Cognitive Impairment Precedes and Predicts Functional Impairment in Mild Alzheimer's Disease

Experiences of older adults participating in dance exergames: A systematic review and meta-synthesis

BACKGROUND

Interventions to encourage adequate physical activity amongst older adults have had limited long-term success. Dancing and exergames, two beneficial and enjoyable physical activities for older adults, may make regular exercise more interesting and effective. Dance exergames are physical exercises that integrate sensory, cognitive, psychological, and physical functions by requiring users to interact with game scenarios through deliberate body motions and receive real-time feedback. They provide an inherently enjoyable gaming and workout experience, which may boost exercise adherence. However, little is known about older adults' experiences with dance exergames.

OBJECTIVE

To synthesise the qualitative experiences of older adults participating in dance exergames.

DESIGN

Systematic review and meta-synthesis.

METHODS

Dance exergame studies (peer-reviewed and grey literature) involving older adults in any setting published in English from inception to 17 August 2023 were included. Qualitative or mixed-method studies must use immersive or non-immersive virtual-reality platforms. PubMed, Scopus, CINAHL, The Cochrane Library, ProQuest Dissertations & Theses Global, Google Scholar, and reference lists of relevant studies and reviews were searched for eligible studies. The search strategy for Scopus was: (TITLE-ABS-KEY (danc*) AND TITLE-ABS-KEY (exergames OR exergame OR video AND games OR virtual AND reality) AND TITLE-ABS-KEY (older AND adults OR elderly OR seniors OR geriatrics)). Thematic synthesis by Thomas and Harden was used for meta-synthesis.

RESULTS

Eleven studies (n = 200 older adults) were included. Three themes and 14 subthemes were synthesised: 1) Dance exergames as dual-task training for physical, cognitive, and psychological well-being, 2) Concerns on usability issues, and 3) Possible enhancements of dance exergames. Older adults recognised that dance exergames could improve their physical, cognitive, and psychological well-being. Existing dance exergame systems had several usability issues. For example, some older adults were unfamiliar with using new technology and had trouble in navigating the game systems. The older adults also provided various suggestions for adaptation to their age group, such as ensuring a variety of dances, difficulty levels suited for older adults' cultural backgrounds, and physical and cognitive capabilities.

CONCLUSIONS

Dance exergames may be an attractive way to encourage older adults to exercise, but appropriate modifications are needed. When designing/selecting dance exergames for older persons, researchers, healthcare professionals, and senior care centres should consider using exergames that have simple designs, varied dances that are locally adapted, and appeal to a large proportion of older adults.

REGISTRATION

PROSPERO CRD42023395709.

Assessment of Efficacy and Safety of Zagotenemab: Results From PERISCOPE-ALZ, a Phase 2 Study in Early Symptomatic Alzheimer Disease

BACKGROUND AND OBJECTIVES

Zagotenemab (LY3303560), a monoclonal antibody that preferentially targets misfolded, extracellular, aggregated tau, was assessed in the PERISCOPE-ALZ phase 2 study to determine its ability to slow cognitive and functional decline relative to placebo in early symptomatic Alzheimer disease (AD).

METHODS

Participants were enrolled across 56 sites in North America and Japan. Key eligibility criteria included age of 60-85 years, Mini-Mental State Examination score of 20-28, and intermediate levels of brain tau on PET imaging. In this double-blind study, participants were equally randomized to 1,400 mg or 5,600 mg of zagotenemab, or placebo (IV infusion every 4 weeks for 100 weeks). The primary outcome was change on the Integrated AD Rating Scale (iADRS) assessed by a Bayesian Disease Progression model. Secondary measures include mixed model repeated measures analysis of additional cognitive and functional endpoints as well as biomarkers of AD pathology.

RESULTS

A total of 360 participants (mean age = 75.4 years; female = 52.8%) were randomized, and 218 completed the treatment period. Demographics and baseline characteristics were reasonably balanced among arms. The mean disease progression ratio (proportional decline in the treated vs placebo group) with 95% credible intervals for the iADRS was 1.10 (0.959-1.265) for the zagotenemab low-dose group and 1.05 (0.907-1.209) for the high-dose, where a ratio less than 1 favors the treatment group. Secondary clinical endpoint measures failed to show a drug-placebo difference in favor of zagotenemab. No treatment effect was demonstrated by flortaucipir PET, volumetric MRI, or neurofilament light chain (NfL) analyses. A dose-related increase in plasma phosphorylated tau181 and total tau was demonstrated. Zagotenemab treatment groups reported a higher incidence of adverse events (AEs) (85.1%) compared with the placebo group (74.6%). This difference was not attributable to any specific AE or category of AEs.

DISCUSSION

In participants with early symptomatic AD, zagotenemab failed to achieve significant slowing of clinical disease progression compared with placebo. Imaging biomarker and plasma NfL findings did not show evidence of pharmacodynamic activity or disease modification.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov: NCT03518073.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with early symptomatic AD, zagotenemab does not slow clinical disease progression.

Targets, trials and tribulations in Alzheimer therapeutics

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by abnormal accumulation of extracellular amyloid beta senile plaques and intracellular neurofibrillary tangles in the parts of the brain responsible for cognition. The therapeutic burden for the management of AD relies solely on cholinesterase inhibitors that provide only symptomatic relief. The urgent need for disease-modifying drugs has resulted in intensive research in this domain, which has led to better understanding of the disease pathology and identification of a plethora of new pathological targets. Currently, there are over a hundred and seventy clinical trials exploring disease modification, cognitive enhancement, and reduction of neuro-psychiatric complications. However, the path to developing safe and efficacious AD therapeutics has not been without challenges. Several clinical trials have been terminated in advanced stages due to lack of therapeutic translation or increased incidence of adverse events. This review presents an in-depth look at the various therapeutic targets of AD and the lessons learnt during their clinical assessment. Comprehensive understanding of the implication of modulating various aspects of Alzheimer brain pathology is crucial for development of drugs with potential to halt disease progression in Alzheimer therapeutics.

Do physical fitness and cognitive function mediate the relationship between basic activities of daily living and quality of life in older adults with dementia?

PURPOSE

Independence in activities of daily living (ADLs) is associated with quality of life (QoL) in individuals with dementia. However, the contribution of physical and cognitive functions to this relationship needs further examination. This study aims to examine the mediating effect of physical fitness and cognitive function in the relationship between independence in basic ADLs and QoL among older adults with dementia.

METHODS

This cross-sectional study included 107 older adults with dementia (74.8% women; age 78.21 ± 7.70 years). Independence in basic ADL and QoL were evaluated using the Barthel Index (BI) and QoL- Alzheimer's Disease Scale, respectively. The Alzheimer's Disease Assessment Scale-Cognitive Subscale and the Mini-Mental State Examination were applied to assess cognitive function. Physical fitness was evaluated using the 30-s chair stand, 2-min step and the Timed-Up and Go tests. A structural equation modelling (SEM) with bootstrapping estimation was conducted to determine the relationship between all variables.

RESULTS

Independence in basic ADL positively affected QoL and this association was mediated by physical fitness (β = 0.242, p = 0.011). No statistically significant results were observed when testing cognitive function as a mediator between BI and QoL (β = 0.009, p = 0.345).

CONCLUSIONS

Physical fitness (i.e., lower body strength, aerobic capacity, and mobility) plays a role in the relationship between basic ADL independence and QoL of older adults with dementia, reinforcing the need to improve and monitor these parameters throughout the disease progression. Future longitudinal studies should explore the temporal relationship between physical and cognitive function and its contribution to basic ADL independence and QoL.

Meaningful Clinical Changes in Alzheimer Disease Measured With the iADRS and Illustrated Using the Donanemab TRAILBLAZER-ALZ Study Findings

Purpose of Review

To provide relevant background of the Integrated Alzheimer's Disease Rating Scale (iADRS), with examples, to assist the reader with the interpretation of iADRS findings from the TRAILBLAZER-ALZ study.

Recent Findings

The iADRS is an integrated measure of global Alzheimer disease (AD) severity for use in the clinical trial environment. It provides a single score that captures commonalities across cognitive and functional ability domains, reflecting disease-related impairment, while minimizing noise not related to disease progression that may exist within each domain. In AD, disease-modifying therapies (DMTs) are expected to slow the rate of clinical decline, changing the trajectory of disease progression. The overall percent slowing of disease progression with treatment is a more informative outcome of effect than absolute point differences between treatment and placebo groups at any given time point because the latter is influenced by treatment period and disease severity. The TRAILBLAZER-ALZ trial was a phase 2 study designed to evaluate the safety and efficacy of donanemab in participants with early symptomatic AD; the primary outcome measure was the change from baseline to 76 weeks on the iADRS. In the TRAILBLAZER-ALZ study, donanemab slowed disease progression by 32% at 18 months (p = 0.04 vs placebo), demonstrating clinical efficacy. At the patient level, one can assess whether the DMT effect is clinically meaningful by estimating the threshold of change consistent with clinically meaningful worsening; based on the TRAILBLAZER-ALZ findings, treatment with donanemab would delay reaching this threshold by approximately 6 months.

Summary

The iADRS is capable of accurately describing clinical changes associated with disease progression and detecting treatment effects and is an effective assessment tool for use in clinical trials of individuals with early symptomatic AD.

Why a clinical trial is as good as its outcome measure: A framework for the selection and use of cognitive outcome measures for clinical trials of Alzheimer's disease

A crucial aspect of any clinical trial is using the right outcome measure to assess treatment efficacy. Compared to the rapidly evolved understanding and measurement of pathophysiology in preclinical and early symptomatic stages of Alzheimer's disease (AD), relatively less progress has been made in the evolution of clinical outcome assessments (COAs) for those stages. The current paper aims to provide a benchmark for the design and evaluation of COAs for use in early AD trials. We discuss lessons learned on capturing cognitive changes in predementia stages of AD, including challenges when validating novel COAs for those early stages and necessary evidence for their implementation in clinical trials. Moving forward, we propose a multi-step framework to advance the use of more effective COAs to assess clinically meaningful changes in early AD, which will hopefully contribute to the much-needed consensus around more appropriate outcome measures to assess clinical efficacy of putative treatments. HIGHLIGHTS: We discuss lessons learned on capturing cognitive changes in predementia stages of AD. We propose a framework for the design and evaluation of performance based cognitive tests for use in early AD trials. We provide recommendations to facilitate the implementation of more effective cognitive outcome measures in AD trials.

Neurodegenerative Diseases: From Dysproteostasis, Altered Calcium Signalosome to Selective Neuronal Vulnerability to AAV-Mediated Gene Therapy

Despite intense research into the multifaceted etiology of neurodegenerative diseases (ND), they remain incurable. Here we provide a brief overview of several major ND and explore novel therapeutic approaches. Although the cause (s) of ND are not fully understood, the accumulation of misfolded/aggregated proteins in the brain is a common pathological feature. This aggregation may initiate disruption of Ca⁺⁺ signaling, which is an early pathological event leading to altered dendritic structure, neuronal dysfunction, and cell death. Presently, ND gene therapies remain unidimensional, elusive, and limited to modifying one pathological feature while ignoring others. Considering the complexity of signaling cascades in ND, we discuss emerging therapeutic concepts and suggest that deciphering the molecular mechanisms involved in dendritic pathology may broaden the phenotypic spectrum of ND treatment. An innovative multiplexed gene transfer strategy that employs silencing and/or over-expressing multiple effectors could preserve vulnerable neurons before they are lost. Such therapeutic approaches may extend brain health span and ameliorate burdensome chronic disease states.

The utilization of a nurse-led clinic by older people with cognitive complaints: Do they follow our advice?

AIM

Cognitive assessment services were found to be beneficial to older people with cognitive complaints but information is limited on adherence to the recommendations provided. This study aimed to identify predictors of clients' adherence to nursing recommendations after attending a community-based nurse-led cognitive assessment service in Hong Kong.

METHODS

A cross-sectional design was adopted. We analysed a dataset routinely collected from clients attending the services between January 2012 and January 2018. Multiple regression analyses were conducted to identify predictors (demographics, functional health status and cognitive performance) of the clients' adherence. Their satisfaction with the services was also examined.

RESULTS

Two hundred and twenty-three clients attended the clinic. Of the 133 who completed the telephone follow-up at the 6 months postconsultation, 44.1% did not adhere to the recommendations. Clients with a higher Clinical Dementia Rating (OR = 4.17), lower Clock Drawing Test score (OR = 1.13) and lower education level (OR = 0.91) were found to be less likely to adhere to the nursing recommendations. Ninety-six percent (190/198) were satisfied with the overall services.

CONCLUSION

Cognitive assessment services in nurse-led clinics could provide a self-referred service for older people with cognitive complaints. However, low adherence to nursing recommendations was found among clients with poorer cognitive functions and lower education levels.

Access to Disease-Modifying Alzheimer's Therapies: Addressing Possible Challenges Using Innovative Payment Models

OBJECTIVES

Aduhelm is the first approved disease-modifying therapies (DMT) for Alzheimer disease (AD). Nevertheless, under current payment models, AD DMTs-especially because they treat broader populations-will pose challenges to patient access since costs may accrue sooner than benefits do. New payment approaches may be needed to address this difference in timing.

METHODS

We use the Future Elderly Model that draws on nationally representative data sets such as the Health and Retirement Study to estimate the potential benefits because of hypothetical AD DMTs in 4 stylized treatment scenarios for patients with mild cognitive impairment or mild AD, and develop a payment model to estimate the accrual of net costs and benefits to private and public payers.

RESULTS

The modeled AD DMTs result in clinical benefit of 0.30 to 0.55 quality-adjusted life-years gained per patient in the baseline treatment scenario and 0.13 to 0.24 quality-adjusted life-years gained per patient in the least optimistic scenario. Private payers may observe a net loss in patients at the age of 61 to 65 years under the status quo (payment upon treatment). Constant and deferred installment payment models resolve this issue.

CONCLUSIONS

Innovative payment solutions, such as installment payments, may be required to address misaligned incentives that AD DMTs may create among patients younger than the age of 65 years and may help address concerns about the timing and magnitude of costs and benefits accrued to private payers.

A Novel Virtual Reality Assessment of Functional Cognition: Validation Study

Background

Cognitive deficits are present in several neuropsychiatric disorders, including Alzheimer disease, schizophrenia, and depression. Assessments used to measure cognition in these disorders are time-consuming, burdensome, and have low ecological validity. To address these limitations, we developed a novel virtual reality shopping task—VStore.

Objective

This study aims to establish the construct validity of VStore in relation to the established computerized cognitive battery, Cogstate, and explore its sensitivity to age-related cognitive decline.

Methods

A total of 142 healthy volunteers aged 20-79 years participated in the study. The main VStore outcomes included verbal recall of 12 grocery items, time to collect items, time to select items on a self-checkout machine, time to make the payment, time to order coffee, and total completion time. Construct validity was examined through a series of backward elimination regression models to establish which Cogstate tasks, measuring attention, processing speed, verbal and visual learning, working memory, executive function, and paired associate learning, in addition to age and technological familiarity, best predicted VStore performance. In addition, 2 ridge regression and 2 logistic regression models supplemented with receiver operating characteristic curves were built, with VStore outcomes in the first model and Cogstate outcomes in the second model entered as predictors of age and age cohorts, respectively.

Results

Overall VStore performance, as indexed by the total time spent completing the task, was best explained by Cogstate tasks measuring attention, working memory, paired associate learning, and age and technological familiarity, accounting for 47% of the variance. In addition, with λ=5.16, the ridge regression model selected 5 parameters for VStore when predicting age (mean squared error 185.80, SE 19.34), and with λ=9.49 for Cogstate, the model selected all 8 tasks (mean squared error 226.80, SE 23.48). Finally, VStore was found to be highly sensitive (87%) and specific (91.7%) to age cohorts, with 94.6% of the area under the receiver operating characteristic curve.

Conclusions

Our findings suggest that VStore is a promising assessment that engages standard cognitive domains and is sensitive to age-related cognitive decline.

Remote self-administration of digital cognitive tests using the Brief Assessment of Cognition: Feasibility, reliability, and sensitivity to subjective cognitive decline

Cognitive impairment is a common and pervasive feature of etiologically diverse disorders of the central nervous system, and a target indication for a growing number of symptomatic and disease modifying drugs. Remotely acquired digital endpoints have been recognized for their potential in providing frequent, real-time monitoring of cognition, but their ultimate value will be determined by the reliability and sensitivity of measurement in the populations of interest. To this end, we describe initial validation of remote self-administration of cognitive tests within a regulatorily compliant tablet-based platform. Participants were 61 older adults (age 55+), including 20 individuals with subjective cognitive decline (SCD). To allow comparison between remote (in-home) and site-based testing, participants completed 2 testing sessions 1 week apart. Results for three of four cognitive domains assessed demonstrated equivalence between remote and site-based tests, with high cross-modality ICCs (absolute agreement) for Symbol Coding (ICC = 0.75), Visuospatial Working Memory (ICC = 0.70) and Verbal Fluency (ICC > 0.73). Group differences in these domains were significant and reflected sensitivity to objective cognitive impairment in the SCD group for both remote and site-based testing (p < 0.05). In contrast, performance on tests of verbal episodic memory suggested inflated performance during unmonitored testing and indicate reliable use of remote cognitive assessments may depend on the construct, as well as the population being tested.

Past, present and future of therapeutic strategies against amyloid-β peptides in Alzheimer's disease: a systematic review

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease in ageing, affecting around 46 million people worldwide but few treatments are currently available. The etiology of AD is still puzzling, and new drugs development and clinical trials have high failure rates. Urgent outline of an integral (multi-target) and effective treatment of AD is needed. Accumulation of amyloid-β (Aβ) peptides is considered one of the fundamental neuropathological pillars of the disease, and its dyshomeostasis has shown a crucial role in AD onset. Therefore, many amyloid-targeted therapies have been investigated. Here, we will systematically review recent (from 2014) investigational, follow-up and review studies focused on anti-amyloid strategies to summarize and analyze their current clinical potential. Combination of anti-Aβ therapies with new developing early detection biomarkers and other therapeutic agents acting on early functional AD changes will be highlighted in this review. Near-term approval seems likely for several drugs acting against Aβ, with recent FDA approval of a monoclonal anti-Aβ oligomers antibody -aducanumab- raising hopes and controversies. We conclude that, development of oligomer-epitope specific Aβ treatment and implementation of multiple improved biomarkers and risk prediction methods allowing early detection, together with therapies acting on other factors such as hyperexcitability in early AD, could be the key to slowing this global pandemic.

Contribution of a multicomponent intervention on functional capacity and independence on activities of daily living in individuals with neurocognitive disorder

BACKGROUND

To examine the effects of a 6-month multicomponent (MT) exercise intervention in the functional capacity and ability to independently perform activities of daily living (ADL) of individuals diagnosed with neurocognitive disorder (NCD).

METHODS

A quasi-experimental controlled trial with a parallel design study was conducted in multicentered community-based settings. Forty-three individuals (N Female: 30) were allocated to an exercise group (EG; N: 23; mean 75.09, SD = 5.54 years) or a control group (CG; N:20; mean 81.90, SD = 1.33 years). The EG engaged in a 6-month MT program (60-min sessions, twice a week). Exercise sessions were divided into a warm-up, specific training (e.g., coordination and balance, lower and upper body strength, and aerobics), and cool down. Lower body function, mobility, and gait speed were evaluated through Short Physical Performance Battery (SPPB), Timed-Up and Go test (TUG) and 6-Meter Walk test, respectively. The Barthel Index (BI) was administered to assess individuals' ADL independence. Evaluations were performed before and after the 6-month intervention.

RESULTS

Linear Mixed Models revealed a statistically significant interaction (time X group) effect factor on SPPB (B = 2.33, 95% CI: 1.39-3.28, p < 0.001), TUG (B = - 11.15, 95% CI: - 17.23 - - 5.06, p = 0.001), and 6-Meter Walk test (B = 0.17, 95% CI: 0.08-0.25, p < 0.001). No differences between groups or assessment moments were found in the ability of individuals to independently perform ADL.

CONCLUSIONS

The 6-month MT exercise intervention improves the functional capacity of older adults living with NCD.

TRIAL REGISTRATION

ClinicalTrials.gov - identifier number NCT04095962 ; retrospectively registered on 19 September 2019.

Dynamic reciprocal relationships between cognitive and functional declines along the Alzheimer's disease continuum in the prospective COGICARE study

BACKGROUND

Thoroughly understanding the temporal associations between cognitive and functional dimensions along the dementia process is fundamental to define preventive measures likely to delay the disease's onset. This work aimed to finely describe the trajectories of cognitive and functional declines, and assess their dynamic bidirectional relationships among subjects at different stages of the dementia process.

METHODS

We leveraged extensive repeated data of cognition and functional dependency from the French prospective COGICARE study, designed to better characterize the natural history of cognitive and functional declines around dementia diagnosis. Cognition was measured by the Mini-Mental State Examination, the Isaacs Set Test for verbal fluency, the Benton Visual Retention Test for visuo-spatial memory, and Trail Making Test Part B for executive functioning. Functional dependency was measured by basic and instrumental activities of daily living. The study included 102 cognitively normal, 123 mildly cognitively impaired, and 72 dementia cases with a median of 5 repeated visits over up to 57 months. We used a dynamic causal model which addresses the two essential issues in temporal associations assessment: focusing on intra-individual change and accounting for time.

RESULTS

Better cognitive abilities were associated with lower subsequent decline of the functional level among the three clinical stages with an intensification over time but no reciprocity of the association whatever the clinical status.

CONCLUSION

This work confirms that the progressive functional dependency could be induced by cognitive impairment. Subjects identified as early as possible with clinically significant cognitive impairments could benefit from preventive measures before the deterioration of activities of daily living and the appearance of dementia clinical signs.

Classification, Prediction, and Concordance of Cognitive and Functional Progression in Patients with Mild Cognitive Impairment in the United States: A Latent Class Analysis

Background:

Progression trajectories of patients with mild cognitive impairment (MCI) are currently not well understood.

Objective:

To classify patients with incident MCI into different latent classes of progression and identify predictors of progression class.

Methods:

Participants with incident MCI were identified from the US National Alzheimer’s Coordinating Center Uniform Data Set (09/2005-02/2019). Clinical Dementia Rating (CDR^®) Dementia Staging Instrument-Sum of Boxes (CDR-SB), Functional Activities Questionnaire (FAQ), and Mini-Mental State Examination (MMSE) score longitudinal trajectories from MCI diagnosis were fitted using growth mixture models. Predictors of progression class were identified using multivariate multinomial logistic regression models; odds ratios (ORs) and 95% confidence intervals (CIs) were reported.

Results:

In total, 21%, 22%, and 57% of participants (N = 830) experienced fast, slow, and no progression on CDR-SB, respectively; for FAQ, these figures were 14%, 23%, and 64%, respectively. CDR-SB and FAQ class membership was concordant for most participants (77%). Older age (≥86 versus≤70 years, OR [95% CI] = 5.26 [1.78–15.54]), one copy of APOE ɛ4 (1.94 [1.08–3.47]), higher baseline CDR-SB (2.46 [1.56–3.88]), lower baseline MMSE (0.85 [0.75–0.97]), and higher baseline FAQ (1.13 [1.02–1.26]) scores were significant predictors of fast progression versus no progression based on CDR-SB (all p < 0.05). Predictors of FAQ class membership were largely similar.

Conclusion:

Approximately a third of participants experienced progression based on CDR-SB or FAQ during the  4-year follow-up period. CDR-SB and FAQ class assignment were concordant for the vast majority of participants. Identified predictors may help the selection of patients at higher risk of progression in future trials.

Differences in Trajectories and Predictive Factors of Cognition over Time in a Sample of Cognitively Healthy Adults, in Zaragoza, Spain

Great inter-individual variability has been reported in the maintenance of cognitive function in aging. We examined this heterogeneity by modeling cognitive trajectories in a population-based longitudinal study of adults aged 55+ years. We hypothesized that (1) distinct classes of cognitive trajectories would be found, and (2) between-class differences in associated factors would be observed. The sample comprised 2403 cognitively healthy individuals from the Zaragoza Dementia and Depression (ZARADEMP) project, who had at least three measurements of the Mini-Mental State Examination (MMSE) in a 12-year follow-up. Longitudinal changes in cognitive functioning were modeled using growth mixture models (GMM) in the data. The best-fitting age-adjusted model showed 3 distinct trajectories, with 1-high-to-moderate (21.2% of participants), 2-moderate-stable (67.5%) and, 3-low-and-declining (9.9%) cognitive function over time, respectively. Compared with the reference 2-trajectory, the association of education and depression was significantly different in trajectories 1 and 3. Instrumental activities of daily living (iADLs) were only associated with the declining trajectory. This suggests that intervention strategies should be tailored specifically to individuals with different trajectories of cognitive aging, and intervention strategies designed to maintain cognitive function might be different from those to prevent decline. A stable cognitive performance ('successful cognitive aging') rather than a mild decline, might be more 'normal' than generally expected.

Slower Decline in Processing Speed Is Associated with Familial Longevity

INTRODUCTION

Cross-sectional analyses have associated familial longevity with better cognitive function and lower risk of cognitive impairment in comparison with individuals without familial longevity. The extent to which long-lived families also demonstrate slower rates of cognitive aging (i.e., change in cognition over time) is unknown. This study examined longitudinally collected data among 2 generations of the Long Life Family Study (LLFS) to compare rates of cognitive change across relatives and spouse controls.

METHODS

We analyzed change in 6 neuropsychological test scores collected approximately 8 years apart among LLFS family members (n = 3,972) versus spouse controls (n = 1,092) using a Bayesian hierarchical model that included age, years of follow-up, sex, education, generation, and field center and all possible pairwise interactions.

RESULTS

At a mean age of 88 years at enrollment in the older generation and 60 years in the younger generation, LLFS family members performed better than their spouses on the Digit Symbol Substitution Test (DSST) and the Logical Memory test. At follow-up, family members in the younger generation also showed slower decline than spouses on the DSST, whereas rates of change of Digit Span, fluency, and memory were similar between the 2 groups.

DISCUSSION/CONCLUSION

Individuals in families with longevity appear to have better cognitive performance than their spouses for cognitive processes including psychomotor processing, episodic memory, and retrieval. Additionally, they demonstrate longer cognitive health spans with a slower decline on a multifactorial test of processing speed, a task requiring the integration of processes including organized visual search, working and incidental memory, and graphomotor ability. Long-lived families may be a valuable cohort for studying resilience to cognitive aging.

Long-term functional decline of spontaneous intracerebral haemorrhage survivors

OBJECTIVE

To identify in patients who survived 6 months after a spontaneous intracerebral haemorrhage (ICH) baseline characteristics and new clinical events associated with functional decline.

METHODS

In a single-centre study, we prospectively included 6-month survivors with a modified Rankin Scale (mRS) score 0-3. We defined functional decline by a transition to mRS 4-5. We evaluated associations of baseline characteristics and new clinical events with functional decline, using univariate and multivariable models.

RESULTS

Of 560 patients, 174 (31%) had an mRS score 0-3 at 6 months. During a median follow-up of 9 years (IQR 8.1-9.5), 40 (23%) converted to mRS 4-5. Age, diabetes mellitus, ICH volume and higher mRS scores at 6 months were independently associated with functional decline. Among baseline MRI markers, presence of strictly lobar cerebral microbleeds (CMBs), and mixed lobar and deep CMBs were independently associated with functional decline. When new clinical events occurring during follow-up were added in multivariable models, age (cause-specific HR (CSHR): 1.07; 95% CI: 1.03 to 1.11), ICH volume (CSHR: 1.03; 95% CI: 1.01 to 1.06), mRS score at 6 months (CSHR per 1 point increase 1.61, 95% CI 1.07 to 2.43), occurrence of dementia (CSHR: 3.81, 95% CI: 1.78 to 8.16) and occurrence of any stroke (CSHR: 4.29, 95% CI: 1.80 to 10.22) remained independently associated with transition to mRS 4-5.

INTERPRETATION

Almost one-fourth of patients with spontaneous ICH developed a functional decline over time. Age, ICH volume, higher mRS score at 6 months and new clinical events after ICH are the major determinants.

Modelling Decline in Cognition to Decline in Function in Alzheimer's Disease

OBJECTIVES

The study aimed to evaluate and quantify the temporal link between cognitive and functional decline, and assess the impact of the apolipoprotein E4 (APOE-e4) genotype on Alzheimer's disease (AD) progression.

METHODS

A nonlinear mixed-effects Emax model was developed using longitudinal data from 659 patients with dementia due to AD sourced from the Alzheimer's disease neuroimaging initiative (ADNI) database. A cognitive decline model was first built using a cognitive subscale of the AD assessment scale (delayed word recall) as the endpoint, followed by a functional decline model, using the functional assessment questionnaire (FAQ) as the endpoint. Individual and population cognitive decline from the first model drove a functional decline in the second model. The impact of the APOE-e4 genotype status on the dynamics of AD progression was evaluated using the model.

RESULTS

Mixed-effects Emax models adequately quantified population average and individual disease trajectories. The model captured a higher initial cognitive impairment and final functional impairment in APOE-e4 carriers than non-carriers. The age at cognitive decline and diagnosis of dementia due to AD was significantly lower in APOE-e4 carriers than that of non-carriers. The average [standard deviation] time shift between cognitive and functional decline, i.e. the time span between half of the maximum cognitive decline and half of the maximum functional decline, was estimated as 1.5 [1.6] years.

CONCLUSION

The present analysis quantifies the temporal link between a cognitive and functional decline in AD progression at the population and individual level, and provides information about the potential benefits of pre-clinical AD treatments on both cognition and function.

Effect of Rotigotine vs Placebo on Cognitive Functions Among Patients With Mild to Moderate Alzheimer Disease: A Randomized Clinical Trial

IMPORTANCE

Impairment of dopaminergic transmission may contribute to cognitive dysfunction in Alzheimer disease (AD).

OBJECTIVE

To investigate whether therapy with dopaminergic agonists may affect cognitive functions in patients with AD.

DESIGN, SETTING, AND PARTICIPANTS

This phase 2, monocentric, randomized, double-blind, placebo-controlled trial was conducted in Italy. Patients with mild to moderate AD were enrolled between September 1, 2017, and December 31, 2018. Data were analyzed from July 1 to September 1, 2019.

INTERVENTIONS

A rotigotine 2 mg transdermal patch for 1 week followed by a 4 mg patch for 23 weeks (n = 47) or a placebo transdermal patch for 24 weeks (n = 47).

MAIN OUTCOMES AND MEASURES

The primary end point was change from baseline on the Alzheimer Disease Assessment Scale-Cognitive Subscale. Secondary end points were changes in Frontal Assessment Battery, Alzheimer Disease Cooperative Study-Activities of Daily Living, and Neuropsychiatric Inventory scores. Prefrontal cortex activity was evaluated by transcranial magnetic stimulation combined with electroencephalography.

RESULTS

Among 94 patients randomized (mean [SD] age, 73.9 [5.6] years; 58 [62%] women), 78 (83%) completed the study. Rotigotine, as compared with placebo, had no significant effect on the primary end point: estimated mean change in Alzheimer Disease Assessment Scale-Cognitive Subscale score was 2.92 (95% CI, 2.51-3.33) for the rotigotine group and 2.66 (95% CI, 2.31-3.01) for the placebo group. For the secondary outcomes, there were significant estimated mean changes between groups for Alzheimer Disease Cooperative Study-Activities of Daily Living score (-3.32 [95% CI, -4.02 to -2.62] for rotigotine and -7.24 [95% CI, -7.84 to -6.64] for placebo) and Frontal Assessment Battery score (0.48 [95% CI, 0.31 to 0.65] for rotigotine and -0.66 [95% CI, -0.80 to -0.52] for placebo). There was no longitudinal change in Neuropsychiatric Inventory scores (1.64 [95% CI, 1.06-2.22] for rotigotine and 1.26 [95% CI, 0.77-1.75] for placebo group). Neurophysiological analysis of electroencephalography results indicated that prefrontal cortical activity increased in rotigotine but not in the placebo group. Adverse events were more common in the rotigotine group, with 11 patients dropping out compared with 5 in the placebo group.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, rotigotine treatment did not significantly affect global cognition in patients with mild to moderate AD; however, improvement was observed in cognitive functions highly associated with the frontal lobe and in activities of daily living. These findings suggest that treatment with the dopaminergic agonist rotigotine may reduce symptoms associated with frontal lobe cognitive dysfunction and thus may delay the impairment of activities of daily living.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03250741.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

Maternal stressors and the developmental origins of neuropsychiatric risk

The maternal environment during pregnancy is critical for fetal development and perinatal perturbations can prime offspring disease risk. Here, we briefly review evidence linking two well-characterized maternal stressors - psychosocial stress and infection - to increased neuropsychiatric risk in offspring. In the current climate of increasing obesity and globalization of the Western-style diet, maternal overnutrition emerges as a pressing public health concern. We focus our attention on recent epidemiological and animal model evidence showing that, like psychosocial stress and infection, maternal overnutrition can also increase offspring neuropsychiatric risk. Using lessons learned from the psychosocial stress and infection literature, we discuss how altered maternal and placental physiology in the setting of overnutrition may contribute to abnormal fetal development and resulting neuropsychiatric outcomes. A better understanding of converging pathophysiological pathways shared between stressors may enable development of interventions against neuropsychiatric illnesses that may be beneficial across stressors.

Current Landscape of Late-Phase Clinical Trials for Alzheimer's Disease: Comparing Regional Variation Between Subjects in Japan and North America

INTRODUCTION

Over the last few decades, numerous late-phase multi-regional clinical trials have been conducted to develop a novel treatment for Alzheimer's disease (AD), with no effective results.

OBJECTIVE

To inform the design and interpretation of future clinical trials, the aim of this study was first to examine the current landscape of late-phase clinical trials to determine key study design characteristics, and then assess the regional variation between Japan and North America for the most utilized clinical efficacy endpoint in the most targeted stage of the disease.

METHODS

The study design and the mechanism of action of the interventional drugs tested in the late-phase clinical trials initiated in the last 5 years (2014-2018) were assessed based on the records in ClinicalTrials.gov database. The regional variation of the most utilized clinical efficacy endpoint in the most targeted population was assessed using data from two similarly designed observational studies conducted in Japan (Japanese Alzheimer's Disease Neuroimaging Initiative, J-ADNI) and North America (Alzheimer's Disease Neuroimaging Initiative, ADNI). For the most utilized clinical efficacy endpoint, the change from baseline (CFB) at Month 6, Year 1 and Year 2 was estimated using the growth curve model with a random intercept and slope, including gender as a fixed factor and age, apolipoprotein E ε4 genotype and years of education as covariates.

RESULTS

Of 48 Phase III trials that were initiated during the study period, 25 were disease-modifying treatment trials in which individuals with early AD were the most studied (56%) and Clinical Dementia Rating-Sum of Boxes (CDR-SB) was the most frequently utilized primary clinical efficacy endpoint (64%). The baseline characteristics of the early AD population between J-ADNI and ADNI were generally comparable, except for years of education. When comparing CDR-SB in early AD, J-ADNI had generally better baseline scores and the overall progression was similar (CFB at Year 2, ADNI 2.7 and J-ADNI 2.3, p = 0.190), despite slower progression in functional domains (CFB at Year 2, ADNI 1.4 and J-ADNI 1.0, p = 0.031).

CONCLUSION

Over the years, the target population has shifted toward early stage of the disease, wherein the clinical progression is slower and difficult to measure. Moreover, our results suggest that regional variation could have an impact on functional measurements due to cultural differences in pivotal clinical trials. Therefore, caution should be exercised according to the characteristics of the endpoint used.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Can deficits in functional capacity and practical judgment indicate cognitive impairment in older adults?

Neuropsychological literature has demonstrated a significant relationship between cognitive decline and functional capacity, but the directionality of this relationship is still not well understood. Further, the construct of practical judgment has been linked to both cognitive impairment and functional capacity, but these associations are still under-researched. Moreover, few studies to date have examined the relationships among all three constructs utilizing performance-based, ecologically valid and psychometrically sound measures. The present study aimed to address this gap in published literature and investigated whether a practical judgment and functional capacity can help differentiate individuals with cognitive dysfunction from those without. Participants were 270 community-dwelling individuals aged 56-95 years referred for neuropsychological evaluation in an outpatient setting. Bivariate correlations revealed moderate to strong relationships among the three studied variables. Additionally, logistic regression analysis indicated that ability to make sound practical judgments and ability to perform instrumental activities of daily living (IADL) can be used as indicators of cognitive impairment. The clinical implications of these findings are discussed.

Temporal precedence of cognitive function and functional abilities: A latent difference score model of the Chinese community-dwelling elders

OBJECTIVES

Little research has explored how cognitive function and activities of daily living (ADL) affect each other over time. In addition, no current finding provides a clear hint to the temporal precedence between them. The present study tries to address these limitations of prior studies by utilizing a longitudinal data and advanced statistical modeling.

METHODS

This study analyzed the data from the China Health and Retirement Longitudinal Study (CHARLS), a prospective observational study performed every 2 years for a total of three waves between 2011 and 2015 using a multistage probability sampling. Cognitive function was measured on the basis of three aspects of cognitive performance. Functional abilities were assessed using six types of activities of ADL and five types of instrumental ADL (IADL). Latent difference score modeling was employed to investigate the temporal precedence between cognitive function and ADL.

RESULTS

The best fitting model indicates poor cognitive function precede worsening in ADL function, whereas the current findings did not support that poor ADL predate the cognition decline or reciprocal influence hypotheses.

CONCLUSIONS

The elderly with poor cognitive function may be more vulnerable to deterioration in ADL. Findings underscore the importance of early screening for cognitive function among the elderly as the key strategy to prevent further ADL impairment and keep independence.

Relationships between Cognition and Activities of Daily Living in Alzheimer's Disease During a 5-Year Follow-Up: ALSOVA Study

BACKGROUND

Impaired cognition and activities of daily living (ADL) are core symptoms of Alzheimer's disease (AD), but their relationship is unclear.

OBJECTIVES

To explore relationships between cognitive domains and functional ability during 5-year follow-up in persons with AD.

METHODS

We analyzed ALSOVA study data from 236 individuals with very mild or mild AD at baseline. The CERAD Neuropsychological Battery (CERAD-NB) was used as a cognitive measure and Alzheimer's Disease Cooperative Study ADL (ADCS-ADL) as a functional measure, analyzing the IADL and BADL sub-scores separately. Annual regression models and linear mixed-effect models (LMMs) covering a 5-year follow-up period were used.

RESULTS

Annually, the CERAD-NB total and especially Verbal Fluency, Clock Drawing, and Constructional Praxis were associated with the total ADCS-ADL and IADL scores increasingly yet modestly, and to a lesser extent the BADL score. In the LMMs, the same measures and MMSE were associated with ADL.

CONCLUSION

Measures of executive function and visuoconstructive skills appear to be associated with caregiver-interview based ADL measure during the progression of AD.

The oral health status of residents with different cognitive and dental-related functions in three North Carolina assisted living facilities

INTRODUCTION

The aim of the study was to describe the oral health status of persons with different cognition and dental-related functions (DRFs).

METHODS

The present study was a secondary analysis of data collected for a cross-sectional study of residents in three assisted living facilities in North Carolina. The participants were aged 50 years or older, had normal to severely impaired cognition and spoke English. Upon obtaining informed consent, an oral assessment was completed by a trained geriatric dentist. A research team member who was blind to the oral examination outcomes then used the Minimum Data Set Cognition Scale to assess participants' cognition and the dental activities test to evaluate oral self-care and other DRFs. Descriptive statistics were used to describe the demographic, cognitive, functional and oral health status of the study participants. The impacts of cognitive and functional status on oral health measures were examined using simple linear regression models, negative binomial and zero-inflated negative binomial models.

RESULTS

A total of 91 long-term residents from three long-term care facilities participated in the study. Oral hygiene and gingival health were significantly associated with cognition (P = 0.056 and P = 0.017, respectively) and DRFs (P = 0.013 and P = 0.008, respectively). Residents with poor cognitive and dental-related function also presented with poor oral hygiene and gingival health.

CONCLUSION

The study results suggest that oral hygiene and gingival health were significantly associated with cognition and DRFs.

Association Between Functional Performance and Alzheimer's Disease Biomarkers in Individuals Without Dementia

OBJECTIVES

To examine the cross-sectional association between functional performance and Alzheimer's disease (AD) neuroimaging biomarkers in individuals without dementia (cognitively unimpaired (CU), and those with mild cognitive impairment (MCI)).

DESIGN

Cross-sectional.

SETTING

Olmsted County, Minnesota.

PARTICIPANTS

Population-based Mayo Clinic Study of Aging (MCSA) participants (aged ≥ 50, mean age 71.3 ± 10.2; 53.4% male; 28.3% apolipoprotein (APO)E ε4 allele carriers, 1,578 CU, 204 MCI) who underwent ¹¹ C-Pittsburgh compound B (¹¹ C-PiB) positron emission tomography (PET) (N=1,782).

MEASUREMENTS

We defined an abnormal (high) ¹¹ C-PiB-PET retention ratio as a standardized uptake value ratio greater than 1.42 (high amyloid; A+), abnormal (reduced) AD signature cortical thickness (neurodegeneration; N+) as less than 2.67 mm (MRI measurement), and biomarker groups according to the combination of abnormality (or not) for amyloid accumulation (A+/A-) and neurodegeneration (N+/N-). Functional performance was assessed using the Clinical Dementia Rating (CDR) Sum of Boxes (SOB) for functional domains and the Functional Activities Questionnaire (FAQ).

RESULTS

Participants with a CDR-SOB (functional) score greater than 0 were almost 4 times as likely to have N + (odds ratio (OR)=3.92, 95% confidence interval (CI)=1.77-8.67, adjusting for age, sex, education, global cognitive z-score, and APOE ε4 allele status; p<.001) and those with a FAQ score greater than 0 were 1.5 times as likely to have A + (OR=1.48, 95% CI=1.04-2.11, p=.03). Higher FAQ scores were associated with greater odds of A+N + and A-N + in CU participants.

CONCLUSION

The findings of this cross-sectional study supplement limited available information that supports an association between functional performance and AD neuroimaging biomarkers very early in the dementia pathophysiology. The associations should be validated in longitudinal studies. J Am Geriatr Soc 66:2274-2281, 2018.

Alzheimer's disease (AD) therapeutics - 2: Beyond amyloid - Re-defining AD and its causality to discover effective therapeutics

Compounds targeted for the treatment of Alzheimer's Disease (AD) have consistently failed in clinical trials despite evidence for target engagement and pharmacodynamic activity. This questions the relevance of compounds acting at current AD drug targets - the majority of which reflect the seminal amyloid and, to a far lesser extent, tau hypotheses - and limitations in understanding AD causality as distinct from general dementia. The preeminence of amyloid and tau led to many alternative approaches to AD therapeutics being ignored or underfunded to the extent that their causal versus contributory role in AD remains unknown. These include: neuronal network dysfunction; cerebrovascular disease; chronic, local or systemic inflammation involving the innate immune system; infectious agents including herpes virus and prion proteins; neurotoxic protein accumulation associated with sleep deprivation, circadian rhythm and glymphatic/meningeal lymphatic system and blood-brain-barrier dysfunction; metabolic related diseases including diabetes, obesity hypertension and hypocholesterolemia; mitochondrial dysfunction and environmental factors. As AD has become increasingly recognized as a multifactorial syndrome, a single treatment paradigm is unlikely to work in all patients. However, the biomarkers required to diagnose patients and parse them into mechanism/disease-based sub-groups remain rudimentary and unvalidated as do non-amyloid, non-tau translational animal models. The social and economic impact of AD is also discussed in the context of new FDA regulatory draft guidance and a proposed biomarker-based Framework (re)-defining AD and its stages as part of the larger landscape of treating dementia via the 2013 G8 initiative to identify a disease-modifying therapy for dementia/AD by 2025.

Negative allosteric modulation of alpha 5-containing GABAA receptors engenders antidepressant-like effects and selectively prevents age-associated hyperactivity in tau-depositing mice

RATIONALE

Associated with frank neuropathology, patients with Alzheimer's disease suffer from a host of neuropsychiatric symptoms that include depression, apathy, agitation, and aggression. Negative allosteric modulators (NAMs) of α5-containing GABA_A receptors have been suggested to be a novel target for antidepressant action. We hypothesized that pharmacological modulation of this target would engender increased motivation in stressful environments.

METHODS

We utilized electrophysiological recordings from Xenopus oocytes and behavioral measures in mice to address this hypothesis.

RESULTS

In the forced-swim assay in mice that detects antidepressant drugs, the α5β3γ2 GABA_Α receptor NAM, RY-080 produced a marked antidepressant phenotype. Another compound, PWZ-029, was characterized as an α5β3γ2 receptor NAM of lower intrinsic efficacy in electrophysiological studies in Xenopus oocytes. In contrast to RY-080, PWZ-029 was only moderately active in the forced-swim assay and the α5β3γ2 receptor antagonist, Xli-093, was not active at all. The effects of RY-080 were prevented by the non-selective benzodiazepine receptor antagonist flumazenil as well as by the selective ligands, PWZ-029 and Xli-093. These findings demonstrate that this effect of RY-080 is driven by negative allosteric modulation of α5βγ2 GABA_A receptors. RY-080 was not active in the tail-suspension test. We also demonstrated a reduction in the age-dependent hyperactivity exhibited by transgenic mice that accumulate pathological tau (rTg4510 mice) by RY-080. The decrease in hyperactivity by RY-080 was selective for the hyperactivity of the rTg4510 mice since the locomotion of control strains of mice were not significantly affected by RY-080.

CONCLUSIONS

α5βγ2 GABA_A receptor NAMs might function as a pharmacological treatment for mood, amotivational syndromes, and psychomotor agitation in patients with Alzheimer's and other neurodegenerative disorders.

On the path to 2025: understanding the Alzheimer's disease continuum

Basic research advances in recent years have furthered our understanding of the natural history of Alzheimer's disease (AD). It is now recognized that pathophysiological changes begin many years prior to clinical manifestations of disease and the spectrum of AD spans from clinically asymptomatic to severely impaired. Defining AD purely by its clinical presentation is thus artificial and efforts have been made to recognize the disease based on both clinical and biomarker findings. Advances with biomarkers have also prompted a shift in how the disease is considered as a clinico-pathophysiological entity, with an increasing appreciation that AD should not only be viewed with discrete and defined clinical stages, but as a multifaceted process moving along a seamless continuum. Acknowledging this concept is critical to understanding the development process for disease-modifying therapies, and for initiating effective diagnostic and disease management options. In this article, we discuss the concept of a disease continuum from pathophysiological, biomarker, and clinical perspectives, and highlight the importance of considering AD as a continuum rather than discrete stages. While the pathophysiology of AD has still not been elucidated completely, there is ample evidence to support researchers and clinicians embracing the view of a disease continuum in their study, diagnosis, and management of the disease.

Recent Advances in the Inhibition of p38 MAPK as a Potential Strategy for the Treatment of Alzheimer's Disease

P38 mitogen-activated protein kinase (MAPK) is a crucial target for chronic inflammatory diseases. Alzheimer’s disease (AD) is characterized by the presence of amyloid plaques and neurofibrillary tangles in the brain, as well as neurodegeneration, and there is no known cure. Recent studies on the underlying biology of AD in cellular and animal models have indicated that p38 MAPK is capable of orchestrating diverse events related to AD, such as tau phosphorylation, neurotoxicity, neuroinflammation and synaptic dysfunction. Thus, the inhibition of p38 MAPK is considered a promising strategy for the treatment of AD. In this review, we summarize recent advances in the targeting of p38 MAPK as a potential strategy for the treatment of AD and envision possibilities of p38 MAPK inhibitors as a fundamental therapeutics for AD.

Vitamin D deficiency impairs neurobehavioral development in male mice

Vitamin D deficiency is prevalent especially in pregnant women and children. Several studies found that vitamin D status was negatively correlated with risk of senile neurobehavioral abnormality. The aim of this study was to investigate the effects of vitamin D deficiency on neurobehavioral development in mice. In vitamin D deficiency group, dams and their male pups were fed with vitamin D deficient (VDD) diet, in which vitamin D was depleted. Anxiety-related behavior, depressive-like behavior, spatial learning and memory were measured. As expected, serum 25(OH)D level was reduced in VDD diet-fed mice. An anhedonia state, a key depressive-like behavior, was observed in VDD diet-fed mice. In open-field test, peripheral time was decreased and internal time was increased in VDD diet-fed mice. In elevated plus maze, the latency of the first entry into open arms was increased and the number of crossing in open arms was elevated in VDD diet-fed mice. Morris Water Maze showed that VDD-fed mice showed longer escape latency in the first six days. On the seventh day, escape latency was increased in VDD diet-fed mice. These results provide evidence that vitamin D deficiency impairs neurobehavioral development.

Comorbidity and progression of late onset Alzheimer's disease: A systematic review

Background

Alzheimer’s disease is a neurodegenerative syndrome characterized by multiple dimensions including cognitive decline, decreased daily functioning and psychiatric symptoms. This systematic review aims to investigate the relation between somatic comorbidity burden and progression in late-onset Alzheimer’s disease (LOAD).

Methods

We searched four databases for observational studies that examined cross-sectional or longitudinal associations of cognitive or functional or neuropsychiatric outcomes with comorbidity in individuals with LOAD. From the 7966 articles identified originally, 11 studies were included in this review. The Newcastle-Ottawa quality assessment was used. The large variation in progression measures, comorbidity indexes and study designs hampered the ability to perform a meta-analysis. This review was registered with PROSPERO under DIO: 10.15124/CRD42015027046.

Results

Nine studies indicated that comorbidity burden was associated with deterioration in at least one of the three dimensions of LOAD examined. Seven out of ten studies investigating cognition found comorbidities to be related to decreased cognitive performance. Five out of the seven studies investigating daily functioning showed an association between comorbidity burden and decreased daily functioning. Neuropsychiatric symptoms (NPS) increased with increasing comorbidity burden in two out of three studies investigating NPS. Associations were predominantly found in studies analyzing the association cross-sectionally, in a time-varying manner or across short follow-up (≤2 years). Rarely baseline comorbidity burden appeared to be associated with outcomes in studies analyzing progression over longer follow-up periods (>2 years).

Conclusion

This review provides evidence of an association between somatic comorbidities and multifaceted LOAD progression. Given that time-varying comorbidity burden, but much less so baseline comorbidity burden, was associated with the three dimensions prospectively, this relationship cannot be reduced to a simple cause-effect relation and is more likely to be dynamic. Therefore, both future studies and clinical practice may benefit from regarding comorbidity as a modifiable factor with a possibly fluctuating influence on LOAD.

Operationalizing the Diagnostic Criteria for Mild Cognitive Impairment: The Salience of Objective Measures in Predicting Incident Dementia

OBJECTIVE

Mild cognitive impairment (MCI) is considered an intermediate stage between normal aging and dementia. It is diagnosed in the presence of subjective cognitive decline and objective cognitive impairment without significant functional impairment, although there are no standard operationalizations for each of these criteria. The objective of this study is to determine which operationalization of the MCI criteria is most accurate at predicting dementia.

DESIGN

Six-year longitudinal study, part of the Sydney Memory and Ageing Study.

SETTING

Community-based.

PARTICIPANTS

873 community-dwelling dementia-free adults between 70 and 90 years of age. Persons from a non-English speaking background were excluded.

MEASUREMENTS

Seven different operationalizations for subjective cognitive decline and eight measures of objective cognitive impairment (resulting in 56 different MCI operational algorithms) were applied. The accuracy of each algorithm to predict progression to dementia over 6 years was examined for 618 individuals.

RESULTS

Baseline MCI prevalence varied between 0.4% and 30.2% and dementia conversion between 15.9% and 61.9% across different algorithms. The predictive accuracy for progression to dementia was poor. The highest accuracy was achieved based on objective cognitive impairment alone. Inclusion of subjective cognitive decline or mild functional impairment did not improve dementia prediction accuracy.

CONCLUSIONS

Not MCI, but objective cognitive impairment alone, is the best predictor for progression to dementia in a community sample. Nevertheless, clinical assessment procedures need to be refined to improve the identification of pre-dementia individuals.

Disease Progression in Mild Dementia due to Alzheimer Disease in an 18-Month Observational Study (GERAS): The Impact on Costs and Caregiver Outcomes

Background/Aims

We assessed whether cognitive and functional decline in community-dwelling patients with mild Alzheimer disease (AD) dementia were associated with increased societal costs and caregiver burden and time outcomes.

Methods

Cognitive decline was defined as a ≥3-point reduction in the Mini-Mental State Examination and functional decline as a decrease in the ability to perform one or more basic items of the Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory (ADCS-ADL) or ≥20% of instrumental ADL items. Total societal costs were estimated from resource use and caregiver hours using 2010 costs. Caregiver burden was assessed using the Zarit Burden Interview (ZBI); caregiver supervision and total hours were collected.

Results

Of 566 patients with mild AD enrolled in the GERAS study, 494 were suitable for the current analysis. Mean monthly total societal costs were greater for patients showing functional (+61%) or cognitive decline (+27%) compared with those without decline. In relation to a typical mean monthly cost of approximately EUR 1,400 at baseline, this translated into increases over 18 months to EUR 2,254 and 1,778 for patients with functional and cognitive decline, respectively. The number of patients requiring supervision doubled among patients showing functional or cognitive decline compared with those not showing decline, while caregiver total time increased by 70 and 33%, respectively and ZBI total score by 5.3 and 3.4 points, respectively.

Conclusion

Cognitive and, more notably, functional decline were associated with increases in costs and caregiver outcomes in patients with mild AD dementia.

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

INTRODUCTION

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

METHODS/DESIGN

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

DISCUSSION

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

Assessing quality of life in Alzheimer's disease: Implications for clinical trials

Introduction

Characterization of the quality of life (QOL) in Alzheimer's disease (AD) scale within the context of a clinical trial may inform its applicability in future trials.

Methods

Using data from 1322 patients enrolled in two phase-III studies (EXPEDITION 1 [NCT00905372] and 2 [NCT00904683]) of intravenous solanezumab in outpatients with mild AD dementia, correlations between patient- and caregiver-assessed QOL and between QOL and clinical outcome measures were examined. Longitudinal effects of solanezumab over 80 weeks were explored, controlling for patient and caregiver baseline characteristics.

Results

Caregivers rated patients' QOL worse than did patients themselves. Patients' QOL was correlated, albeit modestly, with clinical/health measures. Patients' QOL changed minimally over 80 weeks, although a treatment effect of solanezumab on QOL was detected.

Discussion

Further investigations are needed to determine the optimal measures with which to quantify and qualify QOL of patients with mild AD.

Integrins in synapse regulation

Integrins are a large family of extracellular matrix (ECM) receptors. In the developing and adult brain, many integrins are present at high levels at synapses. The tetrapartite structure of synapses - which comprises presynaptic and postsynaptic neurons, the ECM and glial processes - places synaptic integrins in an excellent position to sense dynamic changes in the synaptic environment and use this information to coordinate further changes in synapse structure and function that will shape neural circuit properties. Recent developments in our understanding of the cellular and physiological roles of integrins, which range from control of neural process outgrowth and synapse formation to regulation of synaptic plasticity and memory, enable us to attempt a synthesis of synaptic integrin function.

Modeling Alzheimer Disease Through Functional Independence and Participation

INTRODUCTION

The relationship between cognitive and functional impairment in Alzheimer Disease (AD) at the earliest stages of the disease is not well characterized. This study aimed at investigating such relationships along AD evolution by means of the Disability Assessment for Dementia (DAD).

METHODS

Consecutive pairs of AD outpatients and their primary informal caregivers were enrolled. Patients were evaluated by means of the Mini Mental State Examination and neuropsychological tests. A clinician completed the Clinical Dementia Rating Scale to stage dementia severity and interviewed the caregivers to complete the Neuropsychiatric Inventory to assess behavioral disturbances and the DAD to evaluate patients' functional competence.

RESULTS

A total of 158 dyads were enrolled; the Mini Mental State Examination score was used to stratify patients into 4 groups (>24; 20 to 23.9; 10 to 19.9; <10) that were compared. The statistical analysis revealed that all the cognitive domains were positively related to functional independence, but only logical and executive functions seemed to predict autonomy. An intergroup comparison did not show significant differences in the DAD subscales measuring initiation, planning and organization, and performance. The role of education emerged, confirming the relevance of cognitive reserve.

DISCUSSION

As the field moves toward earlier intervention in preclinical AD, the detection of early functional changes may drive the definition of trials on prevention or intervention for dementia.

Early detection of cryptic memory and glucose uptake deficits in pre-pathological APP mice

Earlier diagnosis and treatment of Alzheimer's disease would greatly benefit from the identification of biomarkers at the prodromal stage. Using a prominent animal model of aspects of the disease, we here show using clinically relevant methodologies that very young, pre-pathological PDAPP mice, which overexpress mutant human amyloid precursor protein in the brain, exhibit two cryptic deficits that are normally undetected using standard methods of assessment. Despite learning a spatial memory task normally and displaying normal brain glucose uptake, they display faster forgetting after a long delay following performance to a criterion, together with a strong impairment of brain glucose uptake at the time of attempted memory retrieval. Preliminary observations suggest that these deficits, likely caused by an impairment in systems consolidation, could be rescued by immunotherapy with an anti-β-amyloid antibody. Our data suggest a biomarker strategy for the early detection of β-amyloid-related abnormalities.

Identifying early signs of Alzheimer's disease is important when it comes to diagnosis and treatment. Here, the authors identify subtle memory retrieval deficits and associated brain glucose uptake impairments in very young mouse models of Alzheimer's, prior to plaque development.