Variation in Home Healthcare Use by Dementia Status Among a National Cohort of Older Adults

BACKGROUND

Medicare-funded home healthcare (HHC) delivers skilled nursing, therapy, and related services through visits to the patient's home. Nearly one-third (31%) of HHC patients have diagnosed dementia, but little is currently known regarding how HHC utilization and care delivery differ for persons living with dementia (PLwD).

METHODS

We drew on linked 2012-2018 Health and Retirement Study and Medicare claims for a national cohort of 1 940 community-living older adults. We described differences in HHC admission, length of stay, and referral source by patient dementia status and used weighted, multivariable logistic and negative binomial models to estimate the relationship between dementia and HHC visit type and intensity while adjusting for sociodemographic characteristics, health and functional status, and geographic/community factors.

RESULTS

PLwD had twice the odds of using HHC during a 2-year observation period, compared to those without dementia (odds ratio [OR]: 2.03; p < .001). They were more likely to be referred to HHC without a preceding hospitalization (49.4% vs 32.1%; p < .001) and incurred a greater number of HHC episodes (1.4 vs 1.0; p < .001) and a longer median HHC length of stay (55.8 days vs 40.0 days; p < .001). Among post-acute HHC patients, PLwD had twice the odds of receiving social work services (unadjusted odds ratio [aOR]: 2.15; p = .008) and 3 times the odds of receiving speech-language pathology services (aOR: 2.92; p = .002).

CONCLUSIONS

Findings highlight HHC's importance as a care setting for community-living PLwD and indicate the need to identify care delivery patterns associated with positive outcomes for PLwD and design tailored HHC clinical pathways for this patient subpopulation.

Clinically Important Benefits and Harms of Monoclonal Antibodies Targeting Amyloid for the Treatment of Alzheimer Disease: A Systematic Review and Meta-Analysis

PURPOSE

We conducted a meta-analysis to evaluate clinically meaningful benefits and harms of monoclonal antibodies targeting amyloid in patients with Alzheimer dementia.

METHODS

We searched PubMed, Cochrane CENTRAL, and 5 trial registries, as well as the reference lists of identified studies. We included randomized controlled trials comparing a monoclonal antibody with placebo at a dose consistent with that used in phase 3 trials or for Food and Drug Administration approval. Studies had to report at least 1 clinically relevant benefit or harm. Data were extracted independently by at least 2 researchers for random effects meta-analysis. Changes in cognitive and functional scales were compared between groups, and each difference was assessed to determine if it met the minimal clinically important difference (MCID).

RESULTS

We identified 19 publications with 23,202 total participants that evaluated 8 anti-amyloid antibodies. There were small improvements over placebo in the Alzheimer's Disease Assessment Scale (ADAS)-Cog-11 to -14 score (standardized mean difference = -0.07; 95% CI, -0.10 to -0.04), Mini Mental State Examination score (0.32 points; 95% CI, 0.13 to 0.50), and Clinical Dementia Rating-Sum of Boxes scale score (mean difference =-0.18 points; 95% CI, -0.34 to -0.03), and the combined functional scores (standardized mean difference = 0.09; 95% CI, 0.05 to 0.13). None of the changes, including those for lecanemab, aducanumab, and donanemab, exceeded the MCID. Harms included significantly increased risks of amyloid-related imaging abnormalities (ARIA)-edema (relative risk [RR] = 10.29; number needed to harm [NNH] = 9), ARIA-hemorrhage (RR = 1.74; NNH = 13), and symptomatic ARIA-edema (RR = 24.3; NNH = 86).

CONCLUSIONS

Although monoclonal antibodies targeting amyloid provide small benefits on cognitive and functional scales in patients with Alzheimer dementia, these improvements are far below the MCID for each outcome and are accompanied by clinically meaningful harms.

A Preliminary Study on the Potential Protective Role of the Antioxidative Stress Markers of Cognitive Impairment: Glutathione and Glutathione Reductase

Objective

: To investigate the relationship between reduced glutathione (GSH), a key molecule of the antioxidant defense system in the blood, and glutathione reductase (GR), which reduces oxidized glutathione (glutathione disulfide [GSSG]) to GSH and maintains the redox balance, with the prevalence of Alzheimer's dementia and cognitive decline.

Methods

: In all, 20 participants with Alzheimer's dementia who completed the third follow-up clinical evaluation over 6 years were selected, and 20 participants with normal cognition were selected after age and sex matching. The GSH and GR concentrations were the independent variables. Clinical diagnosis and neurocognitive test scores were the dependent variables indicating cognitive status.

Results

: The higher the level of GR, the greater the possibility of having normal cognition than of developing Alzheimer's dementia. Additionally, the higher the level of GR, the higher the neurocognitive test scores. However, this association was not significant for GSH. After 6 years, the conversion rate from normal cognition to cognitive impairment was significantly higher in the lower 50th percentile of the GR group than in the upper 50th percentile.

Conclusion

: The higher the GR, the lower the prevalence of Alzheimer's dementia and incidence of cognitive impairment and the higher the cognitive test scores. Therefore, GR is a potential protective biomarker against Alzheimer's dementia and cognitive decline.

Clozapine for the treatment of aggressiveness and agitation in advanced dementia

BACKGROUND

Distressing behavioural symptoms, particularly agitation and aggressiveness, remain a difficult problem in everyday clinical practice in the treatment of multimorbid patients with dementia. Clozapine may be an effective therapeutic alternative in this context.

METHODS

In a retrospective study, patients who had a diagnosis of dementia and had been treated in a specialized geriatric psychiatry unit with clozapine between August 2018 and February 2022 were included, and medical records were systematically reviewed. The Clinical Global Impressions Scale was used to assess improvement, and the Pittsburgh Agitation Scale for symptom reduction. In addition, side effects and clinical features were documented in detail.

RESULTS

A total of 31 patients (median age 82 years) were identified with a mean clozapine dose of 47.2 (SD 35.6) mg. A total of 13 patients tolerated clozapine very well, 10 showed tolerable side effects, and in 10 patients side effects were the reason for stopping clozapine. Behavioural symptoms improved significantly, as indicated by the assessment scores.

CONCLUSIONS

In summary, clozapine was effective and well tolerated in 23 patients, suggesting that low-dose clozapine may help to alleviate the suffering of difficult-to-treat multimorbid patients with advanced dementia and their caregivers. However, particular attention should be paid to adverse drug reactions, especially in patients with cardiovascular and pulmonary impairment.

Clinical, imaging, and biomarker evidence of amyloid- and tau-related neurodegeneration in late-onset epilepsy of unknown etiology

Accumulating evidence suggests amyloid and tau-related neurodegeneration may play a role in development of late-onset epilepsy of unknown etiology (LOEU). In this article, we review recent evidence that epilepsy may be an initial manifestation of an amyloidopathy or tauopathy that precedes development of Alzheimer's disease (AD). Patients with LOEU demonstrate an increased risk of cognitive decline, and patients with AD have increased prevalence of preceding epilepsy. Moreover, investigations of LOEU that use CSF biomarkers and imaging techniques have identified preclinical neurodegeneration with evidence of amyloid and tau deposition. Overall, findings to date suggest a relationship between acquired, non-lesional late-onset epilepsy and amyloid and tau-related neurodegeneration, which supports that preclinical or prodromal AD is a distinct etiology of late-onset epilepsy. We propose criteria for assessing elevated risk of developing dementia in patients with late-onset epilepsy utilizing clinical features, available imaging techniques, and biomarker measurements. Further research is needed to validate these criteria and assess optimal treatment strategies for patients with probable epileptic preclinical AD and epileptic prodromal AD.

Therapeutic Implications of Renin-Angiotensin System Modulators in Alzheimer's Dementia

The Renin-Angiotensin System (RAS) has attracted considerable interest beyond its traditional cardiovascular role due to emerging data indicating its potential involvement in neurodegenerative diseases, including Alzheimer's dementia (AD). This review investigates the therapeutic implications of RAS modulators, specifically focusing on angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), and renin inhibitors in AD. ACEIs, commonly used for hypertension, show promise in AD by reducing angiotensin (Ang) II levels. This reduction is significant as Ang II contributes to neuroinflammation, oxidative stress, and β-amyloid (Aβ) accumulation, all implicated in AD pathogenesis. ARBs, known for vasodilation, exhibit neuroprotection by blocking Ang II receptors, improving cerebral blood flow and cognitive decline in AD models. Renin inhibitors offer a novel approach by targeting the initial RAS step, displaying anti-inflammatory and antioxidant effects that mitigate AD degeneration. Preclinical studies demonstrate RAS regulation's favorable impact on neuroinflammation, neuronal damage, cognitive function, and Aβ metabolism. Clinical trials on RAS modulators in AD are limited, but with promising results, ARBs being more effective that ACEIs in reducing cognitive decline. The varied roles of ACEIs, ARBs, and renin inhibitors in RAS modulation present a promising avenue for AD therapeutic intervention, requiring further research to potentially transform AD treatment strategies.

Overall and cause-specific mortality in patients with dementia: a population-based cohort study in Taiwan

OBJECTIVES

Information regarding the underlying causes of death (UCODs) and standardized mortality ratio (SMR) of dementia is instrumental in formulating medical strategies to prolong life in persons with dementia (PWD). We examined the leading UCODs among PWD and estimated the overall and cause-specific SMRs in relation to dementia in Taiwan.

METHODS

Data were retrieved from 2 national datasets: the Taiwan Death Registry and the medical claim datasets of the National Health Insurance program. The observed person-years for each study participant were counted from the date of cohort enrollment to either the date of death or the final day of 2016. Sex-specific and age-specific SMRs were then calculated.

RESULTS

The leading UCOD was circulatory disease, accounting for 26.0% of total deaths (n=3,505), followed by respiratory disease at 21.3% (n=2,875). PWD were at significantly increased risk of all-cause mortality (SMR, 2.01), with SMR decreasing with advancing age. A cause-specific analysis revealed that the highest SMRs were associated with nervous system diseases (SMR, 7.58) and mental, behavioral, and neurodevelopmental disorders (SMR, 4.80). Age appeared to modify SMR, suggesting that younger age at cohort enrollment was linked to higher SMRs for nearly all causes of mortality.

CONCLUSIONS

Circulatory and respiratory diseases were the leading UCODs among PWD. The particularly elevated mortality due to nervous system diseases and mental disorders suggests that allocating more resources to neurological and psychiatric services is warranted. The elevated SMRs of various UCODs among younger PWD underscore the need for clinicians to pay particular attention to the medical care provided to these patients.

Understanding Barriers Along the Patient Journey in Alzheimer's Disease Using Social Media Data

INTRODUCTION

We speculated that social media data from Alzheimer's disease (AD) stakeholders (patients, caregivers, and clinicians) could identify barriers along the patient journey in AD, and that insights gained may help devise strategies to remove barriers, and ultimately improve the patient journey.

METHODS

Our sample was drawn from a repository of social media posts extracted from 112 public sources between January 1998 and December 2021 using natural language processing text-mining algorithms. The patient journey was classified into three phases: (1) early signs/experiences (Early Signs); (2) screening/assessment/diagnosis (Screening); and (3) treatment/management (Treatment). In the Early Signs phase, issues/challenges derived from a conceptual AD identification framework (ADIF) were examined. In subsequent phases, behavioral/psychiatric challenges, access/barriers to health care, screening/diagnostic methods, and symptomatic treatments for AD were identified. Posts were classified by AD stakeholder type or disease stage, if possible.

RESULTS

We identified 225,977 AD patient journey-related social media posts. Anxiety was a predominant issue/challenge in all patient journey phases. In the Screening and Treatment phases combined, access/barriers to care were described in 16% of posts; unwillingness/resistance to seeking care was a major barrier (≥ 75% of access-related posts across all stakeholders). Commonly identified structural barriers (e.g., affordability/cost, geography/transportation/distance) were more common in patient/caregiver posts than clinician posts. Among Screening-related posts, imaging/scans were commonly mentioned by all stakeholders; biomarkers were more commonly mentioned by patients than clinicians. Treatment-related concerns were identified in 17% of stakeholder-specified posts that named pharmacological agents/classes for the symptomatic management of AD.

CONCLUSION

This descriptive analysis of out-of-clinic experiences reflected in AD social media posts found that unwillingness/resistance to seeking care was a key barrier, followed by structural barriers to health care, such as affordability/cost. Insights from the lived experiences of AD stakeholders are valuable and highlight the need to improve the patient journey in AD and ease patient and caregiver burden.

Impact of diagnosed (vs undiagnosed) dementia on family caregiving experiences

BACKGROUND

Most older adults with Alzheimer's disease and related dementias (ADRD) do not receive a timely formal diagnosis, although formal diagnosis is linked to improved outcomes. Little is known about how a recognized formal diagnosis impacts family caregivers, who provide crucial support for older adults experiencing ADRD.

METHODS

We analyzed 2017 National Health and Aging Trends Study and linked National Study of Caregiving data for a nationally representative sample of 724 (weighted n = 5,431,551) caregivers who assisted an older adult with probable dementia. Probable dementia was determined via previously validated composite measure. We modeled caregiver experiences as a function of recognized formal ADRD diagnosis using weighted, logistic regression and adjusting for the relevant older adult and caregiver characteristics.

RESULTS

Among caregivers who assisted an older adult with probable dementia, those assisting an individual with recognized formal ADRD diagnosis were significantly more likely to report emotional difficulty (aOR: 1.77; p = 0.03) and family disagreement over the older adult's care (aOR: 5.53; p = 0.03). They were also more likely to assist with communication during doctors' visits (aOR: 9.71; p < 0.001) and to receive caregiving-related training (aOR: 2.59; p = 0.01).

CONCLUSIONS

While a timely ADRD diagnosis may help ensure access to needed supports for older adult and caregiver alike, diagnosis must be linked to support as they navigate resultant complex emotions. Formal diagnosis is linked to caregiver integration with, and support from, the older adult's team of health care providers; therefore, reducing existing disparities in timely diagnosis is necessary to ensure all caregivers have equal access to support.

Validity of the Brief Assessment of Impaired Cognition case-finding instrument for identification of dementia subgroups and staging of dementia

BACKGROUND AND PURPOSE

The aims of this study were to examine the psychometric properties of the Brief Assessment of Impaired Cognition (BASIC) case-finding instrument in clinical settings focusing on (i) test-retest reliability, (ii) the discriminative validity of BASIC and its components for identification of Alzheimer disease (AD) dementia and non-AD dementia, and (iii) the association of expert clinical rating of cognitive status with BASIC performance.

METHODS

The test-retest reliability analysis was based on a sample of general practice patients (n = 59) retested with a mean interval of 19 days. Discriminative validity analyses and analysis of the association of cognitive status with BASIC performance were based on data from the primary validation study of BASIC in memory clinics.

RESULTS

The test-retest reliability of BASIC was high (r = 0.861). No significant difference in discriminative validity was found for identification of AD dementia (sensitivity = 0.99, specificity = 0.98) and non-AD dementia (sensitivity = 0.90, specificity = 0.98). All components of BASIC contributed to the high discriminative validity of both AD and non-AD dementia. BASIC performance was significantly correlated with expert clinical rating of the cognitive status of patients. A crude staging model for cognitive status using BASIC score intervals had superior classification accuracy (70%) compared to a Mini-Mental State Examination (MMSE) score range-based model (58% accuracy).

CONCLUSIONS

BASIC is a reliable and valid case-finding instrument for AD dementia and non-AD dementia in clinical settings. BASIC performance is significantly associated with the degree of cognitive impairment, and BASIC seems to be superior to MMSE for staging of impairment.

Trace elements and Alzheimer dementia in population-based studies: A bibliometric and meta-analysis

Alterations in the concentrations of trace elements may play a vital role in Alzheimer dementia progression. However, previous research results are inconsistent, and there is still a lack of review on the relationship between all the studied-trace elements and AD from various perspectives of population-based studies. In this study, we systematically reviewed previous population-based studies and identified the altered trace elements in AD patients. We searched the Web of Science Core Collection, PubMed, and Scopus database, and ultimately included 73 articles. A bibliometric analysis was conducted to explore the evolution of the field from an epidemiological perspective. Bibliometric data such as trace elements, biological materials, detection methods, cognitive tests, co-occurrence and co-citation statistics are all analyzed and presented in a quantitative manner. The 73 included studies analyzed 39 trace elements in total. In a further meta-analysis, standardized mean differences (SMDs) of 13 elements were calculated to evaluate their altered in AD patients, including copper, iron, zinc, selenium, manganese, lead, aluminum, cadmium, chromium, arsenic, mercury, cobalt, and manganese. We identified four trace elements-copper (serum), iron (plasma), zinc (hair), and selenium (plasma)-altered in AD patients, with SMDs of 0.37 (95% confidence interval [CI]: 0.10, 0.65), -0.68 (95% CI: -1.34, -0.02), -0.35 (95% CI: -0.62, -0.08), and -0.61 (95% CI: -0.97, -0.25), respectively. Finally, we formed a database of various trace element levels in AD patients and healthy controls. Our study can help future researchers gain a comprehensive understanding of the advancements in the field, and our results provide comprehensive population-based data for future research.

Alzheimer's disease: history, ethics and medical humanities in the context of assisted suicide

INTRODUCTION

Dementia diseases, especially Alzheimer's disease (AD), are of considerable importance in terms of social policy and health economics. Moreover, against the background of the current Karlsruhe judgement on the legalisation of assisted suicide, there are also questions to be asked about medical humanities in AD.

METHODOLOGY

Relevant literature on complementary forms of therapy and prognosis was included and discussed.

RESULTS

Creative sociotherapeutic approaches (art, music, dance) and validating psychotherapeutic approaches show promise for suitability and efficiency in the treatment of dementia, but in some cases still need to be scientifically tested. Biomarker-based early diagnosis of dementia diseases is increasingly becoming a subject of debate against the background of the Karlsruhe ruling.

DISCUSSION

Needs-oriented and resource-enhancing approaches can make a significant contribution to improving the quality of life of people with dementia. The discussion on the issue of "assisted suicide" should include questions of the dignity and value of a life with dementia.

OUTLOOK

The integrative dementia therapy model can be complemented by a religion- and spirituality-based approach. Appropriate forms of psychotherapy should be scientifically evaluated.

Dysfunction of the blood-brain barrier in Alzheimer's disease: evidence from human studies

The pathological processes leading to synapse loss, neuronal loss, brain atrophy and gliosis in Alzheimer´s disease (AD) and their relation to vascular disease and immunological changes are yet to be fully explored. Amyloid-β (Aβ) aggregation, vascular damage and altered immune response interact at the blood-brain-barrier (BBB), affecting the brain endothelium and fuelling neurodegeneration. The aim of the present systematic literature review was to critically appraise and to summarise the published evidence on the clinical correlations and pathophysiological concepts of BBB damage in AD, focusing on human data. The PubMed, Cochrane, Medline and Embase databases were searched for original research articles, systematic reviews and meta-analyses, published in English language from 01/2000 to 07/2021, using the keywords Alzheimer*, amyloid-β or β-amyloid or abeta and brain-blood barrier or BBB. This review shows that specific changes of intercellular structures, reduced expression of transendothelial carriers, induction of vasoactive mediators and activation of both astroglia and monocytes/macrophages characterise blood-brain barrier damage in human AD and AD models. BBB dysfunction on magnetic resonance imaging takes place early in the disease course in AD-specific brain regions. The toxic effects of Aβ and apolipoprotein E (ApoE) are likely to induce a non-cerebral-amyloid-angiopathy-related degeneration of endothelial cells, independently of cerebrovascular disease; however, some of the observed structural changes may just arise with age. Small vessel disease, ApoE, loss of pericytes, pro-inflammatory signalling and cerebral amyloid angiopathy enhance blood-brain-barrier damage. Novel therapeutic approaches for AD, including magnetic resonance-guided focused ultrasound, aim to open the BBB, potentially leading to an improved drainage of Aβ along perivascular channels and increased elimination from the brain. In vitro treatments with ApoE-modifying agents yielded promising effects on modulating BBB function. Reducing cardiovascular risk factors represents one of the most promising interventions for dementia prevention at present. However, further research is needed to elucidate the connection of BBB damage and tau pathology, the role of pro-inflammatory mediators in draining macromolecules and cells from the cerebral parenchyma, including their contribution to cerebral amyloid angiopathy. Improved insight into these pathomechanisms may allow to shed light on the role of Aβ deposition as a primary vs. a secondary event in the complex pathogenesis of AD.

Accelerated Approval of Aducanumab: Where Do We Stand Now?

Aducanumab was approved by the Food and Drug Administration (FDA) in June 2021 to treat Alzheimer disease (AD). Its path to approval has been highly scrutinized, with many experts arguing that the FDA's decision was premature. Accelerated approval was based on a surrogate end point, with evidence to support clinical effectiveness pending a postapproval trial by the drug company sponsor Biogen. As a result, the role of aducanumab in treating AD remains uncertain. A summary of key areas of controversy to guide informed decisions about use of this drug is provided, along with a timeline describing preapproval and postapproval events.

Association Between Antibiotic Treatment of Chlamydia pneumoniae and Reduced Risk of Alzheimer Dementia: A Nationwide Cohort Study in Taiwan

Background: Chlamydia pneumoniae (CPn) is a common community-acquired pneumonia. In the literature, CPn infection is demonstrated to exhibit an association with Alzheimer dementia (AD). We executed the present nationwide, population-based research with the goal of probing the association of CPn infection and antibiotic therapy with AD risk. Methods: We conducted a cohort study using a database extracted from Taiwan's National Health Insurance Research Database (NHIRD). All medical conditions for each enrolled individuals were categorized using the International Classification of Diseases, ninth Revision classifications. Hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between CPn pneumonia-associated hospitalizations and AD were estimated using Fine and Gray's survival analysis and adjusted for comorbidities. The effects of the antibiotics on the HRs for AD in the patients with CPn pneumonia-associated hospitalization were also analyzed. Results: Our analyses included 6,628 individuals, including 1,657 CPn-infected patients, as well as 4,971 controls matched by age, index date, and sex (1:3). In this study, patients hospitalized for CPn pneumonia exhibited a significantly higher AD risk (adjusted HR = 1.599, 95% CI = 1.284-1.971, p < 0.001). We also noted an association of macrolide use (≥15 days) and fluoroquinolone use (≥15 days) with decreased AD risk. Conclusions: We determined CPn pneumonia to be associated with a relatively high AD risk. The result in this study confirmed the findings from previous literatures, by using a large, nationwide, population-based database. Appropriate macrolide and fluoroquinolone treatment may attenuate this risk.

History of Falls, Dementia, Lower Education Levels, Mobility Limitations, and Aging Are Risk Factors for Falls among the Community-Dwelling Elderly: A Cohort Study

Background: Falling is a serious issue among elderly community dwellers, often resulting in disability. We aimed to investigate the risk factors for falls among elderly community dwellers. Methods: We recruited 232 participants from multiple community learning and care centers, who provided their information through questionnaires. They were divided into two groups, according to their falling events after a 1-year follow-up. Univariate and multivariate logistic regressions were used for statistical analysis. Results: A total of 64 participants reported a fall at the 1-year follow-up. The falling group comprised older and single people with lower education levels, higher rates of dementia, a history of falls, lower scores on the Mini-Mental State Examination, and more disability functions when compared to the non-falling group (all p < 0.05). The regression model showed that a history of falls (OR: 62.011; p < 0.0001), lower education levels (OR: 4.088; p = 0.039), mild dementia (OR: 20.729; p = 0.028), older age (OR: 1.176; p < 0.0001), walking for 300 m (OR: 4.153; p = 0.030), and running for 30 m (OR: 3.402; p = 0.015) were 1-year risk factors for falls. Conclusion: A history of falling, low education levels, aging, mild dementia, and certain mobility limitations were strong risk factors for future falling accidents in elderly Taiwanese community dwellers.

Global warming and neurological practice: systematic review

Background

Climate change, including global warming, will cause poorer global health and rising numbers of environmental refugees. As neurological disorders account for a major share of morbidity and mortality worldwide, global warming is also destined to alter neurological practice; however, to what extent and by which mechanisms is unknown. We aimed to collect information about the effects of ambient temperatures and human migration on the epidemiology and clinical manifestations of neurological disorders.

Methods

We searched PubMed and Scopus from 01/2000 to 12/2020 for human studies addressing the influence of ambient temperatures and human migration on Alzheimer’s and non-Alzheimer’s dementia, epilepsy, headache/migraine, multiple sclerosis, Parkinson’s disease, stroke, and tick-borne encephalitis (a model disease for neuroinfections). The protocol was pre-registered with PROSPERO (2020 CRD42020147543).

Results

Ninety-three studies met inclusion criteria, 84 of which reported on ambient temperatures and nine on migration. Overall, most temperature studies suggested a relationship between increasing temperatures and higher mortality and/or morbidity, whereas results were more ambiguous for migration studies. However, we were unable to identify a single adequately designed study addressing how global warming and human migration will change neurological practice. Still, extracted data indicated multiple ways by which these aspects might alter neurological morbidity and mortality soon.

Conclusion

Significant heterogeneity exists across studies with respect to methodology, outcome measures, confounders and study design, including lack of data from low-income countries, but the evidence so far suggests that climate change will affect the practice of all major neurological disorders in the near future. Adequately designed studies to address this issue are urgently needed, requiring concerted efforts from the entire neurological community.

Impact of the Apolipoprotein E ε4 Allele on the Relationship Between Healthy Lifestyle and Cognitive Decline: A Population-Based Study

Adherence to a healthy lifestyle-characterized by abstaining from smoking, being physically and cognitively active, having a high-quality diet, and limiting alcohol use-is associated with slower cognitive decline in older adults, but whether this relationship extends to persons with a genetic predisposition (e.g., carriers of the ε4 allele of the apolipoprotein E gene (APOE*E4)) remains uncertain. Using data from a population-based study, the Chicago Health and Aging Project (Chicago, Illinois), we followed 3,886 individuals who underwent regular clinical and cognitive assessments from 1993 to 2012. Of 3,886 older adults, 1,269 (32.7%) were APOE*E4 carriers. Compared with noncarriers, APOE*E4 carriers had faster cognitive decline (β = -0.027 units/year, 95% confidence interval (CI): -0.032, -0.023). In contrast, persons with 2-3 and 4-5 healthy lifestyle factors had slower cognitive decline (β = 0.008 units/year (95% CI: 0.002, 0.014) and β = 0.019 units/year (95% CI: 0.011, 0.026), respectively) compared with those with 0-1 factor. In analyses stratified by APOE*E4 status, adherence to a healthy lifestyle (e.g., 4-5 factors vs. 0-1 factors) was associated with a slower rate of cognitive decline in both APOE*E4 carriers (β = 0.029, 95% CI: 0.013, 0.045) and noncarriers (β = 0.013, 95% CI: 0.005, 0.022). These results underscore the impact of a healthy lifestyle on cognition, particularly among persons with a genetic predisposition, who are more vulnerable to cognitive decline as they age.

Characteristics of Regional Cerebral Blood Flow in Alzheimer Disease and Amnestic Mild Cognitive Impairment by Single-Photon Emission Computerized Tomography: A Cross-Sectional Study

Introduction

The regional cerebral blood flow (rCBF) distribution can affect brain functioning, leading to amnestic mild cognitive impairment (aMCI) and mild Alzheimer disease (AD). This study aimed to clarify the detailed characteristics of rCBF distribution in patients with mild AD and aMCI.

Methods

This cross-sectional study from April 2015 to March 2018 included 103 older adults (mean age 78.9 years; 60% females), out of a total of 302 adults, and categorized them into 3 groups according to cognitive symptoms. The normal control (NC), aMCI, and mild AD groups included 20, 50, and 33 participants, respectively. The primary outcome was rCBF, which was compared among the 3 groups using a 2-sample t test without correction for multiple comparisons.

Results

In the aMCI group, the rCBF decreased in the bilateral parietal and left frontal association cortex and the bilateral premotor cortex (p < 0.01) but increased in the bilateral cerebellum (p < 0.01). In the mild AD group, the rCBF decreased in the bilateral parietal and occipital association cortex, the bilateral premotor cortex, the left temporal and frontal association cortex, and the left limbic lobe (p < 0.01). Conversely, the rCBF increased in some parts of the cerebellum, the bilateral frontal and temporal association cortex, the left occipital association cortex, and the right premotor cortex (p < 0.01).

Conclusion

Based on the analysis of the values obtained, it was inferred that the rCBF undergoes reduction and elevation in aMCI and AD patients.

A Systematic Review of the Association between Amyloid-β and τ Pathology with Functional Connectivity Alterations in the Alzheimer Dementia Spectrum Utilizing PET Scan and rsfMRI

The association between functional connectivity (FC) alterations with amyloid-β (Aβ) and τ protein depositions in Alzheimer dementia is a subject of debate in the current literature. Although many studies have suggested a declining FC accompanying increased Aβ and τ concentrations, some investigations have contradicted this hypothesis. Therefore, this systematic review was conducted to sum up the current literature in this regard. The PROSPERO guideline for systematic reviews was applied for development of a research protocol, and this study was initiated after getting the protocol approval. Studies were screened, and those investigating FC measured by resting-state functional MRI and Aβ and τ protein depositions using amyloid and τ positron emission tomography were included. We categorized the included studies into 3 groups methodologically, addressing the question using global connectivity analysis (examining all regions of interest across the brain based on a functional atlas), seed-based connectivity analysis, or within-networks connectivity analysis. The quality of the studies was assessed using the Newcastle-Ottawa Scale. Among 31 included studies, 14 found both positive and negative correlations depending on the brain region and stage of the investigated disease, while 7 showed an overall negative correlation, 8 indicated an overall positive correlation, and 2 found a nonsignificant association between protein deposition and FC. The investigated regions were illustrated using tables. The posterior default mode network, one of the first regions of amyloid accumulation, and the temporal lobe, the early τ deposition region, are the 2 most investigated regions where inconsistencies exist. In conclusion, our study indicates that transneuronal spreading of τ and the amyloid hypothesis can justify higher FC related to higher protein depositions when global connectivity analysis is applied. However, the discrepancies observed when investigating the brain locally could be due to the varying manifestations of the amyloid and τ overload compensatory mechanisms in the brain at different stages of the disease with hyper- and hypoconnectivity cycles that can occur repeatedly. Nevertheless, further studies investigating both amyloid and τ deposition simultaneously while considering the stage of Alzheimer dementia are required to assess the accuracy of this hypothesis.

Plasma Concentrations of Magnesium and Risk of Dementia: A General Population Study of 102 648 Individuals

BACKGROUND

Low and high concentrations of plasma magnesium are associated with increased risk of future all-cause dementia; however, the underlying reasons remain elusive. The magnesium ion is an important electrolyte serving as a cofactor in many enzymatic processes in the human organism. Magnesium affects both neuronal and vascular functions. We investigated the associations of plasma concentrations of magnesium associate with common subtypes of dementia as Alzheimer dementia and non-Alzheimer dementia, and potential pathways by which magnesium may affect risk of dementia.

METHODS

Plasma concentrations of magnesium were measured in 102 648 individuals from the Copenhagen General Population Study. Cox regression and natural effects mediation analyses evaluated associations with either Alzheimer dementia or non-Alzheimer dementia.

RESULTS

Multifactorially adjusted hazard ratios for non-Alzheimer dementia were 1.50(95% confidence interval (CI):1.21-1.87) for the lowest and 1.34(1.07-1.69) for the highest vs the fourth quintile (reference) of plasma magnesium concentrations. Diabetes, cumulated smoking, stroke, and systolic blood pressure mediated 10.4%(3.1-22.8%), 6.8%(1.2-14.0%), 1.3%(0.1-3.6%), and 1.0%(0.2-2.6%), respectively, in the lowest quintile, whereas stroke mediated 3.2%(0.4-11.9%) in the highest quintile. No associations were observed for Alzheimer dementia.

CONCLUSIONS

Low and high plasma magnesium concentrations were associated with high risk of vascular-related non-Alzheimer dementia, with the lowest risk observed at a concentration of 2.07 mg/dL (0.85 mmol/L). No association was observed for Alzheimer dementia. Mediation analysis suggested that diabetes may be in the causal pathway between low plasma magnesium concentrations and high risk of non-Alzheimer dementia, while cumulated smoking, stroke, and systolic blood pressure played minor mediating roles.

Dietary carotenoids related to risk of incident Alzheimer dementia (AD) and brain AD neuropathology: a community-based cohort of older adults

BACKGROUND

Studies have reported a protective relation to cognitive decline with long-term intake of total and individual dietary carotenoids. However, the underlying mechanisms have not yet been clearly established in humans.

OBJECTIVES

To evaluate the prospective association between intakes of total and individual carotenoids and risk of incident Alzheimer dementia (AD) and explore the underlying neuropathological basis.

METHODS

Among 927 participants from the Rush Memory and Aging Project who were free from AD at baseline and were followed up for a mean of 7 y, we estimated HRs for AD using Cox proportional hazards models by intakes of energy-adjusted carotenoids. Brain AD neuropathology was assessed in postmortem brain autopsies among 508 deceased participants. We used linear regression to assess the association of carotenoid intake with AD-related neuropathology.

RESULTS

Higher intake of total carotenoids was associated with substantially lower hazard of AD after controlling for age, sex, education, ApoE-ε4, participation in cognitively stimulating activities, and physical activity level. Comparing the top and bottom quintiles (median intake: 24.8 compared with 6.7 mg/d) of total carotenoids, the multivariate HR (95% CI) was 0.52 (0.33, 0.81), P-trend < 0.01. A similar association was observed for lutein-zeaxanthin, a weaker linear inverse association was observed for β-carotene, and a marginally significant linear inverse association was found for β-cryptoxanthin. Among the deceased participants, consumers of higher total carotenoids (top compared with bottom tertile, 18.2 compared with 8.2 mg/d) had less global AD pathology (b: -0.10; SE = 0.04; P-trend = 0.01). For individual carotenoids, lutein-zeaxanthin and lycopene were inversely associated with brain global pathology, whereas lutein-zeaxanthin showed additional inverse associations with AD diagnostic score, neuritic plaque severity, and neurofibrillary tangle density and severity.

CONCLUSIONS

Our findings support a beneficial role of total carotenoid consumption, in particular lutein/zeaxanthin, on AD incidence that may be related to the inhibition of brain β-amyloid deposition and fibril formation.

Bayesian Genome-wide TWAS Method to Leverage both cis- and trans-eQTL Information through Summary Statistics

Transcriptome-wide association studies (TWASs) have been widely used to integrate gene expression and genetic data for studying complex traits. Due to the computational burden, existing TWAS methods do not assess distant trans-expression quantitative trait loci (eQTL) that are known to explain important expression variation for most genes. We propose a Bayesian genome-wide TWAS (BGW-TWAS) method that leverages both cis- and trans-eQTL information for a TWAS. Our BGW-TWAS method is based on Bayesian variable selection regression, which not only accounts for cis- and trans-eQTL of the target gene but also enables efficient computation by using summary statistics from standard eQTL analyses. Our simulation studies illustrated that BGW-TWASs achieved higher power compared to existing TWAS methods that do not assess trans-eQTL information. We further applied BWG-TWAS to individual-level GWAS data (N = ∼3.3K), which identified significant associations between the genetically regulated gene expression (GReX) of ZC3H12B and Alzheimer dementia (AD) (p value = 5.42 × 10-13), neurofibrillary tangle density (p value = 1.89 × 10-6), and global measure of AD pathology (p value = 9.59 × 10-7). These associations for ZC3H12B were completely driven by trans-eQTL. Additionally, the GReX of KCTD12 was found to be significantly associated with β-amyloid (p value = 3.44 × 10-8) which was driven by both cis- and trans-eQTL. Four of the top driven trans-eQTL of ZC3H12B are located within APOC1, a known major risk gene of AD and blood lipids. Additionally, by applying BGW-TWAS with summary-level GWAS data of AD (N = ∼54K), we identified 13 significant genes including known GWAS risk genes HLA-DRB1 and APOC1, as well as ZC3H12B.

White Matter Hyperintensities and Cognitive Impairment in Healthy and Pathological Aging: A Quantified Brain MRI Study

BACKGROUND

Brain changes involving the white matter (WM), often an indication of cerebrovascular pathology, are frequently seen in patients with mild cognitive impairment (MCI) and Alzheimer disease (AD). Few studies have examined possible cognitive domain- or group-specific cognitive effects of WM pathology in old age, MCI, and AD.

OBJECTIVE

Our purpose was to examine the relationship between WM hyperintensities (WMH), a typical marker for WM pathology, and cognitive functioning in healthy old age and pathological aging using quantified MRI data.

METHODS

We utilized multidomain neuropsychological data and quantified MRI data from a sample of 42 cognitively healthy older adults and 44 patients with MCI/AD (total n = 86).

RESULTS

After controlling for age and education, WMH in the temporal and parieto-occipital lobes was associated with impairments in processing speed and parieto-occipital pathology with verbal memory impairment in the whole sample. Additionally, temporal WMH was associated with impaired processing speed in the patient group specifically.

CONCLUSIONS

WM pathology is strongly associated with impaired processing speed, and our results indicate that these impairments arise from WMH in the temporal and parieto-occipital regions. In MCI and AD patients with temporal WMH, processing speed impairments are especially prominent. The results of this study increase our knowledge of cognitive repercussions stemming from temporal and/or parieto-occipital WM pathology in healthy and pathological aging.

Alix and Syntenin-1 direct amyloid precursor protein trafficking into extracellular vesicles

BACKGROUND

Endosomal trafficking and amyloidogenic cleavage of amyloid precursor protein (APP) is believed to play a role in the neurodegeneration observed in Alzheimer's disease (AD). Recent evidence has suggested that packaging and secretion of APP and its amyloidogenic cleaved products into small extracellular vesicles (EVs) may facilitate uptake of these neurotoxic factors during disease progression. However, the molecular mechanisms underlying trafficking of APP into EVs are poorly understood.

RESULTS

In this study, the mechanism and impact of APP trafficking into extracellular vesicles (EVs) were assessed by a series of inducible gene knockdowns. We demonstrate that vesicle-associated proteins Alix and Syntenin-1 are essential for proper subcellular localization and efficient EV secretion of APP via an endosomal sorting complexes required for transport (ESCRT)-independent pathway. The neurotoxic C-terminal fragment (CTFβ) of APP is similarly secreted in association with small vesicles. These mechanisms are conserved in terminally differentiated neuron-like cells. Furthermore, knockdown of Alix and Syntenin-1 alters the subcellular localization of APP, sequestering the precursor protein to endoplasmic reticulum and endolysosomal compartments, respectively. Finally, transfer of small EVs containing mutant APP confers an increase in reactive oxygen species production and neurotoxicity to human induced pluripotent stem cell-derived cortical neurons and naïve primary neurons, an effect that is ameliorated by Alix and Syntenin-1 depletion.

CONCLUSIONS

Altogether these findings elucidate a novel mechanism for understanding the intracellular trafficking of APP and CTFβ into secreted extracellular vesicles, and the resultant potential impact on neurotoxicity in the context of Alzheimer's disease amyloidopathy.

A Systematic Review of Neuropsychological Tests for the Assessment of Dementia in Non-Western, Low-Educated or Illiterate Populations

OBJECTIVE

Neuropsychological tests are important instruments to determine a cognitive profile, giving insight into the etiology of dementia; however, these tests cannot readily be used in culturally diverse, low-educated populations, due to their dependence upon (Western) culture, education, and literacy. In this review we aim to give an overview of studies investigating domain-specific cognitive tests used to assess dementia in non-Western, low-educated populations. The second aim was to examine the quality of these studies and of the adaptations for culturally, linguistically, and educationally diverse populations.

METHOD

A systematic review was performed using six databases, without restrictions on the year or language of publication.

RESULTS

Forty-four studies were included, stemming mainly from Brazil, Hong Kong, Korea, and considering Hispanics/Latinos residing in the USA. Most studies focused on Alzheimer's disease (n = 17) or unspecified dementia (n = 16). Memory (n = 18) was studied most often, using 14 different tests. The traditional Western tests in the domains of attention (n = 8) and construction (n = 15), were unsuitable for low-educated patients. There was little variety in instruments measuring executive functioning (two tests, n = 13), and language (n = 12, of which 10 were naming tests). Many studies did not report a thorough adaptation procedure (n = 39) or blinding procedures (n = 29).

CONCLUSIONS

Various formats of memory tests seem suitable for low-educated, non-Western populations. Promising tasks in other cognitive domains are the Stick Design Test, Five Digit Test, and verbal fluency test. Further research is needed regarding cross-cultural instruments measuring executive functioning and language in low-educated people.

Loneliness and Burden Perceived by Family Caregivers of Patients With Alzheimer Disease

BACKGROUND

The present study aimed at investigating loneliness and burden experienced by family members caring for relatives diagnosed with Alzheimer disease.

METHODS

Participants were 40 caregivers of inpatients with Alzheimer disease. Correlation and multiple regression analyses were conducted to investigate whether caregivers' loneliness (uni- and multidimensional) and burden are associated with and predicted by (1) specific caregiver characteristics and/or (2) patients' dementia severity and neuropsychiatric symptoms.

RESULTS

Loneliness was significantly correlated with caregivers' sex, age, and living circumstances, while burden was significantly correlated with caregivers' education solely. Regression analyses revealed that caregivers' sex and living circumstances contributed significantly to variance explanation of loneliness (but not burden), while the additional consideration of patient variables did not improve model fit.

CONCLUSIONS

Loneliness reported by caregivers of relatives diagnosed with dementia is significantly modulated by caregiver (but not patient) characteristics. Notably, both uni- and multidimensional loneliness scales seem to be sensitive diagnostic tools.

Escitalopram for agitation in Alzheimer's disease (S-CitAD): Methods and design of an investigator-initiated, randomized, controlled, multicenter clinical trial

INTRODUCTION

Alzheimer's disease (AD) is a disabling, common cause of dementia, and agitation is one of the most common and distressing symptoms for patients with AD. Escitalopram for agitation in Alzheimer's disease (S-CitAD) tests a novel, clinically derived therapeutic approach to treat agitation in patients with AD.

METHODS

S-CitAD is a NIH-funded, investigator-initiated, randomized, multicenter clinical trial. Participants receive a structured psychosocial intervention (PSI) as standard of care. Participants without sufficient response to PSI are randomized to receive 15 mg escitalopram/day or a matching placebo in addition to PSI. Primary outcome is the Modified Alzheimer's Disease Cooperative Study - Clinical Global Impression of Change (mADCS-CGIC).

DISCUSSION

S-CitAD will provide information about a practical, immediately available approach to treating agitation in patients with AD. S-CitAD may become a model of how to evaluate and predict treatment response in patients with AD and agitation as a neuropsychiatric symptom (ClinicalTrials.gov Identifier: NCT03108846).

Multimodal 18F-AV-1451 and MRI Findings in Nonfluent Variant of Primary Progressive Aphasia: Possible Insights on Nodal Propagation of Tau Protein Across the Syntactic Network

Although abnormally folded tau protein has been found to self-propagate from neuron to connected neuron, similar propagation through human brain networks has not been fully documented. We studied tau propagation in the left hemispheric syntactic network, which comprises an anterior frontal node and a posterior temporal node connected by the white matter of the left arcuate fasciculus. This network is affected in the nonfluent variant of primary progressive aphasia, a neurodegenerative disorder with tau accumulation. Methods: Eight patients with the nonfluent variant of primary progressive aphasia (age, 67.0 ± 7.4 y; 4 women) and 8 healthy controls (age, 69.6 ± 7.0 y; 4 women) were scanned with ¹⁸F-AV-1451 tau PET to determine tau deposition in the brain and with MRI to determine the fractional anisotropy of the arcuate fasciculus. Normal syntactic network characteristics were confirmed with structural MRI diffusion imaging in our healthy controls and with blood oxygenation level-dependent functional imaging in 35 healthy participants from the Alzheimer Disease Neuroimaging Initiative database. Results: Language scores in patients indicated dysfunction of the anterior node. ¹⁸F-AV-1451 deposition was greatest in the 2 nodes of the syntactic network. The left arcuate fasciculus had decreased fractional anisotropy, particularly near the anterior node. Normal MRI structural connectivity from an area similar to the one containing tau in the anterior frontal node projected to an area similar to the one containing tau in the patients in the posterior temporal node. Conclusion: Tau accumulation likely started in the more affected anterior node and, at the disease stage at which we studied these patients, appeared as well in the brain region (in the temporal lobe) spatially separate from but most connected with it. The arcuate fasciculus, connecting both of them, was most severely affected anteriorly, as would correspond to a loss of axons from the anterior node. These findings are suggestive of tau propagation from node to connected node in a natural human brain network and support the idea that neurons that wire together die together.

Attention Measures of Accuracy, Variability, and Fatigue Detect Early Response to Donepezil in Alzheimer's Disease: A Randomized, Double-blind, Placebo-Controlled Pilot Trial

OBJECTIVE

Donepezil is widely used to treat Alzheimer's disease (AD), but detecting early response remains challenging for clinicians. Acetylcholine is known to directly modulate attention, particularly under high cognitive conditions, but no studies to date test whether measures of attention under high load can detect early effects of donepezil. We hypothesized that load-dependent attention tasks are sensitive to short-term treatment effects of donepezil, while global and other domain-specific cognitive measures are not.

METHOD

This longitudinal, randomized, double-blind, placebo-controlled pilot trial (ClinicalTrials.gov Identifier: NCT03073876) evaluated 23 participants newly diagnosed with AD initiating de novo donepezil treatment (5 mg). After baseline assessment, participants were randomized into Drug (n = 12) or Placebo (n = 11) groups, and retested after approximately 6 weeks. Cognitive assessment included: (a) attention tasks (Foreperiod Effect, Attentional Blink, and Covert Orienting tasks) measuring processing speed, top-down accuracy, orienting, intra-individual variability, and fatigue; (b) global measures (Alzheimer's Disease Assessment Scale-Cognitive Subscale, Mini-Mental Status Examination, Dementia Rating Scale); and (c) domain-specific measures (memory, language, visuospatial, and executive function).

RESULTS

The Drug but not the Placebo group showed benefits of treatment at high-load measures by preserving top-down accuracy, improving intra-individual variability, and averting fatigue. In contrast, other global or cognitive domain-specific measures could not detect treatment effects over the same treatment interval.

CONCLUSIONS

The pilot-study suggests that attention measures targeting accuracy, variability, and fatigue under high-load conditions could be sensitive to short-term cholinergic treatment. Given the central role of acetylcholine in attentional function, load-dependent attentional measures may be valuable cognitive markers of early treatment response.

Principal Components Analysis of Brain Metabolism Predicts Development of Alzheimer Dementia

The value of ¹⁸F-FDG PET for predicting conversion from mild cognitive impairment (MCI) to Alzheimer dementia (AD) is currently under debate. We used a principal components analysis (PCA) to identify a metabolic AD conversion-related pattern (ADCRP) and investigated the prognostic value of the resulting pattern expression score (PES). Methods: ¹⁸F-FDG PET scans of 544 MCI patients were obtained from the Alzheimer Disease Neuroimaging Initiative database and analyzed. We implemented voxel-based PCA and standard Statistical Parametric Mapping analysis (as a reference) to disclose cerebral metabolic patterns associated with conversion from MCI to AD. By Cox proportional hazards regression, we examined the prognostic value of candidate predictors. Also, we constructed prognostic models with clinical, imaging, and clinical and imaging variables in combination. Results: PCA revealed an ADCRP that involved regions with relative decreases in metabolism (temporoparietal, frontal, posterior cingulate, and precuneus cortices) and relative increases in metabolism (sensorimotor and occipital cortices, cerebellum, and left putamen). Among the predictor variables age, sex, Functional Activities Questionnaire, Mini-Mental State Examination, apolipoprotein E, PES, and normalized ¹⁸F-FDG uptake (regions with significant hypo- and hypermetabolism in patients with conversion vs. those without conversion), PES was the best independent predictor of conversion (hazard ratio, 1.77, per z score increase; 95% CI, 1.24-2.52; P < 0.001). Moreover, adding PES to the model including the clinical variables significantly increased its prognostic value. Conclusion: The ADCRP expression score was a valid predictor of conversion. A combination of clinical variables and PES yielded a higher accuracy than each single tool in predicting conversion from MCI to AD, underlining the incremental utility of ¹⁸F-FDG PET.

Depression and Risk of Alzheimer Dementia: A Longitudinal Analysis to Determine Predictors of Increased Risk among Older Adults with Depression

OBJECTIVE

Older adults with depression are at increased risk of Alzheimer dementia, but predictors of increased risk remain incompletely understood. We aim to identify characteristics of older adults with depression most at risk of progressing to Alzheimer dementia. Identification of high-risk subgroups could facilitate future interventional strategies to reduce risk of Alzheimer dementia in older adults with depression.

METHODS

Using data from the National Alzheimer's Coordinating Center, 1,965 participants with clinically defined depression and mild cognitive impairment at baseline were followed until development of Alzheimer dementia or loss to follow-up.

RESULTS

Seven hundred and eighty (39.7%) developed Alzheimer dementia over a median follow-up duration of 27 months. In survival analyses, age (hazard ratio [HR] 1.04, 95% 1.03-1.05), baseline Mini-Mental State Exam (HR 0.85, 95% confidence interval 0.83-0.87), amnestic subtype of mild cognitive impairment (HR 1.66, 95% 1.30-2.12), presence of APOE4 allele (HR 1.99, 1.69-2.36), and presence of active depression within the last two years (HR 1.44, 95% confidence interval 1.16-1.79) were all independently associated with increased risk of Alzheimer dementia. Six hundred and fifty-six (41.7%) participants with mild cognitive impairment and active depression within the last two years developed Alzheimer dementia compared to 120 (31.6%) of those with a more remote history of depression.

CONCLUSION

Older adults with depression and mild cognitive impairment demonstrated a high rate of progression to Alzheimer dementia over a relatively short duration of follow-up. Individuals with a combination of mild cognitive impairment and recently active depression are a particularly high-risk subgroup.

We are what we eat: How food is represented in our mind/brain

Despite the essential role of food in our lives, we have little understanding of the way our knowledge about food is organized in the brain. At birth, human infants exhibit very few food preferences, and do not yet know much about what is edible and what is not. A multisensory learning development will eventually turn young infants into omnivore adults, for whom deciding what to eat becomes an effortful task. Recognizing food constitutes an essential step in this decisional process. In this paper we examine how concepts about food are represented in the human brain. More specifically, we first analyze how brain-damaged patients recognize natural and manufactured food, and then examine these patterns in the light of the sensory-functional hypothesis and the domain-specific hypothesis. Secondly, we discuss how concepts of food are represented depending on whether we embrace the embodied view or the disembodied view. We conclude that research on food recognition and on the organization of knowledge about food must also take into account some aspects specific to food category, the relevance of which has not been sufficiently recognized and investigated to date.

Objective features of subjective cognitive decline in a United States national database

INTRODUCTION

Functional and cognitive features of subjective cognitive decline (SCD) were identified in a longitudinal database from the National Alzheimer's Coordinating Center.

METHODS

Cognitively normal older adults with (SCD+) and without (SCD-) self-reported memory complaints (N = 3915) were compared on (1) baseline Functional Assessment Questionnaire ratings, (2) baseline scores and longitudinal rate of change estimates from nine neuropsychological tests, and (3) final clinical diagnoses.

RESULTS

SCD+ had higher baseline ratings of functional impairment, reduced episodic memory practice effects and poorer performance on neuropsychological tests of psychomotor speed and language, and higher frequencies of mild cognitive impairment and dementia diagnoses at the end of follow-up compared with the SCD-group.

DISCUSSION

Subtle clinical features of SCD identified in this large cohort are difficult to detect at the individual level. More sensitive tests are needed to identify those with SCD who are vulnerable to cognitive decline and dementia.

[Prevention of Alzheimer's dementia in Germany : A projection of the possible potential of reducing selected risk factors]

BACKGROUND

Current international projections suggest that reducing the prevalence of seven well-established risk factors, midlife hypertension and obesity, diabetes mellitus, depression, physical inactivity, smoking and low educational attainment, may also substantially reduce the prevalence of Alzheimer's dementia (AD).

OBJECTIVE

Following the procedures of the international projections, in this study we aimed to provide projections of a corresponding potential for prevention specific for Germany.

METHODS

For each risk factor separately and combined (with adjustment for the association between the risk factors) we calculated (1) the population attributable risk (PAR) for AD, (2) the corresponding total number of attributable AD cases and (3) the potential number of current AD cases that may have been prevented by a 10 %, 25 % and 50 % lower prevalence of the risk factors.

RESULTS

According to the population projections 30.5 % of the current AD cases in Germany could be attributable to the risk factors considered (305,000 AD cases in total). The highest estimated impact on AD prevalence was found for physical inactivity (PAR = 21.7 %, 217,000 attributable cases) and smoking (PAR = 14.9 %, 149,000 cases). A 10-50 % reduction in the prevalence of all seven risk factors could have potentially prevented 23,000-130,000 of the current AD cases in Germany.

CONCLUSION

The identified possible substantial potential for reducing AD prevalence should act as a strong additional incentive to reduce the seven risk factors in Germany.

Next-generation sequencing reveals substantial genetic contribution to dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is the second most common neurodegenerative dementia after Alzheimer's disease. Although an increasing number of genetic factors have been connected to this debilitating condition, the proportion of cases that can be attributed to distinct genetic defects is unknown. To provide a comprehensive analysis of the frequency and spectrum of pathogenic missense mutations and coding risk variants in nine genes previously implicated in DLB, we performed exome sequencing in 111 pathologically confirmed DLB patients. All patients were Caucasian individuals from North America. Allele frequencies of identified missense mutations were compared to 222 control exomes. Remarkably, ~25% of cases were found to carry a pathogenic mutation or risk variant in APP, GBA or PSEN1, highlighting that genetic defects play a central role in the pathogenesis of this common neurodegenerative disorder. In total, 13% of our cohort carried a pathogenic mutation in GBA, 10% of cases carried a risk variant or mutation in PSEN1, and 2% were found to carry an APP mutation. The APOE ε4 risk allele was significantly overrepresented in DLB patients (p-value <0.001). Our results conclusively show that mutations in GBA, PSEN1, and APP are common in DLB and consideration should be given to offer genetic testing to patients diagnosed with Lewy body dementia.

The incidence of post-mortem neurodegenerative and cerebrovascular pathology in mixed dementia

BACKGROUND

The clinical picture of dementia in most aged patients is due to a combination of different neurodegenerative processes and frequently associated to cerebrovascular lesions. They are called mixed dementia (MixD) cases, to be differentiated from those with pure vascular dementia (VaD) and those with Alzheimer's dementia (AD). The present study compares the frequency of different associated lesions in these disease groups.

MATERIALS AND METHODS

Out of a series of 252 autopsied patients 36 with MixD, 20 with VaD and 64 with AD disease were compared concerning the frequency of the associated lesions. Small cerebrovascular lesions were evaluated on a large coronal section of a cerebral hemisphere. Mean values of frequency and severity were compared between the 3 groups.

RESULTS

Of the 120 examined brains 30% were classified as MixD, 17% as VaD and 53% as AD. In 20% of the AD patients Lewy body pathology (LBP) was observed with a low incidence of cerebrovascular lesions, except for cerebral amyloid angiopathy (CAA). The MixD patients had more severe CAA and were significantly older than those with VaD and AD. Lacunar infarcts, on the other hand, were significantly more frequent in the VaD patients.

DISCUSSION

The most responsible vascular lesions in MixD and VaD are different. There is an inverse correlation between the presence of LBP and vascular pathology. MixD has to be considered as the end stage of AD.

Morphologic and neuropsychological patterns in patients suffering from Alzheimer's disease

INTRODUCTION

We conducted a retrospective study to identify morphological subgroups of patients referred for AD or aMCI and to seek for differences across neuropsychological performances.

METHODS

One hundred forty-five patients (mean age = 76.01, 88 women and 57 men) referred for AD, either at the stage of dementia or aMCI, were examined using structural MRI. Five observers reviewed blindly twice all examinations. We rated microangiopathy, hippocampal, parietal atrophies, including a gradient of fronto-parietal atrophy (GFPA). A multiple component analysis (MCA) followed by a hierarchical ascending classification was conducted to identify morphologically distinct subgroups. Among these, 76 patients completed all the neuropsychological tests. Univariate and multivariate analyses were further conducted on these data across morphological subgroups. The institutional review board approved the research protocol.

RESULTS

Inter- and intra-raters' agreements were excellent and very good for microangiopathy and hippocampal atrophy ratings. They were higher for GFPA than for the parietal atrophy scale. MCA without priors identified three groups: group 1 was characterized by no/discrete microangiopathy, severe hippocampal, and predominant parietal atrophy; group 2 had significant microangiopathy, severe hippocampal atrophy, and no predominant parietal atrophy; group 3 had a mild hippocampal atrophy and parietal atrophies. In group 1, working memory profile was less impaired than in group 2 (p = 0.01). Neuropsychological performances of group 3 were higher in most domains.

CONCLUSION

Combined characterization of microangiopathy, hippocampal, parietal, and GFPA allows identifying morphological subgroups among patients referred for AD and at risk. These groups have some neuropsychological differences, suggesting different pathophysiological mechanisms or co-existing conditions.

Chronic Depressive Symptomatology in Mild Cognitive Impairment Is Associated with Frontal Atrophy Rate which Hastens Conversion to Alzheimer Dementia

OBJECTIVE

Investigate the association of chronic depressive symptomatology (chrDS) with cortical atrophy rates and conversion to Alzheimer dementia (AD) over 3 years in mild cognitive impairment (MCI).

METHODS

In a multicenter, clinic-based study, MCI elderly participants were selected from the Alzheimer's Disease Neuroimaging Initiative repository, based on availability of both serial structural magnetic resonance imaging and chrDS endorsed on three depression-related items from the Neuropsychiatric Inventory Questionnaire (chrDS N = 32 or no depressive symptoms N = 62) throughout follow-up. Clinical and laboratory investigations were performed every 6 months during the first 2 years and yearly thereafter (median follow-up: 3 years; interquartile range: 1.5-4.0 years). Cortical atrophy rates in 16 predefined frontotemporoparietal regions affected in major depression and AD and the rate of incident AD at follow-up.

RESULTS

ChrDS in a single domain amnestic MCI sample were associated with accelerated cortical atrophy in the frontal lobe and anterior cingulate but not with atrophy rates in temporomedial or other AD-affected regions. During follow-up, 38 participants (42.7%) developed AD. Participants with chrDS had 60% shorter conversion time to AD than those without depressive symptoms. This association remained significant in survival models adjusted for temporomedial atrophy rates and showed the same trend in models adjusted for frontal cortical atrophy rate, which all increased the risk of AD.

CONCLUSION

Our results suggest that chrDS associated with progressive atrophy of frontal regions may represent an additional risk factor for conversion to dementia in MCI as opposite to representing typical prodromal AD symptomatology.

Drug and Exercise Treatment of Alzheimer Disease and Mild Cognitive Impairment: A Systematic Review and Meta-Analysis of Effects on Cognition in Randomized Controlled Trials

OBJECTIVE

Demographic changes are increasing the pressure to improve therapeutic strategies against cognitive decline in Alzheimer disease (AD) and mild cognitive impairment (MCI). Besides drug treatment, physical activity seems to be a promising intervention target as epidemiological and clinical studies suggest beneficial effects of exercise training on cognition. Using comparable inclusion and exclusion criteria, we analyzed the efficacy of drug therapy (cholinesterase inhibitors, memantine, and Ginkgo biloba) and exercise interventions for improving cognition in AD and MCI populations.

METHODS

We searched The Cochrane Library, EBSCO, OVID, Web of Science, and U.S Food and Drug Administration data from inception through October 30, 2013. Randomized controlled trials in which at least one treatment arm consisted of an exercise or a pharmacological intervention for AD or MCI patients, and which had either a non-exposed control condition or a control condition that received another intervention. Treatment discontinuation rates and Standardized Mean Change score using Raw score standardization (SMCR) of cognitive performance were calculated.

RESULTS

Discontinuation rates varied substantially and ranged between 0% and 49% with a median of 18%. Significantly increased discontinuation rates were found for galantamine and rivastigmine as compared to placebo in AD studies. Drug treatments resulted in a small pooled effect on cognition (SMCR: 0.23, 95% CI: 0.20 to 0.25) in AD studies (N = 45, 18,434 patients) and no effect in any of the MCI studies (N = 5, 3,693 patients; SMCR: 0.03, 95% CI: 0.00 to 0.005). Exercise interventions had a moderate to strong pooled effect size (SMCR: 0.83, 95% CI: 0.59 to 1.07) in AD studies (N = 4, 119 patients), and a small effect size (SMCR: 0.20, 95% CI: 0.11 to 0.28) in MCI (N = 6, 443 patients).

CONCLUSIONS

Drug treatments have a small but significant impact on cognitive functioning in AD and exercise has the potential to improve cognition in AD and MCI. Head-to-head trials with sufficient statistical power are necessary to directly compare efficacy, safety, and acceptability. Combining these two approaches might further increase the efficacy of each individual intervention.

IDENTIFIER

PROSPERO (2013:CRD42013003910).

Rare Variants in PLD3 Do Not Affect Risk for Early-Onset Alzheimer Disease in a European Consortium Cohort

Rare variants in the phospholipase D3 gene (PLD3) were associated with increased risk for late‐onset Alzheimer disease (LOAD). We identified a missense mutation in PLD3 in whole‐genome sequence data of a patient with autopsy confirmed Alzheimer disease (AD) and onset age of 50 years. Subsequently, we sequenced PLD3 in a Belgian early‐onset Alzheimer disease (EOAD) patient (N = 261) and control (N = 319) cohort, as well as in European EOAD patients (N = 946) and control individuals (N = 1,209) ascertained in different European countries. Overall, we identified 22 rare variants with a minor allele frequency <1%, 20 missense and two splicing mutations. Burden analysis did not provide significant evidence for an enrichment of rare PLD3 variants in EOAD patients in any of the patient/control cohorts. Also, meta‐analysis of the PLD3 data, including a published dataset of a German EOAD cohort, was not significant (P = 0.43; OR = 1.53, 95% CI 0.60–3.31). Consequently, our data do not support a role for PLD3 rare variants in the genetic etiology of EOAD in European EOAD patients. Our data corroborate the negative replication data obtained in LOAD studies and therefore a genetic role of PLD3 in AD remains to be demonstrated.

Personal memory function in mild cognitive impairment and subjective memory complaints: results from the Australian Imaging, Biomarkers, and Lifestyle (AIBL) Study of Ageing

BACKGROUND

Autobiographical memory (ABM) refers to the recollection of individual experiences, while personal semantic memory (PSM) refers to personally relevant, but shared, facts. Mild cognitive impairment (MCI) is routinely diagnosed with the aid of neuropsychological tests, which do not tap the ABM and PSM domains.

OBJECTIVE

We aimed to characterize the nature of ABM and PSM retrieval in cognitively healthy (HC) memory complainers, non-memory complainers, and MCI participants, and to investigate the relationship between neuropsychological tests and personal memory.

METHODS

Gender- and education-matched participants (HC = 80 and MCI = 43) completed the Episodic ABM Interview (EAMI) and a battery of neuropsychological tests.

RESULTS

ABM and PSM did not differ between complainers and non-complainers, but were poorer in MCI participants, after accounting for age and depressive symptomatology. There were significant associations between personal memory and objective memory measures were found in MCI participants, but standard cognitive measures were more sensitive to MCI.

CONCLUSION

Personal memory was compromised in MCI, reflected by lower scores on the EAMI. Memory complaining, assessed by current approaches, did not have an impact on personal memory. Standard subjective questionnaires might not reflect the sorts of concerns that bring individuals to clinical attention. Understanding personal memory function in the elderly may aid in the development of a more sensitive measure of subjective memory concerns.

The role of nutrient-based epigenetic changes in buffering against stress, aging, and Alzheimer's disease

Converging evidence identifies stress-related disorders as putative risk factors for Alzheimer Disease (AD). This article reviews evidence on the complex interplay of stress, aging, and genes-epigenetics interactions. The recent classification of AD into preclinical, mild cognitive impairment, and AD offers a window for intervention to prevent, delay, or modify the course of AD. Evidence in support of the cognitive effects of epigenetics-diet, and nutraceuticals is reviewed. A proactive epigenetics diet and nutraceuticals program holds promise as potential buffer against the negative impact of aging and stress responses on cognition, and can optimize vascular, metabolic, and brain health in the community.

Management of Behavioral and Psychological Symptoms of Dementia

Symptoms of disturbed perception, thought content, mood, or behavior that frequently occur in patients with dementia are defined as the term "Behavioral and Psychological Symptoms of Dementia (BPSD)." The behavioral symptoms of dementia include physical/verbal aggression, agitation, disinhibition, restlessness, wandering, culturally inappropriate behaviors, sexual disinhibition, and hoarding, and the psychological symptoms of dementia are anxiety, depressive mood, hallucinations and delusions, apathy, and misidentification syndrome. With the cognitive decline in Alzheimer's Dementia (AD), the frequency of neuropsychiatric symptoms increases. Apathy, depression, irritability, agitation, and anxiety are the most frequently detected neuropsychiatric symptoms of AD. In the mild stage of AD, affective symptoms are more likely to occur; agitated and psychotic behaviors are frequent in patients with moderately impaired cognitive function. When neuropsychiatric symptoms are first detected, medical conditions, such as delirium, infection, dehydration, diarrhea, and drug interactions, must be ruled out. The treatment of mild BPSD must be started with psychosocial approaches, such as behavioral management, caregiver education, and physical activity. Medications are indicated for BPSD symptoms that are refractory to non-pharmacological interventions or severe or jeopardizing the safety of a patient or others, often in conjunction with non-pharmacological interventions.

N-acetyl-aspartate (NAA) as a correlate of pharmacological treatment in psychiatric disorders: a systematic review

The amino-acid N-acetyl-aspartate (NAA) is located in neurons and the concentration of NAA correlates with neuronal mitochondrial function. The signal of NAA, as measured with proton magnetic resonance spectroscopy (1H-MRS), is considered to reflect both, neuronal density and integrity of neuronal mitochondria. A reduction of the NAA concentrations has been found in several psychiatric disorders. Newer studies report reversal of decreased NAA concentration with treatment. The objective of this review is to summarize the literature on NAA changes in association with psychopharmacological treatment in psychiatric disorders (affective disorders, obsessive-compulsive disorder, schizophrenia and dementia). The majority of studies identified increased NAA concentrations in response to treatment, while a smaller number of studies did not find this effect. The NAA increase seems to be neither specific for a certain disorder nor for a specific intervention. This suggests that the reduction of NAA may represent an altered functional (metabolic) state of neurons common to different psychiatric disorders and the increase after treatment to indicate functional restoration as one general effect of interventions.

Ontology driven decision support for the diagnosis of mild cognitive impairment

In recent years, mild cognitive impairment (MCI) has attracted significant attention as an indicator of high risk for Alzheimer's disease (AD), and the diagnosis of MCI can alert patient to carry out appropriate strategies to prevent AD. To avoid subjectivity in diagnosis, we propose an ontology driven decision support method which is an automated procedure for diagnosing MCI through magnetic resonance imaging (MRI). In this approach, we encode specialized MRI knowledge into an ontology and construct a rule set using machine learning algorithms. Then we apply these two parts in conjunction with reasoning engine to automatically distinguish MCI patients from normal controls (NC). The rule set is trained by MRI data of 187 MCI patients and 177 normal controls selected from Alzheimer's Disease Neuroimaging Initiative (ADNI) using C4.5 algorithm. By using a 10-fold cross validation, we prove that the performance of C4.5 with 80.2% sensitivity is better than other algorithms, such as support vector machine (SVM), Bayesian network (BN) and back propagation (BP) neural networks, and C4.5 is suitable for the construction of reasoning rules. Meanwhile, the evaluation results suggest that our approach would be useful to assist physicians efficiently in real clinical diagnosis for the disease of MCI.

Translation, cross-cultural adaptation and applicability of the Brazilian version of the Frontotemporal Dementia Rating Scale (FTD-FRS)

BACKGROUND

Staging scales for dementia have been devised for grading Alzheimer's disease (AD) but do not include the specific symptoms of frontotemporal lobar degeneration (FTLD).

OBJECTIVE

To translate and adapt the Frontotemporal Dementia Rating Scale (FTD-FRS) to Brazilian Portuguese.

METHODS

The cross-cultural adaptation process consisted of the following steps: translation, back-translation (prepared by independent translators), discussion with specialists, and development of a final version after minor adjustments. A pilot application was carried out with 12 patients diagnosed with bvFTD and 11 with AD, matched for disease severity (CDR=1.0). The evaluation protocol included: Addenbrooke's Cognitive Examination-Revised (ACE-R), Mini-Mental State Examination (MMSE), Executive Interview (EXIT-25), Neuropsychiatric Inventory (NPI), Frontotemporal Dementia Rating Scale (FTD-FRS) and Clinical Dementia Rating scale (CDR).

RESULTS

The Brazilian version of the FTD-FRS seemed appropriate for use in this country. Preliminary results revealed greater levels of disability in bvFTD than in AD patients (bvFTD: 25% mild, 50% moderate and 25% severe; AD: 36.36% mild, 63.64% moderate). It appears that the CDR underrates disease severity in bvFTD since a relevant proportion of patients rated as having mild dementia (CDR=1.0) in fact had moderate or severe levels of disability according to the FTD-FRS.

CONCLUSION

The Brazilian version of the FTD-FRS seems suitable to aid staging and determining disease progression.

The differential impact of unique behavioral and psychological symptoms for the dementia caregiver: how and why do patients' individual symptom clusters impact caregiver depressive symptoms?

OBJECTIVE

The behavioral and psychological symptoms associated with dementia (BPSD) are highly burdensome to caregivers. While BPSD consist of a wide variety of patient behaviors including depression, physical aggression, and paranoid delusions, it remains unclear whether specific symptoms have a differential impact on caregivers. The aims of this study were 1) to assess how individual BPSD, categorized based on how they may affect caregivers, impact depressive symptoms for dementia patient caregivers and 2) to test the pathways by which BPSD clusters impact caregiver depressive symptoms.

DESIGN

Cross-sectional analysis of data from a longitudinal study of patients with Alzheimer disease and dementia with Lewy bodies.

SETTING

Multiple U.S. dementia clinics.

PARTICIPANTS

One hundred sixty patient-caregiver dyads.

METHODS

Using multivariate generalized estimating equation logistic models, we analyzed the relationship between four BPSD clusters (patient depressive symptoms, accusatory/aggressive behaviors, nonthreatening psychotic symptoms, and difficult to manage behaviors) and caregiver depressive symptoms and assessed mediators of these relationships.

RESULTS

Only the presence of patient depressive symptoms was associated with caregiver depression (odds ratio: 1.55; 95% confidence interval: 1.14-2.1). This relationship was mediated by caregiver report of both the symptom's impact on the patient and perceived burden to caregivers.

CONCLUSION

Patient depressive symptoms may be the most important driver of the relationship between BPSD and caregiver depression. Research in this field should further test the effects of individual BPSD and also consider how symptoms may negatively impact caregivers by increasing burden and evoking empathy for the patient.

Aphasia with left occipitotemporal hypometabolism: a novel presentation of posterior cortical atrophy?

Alzheimer's disease is a common neurodegenerative disease often characterized by initial episodic memory loss. Atypical focal cortical presentations have been described, including the logopenic variant of primary progressive aphasia (lvPPA) which presents with language impairment, and posterior cortical atrophy (PCA) which presents with prominent visuospatial deficits. Both lvPPA and PCA are characterized by specific patterns of hypometabolism: left temporoparietal in lvPPA and bilateral parietoccipital in PCA. However, not every patient fits neatly into these categories. We retrospectively identified two patients with progressive aphasia and visuospatial deficits from a speech and language based disorders study. The patients were further characterized by MRI, fluorodeoxyglucose F18 and Pittsburgh Compound B (PiB) positron emission tomography. Two women, aged 62 and 69, presented with a history of a few years of progressive aphasia characterized by fluent output with normal grammar and syntax, anomia without loss of word meaning, and relatively spared repetition. They demonstrated striking deficits in visuospatial function for which they were lacking insight. Prominent hypometabolism was noted in the left occipitotemporal region and diffuse retention of PiB was noted. Posterior cortical atrophy may present focally with left occipitotemporal metabolism characterized clinically with a progressive fluent aphasia and prominent ventral visuospatial deficits with loss of insight.

Stimulate or degenerate: deep brain stimulation of the nucleus basalis Meynert in Alzheimer dementia

OBJECTIVE

Deep brain stimulation (DBS) is a therapeutically effective neurosurgical method originally applied in movement disorders. Over time, the application of DBS has increasingly been considered as a therapeutic option for several neuropsychiatric disorders, including Gilles de la Tourette syndrome, obsessive compulsive disorder, major depression and addiction. Latest research suggests beneficial effects of DBS in Alzheimer dementia (AD). Because of the high prevalence and the considerable burden of the disease, we endeavored to discuss and reveal the challenges of DBS in AD.

METHODS

Recent literature on the pathophysiology of AD, including translational data and human studies, has been studied to generate a fundamental hypothesis regarding the effects of electrical stimulation on cognition and to facilitate our ongoing pilot study regarding DBS of the nucleus basalis Meynert (NBM) in patients with AD.

RESULTS

It is hypothesized that DBS in the nucleus basalis Meynert could probably improve or at least stabilize memory and cognitive functioning in patients with AD by facilitating neural oscillations and by enhancing the synthesis of nerve growth factors.

CONCLUSIONS

Considering the large number of patients suffering from AD, there is a great need for novel and effective treatment methods. Our research provides insights into the theoretical background of DBS in AD. Providing that our hypothesis will be validated by our ongoing pilot study, DBS could be an opportunity in the treatment of AD.