Recent global trends in the prevalence and incidence of dementia, and survival with dementia

Prevalence and incidence of clinically diagnosed Alzheimer's disease dementia from 1994 to 2012 in a population study

INTRODUCTION

The trends in prevalence and incidence of Alzheimer's disease (AD) dementia remain uncertain.

METHODS

A sample of 2794 participants with a clinical diagnosis for AD dementia were included.

RESULTS

The 2010 census standardized prevalence of AD dementia was 14.5% (95% CI = 13.7-15.3), and annual incidence was 2.3% (1.7-2.9). Both prevalence and incidence showed substantial variation over time, but no secular trends. The prevalence of AD dementia did not change significantly from 14.6% (95% CI = 13.0, 16.2) in 1994-1997 to 14.7% (95% CI = 13.2, 16.2) in 2010-2012 (P = .84). The annual incidence of AD dementia was 2.8% (95% CI = 2.2, 3.2) in 1998-2000 and 2.2% (95% CI = 1.6, 2.8) in 2004-2006 (P = .20) and remained steady in 2010-2012. The prevalence and incidence among African Americans were approximately twice than those among European Americans.

CONCLUSIONS

The prevalence and incidence of AD dementia showed substantial variation between 1994 and 2012, but no secular trend.

Physical activity can improve cognition in patients with Alzheimer's disease: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND/OBJECTIVE

Alzheimer's disease (AD) is mainly characterized by decline of cognitive functions such as memory and learning, which has a high prevalence and poor drug efficacy in treatment regimes. A systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted to evaluate the effectiveness of exercise on cognitive function in patients diagnosed with AD.

METHODS

The bibliographic databases (PubMed, Cochrane Library and Embase, and Web of Science) and four Chinese databases (Wanfang data, CBM, CNKI, and VIP) were searched to identify RCTs published in any language between January 1, 1960, and January 1, 2018. Only peer-reviewed articles and RCTs were included. The collected data were analyzed by Review Manager (5.3).

RESULTS

Overall, 869 patients diagnosed with AD were included from 13 RCTs. Patients in the intervention group received pure exercise interventions and a cognitive test. Although there was heterogeneity in intervention methods and cognitive measures among studies, meta-analysis (seven studies) supports positive effects of physical activity on cognitive function of patients with AD (mean difference [MD] =2.53, the 95% CI=0.84 to 4.22, test for overall effect: Z=2.93 [P=0.003]). Eight studies demonstrated that exercise improves cognitive function for individuals with AD. However, the remaining five studies did not display a beneficial effect of exercise on cognitive function in patients with AD.

CONCLUSION

This meta-analysis and systematic review indicated that exercise intervention might improve the cognitive function of AD or slow down the decline of cognition; however, this relationship was not always true across studies. RCTs with clear intervention criteria, large samples, and long-term follow-up are needed in the future to demonstrate the benefits of exercise for cognitive function in AD patients.

Screening for Instrumental Activities of Daily Living in Sub-Saharan Africa: A Balance Between Task Shifting, Simplicity, Brevity, and Training

BACKGROUND

Task shifting has been suggested as one way to help manage the increasing burden of dementia in sub-Saharan Africa (SSA). However, brief, easy-to-use and valid screening tools are needed to support this approach. Our team has developed an 11-item questionnaire to assess instrumental activities of daily living (IADLs) in SSA, the Identification and Intervention for Dementia in Elderly Africans (IDEA)-IADL questionnaire. We aimed to externally validate the questionnaire and develop a shorter, more efficient version.

METHODS

A community-based sample of 329 older adults in 4 rural villages was screened for dementia using the validated IDEA cognitive screen and the 11-item IDEA-IADL questionnaire. A stratified sample was assessed for Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) dementia by a United Kingdom-based doctor, who was blinded to the results of screening. Area under the receiver operating characteristic (AUROC) curve analysis was used to assess validity, and factor analysis and regression modeling were used to develop a shorter version of the questionnaire.

RESULTS

A 3-item IDEA-IADL questionnaire was developed and externally validated in the study sample. The questionnaire was deemed to be valid and enhanced screening performance in 2 villages (AUROC: 0.857 and 0.895) but detracted from the accuracy of the IDEA cognitive screen in the other 2 villages (AUROC: 0.591 and 0.639). These differences appeared to be due to differences in interpretation of responses to questions by the assessors.

CONCLUSIONS

A brief IDEA-IADLs scale was developed and worked well in some villages. However, our study highlights a training need if brief screening tools to assess IADLs are to be effectively used by nonspecialists in low-resource settings.

Understanding the impact of sex and gender in Alzheimer's disease: A call to action

INTRODUCTION

Precision medicine methodologies and approaches have advanced our understanding of the clinical presentation, development, progression, and management of Alzheimer's disease (AD) dementia. However, sex and gender have not yet been adequately integrated into many of these approaches.

METHODS

The Society for Women's Health Research Interdisciplinary Network on AD, comprised of an expert panel of scientists and clinicians, reviewed ongoing and published research related to sex and gender differences in AD.

RESULTS

The current review is a result of this Network's efforts and aims to: (1) highlight the current state-of-the-science in the AD field on sex and gender differences; (2) address knowledge gaps in assessing sex and gender differences; and (3) discuss 12 priority areas that merit further research.

DISCUSSION

The exclusion of sex and gender has impeded faster advancement in the detection, treatment, and care of AD across the clinical spectrum. Greater attention to these differences will improve outcomes for both sexes.

Neuroprotective Activities of Heparin, Heparinase III, and Hyaluronic Acid on the Aβ42-Treated Forebrain Spheroids Derived from Human Stem Cells

Extracellular matrix (ECM) components of the brain play complex roles in neurodegenerative diseases. The study of microenvironment of brain tissues with Alzheimer's disease revealed colocalized expression of different ECM molecules such as heparan sulfate proteoglycans (HSPGs), chondroitin sulfate proteoglycans (CSPGs), matrix metal-loproteinases (MMPs), and hyaluronic acid. In this study, both cortical and hippocampal populations were generated from human-induced pluripotent stem cell-derived neural spheroids. The cultures were then treated with heparin (competes for Aβ affinity with HSPG), heparinase III (digests HSPGs), chondroitinase (digests CSPGs), hyaluronic acid, and an MMP-2/9 inhibitor (SB-3CT) together with amyloid β (Aβ42) oligomers. The results indicate that inhibition of HSPG binding to Aβ42 using either heparinase III or heparin reduces Aβ42 expression and increases the population of β-tubulin III+ neurons, whereas the inhibition of MMP2/9 induces more neurotoxicity. The results should enhance our understanding of the contribution of ECMs to the Aβ-related neural cell death.

A longitudinal magnetic resonance imaging study of neurodegenerative and small vessel disease, and clinical cognitive trajectories in non demented patients with transient ischemic attack: the PREVENT study

BACKGROUND

Late-life cognitive decline, caused by progressive neuronal loss leading to brain atrophy years before symptoms are detected, is expected to double in Canada over the next two decades. Cognitive impairment in late life is attributed to vascular and lifestyle related risk factors in mid-life in a substantial proportion of cases (50%), thereby providing an opportunity for effective prevention of cognitive decline if incipient disease is detected earlier. Patients presenting with transient ischemic attack (TIA) commonly display some degree of cognitive impairment and are at a 4-fold increased risk of dementia. In the Predementia Neuroimaging of Transient Ischemic Attack (PREVENT) study, we will address what disease processes (i.e., Alzheimer's vs. vascular disease) lead to neurodegeneration, brain atrophy, and cognitive decline, and whether imaging measurements of brain iron accumulation using quantitative susceptibility mapping predicts subsequent brain atrophy and cognitive decline.

METHODS

A total of 440 subjects will be recruited for this study with 220 healthy subjects and 220 TIA patients. Early Alzheimer's pathology will be determined by cerebrospinal fluid samples (including tau, a marker of neuronal injury, and amyloid β1-42) and by MR measurements of iron accumulation, a marker for Alzheimer's-related neurodegeneration. Small vessel disease will be identified by changes in white matter lesion volume. Predictors of advanced rates of cerebral and hippocampal atrophy at 1 and 3 years will include in vivo Alzheimer's disease pathology markers, and MRI measurements of brain iron accumulation and small vessel disease. Clinical and cognitive function will be assessed annually post-baseline for a period of 5-years using a clinical questionnaire and a battery of neuropsychological tests, respectively.

DISCUSSION

The PREVENT study expects to demonstrate that TIA patients have increased early progressive rates of cerebral brain atrophy after TIA, before cognitive decline can be clinically detected. By developing and optimizing high-level machine learning models based on clinical data, image-based (quantitative susceptibility mapping, regional brain, and white matter lesion volumes) features, and cerebrospinal fluid biomarkers, PREVENT will provide a timely opportunity to identify individuals at greatest risk of late-life cognitive decline early in the course of disease, supporting future therapeutic strategies for the promotion of healthy aging.

World dementia: One approach does not fit all

OBJECTIVE

To highlight the broad global diversity in the diagnosis, management, and research of dementia in different regions of the world.

METHODS

A critical review of the limited literature from the global South compared with advances that have emerged from key studies in the West and observations from the authors' experiences.

RESULTS

The last several decades have witnessed major advances in dementia research and include an understanding of epidemiologic trends in the global burden of disease, the development of biomarkers for Alzheimer disease, the identification of novel therapeutic targets, and the recognition of the role of protective life-course experiential factors. For the effective translation of these research advances into societies, a "world approach" to dementia is vital. Developing societies substantially differ from Western countries in their attitudes toward dementia, as well as their clinical manifestations and risk factor profiles, marked by lower education and socioeconomic status, a higher cardiovascular disease burden, and genetic variability. Emerging evidence emphasizes the interaction among ethnicity, genetics, epigenetics, environment, culture, and neurobiology in influencing manifestations of dementia. Therefore, the investigation of dementia in diverse settings, including a more global perspective, is crucial for a comprehensive understanding of the condition as well as the identification of novel solutions.

CONCLUSIONS

A world approach to dementia provides an opportunity to understand, manage, coordinate, and begin to prevent dementia through an integrated approach based on firm scientific evidence.

40 YEARS of IGF1: IGF1: the Jekyll and Hyde of the aging brain

The insulin-like growth factor 1 (IGF1) signaling pathway has emerged as a major regulator of the aging process, from rodents to humans. However, given the pleiotropic actions of IGF1, its role in the aging brain remains complex and controversial. While IGF1 is clearly essential for normal development of the central nervous system, conflicting evidence has emerged from preclinical and human studies regarding its relationship to cognitive function, as well as cerebrovascular and neurodegenerative disorders. This review delves into the current state of the evidence examining the role of IGF1 in the aging brain, encompassing preclinical and clinical studies. A broad examination of the data indicates that IGF1 may indeed play opposing roles in the aging brain, depending on the underlying pathology and context. Some evidence suggests that in the setting of neurodegenerative diseases that manifest with abnormal protein deposition in the brain, such as Alzheimer's disease, reducing IGF1 signaling may serve a protective role by slowing disease progression and augmenting clearance of pathologic proteins to maintain cellular homeostasis. In contrast, inducing IGF1 deficiency has also been implicated in dysregulated function of cognition and the neurovascular system, suggesting that some IGF1 signaling may be necessary for normal brain function. Furthermore, states of acute neuronal injury, which necessitate growth, repair and survival signals to persevere, typically demonstrate salutary effects of IGF1 in that context. Appreciating the dual, at times opposing 'Dr Jekyll' and 'Mr Hyde' characteristics of IGF1 in the aging brain, will bring us closer to understanding its impact and devising more targeted IGF1-related interventions.

Quality assessment of systematic reviews of vitamin D, cognition and dementia

BACKGROUND

There is conflicting evidence regarding the association of vitamin D with cognition performance and dementia.AimsWe aimed to summarise the evidence on the association of vitamin D with cognitive performance, dementia and Alzheimer disease through a qualitative assessment of available systematic reviews and meta-analyses.

METHOD

We conducted an overview of the systematic reviews of all study types with or without meta-analyses on vitamin D and either Alzheimer disease, dementia or cognitive performance up to June 2017.

RESULTS

Eleven systematic reviews were identified, nine of which were meta-analyses with substantial heterogeneity, differing statistical methods, variable methodological quality and quality of data abstraction. A Measurement Tool to Assess Systematic Reviews checklist scores ranged from 4 to 10 out of 11, with seven reviews of 'moderate' and four of 'high' methodological quality. Out of six meta-analyses on the association between low serum concentration of 25-hydroxyvitamin D and risk of dementia, five showed a positive association. Results of meta-analyses on the association between low serum concentration of 25-hydroxyvitamin D and memory function tests showed conflicting results.

CONCLUSIONS

This systematic evaluation of available systematic reviews provided a clearer understanding of the potential link between low serum vitamin D concentrations and dementia. This evaluation also showed that the quality of the available evidence is not optimal because of both the low methodological quality of the reviews and low quality of the original studies. Interpretation of these systematic reviews should therefore be made with care.Declaration of interestNone.

Time-varying effects of socio-demographic and economic factors on the use of institutional long-term care before dementia-related death: A Finnish register-based study

OBJECTIVES

The effects of socio-demographic and economic factors on institutional long-term care (LTC) among people with dementia remain unclear. Inconsistent findings may relate to time-varying effects of these factors as dementia progresses. To clarify the question, we estimated institutional LTC trajectories by age, marital status and household income in the eight years preceding dementia-related and non-dementia-related deaths.

METHODS

We assessed a population-representative sample of Finnish men and women for institutional LTC over an eight-year period before death. Deaths related to dementia and all other causes at the age of 70+ in 2001-2007 were identified from the Death Register. Dates in institutional LTC were obtained from national care registers. We calculated the average and time-varying marginal effects of age, marital status and household income on the estimated probability of institutional LTC use, employing repeated-measures logistic regression models with generalised estimating equations (GEE).

RESULTS

The effects of age, marital status and household income on institutional LTC varied across the time before death, and the patterns differed between dementia-related and non-dementia-related deaths. Among people who died of dementia, being of older age, non-married and having a lower income predicted a higher probability of institutional LTC only until three to four years before death, after which the differences diminished or disappeared. Among women in particular, the probability of institutional LTC was nearly equal across age, marital status and income groups in the last year before dementia-related death. Among those who died from non-dementia-related causes, in contrast, the differences widened until death.

CONCLUSIONS

We show that individuals with dementia require intensive professional care at the end of life, regardless of their socio-demographic or economic resources. The results imply that the potential for extending community living for people with dementia is likely to be difficult through modification of their socio-demographic and economic environments.

MicroRNA Let-7f-5p Promotes Bone Marrow Mesenchymal Stem Cells Survival by Targeting Caspase-3 in Alzheimer Disease Model

Widespread death of transplanted mesenchymal stem cells (MSCs) hampers the development of stem cell therapy for Alzheimer disease (AD). Cell pre-conditioning might help cope with this challenge. We tested whether let-7f-5p-modified MSCs could prolong the survival of MSCs after transplantation. When exposed to Aβ₂₅₋₃₅in vitro, MSCs showed significant early apoptosis with decrease in the let-7f-5p levels and increased caspase-3 expression. Upregulating microRNA let-7f-5p in MSCs alleviated Aβ₂₅₋₃₅-induced apoptosis by decreasing the caspase-3 levels. After computerized analysis and the luciferase reporter assay, we identified that caspases-3 was the target gene of let-7f-5p. In vivo, hematoxylin and eosin staining confirmed the success of MSCs transplantation into the lateral ventricles, and the let-7f-5p upregulation group showed the lowest apoptotic rate of MSCs detected by TUNEL immunohistochemistry analysis and immunofluorescence. Similarly, bioluminescent imaging showed that let-7f-5p upregulation moderately prolonged the retention of MSCs in brain. In summary, we identified the anti-apoptotic role of let-7f-5p in Aβ₂₅₋₃₅-induced cytotoxicity, as well as the protective effect of let-7f-5p on survival of grafted MSCs by targeting caspase-3 in AD models. These findings show a promising approach of microRNA-modified MSCs transplantation as a therapy for neurodegenerative diseases.

Passive Aβ Immunotherapy: Current Achievements and Future Perspectives

Passive immunotherapy has emerged as a very promising approach for the treatment of Alzheimer’s disease and other neurodegenerative disorders, which are characterized by the misfolding and deposition of amyloid peptides. On the basis of the amyloid hypothesis, the majority of antibodies in clinical development are directed against amyloid β (Aβ), the primary amyloid component in extracellular plaques. This review focuses on the current status of Aβ antibodies in clinical development, including their characteristics and challenges that came up in clinical trials with these new biological entities (NBEs). Emphasis is placed on the current view of common side effects observed with passive immunotherapy, so-called amyloid-related imaging abnormalities (ARIAs), and potential ways to overcome this issue. Among these new ideas, a special focus is placed on molecules that are directed against post-translationally modified variants of the Aβ peptide, an emerging approach for development of new antibody molecules.

Leg length, skull circumference, and the incidence of dementia in Latin America and China: A 10/66 population-based cohort study

Background

Adult leg length is influenced by nutrition in the first few years of life. Adult head circumference is an indicator of brain growth. Cross-sectional studies indicate inverse associations with dementia risk, but there have been few prospective studies.

Methods

Population-based cohort studies in urban sites in Cuba, Dominican Republic Puerto Rico and Venezuela, and rural and urban sites in Peru, Mexico and China. Sociodemographic and risk factor questionnaires were administered to all participants, and anthropometric measures taken, with ascertainment of incident dementia, and mortality, three to five years later.

Results

Of the original at risk cohort of 13,587 persons aged 65 years and over, 2,443 (18.0%) were lost to follow-up; 10,540 persons with skull circumference assessments were followed up for 40,466 person years, and 10,400 with leg length assessments were followed up for 39,954 person years. There were 1,009 cases of incident dementia, and 1,605 dementia free deaths. The fixed effect pooled meta-analysed adjusted subhazard ratio (ASHR) for leg length (highest vs. lowest quarter) was 0.80 (95% CI, 0.66–0.97) and for skull circumference was 1.02 (95% CI, 0.84–1.25), with no heterogeneity of effect between sites (I² = 0%). Leg length measurements tended to be shorter at follow-up, particularly for those with baseline cognitive impairment and dementia. However, leg length change was not associated with dementia incidence (ASHR, per cm 1.006, 95% CI 0.992–1.020), and the effect of leg length was little altered after adjusting for baseline frailty (ASHR 0.82, 95% CI 0.67–0.99). A priori hypotheses regarding effect modification by gender or educational level were not supported. However, the effect of skull circumference was modified by gender (M vs F ASHR 0.86, 95% CI 0.75–0.98), but in the opposite direction to that hypothesized with a greater protective effect of larger skull dimensions in men.

Conclusions

Consistent findings across settings provide quite strong support for an association between adult leg length and dementia incidence in late-life. Leg length is a relatively stable marker of early life nutritional programming, which may confer brain reserve and protect against neurodegeneration in later life through mitigation of cardiometabolic risk. Further clarification of these associations could inform predictive models for future dementia incidence in the context of secular trends in adult height, and invigorate global efforts to improve childhood nutrition, growth and development.

Use of statins and the risk of dementia and mild cognitive impairment: A systematic review and meta-analysis

We conducted a systematic review and meta-analysis to investigate whether the use of statins could be associated with the risk of all-caused dementia, Alzheimer’s disease (AD), vascular dementia (VaD), and mild cognitive impairment (MCI). Major electronic databases were searched until December 27^th, 2017 for studies investigating use of statins and incident cognitive decline in adults. Random-effects meta-analyses calculating relative risks (RRs) were conducted to synthesize effect sizes of individual studies. Twenty-five studies met eligibility criteria. Use of statins was significantly associated with a reduced risk of all-caused dementia (k = 16 studies, adjusted RR (aRR) = 0.849, 95% CI = 0.787–0.916, p = 0.000), AD (k = 14, aRR = 0.719, 95% CI = 0.576–0.899, p = 0.004), and MCI (k = 6, aRR = 0.737, 95% CI = 0.556–0.976, p = 0.033), but no meaningful effects on incident VaD (k = 3, aRR = 1.012, 95% CI = 0.620–1.652, p = 0.961). Subgroup analysis suggested that hydrophilic statins were associated with reduced risk of all-caused dementia (aRR = 0.877; CI = 0.818–0.940; p = 0.000) and possibly lower AD risk (aRR = 0.619; CI = 0.383–1.000; p = 0.050). Lipophilic statins were associated with reduced risk of AD (aRR = 0.639; CI = 0.449–0.908; p = 0.013) but not all-caused dementia (aRR = 0.738; CI = 0.475–1.146; p = 0.176). In conclusion, our meta-analysis suggests that the use of statins may reduce the risk of all-type dementia, AD, and MCI, but not of incident VaD.

Secular Trends in the Incidence of Dementia in a Multi-Ethnic Community

BACKGROUND

Determination of secular trends in cognitive aging is important for prioritization of resources, services, and research in aging populations. Prior studies have identified declining dementia incidence associated with changes in cardiovascular risk factors and increased educational attainment. However, few studies have examined these factors in multi-ethnic cohorts.

OBJECTIVE

To identify secular trends in the incidence rate of dementia in an elderly population.

METHODS

Participants in this study were drawn from the Washington Heights-Inwood Columbia Aging Project, a multi-ethnic cohort study of northern Manhattan residents aged 65 years and older. Cox proportional hazards models were used to examine differences in the incidence of dementia in cohorts recruited in 1992 and 1999, with age at dementia or age at last follow-up visit as the "time-to-event" variable.

RESULTS

Overall, there was a 41% reduction in the hazard ratio for dementia among participants in the 1999 cohort compared with those in the 1992 cohort, adjusting for age, sex, race, and baseline memory complaints (HR = 0.59). The reduction in incidence was greatest among non-Hispanic Whites and African-Americans and lowest among Hispanic participants (HRs = 0.60, 0.52 and 0.64, respectively), and was associated with increases in level of educational attainment, especially among African-Americans. Reduction in incidence of dementia was also greater among persons 75 years or older than among younger participants (HR = 0.52 versus HR = 0.69).

CONCLUSIONS

Our results support previous findings that secular trends in dementia incidence are changing, including in aging minority populations.

Comparisons between traditional medicines and pharmacotherapies for Alzheimer disease: A systematic review and meta-analysis of cognitive outcomes

OBJECTIVES

To evaluate the clinical evidence for traditional medicines (TMs) used in East Asia on measures of cognition in Alzheimer disease, determine the effect sizes at different time points for the TMs and pharmacotherapies, and assess the tolerability of the TMs.

METHODS

We searched 12 databases in English, Chinese, and Japanese for eligible randomised controlled trials that compared orally administered TMs with pharmacotherapy and reported cognitive outcomes. Meta-analyses were conducted for Alzheimer's Disease Assessment Scale-cognitive subscale and/or Mini-Mental State Examination (MMSE). Mean differences and 95% confidence intervals were calculated to evaluate treatment effects.

RESULTS

Thirty randomised controlled trials met inclusion criteria. Twenty-nine compared TMs with donepezil. Single studies provided comparisons with galantamine, rivastigmine, or memantine. There were no significant differences between the TM and donepezil groups at 12 or 24 weeks for Alzheimer's Disease Assessment Scale-cognitive subscale or MMSE. Improvements over baseline were significant for MMSE at 12 and 24 weeks within the TM and donepezil groups and remained significant at 1 year. Effect sizes were reduced in the 3 double-blind studies. At 24 weeks, donepezil 10 mg/d generally produced greater improvements in MMSE than 5 mg/d. Tolerability reporting was incomplete and inconsistent between studies.

CONCLUSIONS

The results suggested that the clinical benefits of the TMs were not less than donepezil at comparable time points, with both groups showing improvements. However, lack of blinding in most studies and other design and measurement issues are likely to have resulted in overestimation of effect sizes in both groups. Further well-designed studies are needed.

Synthesis, pharmacology and molecular docking on multifunctional tacrine-ferulic acid hybrids as cholinesterase inhibitors against Alzheimer's disease

The cholinergic hypothesis has long been a “polar star” in drug discovery for Alzheimer’s disease (AD), resulting in many small molecules and biological drug candidates. Most of the drugs marketed for AD are cholinergic. Herein, we report our efforts in the discovery of cholinesterases inhibitors (ChEIs) as multi-target-directed ligands. A series of tacrine-ferulic acid hybrids have been designed and synthesised. All these compounds showed potent acetyl-(AChE) and butyryl cholinesterase(BuChE) inhibition. Among them, the optimal compound 10g, was the most potent inhibitor against AChE (electrophorus electricus (eeAChE) half maximal inhibitory concentration (IC₅₀) = 37.02 nM), it was also a strong inhibitor against BuChE (equine serum (eqBuChE) IC₅₀ = 101.40 nM). Besides, it inhibited amyloid β-protein self-aggregation by 65.49% at 25 μM. In subsequent in vivo scopolamine-induced AD models, compound 10g obviously ameliorated the cognition impairment and showed preliminary safety in hepatotoxicity evaluation. These data suggest compound 10g as a promising multifunctional agent in the drug discovery process against AD.

The effectiveness of ICT-based neurocognitive and psychosocial rehabilitation programmes in people with mild dementia and mild cognitive impairment using GRADIOR and ehcoBUTLER: study protocol for a randomised controlled trial

Background

Cognitive rehabilitation is a highly individualised, non-pharmacological intervention for people with mild cognitive impairment (MCI) and dementia, which in recent years has also been developed for various IT platforms.

Methods

In this study, we aim to evaluate the effectiveness of the cognitive rehabilitation software GRADIOR in a multi-centre, single-blinded randomised controlled trial with people with MCI and mild dementia. A total of 400 people with MCI and mild dementia will be randomly allocated to one of four groups. This trial will compare the cognitive rehabilitation treatment using the GRADIOR programme with a psychosocial stimulation intervention (PSS) using the ehcoBUTLER platform, with a combined treatment consisting of GRADIOR and ehcoBUTLER, and with a group receiving treatment as usual during a period of 1 year.

Discussion

The outcomes of this clinical trial will be to determine any relevant changes in cognition, mood, quality of life, activities of daily living and quality of patient-carer relationship after 4 months and 1 year of intervention in a cross-sectional group comparison. Participants will be followed-up for 1 year to investigate potential long-term effects of the conducted treatments.

Trial registration

Current Controlled Trials ISRCTN, ID: 15742788. Registered on 12 June 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2371-z) contains supplementary material, which is available to authorized users.

Proactive approaches to identifying dementia and dementia risk; a qualitative study of public attitudes and preferences

OBJECTIVES

The aim of this study was to critically explore the views of the public about the acceptability and feasibility of proactive approaches to earlier dementia diagnosis and also identification of people at high risk of dementia.

DESIGN

Qualitative study using task group methodology and thematic data analysis.

SETTING

Task groups were held either at the university (n=5) or at a carers' centre (n=1).

PARTICIPANTS

A convenience sample of 31 of 54 participants identified by local non-statutory agencies took part in a task group. All were aged between 40 years and 80 years, 21 were women and 10men participated.

RESULTS

Despite the use of task group methodology, participants expressed limited understandings of dementia and confusion between proactive approaches. Nevertheless, they highlighted a range of potential benefits and limitations of proactive approaches and the ethical issues raised. There was a preference to embed risk assessment within routine health checks, which focused on achieving a healthier lifestyle, rather than specifically on dementia. Participants emphasised the need to ensure informed consent prior to use of proactive approaches and to provide appropriate support. They also suggested alternative approaches that could potentially facilitate the early detection of dementia or reduce risk at a population level.

CONCLUSIONS

As international policy on dementia shifts towards a prevention agenda there is growing interest in identifying those at risk of developing dementia. This study provides useful insights into the acceptability of the use of such proactive approaches among the public. The introduction of proactive approaches to dementia identification raises complex practical and ethical issues, particularly in the context of low public understanding of dementia. The importance of better quality information about dementia (and the likelihood of developing dementia) and provision of psychological support for those undergoing risk assessment were highlighted.

Neuropathology correlates of cognitive assessments

BACKGROUND

Alzheimer's disease and other dementias are the fourth largest contributors to neurological disability and the second largest contributor to deaths from neurological disease. Described in the 1980s as 'the silent epidemic' these disorders principally, though not exclusively, affect persons 80 years or older, and in developed countries, this 'old old' population continues to grow. Definitive diagnosis of the underlying cause of the neurodegenerative disease relies on neuropathological evaluation.` AIMS: Herein, we review the sampling methods, analysis and interpretation of both pathological and immunocytochemical techniques in the diagnostic assessment of neurodegenerative disease.

FINDINGS

Neurodegenerative disorders are characterised by accumulation of pathologically altered protein in the human brain, and in some cases, in the peripheral tissues. Whilst it is suggested that a comprehensive review of the patient's clinical history, cognition and behaviour, together with a full clinical examination and radiological analysis, should lead to a high degree of confidence in the clinical diagnosis, the view persists that underlying pathology can only be predicted on clinical grounds especially in Alzheimer's disease, vascular brain injury and diffuse Lewy body disease with only limited accuracy.

CONCLUSIONS

Neuropathological assessment of well characterised clinical cases provides accurate data on the prevalence of neurodegenerative diseases. This will aid future biomarker, neuroimaging studies and clinical trials focussed on population based cohorts.

Population Neuroscience: Dementia Epidemiology Serving Precision Medicine and Population Health

Over recent decades, epidemiology has made significant contributions to our understanding of dementia, translating scientific discoveries into population health. Here, we propose reframing dementia epidemiology as "population neuroscience," blending techniques and models from contemporary neuroscience with those of epidemiology and biostatistics. On the basis of emerging evidence and newer paradigms and methods, population neuroscience will minimize the bias typical of traditional clinical research, identify the relatively homogenous subgroups that comprise the general population, and investigate broader and denser phenotypes of dementia and cognitive impairment. Long-term follow-up of sufficiently large study cohorts will allow the identification of cohort effects and critical windows of exposure. Molecular epidemiology and omics will allow us to unravel the key distinctions within and among subgroups and better understand individuals' risk profiles. Interventional epidemiology will allow us to identify the different subgroups that respond to different treatment/prevention strategies. These strategies will inform precision medicine. In addition, insights into interactions between disease biology, personal and environmental factors, and social determinants of health will allow us to measure and track disease in communities and improve population health. By placing neuroscience within a real-world context, population neuroscience can fulfill its potential to serve both precision medicine and population health.

Predictors of institutionalization in people with dementia: a survey linked with administrative data

BACKGROUND

For people with dementia, moving into a nursing home is usually considered at some point in time. Currently available information on predictors of institutionalization is often based on small sample sizes, not taking competing risks into account, and with inconclusive results for sex.

AIMS

We aimed to carry out an analysis stratified by sex and using a competing risk approach.

METHODS

We carried out an analysis of a survey linked with administrative data including 652 people with dementia, aged 60 years and older. The follow-up was up to 4.5 years. We used the cumulative incidence function for examining time until institutionalization and survival time and the sub-distribution hazard model for estimating hazard ratios.

RESULTS

The participants were on average 81 years old, about 51% were female. At the end of the follow-up, 282 people had been institutionalized and 273 had died. The regression models show that the risk of institutionalization is higher in women than in men and when cared for by a care service in comparison to an informal caregiver. Inhibiting factors are Care Level (II, III) and positive evaluation of caregiving by caregivers. Stratified analysis by sex revealed that the risk of institutionalization in men is influenced by their relationship to their caregiver, in women by duration of care at baseline.

DISCUSSION

Sex seems to play a role in predicting institutionalization.

CONCLUSION

Future research should focus on stratified analysis by sex. Knowing the predictors of institutionalization for men and women could influence long-term care management remarkably.

The prevalence of dementia in a Portuguese community sample: a 10/66 Dementia Research Group study

Background

Dementia imposes a high burden of disease worldwide. Recent epidemiological studies in European community samples are scarce. In Portugal, community prevalence data is very limited. The 10/66 Dementia Research Group (DRG) population-based research programmes are focused in low and middle income countries, where the assessments proved to be culture and education fair. We applied the 10/66 DRG prevalence survey methodology in Portugal, where levels of illiteracy in older populations are still high.

Methods

A cross-sectional comprehensive one-phase survey was conducted of all residents aged 65 and over of two geographically defined catchment areas in Southern Portugal (one urban and one rural site). Nursing home residents were not included in the present study. Standardized 10/66 DRG assessments include a cognitive module, an informant interview and the Geriatric Mental State-AGECAT, providing data on dementia diagnosis and subtypes, mental disorders including depression, physical health, anthropometry, demographics, disability/functioning, health service utilization, care arrangements and caregiver strain.

Results

We interviewed 1405 old age participants (mean age 74.9, SD = 6.7 years; 55.5% women) after 313 (18.2%) refusals to participate.

The prevalence rate for dementia in community-dwellers was 9.23% (95% CI 7.80–10.90) using the 10/66 DRG algorithm and 3.65% (95% CI 2.97–4.97) using DSM-IV criteria. Pure Alzheimer’s disease was the most prevalent dementia subtype (41.9%). The prevalence of dementia was strongly age-dependent for both criteria, but there was no association with sex.

Conclusions

Dementia prevalence was higher than previously reported in Portugal. The discrepancy between prevalence according to the 10/66 DRG algorithm and the DSM-IV criteria is consistent with that observed in less developed countries; this suggests potential underestimation using the latter approach, although relative validity of these two approaches remains to be confirmed in the European context. We improved the evidence base to raise awareness and empower advocacy about dementia in Portugal, so that the complex needs of frail older people may be met in better ways.

Impact of diabetes mellitus and chronic liver disease on the incidence of dementia and all-cause mortality among patients with dementia

This study investigated the effects of the presence of type 2 diabetes mellitus (T2D) and/or chronic liver disease (CLD) on the incidence and prognosis of dementia during a 10-year period in Korea using a nationwide population-based dataset from the Korea National Health Insurance Service.To assess the impact of T2D and CLD on the incidence of dementia, we included subjects aged ≥60 years without dementia, T2D, and CLD from 2003 to 2005. We created another cohort for evaluating the all-cause mortality in subjects with dementia between 2003 and 2005. The participants were categorized into 4 groups: control (neither CLD nor T2D), CLD-only, T2D-only, and T2D-and-CLD groups, and they were followed up until 2013.The incidence of dementia was higher in the T2D-only group than in the control and CLD-only groups (2.78 vs. 2.04 and 2.00 per 1000 person-years). After adjustment for age, gender, and comorbid conditions, both T2D and CLD increased the risk of any type of dementia; however, the impact of CLD alone was much lower [hazard ratio (HR) 1.07, 95% confidence interval (CI): 1.06-1.08] than that of T2D alone (HR 1.27, 95% CI: 1.27-1.28). The risk of dementia did not significantly change in patients with the co-occurrence of T2D and CLD compared to those with T2D alone. The all-cause mortality rate was the lowest in the control group (2.59 per 1000 person-years) and the highest in the T2D-and-CLD group (3.77 per 1000 person-years). Presence of T2D or CLD alone was associated with higher mortality (HR 1.46 and HR 1.21, respectively) compared with in the absence of both the diseases. Furthermore, the presence of both the diseases further significantly increased the mortality rate compared to the presence of each disease alone (HR 1.67, 95% CI: 1.65-1.69).In conclusion, this study found that the incidence of dementia was much higher in patients with T2D. CLD was associated with a modest increase in risk of dementia; however, there was no additive effect with T2D. In the population with dementia, however, the presence of CLD was associated with high mortality in patients with or without T2D.

Differential contribution of microglia and monocytes in neurodegenerative diseases

Neuroinflammation is a hallmark of neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). Microglia, the innate immune cells of the CNS, are the first to react to pathological insults. However, multiple studies have also demonstrated an involvement of peripheral monocytes in several neurodegenerative diseases. Due to the different origins of these two cell types, it is important to distinguish their role and function in the development and progression of these diseases. In this review, we will summarize and discuss the current knowledge of the differential contributions of microglia and monocytes in the common neurodegenerative diseases AD, PD, and ALS, as well as multiple sclerosis, which is now regarded as a combination of inflammatory processes and neurodegeneration. Until recently, it has been challenging to differentiate microglia from monocytes, as there were no specific markers. Therefore, the recent identification of specific molecular signatures of both cell types will help to advance our understanding of their differential contribution in neurodegenerative diseases.

PARP-1 and p53 Regulate the Increased Susceptibility to Oxidative Death of Lymphocytes from MCI and AD Patients

Mild cognitive impairment (MCI) is a clinically detectable initial stage of cognitive deterioration with a high conversion rate to dementia. There is increasing evidence that some of the cerebral alterations present in Alzheimer type dementia can be found in peripheral tissues. We have previously shown that lymphocytes from Alzheimer’s disease (AD) patients have increased susceptibility to hydrogen peroxide (H₂O₂)-induced death that depends on dementia severity. We here investigated whether lymphocytes from MCI patients show increased vulnerability to death, and explored the involvement of Poly [ADP-ribose] polymerase (PARP-1) and p53 in the regulation of this process. Lymphocytes from 16 MCI and 10 AD patients, and 15 healthy controls (HCs) were submitted to increasing concentrations of H₂O₂ for 20 h. Cell death was determined by flow cytometry, in the presence or absence of PARP-1 inhibitors (3-aminobenzamide (3-ABA) or Nicotinamide (NAM)), or the p53 inhibitor (nutlin-3) or stabilizer (pifithrin-α). PARP-1 and p53 mRNA levels were determined by quantitative PCR (qPCR). Lymphocytes from MCI patients showed increased susceptibility to death, attaining intermediate values between AD and controls. PARP inhibitors -3-ABA and NAM- markedly protected from H₂O₂-induced death, making the difference between MCI and controls disappear, but not the difference between AD and controls. PARP-1 mRNA expression was increased in MCI lymphocytes. Modulation of p53 with Nutlin-3 or pifithrin-α did not modify the H₂O₂-induced death of lymphocytes from MCI or AD patients, but augmented the death in control lymphocytes attaining levels similar to MCI and AD. Accordingly, p53 mRNA expression was increased in AD and MCI lymphocytes compared to controls. In all, these results show that increased oxidative death is present in lymphocytes at the MCI stage. PARP-1 has a preponderant role, with complete death protection achieved with PARP inhibition in MCI lymphocytes, but not in AD, suggesting that PARP-1 might have a protective role. In addition, deregulations of the p53 pathway seem to contribute to the H₂O₂-induced death in MCI and AD lymphocytes, which show increased p53 expression. The results showing a prominent protective role of PARP inhibitors opens the door to study the use of these agents to prevent oxidative death in MCI patients.

Global, regional, and national burden of neurological disorders during 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

BACKGROUND

Comparable data on the global and country-specific burden of neurological disorders and their trends are crucial for health-care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study provides such information but does not routinely aggregate results that are of interest to clinicians specialising in neurological conditions. In this systematic analysis, we quantified the global disease burden due to neurological disorders in 2015 and its relationship with country development level.

METHODS

We estimated global and country-specific prevalence, mortality, disability-adjusted life-years (DALYs), years of life lost (YLLs), and years lived with disability (YLDs) for various neurological disorders that in the GBD classification have been previously spread across multiple disease groupings. The more inclusive grouping of neurological disorders included stroke, meningitis, encephalitis, tetanus, Alzheimer's disease and other dementias, Parkinson's disease, epilepsy, multiple sclerosis, motor neuron disease, migraine, tension-type headache, medication overuse headache, brain and nervous system cancers, and a residual category of other neurological disorders. We also analysed results based on the Socio-demographic Index (SDI), a compound measure of income per capita, education, and fertility, to identify patterns associated with development and how countries fare against expected outcomes relative to their level of development.

FINDINGS

Neurological disorders ranked as the leading cause group of DALYs in 2015 (250·7 [95% uncertainty interval (UI) 229·1 to 274·7] million, comprising 10·2% of global DALYs) and the second-leading cause group of deaths (9·4 [9·1 to 9·7] million], comprising 16·8% of global deaths). The most prevalent neurological disorders were tension-type headache (1505·9 [UI 1337·3 to 1681·6 million cases]), migraine (958·8 [872·1 to 1055·6] million), medication overuse headache (58·5 [50·8 to 67·4 million]), and Alzheimer's disease and other dementias (46·0 [40·2 to 52·7 million]). Between 1990 and 2015, the number of deaths from neurological disorders increased by 36·7%, and the number of DALYs by 7·4%. These increases occurred despite decreases in age-standardised rates of death and DALYs of 26·1% and 29·7%, respectively; stroke and communicable neurological disorders were responsible for most of these decreases. Communicable neurological disorders were the largest cause of DALYs in countries with low SDI. Stroke rates were highest at middle levels of SDI and lowest at the highest SDI. Most of the changes in DALY rates of neurological disorders with development were driven by changes in YLLs.

INTERPRETATION

Neurological disorders are an important cause of disability and death worldwide. Globally, the burden of neurological disorders has increased substantially over the past 25 years because of expanding population numbers and ageing, despite substantial decreases in mortality rates from stroke and communicable neurological disorders. The number of patients who will need care by clinicians with expertise in neurological conditions will continue to grow in coming decades. Policy makers and health-care providers should be aware of these trends to provide adequate services.

FUNDING

Bill & Melinda Gates Foundation.

Dementia risk and prevention by targeting modifiable vascular risk factors

The incidence of dementia is expected to double in the next 20 years and will contribute to heavy social and economic burden. Dementia is caused by neuronal loss that leads to brain atrophy years before symptoms manifest. Currently, no cure exists and extensive efforts are being made to mitigate cognitive impairment in late life in order to reduce the burden on patients, caregivers, and society. The most common type of dementia, Alzheimer's disease (AD), and vascular dementia (VaD) often co-exists in the brain and shares common, modifiable risk factors, which are targeted in numerous secondary prevention trials. There is a growing need for non-pharmacological interventions and infrastructural support from governments to encourage psychosocial and behavioral interventions. Secondary prevention trials need to be redesigned based on the risk profile of individual subjects, which require the use of validated and standardized clinical, biological, and neuroimaging biomarkers. Multi-domain approaches have been proposed in high-risk populations that target optimal treatment; clinical trials need to recruit individuals at the highest risk of dementia before symptoms develop, thereby identifying an enriched disease group to test preventative and disease modifying strategies. The underlying aim should be to reduce microscopic brain tissue loss by modifying vascular and lifestyle risk factors over a relatively short period of time, thus optimizing the opportunity for preventing dementia in the future. Collaboration between international research groups is of key importance to the optimal use and allocation of existing resources, and the development of new techniques in preventing dementia. This article is part of the Special Issue "Vascular Dementia".

A modified formulation of Huanglian-Jie-Du-Tang reduces memory impairments and β-amyloid plaques in a triple transgenic mouse model of Alzheimer's disease

Alzheimer’s disease (AD) is a degenerative disorder typified by progressive deterioration of memory and the appearance of β-amyloid peptide (Aβ)-rich senile plaques. Recently we have identified a novel function of a patented formulation of modified Huanglian-Jie-Tu-Tang (HLJDT-M), a Chinese herbal medicine, in treating AD in in vitro studies (US patent No. 9,375,457). HLJDT-M is a formulation composed of Rhizoma Coptitis, Cortex Phellodendri and Fructus Gardeniae without Radix Scutellariae. Here, we assessed the efficacy of HLJDT-M on a triple transgenic mouse model of AD (3XTg-AD). Oral administration of HLJDT-M ameliorated the cognitive dysfunction of 3XTg-AD mice and lessened the plaque burden. In addition, biochemical assays revealed a significant decrease in levels of detergent-soluble and acid-soluble Aβ via decreasing the levels of full length amyloid-β precursor protein (FL-APP) and C-terminal fragments of APP (CTFs) in brain lysates of HLJDT-M-treated mice. HLJDT-M treatment also significantly reduced the levels of FL-APP and CTFs in N2a/SweAPP cells. In contrast, treatment using the classical formula HLJDT did not reduce the memory impairment of 3XTg-AD mice and, rather, increased the Aβ/Fl-APP/CTFs in both animal and cell culture studies. Altogether, our study indicates that HLJDT-M is a promising herbal formulation to prevent and/or cure AD.

Effectiveness of Light Therapy in Cognitively Impaired Persons: A Metaanalysis of Randomized Controlled Trials

OBJECTIVES

To explore the effects of light therapy on behavioral disturbances (BDs), sleep quality, and depression.

DESIGN

Meta-analysis of randomized controlled trials.

SETTING

PubMed, Cochrane Library, Medline, EMBASE, Web of Science, and clinicaltrials.gov of selected randomized controlled trials and previous systematic reviews were searched.

PARTICIPANTS

Cognitively impaired persons.

MEASUREMENTS

Information was extracted on study characteristics, quality assessment, and outcomes. Outcome measures included BDs, sleep quality, and depression.

RESULTS

Nine randomized controlled trials were examined. The results showed that light therapy has a moderate effect on BD (g = -0.61) and depression (g = -0.58) and a small effect on total sleep time at night (g = 0.25). Subgroup analysis indicated that a light intensity of 2,500 lux or greater has a greater effect on depression than an intensity of less than 2,500 lux (P = .03), and the low risk of bias in blinding was superior to the RCTs deemed to be of high or unclear risk of bias in blinding in terms of BD (P = .02).

CONCLUSION

Light therapy can relieve BD, improve sleep quality, and alleviate symptoms of depression for cognitively impaired persons.

Dementia in Latin America: Epidemiological Evidence and Implications for Public Policy

Population aging is among the most important global transformations. Today, 12% of the world population is of age 60 and over and by the middle of this century this segment will represent 21.5%. The increase in population of those aged 80 and over, also referred to as the "oldest old" or the "very elderly", will be even more pronounced, going from 1.7% of the population to 4.5% within the same period. Compared to European and North American countries, Latin America (LA) is experiencing this unprecedented demographic change at a significantly faster rate. Due to demographic and health transitions, the number of people with dementia will rise from 7.8 million in 2013 to over 27 million by 2050. Nowadays, the global prevalence of dementia in LA has reached 7.1%, with Alzheimer's Disease (AD) being the most frequent type. This level is similar to those found in developed countries; however, the dementia rate is twice as high as that of the 65-69 years age group in developed countries. In addition, the prevalence and incidence of dementia is higher among illiterate people. Mortality rates due to dementia have risen considerably. The burden and costs of the disease are high and must be covered by patients' families. The prevention of dementia and the development of long-term care policies and plans for people with dementia in LA, which take into account regional differences and similarities, should be urgent priorities.

The GABA-Working Memory Relationship in Alzheimer's Disease

Alzheimer’s disease (AD) is a highly debilitating neurodegenerative disease with no cure to date. Emerging evidence indicates aberrations of the primary inhibitory neurotransmitter GABA in the frontal, parietal and temporal cortices, and hippocampal regions of the AD brains. GABA levels have been reported to predict working memory (WM) load capacity in the healthy young population. Since working memory is impaired in AD, it opens an active area of research to investigate the influence of GABA on WM performance in AD. Advancements in neuroimaging techniques and signal processing tools can aid in neurochemical profiling of GABA in AD as well as facilitate in probing the role of GABA in AD-specific impairments of working memory.

Temporal trend in dementia incidence since 2002 and projections for prevalence in England and Wales to 2040: modelling study

Objective To forecast dementia prevalence with a dynamic modelling approach that integrates calendar trends in dementia incidence with those for mortality and cardiovascular disease.Design Modelling study.Setting General adult population of England and Wales.Participants The English Longitudinal Study of Ageing (ELSA) is a representative panel study with six waves of data across 2002-13. Men and women aged 50 or more years, selected randomly, and their cohabiting partners were recruited to the first wave of ELSA (2002-03). 11392 adults participated (response rate 67%). To maintain representativeness, refreshment participants were recruited to the study at subsequent waves. The total analytical sample constituted 17 906 people. Constant objective criteria based on cognitive and functional impairment were used to ascertain dementia cases at each wave.Main outcome measures To estimate calendar trends in dementia incidence, correcting for bias due to loss to follow-up of study participants, a joint model of longitudinal and time-to-event data was fitted to ELSA data. To forecast future dementia prevalence, the probabilistic Markov model IMPACT-BAM (IMPACT-Better Ageing Model) was developed. IMPACT-BAM models transitions of the population aged 35 or more years through states of cardiovascular disease, cognitive and functional impairment, and dementia, to death. It enables prediction of dementia prevalence while accounting for the growing pool of susceptible people as a result of increased life expectancy and the competing effects due to changes in mortality, and incidence of cardiovascular disease.Results In ELSA, dementia incidence was estimated at 14.3 per 1000 person years in men and 17.0/1000 person years in women aged 50 or more in 2010. Dementia incidence declined at a relative rate of 2.7% (95% confidence interval 2.4% to 2.9%) for each year during 2002-13. Using IMPACT-BAM, we estimated there were approximately 767 000 (95% uncertainty interval 735 000 to 797 000) people with dementia in England and Wales in 2016. Despite the decrease in incidence and age specific prevalence, the number of people with dementia is projected to increase to 872 000, 1 092 000, and 1 205 000 in 2020, 2030, and 2040, respectively. A sensitivity analysis without the incidence decline gave a much larger projected growth, of more than 1.9 million people with dementia in 2040.Conclusions Age specific dementia incidence is declining. The number of people with dementia in England and Wales is likely to increase by 57% from 2016 to 2040. This increase is mainly driven by improved life expectancy.

Risk of hospitalization with neurodegenerative disease after moderate-to-severe traumatic brain injury in the working-age population: A retrospective cohort study using the Finnish national health registries

BACKGROUND

Previous epidemiological studies suggest that working-aged persons with a history of moderate-to-severe traumatic brain injury (TBI) may have an increased risk for developing neurodegenerative disease (NDD) while persons with a history of mild TBI do not. In this comprehensive nationwide study in Finland, we assessed the risk of NDD and history of moderate-to-severe TBI in the working-age population.

METHODS AND FINDINGS

We performed a population-based follow-up study using the Finnish Care Register for Health Care to identify all persons between the ages of 18 and 65 years hospitalized during 1987-2014 due to TBI who did not have a baseline NDD diagnosis. We compared the risk of hospitalization with NDD between persons hospitalized due to moderate-to-severe TBI (intracranial lesions) and persons hospitalized due to mild TBI (no intracranial lesions). Follow-up NDD diagnoses were recorded from 1 year following the TBI to the end of 2014. NDD diagnoses included dementia, Parkinson disease, and amyotrophic lateral sclerosis. We used a Cox proportional hazards model, adjusting for age, sex, education, and socioeconomic group, to assess the association between TBI and NDD. In total, 19,936 and 20,703 persons with a history of moderate-to-severe TBI and mild TBI, respectively, were included. The overall time at risk was 453,079 person-years (median 10 years per person). In total, 3.5% (N = 696) persons in the moderate-to-severe TBI group developed NDD compared to 1.6% (N = 326) in the mild TBI group. After adjusting for covariates, moderate-to-severe TBI was associated with an increased risk for NDD, with a hazard ratio (HR) of 1.8 (95% CI 1.6-2.1) compared to mild TBI. Of the NDD subtypes, only moderate-to-severe TBI was associated with an increased risk for dementia (HR 1.9, 95% CI 1.6-2.2). Yet, this large-scale epidemiological study does not prove that there is a causal relationship between moderate-to-severe TBI and NDD. Further, the Care Register for Health Care includes only hospitalized persons; thus, patients diagnosed with NDD in the outpatient setting may have been missed. Additional limitations include the potential for miscoding and unmeasured confounds.

CONCLUSIONS

In working-aged persons, a history of moderate-to-severe TBI is associated with an increased risk for future dementia but not for Parkinson disease or amyotrophic lateral sclerosis.

Strategies for dementia prevention: latest evidence and implications

Dementia is a common and debilitating syndrome with enormous impact on individuals and societies. Preventing disease onset or progression would translate to public health and societal benefits. In this review, we discuss the latest evidence on interventions that may show promise for the prevention of cognitive decline. We appraise existing evidence primarily drawn from randomized controlled trials, systematic reviews, and meta-analyses, but also highlight observational studies in humans and relevant work in model organisms. Overall, there is currently limited evidence to support a cause-effect relationship between any preventive strategy and the development or progression of dementia. However, studies to date suggest that a multifactorial intervention comprising regular exercise and healthy diet, along with the amelioration of vascular risk factors, psychosocial stress, and major depressive episodes may be most promising for the prevention of cognitive decline. We discuss the challenges, future directions, and implications of this line of research.

Association between human herpesvirus infections and dementia or mild cognitive impairment: a systematic review protocol

INTRODUCTION

Persisting neurotropic viruses are proposed to increase the risk of dementia, but evidence of association from robust, adequately powered population studies is lacking. This is essential to inform clinical trials of targeted preventive interventions.

METHODS AND ANALYSIS

We will carry out a comprehensive systematic review of published and grey literature of the association between infection with, reactivation of, vaccination against or treatment of any of the eight human herpesviruses and dementia or mild cognitive impairment. We will search the Cochrane Library, Embase, Global Health, Medline, PsycINFO, Scopus, Web of Science, clinical trials registers, the New York Academy of Medicine Grey Literature Report, Electronic Theses Online Service through the British Library and the ISI Conference Proceedings Citation Index for randomised controlled trials, cohort, caseâ€"control, case crossover or self-controlled case series studies reported in any language up to January 2017. Titles, abstracts and full-text screening will be conducted by two researchers independently. Data will be extracted systematically from eligible studies using a piloted template. We will assess risk of bias of individual studies in line with the Cochrane Collaboration tool. We will conduct a narrative synthesis, grouping studies by exposure and outcome definitions, and will describe any differences by population subgroups and dementia subtypes. We will consider performing meta-analyses if there are adequate numbers of sufficiently homogeneous studies. The overall quality of cumulative evidence will be assessed using selected Grading of Recommendations, Assessment, Development and Evaluations criteria.

ETHICS AND DISSEMINATION

As this is a review of existing studies, no ethical approval is required. Results will be disseminated through a peer-reviewed publication and at national and international conferences. We anticipate the review will clarify the current extent and quality of evidence for a link between herpesviruses and dementia, identify gaps and inform the direction of future research.

PROSPERO REGISTRATION NUMBER

CRD42017054684.

Cognitive stimulation therapy as a sustainable intervention for dementia in sub-Saharan Africa: feasibility and clinical efficacy using a stepped-wedge design

BACKGROUND

Cognitive stimulation therapy (CST) is a psychosocial group-based intervention for dementia shown to improve cognition and quality of life with a similar efficacy to cholinesterase inhibitors. Since CST can be delivered by non-specialist healthcare workers, it has potential for use in low-resource environments, such as sub-Saharan Africa (SSA). We aimed to assess the feasibility and clinical effectiveness of CST in rural Tanzania using a stepped-wedge design.

METHODS

Participants and their carers were recruited through a community dementia screening program. Inclusion criteria were DSM-IV diagnosis of dementia of mild/moderate severity following detailed assessment. No participant had a previous diagnosis of dementia and none were taking a cholinesterase inhibitor. Primary outcomes related to the feasibility of conducting CST in this setting. Key clinical outcomes were changes in quality of life and cognition. The assessing team was blind to treatment group membership.

RESULTS

Thirty four participants with mild/moderate dementia were allocated to four CST groups. Attendance rates were high (85%) and we were able to complete all 14 sessions for each group within the seven week timeframe. Substantial improvements in cognition, anxiety, and behavioral symptoms were noted following CST, with smaller improvements in quality of life measures. The number needed to treat was two for a four-point cognitive (adapted Alzheimer's Disease Assessment Scale-Cognitive) improvement.

CONCLUSIONS

This intervention has the potential to be low-cost, sustainable, and adaptable to other settings across SSA, particularly if it can be delivered by non-specialist health workers.

The changing prevalence and incidence of dementia over time - current evidence

Dementia is an increasing focus for policymakers, civil organizations and multidisciplinary researchers. The most recent descriptive epidemiological research into dementia is enabling investigation into how the prevalence and incidence are changing over time. To establish clear trends, such comparisons need to be founded on population-based studies that use similar diagnostic and research methods consistently over time. This narrative Review synthesizes the findings from 14 studies that investigated trends in dementia prevalence (nine studies) and incidence (five studies) from Sweden, Spain, the UK, the Netherlands, France, the USA, Japan and Nigeria. Besides the Japanese study, these studies indicate stable or declining prevalence and incidence of dementia, and some provide evidence of sex-specific changes. No single risk or protective factor has been identified that fully explains the observed trends, but major societal changes and improvements in living conditions, education and healthcare might have favourably influenced physical, mental and cognitive health throughout an individual's life course, and could be responsible for a reduced risk of dementia in later life. Analytical epidemiological approaches combined with translational neuroscientific research could provide a unique opportunity to explore the neuropathology that underlies changing occurrence of dementia in the general population.

Primary motor cortex alterations in Alzheimer disease: A study in the 3xTg-AD model

INTRODUCTION

In humans and animal models, Alzheimer disease (AD) is characterised by accumulation of amyloid-β peptide (Aβ) and hyperphosphorylated tau protein, neuronal degeneration, and astrocytic gliosis, especially in vulnerable brain regions (hippocampus and cortex). These alterations are associated with cognitive impairment (loss of memory) and non-cognitive impairment (motor impairment). The purpose of this study was to identify cell changes (neurons and glial cells) and aggregation of Aβ and hyperphosphorylated tau protein in the primary motor cortex (M1) in 3xTg-AD mouse models at an intermediate stage of AD.

METHODS

We used female 3xTg-AD mice aged 11 months and compared them to non-transgenic mice of the same age. In both groups, we assessed motor performance (open field test) and neuronal damage in M1 using specific markers: BAM10 (extracellular Aβ aggregates), tau 499 (hyperphosphorylated tau protein), GFAP (astrocytes), and Klüver-Barrera staining (neurons).

RESULTS

Female 3xTg-AD mice in intermediate stages of the disease displayed motor and cellular alterations associated with Aβ and hyperphosphorylated tau protein deposition in M1.

CONCLUSIONS

Patients with AD display signs and symptoms of functional impairment from early stages. According to our results, M1 cell damage in intermediate-stage AD affects motor function, which is linked to progression of the disease.

Update on Alzheimer's and the Dementias: Introduction

Though the numbers of dementia cases are rising worldwide, there is evidence that incidence rates are decreasing. We now know that the neuropathological changes of Alzheimer's disease (AD) precede overt clinical signs by 15 to 20 years and we have biochemical and imaging markers that enable us to identify them. The genetic complexity of AD suggests it is not a single entity but rather represents a group of related diseases. The amyloid cascade hypothesis has led to the development of putative disease-modifying interventions but these have not yet been demonstrated to be substantively effective and additional approaches are warranted.

Optimising care for patients with cognitive impairment and dementia following hip fracture

The global shift in demographics towards aging populations is leading to a commensurate increase in age-related disease and frailty. It is essential to optimise health services to meet current needs and prepare for anticipated future demands. This paper explores issues impacting on people living with cognitive impairment and/or dementia who experience a hip fracture and are cared for in acute settings. This is important given the high mortality and morbidity associated with this population. Given the current insufficiency of clear evidence on optimum rehabilitation of this patient group, this paper explored three key themes namely: recognition of cognitive impairment, response by way of training and education of staff to optimise care for this patient group and review of the importance of outcomes measures. Whilst there is currently insufficient evidence to draw conclusions about the optimal ways of caring for patients living with dementia following hip fracture, this paper concludes that future research should improve understanding of healthcare staff education to improve the outcomes for this important group of patients.

Dementia incidence trend over 1992-2014 in the Netherlands: Analysis of primary care data

BACKGROUND

Recent reports have suggested declining age-specific incidence rates of dementia in high-income countries over time. Improved education and cardiovascular health in early age have been suggested to be bringing about this effect. The aim of this study was to estimate the age-specific dementia incidence trend in primary care records from a large population in the Netherlands.

METHODS AND FINDINGS

A dynamic cohort representative of the Dutch population was composed using primary care records from general practice registration networks (GPRNs) across the country. Data regarding dementia incidence were obtained using general-practitioner-recorded diagnosis of dementia within the electronic health records. Age-specific dementia incidence rates were calculated for all persons aged 60 y and over; negative binomial regression analysis was used to estimate the time trend. Nine out of eleven GPRNs provided data on more than 800,000 older people for the years 1992 to 2014, corresponding to over 4 million person-years and 23,186 incident dementia cases. The annual growth in dementia incidence rate was estimated to be 2.1% (95% CI 0.5% to 3.8%), and incidence rates were 1.08 (95% CI 1.04 to 1.13) times higher for women compared to men. Despite their relatively low numbers of person-years, the highest age groups contributed most to the increasing trend. There was no significant overall change in incidence rates since the start of a national dementia program in 2003 (-0.025; 95% CI -0.062 to 0.011). Increased awareness of dementia by patients and doctors in more recent years may have influenced dementia diagnosis by general practitioners in electronic health records, and needs to be taken into account when interpreting the data.

CONCLUSIONS

Within the clinical records of a large, representative sample of the Dutch population, we found no evidence for a declining incidence trend of dementia in the Netherlands. This could indicate true stability in incidence rates, or a balance between increased detection and a true reduction. Irrespective of the exact rates and mechanisms underlying these findings, they illustrate that the burden of work for physicians and nurses in general practice associated with newly diagnosed dementia has not been subject to substantial change in the past two decades. Hence, with the ageing of Western societies, we still need to anticipate a dramatic absolute increase in dementia occurrence over the years to come.

What's the "Take Home" from Research on Dementia Trends?

Eric Larson and Kenneth Langa discuss whether the risk of dementia is increasing or decreasing over time.