2019 Alzheimer's disease facts and figures

Effect of early-stage Alzheimer's disease on household financial outcomes

Significant limitations and rapid declines in financial capacity are a hallmark of patients with early-stage Alzheimer's disease (AD). We use linked Health and Retirement Study and Medicare claims data spanning 1992-2014 to examine the effect of early-stage AD, from the start of first symptoms to diagnosis, on household financial outcomes. We estimate household fixed-effects models and examine continuous measures of liquid assets and net wealth, as well as dichotomous indicators for a large change in either outcome. We find robust evidence that early-stage AD places households at significant risk for large adverse changes in liquid assets. Further, we find some, but more limited, evidence that early-stage AD reduces net wealth. Our findings are consequential because financial vulnerability during the disease's early-stage impacts the ability of afflicted individuals and their families to pay for care in the disease's later stage. Additionally, the findings speak to the value that earlier diagnosis may provide by helping avert adverse financial outcomes that occur before the disease is currently diagnosable with available tools. These results also point to a potentially important role for financial institutions in helping reduce exposure of vulnerable elderly to poor outcomes.

Associations Between Caffeine Consumption, Cognitive Decline, and Dementia: A Systematic Review

BACKGROUND

Epidemiologic studies have provided inconclusive evidence for a protective effect of caffeine consumption on risk of dementia and cognitive decline.

OBJECTIVE

To summarize literature on the association between caffeine and 1) the risk of dementia and/or cognitive decline, and 2) cognitive performance in individuals with mild cognitive impairment (MCI) or dementia, and 3) to examine the effect of study characteristics by categorizing studies based on caffeine source, quantity and other possible confounders.

METHODS

We performed a systematic review of caffeine effects by assessing overall study outcomes; positive, negative or no effect. Our literature search identified 61 eligible studies performed between 1990 and 2020.

RESULTS

For studies analyzing the association between caffeine and the risk of dementia and/or cognitive decline, 16/57 (28%) studies including a total of 40,707/153,070 (27%) subjects reported positive study outcomes, and 30/57 (53%) studies including 71,219/153,070 (47%) subjects showed positive results that were dependent on study characteristics. Caffeine effects were more often positive when consumed in moderate quantities (100-400 mg/d), consumed in coffee or green tea, and in women. Furthermore, four studies evaluated the relationship between caffeine consumption and cognitive function in cognitively impaired individuals and the majority (3/4 [75% ]) of studies including 272/289 subjects (94%) reported positive outcomes.

CONCLUSION

This review suggests that caffeine consumption, especially moderate quantities consumed through coffee or green tea and in women, may reduce the risk of dementia and cognitive decline, and may ameliorate cognitive decline in cognitively impaired individuals.

Type 2 Diabetes Interacts With Alzheimer Disease Risk Factors to Predict Functional Decline

OBJECTIVE

The current study examined the interactive effect of type 2 diabetes and Alzheimer disease (AD) risk factors on the rate of functional decline in cognitively normal participants from the Alzheimer's Disease Neuroimaging Initiative.

METHODS

Participants underwent annual assessments that included the Functional Activities Questionnaire, an informant-rated measure of everyday functioning. Multilevel modeling, controlling for demographic variables and ischemic risk, examined the interactive effects of diabetes status (diabetes, n=69; no diabetes, n=744) and AD risk factors in the prediction of 5-year longitudinal change in everyday functioning. One model was run for each AD risk factor, including: objectively-defined subtle cognitive decline (Obj-SCD), and genetic susceptibility [apolipoprotein E ε4 (APOE ε4) as well as cerebrospinal fluid β-amyloid (Aβ), total tau (tau), and hyperphosphorylated tau (p-tau).

RESULTS

The 3-way diabetes×AD risk factor×time interaction predicted increased rates of functional decline in models that examined Obj-SCD, APOE ε4, tau, and p-tau positivity, but not Aβ positivity.

CONCLUSIONS

Participants with both diabetes and at least 1 AD risk factor (ie, Obj-SCD, APOE ε4, tau, and p-tau positivity) demonstrated faster functional decline compared with those without both risk factors (diabetes or AD). These findings have implications for early identification of, and perhaps earlier intervention for, diabetic individuals at risk for future functional difficulty.

Living in the Community With Dementia: Who Receives Paid Care?

OBJECTIVES

Paid caregivers (eg, home health aides and personal care attendants) provide hands-on care that helps individuals with dementia live in the community. This study (a) characterizes paid caregiving among community-dwelling individuals with dementia and (b) identifies factors associated with receipt of paid care.

DESIGN

Cross-sectional analysis.

SETTING

The 2015 National Health and Aging Trends Study (NHATS), a nationally representative study of Medicare recipients aged 65 years and older.

PARTICIPANTS

Community-dwelling individuals with dementia (n = 899).

MEASUREMENTS

Paid and family caregiving support was determined by participant or proxy report of help received with functional tasks. Multivariable logistic regression was used to examine factors associated with receipt of paid care. NHATS population sampling weights were used to produce national paid caregiving prevalence estimates.

RESULTS

Only 25.5% of community-dwelling individuals with dementia received paid care, and 10.8% received 20 hours or more of paid care per week. For those who received it, paid care accounted for approximately half of the 83 total caregiving hours (paid and family) that they received each week. Among the subgroup of individuals with advanced dementia (those with impairment in dressing, bathing, toileting, and managing medications and finances), nearly half (48.3%) received paid care. Multivariable analysis, adjusting for sociodemographic, family caregiving support, functional, and clinical characteristics, found that the odds of receiving paid care were higher among men (odds ratio [OR] = 1.91; 95% confidence interval [CI] = 1.24-2.95), the unmarried (OR = 2.20; 95% CI = 1.31-3.70), those with Medicaid (OR = 2.16; 95% CI = 1.27-3.66), and those requiring more help with activities of daily living (ADLs) (OR = 1.32; 95% CI = 1.18-1.48) and instrumental ADLs (OR = 1.29; 95% CI = 1.14-1.46).

CONCLUSIONS

New ways of making paid caregiving more accessible throughout the income spectrum are required to support family caregivers and respect the preferences of individuals with dementia to remain living in the community. J Am Geriatr Soc 68:186-191, 2019.

Novel “turn on–off” paper sensor based on nonionic conjugated polythiophene-coated CdTe QDs for efficient visual detection of cholinesterase activity

A novel conjugated polythiophene (CP) compound was successfully combined with CdTe quantum dots to improve their selectivity and sensitivity for the efficient visual detection of AChE activity via the color variation of CdTe/CP.

Pre-Diabetes, but not Type 2 Diabetes, Is Related to Brain Amyloid in Late Middle-Age

BACKGROUND

Type 2 diabetes is a dementia risk factor, but its relation to Alzheimer's disease (AD), the most common cause of dementia, is unclear.

OBJECTIVE

Our primary objective was to examine the association of pre-diabetes and type 2 diabetes with brain amyloid-β (Aβ), the putative main culprit of AD. Our secondary objective was to examine the association of pre-diabetes and type 2 diabetes with neurodegeneration, cerebrovascular disease (CVD), and memory performance.

METHODS

We conducted a cross-sectional study of 350 late middle-aged Hispanics without dementia in New York City. We classified diabetes status as normal glucose tolerance (NGT), pre-diabetes, and type 2 diabetes following American Diabetes Association criteria. Brain Aβ was ascertained as global Aβ standardized value uptake ratio using PET with 18F-Florbetaben. Neurodegeneration was operationalized as cortical thickness in regions affected by AD using MRI. CVD was operationalized as white matter hyperintensity volume (WMH) on MRI, and memory as performance with the selective reminding test (SRT).

RESULTS

Mean age was 64.15±3.34 years, 72.00% were women, and 35.43% were APOEɛ4 carriers. Pre-diabetes, but not type 2 diabetes, was associated with higher Aβ compared with NGT. Type 2 diabetes treatment was related to lower Aβ. Type 2 diabetes was related to lower cortical thickness, higher WMH, and lower SRT score.

CONCLUSION

Pre-diabetes, but not type 2 diabetes, is associated with higher brain Aβ in late middle age, and this observation could be explained by the relation of diabetes treatment with lower brain Aβ. Whether type 2 diabetes treatment lowers brain Aβ requires further study.

Enhancing student-pharmacists' professional development through community outreach with dementia population

INTRODUCTION

Misinterpreted or minimized sensations related to progressive neuronal loss are predictive of the prominent behavioral and psychological symptoms (BPSD) observed in dementia. Guidelines recommend nonpharmacologic interventions via sensory engagement be included in the standard of patient care. To facilitate implementation, collaboration with health care students equipped with nonpharmacologic strategies to manage BPSD should be encouraged. The aim of this study was to determine the impact of outreach participation on student-pharmacists' comfort levels and perceived communication ability when interacting with patients with dementia.

METHODS

During the sensory stimulation outreach, pharmacy students were paired with a patient with dementia to encourage fidget blanket use through patient-specific directions and demonstration. A single-group, pretest-posttest design was utilized to assess changes in students' comfort level and perceived communication ability prior to and immediately following outreach participation.

RESULTS

Twenty-six students attended between 1 and 5 outreaches. Students reported a statistically significant increase in comfort level while interacting with patients with dementia after attending their first (n = 26, Z = 2.754, P = .006), second (n = 16, Z = 2.124, P = .034), and third outreach (n = 12, Z = 2.449, P = .014). Students' weighted composite communication scores showed a statistically significant increase after their first (n = 26, Z = 3.309, P = .001) and third outreach experiences (n = 12, Z = 2.375, P = .018).

DISCUSSION

Participation in this sensory stimulation outreach improved students' comfort level and ability to communicate while interacting with patients with dementia. Greater exposure to the population through continued outreach participation was associated with a further increase in comfort level and perceived communication ability.

Effect of C-terminus amidation of Aβ39–42fragment derived peptides as potential inhibitors of Aβ aggregation

The C-terminus fragment (Val-Val-Ile-Ala) of amyloid-β is reported to inhibit the aggregation of the parent peptide. In an attempt to investigate the effect of sequential amino-acid scan and C-terminus amidation on the biological profile of the lead sequence, a series of tetrapeptides were synthesized using MW-SPPS. Peptide D-Phe-Val-Ile-Ala-NH₂ (12c) exhibited high protection against β-amyloid-mediated-neurotoxicity by inhibiting Aβ aggregation in the MTT cell viability and ThT-fluorescence assay. Circular dichroism studies illustrate the inability of Aβ₄₂ to form β-sheet in the presence of 12c, further confirmed by the absence of Aβ₄₂ fibrils in electron microscopy experiments. The peptide exhibits enhanced BBB permeation, no cytotoxicity along with prolonged proteolytic stability. In silico studies show that the peptide interacts with the key amino acids in Aβ, which potentiate its fibrillation, thereby arresting aggregation propensity. This structural class of designed scaffolds provides impetus towards the rational development of peptide-based-therapeutics for Alzheimer's disease (AD).

Amidated C-terminal fragment, Aβ_39–42 derived non-cytotoxic β-sheet breaker peptides exhibit excellent potency, enhanced bioavailability and improved proteolytic stability.

Characterizing Clinical and Neuropathological Traits of APOE Haplotypes in African Americans and Europeans

BACKGROUND

The APOEɛ4 allele is the largest genetic risk factor for late-onset Alzheimer's disease (AD). Recent literature suggested that the contribution of APOEɛ4 to AD risk could be population-specific, with ɛ4 conferring a lower risk to Blacks or African Americans.

OBJECTIVE

To investigate the effect of APOE haplotypes on AD risk in individuals with European ancestry (EU) and Blacks or African Americans (AA).

METHODS

We selected data from 1) the National Alzheimer's Coordinating Center: a total of 3,486 AD cases and 4,511 controls (N = 7,997, 60% female) with genotypes from the Alzheimer's Disease Genetics Consortium (ADGC), and 2) the Rush University Religious Orders Study and Memory and Aging Project (ROSMAP) cohort with 578 AD and 670 controls (N = 1,248, 60% female). Using ɛ3 homozygotes as the reference, we compared the association of various APOE haplotypes with the clinical and neuropathological correlates of dementia in AA and EU.

RESULTS

In both cohorts, we find no difference in the odds or age of onset of AD among the ɛ4-linked haplotypes defined by rs769449 within either AA or EU. Additionally, while APOEɛ4 was associated with a faster rate of decline, no differences were found in rate of decline, clinical or neuropathological features among the ɛ4-linked haplotypes. Further analysis with other variants near the APOE locus failed to identify any effect modification.

CONCLUSION

Our study finds similar effects of the ɛ4-linked haplotypes defined by rs769449 on AD as compared to ɛ3 in both AA and EU. Future studies are required to understand the heterogeneity of APOE conferred risk of AD among various genotypes and populations.

ABCA7 Genotype Moderates the Effect of Aerobic Exercise Intervention on Generalization of Prior Learning in Healthy Older African Americans

African Americans are at elevated risk for age-related cognitive decline, with double the prevalence of Alzheimer's disease (AD) compared to Caucasians Americans. Various behavioral, biological, and lifestyle factors may underlie this health disparity, but little is known about the relative importance and interactions among these different risk factors in African Americans. While the neuroprotective effects of aerobic exercise on biomarkers are well established, few studies have examined the differential benefits of exercise based on genetic risk for AD. Furthermore, evidence is limited regarding the potential moderating effects of ABCA7, a gene known to confer significantly greater AD risk in African Americans. In a case-control matched sample of 56 healthy older African Americans, we investigated the effect of an aerobic exercise intervention on a hippocampus-related assessment of generalization following rule learning, in individuals who were carriers of the ABCA7 rs3764650 non-risk (TT) or high-risk (GG) genotype. Following the exercise-intervention, the non-risk group made significantly fewer generalization errors, while there was no improvement in generalization for the high-risk group. For the controls, no changes in generalization scores were observed regardless of genotype status. Our results indicate that the ongoing adverse effects of ABCA7 high-risk genotype may diminish the benefits associated with aerobic exercise. As such, the potential disease-modifying effects of aerobic exercise on AD-related neuropathology may be limited to carriers of the ABCA7 rs3764650 non-risk genotype.

Family-centeredness in dementia care: what is the evidence?

Over the last decade, person-centered practices in care for adults with Alzheimer's disease and related dementias (AD/RD) has received significant attention from the health care and social service literature, though less attention has been paid to family-centered care (FCC). Initially conceptualized for application in pediatric care, FCC is an approach where clinicians develop partnerships with care recipients' family members and views family members as having expertise to contribute to the clinical team. More recently, FCC has been extended to the literature on AD/RD care, though little is known about the extent to which family-centered interventions have been developed for use in AD/RD clinical practice, or the effectiveness of family-centered care for this population. To contribute to gaps in scholarship, this systematic review identified and evaluated intervention studies examining FCC in AD/RD clinical care. Implications for research and practice are discussed.

Genetic Risk for Alzheimer's Disease Moderates the Association Between Medial Temporal Lobe Volume and Episodic Memory Performance Among Older Adults

BACKGROUND

A complex set of interactions between biological, genetic, and environmental factors likely underlies the development of Alzheimer's disease (AD). Identifying which of these factors is most associated with AD is important for early diagnosis and treatment.

OBJECTIVE

We sought to examine genetic risk and structural brain volume on episodic memory in a sample of older adults ranging from cognitively normal to those diagnosed with AD.

METHODS

686 adults (55-91 years old) completed a 3T MRI scan, baseline cognitive assessments, and biospecimen collection through the Alzheimer's Disease Neuroimaging Initiative. Hierarchical linear regression analyses examined main and interaction effects of medial temporal lobe (MTL) volume and polygenic hazard score (PHS), indicating genetic risk for AD, on a validated episodic memory composite score.

RESULTS

Genetic risk moderated the relationship between MTL volume and memory, such that individuals with high PHS and lower hippocampal and entorhinal volume had lower memory composite scores [ΔF (1,677) = 4.057, p = 0.044, ΔR2 = 0.002]. Further analyses showed this effect was driven by the left hippocampus [ΔF(1,677) = 5.256, p = 0.022, ΔR2 = 0.003] and right entorhinal cortex [ΔF (1,677) = 6.078, p = 0.014, ΔR2 = 0.003].

CONCLUSIONS

Among those with high genetic risk for AD, lower volume was associated with poorer memory. Results suggest that the interaction between AD genetic risk and MTL volume increases the likelihood for memory impairment among older adults. Results from this study suggest that genetic risk and brain volume should be considered key factors in tracking cognitive decline.

Pharmaceutical Treatment for Alzheimer's Disease and Related Dementias: Utilization and Disparities

BACKGROUND

Four prescription drugs (donepezil, galantamine, memantine, and rivastigmine) are approved by the US FDA to treat symptoms of Alzheimer's disease (AD). Even modest effectiveness could potentially reduce the population-level burden of AD and related dementias (ADRD), especially for women and racial/ethnic minorities who have higher incidence of ADRD.

OBJECTIVE

Describe the prevalence of antidementia drug use and timing of initiation relative to ADRD diagnosis among a nationally representative group of older Americans, and if there are disparities in prevalence and timing by sex and race/ethnicity.

METHODS

Descriptive analyses and logistic regressions of Medicare claims (2008-2016) for beneficiaries who had an ADRD or dementia-related symptom diagnosis, or use of an FDA approved drug for AD. We investigate prevalence of use and timing of treatment initiation relative to ADRD diagnosis across time and beneficiary characteristics (age, sex, race/ethnicity, socioeconomic status, comorbidities).

RESULTS

Among persons diagnosed with ADRD or related symptoms, 33.3% used an approved drug over the study period. Odds of use was higher among Whites than non-Whites. Among ADRD drug users, 40% initiated use within 6 months of the initial ADRD or related symptoms diagnosis, and 16% initiated prior to a diagnosis. We observed disparities by race/ethnicity: 28% of Asians, 24% of Hispanics, 16% of Blacks, and 15% of Whites initiated prior to diagnosis.

CONCLUSIONS

The use of antidementia drugs is relatively low and varies widely by race/ethnicity. Heterogeneity in timing of initiation and use may affect health and cost outcomes, but these effects merit further study.

Development and Validation of eRADAR: A Tool Using EHR Data to Detect Unrecognized Dementia

OBJECTIVES

Early recognition of dementia would allow patients and their families to receive care earlier in the disease process, potentially improving care management and patient outcomes, yet nearly half of patients with dementia are undiagnosed. Our aim was to develop and validate an electronic health record (EHR)-based tool to help detect patients with unrecognized dementia (EHR Risk of Alzheimer's and Dementia Assessment Rule [eRADAR]).

DESIGN

Retrospective cohort study.

SETTING

Kaiser Permanente Washington (KPWA), an integrated healthcare delivery system.

PARTICIPANTS

A total of 16 665 visits among 4330 participants in the Adult Changes in Thought (ACT) study, who undergo a comprehensive process to detect and diagnose dementia every 2 years and have linked KPWA EHR data, divided into development (70%) and validation (30%) samples.

MEASUREMENTS

EHR predictors included demographics, medical diagnoses, vital signs, healthcare utilization, and medications within the previous 2 years. Unrecognized dementia was defined as detection in ACT before documentation in the KPWA EHR (ie, lack of dementia or memory loss diagnosis codes or dementia medication fills).

RESULTS

Overall, 1015 ACT visits resulted in a diagnosis of incident dementia, of which 498 (49%) were unrecognized in the KPWA EHR. The final 31-predictor model included markers of dementia-related symptoms (eg, psychosis diagnoses, antidepressant fills), healthcare utilization pattern (eg, emergency department visits), and dementia risk factors (eg, cerebrovascular disease, diabetes). Discrimination was good in the development (C statistic = .78; 95% confidence interval [CI] = .76-.81) and validation (C statistic = .81; 95% CI = .78-.84) samples, and calibration was good based on plots of predicted vs observed risk. If patients with scores in the top 5% were flagged for additional evaluation, we estimate that 1 in 6 would have dementia.

CONCLUSION

The eRADAR tool uses existing EHR data to detect patients with good accuracy who may have unrecognized dementia. J Am Geriatr Soc 68:103-111, 2019.

Retinal analysis of a mouse model of Alzheimer's disease with multicontrast optical coherence tomography

Significance. Recent Alzheimer's disease (AD) patient studies have focused on retinal analysis, as the retina is the only part of the central nervous system that can be imaged noninvasively by optical methods. However, as this is a relatively new approach, the occurrence and role of retinal pathological features are still debated. Aim. The retina of an APP/PS1 mouse model was investigated using multicontrast optical coherence tomography (OCT) in order to provide a documentation of what was observed in both transgenic and wild-type mice. Approach. Both eyes of 24 APP/PS1 transgenic mice (age: 45 to 104 weeks) and 15 age-matched wild-type littermates were imaged by the custom-built OCT system. At the end of the experiment, retinas and brains were harvested from a subset of the mice (14 transgenic, 7 age-matched control) in order to compare the in vivo results to histological analysis and to quantify the cortical amyloid beta plaque load. Results. The system provided a combination of standard reflectivity data, polarization-sensitive data, and OCT angiograms. Qualitative and quantitative information from the resultant OCT images was extracted on retinal layer thickness and structure, presence of hyper-reflective foci, phase retardation abnormalities, and retinal vasculature. Conclusions. Although multicontrast OCT revealed abnormal structural properties and phase retardation signals in the retina of this APP/PS1 mouse model, the observations were very similar in transgenic and control mice.

Sex Differences in the Phosphoproteomic Profiles of APP/PS1 Mice after Chronic Unpredictable Mild Stress

Approximately two-thirds of those suffering with Alzheimer's disease (AD) are women, however, the biological mechanisms underlying this sex divergence of AD prevalence remain unknown. Previous research has shown sex-specific biochemical differences that bias female mice toward pro-AD signaling on the phosphoproteomic level via corticotropin releasing factor (CRF) receptor 1 activation after CRF overexpression. Here we aimed to determine if chronic stress would induce a similar response in AD mouse models. We stressed 4-month-old APP/PS1 mice using a chronic unpredictable mild stress (CUMS) paradigm for up to 1 month. Following CUMS and behavioral assessments, we quantified whole protein and phosphoprotein levels in the cortex of stressed and non-stressed APP/PS1 mice using mass spectrometry-based proteomics. While there were no statistically significant differences at the total protein and peptide abundance levels, we found 909 and 841 statistically significant phosphopeptides between stressed and unstressed females and males, respectively, using a false discovery rate of 5%. Of these significant phosphopeptides, only 301 were the same in males and females. These results indicate that while both males and females undergo protein phosphorylation changes following stress, the peptides that are phosphorylated differ between sexes. We then used Metacore analysis to determine which biological pathways were affected. We found that several pathways were changed differently between male and female mice including NMDA receptor trafficking, cytoskeleton organization, and tau pathology. The differing biological pathways affected between males and females in response to chronic stress may help us to better understand why women are at a higher risk of AD.

How Accurately Do Patients and Their Care Partners Report Results of Amyloid-β PET Scans for Alzheimer's Disease Assessment?

BACKGROUND

Amyloid-β PET scans will likely become an integral part of the diagnostic evaluation for Alzheimer's disease if Medicare approves reimbursement for the scans. However, little is known about patients' and their care partners' interpretation of scan results.

OBJECTIVE

This study seeks to understand how accurately patients with mild cognitive impairment (MCI) or dementia and their care partners report results of amyloid-β PET scans and factors related to correct reporting.

METHODS

A mixed-methods approach was used to analyze survey data from 1,845 patient-care partner dyads and responses to open-ended questions about interpretation of scan results from a sub-sample of 200 dyads.

RESULTS

Eighty-three percent of patients and 85% of care partners correctly reported amyloid-β PET scan results. Patients' higher cognitive function was associated with a small but significant decrease in the predicted probability of not only patients accurately reporting scan results (ME: -0.004, 95% CI: -0.007, -0.000), but also care partners accurately reporting scan results (ME: -0.006, 95% CI: -0.007, -0.001), as well as decreased concordance between patient and care partner reports (ME: -0.004, 95% CI: -0.007, -0.001). Content analysis of open-ended responses found that participants who reported the scan results incorrectly exhibited more confusion about diagnostic terminology than those who correctly reported the scan results.

CONCLUSION

Overall, patients with MCI or dementia showed high rates of accurate reporting of amyloid-β PET scan results. However, responses to questions about the meaning of the scan results highlight the need for improved provider communication, including providing written explanations and better prognostic information.

Ameliorating amyloid aggregation through osmolytes as a probable therapeutic molecule against Alzheimer's disease and type 2 diabetes

Large numbers of neurological and metabolic disorders occurring in humans are induced by the aberrant growth of aggregated or misfolded proteins.

BESI: Behavioral and Environmental Sensing and Intervention for Dementia Caregiver Empowerment-Phases 1 and 2

BACKGROUND AND OBJECTIVES

Caregiver burden associated with dementia-related agitation is one of the commonest reasons a community-dwelling person with dementia (PWD) transitions to a care facility. Behavioral and Environmental Sensing and Intervention for Dementia Caregiver Empowerment (BESI) is a system of body-worn and in-home sensors developed to provide continuous, noninvasive agitation assessment and environmental context monitoring to detect early signs of agitation and its environmental triggers.

RESEARCH DESIGN AND METHODS

This mixed methods, remote ethnographic study is explored in a 3-phase, multiyear plan. In Phase 1, we developed and refined the BESI system and completed usability studies. Validation of the system and the development of dyad-specific models of the relationship between agitation and the environment occurred in Phase 2.

RESULTS

Phases 1 and 2 results facilitated targeted changes in BESI, thus improving its overall usability for the final phase of the study, when real-time notifications and interventions will be implemented.

CONCLUSION

Our results show a valid relationship between the presence of dementia related agitation and environmental factors and that persons with dementia and their caregivers prefer a home-based monitoring system like BESI.

Combining Chalcones with Donepezil to Inhibit Both Cholinesterases and Aβ Fibril Assembly

The fact that the number of people with Alzheimer's disease is increasing, combined with the limited availability of drugs for its treatment, emphasize the need for the development of novel effective therapeutics for treating this brain disorder. Herein, we focus on generating 12 chalcone-donepezil hybrids, with the goal of simultaneously targeting amyloid-β (Aβ) peptides as well as cholinesterases (i.e., acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)). We present the design, synthesis, and biochemical evaluation of these two series of novel 1,3-chalcone-donepezil (15a-15f) or 1,4-chalcone-donepezil (16a-16f) hybrids. We evaluate the relationship between their structures and their ability to inhibit AChE/BChE activity as well as their ability to bind Aβ peptides. We show that several of these novel chalcone-donepezil hybrids can successfully inhibit AChE/BChE as well as the assembly of N-biotinylated Aβ(1-42) oligomers. We also demonstrate that the Aβ binding site of these hybrids differs from that of Pittsburgh Compound B (PIB).

Alzheimer's disease: A clinical perspective and future nonhuman primate research opportunities

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that is the sixth leading cause of death and the most common cause of dementia worldwide. Over the last few decades, significant advancements have been made in our understanding of AD by investigating the molecular mechanisms underlying amyloid-β and tau pathology. Despite this progress, no disease-modifying treatments exist for AD, an issue that will exacerbated by the rising costs and prevalence of the disorder. Moreover, effective therapies to address the devastating cognitive and behavioral symptoms are also urgently needed. This perspective focuses on the value of nonhuman primate (NHP) models in bridging the molecular, circuit, and behavioral levels of analysis to better understand the complex genetic and environmental/lifestyle factors that contribute to AD pathogenesis. These investigations could provide an opportunity for translating our understanding of the pathogenesis and physiological mechanisms underlying AD and related disorders into new diagnostic approaches and disease-modifying therapies to prevent disease or restore brain function for symptomatic individuals.

Validation of the Latin American Spanish version of the face-name associative memory exam in a Colombian Sample

OBJECTIVE

The Face-Name Associative Memory Exam (FNAME) has been used to detect subtle cognitive changes in clinically normal older adults at increased risk for Alzheimer's disease. FNAME assesses learning and delayed recall for face-name pairs. The aim of this study is to introduce a Latin American Spanish version of the FNAME (LAS-FNAME), examine its psychometric properties, and provide preliminary normative data in a sample of clinically normal, Spanish-speaking individuals from Antioquia, Colombia.

METHOD

59 clinically-normal individuals (71% females) were recruited by the Grupo de Neurociencias in Antioquia (Colombia). Age ranged from 27 to 82 years (M = 50.31, SD = 15.32) and years of education ranged from 2 to 17 years (M = 9.02, SD = 4.11). All participants completed the LAS-FNAME and a brief neuropsychological evaluation. We examined associations between age, education, and sex and performance on the LAS-FNAME. Internal consistency, convergent and discriminant validity were also assessed. Test-restest reliability was computed for a subset of participants (n = 32).

RESULTS

LAS-FNAME exhibited moderate convergent validity with other memory measures (Free and Cued Selective Reminding Scale, r _s=.465, p<.01; Wechsler Memory Scale III - Logical Memory Delayed Recall, r _s=.479, p<.01). The subscales of the LAS-FNAME exhibited adequate internal consistency (α=.825). Test-retest reliability analyses demonstrated consistency of scores over time. Normative data was stratified by age (<50, 50-65, >65) and low and high educational attainment (≤8 and >8 years of education, respectively).

CONCLUSIONS

The LAS-FNAME is a valid and reliable measure to assess memory in clinically normal, Spanish-speaking individuals from Colombia for clinical and research purposes.

Cognitive symptoms of Alzheimer's disease: clinical management and prevention

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by the accumulation of amyloid β in the form of extracellular plaques and by intracellular neurofibrillary tangles, with eventual neurodegeneration and dementia. There is currently no disease-modifying treatment though several symptomatic medications exist with modest benefit on cognition. Acetylcholinesterase inhibitors have a consistent benefit across all stages of dementia; their benefit in mild cognitive impairment and prodromal AD is unproven. Memantine has a smaller benefit on cognition overall which is limited to the moderate to severe stages, and the combination of a cholinesterase inhibitor and memantine may have additional efficacy. Evidence for the efficacy of vitamin E supplementation and medical foods is weak but might be considered in the context of cost, availability, and safety in individual patients. Apparently promising disease-modifying interventions, mostly addressing the amyloid cascade hypothesis of AD, have recently failed to demonstrate efficacy so novel approaches must be considered.

Modification of Aβ Peptide Aggregation via Covalent Binding of a Series of Ru(III) Complexes

Alzheimer's disease (AD) is the most common form of dementia, leading to loss of cognition, and eventually death. The disease is characterized by the formation of extracellular aggregates of the amyloid-beta (Aβ) peptide and neurofibrillary tangles of tau protein inside cells, and oxidative stress. In this study, we investigate a series of Ru(III) complexes (Ru-N) derived from NAMI-A in which the imidazole ligand has been substituted for pyridine derivatives, as potential therapeutics for AD. The ability of the Ru-N series to bind to Aβ was evaluated by NMR and ESI-MS, and their influence on the Aβ peptide aggregation process was investigated via electrophoresis gel/western blot, TEM, turbidity, and Bradford assays. The complexes were shown to bind covalently to the Aβ peptide, likely via a His residue. Upon binding, the complexes promote the formation of soluble high molecular weight aggregates, in comparison to peptide precipitation for peptide alone. In addition, TEM analysis supports both amorphous and fibrillar aggregate morphology for Ru-N treatments, while only large amorphous aggregates are observed for peptide alone. Overall, our results show that the Ru-N complexes modulate Aβ peptide aggregation, however, the change in the size of the pyridine ligand does not substantially alter the Aβ aggregation process.

The need for improved cognitive, hearing and vision assessments for older people with cognitive impairment: a qualitative study

Background

Hearing and vision (sensory) impairments are highly prevalent in people with dementia (PwD) and exacerbate the impact of living with dementia. Assessment of sensory or cognitive function may be difficult if people have concurrent dual or triple impairments. Most standard cognitive assessment tests are heavily dependent on having intact hearing and vision, and impairments in these domains may render the assessments unreliable or even invalid. Likewise, dementia may impede on the accurate reporting of symptoms that is required for most hearing and vision assessments. Thus, there is an urgent need for hearing, vision and cognitive assessment strategies to be adapted to ensure that appropriate management and support can be provided.

Objective

To explore the perspectives of PwD and the care partners regarding the need for accurate hearing, vision and cognitive assessments.

Methods

We conducted focus groups and semi-structured interviews regarding the clinical assessment for cognitive, hearing and visual impairment. Participants (n = 18) were older adults with mild to moderate dementia and a sensory impairment as well as their care partners (e.g. a family member) (n = 15) at three European sites. The qualitative material was analysed according to Mayring’s summative content analysis approach.

Results

Participants reported that hearing, vision and cognitive assessments were not appropriate to the complex needs of PwD and sensory comorbidity and that challenges in communication with professionals and conveying unmet needs and concerns by PwD were common in all three types of clinical assessments. They felt that information about and guidance regarding support for the condition was not adequate in the assessments and that information sharing among the professionals regarding the concurrent problems was limited. Professionals were reported as being concerned only with problems related to their own discipline and had limited regard for problems in other domains which might impact on their own assessments.

Conclusions

The optimal assessment and support for PwD with multiple impairments, more comprehensive, yet easy to understand, information regarding these linked to conditions and corrective device use is needed. Communication among health care professionals relevant to hearing, vision and cognition needs to be improved.

Lifelong choline supplementation ameliorates Alzheimer's disease pathology and associated cognitive deficits by attenuating microglia activation

Currently, there are no effective therapies to ameliorate the pathological progression of Alzheimer's disease (AD). Evidence suggests that environmental factors may contribute to AD. Notably, dietary nutrients are suggested to play a key role in mediating mechanisms associated with brain function. Choline is a B-like vitamin nutrient found in common foods that is important in various cell functions. It serves as a methyl donor and as a precursor for production of cell membranes. Choline is also the precursor for acetylcholine, a neurotransmitter which activates the alpha7 nicotinic acetylcholine receptor (α7nAchR), and also acts as an agonist for the Sigma-1 R (σ1R). These receptors regulate CNS immune response, and their dysregulation contributes to AD pathogenesis. Here, we tested whether dietary choline supplementation throughout life reduces AD-like pathology and rescues memory deficits in the APP/PS1 mouse model of AD. We exposed female APP/PS1 and NonTg mice to either a control choline (1.1 g/kg choline chloride) or a choline-supplemented diet (5.0 g/kg choline chloride) from 2.5 to 10 months of age. Mice were tested in the Morris water maze to assess spatial memory followed by neuropathological evaluation. Lifelong choline supplementation significantly reduced amyloid-β plaque load and improved spatial memory in APP/PS1 mice. Mechanistically, these changes were linked to a decrease of the amyloidogenic processing of APP, reductions in disease-associated microglial activation, and a downregulation of the α7nAch and σ1 receptors. Our results demonstrate that lifelong choline supplementation produces profound benefits and suggest that simply modifying diet throughout life may reduce AD pathology.

The retinal choroid as an oculovascular biomarker for Alzheimer's dementia: A histopathological study in severe disease

INTRODUCTION

Previous in vivo optical coherence tomography studies have proposed the retinal choroid as a potential oculovascular biomarker for Alzheimer's disease (AD). However, the clinical use of the choroid as a purported surrogate marker remains poorly understood. We pursued a histopathological approach to assess choroidal thickness and vascular morphology in severe disease.

METHODS

Human postmortem tissues from 8 patients with AD (mean age: 80.1 ± 12.7 years) and from 11 age-matched controls (mean age: 78.4 ± 16.57 years) were analyzed. Thickness, area, and vascularity of the retinal choroid and its sublayers were measured from the nasal and temporal quadrants of the superior retina.

RESULTS

Nasally, the choroid was thinner in the patients with AD than in the controls (22% thickness reduction; P < .001), but to our surprise, the choroid was thicker in the patients with AD than in the controls (~60% increase; P < .03) within the macula, temporally. The choroidal area was also significantly greater in the patients with AD than in the controls (~60% increase; P < .03). Choroidal thickening in AD was strongly correlated with the stromal vessel number (R2 = 0.96, P < .001).

DISCUSSION

We found significant differences in the retinal choroid by layer and by region, nasally and temporally with respect to the optic nerve. Intriguingly, the choroid was markedly thicker in the central macular region and was strongly associated with vessel number in the stromal vascular layer. These quantified histological findings in severe disease expand our understanding of vascular pathology in AD and suggest vascularity as a potential biomarker supplementary to thickness when evaluating the retinal choroid in AD.

Sex Differences in the Neural Correlates of Spatial Context Memory Decline in Healthy Aging

Aging is associated with episodic memory decline and alterations in memory-related brain function. However, it remains unclear if age-related memory decline is associated with similar patterns of brain aging in women and men. In the current task fMRI study, we tested the hypothesis that there are sex differences in the effect of age and memory performance on brain activity during episodic encoding and retrieval of face–location associations (spatial context memory). Forty-one women and 41 men between the ages of 21 and 76 years participated in this study. Between-group multivariate partial least squares analysis of the fMRI data was conducted to directly test for sex differences and similarities in age-related and performance-related patterns of brain activity. Our behavioral analysis indicated no significant sex differences in retrieval accuracy on the fMRI tasks. In relation to performance effects, we observed similarities and differences in how retrieval accuracy related to brain activity in women and men. Both sexes activated dorsal and lateral PFC, inferior parietal cortex, and left parahippocampal gyrus at encoding, and this supported subsequent memory performance. However, there were sex differences in retrieval activity in these same regions and in lateral occipital-temporal and ventrolateral PFC. In relation to age effects, we observed sex differences in the effect of age on memory-related activity within PFC, inferior parietal cortex, parahippocampal gyrus, and lateral occipital-temporal cortices. Overall, our findings suggest that the neural correlates of age-related spatial context memory decline differ in women compared with men.

Methyl-CpG Binding Protein 2 in Alzheimer Dementia

Despite decades of research on Alzheimer disease, understanding the complexity of the genetic and molecular interactions involved in its pathogenesis remains far from our grasp. Methyl-CpG Binding Protein 2 (MeCP2) is an important epigenetic regulator enriched in the brain, and recent findings have implicated MeCP2 as a crucial player in Alzheimer disease. Here, we provide comprehensive insights into the pathophysiological roles of MeCP2 in Alzheimer disease. In particular, we focus on how the alteration of MeCP2 expression can impact Alzheimer disease through risk genes, amyloid-β and tau pathology, cell death and neurodegeneration, and cellular senescence. We suggest that Alzheimer disease can be adversely affected by upregulated MeCP2-dependent repression of risk genes (MEF2C, ADAM10, and PM20D1), increased tau accumulation, and neurodegeneration through neuronal cell death (excitotoxicity and apoptosis). In addition, we propose that the progression of Alzheimer disease could be caused by reduced MeCP2-mediated enhancement of astrocytic and microglial senescence and consequent glial SASP (senescence-associated secretory phenotype)-dependent neuroinflammation. We surmise that any imbalance in MeCP2 function would accelerate or cause Alzheimer disease pathogenesis, implying that MeCP2 may be a potential drug target for the treatment and prevention of Alzheimer disease.

Patient and Caregiver Outcomes and Experiences With Team-Based Memory Care: A Mixed Methods Study

Patients with dementia and their caregivers need ongoing educational and psychosocial support to manage their complex diagnosis. This mixed methods study evaluated the impact of a memory clinic with an embedded dementia navigator on the experiences and health outcomes of patients with dementia and their caregivers. At the 12-month follow-up, patients receiving memory clinic services (n = 238) had higher emergency department visits than a matched cohort with dementia (n = 938), although hospitalizations did not differ. Patient quality of life and caregiver burden scores also did not differ between baseline and 12-months. Interviews revealed that caregivers (n = 12) valued the educational and social support components of the memory clinic and perceived that the clinic had a positive impact on their experiences. Findings suggest that this embedded navigator model is useful for addressing caregiver needs and may have potential to stem increases in caregiver burden and patient quality of life that occur with disease progression.

Synthetic review of financial capacity in cognitive disorders: Foundations, interventions, and innovations

Purpose of review

Financial capacity (FC) is a complex, multi-dimensional construct that changes over the lifespan and commonly becomes impaired as individuals age and develop dementia. Impaired FC results in several important negative outcomes including loss of independence and increased victimization and abuse. The goal of this review is to synthesize current knowledge of the assessment and intervention of impaired financial capacity in order to propose its further development in the context of technological advancements.

Recent Findings

Current methods of assessing FC are based on conceptual foundations that include judgment, procedural, and other pragmatic skills. The neurocognitive correlates of FC include basic arithmetic skills, attention, and visual memory. These cognitive domains are presently assessed through clinical and neuropsychological evaluation as well as instruments specifically designed to assess financial capacity. Despite having a firm conceptual and neurocognitive foundation, current assessment methods of FC are limited by their ability to be flexible, individualizable, or scalable.

Summary

Computer and software technologies such as artificial intelligence, virtual reality, and the internet of things are exciting tools to achieve the ultimate goal of developing measures that allow patients to maintain or support maximal independence in financial functioning. These tools will allow for contemporaneous and ecologically valid assessment and would be useful to legal professionals and clinicians in determinations of financial competency and capacity. Moreover, interventions that provide safety and monitoring while allowing patients maximal autonomy of preserved financial abilities are needed.

The Rules of Engagement: Do Microglia Seal the Fate in the Inverse Relation of Glioma and Alzheimer's Disease?

Microglia, the immune cells of the brain, play a major role in the maintenance of brain homeostasis and constantly screen the brain environment to detect any infection or damage. Once activated by a stimulus, microglial cells initiate an immune response followed by the resolution of brain inflammation. A failure or deviation in the housekeeping function of these guardian cells can lead to multiple diseases, including brain cancer and neurodegenerative diseases such as Alzheimer's disease (AD). A small number of studies have investigated the causal relation of both diseases, thereby revealing an inverse relationship where cancer patients have a reduced risk to develop AD and vice versa. In this review, we aim to shed light on the role of microglia in the fate to develop specifically glioma as one type of cancer or AD. We will examine the common and/or opposing genetic predisposition as well as associated pathways of these diseases to unravel a possible involvement of microglia in the occurrence of either disease. Lastly, a set of guidelines will be proposed for future research and diagnostics to clarify and improve the knowledge on the role of microglia in the decision toward one pathology or another.

Detection of early-stage Alzheimer's pathology using blood-based autoantibody biomarkers in elderly hip fracture repair patients

Post-operative delirium (POD) is the most common complication following major surgery in non-demented older (>65 y/o) patients. Patients experiencing POD show increased risk for future cognitive decline, including mild cognitive impairment (MCI) and Alzheimer’s disease (AD) and, conversely, patients with cognitive decline at surgery show increased risk for POD. Here, we demonstrate that a previously established panel of AD-driven MCI (ADMCI) autoantibody (aAB) biomarkers can be used to detect prodromal AD pre-surgically in individuals admitted into the hospital for hip fracture repair (HFR) surgery. Plasma from 39 STRIDE (STRIDE: A Strategy to Reduce the Incidence of Postoperative Delirium in Elderly Patients) HFR patients and sera from 25 age- and sex-matched non-demented and non-surgical controls were screened using human protein microarrays to measure expression of a panel of 44 previously identified MCI aAB biomarkers. The predictive classification accuracy of the aAB biomarker panel was evaluated using Random Forest (RF). The ADMCI aAB biomarkers successfully distinguished 21 STRIDE HFR patients (CDR = 0.5) from 25 matched non-surgical controls with an overall accuracy of 91.3% (sensitivity = 95.2%; specificity = 88.0%). The ADMCI aAB panel also correctly identified six patients with preoperative CDR = 0 who later converted to CDR = 0.5 or >1 at one-year follow-up. Lastly, the majority of cognitively normal (CDR = 0) STRIDE HFR subjects that were positive for CSF AD biomarkers based on the A/T/N classification system were likewise classified as ADMCI aAB-positive using the biomarker panel. Results suggest that pre-surgical detection of ADMCI aAB biomarkers can readily identify HFR patients with likely early-stage AD pathology using pre-surgery blood samples, opening up the potential for early, blood-based AD detection and improvements in peri- and postoperative patient management.

The Brain Health Champion study: Health coaching changes behaviors in patients with cognitive impairment

INTRODUCTION

Converging evidence suggests that increasing healthy behaviors may slow or prevent cognitive decline.

METHODS

We piloted a six-month, randomized, controlled investigation of 40 patients with mild dementia, mild cognitive impairment, or subjective cognitive decline. The intervention consisted of weekly motivational interviewing phone calls and three visits with a "Brain Health Champion" health coach, who guided participants to achieve personalized goals. Changes in behavior were measured using validated questionnaires.

RESULTS

Compared with the standard-of-care control group, Brain Health Champion participants had statistically significant and clinically meaningful increases in physical activity (Cohen's d = 1.37, P < .001), adherence to the Mediterranean diet (Cohen's d = 0.87, P = .016), cognitive/social activity (Cohen's d = 1.09, P = .003), and quality of life (Cohen's d = 1.23, P < .001). The magnitude of behavior change strongly predicted improvement in quality of life.

DISCUSSION

Our results demonstrate the feasibility and potential efficacy of a health coaching approach in changing health behaviors in cognitively impaired and at-risk patients.

Effectiveness of Combined Cognitive and Physical Interventions to Enhance Functioning in Older Adults With Mild Cognitive Impairment: A Systematic Review of Randomized Controlled Trials

Background and Objectives

Cognitive training delivered in conjunction with physical activity, may help to optimize aging and delay or prevent dementia in individuals with mild cognitive impairment (MCI). However, their efficacy is less well studied compared to pharmaceutical treatments. This systematic review synthesizes the emerging evidence on combined cognitive-physical interventions for enhancing functioning in older adults with MCI, with implications for practice and research.

Research Design and Methods

We searched the PubMed, PsycINFO, Ageline, Medline, Web of Science and ProQuest databases, and hand-searched articles published between July 2013 and November 2018. Only randomized controlled trials which incorporated cognitive and physical components targeted to individuals with MCI over the age of 50 were eligible. Our search yielded 10 eligible, independent articles.

Results

Intervention participants with MCI self-reported, or demonstrated, improved functioning across a range of cognitive (global cognitive function, executive function, processing speed, memory, attention, mood, emotion, motivation, brain cortex, orientation), and physical (gait, balance, mobility) outcomes. Interventions which combined cognitive-physical training were comparable to those which isolated these same elements, in terms of their effects on executive function, processing speed, attention, mood, and cardiorespiratory fitness.

Discussion and Implications

There is preliminary evidence to support the positive effects of multicomponent interventions to improve cognitive-motor abilities in older adults at risk of developing dementia. The strength of this research evidence is, however, limited. Longitudinal studies are needed to determine whether these effects are maintained over time. The optimal intervention intensity and length also need to be established.

Disparities in Dementia Occurrence and Rate of Cognitive Decline Between African American and White Long-Term Care Residents

The objective of the current study was to investigate possible racial disparities in dementia among long-term care (LTC) residents. Participants were 1,239 residents (age ≥50) from 61 nursing home and assisted living facilities in Maryland. Retrospective analysis was performed to compare Brief Cognitive Assessment Tool (BCAT®) scores between African American and White participants. African American participants had 1.43 times greater odds of dementia and 1.86 times greater odds of severe-stage dementia than White residents. African American residents were significantly younger than their White peers by approximately 9 years within mild-moderate dementia levels and by 5 years at the severe stage. The rate of cognitive decline did not significantly differ by race despite a more negative curvilinear relationship between BCAT scores and age for African American participants than White participants. Implications of these findings are discussed for successful resident-centered care in LTC settings as well as for care transitions. [Research in Gerontological Nursing, xx(x), xx-xx.].

The Effects of APOE and ABCA7 on Cognitive Function and Alzheimer's Disease Risk in African Americans: A Focused Mini Review

African Americans have double the prevalence of Alzheimer's disease (AD), as compared to European Americans. However, the underlying causes of this health disparity are due to a multitude of environmental, lifestyle, and genetic factors that are not yet fully understood. Here, we review the effects of the two largest genetic risk factors for AD in African Americans: Apolipoprotein E (APOE) and ABCA7. We will describe the direct effects of genetic variation on neural correlates of cognitive function and report the indirect modulating effects of genetic variation on modifiable AD risk factors, such as aerobic fitness. As a means of integrating previous findings, we present a novel schematic diagram to illustrate the many factors that contribute to AD risk and impaired cognitive function in older African Americans. Finally, we discuss areas that require further inquiry, and stress the importance of racially diverse and representative study populations.

Longitudinal analysis of dementia diagnosis and specialty care among racially diverse Medicare beneficiaries

INTRODUCTION

There is insufficient understanding of diagnosis of etiologic dementia subtypes and contact with specialized dementia care among older Americans.

METHODS

We quantified dementia diagnoses and subsequent health care over five years by etiologic subtype and physician specialty among Medicare beneficiaries with incident dementia diagnosis in 2008/09 (226,604 persons/714,015 person-years).

RESULTS

Eighty-five percent of people were diagnosed by a nondementia specialist physician. Use of dementia specialists within one year (22%) and five years (36%) of diagnosis was low. "Unspecified" dementia diagnosis was common, higher among those diagnosed by nondementia specialists (33.2%) than dementia specialists (21.6%). Half of diagnoses were Alzheimer's disease.

DISCUSSION

Ascertainment of etiologic dementia subtype may inform hereditary risk and facilitate financial and care planning. Use of dementia specialty care was low, particularly for Hispanics and Asians, and associated with more detection of etiological subtype. Dementia-related professional development for nonspecialists is urgent given their central role in dementia diagnosis and care.

Alcohol drinking exacerbates neural and behavioral pathology in the 3xTg-AD mouse model of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that represents the most common cause of dementia in the United States. Although the link between alcohol use and AD has been studied, preclinical research has potential to elucidate neurobiological mechanisms that underlie this interaction. This study was designed to test the hypothesis that nondependent alcohol drinking exacerbates the onset and magnitude of AD-like neural and behavioral pathology. We first evaluated the impact of voluntary 24-h, two-bottle choice home-cage alcohol drinking on the prefrontal cortex and amygdala neuroproteome in C57BL/6J mice and found a striking association between alcohol drinking and AD-like pathology. Bioinformatics identified the AD-associated proteins MAPT (Tau), amyloid beta precursor protein (APP), and presenilin-1 (PSEN-1) as the main modulators of alcohol-sensitive protein networks that included AD-related proteins that regulate energy metabolism (ATP5D, HK1, AK1, PGAM1, CKB), cytoskeletal development (BASP1, CAP1, DPYSL2 [CRMP2], ALDOA, TUBA1A, CFL2, ACTG1), cellular/oxidative stress (HSPA5, HSPA8, ENO1, ENO2), and DNA regulation (PURA, YWHAZ). To address the impact of alcohol drinking on AD, studies were conducted using 3xTg-AD mice that express human MAPT, APP, and PSEN-1 transgenes and develop AD-like brain and behavioral pathology. 3xTg-AD and wild-type mice consumed alcohol or saccharin for 4 months. Behavioral tests were administered during a 1-month alcohol-free period. Alcohol intake induced AD-like behavioral pathologies in 3xTg-AD mice including impaired spatial memory in the Morris Water Maze, diminished sensorimotor gating as measured by prepulse inhibition, and exacerbated conditioned fear. Multiplex immunoassay conducted on brain lysates showed that alcohol drinking upregulated primary markers of AD pathology in 3xTg-AD mice: Aβ 42/40 ratio in the lateral entorhinal and prefrontal cortex and total Tau expression in the lateral entorhinal cortex, medial prefrontal cortex, and amygdala at 1-month post alcohol exposure. Immunocytochemistry showed that alcohol use upregulated expression of pTau (Ser199/Ser202) in the hippocampus, which is consistent with late-stage AD. According to the NIA-AA Research Framework, these results suggest that alcohol use is associated with Alzheimer's pathology. Results also showed that alcohol use was associated with a general reduction in Akt/mTOR signaling via several phosphoproteins (IR, IRS1, IGF1R, PTEN, ERK, mTOR, p70S6K, RPS6) in multiple brain regions including hippocampus and entorhinal cortex. Dysregulation of Akt/mTOR phosphoproteins suggests alcohol may target this pathway in AD progression. These results suggest that nondependent alcohol drinking increases the onset and magnitude of AD-like neural and behavioral pathology in 3xTg-AD mice.

Diagnosis and Management of Dementia: Review

Importance

Worldwide, 47 million people live with dementia and, by 2050, the number is expected to increase to 131 million.

Observations

Dementia is an acquired loss of cognition in multiple cognitive domains sufficiently severe to affect social or occupational function. In the United States, Alzheimer disease, one cause of dementia, affects 5.8 million people. Dementia is commonly associated with more than 1 neuropathology, usually Alzheimer disease with cerebrovascular pathology. Diagnosing dementia requires a history evaluating for cognitive decline and impairment in daily activities, with corroboration from a close friend or family member, in addition to a thorough mental status examination by a clinician to delineate impairments in memory, language, attention, visuospatial cognition such as spatial orientation, executive function, and mood. Brief cognitive impairment screening questionnaires can assist in initiating and organizing the cognitive assessment. However, if the assessment is inconclusive (eg, symptoms present, but normal examination findings), neuropsychological testing can help determine whether dementia is present. Physical examination may help identify the etiology of dementia. For example, focal neurologic abnormalities suggest stroke. Brain neuroimaging may demonstrate structural changes including, but not limited to, focal atrophy, infarcts, and tumor, that may not be identified on physical examination. Additional evaluation with cerebrospinal fluid assays or genetic testing may be considered in atypical dementia cases, such as age of onset younger than 65 years, rapid symptom onset, and/or impairment in multiple cognitive domains but not episodic memory. For treatment, patients may benefit from nonpharmacologic approaches, including cognitively engaging activities such as reading, physical exercise such as walking, and socialization such as family gatherings. Pharmacologic approaches can provide modest symptomatic relief. For Alzheimer disease, this includes an acetylcholinesterase inhibitor such as donepezil for mild to severe dementia, and memantine (used alone or as an add-on therapy) for moderate to severe dementia. Rivastigmine can be used to treat symptomatic Parkinson disease dementia.

Conclusions and Relevance

Alzheimer disease currently affects 5.8 million persons in the United States and is a common cause of dementia, which is usually accompanied by other neuropathology, often cerebrovascular disease such as brain infarcts. Causes of dementia can be diagnosed by medical history, cognitive and physical examination, laboratory testing, and brain imaging. Management should include both nonpharmacologic and pharmacologic approaches, although efficacy of available treatments remains limited.