Multidomain modifiable dementia risk factors are associated with poorer cognition in midlife

OBJECTIVE

Studies of modifiable dementia risk factors (MDRFs) generally consider MDRFs individually, despite strong evidence that they co-occur in adult populations. In a large sample of middle-aged adults, this study aimed to determine the frequency and co-occurrence of MDRFs, spanning five domains (mood symptomatology, risky lifestyle behaviors, cardiovascular conditions, cognitive/social engagement, sleep disorders/symptomatology). The relationship between number of domains in which MDRFs were reported with cognitive performance and subjective cognitive concerns was then determined.

METHOD

Middle-aged adults (n = 1,610) enrolled in the Healthy Brain Project and completed self-report surveys about their health and lifestyle. Participants also completed the Cogstate Brief Battery and the Cognitive Function Instrument, a measure of subjective ratings of cognition. Participants were classified according to number of domains (mood symptomatology, risky lifestyle behaviors, cardiovascular conditions, cognitive/social engagement, sleep disorders/symptomatology) in which they reported at least one MDRF (0-5). Age, sex, education, and ethnicity were adjusted for in analyses.

RESULTS

Most individuals (66.5%) reported MDRFs in two or more domains. Compared with individuals displaying no MDRFs, individuals with MDRFs in 3-5 domains showed worse learning/working memory performance and greater subjective cognitive concerns, with the magnitude of these differences moderate-to-large (d = 0.30-0.93). Individuals displaying MDRFs in five domains also showed worse attention/psychomotor function (d = 0.58) compared to those displaying no MDRFs.

CONCLUSIONS

These findings may suggest that multidomain MDRFs are highly frequent in middle-aged adults and are related to poorer cognition. This supports that modifiable dementia risk is multidimensional and raises the possibility that multidomain behavioral intervention trials in middle-aged adults may be useful to delay or prevent cognitive impairment or decline. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Identifying subtle functional change in individuals with mild cognitive impairment: development and validation of the Healthy Brain Ageing - Functional Assessment Questionnaire

Accumulating research suggests that individuals with Mild Cognitive Impairment (MCI) experience subtle functional changes, but that available functional assessment tools are insensitive to this. To address this gap, we describe the development and validation of the self-report, "Healthy Brain Ageing Functional Assessment Questionnaire" (HBA-FAQ). We examined the factor structure and psychometric properties of the HBA-FAQ in 503 participants with normal cognition, subjective cognitive decline (SCD), MCI or dementia. Our results found the HBA-FAQ to have good reliability, validity and stronger discriminative ability between healthy control participants and those with SCD (0.734, p = .001), MCI (0.666, p = .012) and dementia (0.798, p < .001) compared to a widely-used instrumental activities of daily living screener. In conclusion, the HBA-FAQ is a valid, reliable self-report tool, providing an efficient and sensitive approach to identifying subtle changes in daily functioning in older people at risk of dementia.

Ventricular Electrocardiographic Signatures Associated with Dementia and Plasma Alzheimer's Disease Biomarkers in Older Adults: A Population-Based Study

BACKGROUND

Evidence has emerged that altered ventricular electrocardiogram profiles are associated with dementia, but the neuropathological mechanisms underlying their associations are poorly understood.

OBJECTIVE

To investigate the interrelationships of ventricular electrocardiogram profiles with dementia and plasma Alzheimer's disease (AD) biomarkers among older adults.

METHODS

This population-based cross-sectional study included 5,153 participants (age ≥65 years; 57.3% women) living in rural communities in China; of these, 1,281 had data on plasma amyloid-β (Aβ)40, Aβ42, total-tau, and neurofilament light chain (NfL) protein. The QT, QTc, JT, JTc, QRS intervals, and QRS axis were derived from the 10-second electrocardiogram recording. The DSM-IV criteria were followed for clinical diagnosis of dementia, the NIA-AA criteria for AD, and the NINDS-AIREN criteria for vascular dementia (VaD). Data were analyzed using general linear models, multinomial logistic models, and restricted cubic splines.

RESULTS

Of the 5,153 participants, 299 (5.8%) were diagnosed with dementia, including 194 with AD and 94 with VaD. Prolonged QT, QTc, JT, and JTc intervals were significantly associated with all-cause dementia, AD, and VaD (p < 0.05). Left QRS axis deviation was significantly associated with all-cause dementia and VaD (p < 0.01). In the subsample of plasma biomarkers (n = 1,281), prolonged QT, JT, and JTc intervals were significantly associated with a lower Aβ42/Aβ40 ratio and higher plasma NfL concentrations (p < 0.05).

CONCLUSION

Alterations in ventricular repolarization and depolarization are independently associated with all-cause dementia, AD, VaD, and AD plasma biomarkers in older adults (age ≥65 years). Ventricular electrocardiogram parameters may be valuable clinical markers for dementia and the underlying AD pathologies and neurodegeneration.

Association of Echocardiographic Measures of Left Atrial Function and Size With Incident Dementia

IMPORTANCE

Atrial myopathy-characterized by alterations in left atrial (LA) function and size-is associated with ischemic stroke, independent of atrial fibrillation (AF). Electrocardiographic markers of atrial myopathy are associated with dementia, but it is unclear whether 2-dimensional echocardiographic (2DE)-defined LA function and size are associated with dementia.

OBJECTIVE

To examine the association of LA function and size with incident dementia.

DESIGN, SETTING, AND PARTICIPANTS

The Atherosclerosis Risk in Communities (ARIC) study is a community-based prospective cohort. An exploratory, retrospective analysis was conducted. ARIC centers are located in Forsyth County, North Carolina; Jackson, Mississippi; Washington County, Maryland; and suburban Minneapolis, Minnesota. For this analysis, visit 5 (2011-2013) served as the baseline. Participants without prevalent AF and stroke and who had 2DEs in 2011-2013 were included and surveilled through December 31, 2019.

EXPOSURES

LA function (reservoir strain, conduit strain, contractile strain, emptying fraction, passive emptying fraction, and active emptying fraction), and LA size (maximal and minimal volume index) as evaluated by 2DE.

MAIN OUTCOMES AND MEASURES

Dementia cases were identified using in-person and phone cognitive assessments, hospitalization codes, and death certificates. Cox proportional hazards models were used.

RESULTS

Among 4096 participants (mean [SD] age, 75 [5] years; 60% women; 22% Black individuals), 531 dementia cases were ascertained over a median follow-up of 6 years. Dementia incidence for the lowest LA quintile was 4.80 for reservoir strain, 3.94 for conduit strain, 3.29 for contractile strain, 4.20 for emptying fraction, 3.67 for passive emptying fraction, and 3.27 for active emptying fraction per 100 person-years. After full-model adjustments, there were statistically significant associations between measures of LA function and dementia; the hazard ratios (HRs) from the lowest vs highest quintile for reservoir strain were 1.98 (95% CI, 1.42-2.75); for conduit strain, 1.50 (95% CI, 1.09-2.06); for contractile strain, 1.57 (95% CI, 1.16-2.14); for emptying fraction, 1.87 (95% CI, 1.31-2.65); and for active emptying fraction, 1.43 (95% CI, 1.04-1.96). LA passive emptying fraction was not significantly associated with dementia (HR, 1.26 [95% CI, 0.93-1.71]). Dementia incidence for the highest LA maximal volume index quintile was 3.18 per 100 person-years (HR for highest vs lowest quintile, 0.77 [95% CI, 0.58-1.02]) and for the highest minimal volume index quintile was 3.50 per 100 person-years (HR for the highest vs lowest quintile, 0.95 [95% CI, 0.71-1.28]). Both measures were not significantly associated with dementia. These findings were robust to sensitivity analyses that excluded participants with incident AF or stroke.

CONCLUSIONS AND RELEVANCE

In this exploratory analysis of a US community-based cohort, several echocardiographic measures of lower LA function were significantly associated with an increased risk of subsequent dementia. Measures of LA size were not significantly associated with dementia risk. These findings suggest that impaired LA function may be a risk factor associated with dementia.

Atrial Fibrillation and Dementia: A Report From the AF-SCREEN International Collaboration

Growing evidence suggests a consistent association between atrial fibrillation (AF) and cognitive impairment and dementia that is independent of clinical stroke. This report from the AF-SCREEN International Collaboration summarizes the evidence linking AF to cognitive impairment and dementia. It provides guidance on the investigation and management of dementia in patients with AF on the basis of best available evidence. The document also addresses suspected pathophysiologic mechanisms and identifies knowledge gaps for future research. Whereas AF and dementia share numerous risk factors, the association appears to be independent of these variables. Nevertheless, the evidence remains inconclusive regarding a direct causal effect. Several pathophysiologic mechanisms have been proposed, some of which are potentially amenable to early intervention, including cerebral microinfarction, AF-related cerebral hypoperfusion, inflammation, microhemorrhage, brain atrophy, and systemic atherosclerotic vascular disease. The mitigating role of oral anticoagulation in specific subgroups (eg, low stroke risk, short duration or silent AF, after successful AF ablation, or atrial cardiopathy) and the effect of rhythm versus rate control strategies remain unknown. Likewise, screening for AF (in cognitively normal or cognitively impaired patients) and screening for cognitive impairment in patients with AF are debated. The pathophysiology of dementia and therapeutic strategies to reduce cognitive impairment warrant further investigation in individuals with AF. Cognition should be evaluated in future AF studies and integrated with patient-specific outcome priorities and patient preferences. Further large-scale prospective studies and randomized trials are needed to establish whether AF is a risk factor for cognitive impairment, to investigate strategies to prevent dementia, and to determine whether screening for unknown AF followed by targeted therapy might prevent or reduce cognitive impairment and dementia.

Anticoagulant prescribing for atrial fibrillation and risk of incident dementia

OBJECTIVE

The aim of this study was to investigate the association between oral anticoagulant type (direct oral anticoagulants (DOACs) vs vitamin K antagonists (VKAs)) and incident dementia or mild cognitive impairment (MCI) among patients with newly diagnosed atrial fibrillation (AF).

METHODS

Using linked electronic health record (EHR) data from the Clinical Practice Research Datalink in the UK, we conducted a historical cohort study among first-time oral anticoagulant users with incident non-valvular AF diagnosed from 2012 to 2018. We compared the incidence of (1) clinically coded dementia and (2) MCI between patients prescribed VKAs and DOACs using Cox proportional hazards regression models, with age as the underlying timescale, accounting for calendar time and time on treatment, sociodemographic and lifestyle factors, clinical comorbidities and medications.

RESULTS

Of 39 200 first-time oral anticoagulant users (44.6% female, median age 76 years, IQR 68-83), 20 687 (53%) were prescribed a VKA and 18 513 (47%) a DOAC at baseline. Overall, 1258 patients (3.2%) had GP-recorded incident dementia, incidence rate 16.5 per 1000 person-years. DOAC treatment for AF was associated with a 16% reduction in dementia diagnosis compared with VKA treatment in the whole cohort (adjusted HR 0.84, 95% CI: 0.73 to 0.98) and with a 26% reduction in incident MCI (adjusted HR 0.74, 95% CI: 0.65 to 0.84). Findings were similar across various sensitivity analyses.

CONCLUSIONS

Incident EHR-recorded dementia and MCI were less common among patients prescribed DOACs for new AF compared with those prescribed VKAs.

Diagnostic contribution and therapeutic perspectives of transcranial magnetic stimulation in dementia

Transcranial magnetic stimulation (TMS) is a powerful tool to probe in vivo brain circuits, as it allows to assess several cortical properties such asexcitability, plasticity and connectivity in humans. In the last 20 years, TMS has been applied to patients with dementia, enabling the identification of potential markers of thepathophysiology and predictors of cognitive decline; moreover, applied repetitively, TMS holds promise as a potential therapeutic intervention. The objective of this paper is to present a comprehensive review of studies that have employed TMS in dementia and to discuss potential clinical applications, from the diagnosis to the treatment. To provide a technical and theoretical framework, we first present an overview of the basic physiological mechanisms of the application of TMS to assess cortical excitability, excitation and inhibition balance, mechanisms of plasticity and cortico-cortical connectivity in the human brain. We then review the insights gained by TMS techniques into the pathophysiology and predictors of progression and response to treatment in dementias, including Alzheimer's disease (AD)-related dementias and secondary dementias. We show that while a single TMS measure offers low specificity, the use of a panel of measures and/or neurophysiological index can support the clinical diagnosis and predict progression. In the last part of the article, we discuss the therapeutic uses of TMS. So far, only repetitive TMS (rTMS) over the left dorsolateral prefrontal cortex and multisite rTMS associated with cognitive training have been shown to be, respectively, possibly (Level C of evidence) and probably (Level B of evidence) effective to improve cognition, apathy, memory, and language in AD patients, especially at a mild/early stage of the disease. The clinical use of this type of treatment warrants the combination of brain imaging techniques and/or electrophysiological tools to elucidate neurobiological effects of neurostimulation and to optimally tailor rTMS treatment protocols in individual patients or specific patient subgroups with dementia or mild cognitive impairment.

Gender-specific design and effectiveness of non-pharmacological interventions against cognitive decline and dementia-protocol for a systematic review and meta-analysis

Introduction

Dementia is a public health priority with projected increases in the number of people living with dementia worldwide. Prevention constitutes a promising strategy to counter the dementia epidemic, and an increasing number of lifestyle interventions has been launched aiming at reducing risk of cognitive decline and dementia. Gender differences regarding various modifiable risk factors for dementia have been reported, however, evidence on gender-specific design and effectiveness of lifestyle trials is lacking. Therefore, we aim to systematically review evidence on gender-specific design and effectiveness of trials targeting cognitive decline and dementia.

Methods and analysis

We will conduct a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Databases MEDLINE (PubMed interface), PsycINFO, Web of Science Core Collection, Cochrane Central Register of Controlled Trials (CENTRAL) and ALOIS will be searched for eligible studies using a predefined strategy, complemented by searches in clinical trials registers and Google for grey literature. Studies assessing cognitive function (overall measure or specific subdomains) as outcome in dementia-free adults will be included, with analyses stratified by level of cognitive functioning at baseline: a) cognitively healthy b) subjective cognitive decline 3) mild cognitive impairment. Two reviewers will independently evaluate eligible studies, extract data and determine methodological quality using the Scottish Intercollegiate Guidelines Network (SIGN)-criteria. If sufficient data with regards to quality and quantity are available, a meta-analysis will be conducted.

Ethics and dissemination

No ethical approval will be required as no primary data will be collected.

PROSPERO registration number

CRD42021235281.

Effectiveness and safety of acupuncture in treating sleep disturbance in dementia patients: A PRISMA-compliant systematic review and limitations of current evidence

BACKGROUND

Dementia is of increasing importance, as it is a major public health problem worldwide. Sleep disturbance is common in dementia patients and may be associated with worse cognitive symptoms or behavioral and psychological symptoms of dementia. Non-pharmacological approaches, such as acupuncture, for treating this clinical condition are gaining importance. This study aimed to comprehensively search and analyze randomized controlled clinical trials (RCTs) of acupuncture in treating sleep disturbance or sleep disorders in dementia patients.

METHODS

A comprehensive search was conducted from 12 electronic databases on December 2, 2020. We included RCTs reporting the effectiveness and safety of acupuncture in treating sleep disorders or disturbance in dementia patients. The methodological quality of the included studies was assessed using the Cochrane Collaboration's risk-of-bias tool.

RESULTS

Five articles with four original RCTs met the inclusion criteria. These studies reported clinical data suggesting that adjuvant acupuncture for hypnotics, and ear acupressure in dementia patients with sleep disorders or sleep disturbance may have clinical benefits in certain sleep-related parameters and total effective rate (TER). Only 1 study reported the safety profile of the intervention, and no acupuncture-related adverse reactions were reported. Some studies compared 2 kinds of acupuncture methods, and found that specific acupuncture methods were superior to conventional acupuncture in improving sleep-related parameters, cognitive function and TER. The methodological quality of the included clinical studies was not high.

CONCLUSIONS

There were limited acupuncture studies on this topic. Given the number of studies included and their sample size, methodological quality, and heterogeneities, clinically relevant conclusions could not be drawn. Further clinical studies are needed in this field considering its urgency and importance.

Effectiveness of mindfulness-based interventions for people with dementia and mild cognitive impairment: A meta-analysis and implications for future research

Objective

To assess the effectiveness of mindfulness-based interventions on people with dementia and mild cognitive impairment.

Methods

We searched several electronic databases, namely Cochrane Library, EMBASE, and MEDLINE with no limitations for language or document type (last search: 1 February 2020). Randomized controlled trials of mindfulness-based interventions for people with dementia and mild cognitive impairment compared to active-control interventions, waiting lists, or treatment as usual were included. Predefined outcomes were anxiety symptoms, depressive symptoms, cognitive function, quality of life, mindfulness, ADL and attrition. We used the random effects model (DerSimonian-Laird method) for meta-analysis, reporting effect sizes as Standardized Mean Difference. Heterogeneity was assessed with the I² statistics.

Results

Eight randomized controlled trials, involving 276 patients, met the eligibility criteria and were included in the meta-analysis. We found no significant effects for mindfulness-based interventions in either the short-term or the medium- to long-term on any outcomes, when compared with control conditions. The number of included studies and sample sizes were too small. Additionally, the quality of evidence was low for each randomized controlled trial included in the analysis. This is primarily due to lack of intent-to-treat analysis, high risk of bias, and imprecise study results. The limited statistical power and weak body of evidence prevented us from reaching firm conclusions.

Conclusions

We found no significant effects of mindfulness-based interventions on any of the outcomes when compared with control conditions. The evidence concerning the efficacy of mindfulness-based interventions in this population is scarce in terms of both quality and quantity. More well-designed, rigorous, and large-scale randomized controlled trials are needed.

Genetically engineered MAPT 10+16 mutation causes pathophysiological excitability of human iPSC-derived neurons related to 4R tau-induced dementia

Human iPSC lines represent a powerful translational model of tauopathies. We have recently described a pathophysiological phenotype of neuronal excitability of human cells derived from the patients with familial frontotemporal dementia and parkinsonism (FTDP-17) caused by the MAPT 10+16 splice-site mutation. This mutation leads to the increased splicing of 4R tau isoforms. However, the role of different isoforms of tau protein in initiating neuronal dementia-related dysfunction, and the causality between the MAPT 10+16 mutation and altered neuronal activity have remained unclear. Here, we employed genetically engineered cells, in which the IVS10+16 mutation was introduced into healthy donor iPSCs to increase the expression of 4R tau isoform in exon 10, aiming to explore key physiological traits of iPSC-derived MAPT IVS10+16 neurons using patch-clamp electrophysiology and multiphoton fluorescent imaging techniques. We found that during late in vitro neurogenesis (from ~180 to 230 days) iPSC-derived cortical neurons of the control group (parental wild-type tau) exhibited membrane properties compatible with "mature" neurons. In contrast, MAPT IVS10+16 neurons displayed impaired excitability, as reflected by a depolarized resting membrane potential, an increased input resistance, and reduced voltage-gated Na+- and K+-channel-mediated currents. The mutation changed the channel properties of fast-inactivating Nav and decreased the Nav1.6 protein level. MAPT IVS10+16 neurons exhibited reduced firing accompanied by a changed action potential waveform and severely disturbed intracellular Ca2+ dynamics, both in the soma and dendrites, upon neuronal depolarization. These results unveil a causal link between the MAPT 10+16 mutation, hence overproduction of 4R tau, and a dysfunction of human cells, identifying a biophysical basis of changed neuronal activity in 4R tau-triggered dementia. Our study lends further support to using iPSC lines as a suitable platform for modelling tau-induced human neuropathology in vitro.

Nutritional status, dementia, and mobility among nursing home's residents: First exhaustive cross-sectional study in Limousin territory (France)

BACKGROUND

Aging is accompanied by a drop in the level of health and autonomy, within Western countries more and more people being cared for in nursing homes (NH). The nutritional data in NH in France remain poor, not exhaustive and not representative. The objective of the study was to assess the nutritional status, dementia and mobility patterns among residents of NH in the Limousin territory of France.

METHODS

The study was cross-sectional, descriptive and exhaustive, conducted with the residents of 13 voluntary NH. Undernutrition was identified using French High Authority for Health criteria, and obesity if Body Mass Index >30, in the absence undernutrition criterion. The Mini Mental State examination scores was used for dementia assessment at the threshold of 24. The Mini Nutritional AssessmentTM was used for mobilitity assessment. The statistics were significant at the 5% threshold.

RESULTS

866 residents (70.6% women) included with an average age of 85.3 ± 9.3 years. Undernutrition was 27.5%, obesity 22.9%, dementia 45.7% and very low mobility 68.9%. Women were older than men, more often undernourished, more often demented and more often had very low mobility (p<0.01). Undernutrition (p<0.0001) and low mobility (p<0.0001) were significantly higher among those with dementia versus those without dementia. Very low mobility was higher among undernourished (p<0.05).

CONCLUSIONS

Undernutrition and obesity are important problems in NH in France. Being a woman, having dementia and having a very low mobility may induce undernutrition.

Effectiveness and safety of traditional Chinese medicine in the treatment of senile hypotension: A protocol for systematic review and meta-analysis

BACKGROUND

Senile hypotension refers to those whose blood pressure (BP) is lower than 90/60 mm Hg. The consequences can not only cause insufficient cardio-cerebral perfusion, but severe cases may also cause angina pectoris and stroke. At present, Western medicine has no ideal therapeutic drugs for senile hypotension. The aim of this systematic review is to assess the effectiveness and safety of traditional Chinese medicine (TCM) therapy for senile hypotension.

METHODS

Two reviewers will electronically search the following databases: the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; China National Knowledge Infrastructure; Chinese Biomedical Literature Database; Chinese Scientific Journal Database (VIP database); and Wan-Fang Database from the inception, without restriction of publication status and languages. Additional searching including researches in progress, the reference lists and the citation lists of identified publications. Study selection, data extraction, and assessment of study quality will be performed independently by 2 reviewers. If it is appropriate for a meta-analysis, RevMan 5.4 statistical software will be used; otherwise, a descriptive analysis will be conducted. Data will be synthesized by either the fixed-effects or random-effects model according to a heterogeneity test. The results will be presented as risk ratio (RR) with 95% confidence intervals (CIs) for dichotomous data and weight mean difference (WMD) or standard mean difference 95% CIs for continuous data.

RESULTS

This study will provide a comprehensive review of the available evidence for the treatment of TCM with senile hypotension.

CONCLUSIONS

The conclusions of our study will provide an evidence to judge whether TCM is an effective and safe intervention for patients with senile hypotension.

ETHICS AND DISSEMINATION

This systematic review will be disseminated in a peer-reviewed journal or presented at relevant conferences. It is not necessary for a formal ethical approval because the data are not individualized.

TRIAL REGISTRATION NUMBER

INPLASY2020110091.

Association of sleep duration in middle and old age with incidence of dementia

Sleep dysregulation is a feature of dementia but it remains unclear whether sleep duration prior to old age is associated with dementia incidence. Using data from 7959 participants of the Whitehall II study, we examined the association between sleep duration and incidence of dementia (521 diagnosed cases) using a 25-year follow-up. Here we report higher dementia risk associated with a sleep duration of six hours or less at age 50 and 60, compared with a normal (7 h) sleep duration, although this was imprecisely estimated for sleep duration at age 70 (hazard ratios (HR) 1.22 (95% confidence interval 1.01-1.48), 1.37 (1.10-1.72), and 1.24 (0.98-1.57), respectively). Persistent short sleep duration at age 50, 60, and 70 compared to persistent normal sleep duration was also associated with a 30% increased dementia risk independently of sociodemographic, behavioural, cardiometabolic, and mental health factors. These findings suggest that short sleep duration in midlife is associated with an increased risk of late-onset dementia.

Sequence of clinical and neurodegeneration events in Parkinson's disease progression

Dementia is one of the most debilitating aspects of Parkinson's disease. There are no validated biomarkers that can track Parkinson's disease progression, nor accurately identify patients who will develop dementia and when. Understanding the sequence of observable changes in Parkinson's disease in people at elevated risk for developing dementia could provide an integrated biomarker for identifying and managing individuals who will develop Parkinson's dementia. We aimed to estimate the sequence of clinical and neurodegeneration events, and variability in this sequence, using data-driven statistical modelling in two separate Parkinson's cohorts, focusing on patients at elevated risk for dementia due to their age at symptom onset. We updated a novel version of an event-based model that has only recently been extended to cope naturally with clinical data, enabling its application in Parkinson's disease for the first time. The observational cohorts included healthy control subjects and patients with Parkinson's disease, of whom those diagnosed at age 65 or older were classified as having high risk of dementia. The model estimates that Parkinson's progression in patients at elevated risk for dementia starts with classic prodromal features of Parkinson's disease (olfaction, sleep), followed by early deficits in visual cognition and increased brain iron content, followed later by a less certain ordering of neurodegeneration in the substantia nigra and cortex, neuropsychological cognitive deficits, retinal thinning in dopamine layers, and further deficits in visual cognition. Importantly, we also characterize variation in the sequence. We found consistent, cross-validated results within cohorts, and agreement between cohorts on the subset of features available in both cohorts. Our sequencing results add powerful support to the increasing body of evidence suggesting that visual processing specifically is affected early in patients with Parkinson's disease at elevated risk of dementia. This opens a route to earlier and more precise detection, as well as a more detailed understanding of the pathological mechanisms underpinning Parkinson's dementia.

Olfactory dysfunction predicts the development of dementia in older patients with type 2 diabetes

AIMS

Olfactory dysfunction is associated with the transition from normal cognition to dementia in persons without type 2 diabetes. This study aimed to investigate whether olfactory dysfunction could be an early marker of future dementia in older patients with type 2 diabetes.

METHODS

This exploratory study included 151 older Japanese outpatients with type 2 diabetes who did not have a diagnosis of probable dementia at baseline. A multivariate logistic regression model was used to determine whether Open Essence (OE) test score at baseline is associated with the development of probable dementia.

RESULTS

Over 3 years, approximately 9% of the study subjects developed probable dementia. Subjects with olfactory dysfunction at baseline developed probable dementia more frequently than those without. Multivariate logistic regression showed that lower OE test score, higher age, lower Mini-Mental State Examination (MMSE) score, higher total protein concentration, and more frequent use of a sulfonylurea are significantly associated with the development of probable dementia. Stepwise multivariate regression analysis demonstrated that change in OE test score over 3 years is significantly associated with change in MMSE score.

CONCLUSIONS

Our study suggested that olfactory dysfunction precedes the development of probable dementia in older patients with type 2 diabetes.

Hearing and dementia: from ears to brain

The association between hearing impairment and dementia has emerged as a major public health challenge, with significant opportunities for earlier diagnosis, treatment and prevention. However, the nature of this association has not been defined. We hear with our brains, particularly within the complex soundscapes of everyday life: neurodegenerative pathologies target the auditory brain, and are therefore predicted to damage hearing function early and profoundly. Here we present evidence for this proposition, based on structural and functional features of auditory brain organization that confer vulnerability to neurodegeneration, the extensive, reciprocal interplay between 'peripheral' and 'central' hearing dysfunction, and recently characterized auditory signatures of canonical neurodegenerative dementias (Alzheimer's disease, Lewy body disease and frontotemporal dementia). Moving beyond any simple dichotomy of ear and brain, we argue for a reappraisal of the role of auditory cognitive dysfunction and the critical coupling of brain to peripheral organs of hearing in the dementias. We call for a clinical assessment of real-world hearing in these diseases that moves beyond pure tone perception to the development of novel auditory 'cognitive stress tests' and proximity markers for the early diagnosis of dementia and management strategies that harness retained auditory plasticity.

Clinical Relevance of [18F]Florbetaben and [18F]FDG PET/CT Imaging on the Management of Patients with Dementia

PET of β-Amyloid plaques (Aβ) using [¹⁸F]florbetaben ([¹⁸F]FBB) and [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) increasingly aid clinicians in early diagnosis of dementia, including Alzheimer’s disease (AD), frontotemporal disease, dementia with Lewy bodies, and vascular dementia. The aim of this retrospective analysis was to evaluate clinical relevance of [¹⁸F]FBB, [¹⁸F]FDG PET and complimentary CSF measurements in patients with suspected dementia. In this study, 40 patients with clinically suspected or history of dementia underwent (1) measurement of Aβ peptides, total tau, and p-tau protein levels in the cerebrospinal fluid (CSF) compared with healthy controls (HC); (2) clinical and neuropsychological assessment, which included Consortium to Establish a Registry for Alzheimer’s Disease neuropsychological assessment battery (CERAD-NAB); (3) [¹⁸F]FBB and [¹⁸F]FDG PET imaging within an average of 3 weeks. The subjects were within 15 days stratified using PET, CSF measurements as HC, mild cognitive impaired (MCI) and dementia including Alzheimer´s disease. The predictive dementia-related cognitive decline values were supporting the measurements. PET images were evaluated visually and quantitatively using standard uptake value ratios (SUVR). Twenty-one (52.5%) subjects were amyloid-positive (Aβ+), with a median neocortical SUVR of 1.80 for AD versus 1.20 relative to the respective 19 (47.5 %) amyloid-negative (Aβ-) subjects. Moreover, the [¹⁸F]FDG and [¹⁸F]FBB confirmed within a sub-group of 10 patients a good complimentary role by correlation between amyloid pathology and brain glucose metabolism in 8 out of 10 subjects. The results suggest the clinical relevance for [¹⁸F]FBB combined with [¹⁸F]FDG PET retention and CFS measurements serving the management of our patients with dementia. Therefore, [¹⁸F]FBB combined with [¹⁸F]FDG PET is a helpful tool for differential diagnosis, and supports the patients’ management as well as treatment.

[Effect of physical exercise and diet based interventions on the evolution of cognitive impairment to dementia in subjects older than 45 years. A systematic review.]

BACKGROUND

Dementia is a global public health problem. Drugs for this indication have shown limited benefit. The aim of the present study is to synthesize and analyze the available scientific evidence about effectiveness of interventions on diet and / or physical exercise by considering cognitive function as an outcome measure, in people over 45 years of age with mild cognitive impairment (MCI) in their evolution to Alzheimer's disease.

METHODS

A bibliographic search of randomized clinical trials, systematic reviews, and meta-analyzes published from May 2008 to May 2019 was carried out in the Medline and The Cochrane Library databases. A total of 169 publications were identified, of which 42 studies that fulfilled inclusion criteria were reviewed.

RESULTS

It was found that scheduled physical exercise of moderate-high intensity, performed 3 to 5 days a week, following a dietary pattern such as Mediterranean diet or DASH diet improve overall cognitive function in subjects with MCI. The results are enhanced when the studies combine both interventions and include cognitive stimulation exercises, allowing increasing the functionality of the subjects.

CONCLUSIONS

Intervention on modifiable factors such as physical exercise and diet provides cognitive protection in subjects with MCI, improving their quality of life, functionality and independence. The heterogeneity of the studies makes it difficult to draw up more concrete recommendations.

Alzheimer's Disease Projection From Normal to Mild Dementia Reflected in Functional Network Connectivity: A Longitudinal Study

Background

Alzheimer's disease (AD) is the most common age-related problem and progresses in different stages, including mild cognitive impairment (early stage), mild dementia (middle-stage), and severe dementia (late-stage). Recent studies showed changes in functional network connectivity obtained from resting-state functional magnetic resonance imaging (rs-fMRI) during the transition from healthy aging to AD. By assuming that the brain interaction is static during the scanning time, most prior studies are focused on static functional or functional network connectivity (sFNC). Dynamic functional network connectivity (dFNC) explores temporal patterns of functional connectivity and provides additional information to its static counterpart.

Method

We used longitudinal rs-fMRI from 1385 scans (from 910 subjects) at different stages of AD (from normal to very mild AD or vmAD). We used group-independent component analysis (group-ICA) and extracted 53 maximally independent components (ICs) for the whole brain. Next, we used a sliding-window approach to estimate dFNC from the extracted 53 ICs, then group them into 3 different brain states using a clustering method. Then, we estimated a hidden Markov model (HMM) and the occupancy rate (OCR) for each subject. Finally, we investigated the link between the clinical rate of each subject with state-specific FNC, OCR, and HMM.

Results

All states showed significant disruption during progression normal brain to vmAD one. Specifically, we found that subcortical network, auditory network, visual network, sensorimotor network, and cerebellar network connectivity decrease in vmAD compared with those of a healthy brain. We also found reorganized patterns (i.e., both increases and decreases) in the cognitive control network and default mode network connectivity by progression from normal to mild dementia. Similarly, we found a reorganized pattern of between-network connectivity when the brain transits from normal to mild dementia. However, the connectivity between visual and sensorimotor network connectivity decreases in vmAD compared with that of a healthy brain. Finally, we found a normal brain spends more time in a state with higher connectivity between visual and sensorimotor networks.

Conclusion

Our results showed the temporal and spatial pattern of whole-brain FNC differentiates AD form healthy control and suggested substantial disruptions across multiple dynamic states. In more detail, our results suggested that the sensory network is affected more than other brain network, and default mode network is one of the last brain networks get affected by AD In addition, abnormal patterns of whole-brain dFNC were identified in the early stage of AD, and some abnormalities were correlated with the clinical score.

The behavioural phenotype of 14-month-old female TAU58/2 transgenic mice

Frontotemporal dementia (FTD) and Alzheimer's disease (AD) exhibit intracellular inclusions [neurofibrillary tangles (NFT's)] of microtubule-associated protein tau that contributes to neuronal dysfunction and death. Mutations in the microtubule-associated protein tau (MAPT) gene leads to tau hyperphosphorylation and promotes NFT formation. The TAU58/2 transgenic mouse model expresses mutant human tau (P301S mutation) and exhibits behavioural abnormalities relevant to dementia in early adulthood. Here we comprehensively determined the behavioural phenotype of TAU58/2 transgenic female mice at 14 months of age using test paradigms relevant to FTD and AD. TAU58/2 females showed a significant motor deficit and lower bodyweight compared to WT littermates. Transgenic females failed to habituate to the test arena in the light-dark test. Interestingly, transgenics did not exhibit an anxiolytic-like phenotype and intermediate-term spatial learning in the cheeseboard test was intact. However, a significant learning deficit was detected in the 1st trial across test days indicating impaired long-term spatial memory. In addition, the preference for a previously rewarded location was absent in transgenic females during probe trial testing. Finally, TAU58/2 mice had a defective acoustic startle response and impaired sensorimotor gating. In conclusion TAU58/2 mice exhibit several behavioural deficits that resemble those observed in human FTD and AD. Additionally, we observed a novel startle response deficit in these mice. At 14 months of age, TAU58/2 females represent a later disease stage and are therefore a potentially useful model to test efficacy of therapeutics to reverse or ameliorate behavioural deficits in post-onset tauopapthy-related neurodegenerative disorders.

How Does Dementia Begin to Manifest in Bipolar Disorder? A Description of Prodromal Clinical and Cognitive Changes

BACKGROUND

Older adults with bipolar disorder (BD) have increased dementia risk, but signs of dementia are difficult to detect in the context of pre-existing deficits inherent to BD.

OBJECTIVE

To identify the emergence of indicators of early dementia in BD.

METHODS

One hundred and fifty-nine non-demented adults with BD from the National Alzheimer's Coordinating Center (NACC) data repository underwent annual neuropsychological assessment up to 14 years (54.0 months average follow-up). Cognitive performance was examined longitudinally with linear mixed-effects models, and yearly differences between incident dementia cases and controls were examined in the six years prior to diagnosis.

RESULTS

Forty participants (25.2%) developed dementia over the follow-up period ('incident dementia cases'). Alzheimer's disease was the most common presumed etiology, though this was likely a result of sampling biases within NACC. Incident dementia cases showed declining trajectories in memory, language, and speeded attention two years prior to dementia onset.

CONCLUSION

In a sample of BD patients enriched for Alzheimer's type dementia, prodromal dementia in BD can be detected up to two years before onset using the same cognitive tests used in psychiatrically-healthy older adults (i.e., measures of verbal recall and fluency). Cognition in the natural course of BD is generally stable, and impairment or marked decline on measures of verbal episodic memory or semantic retrieval may indicate an early neurodegenerative process.

Blinded Clinical Evaluation for Dementia of Alzheimer's Type Classification Using FDG-PET: A Comparison Between Feature-Engineered and Non-Feature-Engineered Machine Learning Methods

BACKGROUND

Advanced machine learning methods can aid in the identification of dementia risk using neuroimaging-derived features including FDG-PET. However, to enable the translation of these methods and test their usefulness in clinical practice, it is crucial to conduct independent validation on real clinical samples, which has yet to be properly delineated in the current literature.

OBJECTIVE

In this paper, we present our efforts to enable such clinical translational through the evaluation and comparison of two machine-learning methods for discrimination between dementia of Alzheimer's type (DAT) and Non-DAT controls.

METHODS

FDG-PET-based dementia scores were generated on an independent clinical sample whose clinical diagnosis was blinded to the algorithm designers. A feature-engineered approach (multi-kernel probability classifier) and a non-feature-engineered approach (3D convolutional neural network) were analyzed. Both classifiers were pre-trained on cognitively normal subjects as well as subjects with DAT. These two methods provided a probabilistic dementia score for this previously unseen clinical data. Performance of the algorithms were compared against ground-truth dementia rating assessed by experienced nuclear physicians.

RESULTS

Blinded clinical evaluation on both classifiers showed good separation between the cognitively normal subjects and the patients diagnosed with DAT. The non-feature-engineered dementia score showed higher sensitivity among subjects whose diagnosis was in agreement between the machine-learning models, while the feature-engineered approach showed higher specificity in non-consensus cases.

CONCLUSION

In this study, we demonstrated blinded evaluation using data from an independent clinical sample for assessing the performance in DAT classification models in a clinical setting. Our results showed good generalizability for two machine-learning approaches, marking an important step for the translation of pre-trained machine-learning models into clinical practice.

Use of Direct-Acting Antiviral Agents and Survival Among Medicare Beneficiaries with Dementia and Chronic Hepatitis C

BACKGROUND

Many patients with Alzheimer's disease and related dementia (ADRD) have chronic hepatitis C due to the high prevalence of both conditions among elderly populations. Direct-acting antivirals (DAAs) are effective in treating hepatitis C virus (HCV). However, the complexity of ADRD care may affect DAA use and outcomes among patients with HCV and ADRD. Little information exists on uptake of DAAs, factors associated with DAA use, and health benefits of DAAs among patients with HCV and ADRD.

OBJECTIVE

To examine use and survival benefits of DAAs in Medicare patients with HCV and ADRD.

METHODS

The study included Medicare patients with HCV between 2014 and 2017. We estimated Cox proportional hazards regressions to examine the association between having ADRD and DAA use, and the relation between DAA use and survival among patients with HCV and ADRD.

RESULTS

The adjusted hazard of initiating a DAA was 50% lower in patients with ADRD than those without ADRD (adjusted HR = 0.50, 95% CI: 0.46-0.54). The hazard of DAA use among ADRD patients with behavioral disturbances was 68% lower than non-ADRD patients (adjusted HR = 0.32, 95% CI: 0.28-0.37). DAA treatment was associated with a significant reduction in mortality among ADRD patients (adjusted HR = 0.52, 95% CI: 0.44-0.61).

CONCLUSION

The rate of DAA treatment in patients with HCV and ADRD was low, particularly among those with behavioral disturbance. The survival benefits of DAA treatment for patients with ADRD were substantial.

Past, present and future EEG in the clinical workup of dementias

Electroencephalography (EEG), as non-invasive, global measure of neuronal activity, is a prime candidate functional marker of synapse dysfunction and loss in dementias. Nevertheless, EEG currently has no established role in the clinical workup of individual patients. This opinion paper presents our critical view on why EEG has so far failed to keep its promise, and where we believe EEG will be clinically useful for patients threatened with cognitive decline in the future. Individual EEGs are an integral outcome of many causally intermixing upstream factors contributing to dementia. Therefore, EEG cannot become a clinically useful "simple" stand-alone biomarker of some pathognomic accumulations of specific brain proteins, but rather offer unique opportunities for more comprehensive and richly faceted insights into the functional status of brain systems. EEG may thus remain an essential window into the brain when it comes to the at-risk and presymptomatic phases of dementias, where it can be uniquely informative about concepts such as burdens of plasticity and repair, cognitive reserve, and sleep. Jointly with rapid gains in usability, portability, machine learning, closed loop systems, and understanding of the role of EEG-based sleep stages for memory and brain repair, EEG may come to keep its initial promise after all.

Predicting the outcome of non-pharmacological treatment for patients with dementia-related mild cognitive impairment

Dementia is a progressive cognitive syndrome, with few effective pharmacological treatments that can slow its progress. Hence, non-pharmacological treatments (NPTs) play an important role in improving patient symptoms and quality of life. Designing the optimal personalised NPT strategy relies on objectively and quantitatively predicting the treatment outcome. Magnetoencephalography (MEG) findings can reflect the cognitive status of patients with dementia, and thus potentially predict NPT outcome. In the present study, 16 participants with cognitive impairment underwent NPT for several months. Their cognitive performance was evaluated based on the Mini-Mental State Examination and the Alzheimer's Disease Assessment Scale - Cognitive at the beginning and end of the NPT period, while resting-state brain activity was evaluated using MEG during the NPT period. Our results showed that the spectral properties of MEG signals predicted the changes in cognitive performance scores. High frequency oscillatory intensity at the right superior frontal gyrus medial segment, opercular part of the inferior frontal gyrus, triangular part of the inferior frontal gyrus, post central gyrus, and angular gyrus predicted the changes in cognitive performance scores. Thus, resting-state brain activity may be a powerful tool in designing personalised NPT.

A preliminary study of cerebral blood flow, aging and dementia in people with Down syndrome

BACKGROUND

People with Down syndrome (DS) develop Alzheimer's disease (AD) at an earlier age of onset than those with sporadic AD. AD neuropathology is typically present in DS by 40 years of age with an onset of dementia approximately 10 years later. This early onset is due to the overexpression of amyloid precursor protein from the third copy of chromosome 21. Cerebrovascular neuropathology is thought to contribute in 40-60% of cases sporadic AD. However, the vascular contribution to dementia in people with DS has been relatively unexplored. We hypothesised that vascular perfusion is compromised in older adults with DS relative to younger individuals and is further exacerbated in those with dementia.

METHOD

Cerebral blood flow (CBF) was measured using pulsed arterial spin labelling in 35 cognitively characterised adults with DS (26-65 years). DS participants were also compared with 15 control subjects without DS or dementia (26-65 years). Linear regression evaluated the difference in CBF across groups and diagnosis along with assessing the association between CBF and cognitive measures within the DS cohort.

RESULTS

Cerebral blood flow was significantly lower among DS participants with probable AD compared with controls (P = 0.02) and DS participants with no dementia (P = 0.01). Within the DS cohort, CBF was significantly associated with the Severe Impairment Battery (SIB) measure and the Dementia Questionnaire for People with Learning Disabilities (DLD) rating (F_3,25  = 5.13; P = 0.007). Both the SIB (β = 0.74; t = 2.71; P = 0.01) and DLD (β = -0.96; t = -3.87; P < 0.001) indicated greater impairment as global CBF decreased. Age was significantly associated with CBF among participants with DS. There was a non-linear effect of age, whereby CBF declined more rapidly after 45 years of age.

CONCLUSIONS

This preliminary study of CBF in DS indicates that cerebrovascular pathology may be a significant contributor to dementia in DS. CBF was associated with diagnosis, cognition and age. Notably, CBF decreases at a greater rate after age 45 and may represent a significant prodromal event in AD progression.

How Can Hearing Loss Cause Dementia?

Epidemiological studies identify midlife hearing loss as an independent risk factor for dementia, estimated to account for 9% of cases. We evaluate candidate brain bases for this relationship. These bases include a common pathology affecting the ascending auditory pathway and multimodal cortex, depletion of cognitive reserve due to an impoverished listening environment, and the occupation of cognitive resources when listening in difficult conditions. We also put forward an alternate mechanism, drawing on new insights into the role of the medial temporal lobe in auditory cognition. In particular, we consider how aberrant activity in the service of auditory pattern analysis, working memory, and object processing may interact with dementia pathology in people with hearing loss. We highlight how the effect of hearing interventions on dementia depends on the specific mechanism and suggest avenues for work at the molecular, neuronal, and systems levels to pin this down.

Nonparametric time series summary statistics for high-frequency accelerometry data from individuals with advanced dementia

Accelerometry data has been widely used to measure activity and the circadian rhythm of individuals across the health sciences, in particular with people with advanced dementia. Modern accelerometers can record continuous observations on a single individual for several days at a sampling frequency of the order of one hertz. Such rich and lengthy data sets provide new opportunities for statistical insight, but also pose challenges in selecting from a wide range of possible summary statistics, and how the calculation of such statistics should be optimally tuned and implemented. In this paper, we build on existing approaches, as well as propose new summary statistics, and detail how these should be implemented with high frequency accelerometry data. We test and validate our methods on an observed data set from 26 recordings from individuals with advanced dementia and 14 recordings from individuals without dementia. We study four metrics: Interdaily stability (IS), intradaily variability (IV), the scaling exponent from detrended fluctuation analysis (DFA), and a novel nonparametric estimator which we call the proportion of variance (PoV), which calculates the strength of the circadian rhythm using spectral density estimation. We perform a detailed analysis indicating how the time series should be optimally subsampled to calculate IV, and recommend a subsampling rate of approximately 5 minutes for the dataset that has been studied. In addition, we propose the use of the DFA scaling exponent separately for daytime and nighttime, to further separate effects between individuals. We compare the relationships between all these methods and show that they effectively capture different features of the time series.

Why dizziness is likely to increase the risk of cognitive dysfunction and dementia in elderly adults

Dementia is recognised to be one of the most challenging diseases facing society, both now and in the future, with its prevalence estimated to increase substantially by 2050. The potential contributions of age-related sensory deficits have attracted little attention until recently, when a landmark study suggested that hearing loss could be a greater risk factor for dementia than hypertension, obesity, smoking, depression, physical inactivity or social isolation. Over the last decade, evidence has been gradually accumulating to suggest that the other part of the inner ear, the balance organs or 'vestibular system', might also be important in the development of cognitive dysfunction and dementia. Increasing evidence suggests that dizziness associated with vestibular dysfunction, a common reason for patients consulting their GPs, increases the risk of cognitive dysfunction, including dementia, and our understanding of the basic neurobiology of this sensory system supports this view. This paper aims to review and critically evaluate the relevant evidence.

Thermal Sensation in Older People with and without Dementia Living in Residential Care: New Assessment Approaches to Thermal Comfort Using Infrared Thermography

The temperature of the indoor environment is important for health and wellbeing, especially at the extremes of age. The study aim was to understand the relationship between self-reported thermal sensation and extremity skin temperature in care home residents with and without dementia. The Abbreviated Mental Test (AMT) was used to discriminate residents to two categories, those with, and those without, dementia. After residents settled and further explanation of the study given (approximately 15 min), measurements included: tympanic membrane temperature, thermal sensation rating and infrared thermal mapping of non-dominant hand and forearm. Sixty-nine afebrile adults (60-101 years of age) were studied in groups of two to five, in mean ambient temperatures of 21.4-26.6 °C (median 23.6 °C). Significant differences were observed between groups; thermal sensation rating (p = 0.02), tympanic temperature (p = 0.01), fingertip skin temperature (p = 0.01) and temperature gradients; fingertip-wrist p = 0.001 and fingertip-distal forearm, p = 0.001. Residents with dementia were in significantly lower air temperatures (p = 0.001). Although equal numbers of residents per group rated the environment as 'neutral' (comfortable), resident ratings for 'cool/cold' were more frequent amongst those with dementia compared with no dementia. In parallel, extremity (hand) thermograms revealed visual temperature demarcation, variously across fingertip, wrist, and forearm commensurate with peripheral vasoconstriction. Infrared thermography provided a quantitative and qualitative method to measure and observe hand skin temperature across multiple regions of interest alongside thermal sensation self-report. As an imaging modality, infrared thermography has potential as an additional assessment technology with clinical utility to identify vulnerable residents who may be unable to communicate verbally, or reliably, their satisfaction with indoor environmental conditions.

Characterization of Tauopathy in a Rat Model of Post-Stroke Dementia Combining Acute Infarct and Chronic Cerebral Hypoperfusion

Post-stroke dementia (PSD) is a major neurodegenerative consequence of stroke. Tauopathy has been reported in diverse neurodegenerative diseases. We investigated the cognitive impairment and pathomechanism associated with tauopathy in a rat model of PSD by modeling acute ischemic stroke and underlying chronic cerebral hypoperfusion (CCH). We performed middle cerebral artery occlusion (MCAO) surgery in rats to mimic acute ischemic stroke, followed by bilateral common carotid artery occlusion (BCCAo) surgery to mimic CCH. We performed behavioral tests and focused on the characterization of tauopathy through histology. Parenchymal infiltration of cerebrospinal fluid (CSF) tracers after intracisternal injection was examined to evaluate glymphatic function. In an animal model of PSD, cognitive impairment was aggravated when BCCAo was combined with MCAO. Tauopathy, manifested by tau hyperphosphorylation, was prominent in the peri-infarct area when CCH was combined. Synergistic accentuation of tauopathy was evident in the white matter. Microtubules in the neuronal axon and myelin sheath showed partial colocalization with the hyperphosphorylated tau, whereas oligodendrocytes showed near-complete colocalization. Parenchymal infiltration of CSF tracers was attenuated in the PSD model. Our experimental results suggest a hypothesis that CCH may aggravate cognitive impairment and tau hyperphosphorylation in a rat model of PSD by interfering with tau clearance through the glymphatic system. Therapeutic strategies to improve the clearance of brain metabolic wastes, including tau, may be a promising approach to prevent PSD after stroke.

Neuronal Oscillations on Evolving Networks: Dynamics, Damage, Degradation, Decline, Dementia, and Death

Neurodegenerative diseases, such as Alzheimer's or Parkinson's disease, show characteristic degradation of structural brain networks. This degradation eventually leads to changes in the network dynamics and degradation of cognitive functions. Here, we model the progression in terms of coupled physical processes: The accumulation of toxic proteins, given by a nonlinear reaction-diffusion transport process, yields an evolving brain connectome characterized by weighted edges on which a neuronal-mass model evolves. The progression of the brain functions can be tested by simulating the resting-state activity on the evolving brain network. We show that while the evolution of edge weights plays a minor role in the overall progression of the disease, dynamic biomarkers predict a transition over a period of 10 years associated with strong cognitive decline.

Cognition and motor function: The gait and cognition pooled index

Background

There is a need for outcome measures with improved responsiveness to changes in pre-dementia populations. Both cognitive and motor function play important roles in neurodegeneration; motor function decline is detectable at early stages of cognitive decline. This proof of principle study used a Pooled Index approach to evaluate improved responsiveness of the predominant outcome measure (ADAS-Cog: Alzheimer’s Disease Assessment Scale-Cognitive Subscale) when assessment of motor function is added.

Methods

Candidate Pooled Index variables were selected based on theoretical importance and pairwise correlation coefficients. Kruskal-Wallis and Mann-Whitney U tests assessed baseline discrimination. Standardized response means assessed responsiveness to longitudinal change.

Results

Final selected variables for the Pooled Index include gait velocity, dual-task cost of gait velocity, and an ADAS-Cog-Proxy (statistical approximation of the ADAS-Cog using similar cognitive tests). The Pooled Index and ADAS-Cog-Proxy scores had similar ability to discriminate between pre-dementia syndromes. The Pooled Index demonstrated trends of similar or greater responsiveness to longitudinal decline than ADAS-Cog-Proxy scores.

Conclusion

Adding motor function assessments to the ADAS-Cog may improve responsiveness in pre-dementia populations.

Dementia- and mild cognitive impairment-inclusive exercise: Perceptions, experiences, and needs of community exercise providers

PURPOSE

For persons who are at risk for, or living with, dementia exercise is recommended, yet many become or remain inactive. Exercise providers play a vital role in promoting and facilitating exercise in these groups by recognizing and being responsive to the needs of persons with mild cognitive impairment (MCI) or dementia in exercise programming. The objective of this study was to explore the experiences, perceptions, and needs of community exercise providers regarding dementia.

MATERIALS & METHODS

Five focus groups were held with community exercise providers (n = 30) who deliver exercise to older adults (≥55 years) in municipal, non-profit, for profit, or academic settings.

RESULTS

Three themes were developed: (1) Unique experiences and diverse perceptions: suggests unique personal experiences with MCI and dementia inform distinct perceptions of dementia; (2) Dementia-Inclusive Practices: learning as you go and adapting for the individual: reflects exercise providers' approaches to recognizing and accommodating individuals' unique abilities and preferences; (3) Training and Best Practices, with Flexibility: identifies exercise providers' desires for MCI- and dementia-specific knowledge and training strategies, which need to recognize dementia heterogeneity between and within persons over time.

CONCLUSIONS

These findings highlight a willingness of exercise providers to support dementia-inclusive exercise, but recognize they have minimal training and lack educational resources to do so. Formal training resources may enhance exercise accessibility and participation for persons with MCI or dementia.

Association of Sleep Electroencephalography-Based Brain Age Index With Dementia

IMPORTANCE

Dementia is an increasing cause of disability and loss of independence in the elderly population yet remains largely underdiagnosed. A biomarker for dementia that can identify individuals with or at risk for developing dementia may help close this diagnostic gap.

OBJECTIVE

To investigate the association between a sleep electroencephalography-based brain age index (BAI), the difference between chronological age and brain age estimated using the sleep electroencephalogram, and dementia.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cross-sectional study of 9834 polysomnograms, BAI was computed among individuals with previously determined dementia, mild cognitive impairment (MCI), or cognitive symptoms but no diagnosis of MCI or dementia, and among healthy individuals without dementia from August 22, 2008, to June 4, 2018. Data were analyzed from November 15, 2018, to June 24, 2020.

EXPOSURE

Dementia, MCI, and dementia-related symptoms, such as cognitive change and memory impairment.

MAIN OUTCOMES AND MEASURES

The outcome measures were the trend in BAI when moving from groups ranging from healthy, to symptomatic, to MCI, to dementia and pairwise comparisons of BAI among these groups.

FINDINGS

A total of 5144 sleep studies were included in BAI examinations. Patients in these studies had a median (interquartile range) age of 54 (43-65) years, and 3026 (59%) were men. The patients included 88 with dementia, 44 with MCI, 1075 who were symptomatic, and 2336 without dementia. There was a monotonic increase in mean (SE) BAI from the nondementia group to the dementia group (nondementia: 0.20 [0.42]; symptomatic: 0.58 [0.41]; MCI: 1.65 [1.20]; dementia: 4.18 [1.02]; P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that a sleep-state electroencephalography-based BAI shows promise as a biomarker associated with progressive brain processes that ultimately result in dementia.

Association of Alcohol-Induced Loss of Consciousness and Overall Alcohol Consumption With Risk for Dementia

IMPORTANCE

Evidence on alcohol consumption as a risk factor for dementia usually relates to overall consumption. The role of alcohol-induced loss of consciousness is uncertain.

OBJECTIVE

To examine the risk of future dementia associated with overall alcohol consumption and alcohol-induced loss of consciousness in a population of current drinkers.

DESIGN, SETTING, AND PARTICIPANTS

Seven cohort studies from the UK, France, Sweden, and Finland (IPD-Work consortium) including 131 415 participants were examined. At baseline (1986-2012), participants were aged 18 to 77 years, reported alcohol consumption, and were free of diagnosed dementia. Dementia was examined during a mean follow-up of 14.4 years (range, 12.3-30.1). Data analysis was conducted from November 17, 2019, to May 23, 2020.

EXPOSURES

Self-reported overall consumption and loss of consciousness due to alcohol consumption were assessed at baseline. Two thresholds were used to define heavy overall consumption: greater than 14 units (U) (UK definition) and greater than 21 U (US definition) per week.

MAIN OUTCOMES AND MEASURES

Dementia and alcohol-related disorders to 2016 were ascertained from linked electronic health records.

RESULTS

Of the 131 415 participants (mean [SD] age, 43.0 [10.4] years; 80 344 [61.1%] women), 1081 individuals (0.8%) developed dementia. After adjustment for potential confounders, the hazard ratio (HR) was 1.16 (95% CI, 0.98-1.37) for consuming greater than 14 vs 1 to 14 U of alcohol per week and 1.22 (95% CI, 1.01-1.48) for greater than 21 vs 1 to 21 U/wk. Of the 96 591 participants with data on loss of consciousness, 10 004 individuals (10.4%) reported having lost consciousness due to alcohol consumption in the past 12 months. The association between loss of consciousness and dementia was observed in men (HR, 2.86; 95% CI, 1.77-4.63) and women (HR, 2.09; 95% CI, 1.34-3.25) during the first 10 years of follow-up (HR, 2.72; 95% CI, 1.78-4.15), after excluding the first 10 years of follow-up (HR, 1.86; 95% CI, 1.16-2.99), and for early-onset (<65 y: HR, 2.21; 95% CI, 1.46-3.34) and late-onset (≥65 y: HR, 2.25; 95% CI, 1.38-3.66) dementia, Alzheimer disease (HR, 1.98; 95% CI, 1.28-3.07), and dementia with features of atherosclerotic cardiovascular disease (HR, 4.18; 95% CI, 1.86-9.37). The association with dementia was not explained by 14 other alcohol-related conditions. With moderate drinkers (1-14 U/wk) who had not lost consciousness as the reference group, the HR for dementia was twice as high in participants who reported having lost consciousness, whether their mean weekly consumption was moderate (HR, 2.19; 95% CI, 1.42-3.37) or heavy (HR, 2.36; 95% CI, 1.57-3.54).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that alcohol-induced loss of consciousness, irrespective of overall alcohol consumption, is associated with a subsequent increase in the risk of dementia.

Managing the Burden of Dementia Related Delusions and Hallucinations

Identify the burden experienced by patients with dementia-related delusions and hallucinations. Assess patients with dementia for the presence of delusions and hallucinations. Individualize treatment in patients with dementia-related delusions and hallucinations. Align treatment of patients with Parkinson's psychosis with current recommendations.

Education and adolescent cognitive ability as predictors of dementia in a cohort of Danish men

BACKGROUND

An association between education and dementia is well-established but it is unclear whether education is associated with dementia after accounting for early life cognitive ability and whether there is a joint effect, such that the risk associated with one of the exposures depends on the value of the other. We examined separate and joint associations of adolescent cognitive ability and educational attainment with risk of dementia among Danish men born between 1939 and 1959.

METHODS

Men (N = 477,421) from the Danish Conscription Database were followed for dementia from the age 60 for up to 17 years via patient and prescription registry linkages. Exposure measures included cognitive ability assessed at the conscript board examination around age 18 and highest educational level (low: 0-10 year, medium: 10-13 years, high: ≥13 years) at age 30 from registry records. Associations with dementia diagnosis were estimated in Cox proportional hazards models adjusted for birth year and age at conscript board examination. Interaction was assessed on the multiplicative scale by including a product term between the two exposure measures and on the additive scale by calculating relative excess risk due to interaction (RERI) between different levels of the exposure measures.

RESULTS

Compared to men in the high education group hazard ratio [HR] for men in the medium and low group were 1.21 (95% confidence interval [CI]: 1.13, 1.30) and 1.34 (95% CI: 1.24, 1.45), respectively when not adjusting for cognitive ability. Additional adjustment for cognitive ability attenuated the magnitude of the associations, but they remained significant (education medium: HR = 1.10, 95% CI: 1.02, 1.19 and education low: HR = 1.12, 95% CI: 1.02, 1.22). A 10% higher cognitive ability score was associated with a 3.8% lower hazard of dementia (HR = 0.962; 95% CI: 0.957, 0.967), and the magnitude of the association only changed marginally after adjustment for education. Men in the low education group with relatively low cognitive ability were identified as a high-risk subgroup for dementia. The increased risk associated with exposure to both risk factors did, however, not significantly depart from the sum of risk experienced by men only exposed to one of the risk factors (estimates of RERI were not significantly different from 0) and no significant evidence of either additive or multiplicative interactions was found.

CONCLUSIONS

In conclusion, the results suggest that education and cognitive ability protect against the risk of dementia independently of one another and that increases in educational attainment may at least partially offset dementia risk due to low cognitive ability.

Pituitary adenylate cyclase-activating polypeptide: Protective effects in stroke and dementia

Evidence shows that pituitary adenylate cyclase-activating polypeptide (PACAP) improves stroke outcomes and dementia. The blood-brain barrier (BBB) controls the peptide and regulatory protein exchange between the central nervous system and the blood; the transport of these regulatory substances across the BBB has been altered in animal models of stroke and Alzheimer's disease (AD). PACAP is a powerful neurotrophin that can cross the BBB, which may aid in the therapy of neurodegenerative diseases, including stroke and AD. PACAP may function as a potential drug in the treatment, prevention, or management of stroke and AD and other neurodegenerative conditions. Here, we review the effects of PACAP in studies on stroke and dementias.

Valuing the AD-5D Dementia Utility Instrument: An Estimation of a General Population Tariff

OBJECTIVE

This paper reports on the valuation of quality-of-life states in the Alzheimer's Disease Five Dimensions (AD-5D) instrument in a representative sample of the general population in Australia using the discrete-choice experiment with duration (DCE_TTO) elicitation technique.

METHOD

A DCE with 200 choice sets of two quality-of-life (QoL) state-duration combinations blocked into 20 survey versions, with ten choice sets in each version, was designed and administered online to a sample representative of the Australian population. Two additional choice sets comprising internal consistency and dominance checks were included in each survey version. A range of model specifications investigating preferences with respect to duration and interactions between AD-5D dimension levels were estimated. Utility weights were developed, with estimated coefficients transformed to the 0 (being dead) to 1 (full health) scale, suitable for the calculation of quality-adjusted life-year (QALY) weights for use in economic evaluation.

RESULTS

In total, 1999 respondents completed the choice experiment. Overall, respondents were slightly better educated and had higher annual incomes than the Australian general population. The estimation results from different specifications and models were broadly consistent with the monotonic nature of the AD-5D: utility increased with increased life expectancy and decreased as the severity level for each dimension worsened. A utility value set was generated for the calculation of utilities for all QoL states defined by the AD-5D descriptive system.

CONCLUSION

The DCE-based utility value set is now available to use to generate QALYs for the economic evaluation of treatments and interventions targeting people with dementia and/or their family caregivers.

Factors influencing cognitive performance after 1-year treatment with direct oral anticoagulant in patients with atrial fibrillation and previous ischemic stroke: a pilot study

Anticoagulant treatment as stroke prevention, particularly direct oral anticoagulant (DOAC), may reduce the risk of dementia in patients with atrial fibrillation (AF). We aimed to assess factors influencing cognitive performance after 1-year treatment with DOAC in patients with AF and previous ischemic stroke. We recruited 33 ischemic stroke patients who were discharged from Verona Stroke Unit with diagnosis of AF and prescription of treatment with DOAC. For each cognitive test, we estimated the effect of T0 (first session) variables on T1 (1-year session) cognitive performance using ordinal logistic regression fitted to a 1 point-shift from 4 to 0 on ESs. The effect of T0 clinical variables was presented as odds ratio (OR) with 95% confidence interval (CI) after adjustment for T0 total score of the corresponding cognitive test. Sustained AF (OR: 4.259, 95% CI 1.071-16.942) and ischemic heart disease (OR: 6.654, 95% CI 1.329-33.300) showed a significant effect on T1 MoCA Test; congestive heart failure on T1 RAVLT Immediate recall (OR: 9.128, 95% CI 1.055-78.995), T1 RAVLT Delayed recall (OR: 7.134, 95% CI 1.214-52.760), and T1 Trail Making Test (Part A) (OR: 16.989, 95% CI 1.765-163.565); sustained AF (OR: 5.055, 95% CI 1.224-20.878) and hyperlipidemia (OR: 4.764, 95% CI 1.175-19.310) on T1 Digit span forward Test; ischemic heart disease (aOR: 8.460, 95% CI 1.364-52.471) on T1 Stroop Color and Word Test (time); Dabigatran use (aOR: 0.084, 95% CI 0.013-0.544) on FAB; age ≥ 75 years (aOR: 0.058, 95% CI 0.006-0.563) and hyperlipidemia (aOR: 5.809, 95% CI 1.059-31.870) on T1 Phonemic word fluency Test; female sex (aOR: 6.105, 95% CI 1.146-32.519), hyperlipidemia (aOR: 21.099, 95% CI 2.773-160.564), total Modified Fazekas Scale score > 1 (aOR: 78.530, 95% CI 3.131-1969.512) on Semantic word fluency Test. Sustained AF, ischemic heart disease, congestive heart failure, hyperlipidemia, and female sex were the factors influencing cognitive performance after 1-year treatment with DOAC in patients with AF and previous ischemic stroke. Modified Fazekas Scale score in the first session was the only radiological variable that had a significant effect on cognitive performance.

What older adults do with the results of dementia screening programs

Introduction

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

Methods

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

Results

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

Discussion

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

Approach to the Older Adult With New Cognitive Symptoms

Dementia affects nearly 50 million people worldwide, translating into one new case every 3 seconds. Dementia syndrome is one of the leading causes of disability among older adults, yet it remains vastly underdiagnosed. A timely diagnosis of dementia is essential to ensuring optimal care and support of individuals and their loved ones. Although there is no single test for dementia, health care providers can use a structured approach to the workup and management of new cognitive symptoms. Comprehensive MEDLINE and PubMed searches were performed to develop an unbiased, practical diagnostic approach to these symptoms. This review guides primary care providers in the workup, diagnosis, delivery, and initial management of patients presenting with new cognitive symptoms.

Working status of caregivers for people with dementia: Analysis data from a Japanese Nationwide Survey

BACKGROUND

The prevalence of dementia has increased rapidly in Japan, while the proportion of the population accounted for by working-age individuals is facing a sharp decline. Optimizing the balance between work and caregiving for persons with dementia is a major public health issue.

AIMS

Using a nationally representative sample, this study investigated the working status of caregivers (CGs) for elderly people (care recipients) with dementia (CRDs) and assessed the effects of sociodemographic factors on this status.

METHODS

Data were obtained from the 2013 Comprehensive Survey of the Living Conditions for CRDs and CGs (the latter aged 65 years or less). Individual data of CRDs and CGs were linked, and 452 pairs were extracted. The Japanese version of the Kessler 6 (K6) with a cut-off point of 13 was used to assess general psychological distress among CGs. Multivariable logistic regression analysis with the forward selection method was used to identify the predictors of their working status.

RESULTS

Overall, the mean age of CGs was 57.1 ± 6.8 years, with 57.5% (260/452) performing paid work. Male sex, higher educational attainment, and having their own house were associated with having paid work for CGs, while higher age, spending almost all day performing nursing care, and participation in helping with toilet activities and laundry were associated with not performing paid work.

CONCLUSIONS

Several sociodemographic factors, including nursing care-related factors, are associated with the employment status of CGs. Further research should examine detailed information on CRDs' activities of daily living, behavioral and psychological symptoms, medical service use, and social support to strengthen the system of supportive services for both CRDs and their CGs.