiety symptoms demonstrate independent risks of mild cognitive disorder and dementia (MCI/dementia).

METHODS

The study included 14,066 participants aged ≥ 50 years and diagnosed with normal cognition at baseline, recruited from Alzheimer's Disease Centers across the USA. The participants were evaluated for SCD and anxiety symptoms at baseline and followed up almost annually for incident MCI/dementia (median follow-up 4.5 years; interquartile range 2.2-7.7 years). SCD and anxiety symptoms were included in Cox regression to investigate their independent risks of MCI/dementia.

RESULTS

SCD and anxiety symptoms demonstrated independent risks of MCI/dementia, with HR 1.9 (95% CI 1.7-2.1) and 1.3 (95% CI 1.2-1.5), respectively. Co-occurring SCD and anxiety symptoms demonstrated the highest risk (HR 2.4, 95% CI 1.9-2.9)-participants in this group had a 25% probability of developing MCI/dementia by 3.1 years (95% 2.4-3.7), compared to 8.2 years among those without SCD or anxiety (95% CI 7.9-8.6). The results remained robust even in the sensitivity analyses that took into account symptom severity and consistency of symptoms in the first 2 annual visits.

CONCLUSIONS

The findings suggest that clinicians should not dismiss one over the other when patients present with both SCD and anxiety and that both constructs may potentially be useful to identify high-risk populations for preventive interventions and trials. The findings also point to the need for further research to clarify on the neurobiological distinctions between SCD and anxiety symptoms, which may potentially enrich our understanding on the pathogenesis of neurocognitive disorders.

Recommendations of the 5th Canadian Consensus Conference on the diagnosis and treatment of dementia

Since 1989, four Canadian Consensus Conferences on the Diagnosis and Treatment of Dementia (CCCDTD) have provided evidence-based dementia guidelines for Canadian clinicians and researchers. We present the results of the 5th CCCDTD, which convened in October 2019, to address topics chosen by the steering committee to reflect advances in the field, and build on previous guidelines. Topics included: (1) utility of the National Institute on Aging research framework for clinical Alzheimer's disease (AD) diagnosis; (2) updating diagnostic criteria for vascular cognitive impairment, and its management; (3) dementia case finding and detection; (4) neuroimaging and fluid biomarkers in diagnosis; (5) use of non-cognitive markers of dementia for better dementia detection; (6) risk reduction/prevention; (7) psychosocial and non-pharmacological interventions; and (8) deprescription of medications used to treat dementia. We hope the guidelines are useful for clinicians, researchers, policy makers, and the lay public, to inform a current and evidence-based approach to dementia.

Comparative Study of Two Short-Form Versions of the Montreal Cognitive Assessment for Screening of Post-Stroke Cognitive Impairment in a Chinese Population

Purpose

Cognitive impairment (CI) is one of the most significant post-stroke complications. The Montreal Cognitive Assessment (MoCA) is widely applied to the early screening of post-stroke CI (PSCI), and has good sensitivity and specificity, but needs a long time to administer. Clinicians and researchers need shorter, more effective cognitive testing tools. The purpose of this study was to detect the sensitivity and specificity of two different short-form versions of the MoCA (SF-MoCA) for screening of PSCI in a Chinese population.

Methods

A total of 2,989 stroke participants were included from 14 hospitals in northern and southern China between June 2011 and September 2013. The sensitivity and specificity of the two SF-MoCA versions were compared.

Results

Using an MoCA score <26 as the critical value, the National Institute of Neurological Disease and Stroke–Canadian Stroke Network SF-MoCA showed sensitivity of 91% and specificity of 63% (PPV 71%, BPV 87%) with scores ≤10 points. The sensitivity and specificity of the Bocti SF-MoCA were 92% and 69% (PPV 75%, BPV 89%) with scores ≤7, respectively. The area under the curve was 0.885 (95% CI 0.873–0.897) and 0.912 (95% CI 0.902–0.922), respectively.

Conclusion

The Bocti SF-MoCA can be used as a briefer and more effective screening tool for PSCI in Chinese.

Neuropsychiatric symptoms in cognitively normal older persons, and the association with Alzheimer's and non-Alzheimer's dementia

Background

Neuropsychiatric symptoms (NPS) have been reported to be useful in predicting incident dementia among cognitively normal older persons. However, the literature has not been conclusive on the differential utilities of the various NPS in predicting the subtypes of dementia. This study compared the risks of Alzheimer’s and non-Alzheimer’s dementia associated with the various NPS, among cognitively normal older persons.

Methods

This cohort study included 12,452 participants from the Alzheimer’s Disease Centers across USA, who were ≥ 60 years and had normal cognition at baseline. Participants completed the Neuropsychiatric Inventory-Questionnaire at baseline and were followed up almost annually for incident dementia (median follow-up = 4.7 years). Symptom clusters of NPS—as identified from exploratory and confirmatory factor-analyses—were included in the Cox regression to investigate their associations with incident dementia.

Results

The various NPS showed independent yet differential associations with incident dementia. Although psychotic symptoms were rarely endorsed by the participants, they predicted much higher risk of dementia (HR 3.6, 95% CI 2.0–6.4) than affective symptoms (HR 1.5, 95% CI 1.2–1.8) or agitation symptoms (HR 1.6, 95% CI 1.3–2.1). Psychotic symptoms predicted all dementia subtypes, while affective and agitation symptoms differentially predicted some subtypes. Across dementia subtypes, psychotic symptoms had relatively higher risk estimates than affective or agitation symptoms, with the risk estimates being particularly high in non-Alzheimer’s dementia.

Conclusions

Among cognitively normal individuals, the presence of NPS may warrant greater clinical vigilance as precursors to dementia and its subtypes. The findings highlight the need for further research to enrich our understanding on the neurobiological links between various NPS and dementia subtypes. They may also change the clinical approach in managing late-life psychotic symptoms, requiring a greater emphasis on dementia surveillance in the diagnostic criteria of late-life psychotic disorders.