Prevalence of mild behavioural impairment and its association with cognitive and functional impairment in normal cognition, mild cognitive impairment, and mild Alzheimer's dementia

BACKGROUND

Mild behavioural impairment (MBI) is an emergent and persistent neuropsychiatric symptom (NPS) in subjects aged 50 and older who are at risk for cognitive decline. We examined the prevalence of MBI across the spectrum from cognitively normal (CN), mild cognitive impairment (MCI), to dementia, and further investigated the association between the MBI domain and cognitive and functional impairment.

METHOD

MBI was assessed in 2337 elderly patients in the Alzheimer's Disease Neuroimaging Initiative database (mean age, 73.04 years; 52.8% male). Among the subjects, 868 (37.1%) had normal cognition, 1066 (45.6%) had MCI, and 403 (17.2%) had mild Alzheimer's dementia (AD). MBI was evaluated in accordance with the Alzheimer's Association International Society to Advance Alzheimer's Research and Treatment diagnostic criteria for MBI, utilising the Neuropsychiatric Inventory. We compared the prevalence of the MBI domain with CN using multinominal logistic regression analysis and further quantified the magnitude of the association between MCI/AD and the MBI domains by calculating the population attributable risk (PAR). We assessed the association between the MBI domains and cognitive and functional impairment using simultaneous linear regression analysis.

RESULTS

The most common MBI domains in each diagnostic group were affective dysregulation followed by impulse dyscontrol, decreased motivation, social inappropriateness, and abnormal perception or thought content. The PARs for MBI domains in subjects with MCI or AD were respectively: 16.60% and 24.34% for affective dysregulation; 3.72% and 18.06% for impulse dyscontrol; 4.78% and 14.13% for decreased motivation, 1.91% and 2.29% for social inappropriateness; and 0.68% and 3.85% for abnormal perception or thought content. All MBI domains except for social inappropriateness were significantly associated with a higher 11-item Alzheimer's Disease Assessment Scale-Cognitive Subscale total score. All MBI domains were significantly associated with a higher Functional Activities Questionnaire total score.

CONCLUSION

Our findings show that MBI is highly prevalent across subjects with CN, MCI, and AD and is associated with cognitive and functional decline. MBI could be a crucial clinical phenotype relevant to the risk of cognitive and functional impairment, and provides a useful dimension pertinent to diagnostic approaches.

2024 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including prevalence and incidence, mortality and morbidity, use and costs of care and the ramifications of AD for family caregivers, the dementia workforce and society. The Special Report discusses the larger health care system for older adults with cognitive issues, focusing on the role of caregivers and non-physician health care professionals. An estimated 6.9 million Americans age 65 and older are living with Alzheimer's dementia today. This number could grow to 13.8 million by 2060, barring the development of medical breakthroughs to prevent or cure AD. Official AD death certificates recorded 119,399 deaths from AD in 2021. In 2020 and 2021, when COVID-19 entered the ranks of the top ten causes of death, Alzheimer's was the seventh-leading cause of death in the United States. Official counts for more recent years are still being compiled. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2021, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 140%. More than 11 million family members and other unpaid caregivers provided an estimated 18.4 billion hours of care to people with Alzheimer's or other dementias in 2023. These figures reflect a decline in the number of caregivers compared with a decade earlier, as well as an increase in the amount of care provided by each remaining caregiver. Unpaid dementia caregiving was valued at $346.6 billion in 2023. Its costs, however, extend to unpaid caregivers' increased risk for emotional distress and negative mental and physical health outcomes. Members of the paid health care and broader community-based workforce are involved in diagnosing, treating and caring for people with dementia. However, the United States faces growing shortages across different segments of the dementia care workforce due to a combination of factors, including the absolute increase in the number of people living with dementia. Therefore, targeted programs and care delivery models will be needed to attract, better train and effectively deploy health care and community-based workers to provide dementia care. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are almost three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 22 times as great. Total payments in 2024 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $360 billion. The Special Report investigates how caregivers of older adults with cognitive issues interact with the health care system and examines the role non-physician health care professionals play in facilitating clinical care and access to community-based services and supports. It includes surveys of caregivers and health care workers, focusing on their experiences, challenges, awareness and perceptions of dementia care navigation.

Association of Parkinson's disease to Parkinson's plus syndromes, Lewy body dementia, and Alzheimer's dementia

Background

Parkinson's disease (PD) is a condition that affects movement and is usually seen in those over the age of 50. It is caused by the death of dopaminergic neurons, particularly in the substantia nigra. PD has shifted from being perceived as an uncommon condition to a significant neurological illness, mostly due to the increasing number of elderly individuals and the impact of environmental factors. Parkinson's plus syndromes, such as progressive supranuclear palsy (PSP), multiple system atrophy (MSA), corticobasal degeneration (CBD), and vascular Parkinsonism (VaP), provide difficulties in distinguishing them clinically from PD since they have similar characteristics.

Methodology

A thorough examination was performed utilizing the PubMed, Medline, Scopus, and Web of Science databases. The search utilized specific keywords like "Parkinson's disease," "Parkinson's plus syndrome," "Lewy body dementia," "Alzheimer's dementia," "progressive supranuclear palsy," and "multiple system atrophy." The selection criteria were aimed at English-language literature, with a particular focus on examining the connection between PD and associated disorders or dementias.

Results and Discussion

Parkinson's plus syndromes, such as PSP, MSA, CBD, and VaP, exhibit unique clinical characteristics, imaging results, and diverse reactions to levodopa. This makes it difficult to distinguish them from PD. LBD is characterized by Lewy bodies containing α-synuclein, which leads to both motor and cognitive deficits. PD and Alzheimer's disease (AD) exhibit a complex interaction, including common pathogenic processes, genetic predispositions, and clinical characteristics of dementia.

Conclusion

The interrelatedness of PD, Parkinson's plus syndromes, LBD, and AD highlights the significance of comprehending shared disease-causing processes. Aberrant protein clumping, impaired functioning of mitochondria, increased oxidative stress, and inflammation in the brain are common factors which can be addressed for specific treatments. More research is essential for understanding complicated connections and developing effective therapies for these sophisticated neurological illnesses.

Diabetes, antidiabetic medications and risk of dementia: A systematic umbrella review and meta-analysis

AIMS

The objective of this umbrella review and meta-analysis was to evaluate the effect of diabetes on risk of dementia, as well as the mitigating effect of antidiabetic treatments.

MATERIALS AND METHODS

We conducted a systematic umbrella review on diabetes and its treatment, and a meta-analysis focusing on treatment. We searched MEDLINE/PubMed, Embase, PsycINFO, CINAHL and the Cochrane Library for systematic reviews and meta-analyses assessing the risk of cognitive decline/dementia in individuals with diabetes until 2 July 2023. We conducted random-effects meta-analyses to obtain risk ratios and 95% confidence intervals estimating the association of metformin, thiazolidinediones, pioglitazone, dipeptidyl peptidase-4 inhibitors, α-glucosidase inhibitors, meglitinides, insulin, sulphonylureas, glucagon-like peptide-1 receptor agonists (GLP1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) with risk of dementia from cohort/case-control studies. The subgroups analysed included country and world region. Risk of bias was assessed with the AMSTAR tool and Newcastle-Ottawa Scale.

RESULTS

We included 100 reviews and 27 cohort/case-control studies (N = 3 046 661). Metformin, thiazolidinediones, pioglitazone, GLP1RAs and SGLT2is were associated with significant reduction in risk of dementia. When studies examining metformin were divided by country, the only significant effect was for the United States. Moreover, the effect of metformin was significant in Western but not Eastern populations. No significant effect was observed for dipeptidyl peptidase-4 inhibitors, α-glucosidase inhibitors, or insulin, while meglitinides and sulphonylureas were associated with increased risk.

CONCLUSIONS

Metformin, thiazolidinediones, pioglitazone, GLP1RAs and SGLT2is were associated with reduced risk of dementia. More longitudinal studies aimed at determining their relative benefit in different populations should be conducted.

Corrigendum: Causal associations between common musculoskeletal disorders and dementia: a Mendelian randomization study

[This corrects the article DOI: 10.3389/fnagi.2023.1253791.].

Critical analysis of ginkgo preparations: comparison of approved drugs and dietary supplements marketed in Germany

Demographic change is taking place in the population of western industrialized countries, and the population is aging constantly. As a result, the mortality rate of patients due to dementia is rising steadily. To counteract this, the relevance of neuroprotective agents is increasing. Preparations from the medicinal tree species Ginkgo biloba ("gingko") are becoming increasingly popular. In this study, 63 ginkgo preparations marketed in Germany were analyzed. The following data were collected from the package inserts of the preparations: Country of manufacture, approval as a drug, compliance to target values of flavone glycosides, compliance to target values of terpene lactones, compliance to target values of ginkgolic acids, dosage per unit in milligrams (mg), duration of use, interactions with other drugs, contraindications, adverse effects and daily defined dose costs. In the next step, these data were compared in the following form: Total preparations versus preparations with drug approval versus dietary supplements. Almost without exception, the results indicate a pharmaceutical reliability of the preparations with drug approval and a dubious reliability of the preparations marketed as dietary supplements. Thus, ginkgo preparations marketed as dietary supplements appear to have an economic rather than a medical focus. We discuss the evidence of efficacy, and other criteria mentioned above, to evaluate the adequacy of the costs for the statutory health insurance that pay for preparations with drug approval in Germany. From the analysis of our results it is very doubtful that ginkgo biloba extract preparations of the food industry have any health benefit. It must be evaluated whether prohibition of selling ginkgo biloba extract as a dietary supplement is an option.

Gait and/or balance disturbances associated with Alzheimer's dementia among older adults with amnestic mild cognitive impairment: A longitudinal observational study

AIMS

To explore whether gait and/or balance disturbances are associated with the onset of Alzheimer's dementia (AD) among older adults with amnestic mild cognitive impairment (MCI).

DESIGN

This study employed a longitudinal retrospective cohort design.

METHODS

We obtained data from the National Alzheimer's Coordinating Center's Uniform Data Set collected from 35 National Institute on Aging Alzheimer's Disease Research Centers between September 2005 and December 2021. The mean age of participants (n = 2692) was 74.5 years with women making up 47.2% of the sample. Risk of incident AD according to baseline gait and/or balance disturbances as measured using the Postural Instability and Gait Disturbance Score, a subscale of the Unified Parkinson's Disease Rating Scale Motor Score, was examined by the Cox proportional hazards regression models adjusting for baseline demographics, medical conditions and study sites. The mean follow-up duration was 4.0 years.

RESULTS

Among all the participants, the presence or the severity of gait and/or balance disturbances was associated with an increased risk of AD. The presence or the severity of gait and/or balance disturbances was associated with a higher risk of Alzheimer's dementia among the subgroups of female and male participants.

CONCLUSION

Gait and/or balance disturbances may increase the risk of developing AD, regardless of sex.

IMPACT

Gait and/or balance disturbances among community-dwelling older adults with amnestic MCI may need to be frequently assessed by nurses to identify potential risk factors for cognitive decline.

NO PATIENT OR PUBLIC CONTRIBUTION

Given the secondary analysis, patients, service users, caregivers or members of the public were not directly involved in this study.

Association between serum lipid levels and lower-extremity functions in older adults with and without Alzheimer's dementia in South Korea: A cross-sectional analysis

PURPOSE

Older adults with Alzheimer's dementia (AD) experience lower-extremity dysfunction. High serum lipid levels are a risk factor for AD. We investigated the association between serum lipid levels and lower-extremity function in older individuals with and without AD.

METHODS

In this cross-sectional study, we enrolled 33,185 senior citizens (aged 66 years) who participated in the National Geriatric Screening Program, sampled from the Korean National Health Insurance Service-National Health Screening Cohort Database, between 2009 and 2015. Participants were dichotomized into 1) an AD group comprising individuals with the International Classification of Diseases, Tenth Revision, diagnostic codes F00, F00.0-F00.9, and G30, G30.0-G30.9; and 2) a control group comprising individuals without AD. Differences in the Timed Up and Go and One-Leg Standing results among the three levels (low, moderate, and high) of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol were evaluated between the groups. Logistic regression analysis was performed to estimate the odds of gait disorder considering clinical and lifestyle variables.

RESULTS

In participants with low LDL-C levels, increased LDL-C levels correlated with higher gait speed. In the AD group, balancing time with eyes open (BT-EO) was inversely correlated with TG levels in participants with low TG levels. In the control group, BT-EO was negatively correlated with TC levels in participants with low TC levels.

CONCLUSION

Serum lipid levels were significantly correlated with lower-extremity function in participants with and without AD but not with gait disorder in participants with AD.

The nature of the task stimuli affects graphic perseveration severity: Insights from a single case study

OBJECTIVE

Graphic perseveration in target-cancellation tasks has been frequently described in patients with right brain damage and unilateral spatial neglect. Conversely, among patients with dementia, the spontaneous production of complex graphic perseverations, as well as their triggers and modulating factors, have been poorly understood. Here we describe the case of RM, a patient with Alzheimer's dementia, who produced a rich pattern of complex graphic perseverations at target-cancellation tasks, especially with abstract target stimuli, i.e., lines.

METHOD

We developed an ad-hoc behavioral paradigm to investigate patient RM's performance at two versions of a target-cancellation task: fork-cancellation and line-cancellation. In both versions, RM was asked to cross the blue targets, while crossing a red target was considered a false alarm, as a proxy of incorrect response inhibition capacity. Moreover, we classified the presence and intensity of two other graphic perseverative behaviors, i.e., additional marks and scribble perseveration.

RESULTS

Complex graphic perseverations and false alarms were more frequent in the line-compared to the fork-cancellation trials. Conversely, the semantic nature of the task did not differentially modulate the occurrence of additional marks and scribble perseverations.

CONCLUSIONS

We argue that the breakdown of RM's executive functioning at the semantic-representational level was a prerequisite for such complex graphic perseverations to occur. Furthermore, we provide hints on the potential modulatory effects of stimulus concreteness on the expression of such complex productive behavior.

Evolution of neurodegeneration in patients with normal pressure hydrocephalus: a monocentric follow up study

BACKGROUND

The aim of this study was to examine in patients with idiopathic and neurodegenerative normal pressure hydrocephalus (NPH) if motor and cognitive performance as well as changes in biomarkers in cerebrospinal fluid (CSF) evolve differently.

METHODS

41 patients with a typical clinical and MR-/CT-morphological presentation of NPH divided into an Alzheimer-negative (AD-, n = 25) and an Alzheimer-positive (AD+, n = 16) group according to neurodegenerative biomarkers (S100 protein, neuron-specific enolase, β-amyloid 1-42, Tau protein, phospho-Tau, protein-level and CSF pressure) in CSF. Follow-up of cognitive and gait functions before and after a spinal tap of 40-50 ml CSF of up to 49 months. Clinical, motor, neuropsychological and CSF biomarkers were analyzed using a repeated multifactorial analysis of variance (ANOVA) with post-hoc testing.

RESULTS

Gait and neuropsychological performance and CSF biomarkers evolved differently between the AD- and AD+ patients. In particular, the AD+ patients benefited from the spinal tap regarding short-term memory. In contrast, gait parameters worsened over time in the AD+ patients, although they showed a relevant improvement after the first tap.

CONCLUSIONS

The results substantiate the recently reported association between a tap-responsive NPH and CSF changes of Alzheimer disease. Furthermore, they suggest that the AD changes in CSF manifest in an age-related fashion in AD- patients presenting with NPH.

Predicting age at Alzheimer's dementia onset with the cognitive clock

INTRODUCTION

Intervention of Alzheimer's dementia hinges on early diagnosis and advanced planning. This work utilizes the cognitive clock, a novel indicator of brain health, to develop a dementia prediction model that can be easily applied in broad settings.

METHODS

Data came from over 3000 community-dwelling older adults. Cognitive age was estimated by aligning Mini-Mental State Examination (MMSE) scores to a clock that represents the typical cognitive aging profile. We identified a mean cognitive age at Alzheimer's dementia onset and predicted the corresponding chronological age at person-specific level.

RESULTS

The mean chronological age at baseline was 78 years. A total of 881 (28%) participants developed Alzheimer's dementia. The mean cognitive age at onset was 91 years. The predicted chronological age at onset had a mean (standard deviation) of 87.6 (6.7) years. The model's prediction accuracy was supported by multiple testing statistics.

DISCUSSION

Our model offers an easy-to-use tool for predicting person-specific age at Alzheimer's dementia onset.

The association of MIND diet with cognitive resilience to neuropathologies

INTRODUCTION

Cognitive resilience (CR) can be defined as the continuum of better through worse than expected cognition, given the degree of neuropathology. The relation of healthy diet patterns to CR remains to be elucidated.

METHODS

Using longitudinal cognitive data and post mortem neuropathology from 578 deceased older adults, we examined associations between the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet at baseline and two standardized CR measures reflecting higher cognitive levels over time (CRLevel ¯ $_{\overline {{\rm{Level}}}} $ ), and slower decline (CRSlope ), than expected given neuropathology.

RESULTS

Compared to individuals in the lowest tertile of MIND score, those in the top tertile had higher CRLevel ¯ $_{\overline {{\rm{Level}}}} $ (mean difference [MD] = 0.34; 95% confidence interval [CI] = 0.14, 0.55) and CRSlope (MD = 0.27; 95% CI = 0.05, 0.48), after multivariable adjustment. Overall MIND score was more strongly related to CR than the individual food components.

DISCUSSION

The MIND diet is associated with both higher cognition and slower rates of cognitive decline, after controlling for neuropathology, indicating the MIND diet may be important to cognitive resilience.

Case report: Mixed dementia associated with autoantibodies targeting the vesicular glutamate transporter 2

Background

Autoantibodies against the vesicular glutamate transporter type 2 (VGlut2) can trigger impaired synaptic signaling and are described here for the first time in association with mixed dementia.

Methods

We report on a 71-year-old female patient with a dementing syndrome who underwent a thorough dementia diagnosis including neuropsychological testing, magnetic resonance imaging (MRI), ¹⁸F-fluorodesoxyglucose positron emission tomography (FDG-PET), and a spinal tap to search for neural autoantibodies.

Results

Our patient exhibited mixed dementia. Her CSF revealed elevated ptau 181 protein and a reduced Aß42/40 ratio indicating Alzheimer's disease (AD) pathology. In addition, neuropsychological testing showed a profile consistent with AD with impaired memory, reduced semantic word fluency, naming disorder, and impaired visuoconstructive skills. Nevertheless, in-depth neuropsychological testing also revealed marked psychomotor slowing and visuospatial perceptual impairments that are more indicative of the presence of DLB. Overall, her dementia is more likely of mixed pathology. In addition, we repeatedly detected VGlut2 autoantibodies in her serum.

Conclusion

To the best of our knowledge, this report is the first to describe mixed dementia associated with VGlut2 autoantibodies.

The development of the Cognitive Assessment for Tagalog Speakers (CATS): A culturally and linguistically tailored test battery for Filipino Americans

INTRODUCTION

Filipino Americans are one of the largest Asian American and Pacific Islander (AAPI) populations in the United States (US). Previous studies suggest that Filipino Americans have one of the highest incidence rates of Alzheimer's disease and related dementias (ADRD) among AAPI subgroups. Despite the expected increase in Filipino Americans with ADRD, no studies to-date have validated neuropsychological measures in the United States for speakers of Tagalog, a major language spoken by Filipino Americans. A significant barrier to dementia care and diagnosis is the lack of linguistically and socioculturally appropriate cognitive tasks for Tagalog speakers. To address this need, we developed and piloted the Cognitive Assessment for Tagalog Speakers (CATS), the first neuropsychological battery for the detection of ADRD in Filipino American Tagalog speakers.

METHODS

Based on evidence-based neuropsychological batteries, we adapted and constructed de novo tasks to measure performance across 4 main cognitive domains: visual/verbal memory, visuospatial functioning, speech and language, and frontal/executive functioning. Tasks were developed with a team of bilingual English/Tagalog, bicultural Filipino American/Canadian experts, including a neurologist, speech-language pathologist, linguist, and neuropsychologist. We recruited Tagalog-speaking participants of age 50+ through social media advertisements and recruitment registries for this cross-sectional study. We present the CATS design and protocol.

RESULTS

To-date, the CATS battery has been administered to 26 healthy control participants (age 64.5 ± 7.8 years, 18F/8 M) at an academic institution in Northern California, United States. The development and administration of the CATS battery demonstrated its feasibility but also highlighted the need to consider the effects of bilingualism, language typology, and cultural factors in result interpretation.

DISCUSSION

The CATS battery provides a mechanism for cognitive assessment of Filipino Americans, a population that has been underrepresented in ADRD research. As we move toward the treatment and cure of ADRD, linguistically and socioculturally appropriate cognitive tests become even more important for equitable care.

Externalizing traits: Shared causalities for COVID-19 and Alzheimer's dementia using Mendelian randomization analysis

Externalizing traits have been related with the outcomes of coronavirus disease 2019 (COVID-19) and Alzheimer's dementia (AD); however, whether these associations are causal remains unknown. We used the two-sample Mendelian randomization (MR) approach with more than 200 single-nucleotide polymorphisms (SNPs) for externalizing traits to explore the causal associations of externalizing traits with the risk of COVID-19 (infected COVID-19, hospitalized COVID-19, and severe COVID-19) or AD based on the summary data. The inverse variance-weighted method (IVW) was used to estimate the main effect, followed by several sensitivity analyses. IVW analysis showed significant associations of externalizing traits with COVID-19 infection (odds ratio [OR] = 1.456, 95% confidence interval [95% CI] = 1.224-1.731), hospitalized COVID-19 (OR = 1.970, 95% CI = 1.374-2.826), and AD (OR = 1.077, 95% CI = 1.037-1.119). The results were consistent using weighted median (WM), penalized weighted median (PWM), MR-robust adjusted profile score (MR-RAPS), and leave-one-out sensitivity analyses. Our findings assist in exploring the causal effect of externalizing traits on the pathophysiology of infection and severe infection of COVID-19 and AD. Furthermore, our study provides evidence that shared externalizing traits underpin the two diseases.

One-year Medicare costs associated with delirium in older hospitalized patients with and without Alzheimer's disease dementia and related disorders

INTRODUCTION

One-year health-care costs associated with delirium in older hospitalized patients with and without Alzheimer's disease and related dementias (ADRD) have not been examined previously.

METHODS

Medicare costs were determined prospectively at discharge, and at 30, 90, and 365 days in a cohort (n = 311) of older adults after hospital admission.

RESULTS

Seventy-six (24%) patients had ADRD and were more likely to develop delirium (51% vs. 24%, P < 0.001) and die within 1 year (38% vs. 21%, P = 0.002). In ADRD patients with versus without delirium, adjusted mean difference in costs associated with delirium were $34,828; most of the excess costs were incurred between 90 and 365 days (P = 0.03). In non-ADRD patients, delirium was associated with increased costs at all timepoints. Excess costs associated with delirium in ADRD patients increased progressively over 1 year, whereas in non-ADRD patients the increase was consistent across time periods.

DISCUSSION

Our findings highlight the complexity of health-care costs for ADRD patients who develop delirium, a potentially preventable source of expenditures.

HIGHLIGHTS

Novel examination of health-care costs of delirium in persons with and without Alzheimer's disease and related dementias (ADRD). Increased 1-year costs of $34,828 in ADRD patients with delirium (vs. without). Increased costs for delirium in ADRD occur later during the 365-day study period. For ADRD patients, cost differences between those with and without delirium increased over 1 year. For non-ADRD patients, the parallel cost differences were consistent over time.

Vascular dementia subtypes, pathophysiology, genetics, neuroimaging, biomarkers, and treatment updates along with its association with Alzheimer's dementia and diabetes mellitus

Dementia is a chronic progressive cognitive decline illness that results in functional impairment. Vascular dementia (VaD), second only to Alzheimer's disease (AD), is one of the most prevalent forms of dementia in the elderly (aged over 65 years), with a varied presentation and unpredictable disease development caused by cerebrovascular or cardiovascular illness. To get a better understanding of the changes occurring in the brain and to drive therapy efforts, new biomarkers for early and precise diagnosis of AD and VaD are required. In this review, Firstly, we describe the subtypes of vascular dementia, their clinical features, pathogenesis, genetics implemented, and their associated neuroimaging and biomarkers, while describing extensively the recent biomarkers discovered in the literature. Secondly, we describe some of the well-documented and other less-defined risk factors and their association and pathophysiology in relation to vascular dementia. Finally, we follow recent updates in the management of vascular dementia along with its association and differentiation from Alzheimer's disease. The aim of this review is to gather the scattered updates and the most recent changes in blood, CSF, and neuroimaging biomarkers related to the multiple subtypes of vascular dementia along with its association with Alzheimer's dementia and diabetes mellitus.

Particulate matter exposure from motorized traffic and risk of conversion from mild cognitive impairment to dementia: An Italian prospective cohort study

BACKGROUND

Based on epidemiologic and laboratory studies, exposure to air pollutants has been linked to many adverse health effects including a higher risk of dementia. In this study, we aimed to evaluate the effect of long-term exposure to outdoor air pollution on risk of conversion to dementia in a cohort of subjects with mild cognitive impairment (MCI).

METHODS

We recruited 53 Italian subjects newly-diagnosed with MCI. Within a geographical information system, we assessed recent outdoor air pollutant exposure, by modeling air levels of particulate matter with equivalent aerodynamic diameter ≤10 μm (PM₁₀) from motorized traffic at participants' residence. We investigated the relation of PM₁₀ concentrations to subsequent conversion from MCI to any type of dementia. Using a Cox-proportional hazards model combined with a restricted cubic spline model, we computed the hazard ratio (HR) of dementia with its 95% confidence interval (CI) according to increasing PM₁₀ exposure, adjusting for sex, age, and educational attainment.

RESULTS

During a median follow up of 47.3 months, 34 participants developed dementia, in 26 cases diagnosed as Alzheimer's dementia. In non-linear restricted spline regression analysis, mean and maximum annual PM₁₀ levels positively correlated with cerebrospinal fluid total and phosphorylated tau proteins concentrations, while they were inversely associated with β-amyloid. Concerning the risk of dementia, we found a positive association starting from above 10 μg/m³ for mean PM₁₀ levels and above 35 μg/m³ for maximum PM₁₀ levels. Specific estimates for Alzheimer's dementia were substantially similar. Adding other potential confounders to the multivariable model or removing early cases of dementia onset during the follow-up had little effect on the estimates.

CONCLUSIONS

Our findings suggest that exposure to outdoor air pollutants, PM₁₀ in particular, may non-linearly increase conversion from MCI to dementia above a certain ambient air concentration.

An intracerebroventricular injection of AΒ (1-42) modifies temporal profiles of spatial memory performance and oxidative status in the temporal cortex rat

Alzheimer's dementia (AD) is a neurodegenerative disorder that causes memory loss and dementia in older adults. Intracellular accumulation of Aβ causes an imbalance in the oxidative status and cognitive dysfunctions. Besides oxidative stress and loss of memory, Alzheimer's patients show dysfunction of the circadian rhythms. The objective of this work was to evaluate the consequences of an intracerebroventricular injection of Aβ (1-42) on temporal patterns of cognitive performance, as well as on lipid peroxidation, protein oxidation and total antioxidant capacity levels, in the rat temporal cortex. Holtzman male rats from control and Aβ-injected groups were used in this study. We found that MDA, protein carbonyls and total antioxidant capacity levels displayed day-night oscillations in the rat temporal cortex and spatial memory performance also varied rhythmically. An intracerebroventricular injection of Aβ (1-42) modified temporal patterns of cognitive performance as well as daily profiles of parameters of oxidative stress. Thus, elevated levels of Aβ aggregates induces alterations in daily rhythmicity of parameters of oxidative stress and, consequently, would affect cellular clock activity, affecting the spatial memory performance in the AD.

Abnormal white matter changes in Alzheimer's disease based on diffusion tensor imaging: A systematic review

Alzheimer's disease (AD) is a degenerative neurological disease in elderly individuals. Subjective cognitive decline (SCD), mild cognitive impairment (MCI) and further development to dementia (d-AD) are considered to be major stages of the progressive pathological development of AD. Diffusion tensor imaging (DTI), one of the most important modalities of MRI, can describe the microstructure of white matter through its tensor model. It is widely used in understanding the central nervous system mechanism and finding appropriate potential biomarkers for the early stages of AD. Based on the multilevel analysis methods of DTI (voxelwise, fiberwise and networkwise), we summarized that AD patients mainly showed extensive microstructural damage, structural disconnection and topological abnormalities in the corpus callosum, fornix, and medial temporal lobe, including the hippocampus and cingulum. The diffusion features and structural connectomics of specific regions can provide information for the early assisted recognition of AD. The classification accuracy of SCD and normal controls can reach 92.68% at present. And due to the further changes of brain structure and function, the classification accuracy of MCI, d-AD and normal controls can reach more than 97%. Finally, we summarized the limitations of current DTI-based AD research and propose possible future research directions.

2023 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease, including prevalence and incidence, mortality and morbidity, use and costs of care, and the overall impact on family caregivers, the dementia workforce and society. The Special Report examines the patient journey from awareness of cognitive changes to potential treatment with drugs that change the underlying biology of Alzheimer's. An estimated 6.7 million Americans age 65 and older are living with Alzheimer's dementia today. This number could grow to 13.8 million by 2060 barring the development of medical breakthroughs to prevent, slow or cure AD. Official death certificates recorded 121,499 deaths from AD in 2019, and Alzheimer's disease was officially listed as the sixth-leading cause of death in the United States. In 2020 and 2021, when COVID-19 entered the ranks of the top ten causes of death, Alzheimer's was the seventh-leading cause of death. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2019, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 145%. This trajectory of deaths from AD was likely exacerbated by the COVID-19 pandemic in 2020 and 2021. More than 11 million family members and other unpaid caregivers provided an estimated 18 billion hours of care to people with Alzheimer's or other dementias in 2022. These figures reflect a decline in the number of caregivers compared with a decade earlier, as well as an increase in the amount of care provided by each remaining caregiver. Unpaid dementia caregiving was valued at $339.5 billion in 2022. Its costs, however, extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes - costs that have been aggravated by COVID-19. Members of the paid health care workforce are involved in diagnosing, treating and caring for people with dementia. In recent years, however, a shortage of such workers has developed in the United States. This shortage - brought about, in part, by COVID-19 - has occurred at a time when more members of the dementia care workforce are needed. Therefore, programs will be needed to attract workers and better train health care teams. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are almost three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 22 times as great. Total payments in 2023 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $345 billion. The Special Report examines whether there will be sufficient numbers of physician specialists to provide Alzheimer's care and treatment now that two drugs are available that change the underlying biology of Alzheimer's disease.

Natural IgG antibodies to β amyloid are decreased in patients with Parkinson's disease

Natural antibodies (nAbs) against aggregation-prone proteins have been found in healthy normal subjects. These proteins likely have a pathogenetic role in neurodegenerative diseases of ageing. They include the amyloid β (Aβ) protein which may play an important role in Alzheimer's dementia (AD), and α-synuclein, a major determinant of Parkinson's disease (PD). We measured nAbs to Aβ in a group of Italian patients with AD, vascular dementia, non-demented PD patients and healthy elderly controls. We found that Aβ antibody levels in AD were similar to age- and sex-matched controls, but contrary to our expectations, they were significantly reduced in PD. This may identify patients that could be more prone to amyloid aggregation.

Standardization and Validation of the Flash Visual Evoked Potential-P2 Conversion Scores in the Diagnosis of Amnestic Mild Cognitive Impairment and Alzheimer's Dementia

Amnestic mild cognitive impairment (aMCI), which is characterized by normal daily activity, but a significant decline in episodic memory, is now widely accepted as a risk factor for the development of Alzheimer's dementia (AD). Research suggests that many of the same neuropathological changes associated with AD also occur in patients diagnosed with aMCI. A recent review of the literature revealed that the latency of the flash visual-evoked potential-P2 (FVEP-P2) may possess pathognomonic information that may assist in the early detection of aMCI. While standards exist for the recording of FVEP-P2, individual clinics often use recording parameters that may differ, resulting in latencies that may not generalize beyond the clinic that produced them. The present article illustrates the process by which the FVEP-P2 latency can be standardized across clinics using FVEP-P2 Conversion Scores. We then demonstrate the diagnostic accuracy of the newly developed scores. Method: In the present investigation, we used the previously unpublished data containing the FVEP-P2 latencies of 45 AD and 60 controls. Result: We were able to demonstrate the process by which individual clinics may first standardize FVEP-P2 latencies and then examine patient performance using FVEP-P2 Conversion Scores, providing clinicians with a richer context from which to examine the patient performance. Conclusion: Consistent with the findings of previous research, the findings of the present investigation support the use of the FVEP-P2 Conversion Scores in the diagnosis of AD. Future directions, including the modification of recording parameters associated with the FVEP-P2, are also discussed.

Association of impaired kidney function with dementia and brain pathologies: A community-based cohort study

INTRODUCTION

The relationship between impaired kidney function (KF), dementia, and brain pathologies remains unclear.

METHODS

A total of 1354 dementia- and kidney disease-free participants including 895 with normal and 459 with impaired KF were followed from 2002 until 2020 (median [interquartile range]: 5 [2-9]) to detect incident dementia. KF was assessed at baseline and categorized as normal or impaired. Over the follow-up, 453 participants died and underwent autopsies for neuropathological assessment.

RESULTS

Compared to those with normal KF, the hazard ratios (95% confidence intervals [CIs]) of those with impaired KF was 1.48 (1.15, 1.90)/1.44 (1.10, 1.88) for dementia/Alzheimer's dementia. Furthermore, impaired KF was related to a significantly higher burden of cerebral amyloid angiopathy (CAA; odds ratio = 1.96, 95% CI: 1.17, 3.30), but not to other brain pathologies.

DISCUSSION

Impaired KF is associated with an increased risk of dementia and Alzheimer's dementia. CAA may underlie, in part, this association.

HIGHLIGHTS

Impaired kidney function (KF) was associated with higher dementia and Alzheimer's dementia risk. Impaired KF anticipated dementia and Alzheimer's dementia onset by more than 1.5 years. Impaired KF was significantly related to a higher burden of cerebral amyloid angiopathy (CAA) but not to other brain pathologies.

Quantifying longitudinal cognitive resilience to Alzheimer's disease and other neuropathologies

INTRODUCTION

Cognitive resilience (CR) has been defined as the continuum of better (or worse) than expected cognition, given the degree of neuropathology. To quantify this concept, existing approaches focus on either cognitive level at a single time point or slopes of cognitive decline.

METHODS

In a prospective study of 1215 participants, we created a continuous measure of CR defined as the mean of differences between estimated person-specific and marginal cognitive levels over time, after accounting for neuropathologies.

RESULTS

Neuroticism and depressive symptoms were associated with all CR measures (P-values < .012); as expected, cognitive activity and education were only associated with the cognitive-level approaches (P-values < .0002). However, compared with the existing CR measures focusing on a single measure or slopes of cognition, our new measure yielded stronger relations with risk factors.

DISCUSSION

Defining CR based on the longitudinal differences between person-specific and marginal cognitive levels is a novel and complementary way to quantify CR.

Risk of Alzheimer's disease and related dementia by sex and race/ethnicity: The Multiethnic Cohort Study

INTRODUCTION

Data are limited for comparison of sex- and race/ethnicity-specific risks of Alzheimer's disease and related dementia (ADRD).

METHODS

In the population-based Multiethnic Cohort, we estimated the age-standardized diagnostic incidence rate (ASDIR) and relative risk of late-onset ADRD (n = 16,410) among 105,796 participants based on Medicare claims (1999-2014) by sex and race/ethnicity.

RESULTS

The ASDIR for ADRD was higher for women (17.0 per 1000 person-years) than for men (15.3) and varied across African Americans (22.9 in women, 21.5 in men), Native Hawaiians (19.3, 19.4), Latinos (16.8, 14.7), Whites (16.4, 15.5), Japanese Americans (14.8, 13.8), and Filipinos (12.5, 9.7). Similar risk patterns were observed for AD. Adjustment for education and cardiometabolic diseases attenuated the differences. Accounting for deaths from competing causes increased the sex difference, while reducing the racial/ethnic differences. Less racial/ethnic disparity was detected among apolipoprotein E (APOE) e4 carriers.

DISCUSSION

More research is needed to understand the sex and racial/ethnic differences in ADRD.

2022 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including incidence and prevalence, mortality and morbidity, use and costs of care, and the overall impact on family caregivers, the dementia workforce and society. The Special Report discusses consumers' and primary care physicians' perspectives on awareness, diagnosis and treatment of mild cognitive impairment (MCI), including MCI due to Alzheimer's disease. An estimated 6.5 million Americans age 65 and older are living with Alzheimer's dementia today. This number could grow to 13.8 million by 2060 barring the development of medical breakthroughs to prevent, slow or cure AD. Official death certificates recorded 121,499 deaths from AD in 2019, the latest year for which data are available. Alzheimer's disease was officially listed as the sixth-leading cause of death in the United States in 2019 and the seventh-leading cause of death in 2020 and 2021, when COVID-19 entered the ranks of the top ten causes of death. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2019, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 145%. More than 11 million family members and other unpaid caregivers provided an estimated 16 billion hours of care to people with Alzheimer's or other dementias in 2021. These figures reflect a decline in the number of caregivers compared with a decade earlier, as well as an increase in the amount of care provided by each remaining caregiver. Unpaid dementia caregiving was valued at $271.6 billion in 2021. Its costs, however, extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes - costs that have been aggravated by COVID-19. Members of the dementia care workforce have also been affected by COVID-19. As essential care workers, some have opted to change jobs to protect their own health and the health of their families. However, this occurs at a time when more members of the dementia care workforce are needed. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are almost three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 22 times as great. Total payments in 2022 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $321 billion. A recent survey commissioned by the Alzheimer's Association revealed several barriers to consumers' understanding of MCI. The survey showed low awareness of MCI among Americans, a reluctance among Americans to see their doctor after noticing MCI symptoms, and persistent challenges for primary care physicians in diagnosing MCI. Survey results indicate the need to improve MCI awareness and diagnosis, especially in underserved communities, and to encourage greater participation in MCI-related clinical trials.

An Overview of Combination Treatment with Citicoline in Dementia

INTRODUCTION

The present article reports an overview of the studies about combination treatment with citicoline of Alzheimer's (AD) and mixed dementia (MD).

METHODS

A Medline search was carried out by using the keywords Alzheimer's dementia, mixed dementia, older people, treatment with citicoline, memantine, and acetylcholinesterase inhibitors (AchEIs).

RESULTS

Six studies were found to match the combination treatment of citicoline with AcheIs and/or memantine. The CITIRIVAD and CITICHOLINAGE studies were the first to report the potential benefits of adding citicoline to acetylcholinesterase inhibitors (AchEIs). Then, we added citicoline to memantine in the CITIMEM study, and finally, we demonstrated benefits in terms of delay in cognitive worsening with the triple therapy (citicoline + AchEIs + memantine). Other authors also reinforced our hypothesis through two further studies.

CONCLUSIONS

Open, prospective studies are advised to confirm the utility of combination therapy with citicoline for the treatment of AD and MD.

Comparison of the Mini-Mental State Examination and Computerized Brief Cognitive Screening Test as Cognitive Screening Tools in Patients with Mild Cognitive Impairment

BACKGROUND

The aim of this study was to establish the validity and reliability of the Computerized Brief Cognitive Screening Test (CBCog) for early detection of cognitive impairment.

METHOD

One hundred and sixty participants, including community-dwelling and out-patient volunteers (both men and women) aged ≥ 65 years, were enrolled in the study. All participants were screened using the CBCog and Mini-Mental State Examination (MMSE). The internal consistency of the CBCog was analyzed using Cronbach's α test. Areas under the curves (AUCs) of receiver operating characteristic analyses were used to test the predictive accuracy of the CBCog in detecting mild cognitive impairment (MCI) in order to set an appropriate cutoff point.

RESULTS

The CBCog scores were positively correlated with the MMSE scores of patients with MCI-related dementia (r = 0.678, P < .001). The internal consistency of the CBCog (Cronbach's α) was 0.706. It was found that the CBCog with a cutoff point of 19/20 had a sensitivity of 97.5% and a specificity of 53.7% for the diagnosis of MCI with education level ≥ 6 years. The AUC of the CBCog for discriminating the normal control elderly from patients with MCI (AUC = 0.827, P < 0.001) was larger than that of the MMSE for discriminating the normal control elderly from patients with MCI (AUC= 0.819, P < .001).

CONCLUSION

The CBCog demonstrated to have sufficient validity and reliability to evaluate mild cognitive impairment, especially in highly educated elderly people.

Determinants of Caregiver Burden in Early-Onset Dementia

Introduction

Caregivers of patients with early-onset dementia (EOD) experience high levels of burden, which is known to be affected by caregivers' psychological features as well as by patients' and caregivers' demographical and social variables. Although potential clinical, demographical, and social determinants have been separately examined, it is not known how they reciprocally interact.

Methods

Ninety-two consecutive patient-caregiver dyads were recruited from the Cognitive Neurology Clinics of Modena, Northern Italy. Caregivers were asked to fill in questionnaires regarding their burden, psychological distress, and family economic status. Data were analyzed with multivariable regression models and then entered in a mediation model.

Results

Caregiver burden was positively related to female caregiver sex, spousal relationship to the patient, severity of patient's behavioral symptoms, diagnostic delay, and financial distress of the family. It was negatively related to disease duration, patient's education, region of birth, caregiver age, number of caregiver's days off work, number of offspring, and caregiver perception of patient's quality of life. While the effect of caregiver age, diagnostic delay, and of proxies of family or social network directly impacted on caregiver's burden, the effect of patient's disease duration, being a wife caregiver, financial distress, and number of caregiver's days off work was entirely mediated by the level of caregiver psychological distress.

Conclusions

Both direct actions (such as increasing social networks and shortening diagnostic delay) and indirect actions aimed at reducing psychological distress (such as increasing the number of caregiver's days off work and financial support) should be planned to reduce caregiver's burden.

Longitudinal Cognitive Profiles by Anxiety and Depressive Symptoms in American Older Adults With Subjective Cognitive Decline

PURPOSE

The objective of this study was to determine how anxiety and/or depressive symptoms differentially affect specific cognitive domains over time in persons with subjective cognitive decline (SCD).

DESIGN

A longitudinal, observational study was conducted using data from the National Alzheimer's Coordinating Center-Uniform Data Set. Mean follow-up was 4.1 ± 2.4 years.

METHODS

Using information from a total of 1401 participants (age 74.0 ± 8.2 years), linear mixed-effects regression models were used to assess longitudinal changes in global cognition, episodic memory, attention, language, and executive function by baseline psychological (anxiety [A] and/or depressive [D]) symptoms in individuals with SCD. Reference was the group having no symptoms (A-/D-).

FINDINGS

The A+/D- group was not associated with any cognitive changes. The A-/D+ group was associated with a greater decline in episodic memory and executive function. The A+/D+ group had a greater decline in attention. Changes in global cognition and language were not predicted by any psychological symptoms.

CONCLUSIONS

Depressive symptoms predicted lower episodic memory and executive function.

CLINICAL RELEVANCE

Nurses need to pay attention to depressive symptoms in older adults with SCD because managing depressive symptoms may help protect against cognitive decline more typical of early Alzheimer's dementia.

Cortical network modularity changes along the course of frontotemporal and Alzheimer's dementing diseases

Cortical network modularity underpins cognitive functions, so we hypothesized its progressive derangement along the course of frontotemporal (FTD) and Alzheimer's (AD) dementing diseases. EEG was recorded in 18 FTD, 18 AD, and 20 healthy controls (HC). In the FTD and AD patients, the EEG recordings were performed at the prodromal stage of dementia, at the onset of dementia, and three years after the onset of dementia. HC underwent three EEG recordings at 2-3-year time interval. Information flows underlying EEG activity recorded at electrode pairs were estimated by means of Mutual Information (MI) analysis. The functional organization of the cortical network was modelled by means of the Graph theory analysis on MI adjacency matrices. Graph theory analysis showed that the main hub of HC (Parietal area) was lost in FTD patients at onset of dementia, substituted by provincial hubs in frontal leads. No changes in global network organization were found in AD. Despite a progressive cognitive impairment during the FTD and AD progression, only the FTD patients showed a derangement in the cortical network modularity, possibly due to dysfunctions in frontal functional connectivity.

Disease Burdens of Alzheimer's Disease, Vascular Dementia, and Mild Cognitive Impairment

OBJECTIVES

Understanding disability-adjusted life-years (DALYs) based on dementia subtypes and mild cognitive impairment (MCI) is essential for optimal resource allocation. This study aimed to investigate disease burdens of various dementias and MCI in a representative South Korean population.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

6481 Korean older adults.

METHODS

We estimated the disease-specific DALYs.

RESULTS

DALYs due to MCI and all-cause dementia are estimated to increase from 1295 per 100,000 in 2016 to 9501 per 100,000 in 2065. In 2016, DALYs attributed to Alzheimer's dementia, vascular dementia, and MCI accounted for 33% (423 per 100,000), 20% (316 per 100,000), and 24% (123 per 100,000), respectively, of the total DALYs due to MCI and all-cause dementia. In 2065, DALYs due to Alzheimer's dementia, vascular dementia, and MCI will account for 38% (3654 per 100,000), 17% (1654 per 100,000), and 27% (2585 per 100,000) of total DALYs due to MCI and all-cause dementia, respectively. The years of life lived with disability (YLDs) due to MCI and all-cause dementia are estimated to rise from 479 per 100,000 in 2016 to 2807 per 100,000 in 2065. In 2016, YLDs due to Alzheimer's dementia, vascular dementia, and MCI composed 37% (177 per 100,000), 18% (85 per 100,000), and 15% (70 per 100,000), respectively, of the total YLDs due to MCI and all-cause dementia. In 2065, YLDs due to Alzheimer's dementia, vascular dementia, and MCI will account for 48% (1358 per 100,000), 15% (410 per 100,000), and 10% (290 per 100,000), respectively, of total YLDs due to MCI and all-cause dementia.

CONCLUSIONS AND IMPLICATIONS

Considering the rapidly growing disease burden, resources should be allocated to continuously monitor and manage the MCI and dementia burden. Particular attention to Alzheimer's dementia is required considering its significant contribution to current and future disease burden, especially to YLD.

On the Possible Relevance of Bottom-up Pathways in the Pathogenesis of Alzheimer's Disease

Dementia is an increasing health problem in older aged populations worldwide. Age-related changes in the brain can be observed decades before the first symptoms of cognitive decline appear. Cognitive impairment has chronic inflammatory components, which can be enhanced by systemic immune activation. There exist mutual interferences between inflammation and cognitive deficits. Signs of an activated immune system i.e. increases in the serum concentrations of soluble biomarkers such as neopterin or accelerated tryptophan breakdown along the kynurenine axis develop in a significant proportion of patients with dementia and correlate with the course of the disease, and they also have a predictive value. Changes in biomarker concentrations are reported to be associated with systemic infections by pathogens such as cytomegalovirus (CMV) and bacterial content in saliva. More recently, the possible influence of microbiome composition on Alzheimer's disease (AD) pathogenesis has been observed. These observations suggest that brain pathology is not the sole factor determining the pathogenesis of AD. Interestingly, patients with AD display drastic changes in markers of immune activation in the circulation and in the cerebrospinal fluid. Other data have suggested the involvement of factors extrinsic to the brain in the pathogenesis of AD. However, currently, neither the roles of these factors nor their importance has been clearly defined.

2021 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including incidence and prevalence, mortality and morbidity, use and costs of care, and the overall impact on caregivers and society. The Special Report discusses the challenges of providing equitable health care for people with dementia in the United States. An estimated 6.2 million Americans age 65 and older are living with Alzheimer's dementia today. This number could grow to 13.8 million by 2060 barring the development of medical breakthroughs to prevent, slow or cure AD. Official death certificates recorded 121,499 deaths from AD in 2019, the latest year for which data are available, making Alzheimer's the sixth-leading cause of death in the United States and the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2019, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 145%. This trajectory of deaths from AD was likely exacerbated in 2020 by the COVID-19 pandemic. More than 11 million family members and other unpaid caregivers provided an estimated 15.3 billion hours of care to people with Alzheimer's or other dementias in 2020. These figures reflect a decline in the number of caregivers compared with a decade earlier, as well as an increase in the amount of care provided by each remaining caregiver. Unpaid dementia caregiving was valued at $256.7 billion in 2020. Its costs, however, extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes - costs that have been aggravated by COVID-19. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are more than three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 23 times as great. Total payments in 2021 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $355 billion. Despite years of efforts to make health care more equitable in the United States, racial and ethnic disparities remain - both in terms of health disparities, which involve differences in the burden of illness, and health care disparities, which involve differences in the ability to use health care services. Blacks, Hispanics, Asian Americans and Native Americans continue to have a higher burden of illness and lower access to health care compared with Whites. Such disparities, which have become more apparent during COVID-19, extend to dementia care. Surveys commissioned by the Alzheimer's Association recently shed new light on the role of discrimination in dementia care, the varying levels of trust between racial and ethnic groups in medical research, and the differences between groups in their levels of concern about and awareness of Alzheimer's disease. These findings emphasize the need to increase racial and ethnic diversity in both the dementia care workforce and in Alzheimer's clinical trials.

The effect of wavelength on the variability of the flash visual evoked potential P2: A potential biomarker for mild cognitive impairment and Alzheimer's dementia

As the number of individuals diagnosed with amnestic mild cognitive impairment (aMCI) and Alzheimer's dementia (AD) increases, a need exists for early detection and treatment of the disorders. A recent review of the literature conducted by Arruda et al. (2020) revealed that the latency of the flash visual-evoked potential-P2 (FVEP-P2) may possess pathognomic information that may assist in the early detection and treatment of each disease. Unfortunately, while group differences in latency are robust, the ability to discriminate between individuals remains difficult due to the natural variability associated with the FVEP-P2 latency. In the current investigation, we examine the role of wavelength of light in the production of the FVEP-P2, with the goal of reducing the variability associated with the FVEP-P2 latency and improving the diagnostic accuracy of the FVEP-P2 evaluation.

METHOD

Twenty-four healthy individuals (11 males and 13 females), ages 18 to 36 years (M = 25.00, SD = 5.60), participated in this investigation. Each participant experienced five blocks of 100 strobe flashes (or trials) under two different light conditions (blue filtered light and polychromatic white light) with their eyes closed. The FVEP-P2 associated with each trial was identified and the latency and amplitude of each component was calculated.

RESULT

The results of several repeated measures analysis of variance revealed no statistically significant differences in intra- and inter-individual variability associated with the P2 latency or amplitude. However, there was a significant difference in the amplitude of the P2 produced by the two lights, with blue filtered light producing significantly lower amplitudes than the polychromatic white light.

CONCLUSION

The results of the present investigation suggest that while imperfect, the current practice of employing polychromatic white light in the production of the FVEP-P2 remains the gold standard and that additional methods of reducing the natural variability of the P2 need to be developed if the FVEP-P2 latency is to be used as a biomarker.

Late-onset epilepsy predicts stroke: Systematic review and meta-analysis

OBJECTIVE

Late-onset epilepsy (LOE) is closely associated with cerebrovascular disease, acting as both a marker of cerebrovascular disease (CVD) and occurring as a direct consequence. Despite this, our understanding of LOE as a cerebrovascular phenomenon is in its infancy. LOE also appears to be a harbinger of dementia.

METHODS

A systematic review was performed to identify publications relating to LOE and identified observational studies, clinical studies, and radiological studies.

RESULTS

A meta-analysis of observational studies demonstrated that patients presenting with LOE experience an increased risk of subsequent stroke (weighted OR 3.88 (95% CI 2.76-5.46)). The additional studies demonstrated clinical and radiological evidence to support the premise that LOE is likely to reflect underlying cerebrovascular disease.

SIGNIFICANCE

Cerebrovascular disease risk factors convey increased risk of LOE and LOE can precede stroke and dementia, acting as an early marker for cerebrovascular risk. This may represent a potential point for intervention. There are a number of suggested mechanisms relating LOE to stroke; however, there is limited understanding of the natural history of LOE. Current data support the need for prospective research in order to understand the natural history of LOE and modify disease, in order to reduce the apparent sequelae of stroke and dementia.

Pharmacological and non-pharmacological interventions to enhance sleep in mild cognitive impairment and mild Alzheimer's disease: A systematic review

Suboptimal sleep causes cognitive decline and probably accelerates Alzheimer's Disease (AD) progression. Several sleep interventions have been tested in established AD dementia cases. However early intervention is needed in the course of AD at Mild Cognitive Impairment (MCI) or mild dementia stages to help prevent decline and maintain good quality of life. This systematic review aims to summarize evidence on sleep interventions in MCI and mild AD dementia. Seven databases were systematically searched for interventional studies where ≥ 75% of participants met diagnostic criteria for MCI/mild AD dementia, with a control group and validated sleep outcome measures. Studies with a majority of participants diagnosed with Moderate to Severe AD were excluded. After removal of duplicates, 22,133 references were returned in two separate searches (August 2019 and September 2020). 325 full papers were reviewed with 18 retained. Included papers reported 16 separate studies, total sample (n = 1,056), mean age 73.5 years. 13 interventions were represented: Cognitive Behavioural Therapy – Insomnia (CBT‐I), A Multi‐Component Group Based Therapy, A Structured Limbs Exercise Programme, Aromatherapy, Phase Locked Loop Acoustic Stimulation, Transcranial Stimulation, Suvorexant, Melatonin, Donepezil, Galantamine, Rivastigmine, Tetrahydroaminoacridine and Continuous Positive Airway Pressure (CPAP). Psychotherapeutic approaches utilising adapted CBT‐I and a Structured Limbs Exercise Programme each achieved statistically significant improvements in the Pittsburgh Sleep Quality Index with one study reporting co‐existent improved actigraphy variables. Suvorexant significantly increased Total Sleep Time and Sleep Efficiency whilst reducing Wake After Sleep Onset time. Transcranial Stimulation enhanced cortical slow oscillations and spindle power during daytime naps. Melatonin significantly reduced sleep latency in two small studies and sleep to wakefulness transitions in a small sample. CPAP demonstrated efficacy in participants with Obstructive Sleep Apnoea. Evidence to support other interventions was limited. Whilst new evidence is emerging, there remains a paucity of evidence for sleep interventions in MCI and mild AD highlighting a pressing need for high quality experimental studies exploring alternative sleep interventions.

Vitamin D intake is associated with dementia risk in the Washington Heights-Inwood Columbia Aging Project (WHICAP)

INTRODUCTION

Low vitamin D intake and low vitamin D circulating levels have been associated with increased risk for dementia. We aimed to examine the association between vitamin D intake and dementia in a multiethnic cohort.

METHODS

A longitudinal study of 1759 non-demented older (≥65 years) participants of the Washington Heights-Inwood Columbia Aging Project with follow-up visits and completed a food frequency questionnaire. Dementia was diagnosed by consensus using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. Cox hazard regression was performed.

RESULTS

During a mean follow-up of 5.8 years, 329 participants developed dementia. Participants with the highest tertile of vitamin D intake from food sources had decreased risk (hazard ratio [HR] 0.72, 95% confidence interval [CI] 0.54-0.97, P = .030) for dementia compared with those with the lowest tertile, adjusting for age, sex, race/ethnicity, education, apolipoprotein E (APOE)-ε4, physical activity, Mediterranean diet (MeDI) score, income, depression, hypertension, diabetes, cardiovascular disease, and smoking.

DISCUSSION

Higher vitamin D intake is associated with decreased risk of dementia in a multiethnic cohort.

Factors predicting episodic memory changes in older adults with subjective cognitive decline: A longitudinal observational study

Episodic memory is affected early in the neuropathological process of Alzheimer's dementia. This study was performed to identify longitudinal associations between baseline vascular/neuropsychiatric risk factors and episodic memory changes over 4.1 ± 2.4 years in 1,401 older adults with subjective cognitive decline (age 74.0 ± 8.2 years). Data were from the National Alzheimer's Coordinating Center-Uniform Data Set and linear mixed effects regression models were used. Reference was those without risk factors. Participants with hypercholesterolemia and with former cigarette smoking had higher episodic memory scores, but current smokers had fewer points than reference at their first and follow-up visits. Despite no difference at baseline, episodic memory scores decreased in those with depressive symptoms relative to reference over time. In older adults with subjective cognitive decline, interventions managing current smoking and depressive symptoms could preserve episodic memory, which may result in delaying the onset of Alzheimer's dementia. Further research is required for the role of cholesterol and smoking.

Reduced uptake of [11C]-ABP688, a PET tracer for metabolic glutamate receptor 5 in hippocampus and amygdala in Alzheimer's dementia

INTRODUCTION

Metabotropic glutamate receptors play a critical role in the pathogenesis of Alzheimer's disease due to their involvement in processes of memory formation, neuroplasticity, and synaptotoxity. The objective of the current study was to study mGluR5 availability measured by [¹¹ C]-ABP688 (ABP) in patients with clinically diagnosed Alzheimer's dementia (AD).

METHODS

A bolus-infusion protocol of [¹¹ C]-ABP688 was applied in 9 subjects with AD and 10 cognitively healthy controls (Controls) to derive distribution volume estimates of mGluR5. Furthermore, we also estimated cerebral perfusion by averaging early frame signal of initial ABP bolus injection.

RESULTS

Subjects with Alzheimer's dementia (mean age: 77.3/SD 5.7) were older than controls (mean age: 68.5/SD: 9.6) and scored lower on the MMSE (22.1/SD2.7 vs. 29.0/SD0.8). There were no overall differences in ABP signal. However, distribution volume ratio (DVR) for ABP was reduced in the bilateral hippocampus (AD: 1.34/SD: 0.40 vs. Control: 1.84/SD:0.31, p = .007) and the bilateral amygdala (AD:1.86/SD:0.26 vs. Control:2.33/SD:0.37 p = .006) in AD patients compared to controls. Estimate of cerebral blood flow was reduced in the bilateral hippocampus in AD (AD:0.75/SD:0.10 vs. Control:0.86/SD:0.09 p = .02).

CONCLUSION

Our findings demonstrate reduced mGluR5 binding in the hippocampus and amygdala in Alzheimer's dementia. Whether this is due to synaptic loss and/or consecutive reduction of potential binding sites or reflects disease inherent mechanisms remains to be elucidated in future studies.

Serum Concentrations of Cholinesterase Inhibitors in Patients With Alzheimer's Dementia Are Frequently Below the Recommended Levels

Background

Acetylcholinesterase inhibitors (AChE-I) are recommended for the treatment of cognitive symptoms but also of behavioral and psychological symptoms in dementia. They are widely used not only in Alzheimer's disease, but also in other forms of dementia. Efficacy of treatment might depend on serum concentration of the respective AChE-I.

Objective

In patients with mild to moderate Alzheimer's dementia, we measured serum concentrations of hepatically metabolized donepezil and renally excreted rivastigmine and investigated possible modifiers. Additionally, we looked at correlations between serum concentrations and efficacy for both drugs.

Methods

Serum concentrations of donepezil and rivastigmine were measured by liquid chromatography – tandem mass spectrometry (LC-MS/MS). Real-time quantitative polymerase chain reaction (PCR). Allele specific PCR were performed to determine CYP2D6 genotype and gene dose. Clinical efficacy was assessed by changes of the subtest wordlist delayed recall of the Consortium to Establish a Registry for Alzheimer's Disease-Neuropsychological Assessment Battery (CERAD-NAB).

Results

Sixty-seven patients treated with a stable dosage of donepezil 10 mg (n=41) or rivastigmine 9.5 mg (n=26) were included. Mean serum concentration of donepezil and rivastigmine were 41.2 and 6.5 ng/ml, respectively. Serum concentrations were below the recommended range in 73% of the subjects in the donepezil group and in 65% of the participants in the rivastigmine group. When applying a dose-related reference, ranges 63% of patients in the donepezil group and 32% in the rivastigmine group had concentrations below the expected range. Gene dose, sex, and duration of treatment significantly predicted donepezil serum concentration (p=0.046, p=0.001, p=0.030 respectively). Only for rivastigmine did the serum concentration significantly contribute to the regression model predicting changes on the subtest word list delayed recall (β=0.472; p=0.019).

Conclusions

Serum concentrations of about two thirds of the patients were below the recommended range. When not looking at absolute values but at the dose-related reference ranges, these numbers improved but still 32%, respectively 63% of patients had low serum concentrations. High serum concentrations of rivastigmine predicted clinical response to cognition. Therapeutic drug monitoring might help to identify the cause of poor clinical response to cognition and behavioral and psychological symptoms in patients with AChE-I treatment.

Treatment of Neurodegeneration: Integrating Photobiomodulation and Neurofeedback in Alzheimer's Dementia and Parkinson's: A Review

Objective: A review of photobiomodulation (PBM) in Alzheimer's dementia is submitted. The addition of PBM in neurodegenerative diseases is a dual modality that is at present gaining traction as it is safe, antiviral, and anti-inflammatory for treating neurodegeneration with photons that stimulate mitochondria increasing adenosine triphosphate and proteasomes increasing misfolded protein removal. Neurofeedback provides neural plasticity with an increase in brain-derived nerve factor mRNA and an increase in dendrite production and density in the hippocampus coupled with overall growth in dendrites, density, and neuronal survival. Background: Alzheimer's disease pathophysiology is the accumulation of hyperphosphorylated tau protein neurofibrillary tangles and subsequently amyloid-beta (Aβ) plaques. PBM and neurobiofeedback (NBF)address the multiple gene expression and upregulation of multiple pathogenic pathway inflammation, reactive oxidative stress, mitochondrial disorders, insulin resistance, methylation defects, regulation of neuroprotective factors, and regional hypoperfusion of the brain. There is no human evidence to suggest a clinical therapeutic benefit from using consistent light sources while significantly increasing safety concerns. Methods: A PBM test with early- to mid-Alzheimer's was reported in 2017, consisting of a double-blind, placebo-controlled trial in a small pilot group of early- to mid-dementia subjects under Institutional Review Board (IRB)-approved Food and Drug Administration (FDA) Clinical Trial. Results: PBM-treated subjects showed that active treatment subjects tended to show greater improvement in the functioning of the executive: clock drawing, immediate recall, practical memory, and visual attention and task switching (Trails A&B). A larger study using the CerebroLite helmet in Temple Texas again of subjects in a double-blind, placebo-controlled IRB-approved FDA Clinical Trial demonstrated gain in memory and cognition by increased clock drawing. Conclusions: Next-generation trials with the Cognitolite for Parkinson's disease subjects will incorporate the insights regarding significant bilateral occipital hypocoherence deficits gained from the quantitative EEG analyses. Future applications will integrate noninvasive stimulation delivery, including full-body and transcranial and infrared light with pulsed electromagnetic frequencies.

2020 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including incidence and prevalence, mortality and morbidity, use and costs of care, and the overall impact on caregivers and society. The Special Report discusses the future challenges of meeting care demands for the growing number of people living with Alzheimer's dementia in the United States with a particular emphasis on primary care. By mid-century, the number of Americans age 65 and older with Alzheimer's dementia may grow to 13.8 million. This represents a steep increase from the estimated 5.8 million Americans age 65 and older who have Alzheimer's dementia today. Official death certificates recorded 122,019 deaths from AD in 2018, the latest year for which data are available, making Alzheimer's the sixth leading cause of death in the United States and the fifth leading cause of death among Americans age 65 and older. Between 2000 and 2018, deaths resulting from stroke, HIV and heart disease decreased, whereas reported deaths from Alzheimer's increased 146.2%. In 2019, more than 16 million family members and other unpaid caregivers provided an estimated 18.6 billion hours of care to people with Alzheimer's or other dementias. This care is valued at nearly $244 billion, but its costs extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are more than three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 23 times as great. Total payments in 2020 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $305 billion. As the population of Americans living with Alzheimer's dementia increases, the burden of caring for that population also increases. These challenges are exacerbated by a shortage of dementia care specialists, which places an increasing burden on primary care physicians (PCPs) to provide care for people living with dementia. Many PCPs feel underprepared and inadequately trained to handle dementia care responsibilities effectively. This report includes recommendations for maximizing quality care in the face of the shortage of specialists and training challenges in primary care.

Brain and blood metabolome for Alzheimer's dementia: findings from a targeted metabolomics analysis

The development of Alzheimer's dementia (AD) accompanies both central and peripheral metabolic disturbance, but the metabolic basis underlying AD and metabolic markers predictive of AD risk remain to be determined. It is also unclear whether the metabolic changes in the peripheral blood and brain are overlapping in relation to AD. The present study addresses these questions by targeted metabolomics in both antemortem blood and postmortem brain samples in 2 community-based longitudinal cohorts of aging and dementia. We found that higher serum levels of 3 acylcarnitines, including decanoylcarnitine (C10), pimelylcarnitine (C7-DC), and tetradecadienylcarnitine (C14:2), significantly predict a lower risk of incident AD (composite hazard ratio = 0.368, 95% CI [0.207, 0.653]) after an average of 4.5-year follow-up, independent of age, sex, and education. In addition, baseline serum levels of ten glycerophospholipids, one amino acid, and 5 acylcarnitines predict the longitudinal change in cognitive functions. Moreover, 28 brain metabolites were associated with AD phenotypes. Of the putative metabolites identified in the serum and brain, 4 metabolites (3 glycerophospholipids [PC aa C30:0, PC ae C34:0, PC ae C36:1] and 1 acylcarnitine [C14:2]) were present in both the postmortem brain and antemortem blood, but only one metabolite (C14:2) was associated with AD in the same direction (i.e., protective). Partial correlation and network analyses suggest a potential tissue-specific regulation of metabolism, although other alternatives exist. Together, we identified significant associations of both central and peripheral metabolites with AD phenotypes, but there seems to be little overlap between the 2 tissues.

Cambridge Cognitive Examination and Hachinski Ischemic Score as predictors of MRI confirmed pathology in dementia: A cross-sectional study

AIMS AND BACKGROUND

Dementia is diagnosed through a combination of clinical assessment, cognitive assessment tools and neuroimaging. The aim of this retrospective, naturalistic study was to explore the association between the clinical assessment tools used in a memory clinic and the findings of Magnetic Resonance Imaging (MRI) scans in patients with dementia.

METHODS

Data were collected through routine clinical practice for all patients assessed at a memory assessment clinic in East Sussex, UK. Included patients had an MRI scan and received a formal diagnosis of dementia. Multinomial logistic regression was used to investigate the associations between atrophy on MRI with age, gender, Cambridge Cognitive Examination (CAMCOG) and Hachinski Ischemic Score (HIS). Ordinal logistic regression was used to study the associations between vascular findings on MRI with age, gender, CAMCOG and HIS. Because of the distribution of HIS scores a cut-off of 1 or greater was used in the regression analysis.

RESULTS

Male gender was associated with an increased likelihood of moderate atrophy (relative risk ratio (RRR) = 1.99, 95% confidence interval (CI) = 1.04-3.82), severe atrophy (RRR = 3.04, 95% CI = 1.38-6.68) and regional atrophy (RRR = 2.25, 95% CI = 1.26-4.00) on MRI. An increase of one point on the CAMCOG was associated with a decreased risk of regional atrophy (RRR = 0.98, 95% CI = 0.96-1.00) on MRI. There were no significant associations between age, or HIS, and atrophy on MRI. An increase in age of one year was associated with an increase in severity of vascular pathology reported on MRI (OR = 1.08, 95% CI = 1.05-1.12). Male gender was associated with reduced severity of vascular pathology reported on MRI (OR = 0.53, 95% CI = 0.36-0.78). There were no associations between CAMCOG, or HIS, and vascular pathology on MRI.

DISCUSSION

Our data show that CAMCOG was associated with MRI findings of regional atrophy and vascular pathology was greater in older patients. We highlight the importance of using a multi-modal approach to dementia diagnosis.

The Contribution of Cerebral Vascular Neuropathology to Mild Stage of Alzheimer's Dementia Using the NACC Database

BACKGROUND

The interaction between cerebral vessel disease (CVD) pathology and Alzheimer's disease (AD) pathology in the development of dementia is controversial. We examined the association of cerebral vascular neuropathology and cerebrovascular risk factors with the mild stage of Alzheimer's dementia and cognitive function.

METHODS

This cross-sectional study included men and women aged 60 years or over who had yearly clinical assessments and had agreed to brain autopsy at the time of death, and who contributed to data stored at the National Alzheimer's Coordinating Center (NACC) in the USA. Cognitively normal and impaired subjects with presumptive aetiology of AD, including mild cognitive impairment (ADMCI) and dementia (Alzheimer's dementia), and with complete neuropathological data, were included in our analyses. We used neuropsychological data proximate to death to create summary measures of global cognition and cognitive domains. Systematic neuropathological assessments documenting the severity of cerebral vascular pathology were included. Logistic and linear regression analyses corrected for age at death, sex and Lewy body pathology were used to examine associations of vessel disease with the severity of Alzheimer's disease dementia, and cognitive function, respectively.

RESULTS

No significant relationship was observed between late-life risk factors and Alzheimer's dementia. The severity of arteriosclerosis and presence of global infarcts/lacunes were related to mild Alzheimer's dementia (B=0.423, p<0.001; B=0.366, p=0.026), and the effects were significant after adjusting for neuritic plaques and neurofibrillary tangles (B=0.385, p<0.001; B=0.63, p=0.001). When vascular brain injuries were subdivided into old and acute/subacute types, we found that old microinfarcts and old microbleeds were associated with mild Alzheimer's dementia (B=0.754, p=0.007; B=2.331, p=0.032). The old microinfarcts remained significantly associated with mild Alzheimer's dementia after correcting AD pathologies (B=1.31, p<0.001). In addition, the number of microinfarcts in the cerebral cortex had a significant relation with mild Alzheimer's dementia, whether or not the data were corrected for AD pathologies (B=0.616, p=0.016; B=0.884, p=0.005). Atherosclerosis, arteriosclerosis and white matter rarefaction were found to be significantly associated with faster progression of Alzheimer's dementia (B=0.068, p=0.001; B=0.046, p=0.016, B=0.081, p=0.037), but white matter rarefaction no longer had a significant effect after adjusting for AD pathologies. We also found that the severity of atherosclerosis was related to impairment in processing speed (β=-0.112, p=0.006) and executive function (β=-0.092, p=0.023). Arteriosclerosis was significantly associated with language (β=-0.103, p=0.011) and global cognition (β=-0.098, p=0.016) deficits.

CONCLUSION

Our study found the significant relation of global, old, acute/subacute and regional cerebral vascular pathologies, but not white matter rarefaction, to the onset and severity of Alzheimer's dementia. We also showed that late-life risk factors were found to have no relation with Alzheimer's dementia, and the increased risk of dementia with APOE ε4 is not mediated by CVD. The best interpretation of these findings is that CVD has a potential additive effect with AD pathologies in the development and progression of what is clinically diagnosed as Alzheimer's dementia.

Body Weight Variability Increases Dementia Risk Among Older Adults: A Nationwide Population-Based Cohort Study

Background: Recent growing evidences suggest that body weight (Bwt) variability, a repeated loss and regain of weight within a specific period, causes metabolic disturbances and can be a marker for poor homeostasis. Although there have been many studies about the association between Bwt variability and various health status, its association with the incidence of dementia among elderly people has not been examined. Methods: We performed a retrospective elderly cohort study from 19,987 participants with mean age 73 years old in the Korean National Health Insurance Service. We examined the risk of incident dementia, including Alzheimer's dementia and vascular dementia, according to the quartile of Bwt variability, represented as coefficient of variation (Bwt-CV), SD (Bwt-SD), and variability independent of the mean (Bwt-VIM). Results: In fully adjusted model, the group with the highest Bwt variability (Bwt-VIM Q4) showed an increased risk of all-cause dementia (hazard ratio [HR] 1.39, 95% confidence interval [CI] 1.206-1.603) and Alzheimer's dementia (HR 1.46, CI 1.240-1.724) compared to the lowest quartile (Bwt-VIM Q1). We also found that subjects with the highest Bwt variability (Q4) and underweight BMI had a significantly increased risk of developing dementia (HR 1.994, 95% CI 1.302-3.054), while subjects with low Bwt variability (Q1 and Q2) and obese BMI had decreased risk of dementia (HR 0.664, 95% CI 0.505-0.872 and HR 0.648, 95% CI 0.493-0.852, respectively) compared to reference group (lowest Bwt variability (Q1) with normal baseline BMI). The effect of Bwt variability on the incidence of dementia was more prominent in subjects <75 years old and abnormal BMI groups (P for interaction < 0.05). Conclusion: The present study revealed that high Bwt variability was associated with an increased risk of dementia in the elderly.

Patterns of olfactory functional networks in Parkinson's disease dementia and Alzheimer's dementia

Hyposmia is common in Alzheimer's dementia (AD) and Parkinson's disease dementia (PDD). We evaluated the pattern of olfactory functional connectivity (FC) in AD and PDD to uncover neural correlates that are related to olfactory dysfunction. This study enrolled 57 patients with AD and PDD and 25 control subjects. Using a seed-based approach, we compared the resting-state network from the seed-region-of-interest in the olfactory bulb, olfactory tract, piriform cortex, and orbitofrontal cortex (OFC) between groups. The PDD group showed lower FC with striatal-thalamic-frontal regions from the olfactory bulb than the AD group. The PDD group showed lower FC from left OFC with striatal-frontal regions and lower FC from right OFC with left fronto-temporal areas than the AD group. In a correlation analysis, the FC from left OFC with right insula that differed between the PDD and control groups was positively correlated with olfactory function. The present study demonstrated that this distinct olfactory functional network pattern may represent different neural mechanisms for olfactory dysfunction in AD and PDD.