Diagnosis and Management of Dementia: Review

Fear about Alzheimer's disease among Israeli and German laypersons, persons with Mild Neurocognitive Disorder and their relatives: a qualitative study

OBJECTIVES

Alzheimer's disease (AD), the most common type of dementia, is one of the most feared diseases, obstructing help-seeking, and leading to discrimination. While research interest in fear of developing AD is increasing, little is known about its characterization, triggers, and consequences, especially among different cultures. In this study, we aimed at exploring and characterizing AD fear as experienced by laypersons (LP), persons with Mild Neurocognitive Disorder (MND), and their relatives, in Israel and Germany.

DESIGN

A qualitative study using focus groups (FGs) and semi-structured interviews was used. Thematic content analysis was conducted to extract key themes.

SETTING

Israeli and German not yet diagnosed people.

PARTICIPANTS

The study included a total of 130 participants (63 Israeli and 67 German participants) representing 3 groups: LP (n = 82), persons with MND (n = 28), and relatives of persons with MND (n = 20).

RESULTS

Two overarching themes were identified across groups and countries: fear of developing AD and fear of stigmatization. Other types of fear, such as fear of a person with AD, fear about the impact of a diagnosis of AD on family members, fear of becoming a caregiver, and fear of losing one's self-determination because of developing AD, were specific to a group type or country. Different types of fear were awakened by different triggers, and were dealt with different coping strategies.

The histone code in dementia: Transcriptional and chromatin plasticity fades away

With the aging of the population, Alzheimer's disease and other forms of dementia represent major challenges for health care systems globally. To date, the molecular mechanisms underlying the pathophysiology of dementia remain elusive, with a consequent negative impact in developing efficient disease modifiers. New exciting findings suggest that modulation of the histone code may influence transcriptional networks at the root of neuronal plasticity and cognitive performance. Although most of the current conclusions require further mechanistic evidence, it appears that chromatin perturbations actually correlate with Alzheimer's disease onset and progression. Thus, a better understanding of the epigenetic contribution to normal brain function and dementia pathogenesis may help to identify new epigenetic targets for the inhibition of disease trajectories associated with cognitive decline.

Identification of novel drug targets for Alzheimer's disease by integrating genetics and proteomes from brain and blood

Genome-wide association studies (GWASs) have discovered numerous risk genes for Alzheimer's disease (AD), but how these genes confer AD risk is challenging to decipher. To efficiently transform genetic associations into drug targets for AD, we employed an integrative analytical pipeline using proteomes in the brain and blood by systematically applying proteome-wide association study (PWAS), Mendelian randomization (MR) and Bayesian colocalization. Collectively, we identified the brain protein abundance of 7 genes (ACE, ICA1L, TOM1L2, SNX32, EPHX2, CTSH, and RTFDC1) are causal in AD (P < 0.05/proteins identified for PWAS and MR; PPH4 >80% for Bayesian colocalization). The proteins encoded by these genes were mainly expressed on the surface of glutamatergic neurons and astrocytes. Of them, ACE with its protein abundance was also identified in significant association with AD on the blood-based studies and showed significance at the transcriptomic level. SNX32 was also found to be associated with AD at the blood transcriptomic level. Collectively, our current study results on genetic, proteomic, and transcriptomic approaches has identified compelling genes, which may provide important leads to design future functional studies and potential drug targets for AD.

Sex, Sleep Duration, and the Association of Cognition: Findings from the China Health and Retirement Longitudinal Study

BACKGROUND

We aimed to examine the association between sleep duration and cognitive impairment among elderly Chinese people.

METHODS

generalized linear modeling was used to analyze the baseline data for adults aged 65 years and over (n = 4785) selected from the 2011 China Health and Retirement Longitudinal Study (CHARLS). The two aspects of cognitive impairment assessed in the study were mental status and memory. Sex-stratified logistic regression models were conducted to identify the effect of sleep duration in the different gender groups.

RESULTS

of all the participants, 49.8% were females and 32.5% aged 75 years and over. Of the participants, 59.7% had short sleep duration (<7 h/day), and 9.0% of them had long sleep duration (>8 h/day). Compared to normal sleep duration, long sleep duration was associated with lower mental status scores (β = -0.43, p = 0.001) and lower memory scores (β = -0.26, p = 0.006). Long sleep duration was associated with lower mental status in both men (β = -0.37, p = 0.033) and women (β = -0.46, p = 0.025), however, only in men was long sleep duration found to be associated with low memory scores (β = -0.26, p = 0.047).

CONCLUSIONS

Our study showed that long sleep duration was significantly associated with poorer mental status and memory scores in elderly Chinese people. Paying greater attention to the effects of sleep patterns on the risk of cognitive decline may yield practical implications for dementia prevention and health promotion, especially among older women with lower educational attainment, living in rural areas, and those who have long sleep duration.

Eating Difficulties among Older Adults with Dementia in Long-Term Care Facilities: A Scoping Review

This paper reports a scoping review of the literature on eating difficulties among older adults with dementia in long-term care facilities to identify key concepts, methods of measuring outcomes, interventions, and related factors. A scoping review was performed using the bibliographic databases PubMed, CINAHL, PsycINFO, and Cochrane Library. A combination of keywords and subject headings related to eating or feeding difficulties was used. Inclusion criteria were limited to materials published in English. A total of 1070 references were retrieved, of which 39 articles were selected after applying the inclusion and exclusion criteria. Articles that met the criteria were published between 1987 and 2020. "Eating disabilities" have been defined as problems related to choosing food and/or the ability to get food to one's mouth, chew, and swallow. Interventions for eating difficulties described in the literature include spaced retrieval training, Montessori training, and feeding skill training. Intrapersonal, interpersonal, and environmental factors related to eating difficulties were identified. This scoping review will provide direct care workers, nursing educators, and administrators with an overview of eating performance and a broad understanding of eating difficulties for older adults with dementia in long-term care facilities.

Long-term diet quality and its change in relation to late-life subjective cognitive decline

BACKGROUND

Evidence regarding the role of diet quality, especially its change, in subjective cognitive decline (SCD) is scarce.

OBJECTIVES

We aimed to examine associations of long-term diet quality scores, including the Alternate Mediterranean Diet (AMED), Dietary Approaches to Stop Hypertension (DASH), and Alternate Healthy Eating Index 2010 (AHEI-2010), with SCD in the Nurses' Health Study.

METHODS

We followed 49,493 female registered nurses (mean age in 1984: 48 y) from 1984 to 2014. Diet scores were derived from 7 repeated FFQs in 1984, 1986, and every 4 y afterward until 2006. Self-reported SCD was assessed in 2012 and 2014 by a 7-item questionnaire on memory and cognition changes. Categorical SCD score was classified as "none" (0 points, 40.8%), "moderate" (0.5-2.5 points, 46.9%), and "severe" (3-7 points, 12.3%).

RESULTS

Multinomial and linear regression models were adjusted for total calorie intake, demographic characteristics, lifestyle, and clinical factors. Comparing the top with the bottom quintiles of AMED, DASH, and AHEI-2010, multivariable-adjusted ORs (95% CIs) for severe SCD compared with none were 0.57 (0.51, 0.64), 0.61 (0.55, 0.68), and 0.81 (0.73, 0.90), respectively. Similar associations remained for the 3 diet indexes evaluated 28 y before SCD assessment. Compared with participants with the lowest diet quality tertiles in both remote and recent years, the lowest odds of severe SCD were observed among those who maintained the highest diet quality tertiles over time, with 40%, 32%, and 20% lower odds of severe SCD for AMED, DASH, and AHEI-2010, respectively. Moreover, the odds of severe SCD were lower among those with improved diets over time; for each SD higher in diet quality change, the reductions in risk were 11% for AMED, 5% for DASH, and 3% for AHEI-2010, respectively.

CONCLUSIONS

Our findings support beneficial roles of long-term adherence to, and improvement in, healthy dietary patterns for the maintenance of subjective cognition in women.

Nuts: Natural Pleiotropic Nutraceuticals

Common nuts (tree nuts and peanuts) are energy-dense foods that nature has gifted with a complex matrix of beneficial nutrients and bioactives, including monounsaturated and polyunsaturated fatty acids, high-quality protein, fiber, non-sodium minerals, tocopherols, phytosterols, and antioxidant phenolics. These nut components synergize to favorably influence metabolic and vascular physiology pathways, ameliorate cardiovascular risk factors and improve cardiovascular prognosis. There is increasing evidence that nuts positively impact myriad other health outcomes as well. Nut consumption is correlated with lower cancer incidence and cancer mortality, and decreased all-cause mortality. Favorable effects on cognitive function and depression have also been reported. Randomized controlled trials consistently show nuts have a cholesterol-lowering effect. Nut consumption also confers modest improvements on glycemic control, blood pressure (BP), endothelial function, and inflammation. Although nuts are energy-dense foods, they do not predispose to obesity, and in fact may even help in weight loss. Tree nuts and peanuts, but not peanut butter, generally produce similar positive effects on outcomes. First level evidence from the PREDIMED trial shows that, in the context of a Mediterranean diet, consumption of 30 g/d of nuts (walnuts, almonds, and hazelnuts) significantly lowered the risk of a composite endpoint of major adverse cardiovascular events (myocardial infarction, stroke, and death from cardiovascular disease) by ≈30% after intervention for 5 y. Impressively, the nut-supplemented diet reduced stroke risk by 45%. As they are rich in salutary bioactive compounds and beneficially impact various health outcomes, nuts can be considered natural pleiotropic nutraceuticals.

Investigation of combined treatment of acupuncture and neurofeedback for improving cognitive function in mild neurocognitive disorder: A randomized, assessor-blind, pilot study

BACKGROUND

Mild neurocognitive disorder (MND) is an intermediate state that can progress to dementia, and the cognitive reserve of MND is an important task in preventing dementia. Acupuncture and neurofeedback (NF) training have been used to improve cognitive function and treat MND or dementia, but their effectiveness remains controversial. In this trial, we will evaluate the efficacy and safety of combined NF-acupuncture treatment in comparison with single acupuncture treatment.

METHODS AND DESIGN

This study is a randomized, assessor-blind, pilot trial. It is designed in accordance with the Standards for Reporting Interventions in Controlled Trials of Acupuncture. A total of 44 MND participants who meet the inclusion and exclusion criteria will be enrolled, and each will be randomly assigned to 1 of 2 groups of 22 subjects. Each subject will visit 24 times over 12 weeks and receive either acupuncture or NF-acupuncture combined treatment. At visit 25 (week 13), a follow-up evaluation will be performed, and then the investigator will analyze the results. The primary outcome is defined by the Korean version of the Montreal Cognitive Assessment score from screening to visit 25. The secondary outcome includes the following: change in Alzheimer Disease Assessment Scale-Cognitive, the Korean version of the Beck Depression Inventory, Body Awareness Questionnaire, delayed matching to sample task scores, and functional near-infrared spectroscopy values, from visit 1 to visit 25; heart rate variability values from visit 1 to visit 5, visit 9, visit 13, visit 21, visit 25; breath per minute values from visit 1 to visit 1 to 25.

DISCUSSION

We will evaluate the effectiveness and safety of combined NF-acupuncture therapy, and expect that it will serve as the basis for the use of NF together with acupuncture in the clinical setting.

TRIAL REGISTRATION NUMBER

KCT0004972 (registered in Clinical Research Information Service of the Republic of Korea, https://cris.nih.go.kr/cris/search/detailSearch.do/16239).

Whole-blood metabolomics of dementia patients reveal classes of disease-linked metabolites

Dementia is caused by factors that damage neurons. We quantified small molecular markers in whole blood of dementia patients, using nontargeted liquid chromatography-mass spectroscopy (LC-MS). Thirty-three metabolites, classified into five groups (A to E), differed significantly in dementia patients, compared with healthy elderly subjects. Seven A metabolites present in plasma, including quinolinic acid, kynurenine, and indoxyl-sulfate, increased. Possibly they act as neurotoxins in the central nervous system (CNS). The remaining 26 compounds (B to E) decreased, possibly causing a loss of support or protection of the brain in dementia. Six B metabolites, normally enriched in red blood cells (RBCs), all contain trimethylated ammonium moieties. These metabolites include ergothioneine and structurally related compounds that have scarcely been investigated as dementia markers, validating the examination of RBC metabolites. Ergothioneine, a potent antioxidant, is significantly decreased in various cognition-related disorders, such as mild cognitive impairment and frailty. C compounds also include some oxidoreductants and are normally abundant in RBCs (NADP+, glutathione, adenosine triphosphate, pantothenate, S-adenosyl-methionine, and gluconate). Their decreased levels in dementia patients may also contribute to depressed brain function. Twelve D metabolites contains plasma compounds, such as amino acids, glycerophosphocholine, dodecanoyl-carnitine, and 2-hydroxybutyrate, which normally protect the brain, but their diminution in dementia may reduce that protection. Seven D compounds have been identified previously as dementia markers. B to E compounds may be critical to maintain the CNS by acting directly or indirectly. How RBC metabolites act in the CNS and why they diminish significantly in dementia remain to be determined.

Deep Learning and Risk Score Classification of Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND

Many neurocognitive and neuropsychological tests are used to classify early mild cognitive impairment (EMCI), late mild cognitive impairment (LMCI), and Alzheimer's disease (AD) from cognitive normal (CN). This can make it challenging for clinicians to make efficient and objective clinical diagnoses. It is possible to reduce the number of variables needed to make a reasonably accurate classification using machine learning.

OBJECTIVE

The goal of this study was to develop a deep learning algorithm to identify a few significant neurocognitive tests that can accurately classify these four groups. We also derived a simplified risk-stratification score model for diagnosis.

METHODS

Over 100 variables that included neuropsychological/neurocognitive tests, demographics, genetic factors, and blood biomarkers were collected from 383 EMCI, 644 LMCI, 394 AD patients, and 516 cognitive normal from the Alzheimer's Disease Neuroimaging Initiative database. A neural network algorithm was trained on data split 90% for training and 10% testing using 10-fold cross-validation. Prediction performance used area under the curve (AUC) of the receiver operating characteristic analysis. We also evaluated five different feature selection methods.

RESULTS

The five feature selection methods consistently yielded the top classifiers to be the Clinical Dementia Rating Scale - Sum of Boxes, Delayed total recall, Modified Preclinical Alzheimer Cognitive Composite with Trails test, Modified Preclinical Alzheimer Cognitive Composite with Digit test, and Mini-Mental State Examination. The best classification model yielded an AUC of 0.984, and the simplified risk-stratification score yielded an AUC of 0.963 on the test dataset.

CONCLUSION

The deep-learning algorithm and simplified risk score accurately classifies EMCI, LMCI, AD and CN patients using a few common neurocognitive tests.

Metabolomic Alterations in the Blood and Brain in Association with Alzheimer's Disease: Evidence from in vivo to Clinical Studies

Alzheimer's disease (AD) has become a major health problem among the elderly population. Some evidence suggests that metabolic disturbance possibly plays a role in the pathophysiology of AD. Currently, the study of metabolomics has been used to explore changes in multiple metabolites in several diseases, including AD. Thus, the metabolomics research in AD might provide some information regarding metabolic dysregulations, and their possible associated pathophysiology. This review summarizes the information discovered regarding the metabolites in the brain and the blood from the metabolomics research of AD from both animal and clinical studies. Additionally, the correlation between the changes in metabolites and outcomes, such as pathological findings in the brain and cognitive impairment are discussed. We also deliberate on the findings of cohort studies, demonstrating the alterations in metabolites before changes of cognitive function. All of these findings can be used to inform the potential identity of specific metabolites as possible biomarkers for AD.

Quality of Life in Advanced Dementia with Late Onset, Young Onset, and Very Young Onset

Background:

Advanced stages of dementia are characterized by severe cognitive and physical impairment. It has not yet been investigated whether persons with young onset dementia (YOD) and late onset dementia (LOD) differ in advanced disease stages.

Objectives:

To compare quality of life (QoL) between persons with advanced YOD and LOD; to explore the determinants of QoL; to investigate whether YOD and LOD differ with regard to symptoms and care.

Methods:

The study was performed in the context of EPYLOGE (IssuEs in Palliative care for persons in advanced and terminal stages of YOD and LOD in Germany). Persons with advanced dementia (PWAD) were assessed and caregivers were interviewed. QoL was measured with the proxy rating Quality of Life in Late Stage Dementia (QUALID) scale.

Results:

93 persons with YOD and 98 with LOD were included. No significant differences in QoL were detected. Determinants of QoL were similar in YOD and LOD. Behavioral and psychological symptoms of dementia (BPSD), suffering and other distressing symptoms were associated with a lower QoL. In YOD but not in LOD antipsychotic treatment was associated with low QoL. The group of persons who were younger than 65 years at the time of the study visit experienced significantly more distressing symptoms than older PWAD.

Conclusion:

Overall, persons with advanced YOD do not appear to be disadvantaged compared to old and oldest PWAD. Special attention, however, must be paid to the group of the very young persons who seem to be particularly vulnerable.

Ocular Neurodegenerative Diseases: Interconnection between Retina and Cortical Areas

The possible interconnection between the eye and central nervous system (CNS) has been a topic of discussion for several years just based on fact that the eye is properly considered an extension of the brain. Both organs consist of neurons and derived from a neural tube. The visual process involves photoreceptors that receive light stimulus from the external environment and send it to retinal ganglionic cells (RGC), one of the cell types of which the retina is composed. The retina, the internal visual membrane of the eye, processes the visual stimuli in electric stimuli to transfer it to the brain, through the optic nerve. Retinal chronic progressive neurodegeneration, which may occur among the elderly, can lead to different disorders of the eye such as glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR). Mainly in the elderly population, but also among younger people, such ocular pathologies are the cause of irreversible blindness or impaired, reduced vision. Typical neurodegenerative diseases of the CSN are a group of pathologies with common characteristics and etiology not fully understood; some risk factors have been identified, but they are not enough to justify all the cases observed. Furthermore, several studies have shown that also ocular disorders present characteristics of neurodegenerative diseases and, on the other hand, CNS pathologies, i.e., Alzheimer disease (AD) and Parkinson disease (PD), which are causes of morbidity and mortality worldwide, show peculiar alterations at the ocular level. The knowledge of possible correlations could help to understand the mechanisms of onset. Moreover, the underlying mechanisms of these heterogeneous disorders are still debated. This review discusses the characteristics of the ocular illnesses, focusing on the relationship between the eye and the brain. A better comprehension could help in future new therapies, thus reducing or avoiding loss of vision and improve quality of life.

Current Alzheimer disease research highlights: evidence for novel risk factors

Alzheimer disease (AD) is the most common type of dementia characterized by the progressive cognitive and social decline. Clinical drug targets have heavily focused on the amyloid hypothesis, with amyloid beta (Aβ), and tau proteins as key pathophysiologic markers of AD. However, no effective treatment has been developed so far, which prompts researchers to focus on other aspects of AD beyond Aβ, and tau proteins. Additionally, there is a mounting epidemiologic evidence that various environmental factors influence the development of dementia and that dementia etiology is likely heterogenous. In the past decades, new risk factors or potential etiologies have been widely studied. Here, we review several novel epidemiologic and clinical research developments that focus on sleep, hypoxia, diet, gut microbiota, and hearing impairment and their links to AD published in recent years. At the frontiers of AD research, these findings and updates could be worthy of further attention.

An Integrative Literature Review on the Nomenclature and Definition of Dementia at a Young Age

Background:

There has been growing interest in young people living with dementia. Future research requires consensus on the terminology and operational definition of this group.

Objective:

The purpose of this integrative review was to explore and include all operational definitions used to define dementia at a young age.

Methods:

On August 14, 2020, the PubMed, Embase, Cinahl, and PsycInfo databases were searched for empirical and theoretical literature using Google. Various terms to describe and define ‘dementia’ and ‘at a young age’ were used to collect literature concerning terminology; age-related aspects, including cut-off ages and criteria; and etiologies of dementia at a young age.

Results:

The search yielded 6,891 empirical and 4,660 theoretical publications, resulting in the inclusion of 89 publications, including 36 publications containing an explicit discussion and 53 publications as confirmation. ‘Young-onset dementia’ was the most commonly used term of seven identified terms, in the last two decades. The age of 65 years at symptom onset was used most frequently when considering a total of six upper age limits and four criteria to define a cut-off age. Eight lower age limits and an option for subdivision based on age were included. We identified 251 different etiologies and 27 categories of etiologies.

Conclusion:

Despite relative consensus on the term young-onset dementia and an age at symptom onset being used as a cut-off criterion, much is still unclear concerning possible etiologies of dementia at a young age. In the current study, controversies were detected for discussion in an international consensus study.

Discovery of Novel Markers for Identifying Cognitive Decline Using Neuron-Derived Exosomes

Alzheimer's disease (AD), the predominant cause of late-life dementia, has a multifactorial etiology. Since there are few therapeutic options for symptomatic AD, research is increasingly focused on the identification of pre-symptomatic biomarkers. Recently, evaluation of neuron-derived exosomal markers has emerged as a promising novel approach for determining neuronal dysfunction. We aimed to identify novel neuron-derived exosomal markers that signify a transition from normal aging to Mild Cognitive Impairment (MCI) and then to clinically established AD, a sequence we refer to as AD progression. By using a Tandem Mass Tag-based quantitative proteomic approach, we identified a total of 360 neuron-derived exosomal proteins. Subsequent fuzzy c-means clustering revealed two clusters of proteins displaying trends of gradually increasing/decreasing expression over the period of AD progression (normal to MCI to AD), both of which were mainly involved in immune response-associated pathways, proteins within these clusters were defined as bridge proteins. Several differentially expressed proteins (DEPs) were identified in the progression of AD. The intersections of bridge proteins and DEPs were defined as key proteins, including C7 (Complement component 7), FERMT3 (Fermitin Family Member 3), CAP1 (Adenylyl cyclase-associated protein 1), ENO1 (Enolase 1), and ZYX (Zyxin), among which the expression patterns of C7 and ZYX were almost consistent with the proteomic results. Collectively, we propose that C7 and ZYX might be two novel neuron-derived exosomal protein markers, expression of which might be used to evaluate cognitive decline before a clinical diagnosis of AD is warranted.

What is the gold standard model for Alzheimer's disease drug discovery and development?

Introduction: Alzheimer's disease models (ADMs) are currently used for drug development (DD). More than 20,000 molecules were screened for AD treatment over decades, with only one drug (Aducanumab)FDA-approved over the past 18 years. A revision of pathogenic concepts and ADMs are needed.Areas covered: The authors discuss herein preclinical models including: (i) in vitro models (cell lines, primary neuron cell cultures, iPSC-derived brain cells), (ii) ex vivo models, and (iii) in vivo models (artificial, transgenic, non-transgenic and induced).Expert opinion: The following types of ADMs have been reported: Mouse models (45.08%), Rat models (15.04%), Non-human Primate models (0.76%), Rabbit models (0.46%), Cat models (0.53%), Pig models (0.30%), Guinea pig models (0.15%), Octodon degu models (0.02%), Dog models (0.54%), Drosophila melanogaster models (1.79%), Zebrafish models (0.50%), Caenorhabditis elegans (1.21%), Cell culture models (3.31%), Cholinergic models (8.26%), Neurotoxic models (6.79%), Neuroinflammation models (6.92%), Neurovascular models (7.88%), and Microbiome models (0.45%).No single ADM faithfully reproduces all the pathogenic events in the human AD phenotype spectrum. ADMs should be different for (i) pathogenic studies vs basic DD, and (ii) preventive interventions vs symptomatic treatments. There cannot be an ideal ADM for DD, because AD is a spectrum of syndromes. DD can integrate pathogenic, mechanistic, metabolic, transporter and pleiotropic genes in a multisystem model.

Effects of Photobiomodulation on Changes in Cognitive Function and Regional Cerebral Blood Flow in Patients with Mild Cognitive Impairment: A Pilot Uncontrolled Trial

BACKGROUND

Photobiomodulation (PBM) affects local blood flow regulation through nitric oxide generation, and various studies have reported on its effect on improving cognitive function in neurodegenerative diseases. However, the effect of PBM in the areas of the vertebral arteries (VA) and internal carotid arteries (ICA), which are the major blood-supplying arteries to the brain, has not been previously investigated.

OBJECTIVE

We aimed to determine whether irradiating PBM in the areas of the VA and ICA, which are the major blood-supplying arteries to the brain, improved regional cerebral blood flow (rCBF) and cognitive function.

METHODS

Fourteen patients with mild cognitive impairments were treated with PBM. Cognitive assessment and single-photon emission computed tomography were implemented at the baseline and at the end of PBM.

RESULTS

Regarding rCBF, statistically significant trends were found in the medial prefrontal cortex, lateral prefrontal cortex, anterior cingulate cortex, and occipital lateral cortex. Based on the cognitive assessments, statistically significant trends were found in overall cognitive function, memory, and frontal/executive function.

CONCLUSION

We confirmed the possibility that PBM treatment in the VA and ICA areas could positively affect cognitive function by increasing rCBF. A study with a larger sample size is needed to validate the potential of PBM.

The efficacy of the picture version of the free and cued selective reminding test to detect significant neurocognitive deficits in a Chilean population

The picture version of the Free and cued selective reminding test with immediate recall is a test adept at measuring the memory encoding and the effect of semantic cues. Furthermore, it is sensitive to detect early dementia stages. This study aimed to obtain psychometric properties of visual Buschke and Grober The Free and Cued Selective Reminding Test (FCSRT) in healthy older adults, mild neurocognitive disorders, and major neurocognitive subjects on a Chilean population.

METHOD

226 participants were included, 113 healthy older adults (HOA), 65 mild neurocognitive disorder (NCD) subjects, and 48 major NCD. Each individual was assessed with the same protocol.

RESULTS

The observed area under the curve (AUC) was higher than .90 in all the FCSRT measures in the major cognitive disorders and healthy older people.

CONCLUSION

according to the AUCs, it was shown that Free Recall, Sensitivity to Cueing Index, and Delay Recall of the FCSRT are suitable to detect major neurocognitive disorders.

Evaluation of γ-carboline-phenothiazine conjugates as simultaneous NMDA receptor blockers and cholinesterase inhibitors

Alzheimer's disease (AD) is the most common form of dementia. It is associated with the impairment of memory and other cognitive functions that are mainly caused by progressive defects in cholinergic and glutamatergic signaling in the central nervous system. Inhibitors of acetylcholinesterase (AChE) and ionotropic glutamate receptors of the N-methyl-d-aspartate (NMDA) receptor family are currently approved as AD therapeutics. We previously showed using a cell-based assay of NMDA receptor-mediated glutamate-induced excitotoxicity that bis-γ-carbolinium conjugates are useful NMDA receptor blockers. However, these compounds also act as subnanomolar AChE inhibitors, which may cause serious anticholinergic side effects when applied in vivo. Here, we evaluated new structures containing γ-carbolines linked to phenothiazine via a propionyl spacer. These compounds were superior to the previously characterized bis-γ-carbolinium conjugates because they blocked NMDA receptors without requiring a quaternary pyridine N-atom and inhibited AChE with moderate IC₅₀ values of 0.54-5.3 µM. In addition, these new compounds displayed considerable selectivity for the inhibition of butyrylcholinesterase (BChE; IC₅₀ = 0.008-0.041 µM), which may be favorable for AD treatment. Inhibitory activities towards the NMDA receptors and AChE were in the same micromolar range, which may be beneficial for equal dosing against multiple targets in AD patients.

Global trends in symptomatic medication use against dementia in 66 countries/regions from 2008 to 2018

BACKGROUND AND PURPOSE

The aim was to determine trends and patterns of symptomatic medication used against dementia in 66 countries and regions.

METHODS

This was a cross-sectional study that used the wholesale data from the IQVIA Multinational Integrated Data Analysis System database. Sale data for symptomatic medication against dementia from 66 countries and regions from 2008 to 2018 were analysed and stratified by income level (low/middle-income countries [LMICs], n = 27; high-income countries [HICs], n = 37; regions, n = 2). The medication use volume was estimated by defined daily dose (DDD) per 1000 inhabitants per day (World Health Organization DDD harmonized the size, strength and form of each pack and reflects average dosing). Changes in medication use over time were quantified as percentage changes in compound annual growth rates (CAGRs).

RESULTS

Total symptomatic medication against dementia sales increased from 0.85 to 1.33 DDD per 1000 inhabitants per day between 2008 and 2018 (LMICs 0.094-0.396; HICs 3.88-5.04), which is an increase of CAGR of 4.53% per year. The increase was mainly driven by the LMICs (CAGR = 15.42%) in comparison to the HICs (CAGR = 2.65%). The overall medication use from 2008 to 2018 increased for all four agents: memantine (CAGR = 8.51%), rivastigmine (CAGR = 6.91%), donepezil (CAGR = 2.72%) and galantamine (CAGR = 0.695%). In 2018, the most commonly used medication globally was donepezil, contributing to 49.8% of total use volume, followed by memantine (32.7%), rivastigmine (11.24%) and galantamine (6.36%).

CONCLUSION

There was an increasing trend in the use of symptomatic medications against dementia globally, but the use remained low in LMICs. Interventions may be needed to support the medication use in some countries.

Association Between the Prognostic Nutritional Index and Cognitive Function Among Older Adults in the United States: A Population-Based Study

BACKGROUND

Nutritional status has been recognized as an important factor influencing cognitive function-related diseases, but few comprehensive nutrition indicators are available to assess the risk of cognitive decline.

OBJECTIVE

This study aimed to investigate the relationship between the prognostic nutritional index (PNI) and cognitive function in an elderly population, and the differences in nutrient intake between different levels of nutritional risk.

METHODS

Based on cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014, we included 2,564 older participants. The lower quartile of each of the four cognitive tests was considered to have cognitive function impairment (CFI). Binary and multivariate logistic regression models were used to estimate the relationship between the PNI and the odds ratio of CFI.

RESULTS

After adjustment for confounding variables, we found that the odds of CFI were significantly lower for participants with normal PNI levels than for those with low PNI levels. In a comparison of global cognitive impairment scores, participants with a normal PNI had lower ratios of poor cognitive performance than those with a low PNI. By comparing the nutrient intake at different PNI levels, we found a reduction in the intake of protein, dietary fiber, total saturated fatty acids, and multiple micronutrients in the low PNI group.

CONCLUSION

Our study shows that the PNI can be a good predictor of the odds of CFI in the elderly population and that it is a convenient indicator of reduced intake of nutrients which may be important to brain health.

Ginkgo Biloba Extract Is Comparable With Donepezil in Improving Functional Recovery in Alzheimer's Disease: Results From a Multilevel Characterized Study Based on Clinical Features and Resting-State Functional Magnetic Resonance Imaging

Background: Ginkgo biloba extract (GBE) and donepezil have been reported to be effective in patients with Alzheimer's disease (AD). Nonetheless, how these drugs impact spontaneous brain activities and how they consequently improve functional recovery are currently unclear. Objectives: This study was to explore the efficacy of GBE vs. donepezil and their add-on efficacy on functional recovery and the adaption of spontaneous brain activities following pharmacologic treatment in patients with AD. Methods: Patients with AD were enrolled and assigned to the GBE group (n = 50), the donepezil group (n = 50), or the combined group (n = 50). Neuropsychological assessments, including minimum mental state examination (MMSE), Alzheimer's disease assessment scale-cognition (ADAS-Cog), instrumental activity of daily living (IADL), geriatric depression scale (GDS), neuropsychiatric inventory (NPI), and quality of life in Alzheimer's disease (QOL-AD), were conducted at baseline, 1 month, 3 months, and 6 months. Resting-state functional magnetic resonance imaging (rs-fMRI) was collected to compare the amplitude of low-frequency fluctuation (ALFF), percent amplitude of fluctuation (PerAF), regional homogeneity (ReHo), and degree centrality (DC) at baseline and 6 months. Results: No major significant differences were detected in all comparisons between groups across all follow-up time points. For intragroup comparison, MMSE and ADAS-Cog scores differed significantly across all follow-ups in three groups. The combined group showed significant improvement of GDS scores between baseline and 6 months (p = 0.007). The GBE group (p = 0.044) and donepezil group (p = 0.012) demonstrated significant improvement of NPI scores between baseline and 6 months. Significant correlations were observed between IADL and ALFF in the right gyrus rectus (p = 0.03) and in the left superior cerebellum gyrus (p = 0.01), between GDS and ALFF in the right middle temporal gyrus (p = 0.01), between NPI and PerAF in the left fusiform gyrus (p = 0.03), and between MMSE and ReHo in right superior frontal gyrus (p = 0.04). Conclusion: GBE was comparable with donepezil in the improvement of functional recovery in patients with AD while the combined application of GBE and donepezil seems unnecessary. GBE-mediated improvement of functional recovery was characterized by decreased ALFF values in the right gyrus rectus and decreased PerAF values in the left fusiform gyrus. These featured variations of imaging metrics in specific brain regions may serve as biomarkers in the monitoring of the therapeutic efficacy of GBE.

Obstructive Sleep Apnea: Cognitive Outcomes

There is a strong association between obstructive sleep apnea (OSA) and cognitive dysfunction. Executive function, attention, verbal/visual long-term memory, visuospatial/constructional ability, and information processing are more likely to be affected, whereas language, psychomotor function, and short-term memory are less likely to be affected. Increased accumulation of Aß₂-amyloid in the brain, episodic hypoxemia, oxidative stress, vascular inflammation, and systemic comorbidities may contribute to the pathogenesis. Patients with OSA should have cognitive screening or formal testing, and patients with cognitive decline should have testing for OSA. Treatment with continuous positive airway pressure may improve cognitive symptoms in the patient with OSA.

The psychological impact on patients with memory disorders and their caregivers during COVID-19

BACKGROUND

COVID-19 is erupting globally. Mass quarantine had been implemented all around China which could influence the psychological status of patients with memory disorders and their caregivers.

AIM

To investigate the psychological impact of mass quarantine on patients with memory disorders and their caregivers in China.

METHODS

We completed a cross-sectional study in 787 patients and their caregivers registered from 2010 to 2019 in Memory Clinic, The First Affiliated Hospital of Chongqing Medical University, by telephone interviews. The performance in neuropsychiatric symptoms (NPSs), sleep, nutrition, chronic diseases of patients, and the burden of care, anxiety and depression of caregivers was assessed by six assessment scales (MNA-SF, PSQI, NPI, RSS, PHQ-9 and GAD-7).

RESULTS

Only 68 (8.6%) patients worried about the outbreak of COVID-19. The prevalence of NPSs among all subjects was nearly 60.0%. Approximately 50.0% of the caregivers reported distress. More than 70.0% of patients remained stable in NPSs. However, anxiety, depression, aberrant motor disorder and delusion were exacerbated (22.9%, 18.6%, 17.1% and 16.8%, respectively). Appetite and eating disorder led alleviation rate by 25.8% while disappearing rate of agitation led by 5.8%. 7.5% of caregivers manifested depressive symptoms while 4.9% expressed anxiety symptoms, and 40.8% showed care burden. The coefficients of RSS and PHQ-9, RSS and GAD-7, RSS and NPI-D, PHQ-9 and GAD-7 were 0.7, 0.5, 0.5 and 0.6, respectively (p < 0.01).

CONCLUSION

Changes in NPSs during COVID-19 were observed in some patients with memory disorders and their caregivers, and adherence to medication contributed to the stabilization of NPSs.

Vagus nerve stimulation in brain diseases: Therapeutic applications and biological mechanisms

Brain diseases, including neurodegenerative, cerebrovascular and neuropsychiatric diseases, have posed a deleterious threat to human health and brought a great burden to society and the healthcare system. With the development of medical technology, vagus nerve stimulation (VNS) has been approved by the Food and Drug Administration (FDA) as an alternative treatment for refractory epilepsy, refractory depression, cluster headaches, and migraines. Furthermore, current evidence showed promising results towards the treatment of more brain diseases, such as Parkinson's disease (PD), autistic spectrum disorder (ASD), traumatic brain injury (TBI), and stroke. Nonetheless, the biological mechanisms underlying the beneficial effects of VNS in brain diseases remain only partially elucidated. This review aims to delve into the relevant preclinical and clinical studies and update the progress of VNS applications and its potential mechanisms underlying the biological effects in brain diseases.

Incidence of dementia after dengue fever: Results of a longitudinal population-based study

OBJECTIVE

To investigate the epidemiological relationship between dengue fever and the subsequent development of dementia.

METHODS

Using nationwide Taiwan registries from the National Health Insurance Research (NHIRD), we identified adults aged over 40 years who received a dengue fever diagnosis from 1 January 2000 to 31 December 2012 and who did not have a history of dementia. We used a propensity score match (PSM) to balance the baseline characteristics between groups. All eligible adults were sorted into either the dengue group or non-dengue group at a ratio of 1:4, matching by age, sex, index years, income level, and relevant comorbidities. Using Cox regression with proportional hazards models, we estimated the risk of dementia. The study period started from 1 January 2000 to 31 December 2013. We conducted sensitivity analyses to cross-validate study results.

RESULTS

With a median of 8.01 years of follow-up, patients in the dengue group were more at risk of developing dementia than the non-dengue group. The estimated cumulative incidence of dementia was 7.21% in the dengue group and 4.03% in the non-dengue group (adjusted hazard ratio (aHR), 1.71; 95% CI, 1.03 to 2.83). Sensitivity analyses yielded consistent findings. We excluded any stroke cases before the end of the study, and subgroup analysis by follow-up time showed that the dengue group has a significantly higher risk of new-onset dementia >6 years after the index date (aHR 3.24; 95% CI, 1.42 to 7.37). The P value for interaction was significant (<.0001).

CONCLUSIONS

This study demonstrated a significantly higher risk of dementia in patients with dengue fever in Taiwan than in those without dengue fever.

Physiologic Frailty and Neurocognitive Decline Among Young-Adult Childhood Cancer Survivors: A Prospective Study From the St Jude Lifetime Cohort

PURPOSE

Eight percent of young-adult childhood cancer survivors meet criteria for frailty, an aging phenotype associated with poor health. In the elderly general population, frailty is associated with neurocognitive decline; this association has not been examined in adult survivors of childhood cancer.

METHODS

Childhood cancer survivors 18-45 years old (≥ 10 years from diagnosis) were clinically evaluated for prefrailty or frailty (respectively defined as ≥ 2 or ≥ 3 of: muscle wasting, muscle weakness, low energy expenditure, slow walking speed, and exhaustion [Fried criteria]) and completed neuropsychologic assessments at enrollment (January 2008-June 2013) and 5 years later. Weighted linear regression using inverse of sampling probability estimates as weights compared differences in neurocognitive decline in prefrail and frail survivors versus nonfrail survivors, adjusting for diagnosis age, sex, race, CNS-directed therapy (cranial radiation, intrathecal chemotherapy, and neurosurgery), and baseline neurocognitive performance.

RESULTS

Survivors were on average 30 years old and 22 years from diagnosis; 18% were prefrail and 6% frail at enrollment. Frail survivors declined an average of 0.54 standard deviation (95% CI, -0.93 to -0.15) in short-term verbal recall, whereas nonfrail survivors did not decline (β = .22; difference of βs = -.76; 95% CI, -1.19 to -0.33). Frail survivors declined more than nonfrail survivors on visual-motor processing speed (β = -.40; 95% CI, -0.67 to -0.12), cognitive flexibility (β = -.62; 95% CI, -1.02 to -0.22), and verbal fluency (β = -.23; 95% CI, -0.41 to -0.05). Prefrail and frail survivors experienced greater declines in focused attention (prefrail β = -.35; 95% CI, -0.53 to -0.17; frail β = -.48; 95% CI, -0.83 to -0.12) compared with nonfrail survivors.

CONCLUSION

Over approximately 5 years, prefrail and frail young-adult survivors had greater declines in cognitive domains associated with aging and dementia compared with nonfrail survivors. Interventions that have global impact, designed to target the mechanistic underpinnings of frailty, may also mitigate or prevent neurocognitive decline.

On the prevention and treatment of Alzheimer's disease: Control the promoters and look beyond the brain

Alzheimer's disease (AD) is a progressive incurable neurodegenerative disease of the brain afflicting a third of the population aged 85 and older. Pathologic hallmarks include extracellular plaques of amyloid-beta (Aß), intraneuronal neurofibrillary tangles of hyperphosphorylated tau protein, synaptic destruction, neuronal death, and brain atrophy. Neuroinflammation, mediated by microglia, is a central component of the disease, and is intricately connected with peripheral inflammation. The clinical manifestations include progressive memory loss and eventual death. The present treatment of AD is largely ineffective. Nearly all AD is late-onset and presents age 65 or older, and the most common genetic risk factor is carriage of an apolipoprotein (APO) E4 allele, seen in about 25% of the general population. Individuals carrying an APOE4 allele produce more Aß and clear it less efficiently from the brain throughout life. There has been accumulating pathologic and clinical evidence that microbes, particularly the herpes simplex virus (HSV), is a causative factor for AD, most notable in carriers of the APOE4 allele. Eighty percent of the adult population harbors HSV and it resides in the trigeminal ganglion in latent state throughout life, but periodically reactivates, traveling antegrade resulting in herpes labialis and traveling retrograde into the brain leading to neuroinflammation. Functioning as an antimicrobial peptide, Aß inactivates HSV and the recurring process culminates in a buildup of Aß plaque and other hallmarks of AD over time. Periodontal disease exists in 20-50% of the adult population and is also a causative factor for AD. Accordingly, bacteria causing periodontal disease and their byproducts can enter the brain directly via the trigeminal nerve or indirectly through the bloodstream, resulting in AD pathology over time. There are many other promoters of AD, particularly inflammatory conditions outside of the brain, that can be mitigated. Small trials are finally in progress testing antimicrobial drugs for the prevention and treatment of AD. In the meantime, a more proactive approach to the prevention and treatment of AD is posited, with an emphasis on prevention, since the pathologic underpinnings of the disease start decades before the clinical manifestations. Individuals can be stratified in risk categories using family history, periodontal disease presence, APOE4 carriage, and HSV IgG positivity. Moderate- and high-risk individuals can be treated safely with various preventive measures and appropriate antimicrobial agents as discussed. Importantly, the proposed treatments are concordant with the accepted practice of medicine, and if utilized, could significantly decrease AD prevalence.

Neurological Mechanisms of Animal-Assisted Intervention in Alzheimer's Disease: A Hypothetical Review

Alzheimer's disease (AD) is an irreversible neurodegenerative brain disorder with aggregation of amyloid-beta (Aβ) and tau as the pathological hallmarks. AD is the most common form of dementia and is characterized by a progressive decline of cognition. The failure of pharmacological approaches to treat AD has resulted in an increased focus on non-pharmacological interventions that can mitigate cognitive decline and delay disease progression in patients with AD. Animal-assisted intervention (AAI), a non-pharmacological intervention, improves emotional, social, and cognitive dysfunction in patients with neurodegenerative diseases. In particular, AAI is reported to mitigate the effects of cognitive impairment in patients with AD. Despite the positive effects of AAI on cognitive dysfunction in patients with AD, there have been no studies on how AAI affects AD-related pathologies. This review postulates potential neurological mechanisms of emotional or social interaction through AAI in countering AD-related pathologies, such as Aβ deposition, tau hyperphosphorylation, neuroinflammation, and impaired adult hippocampal neurogenesis (AHN), and proposes insights for future research by organizing accumulated previous evidence.

A Cumulative Muscle Index and Its Parameters for Predicting Future Cognitive Decline: Longitudinal Outcomes of the ASPRA Cohort

Sarcopenia and cognitive decline share the major risk factors of physical inactivity; previous studies have shown inconsistent associations. We aimed to identify the association of sarcopenia and its parameters with cognitive decline. The 3-year longitudinal outcomes of 1327 participants from the Aging Study of the Pyeongchang Rural Area (ASPRA) cohort were analyzed. Cognitive performance was evaluated using the Mini-Mental State Examination (MMSE), and sarcopenia was defined by the following: the original and revised Asian Working Group for Sarcopenia (AWGS), the original and revised European Working Group on Sarcopenia in Older People (EWGSOP), and the Cumulative Muscle Index (CMI), a novel index based on the number of impaired domains of sarcopenia. Approximately half of the participants showed meaningful cognitive decline. Sarcopenia by the original EWGSOP and the CMI were associated with cognitive decline. Only the CMI showed consistent predictability for cognitive impairment even with different criteria of the MMSE score (OR 1.23 [1.04-1.46]; OR 1.34 [1.12-1.59]; OR 1.22 [1.01-1.49], using the 1, 2, and 3 cut-off value, respectively). Of the CMI parameters, gait speed was satisfactorily predictive of 3-year cognitive impairment (OR 0.54 [0.30-0.97]). In conclusion, sarcopenia based on the CMI may be predictive of future cognitive impairment. Gait speed was the single most important indicator of cognitive decline.

Parkinson disease-associated cognitive impairment

Parkinson disease (PD) is the second most common neurodegenerative disorder, affecting >1% of the population ≥65 years of age and with a prevalence set to double by 2030. In addition to the defining motor symptoms of PD, multiple non-motor symptoms occur; among them, cognitive impairment is common and can potentially occur at any disease stage. Cognitive decline is usually slow and insidious, but rapid in some cases. Recently, the focus has been on the early cognitive changes, where executive and visuospatial impairments are typical and can be accompanied by memory impairment, increasing the risk for early progression to dementia. Other risk factors for early progression to dementia include visual hallucinations, older age and biomarker changes such as cortical atrophy, as well as Alzheimer-type changes on functional imaging and in cerebrospinal fluid, and slowing and frequency variation on EEG. However, the mechanisms underlying cognitive decline in PD remain largely unclear. Cortical involvement of Lewy body and Alzheimer-type pathologies are key features, but multiple mechanisms are likely involved. Cholinesterase inhibition is the only high-level evidence-based treatment available, but other pharmacological and non-pharmacological strategies are being tested. Challenges include the identification of disease-modifying therapies as well as finding biomarkers to better predict cognitive decline and identify patients at high risk for early and rapid cognitive impairment.

Trajectory patterns of blood pressure change up to six years and the risk of dementia: a nationwide cohort study

The present study aimed to investigate the associations between the trajectory of blood pressure (BP) change and the risk of subsequent dementia and to explore the differences in age, gender, and hypertension subgroups. We included 10,660 participants aged ≥ 60 years from 1998 to 2018 waves of the Chinese Longitudinal Healthy Longevity Survey. Latent growth mixture models were used to estimate BP trajectories. Cox-proportional hazard models were used to analyze the effects of BP trajectories on the risk of dementia. According to the results, stabilized systolic BP (SBP) was found to be associated with a higher risk of dementia compared with normal SBP [adjusted hazard ratio (aHR): 1.62; 95% confidence interval (CI): 1.27-2.07] and elevated SBP (aHR: 2.22; 95% CI: 1.51-3.28) in and only in the subgroups of the oldest-old, women, and subjects without hypertension at baseline. Similarly, stabilized pulse pressure (PP) was associated with a higher risk of dementia compared with normal PP (aHR: 1.52; 95% CI: 1.24-1.88) and elevated PP (aHR: 2.12; 95% CI: 1.48-3.04) in and only in the subgroups of the oldest-old, women, and subjects with hypertension at baseline. These findings suggest that stabilized SBP and PP have predictive significance for the occurrence of dementia in late life, and the factors of age, gender, and late-life hypertension should be considered when estimating the risk of BP decline on dementia.

Discrepancies in persons with dementia, family members, and physician perspectives of dementia treatment: a descriptive study

BACKGROUND

This study aims to reconsider diagnostic approaches to dementia where pharmacological approaches are not available to reverse the pathological changes caused by dementia.

METHODS

A questionnaire survey was conducted with 524 physicians specialising in dementia management in Aichi, Japan, with 163 (31.1%) valid responses. The survey gathered information on the perceived merits and demerits of the early diagnosis of dementia and the priorities in treating those with mild cognitive impairment (MCI), mild dementia, and moderate or advanced dementia. In the interview survey, 27 outpatients with mild Alzheimer's disease (76.2 ± 7.6 years old; Mini-Mental State Examination score 23.3 ± 2.7 points; 21 women, six men) and 24 family members (12 spouses, 12 children) were asked about their priorities in treatment.

RESULTS

A total of 61.3% of physicians answered that persons with dementia having more time to accept the diagnosis is a merit of early diagnosis, while 61.3% answered that the possibility of causing anxiety was a demerit. Around 45% of the physicians chose the option 'maintaining cognitive function' as the first priority in cases of MCI and mild dementia, while 39.3% considered it the last priority in moderate or advanced cases. About 22.2% of persons with dementia and 37.5% of their families assigned the highest priority to 'maintaining cognitive function', whereas 37.0% of persons with dementia prioritised 'maintaining quality of life for them and their families'.

CONCLUSIONS

Although it is important to build therapeutic alliances among persons with dementia, their families, and physicians by sharing a common perspective for better treatment of dementia, this study suggested that the three parties do not always share the same vision. Future research is needed to determine how to build therapeutic alliances for better approaches to dementia, especially to ensure that timely diagnosis is beneficial for persons with dementia and their families.

Key role of the CCR2-CCL2 axis in disease modification in a mouse model of tauopathy

BACKGROUND

For decades, dementia has been characterized by accumulation of waste in the brain and low-grade inflammation. Over the years, emerging studies highlighted the involvement of the immune system in neurodegenerative disease emergence and severity. Numerous studies in animal models of amyloidosis demonstrated the beneficial role of monocyte-derived macrophages in mitigating the disease, though less is known regarding tauopathy. Boosting the immune system in animal models of both amyloidosis and tauopathy, resulted in improved cognitive performance and in a reduction of pathological manifestations. However, a full understanding of the chain of events that is involved, starting from the activation of the immune system, and leading to disease mitigation, remained elusive. Here, we hypothesized that the brain-immune communication pathway that is needed to be activated to combat tauopathy involves monocyte mobilization via the C-C chemokine receptor 2 (CCR2)/CCL2 axis, and additional immune cells, such as CD4⁺ T cells, including FOXP3⁺ regulatory CD4⁺ T cells.

METHODS

We used DM-hTAU transgenic mice, a mouse model of tauopathy, and applied an approach that boosts the immune system, via blocking the inhibitory Programmed cell death protein-1 (PD-1)/PD-L1 pathway, a manipulation previously shown to alleviate disease symptoms and pathology. An anti-CCR2 monoclonal antibody (αCCR2), was used to block the CCR2 axis in a protocol that partially eliminates monocytes from the circulation at the time of anti-PD-L1 antibody (αPD-L1) injection, and for the critical period of their recruitment into the brain following treatment.

RESULTS

Performance of DM-hTAU mice in short-term and working memory tasks, revealed that the beneficial effect of αPD-L1, assessed 1 month after a single injection, was abrogated following blockade of CCR2. This was accompanied by the loss of the beneficial effect on disease pathology, assessed by measurement of cortical aggregated human tau load using Homogeneous Time Resolved Fluorescence-based immunoassay, and by evaluation of hippocampal neuronal survival. Using both multiparametric flow cytometry, and Cytometry by Time Of Flight, we further demonstrated the accumulation of FOXP3⁺ regulatory CD4⁺ T cells in the brain, 12 days following the treatment, which was absent subsequent to CCR2 blockade. In addition, measurement of hippocampal levels of the T-cell chemoattractant, C-X-C motif chemokine ligand 12 (Cxcl12), and of inflammatory cytokines, revealed that αPD-L1 treatment reduced their expression, while blocking CCR2 reversed this effect.

CONCLUSIONS

The CCR2/CCL2 axis is required to modify pathology using PD-L1 blockade in a mouse model of tauopathy. This modification involves, in addition to monocytes, the accumulation of FOXP3⁺ regulatory CD4⁺ T cells in the brain, and the T-cell chemoattractant, Cxcl12.

Dose-Response Relationship Between Long-Term Blood Pressure Variability and Cognitive Decline

BACKGROUND AND PURPOSE

We aimed to test whether higher long-term blood pressure variability was associated with accelerated rate of cognitive decline and evaluate potential dose-response relationship.

METHODS

Original survey data from the Health and Retirement Study and the English Longitudinal Study of Ageing were used. Standardized Z score of cognitive function was the main outcome measure. Visit-to-visit blood pressure SD, coefficient of variation, and variation independent of mean were used. Linear mixed model and restricted spline were applied to assess association and explore dose-response pattern. Segmented regression was used to analyze dose-response relationship and estimate turning point. Meta-analysis using random-effects model was conducted to pool results, with I² used to test heterogeneity.

RESULTS

A total of 12 298 dementia-free participants were included (mean age: 64.6±8.6 years). Significant association was observed between blood pressure variability and cognitive decline. Each 10% increment in coefficient of variation of systolic and diastolic blood pressure was associated with accelerated global cognitive decline of 0.026 SD/y (95% CI, 0.016-0.036, P<0.001) and 0.022 SD/y (95% CI, 0.017-0.027, P<0.001), respectively. Nonlinear dose-response relationship was found (P<0.001 for nonlinearity), with clear turning point observed (P<0.001 for change in slopes).

CONCLUSIONS

Higher long-term blood pressure variability was associated with accelerated cognitive decline among general adults aged ≥50 years, with nonlinear dose-response relationship. Further randomized controlled trials are warranted to evaluate potential benefits of blood pressure variability-lowering strategies from a cognitive health perspective.

Blood pressure variability and cognitive dysfunction: A systematic review and meta-analysis of longitudinal cohort studies

The variability of blood pressure (BPV) has been suggested as a clinical indicator for cognitive dysfunction, yet the results from clinical studies are variable. This study investigated the relationship between BPV and the risk of cognitive decline or dementia. Bibliographic databases, including PubMed, Scopus, and Embase, were searched systematically for longitudinal cohort studies with BPV measurements and neuropsychological examinations or dementia diagnosis. A traditional meta‐analysis with subgroup analysis, and a further dose‐response meta‐analysis were conducted. Twenty cohort studies with 7 924 168 persons were included in this review. The results showed that a higher systolic BPV (SBPV), when measured with the coefficient of variation (SBP‐CV) or standard deviation (SBP‐SD), was associated with a higher risk of all‐cause dementia diagnosis but not incidence of cognitive decline on neuropsychological examinations. In subgroup analysis, the effect was more prominent when using BPV of shorter timeframes, during shorter follow‐ups, or among the elderly aged more than 65 years. No dose‐response relationship could be found. Our study suggested possible positive associations between SBPV and the risk of dementia. Further studies are required to validate these findings.

Contribution of the Cognitive Approach to Language Assessment to the Differential Diagnosis of Primary Progressive Aphasia

Diagnosis of primary progressive aphasia (PPA) is essentially based on the identification of progressive impairment of language abilities while other cognitive functions are preserved. The three variants of PPA are characterized by core and supportive clinical features related to the presence or absence of language impairment in different linguistic domains. In this article, we review the cognitive neuropsychological approach to the assessment of PPA and its contribution to the differential diagnosis of the three variants. The main advantage of this assessment approach is that it goes beyond the mere description and classification of clinical syndromes and identifies impaired and preserved cognitive and linguistic components and processes. The article is structured according to the main language domains: spoken production, language comprehension, and written language. Each section includes a brief description of the cognitive processes involved in the assessment tasks, followed by a discussion of typical characteristics for each PPA variant and common pitfalls in the interpretation of the results. In addition, the clinical benefit of the cognitive neuropsychological approach for the behavioral management of PPA is briefly sketched out in the conclusion.

Subcommissural Organ-Spondin-Derived Peptide Restores Memory in a Mouse Model of Alzheimer's Disease

Alzheimer’s disease (AD) is a devastating neurodegenerative disease that affects millions of older people worldwide and is characterized by a progressive deterioration of cognitive functions, including learning and memory. There are currently very few approved treatments (i.e., acetylcholinesterase inhibitors such as donepezil), all of which are limited to the symptomatic control of AD and are associated with side effects that may result in discontinuation of treatment. Therefore, there is an urgent need to develop disease-modifying treatments to prevent AD-induced cognitive deficits. Subcommissural organ (SCO)-spondin is a brain-specific glycoprotein produced during embryogenesis and has a substantial impact on neuronal development. In the current study, we sought to evaluate the protective effects of the linear (NX210) and cyclized (NX210c) forms of a SCO-spondin-derived peptide on learning and memory in a mouse model of AD. Mice received an intracerebroventricular injection of Aβ_25–35 oligomers and were subsequently treated with intraperitoneal injections of vehicle, NX210 or NX210c of different doses (ranging from 0.1 to 30 mg/kg) and therapy paradigms (early or late stand-alone treatments, combination with donepezil or second-line treatment). Cognitive function was evaluated using Y-Maze, step-through latency passive avoidance (STPA) and Morris water maze (MWM) tests for up to 4 months. Early stage daily treatment with NX210 and NX210c decreased the levels of common pathological markers and features of AD, including Aβ_1–42, phosphorylated-tau, inflammation, astrogliosis and lipid peroxidation. Meanwhile, use of these drugs increased the levels of synaptophysin and postsynaptic density protein 95. Regardless of the experimental paradigm used, NX210 and NX210c prevented Aβ_25–35-induced decrease in spontaneous alternations (Y-Maze) and step-through latency into the dark compartment (STPA), and Aβ_25–35-induced increase in time needed to locate the immersed platform during the learning phase and decrease in time spent in the target quadrant during the retention phase (MWM). Interestingly, this study provides the novel evidence that the native and oxidized cyclic forms of the SCO-spondin-derived peptide reduce pathological factors associated with AD and restore learning and memory at both early and late disease stages. Overall, this study sheds light on the therapeutic potential of this innovative disease-modifying peptide to restore memory function in patients with AD.

Effects of probiotics supplementation on dementia and cognitive impairment: A systematic review and meta-analysis of preclinical and clinical studies

BACKGROUND

Dementia is a chronic syndrome characterized by cognitive and behavioral symptoms, which may include short-term memory impairment and problems related to orientation, language, attention and perception. Although cognitive impairment (CI) is increasingly considered the main geriatric condition predisposing to dementia, its early management could still promote symptomatic relief and delay disease progression. Recently, probiotics treatment has been studied as a potential new therapeutic approach to attenuate dementia-related decline and mild cognitive impairment (MCI). Therefore, we conducted a systematic review and meta-analysis to review and analyse the available evidence on the effect of probiotics on MCI and dementia.

METHODS

A systematic search and meta-analysis were performed on Cochrane Library, ProQuest, Web of Science, PubMed-Medline, The Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, ScienceDirect and Open Grey. Search terms included diagnoses of interest (dementia and MCI) and the intervention of interest (probiotic, lactobacillus and bifidobacterium). Original articles reporting the use of probiotics supplementation for the treatment of dementia and MCI were screened and studied independently by two researchers. After that, a random and fixed effects model was used at the meta-analysis stage of the results to determine its effect size.

RESULTS

A total of 16 articles (10 preclinical and 6 clinical) that met the inclusion criteria for the systematic review, and 15 articles (10 preclinical and 5 clinical) for meta-analysis were finally included. In humans, the administration of probiotics improved general cognitive function after the treatment period. Similarly, an improvement in memory and spatial/non-spatial learning was identified in the probiotic group of animals compared to the control group. On the other hand, the results showed an increase in the levels of the brain-derived neurotrophic factor, an improvement in the inflammatory profile and regulation of cellular biomarkers after probiotics administration.

CONCLUSION

Probiotics supplementation could be an adequate therapeutic strategy both in dementia and CI based on clinical and preclinical evidence. However, it is therefore important to translate preclinical data into clinical data where the evidence is more limited.

Association of changes in self-reported sleep duration with mild cognitive impairment in the elderly: a longitudinal study

As a symptomatic predementia stage with progressive cognitive decline, mild cognitive impairment (MCI) is common with aging. How changes in self-reported sleep duration affect MCI risk in the older adults remains unclear. Participants aged ≥ 65 years and enrolled at least two waves in the Chinese Longitudinal Healthy Longevity Survey were included in present longitudinal study. Changes in sleep duration were calculated as the difference between two waves and categorized into five groups: decreased >2 h, decreased 0-2h, stable, increased 0-2 h, and increased >2 h. MCI was measured by the Chinese version of the Mini-Mental State Examination. Generalized estimating equation model and restricted cubic spline function was applied to investigate the association. Among 9,005 participants (mean age, 81.19 years; 4,391 male), 2,877 developed MCI. Comparing with individuals with stable sleep duration, MCI risk [odds ratio (95% confidence intervals)] was: 1.15 (0.99-1.34) for decreased >2 h, 0.99 (0.87-1.13) for decreased 0-2h, 1.09 (0.95-1.24) for increased 0-2 h, and 1.57 (1.36-1.81) for increased >2 h, respectively. Similar patterns were observed among subgroup analyses by sex, age, and sleep quality at baseline. For participants with long sleep duration at baseline (>8h), further increased >2 h was associated with higher MCI risk [2.23 (1.55-3.21)]. Either in the whole or subgroup population, a U-shaped association was observed (P_{non-linearity}<0.05). In conclusion, changes in self-reported sleep duration were associated with MCI risk in a U-shaped pattern. Strategies that shifting sleep duration into normal range and keeping it stable are essential to prevent MCI in clinical practice.

Assessment of Racial/Ethnic Disparities in Timeliness and Comprehensiveness of Dementia Diagnosis in California

Importance

The US aging population is rapidly becoming more racially and ethnically diverse. Early diagnosis of dementia is a health care priority.

Objective

To examine the associations between race/ethnicity and timeliness of dementia diagnosis and comprehensiveness of diagnostic evaluation.

Design, Setting, and Participants

This retrospective cross-sectional study used 2013-2015 California Medicare fee-for-service data to examine the associations of race/ethnicity, individual factors, and contextual factors with the timeliness and comprehensiveness of dementia diagnosis. Data from 10 472 unique beneficiaries were analyzed. The sample was selected on the basis of the following criteria: presence of 1 or more claims; no diagnoses of dementia or mild cognitive impairment in 2013 to 2014; continuous enrollment in Medicare Parts A and B; Asian, Black, Hispanic, or White race/ethnicity; and incident diagnoses of dementia or mild cognitive impairment in January through June 2015. Data analyses were conducted from November 1, 2019, through November 10, 2020.

Main Outcomes and Measures

Timeliness of diagnosis, defined as incident diagnosis of mild cognitive impairment vs dementia, and comprehensiveness of diagnostic evaluation, defined as presence of the following services in claims within 6 months before or after the incident diagnosis date: specialist evaluation, laboratory testing, and neuroimaging studies.

Results

The sample comprised 10 472 unique Medicare beneficiaries with incident diagnoses of dementia or mild cognitive impairment (6504 women [62.1%]; mean [SD] age, 82.9 [8.0] years) and included 993 individuals who identified as Asian (9.5%), 407 as Black (3.9%), 1255 as Hispanic (12.0%), and 7817 as White (74.6%). Compared with White beneficiaries, those who identified as Asian (odds ratio, 0.46; 95% CI, 0.38-0.56), Black (odds ratio, 0.73; 95% CI, 0.56-0.94), or Hispanic (odds ratio, 0.62; 95% CI, 0.52-0.72) were less likely to receive a timely diagnosis. Asian beneficiaries (incidence rate ratio, 0.81; 95% CI, 0.74-0.87) also received fewer diagnostic evaluation elements. These associations remained significant after adjusting for age, sex, comorbidity burden, neighborhood disadvantage, and rurality.

Conclusions and Relevance

These findings highlight substantial disparities in the timeliness and comprehensiveness of dementia diagnosis. Public health interventions are needed to achieve equitable care for people living with dementia across all racial/ethnic groups.

A Primary Care Agenda for Brain Health: A Scientific Statement From the American Heart Association

A healthy brain is critical for living a longer and fuller life. The projected aging of the population, however, raises new challenges in maintaining quality of life. As we age, there is increasing compromise of neuronal activity that affects functions such as cognition, also making the brain vulnerable to disease. Once pathology-induced decline begins, few therapeutic options are available. Prevention is therefore paramount, and primary care can play a critical role. The purpose of this American Heart Association scientific statement is to provide an up-to-date summary for primary care providers in the assessment and modification of risk factors at the individual level that maintain brain health and prevent cognitive impairment. Building on the 2017 American Heart Association/American Stroke Association presidential advisory on defining brain health that included "Life's Simple 7," we describe here modifiable risk factors for cognitive decline, including depression, hypertension, physical inactivity, diabetes, obesity, hyperlipidemia, poor diet, smoking, social isolation, excessive alcohol use, sleep disorders, and hearing loss. These risk factors include behaviors, conditions, and lifestyles that can emerge before adulthood and can be routinely identified and managed by primary care clinicians.

Potential Neuroregenerative and Neuroprotective Effects of Uridine/Choline-Enriched Multinutrient Dietary Intervention for Mild Cognitive Impairment: A Narrative Review

In mild cognitive impairment (MCI) due to Alzheimer disease (AD), also known as prodromal AD, there is evidence for a pathologic shortage of uridine, choline, and docosahexaenoic acid [DHA]), which are key nutrients needed by the brain. Preclinical and clinical evidence shows the importance of nutrient bioavailability to support the development and maintenance of brain structure and function in MCI and AD. Availability of key nutrients is limited in MCI, creating a distinct nutritional need for uridine, choline, and DHA. Evidence suggests that metabolic derangements associated with ageing and disease-related pathology can affect the body's ability to generate and utilize nutrients. This is reflected in lower levels of nutrients measured in the plasma and brains of individuals with MCI and AD dementia, and progressive loss of cognitive performance. The uridine shortage cannot be corrected by normal diet, making uridine a conditionally essential nutrient in affected individuals. It is also challenging to correct the choline shortfall through diet alone, because brain uptake from the plasma significantly decreases with ageing. There is no strong evidence to support the use of single-agent supplements in the management of MCI due to AD. As uridine and choline work synergistically with DHA to increase phosphatidylcholine formation, there is a compelling rationale to combine these nutrients. A multinutrient enriched with uridine, choline, and DHA developed to support brain function has been evaluated in randomized controlled trials covering a spectrum of dementia from MCI to moderate AD. A randomized controlled trial in subjects with prodromal AD showed that multinutrient intervention slowed brain atrophy and improved some measures of cognition. Based on the available clinical evidence, nutritional intervention should be considered as a part of the approach to the management of individuals with MCI due to AD, including adherence to a healthy, balanced diet, and consideration of evidence-based multinutrient supplements.

Potentially Inappropriate Prescriptions of Antipsychotics for Patients With Dementia

Dementias are neurodegenerative and progressive diseases of the central nervous system. The objective of this study was to determine the frequency of potentially inappropriate prescriptions of antipsychotics in a group of patients diagnosed with dementia in Colombia. This was a cross-sectional study based on a population database for drug dispensing that identified prescriptions of antidementia drugs, antipsychotics, and other drugs for patients with a diagnosis of dementia. Descriptive statistics and bivariate and multivariate analyses were performed. A total of 11,372 patients with dementia were identified; 66.6% were women, and the mean age was 80.5 ± 9.6 years. Alzheimer's disease was the most frequent diagnosis (76.6%). A total of 69.0% of patients received antidementia drugs. A total of 37.1% of patients received some antipsychotic, especially atypical antipsychotics (31.0%). Increased age, being treated with memantine, simultaneously presenting with anxiety, depression, and psychotic disorders, and concomitantly receiving anticonvulsants, bronchodilators and benzodiazepines were associated with a greater probability of being prescribed antipsychotics. More than one-third of patients with dementia received antipsychotic prescriptions, which are considered potentially inappropriate because they can worsen cognitive decline and favor the occurrence of adverse events.

Radiological, Chemical, and Pharmacological Cholinergic System Parameters and Neurocognitive Disorders in Older Presurgical Adults

BACKGROUND

A pre-existing neurocognitive disorder (NCD) is a relevant factor for the outcome of surgical patients. To improve understanding of these conditions, we investigated the association between parameters of the cholinergic system and NCD.

METHOD

This investigation is part of the BioCog project (www.biocog.eu), which is a prospective multicenter observational study including patients aged 65 years and older scheduled for elective surgery. Patients with a Mini-Mental State Examination (MMSE) score ≤23 points were excluded. Neurocognitive disorder was assessed according to the fifth Diagnostic and Statistical Manual of Mental Disorders criteria. The basal forebrain cholinergic system volume (BFCSV) was assessed with magnetic resonance imaging, the peripheral cholinesterase (ChE) activities with point-of-care measurements, and anticholinergic load by analyzing the long-term medication with anticholinergic scales (Anticholinergic Drug Scale [ADS], Anticholinergic Risk Scale [ARS], Anticholinergic Cognitive Burden Scale [ACBS]). The associations of BFCSV, ChE activities, and anticholinergic scales with NCD were studied with logistic regression analysis, adjusting for confounding factors.

RESULTS

A total of 797 participants (mean age 72 years, 42% females) were included. One hundred and eleven patients (13.9%) fulfilled criteria for mild NCD and 82 patients (10.3%) for major NCD criteria. We found that AcetylChE activity was associated with major NCD (odds ratio [95% confidence interval]: [U/gHB] 1.061 [1.010, 1.115]), as well as ADS score ([points] 1.353 [1.063, 1.723]) or ARS score, respectively ([points] 1.623 [1.100, 2.397]) with major NCD. However, we found no association between BFCSV or ButyrylChE activity with mild or major NCD.

CONCLUSIONS

AcetylChE activity and anticholinergic load were associated with major NCD. Future research should focus on the association of the cholinergic system and the development of postoperative delirium and postoperative NCD.

Suggesting 7,8-dihydroxyflavone as a promising nutraceutical against CNS disorders

7,8-dihydroxyflavone (DHF), a naturally-occurring plant-based flavone, is a high-affinity tyrosine kinase receptor B (TrkB) agonist and a bioactive molecule of therapeutic interest for neuronal survival, differentiation, synaptic plasticity and neurogenesis. In the family of neurotrophic factors, this small BDNF-mimetic molecule has attracted considerable attention due to its oral bioavailability and ability to cross the blood-brain barrier. Recent evidences have shed light on the neuroprotective role of this pleiotropic flavone against several neurological disorders, including Alzheimer's disease, Parkinson's disease, cerebral ischemia, Huntington's disease, and other CNS disorders. DHF also elicits potent protective actions against toxins-induced insults to brain and neuronal cells. DHF shows promising anti-oxidant and anti-inflammatory properties in ameliorating the neurodegenerative processes affecting the CNS. This review provides an overview of the significant neuroprotective potentials of DHF and discusses how it exerts its multitudinous beneficial effects by modulating different pathways linked with the pathophysiology of CNS disorders, and thus proposes it to be a nutraceutical against a broad spectrum of neurological disorders.