Epidemiology of early-onset dementia: a review of the literature

Researching the causal relationship between immune cells and frontotemporal Dementia: A Mendelian Randomization analysis

BACKGROUND

Frontotemporal dementia (FTD) is a prevalent dementia syndrome with poorly understood immunological underpinnings. Despite the widespread adoption of high-density genotyping technologies like SNPs and CNVs, and advances in genome-wide association studies (GWAS), the immunological mechanisms underlying FTD remain elusive. This study aims to elucidate the causal relationships between immune cell traits and FTD using Mendelian randomization (MR).

METHODS

We utilized summary data for FTD (cases = 129, controls = 392,463) from the FinnGen dataset and summary statistics for 731 immune cell traits from the GWAS catalog. These traits included morphological parameters (MP = 32), median fluorescence intensity (MFI = 389), absolute cell counts (AC = 118), and relative cell counts (RC = 192). Our approach encompassed forward MR (immune cell traits as exposure) and reverse MR (FTD as exposure), accompanied by rigorous sensitivity analyses to assess the robustness and heterogeneity of the findings.

RESULTS

FTD did not have a statistically significant impact on immune phenotypes. Notably, we identified 13 immune phenotypes as protective against FTD, including various T cell and B cell markers. Conversely, 8 phenotypes were associated with increased FTD risk, involving markers on myeloid cells and subsets of T and B cells; CONCLUSION: This MR study identifies specific immune phenotypes associated with FTD, highlighting potential pathways for future clinical research and therapeutic intervention.

Assessing social cognition and risk-taking behaviour in patients with young-onset dementia: Study protocol for the YOD-RiSoCo observational prospective cohort study

BACKGROUND

Certain subtypes of young onset dementia (YOD), such as the behavioural variant of FTD or the behavioural variant of AD (bvYOD), present with changes in social behaviour instead of memory impairments. These symptoms are often under-recognized, delaying the diagnosis and contributing to psychosocial problems. Impairments in social cognition (SC), an important affected domain in bvYOD, underlie these social behavioural changes. Especially emotional blunting and a lack of empathy in patients with bvYOD might be related to problematic social behaviour, such as risk-taking behaviour, which may potentially harm others. However, despite the importance of SC impairments in the diagnosis of YOD and the impact of SC impairments on social behaviour, there is a lack of valid and well normed measures for certain aspects of SC, such as emotion experience and empathy.

METHODS

The YOD-RiSoCo study is an observational prospective cohort study, consisting of two separate, but related, studies. Study 1 includes 64 patients with bvYOD and 64 healthy controls to assess the sensitivity and validity of newly developed SC instruments for measuring emotion experience and empathy, by comparing their average group performance. Furthermore, validity of the new instruments will be assessed by analysing the associations of performances on these new tests with those on more traditional SC and other neurocognitive tests. Study 2 focuses on assessing to which extent SC measures relate to risk-taking behaviour. This study includes 20 patients with bvYOD and 20 healthy controls from Study 1, in addition to 20 patients with non-bvYOD (e.g. Alzheimer's dementia or vascular dementia) and 20 patients with serious brain injury affecting frontal networks. A specific question is whether the relationship between SC and risk-taking behaviour is generic (for all groups with SC impairments), or specific (not in dementia without SC impairments).

DISCUSSION

Results of the YOD-RiSoCo study will yield new, sensitive neuropsychological tests for aspect of social cognition, which may contribute to a more timely diagnosis of YOD, allowing earlier provision of appropriate counselling and care for patients and their close others. Furthermore, the study will contribute to a better identification of those social behavioural symptoms that negatively affect functioning and social relations.

TRIAL REGISTRATION

The trial is registered at www.clinicaltrials.gov with identifier NCT06286293.

Longitudinal trends in dementia prevalence among individuals with type 2 diabetes in Taiwan (2009-2022)

OBJECTIVE

This study examined the population-based epidemiological prevalence of early- and late-onset dementia in individuals with type 2 diabetes mellitus (T2DM) compared with the general population in Taiwan from 2009 to 2022.

METHODS

A 14-year nationwide population-based epidemiology study from 2009 to 2022 in Taiwan using the Taiwan National Health Insurance Research Database was conducted to examine the crude and age-standardized dementia prevalence in individuals aged <65 and ≥65. Multivariable logistic regression was used to assess factors associated with dementia prevalence in the T2DM population.

RESULTS

Among individuals aged ≥65 with T2DM, age-standardized dementia prevalence increased from 5.83 per 100 in 2009 to 7.11 per 100 in 2022, while the crude prevalence ratio compared to the general population ranged from 1.19 to 1.08. In the 40-64 age group, standardized dementia prevalence ranged from 0.58 to 0.43 per 100, with crude ratios ranging from 1.76 to 1.41. Our study found a higher risk of dementia prevalence among individuals aged 65 years and older, particularly among those with T2DM. Although the overall prevalence of dementia in the 40-64 age group was lower compared to older adults, individuals in this younger group with T2DM exhibited a significantly higher risk of developing dementia. Given these findings, public policy should prioritize early preventive strategies for individuals with T2DM to monitor and mitigate dementia progression in patients with T2DM.

Public attitudes toward dementia risk prediction: A mixed-methods study

INTRODUCTION

Numerous dementia risk prediction models have been developed, but uptake in clinical practice is poor.

METHODS

We determined public attitude toward dementia risk prediction through the means of a focus group (n = 9) and subsequent online survey (n = 687). Thematic content analysis was used for focus group data and descriptive statistics for survey responses.

RESULTS

Focus group participants expressed reluctance in knowing dementia risk due to fear, emotional burden, and belief that prevention was impossible. Conversely, practical benefits and maximizing present quality of life motivated others to know dementia risk. Of survey respondents, 66.1% would want to know their 10-year risk at present, increasing to 82.3% if preventive medication were available. People perceived their 10-year risk as rather high, yet lower still than their own personal threshold for considering preventive action.

DISCUSSION

Development and implementation of dementia risk prediction tools require attention for personal actionability and emotional impact of risk communication.

HIGHLIGHTS

Among citizens with a particular interest in dementia, a large group is keen to learn their personal dementia risk, particularly when effective preventive measures are available. In focus group participants, hesitancy to learn about dementia risk was common, driven by fear, emotional burden, and doubts about the effectiveness of preventive interventions. The majority of survey participants (72%) believed a healthy lifestyle could reduce dementia risk. People perceived their 10-year risk as rather high, yet lower still than their own personal threshold for considering preventive action.

Hallmarks of aging in age-related macular degeneration and age-related neurological disorders: novel insights into common mechanisms and clinical relevance

Age-related macular degeneration (AMD) and age-related neurological diseases (ANDs), such as Alzheimer's and Parkinson's Diseases, are increasingly prevalent conditions that significantly contribute to global morbidity, disability, and mortality. The retina, as an accessible part of the central nervous system (CNS), provides a unique window to study brain aging and neurodegeneration. By examining the associations between AMD and ANDs, this review aims to highlight novel insights into fundamental mechanisms of aging and their role in neurodegenerative disease progression. This review integrates knowledge from the emerging field of aging research, which identifies common denominators of biological aging, specifically loss of proteostasis, impaired macroautophagy, mitochondrial dysfunction, and inflammation. Finally, we emphasize the clinical relevance of these pathways and the potential for cross-disease therapies that target common aging hallmarks. Identifying these shared pathways could open avenues to develop therapeutic strategies targeting mechanisms common to multiple degenerative diseases, potentially attenuating disease progression and promoting the healthspan.

Monoaminergic Alterations at the Subregional Cervical and Thoracic Spinal Cord Level of Patients Within the FTD-ALS Continuum and Early-Onset AD: Low Thoracic Dopaminergic Activity in ALS

Early-onset neurodegeneration leads to cognitive and behavioral symptoms in frontotemporal dementia (FTD) and motor disturbances in amyotrophic lateral sclerosis (ALS). Despite distinct clinical profiles, more than half of FTD patients experience ALS-related symptoms and vice versa. Spinal cord monoamine neurotransmitter alterations were reported in ALS, but not yet in FTD. Therefore, we compared monoaminergic turnover across the FTD-ALS continuum. Reversed-phase, ultra-high-performance liquid chromatography with electrochemical detection was used to measure levels of the monoamines (nor)adrenaline ((N)A), dopamine (DA) and serotonin (5-hydroxytryptamine, 5-HT) and their metabolites 3-methoxy-4-hydroxyphenylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in five cervical and thoracic spinal cord regions in 10 FTD, 14 ALS, 6 mixed FTD-ALS, 14 early-onset Alzheimer's disease (EOAD), and 7 control (CONTR) individuals. At the cervical level, NA levels were lower in FTD-ALS versus CONTR, whereas the HVA/5-HIAA ratio was higher in ALS versus EOAD in the lateral funiculus. In the dorsal horn-intermediate gray matter, DA levels were decreased in FTD-ALS compared to FTD. At the thoracic level, DOPAC was lower in ALS than in FTD-ALS patients in the ventral and lateral funiculus, ventral horn, and dorsal horn-intermediate gray matter, as was the DOPAC/DA ratio in the lateral funiculus and dorsal horn-intermediate gray matter. Contrarily, HVA/DA turnover was lower in FTD-ALS than in FTD in the dorsal and ventral funiculus. We observed lower NA levels in FTD-ALS than in FTD in the ventral funiculus, and lower MHPG/NA turnover in the dorsal horn-intermediate gray matter. A levels were lower in ALS versus FTD. This study indicates differences in monoaminergic turnover across the FTD-ALS continuum, at the cervical and thoracic levels, with primarily a decrease in dopaminergic activity in ALS. Characterizing disease-specific neurochemical profiles for FTD, ALS, or FTD-ALS could contribute to the identification of novel interesting pharmacological targets.

Global burden of young-onset dementia, from 1990 to 2021: an age-period-cohort analysis from the global burden of disease study 2021

This study aims to assess the burden of young-onset dementia worldwide, regionally, and nationally during 1990-2021. Prevalence, incidence, mortality, and disability adjusted life years (DALYs) rates were used to estimate burden of the young-onset dementia. The average annual percentage was utilized to evaluate the trends during 1990-2021. Decomposition analysis was performed to explore driving factors behind changes. Age-period-cohort modeling was used to estimate local drift, age, period and cohort effects. Global age standardized prevalence and incidence of dementia among people under 65 years increased from 93.39 and 16.24 per 100,000 persons in 1990 to 96.09 and 17.16 per 100,000 persons in 2021; mortality increased from 0.89 per 100,000 population to 0.91 per 100,000 population; and age standardized DALYs increased from 45.60 per 100,000 persons to 46.78 per 100,000 persons. Countries with a high, high-middle, and middle SDI experienced an upward trend of prevalence and incidence, and the mortality and DALYs of young-onset dementia in countries with a low-middle and low sociodemographic index was a higher level. Smoking, high body-mass index and high fasting plasma glucose levels were main risk factors. Population growth was the largest factor for the increasing young-onset dementia in all regions. Globally, prevalence, incidence, and DALYs rate of young-onset dementia increased with age, period effects showing a decreasing risk and then an increasing risk. Cohort effects of prevalence and DALYs began to decline after the 1950s. Young-onset dementia presents a growing global health challenge in the age, period and cohort across SDI regions, countries.

Noninvasive Brain Stimulation in Primary Progressive Aphasia with and Without Concomitant Speech and Language Therapy: Systematic Review and Meta-analysis

Primary progressive aphasias (PPA) represent a group of neurodegenerative conditions affecting verbal communication abilities for which no effective medication is currently available. Noninvasive brain stimulation (NiBS) has been mainly explored as adjunctive therapy to conventional speech and language therapy (SLT) with promising results. The present meta-analysis of randomized-controlled trials (RCTs) aims to evaluate the efficacy of NiBS in PPA patients on a range of linguistic tasks (naming, phonemic fluency, semantic fluency). A literature search was carried out using EMBASE and PUBMED, searching for multi-session RCTs administering NiBS on PPA patients as stand-alone or with SLT. The results were not significant overall, indicating a null difference between the active and the sham condition on language functions; pooled effects tended to be higher in parallel than in crossover studies and for follow-ups than post-treatment. In the naming analyses, the combined effects for the studies that coupled NiBS with SLT were slightly higher than the overall effect at each time point, although not significant. These results need to be considered with caution given the low number of included studies and small sample sizes, but offer relevant indications for future research in terms of optimal treatment protocols and personalization of therapies.

Linking structural and functional changes during healthy aging and semantic dementia using multilayer brain network analysis

Healthy aging is characterized by frontal and diffuse brain changes, while certain age-related pathologies such as semantic dementia will be associated with more focal brain lesions, particularly in the temporo-parietal regions. These changes in structural integrity could influence functional brain networks. Here we use multilayer brain network analysis on structural (DWI) and functional (fMRI) data in younger and older healthy individuals and patients with semantic dementia. Relative to younger adults, results revealed lower levels of similarity of connectivity patterns between brain structure and function, and an increased network clustering in frontal regions in healthy older individuals. These changes were either associated with a preservation (similarity) and a decrease (clustering) in cognitive performance. Patients with semantic dementia showed an increase in the similarity of structural and functional connectivity patterns, as well as an increase in clustering in temporo-parietal regions. These changes were respectively associated with a preservation and a decrease in cognitive performance. These results provide a better characterization of distinct profiles of age- and pathology-brain network changes and their association with the preservation or the decline of cognitive functions.

Insights into young-onset dementia hospitalizations: An 8-year nationwide study using administrative data

OBJECTIVE

To characterize all Portuguese public hospitalizations of patients aged < 65 years with a primary or secondary diagnosis of dementia, based on ICD-9-CM coding.

METHODS

A retrospective observational study was conducted using a nationwide database encompassing all hospitalizations occurred in Portuguese mainland public hospitals with discharge from 2008 to 2015. Hospitalizations of patients aged 35-64 years with primary or secondary diagnoses of dementia were selected based on ICD-9-CM codes 290.1X-290.4X, 291.2, 292.82, 294.1X, 294.2X, 331.0, 331.1X, 331.82, 333.4 and 046.1, excluding diagnostic codes 317-319, 330.X, 343, 758.0-758.3 and 759.3. Information on age, sex, primary diagnosis, comorbidities (secondary diagnosis), type of admission, length of stay (LoS), in-hospital mortality, suicide attempts, discharge destination, readmissions and dementia etiology was collected.

RESULTS

From 7971 hospitalizations, for 5682 inpatients, the median age was 57.3 years (SD±6.5) and 61.8% were of male patients. Vascular dementia was the most prevalent etiology, followed by Alzheimer's disease. Most admissions were urgent and had a primary diagnosis of 'Delirium, dementia and other cognitive disorders', followed by pneumonia and alcohol-related disorders. Dementia, cerebrovascular disease and diabetes were the most common comorbidities. Overall, 55.4% of admissions were first-time admissions during the study period and the median LoS was 10.0 days (Q1;Q3: 5.0;20.0). Suicide attempts were recorded in 0.6% of the episodes. The in-hospital mortality rate was 9.2% and most patients were discharged home (80.2%).

CONCLUSIONS

This study describes the complexity and strain of young-onset dementia hospitalizations providing a detailed overview and recommendations for further research and tailored interventions.

Earnings losses in young-onset dementia: Population-based study with admin data

INTRODUCTION

Young-onset dementia is often diagnosed late, leaving gaps in understanding its impact on employment, income, and social security.

METHODS

Analyzing health insurance claims and medical records, we studied 16,010 young-onset dementia cases and 129,616 matched controls. Using a non-parametric event study, we assessed earnings, earnings plus benefits, employment losses, and benefit use, considering demographic and socio-economic factors.

RESULTS

Earnings fell by 58.7% in the years prior to dementia identification, totaling €144,013 in losses, and earnings plus benefits decreased by 20.7% (€68,533). We observed a 35.5 percentage point decrease in employment, a 23.9 percentage point increase in disability insurance, and a 2.7 percentage point rise in welfare benefit use. Primary education and lack of a partner correlated with higher earning losses and lower disability insurance uptake.

DISCUSSION

Early diagnosis and robust social support systems are vital to alleviate the financial and professional challenges faced by individuals with dementia under age 65.

HIGHLIGHTS

Working-age persons experience job loss at least 21 years before dementia identification. Job loss is linked to 59% (€16,643) earnings drop 16 years before dementia identification. Losses in earning were not fully compensated by social insurance. A generous social insurance system eases the financial impact of young-onset dementia. Attention is needed in the work environment and on disability benefit decisions.

Exercise intensity of virtual reality exergaming modulates the responses to executive function and affective response in sedentary young adults: A randomized, controlled crossover feasibility study

Virtual reality (VR) exergaming is a novel strategy to encourage physical activity and boost emotional well-being. However, its effects on executive function (EF) are not fully understood. This study assessed the immediate and retention effects of immersive VR exergaming, at varying exercise intensities, on EF and affect among sedentary college students. Thirty participants (mean age = 22.2 ± 2.5 years; 18 females) underwent 15-minute sessions of moderate-intensity (MI), high-intensity (HI), and active-control intensity (AC) VR exergaming in a counterbalanced order. EF was evaluated using the Flanker, Task-switching, and N-back tasks before, immediately after, and 30 min post-intervention. Emotional valence and arousal were measured by the Feeling Scale and Felt Arousal Scale, respectively. The inverse efficiency score (IES) results indicated that inhibitory control was higher following both MI and HI exergaming compared to AC (p < 0.05), with improvements sustained for 30 minutes HI VR exergaming showed the greatest improvement (p = 0.048). Both HI and MI also exhibited higher working memory capacity than AC (p < 0.05), with HI performing better (p = 0.039). No significant differences in task-switching performance were observed among the groups (p > 0.05). Emotional valence and arousal were significantly elevated immediately after and sustained for 30 minutes following MI and HI exergaming (p < 0.05). This study demonstrates the cognitive and affective benefits of MI and HI VR exergaming in young adults, with HI VR exergaming showing longer-lasting improvements. These findings suggest that immersive VR exergaming can enhance both physical and cognitive health, potentially improving academic performance and daily functionality in collegiate populations.

Development of the Telephone-based Daily Instrumental Activities of Living (T-DIAL) to assess financial management remotely in older adults

The current study evaluated the reliability and validity of a novel, performance-based banking task in 60 younger (18-34 years) and 60 older (50-85 years) adults. All participants completed the Telephone-based Daily Instrumental Activities of Living (T-DIAL) using interactive voice response technology to complete a series of mock actions with a financial institution via telephone. The T-DIAL showed strong inter-rater reliability and internal consistency. T-DIAL accuracy was significantly and independently related to better self-reported instrumental activities of daily living and executive functions at a large effect size. Findings from this study provided preliminary supportive evidence for the reliability and validity of the T-DIAL, which had robust associations with manifest everyday functioning and higher-order cognitive ability. Future work is needed on the psychometrics (e.g. test-retest reliability, normative standards), and construct validity (e.g. diagnostic accuracy) of the T-DIAL in neurocognitive disorders and under-served communities for whom remote evaluations might be particularly relevant.

Measurement of blood-brain barrier water exchange rate using diffusion-prepared and multi-echo arterial spin labelling: Comparison of quantitative values and age dependence

Water exchange rate (Kw) across the blood-brain barrier (BBB) is an important physiological parameter that may provide new insight into ageing and neurodegenerative disease. Recently, two non-invasive arterial spin labelling (ASL) MRI methods have been developed to measure Kw, but results from the different methods have not been directly compared. Furthermore, the association of Kw with age for each method has not been investigated in a single cohort. Thirty participants (70% female, 63.8 ± 10.4 years) were scanned at 3 T with Diffusion-Prepared ASL (DP-ASL) and Multi-Echo ASL (ME-ASL) using previously implemented acquisition and analysis protocols. Grey matter Kw, cerebral blood flow (CBF) and arterial transit time (ATT) were extracted. CBF values were consistent; approximately 50 ml/min/100 g for both methods, and a strong positive correlation in CBF from both methods across participants (r = 0.82, p < 0.001). ATT was significantly different between methods (on average 147.7 ms lower when measured with DP-ASL compared to ME-ASL) but was positively correlated across participants (r = 0.39, p < 0.05). Significantly different Kw values of 106.6 ± 19.7 min-1 and 306.8 ± 71.7 min-1 were measured using DP-ASL and ME-ASL, respectively, and DP-ASL Kw and ME-ASL Kw were negatively correlated across participants (r = -0.46, p < 0.01). Kw measured using ME-ASL had a significant linear relationship with age (p < 0.05). In conclusion, DP-ASL and ME-ASL provided estimates of Kw with significantly different quantitative values and inconsistent dependence with age. We propose future standardisation of modelling and fitting methods for DP-ASL and ME-ASL, to evaluate the effect on Kw quantification. Also, sensitivity and bias analyses should be performed for both approaches, to assess the effect of varying acquisition and fitting parameters. Lastly, comparison with independent measures of BBB water transport, and with physiological and clinical biomarkers known to be associated with changes in BBB permeability, are essential to validate the ASL methods, and to demonstrate their clinical utility.

MRI-Based Multi-Class Relevance Vector Machine Classification of Neurodegenerative Diseases

Machine learning algorithms are a promising automated candidate that can help mitigate the growing need for dementia experts. Despite the substantial development in MRI-based machine learning analyses, case misclassification is a universal finding, yet the reasons behind misclassification are poorly understood. We implemented a multi-class classification approach that uses relevance vector machine and logistic classification to classify research participants based on their whole-brain T1-weighted MRI scans. A total of 468 participants from seven diagnostic classes were included: 144 healthy controls, 84 Alzheimer's disease, 108 behavioral variant frontotemporal dementia (bvFTD), 30 semantic variant primary progressive aphasia (svPPA), 30 non-fluent variant primary progressive aphasia (nfvPPA), 30 corticobasal syndrome (CBS), and 42 progressive supranuclear palsy syndrome (PSPS). We compared the algorithm's diagnostic accuracy against the clinical, pathological, genetic, and quantitative imaging data. The exact neurodegenerative syndrome was predicted in 71% of the cases, the neurodegenerative disease spectrum was predicted in 80% of the cases, and the algorithm distinguished controls from any dementia in 85% of the cases. The algorithm showed high performance in diagnosing healthy controls, moderate performance in diagnosing AD, bvFTD, and svPPA, and low performance in diagnosing CBS, nfvPPA, and PSPS. Based on the quantitative imaging data, most of the misclassified neurodegenerative cases had minimal atrophy and brain volumes comparable to healthy controls. In AD, early-onset AD cases with minimal brain atrophy represented most of the misclassified cases. In bvFTD, FTD genetic mutation carriers (predominantly C9orf72 repeat expansion), FTD phenocopy, patients meeting only possible bvFTD criteria represented most misclassified cases. Case misclassification in machine learning studies in neurodegenerative diseases results from neurodegenerative disease heterogeneity and the limitations of structural MRI's ability to capture the whole gamut of biological changes. Larger and more inclusive datasets that are representative of population biologic heterogeneity are needed to train better machine learning techniques, and a margin of error is expected and should be acceptable, like the uncertainty of a clinical diagnosis by a dementia expert.

Associations between concussion and more severe TBIs, mild cognitive impairment, and early-onset dementia among military retirees over 40 years

Background and objectives

As the population of U.S. service members (SMs) who have sustained concussions and more severe traumatic brain injuries (TBIs) during military service ages, understanding the long-term outcomes associated with such injuries will provide critical information that may promote long-term assessment, support, and rehabilitation following military service. The objective of this research was to examine whether concussion and more severe TBIs are associated with greater risk of precursors to dementia (i.e., mild cognitive impairment, memory loss), early-onset dementia, and any dementia.

Methods

This study used a retrospective cohort design wherein archival medical and career records from 1980 to 2020 identified U.S. military personnel who retired from military service and their corresponding Tricare-reimbursable medical encounters in inpatient and/or outpatient settings in military treatment facilities and/or purchased care settings both before and after retirement. All military personnel who served on active duty between 1980 and 2020 and were at least 45 years of age by 2020 were eligible for inclusion (N = 6,092,432). Those who were discharged from military service with a retirement designation, and were thus eligible for Tricare for Life, were included in the analytic sample (N = 1,211,972). Diagnoses of concussion and more severe TBI during active duty service recorded in inpatient settings between 1980 and 2020 and in outpatient settings from 2001 to 2020 were identified. Focal outcomes of interest included memory loss, mild cognitive impairment, Alzheimer's, Lewy Body dementia, frontotemporal dementia, and vascular dementia. Dementia diagnoses before age 65 were labeled early-onset.

Results

Those with (vs. without) concussion diagnoses during military service were significantly more likely to be diagnosed with memory loss and mild cognitive impairment and any of the dementias examined. However, they were not at greater risk of being diagnosed with early-onset dementia.

Discussion

Military SMs diagnosed with concussion may be at elevated risk for long-term neurodegenerative outcomes including memory loss, mild cognitive impairment, and dementia. As the population of SMs who sustained TBI during the Global War on Terror continue to age, the prevalence of dementia will increase and may bring a unique burden to the VHA.

Incidence and Prevalence of Early-Onset Dementia in Finland

OBJECTIVES

Current epidemiologic data of early-onset dementia (EOD), characterized by the onset of the disease before the age of 65, are notably scarce.

METHODS

We evaluated the incidence (from January 2010 to December 2021) and prevalence (on December 31, 2021) of EOD and its subtypes in 2 defined areas in Finland. All visits at the dementia outpatient clinics were manually retrospectively reviewed and reassessed (N = 12,490).

RESULTS

In the population aged ≤65 years, crude incidence of EOD was 12.3/100,000 persons at risk/year based on 794 new cases from January 1, 2010, to December 31, 2021. Incidence rates for EOD were 20.5 and 33.7 per 100,000 person years in the age group of 30-64 and 45-64 years, respectively. The prevalence of EOD was 110.4 in the age group of 30-64 years and 190.3 in the age group 45-64. Alzheimer disease (AD) (48.2%) and behavioral variant frontotemporal dementia (12.7%) were the most frequent subtypes. The incidence of AD increased during the follow-up, whereas incidence of other forms of EOD remained stable.

DISCUSSION

We found higher incidence rates of EOD than previously reported. Unlike other forms of EOD, the incidence of early-onset AD seems to be increasing.

An anti-sortilin affibody-peptide fusion inhibits sortilin-mediated progranulin degradation

Heterozygous loss-of-function mutations in the GRN gene are a common cause of frontotemporal dementia. Such mutations lead to decreased plasma and cerebrospinal fluid levels of progranulin (PGRN), a neurotrophic factor with lysosomal functions. Sortilin is a negative regulator of extracellular PGRN levels and has shown promise as a therapeutic target for frontotemporal dementia, enabling increased extracellular PGRN levels through inhibition of sortilin-mediated PGRN degradation. Here we report the development of a high-affinity sortilin-binding affibody-peptide fusion construct capable of increasing extracellular PGRN levels in vitro. By genetic fusion of a sortilin-binding affibody generated through phage display and a peptide derived from the progranulin C-terminus, an affinity protein (A3-PGRNC15*) with 185-pM affinity for sortilin was obtained. Treating PGRN-secreting and sortilin-expressing human glioblastoma U-251 cells with the fusion protein increased extracellular PGRN levels up to 2.5-fold, with an EC50 value of 1.3 nM. Our results introduce A3-PGRNC15* as a promising new agent with therapeutic potential for the treatment of frontotemporal dementia. Furthermore, the work highlights means to increase binding affinity through synergistic contribution from two orthogonal polypeptide units.

Research trends and hotspots for frontotemporal dementia from 2000 to 2022: a bibliometric analysis

Background

Frontotemporal dementia (FTD) is a neurodegenerative disease with clinical, pathological, and genetic heterogeneity. FTD is receiving increasing attention because it is the second leading cause of early-onset dementia after Alzheimer's disease. This study aimed to analyse the research trends and hotspots of FTD from 2000 to 2022 using bibliometrics.

Methods

Papers related to FTD from 2000 to 2020 were systematically searched through the Web of Science Core Collection (WOSCC). Citespace and Vosviewer software were used to visually analyse the retrieved data of countries/regions, institutions, journals, authors, references, and keywords. Microsoft Excel was used to generate the annual publications and growth trends.

Results

There were 10,227 papers included in the bibliometric analysis. The annual publication output on FTD has increased significantly from 2000 to 2022, with papers published in 934 academic journals and 87 countries/regions. The Journal of Alzheimer's Disease was the most popular, with 488 papers about FTD. The most productive countries/regions, institutions, and authors are the United States (n = 4,037), the University of California San Francisco (n = 687), and Miller, Bruce L. (n = 427), respectively. The article by Katya Rascovsky and her colleagues published on Brain in 2011 was the most cocited paper, with 625 citations. The research hotspots in this field were the clinical diagnostic criteria, subdivision, and pathological mechanism of FTD, such as tau protein, chromosome 17, progranulin, TDP-43, and C9orf72.

Conclusion

The future research direction is based on biomarkers and pathological mechanisms to diagnose and differential diagnose FTD from the aspects of behavior, neuropathology, neuroimaging, and serum markers.

G272V and P301L Mutations Induce Isoform Specific Tau Mislocalization to Dendritic Spines and Synaptic Dysfunctions in Cellular Models of 3R and 4R Tau Frontotemporal Dementia

Tau pathologies are detected in the brains of some of the most common neurodegenerative diseases including Alzheimer's disease (AD), Lewy body dementia (LBD), chronic traumatic encephalopathy (CTE), and frontotemporal dementia (FTD). Tau proteins are expressed in six isoforms with either three or four microtubule-binding repeats (3R tau or 4R tau) due to alternative RNA splicing. AD, LBD, and CTE brains contain pathological deposits of both 3R and 4R tau. FTD patients can exhibit either 4R tau pathologies in most cases or 3R tau pathologies less commonly in Pick's disease, which is a subfamily of FTD. Here, we report the isoform-specific roles of tau in FTD. The P301L mutation, linked to familial 4R tau FTD, induces mislocalization of 4R tau to dendritic spines in primary hippocampal cultures that were prepared from neonatal rat pups of both sexes. Contrastingly, the G272V mutation, linked to familial Pick's disease, induces phosphorylation-dependent mislocalization of 3R tau but not 4R tau proteins to dendritic spines. The overexpression of G272V 3R tau but not 4R tau proteins leads to the reduction of dendritic spine density and suppression of mEPSCs in 5-week-old primary rat hippocampal cultures. The decrease in mEPSC amplitude caused by G272V 3R tau is dynamin-dependent whereas that caused by P301L 4R tau is dynamin-independent, indicating that the two tau isoforms activate different signaling pathways responsible for excitatory synaptic dysfunction. Our 3R and 4R tau studies here will shed new light on diverse mechanisms underlying FTD, AD, LBD, and CTE.

The association between SII and aging: evidence from NHANES 1999-2018

Background

The study aimed to examine the association between the systemic immune-inflammation index (SII), a contemporary metric of systemic inflammatory response, and biological aging, which are closely interconnected processes.

Methods

This cross-sectional study utilized 10 cycles of data from the NHANES database spanning from 1990 to 2018. The study examined the relationship between the SII index, calculated as P * N/L, where P represents preoperative peripheral platelet count, N represents neutrophil count, and L represents lymphocyte count, and biological aging. Biological aging was assessed through various methods, such as phenotypic age, phenotypic age acceleration (PhenoAgeAccel), biological age, and biological age acceleration (BioAgeAccel). Correlations were analyzed using weighted linear regression and subgroup analysis.

Results

Among the 7,491 participants analyzed, the average age was 45.26 ± 0.34 years, with 52.16% being female. The average phenotypic and biological ages were 40.06 ± 0.36 and 45.89 ± 0.32 years, respectively. Following adjustment for potential confounders, elevated SII scores were linked to increased phenotypic age, biological age, Phenotypic age acceleration, and Biological age acceleration. Positive correlations were observed between health behavior and health factor scores and biological aging, with stronger associations seen for health factors. In health factor-specific analyses, the β coefficient was notably higher for high BMI. The robust positive associations between SII scores and both phenotypic age and biological age in the stratified analyses were consistently observed across all strata.

Conclusion

The evidence from the NHANES data indicate that SII may serve as a valuable marker for assessing different facets of aging and health outcomes, such as mortality and the aging process. Additional research is warranted to comprehensively elucidate the implications of SII in the aging process and its utility as a clinical instrument for evaluating and addressing age-related ailments.

Post-diagnostic support for persons with young-onset dementia - a retrospective analysis based on data from the Swedish dementia registry SveDem

BACKGROUND

Approximately 3.9 million persons worldwide have young-onset dementia. Symptoms related to young-onset dementia present distinct challenges related to finances, employment, and family. To provide tailored support, it is important to gain knowledge about the formal support available for persons with young-onset dementia. Therefore, this paper aims to describe formal support for persons with young-onset dementia in Sweden and the factors influencing this support.

METHODS

This retrospective study used data on persons under 65 years of age (n = 284) from The Swedish Registry for Cognitive/Dementia Disorders (SveDem) between 2021 and 2022. SveDem was established to monitor the quality of dementia care in Sweden. Characteristics of participants were obtained, including age, sex, dementia diagnosis, MMSE, medications, accommodation, and care setting. Descriptive statistics and logistic regression were used to test for associations between participant characteristics and post-diagnostic support.

RESULTS

Information and educational support were usually offered to the person with young-onset dementia (90.1%) and their family (78.9%). Approximately half of the sample were offered contact with a dementia nurse (49.3%), counsellor (51.4%), or needs assessor (47.9%). A minority (28.5%) were offered cognitive aids. Six regression models were conducted based on participant characteristics to predict the likelihood that persons were offered support. Support was not predicted by age, sex, children at home, accommodation, or medications. Lower MMSE scores (p < .05) and home help (p < .05) were significantly associated with offer of a needs assessor. Living together was a significant predictor (p < .01) for information and educational support offered to the family. Care setting significantly predicted (p < .01) an offer of information and educational support for the person and family members, as well as contact with a counsellor.

CONCLUSION

This study indicates potential formal support shortages for persons with young-onset dementia in some areas of dementia care. Despite equal support across most characteristics, disparities based on care setting highlight the importance of specialised dementia care. Pre-diagnostic support is minimal, indicating challenges for persons with young-onset dementia to access these services before diagnosis. While our study has identified areas in need of improvement, we recommend further research to understand the changing support needs of those with young-onset dementia.

Induced Pluripotent Stem Cells and Organoids in Advancing Neuropathology Research and Therapies

This review delves into the groundbreaking impact of induced pluripotent stem cells (iPSCs) and three-dimensional organoid models in propelling forward neuropathology research. With a focus on neurodegenerative diseases, neuromotor disorders, and related conditions, iPSCs provide a platform for personalized disease modeling, holding significant potential for regenerative therapy and drug discovery. The adaptability of iPSCs, along with associated methodologies, enables the generation of various types of neural cell differentiations and their integration into three-dimensional organoid models, effectively replicating complex tissue structures in vitro. Key advancements in organoid and iPSC generation protocols, alongside the careful selection of donor cell types, are emphasized as critical steps in harnessing these technologies to mitigate tumorigenic risks and other hurdles. Encouragingly, iPSCs show promising outcomes in regenerative therapies, as evidenced by their successful application in animal models.

Considering inequities in national dementia strategies: breadth, depth, and scope

BACKGROUND

Considering that dementia is an international public health priority, several countries have developed national dementia strategies outlining initiatives to address challenges posed by the disease. These strategies aim to improve the care, support, and resources available to meet the needs of persons living with dementia and their care partners and communities. Despite the known impact of social determinants of health on dementia risk, care, and outcomes, it is unclear whether dementia strategies adequately address related inequities. This study aimed to describe whether and how national dementia strategies considered inequities associated with social determinants of health.

METHODS

We conducted an environmental scan of the national dementia strategies of countries that are part of the Organisation for Economic Cooperation and Development (OECD). Included strategies had to be accessible in English or French. Sub-national or provincial plans were excluded. We synthesised information on strategies' considerations of inequity through a thematic analysis.

RESULTS

Of the 15 dementia strategies that met inclusion criteria, 13 mentioned at least one inequity (M = 2.4, median = 2, range:0-7) related to Race/Ethnicity; Religion; Age; Disability; Sexual Orientation/Gender Identity; Social Class; or Rurality. Age and disability were mentioned most frequently, and religion most infrequently. Eleven strategies included general inequity-focused objectives, while only 5 had specific inequity-focused objectives in the form of tangible percentage changes, deadlines, or allocated budgets for achieving equity-related goals outlined in their strategies.

CONCLUSIONS

Understanding if and how countries consider inequities in their dementia strategies enables the development of future strategies that adequately target inequities of concern. While most of the strategies mentioned inequities, few included tangible objectives to reduce them. Countries must not only consider inequities at a surface-level; rather, they must put forth actionable objectives that intend to lessen the impact of inequities in the care of all persons living with dementia.

Amyloid-induced neurodegeneration: A comprehensive review through aggregomics perception of proteins in health and pathology

Amyloidosis of protein caused by fibrillation and aggregation are some of the most exciting new edges not only in protein sciences but also in molecular medicines. The present review discusses recent advancements in the field of neurodegenerative diseases and therapeutic applications with ongoing clinical trials, featuring new areas of protein misfolding resulting in aggregation. The endogenous accretion of protein fibrils having fibrillar morphology symbolizes the beginning of neuro-disorders. Prognostic amyloidosis is prominent in numerous degenerative infections such as Alzheimer's and Parkinson's disease, Amyotrophic lateral sclerosis (ALS), etc. However, the molecular basis determining the intracellular or extracellular evidence of aggregates, playing a significant role as a causative factor in neurodegeneration is still unclear. Structural conversions and protein self-assembly resulting in the formation of amyloid oligomers and fibrils are important events in the pathophysiology of the disease. This comprehensive review sheds light on the evolving landscape of potential treatment modalities, highlighting the ongoing clinical trials and the potential socio-economic impact of novel therapeutic interventions in the realm of neurodegenerative diseases. Furthermore, many drugs are undergoing different levels of clinical trials that would certainly help in treating these disorders and will surely improve the socio-impact of human life.

Chronic high-dose dimenhydrinate use contributing to early multifactorial cognitive impairment

Dimenhydrinate is an over-the-counter antihistaminergic medication with anticholinergic properties used to treat nausea or motion sickness worldwide. There is a well-established correlation between the use of anticholinergic medications and dementia, however, it is unclear if a causal role exists. We report a case of minor neurocognitive disorder in a woman in her 40s with several years of high-dose daily dimenhydrinate abuse who subsequently developed significant delusional beliefs. Her clinical presentation was confounded by numerous other factors that could have impacted her cognition, such as a longstanding presumed learning disability, ankylosing spondylitis with adalimumab treatment, extensive cannabis use or potential development of a primary psychotic disorder. Her workup was within normal limits, and she has not responded to first-line antipsychotic medications to date. This case report adds to the growing evidence supporting concerns about potentially irreversible cognitive deficits in chronic misuse of anticholinergic agents, an association previously observed only in the elderly population.

Investigation of the Approaches to Optimal Exercise Interventions Based on Dementia Type: A Theoretical Review

The aim of this study is to enhance comprehension of the different types and features of dementia, including their symptoms, diagnosis and medical treatment, and to propose various evidence-based exercise interventions and their clinical applications tailored to each specific type of dementia. The theoretical review includes the analysis of publications in the scientific databases PubMed/Medline, Ebsco, Scielo, and Google. A total of 177 articles were found, of which 84 were studied in depth. With the prevalence of all forms of dementia projected to increase from 57.4 million in 2019 to 152.8 million in 2050, personalized treatment strategies are needed. This review discusses various forms of dementia, including their pathologies, diagnostic criteria, and prevalence rates. The importance of accurate diagnosis and tailored care is emphasized, as well as the effectiveness of physical exercise in improving cognitive function in dementia patients. For Alzheimer's, a combination of drug therapies and exercises is recommended to enhance cerebral blood flow and neurotransmitter activity. To improve cognitive and motor functions in Lewy body dementia, a combination of pharmacological and physical therapies is recommended. For managing frontotemporal dementia, a mix of medication and exercises aimed at emotion regulation, including aerobic exercises, and a unified protocol, is suggested. For mild cognitive impairment, aerobic and functional exercises are important in delaying cognitive decline and enhancing cognitive performance. In conclusion, individualized care and treatment plans tailored to the specific characteristics of each disease type can improve the quality of life for individuals with this condition and effectively manage this growing global health issue.

Determinants of Time to Diagnosis in Young-Onset Dementia

Timely diagnosis of young-onset dementia (YOD) is critical. This study aimed to identify factors that increased time to diagnosis at each stage of the diagnostic pathway. Participants were patients diagnosed with YOD (n = 40) and their care partners (n = 39). Information was obtained from questionnaires, and review of medical records. Mean time from symptom onset to YOD diagnosis was 3.6 ± 2 years. Suspicion of depression/anxiety at presentation was associated with significantly increased time from presentation to specialist referral. Neurologist-diagnosed YOD was the fastest route to a diagnosis, whereas diagnoses made by other specialists significantly increased the time from first specialist visit to diagnosis. By investigating multiple stages of the diagnostic pathway, we identified two factors that increased time to diagnosis: suspicion of depression/anxiety at presentation delayed specialist referral from primary care, and diagnosis by a specialist other than a neurologist delayed diagnosis of YOD.

[Clinical and morphologic characterization of Pick's dementia: case report and review of the literature]

Diseases morphologically characterized by frontotemporal lobar degeneration have relatively recently been considered as a group of frontotemporal dementias. This group is characterized by a tendency to early clinical onset of dementia, common genetic and morphological features, as well as a possible association with diseases such as amyotrophic lateral sclerosis and atypical parkinsonism syndrome. Historically, Pick's dementia (Pick's disease) was described as the first of the frontotemporal dementias, which is morphologically characterized by the presence of argyrophilic Pick's bodies represented by 3R-tau protein in the neurons of the cerebral cortex. Despite the characteristic clinical and morphological picture due to the relative rarity, the diagnosis of Pick's dementia is infrequently made by both clinicians and pathologists. The article presents current data on frontotemporal dementia. A case of Pick's dementia with characteristic clinical manifestations in the form of early onset of behavioral and personality disorders, as well as specific morphological changes in the brain, is described.

Connecting, learning, supporting: Caregivers' experiences of a stress and distress biopsychosocial group intervention

BACKGROUND

Family caregivers are fundamental in supporting people living with dementia to remain at home, however, psychological distress can occur as a result of their caring role. Research into interventions for caregivers of people living with young-onset dementia, including their experience of and the mediating processes of such interventions, remains limited.

METHODS

An Interpretative Phenomenological Analysis explored caregiver experiences and influence on caregiving of participating in a "Responding to Distress in Dementia" group. Five family caregivers were interviewed with discussions covering the period from first noticing symptoms to the interview session.

RESULTS

Within the group experience, four superordinate themes were identified: 'connecting to other caregivers', 'learning about caregiving', 'group factors' and 'reduced caregiver distress'. During the post-group period, three superordinate themes were recognised: 'maintaining support', 'applying learning', and 'normalising caregiving'.

CONCLUSIONS

The study highlighted several interrelated themes involving creating connections amongst caregivers with similar experiences, social learning, and supportive learning through group structure and facilitation. Many of the processes reflected those found in existing dementia caregiver intervention research. Recommendations included facilitating peer support groups and exploring whole-family approaches.

Cognitive impairment and the associated factors among women with a history of pregnancy complications in rural southwestern Uganda

BACKGROUND

Worldwide, there is a growing concern about the rising number of people with declining cognitive functioning. However, findings on this phenomenon are inconclusive. Our study aimed to assess the prevalence of cognitive impairment and the associated factors in women with a history of pregnancy complications in rural southwestern Uganda.

METHODS

This was a cross-sectional study carried out among women above 40 years of age in the greater Kabale district of southwestern Uganda between March and April 2022. Study participants were identified using a consecutive sampling method. Predictor variables included pregnancy complications and other social demographic factors that were assessed by semi-structured interviews while cognitive functioning as an outcome variable was assessed by Montreal Cognitive Assessment (MoCA-B) tool. Data were analyzed using STATA at a 95% Confidence level. Logistic regression analyses were selected for statistical modelling while odds ratios were calculated to assess the strength of associations between the predictor and outcome variables.

RESULTS

In total, 75% (212/280) of participants had some form of cognitive impairment, with 45% (123/280) falling into mild CI, 31% (86/280) moderate CI and 4% (10/280) severe CI. Twenty-three percent (68/280) of participants fell into category of normal cognitive functioning. Participants with >65 years of age had higher odds of developing cognitive impairment (OR = 2.94; 95%CI: 0.96-9.04, p = 0.06) than those with < 65 years of age. Protective factors to cognitive impairment include delivering from a health facility (OR = 0.31,95% CI:0.16-0.60, p = < .001), primary and post primary levels of education (OR = 0.05; 95% CI: 0.02-0.13, p<0.001, OR = 0.04; 95%CI: 0.02-0.23, p<0.001) respectively.

CONCLUSION

Results from this study show a high prevalence of cognitive impairment among women with a history of pregnancy complications in rural southwestern Uganda. Interventions geared toward preventing cognitive impairment among females with a history of pregnancy complications should be emphasized.

New cases of dementia are rising in elderly populations in Wales, UK

Dementia is one of the most common diseases in elderly populations, and older populations are one of the fastest growing groups globally. Consequently, the number of people developing and living with dementia is likely to grow. Using longitudinal medical records from Wales, UK between 1999 and 2018, diagnoses of overall dementia and common subtypes were combined with demographic data to assess numbers of new and existing cases per year. Data extraction resulted in 161,186 diagnoses from 116,645 individuals. Mean age at diagnosis of dementia increased over this period, resulting in fewer younger people with the disease. New cases of dementia have risen, as has the number of people living with dementia. Individuals with dementia are also living longer, even accounting for their older age. This may present a challenge for healthcare systems as the number of elderly people living with dementia is expected to continue to grow.

Exploratory Longitudinal Study of Ocular Structural and Visual Functional Changes in Subjects at High Genetic Risk of Developing Alzheimer's Disease

This study aimed to analyze the evolution of visual changes in cognitively healthy individuals at risk for Alzheimer's disease (AD). Participants with a first-degree family history of AD (FH+) and carrying the Ε4+ allele for the ApoE gene (ApoE ε4+) underwent retinal thickness analysis using optical coherence tomography (OCT) and visual function assessments, including visual acuity (VA), contrast sensitivity (CS), color perception, perception digital tests, and visual field analysis. Structural analysis divided participants into FH+ ApoE ε4+ and FH- ApoE ε4- groups, while functional analysis further categorized them by age (40-60 years and over 60 years). Over the 27-month follow-up, the FH+ ApoE ε4+ group exhibited thickness changes in all inner retinal layers. Comparing this group to the FH- ApoE ε4- group at 27 months revealed progressing changes in the inner nuclear layer. In the FH+ ApoE ε4+ 40-60 years group, no progression of visual function changes was observed, but an increase in VA and CS was maintained at 3 and 12 cycles per degree, respectively, compared to the group without AD risk at 27 months. In conclusion, cognitively healthy individuals at risk for AD demonstrated progressive retinal structural changes over the 27-month follow-up, while functional changes remained stable.

Dementia incidence and population-attributable fraction for dementia risk factors in Republic of Korea: a 12-year longitudinal follow-up study of a national cohort

Background

We aimed to investigate the incidence of dementia by age and year as well as the population-attributable fractions (PAFs) for known dementia risk factors in Republic of Korea.

Methods

A 12-year, nationwide, population-based, retrospective cohort study was conducted. We used customized health information from the National Health Insurance Service (NHIS) data from 2002 to 2017. We analyzed age- and sex-adjusted incidence rates and PAF of dementia for each risk factor such as depression, diabetes, hemorrhagic stroke, ischemic stroke, hypertension, osteoporosis and physical inactivity using Levin's formula.

Results

Of the 794,448 subjects in the dementia-free cohort, 49,524 (6.2%) developed dementia. Dementia incidence showed annual growth from 1.56 per 1,000 person-years in 2006 to 6.94 per 1,000 person-years in 2017. Of all dementia cases, 34,544 subjects (69.8%) were female and 2,479 subjects (5.0%) were early onset dementia. AD dementia accounted for 66.5% of the total dementia incidence. Considering relative risk and prevalence, physical inactivity attributed the greatest to dementia (PAF, 8.1%), followed by diabetes (PAF, 4.2%), and hypertension (PAF, 2.9%). Altogether, the significant risk factors increased the risk of dementia by 18.0% (overall PAF).

Conclusion

We provided the incidence of dementia and PAFs for dementia risk factors in Republic of Korea using a 12-year, nationwide cohort. Encouraging lifestyle modifications and more aggressive control of risk factors may effectively prevent dementia.

Advances in the treatment and management of frontotemporal dementia

INTRODUCTION

Frontotemporal dementia (FTD) is a complex neurodegenerative disorder, characterized by a wide range of pathological conditions associated with the buildup of proteins such as tau and TDP-43. With a strong hereditary component, FTD often results from genetic variants in three genes - MAPT, GRN, and C9orf72.

AREAS COVERED

In this review, the authors explore abnormal protein accumulation in FTD and forthcoming treatments, providing a detailed analysis of new diagnostic advancements, including innovative markers. They analyze how these discoveries have influenced therapeutic strategies, particularly disease-modifying treatments, which could potentially transform FTD management. This comprehensive exploration of FTD from its molecular underpinnings to its therapeutic prospects offers a compelling overview of the current state of FTD research.

EXPERT OPINION

Notable challenges in FTD management involve identifying reliable biomarkers for early diagnosis and response monitoring. Genetic forms of FTD, particularly those linked to C9orf72 and GRN, show promise, with targeted therapies resulting in substantial progress in disease-modifying strategies. The potential of neuromodulation techniques, like tDCS and rTMS, is being explored, requiring further study. Ongoing trials and multi-disciplinary care highlight the continued push toward effective FTD treatments. With increasing understanding of FTD's molecular and clinical intricacies, the hope for developing effective interventions grows.

Outdoor artificial light at night and risk of early-onset dementia: A case-control study in the Modena population, Northern Italy

Background

Dementia is a neurological syndrome characterized by severe cognitive impairment with functional impact on everyday life. It can be classified as young onset dementia (EOD) in case of symptom onset before 65, and late onset dementia (LOD). The purpose of this study is to assess the risk of dementia due to light pollution, and specifically outdoor artificial light at night (LAN).

Methods

Using a case-control design, we enrolled dementia patients newly-diagnosed in the province of Modena in the period 2017-2019 and a referent population from their caregivers. We geo-referenced the address of residence on the date of recruitment, provided it was stable for the previous five years. We assessed LAN exposure through 2015 nighttime luminance satellite images from the Visible Infrared Imaging Radiometer Suite (VIIRS). Using a logistic regression model adjusted for age, sex, and education, we calculated the risk of dementia associated with increasing LAN exposure, namely using <10 nW/cm²/sr as reference and considering ≥10-<40 nW/cm²/sr intermediate and ≥40 nW/cm²/sr high exposure, respectively We also implemented non-linear assessment using a spline regression model.

Results

We recruited 58 EOD cases, 34 LOD cases and 54 controls. Average LAN exposure levels overlapped for EOD cases and controls, while LOD cases showed higher levels. Compared with the lowest exposure, the risk of EOD associated with LAN was higher in the intermediate exposure (OR = 1.36, 95% CI 0.54-3.39), but not in the high exposure category (OR = 1.04, 95% CI 0.32-3.34). In contrast, the risk of LOD was positively associated with LAN exposure, with ORs of 2.58 (95% CI 0.26-25.97) and 3.50 (95% CI 0.32-38.87) in the intermediate and high exposure categories, respectively. The spline regression analysis showed substantial lack of association between LAN and EOD, while almost linear although highly imprecise association emerged for LOD.

Conclusions

Although the precision of the estimates was affected by the limited sample size and the study design did not allow us to exclude the presence of residual confounding, these results suggest a possible role of LAN in the etiology of dementia, particularly of its late-onset form.

The mental health of rural older adults: the role of the built environment in Jintang County

The mental health of older adults has become one of the major health challenges facing society today, which has attracted wide concerns from scholars in urban areas, but research in rural areas has been neglected. Therefore, this paper took rural older adult residents of 11 sample villages in Jintang County, Chengdu City, Sichuan Province, as the research object. After controlling the demographic characteristics of older adults in rural areas, this paper attempted to explore the effects of the rural built Environment on the mental health of older adults. Through field investigation in the sample villages, 515 valid questionnaires were obtained. The results from the Binary Logistic Regression Model show that good marital status, physical health, education level, well-constructed roads, and safe neighborhoods had significant positive effects on the mental health of rural older adults. Rural older adults who prefer to walk, cycle, and use public transport have better mental health, and accessibility to the periodic market, health station, bus station, village committee, supermarket, and the main road is positively correlated with the mental health of rural older adults, while the distance from home to the town center and coach terminal has a significant negative impact on the mental health of rural older adults. The research results provide a theoretical reference for further construction of rural aging environments.

Multi-domain prognostic models used in middle-aged adults without known cognitive impairment for predicting subsequent dementia

BACKGROUND

Dementia, a global health priority, has no current cure. Around 50 million people worldwide currently live with dementia, and this number is expected to treble by 2050. Some health conditions and lifestyle behaviours can increase or decrease the risk of dementia and are known as 'predictors'. Prognostic models combine such predictors to measure the risk of future dementia. Models that can accurately predict future dementia would help clinicians select high-risk adults in middle age and implement targeted risk reduction.

OBJECTIVES

Our primary objective was to identify multi-domain prognostic models used in middle-aged adults (aged 45 to 65 years) for predicting dementia or cognitive impairment. Eligible multi-domain prognostic models involved two or more of the modifiable dementia predictors identified in a 2020 Lancet Commission report and a 2019 World Health Organization (WHO) report (less education, hearing loss, traumatic brain injury, hypertension, excessive alcohol intake, obesity, smoking, depression, social isolation, physical inactivity, diabetes mellitus, air pollution, poor diet, and cognitive inactivity). Our secondary objectives were to summarise the prognostic models, to appraise their predictive accuracy (discrimination and calibration) as reported in the development and validation studies, and to identify the implications of using dementia prognostic models for the management of people at a higher risk for future dementia.

SEARCH METHODS

We searched MEDLINE, Embase, PsycINFO, CINAHL, and ISI Web of Science Core Collection from inception until 6 June 2022. We performed forwards and backwards citation tracking of included studies using the Web of Science platform.  SELECTION CRITERIA: We included development and validation studies of multi-domain prognostic models. The minimum eligible follow-up was five years. Our primary outcome was an incident clinical diagnosis of dementia based on validated diagnostic criteria, and our secondary outcome was dementia or cognitive impairment determined by any other method.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references, extracted data using a template based on the CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies (CHARMS), and assessed risk of bias and applicability of included studies using the Prediction model Risk Of Bias ASsessment Tool (PROBAST). We synthesised the C-statistics of models that had been externally validated in at least three comparable studies.  MAIN RESULTS: We identified 20 eligible studies; eight were development studies and 12 were validation studies. There were 14 unique prognostic models: seven models with validation studies and seven models with development-only studies. The models included a median of nine predictors (range 6 to 34); the median number of modifiable predictors was five (range 2 to 11). The most common modifiable predictors in externally validated models were diabetes, hypertension, smoking, physical activity, and obesity. In development-only models, the most common modifiable predictors were obesity, diabetes, hypertension, and smoking. No models included hearing loss or air pollution as predictors. Nineteen studies had a high risk of bias according to the PROBAST assessment, mainly because of inappropriate analysis methods, particularly lack of reported calibration measures. Applicability concerns were low for 12 studies, as their population, predictors, and outcomes were consistent with those of interest for this review. Applicability concerns were high for nine studies, as they lacked baseline cognitive screening or excluded an age group within the range of 45 to 65 years. Only one model, Cardiovascular Risk Factors, Ageing, and Dementia (CAIDE), had been externally validated in multiple studies, allowing for meta-analysis. The CAIDE model included eight predictors (four modifiable predictors): age, education, sex, systolic blood pressure, body mass index (BMI), total cholesterol, physical activity and APOEƐ4 status. Overall, our confidence in the prediction accuracy of CAIDE was very low; our main reasons for downgrading the certainty of the evidence were high risk of bias across all the studies, high concern of applicability, non-overlapping confidence intervals (CIs), and a high degree of heterogeneity. The summary C-statistic was 0.71 (95% CI 0.66 to 0.76; 3 studies; very low-certainty evidence) for the incident clinical diagnosis of dementia, and 0.67 (95% CI 0.61 to 0.73; 3 studies; very low-certainty evidence) for dementia or cognitive impairment based on cognitive scores. Meta-analysis of calibration measures was not possible, as few studies provided these data.

AUTHORS' CONCLUSIONS

We identified 14 unique multi-domain prognostic models used in middle-aged adults for predicting subsequent dementia. Diabetes, hypertension, obesity, and smoking were the most common modifiable risk factors used as predictors in the models. We performed meta-analyses of C-statistics for one model (CAIDE), but the summary values were unreliable. Owing to lack of data, we were unable to meta-analyse the calibration measures of CAIDE. This review highlights the need for further robust external validations of multi-domain prognostic models for predicting future risk of dementia in middle-aged adults.

What Can Economics Say about Alzheimer's Disease?

Alzheimer's disease (AD) affects one in ten people aged 65 or older and is the most expensive disease in the United States. We describe the central economic questions raised by AD. Although there is overlap with the economics of aging and health, the defining feature of the "economics of Alzheimer's disease" is an emphasis on choice by cognitively impaired patients that affects health and financial well-being, and situations in which dynamic contracts between patients and caregivers are useful but difficult to enforce. A focus on innovation in AD prevention, treatment, and care is also critical given the enormous social cost of AD and present lack of understanding of its causes, which raises questions of optimal resource allocation and alignment of private and social incentives. The enormous scope for economists to contribute to our understanding of AD-related issues including drug development, efficient care delivery, dynamic contracting, long-term care risk, financial decision-making, and the design of public programs for AD suggests a rich research program for many areas of economics.

Astrocyte dysfunction and neuronal network hyperactivity in a CRISPR engineered pluripotent stem cell model of frontotemporal dementia

Frontotemporal dementia (FTD) is the second most prevalent type of early-onset dementia and up to 40% of cases are familial forms. One of the genes mutated in patients is CHMP2B, which encodes a protein found in a complex important for maturation of late endosomes, an essential process for recycling membrane proteins through the endolysosomal system. Here, we have generated a CHMP2B-mutated human embryonic stem cell line using genome editing with the purpose to create a human in vitro FTD disease model. To date, most studies have focused on neuronal alterations; however, we present a new co-culture system in which neurons and astrocytes are independently generated from human embryonic stem cells and combined in co-cultures. With this approach, we have identified alterations in the endolysosomal system of FTD astrocytes, a higher capacity of astrocytes to uptake and respond to glutamate, and a neuronal network hyperactivity as well as excessive synchronization. Overall, our data indicates that astrocyte alterations precede neuronal impairments and could potentially trigger neuronal network changes, indicating the important and specific role of astrocytes in disease development.

Proteomics analysis of prefrontal cortex of Alzheimer's disease patients revealed dysregulated proteins in the disease and novel proteins associated with amyloid-β pathology

BACKGROUND

Alzheimer's disease (AD) is a progressive, chronic, and neurodegenerative disease, and the most common cause of dementia worldwide. Currently, the mechanisms underlying the disease are far from being elucidated. Thus, the study of proteins involved in its pathogenesis would allow getting further insights into the disease and identifying new markers for AD diagnosis.

METHODS

We aimed here to analyze protein dysregulation in AD brain by quantitative proteomics to identify novel proteins associated with the disease. 10-plex TMT (tandem mass tags)-based quantitative proteomics experiments were performed using frozen tissue samples from the left prefrontal cortex of AD patients and healthy individuals and vascular dementia (VD) and frontotemporal dementia (FTD) patients as controls (CT). LC-MS/MS analyses were performed using a Q Exactive mass spectrometer.

RESULTS

In total, 3281 proteins were identified and quantified using MaxQuant. Among them, after statistical analysis with Perseus (p value < 0.05), 16 and 155 proteins were defined as upregulated and downregulated, respectively, in AD compared to CT (Healthy, FTD and VD) with an expression ratio ≥ 1.5 (upregulated) or ≤ 0.67 (downregulated). After bioinformatics analysis, ten dysregulated proteins were selected as more prone to be associated with AD, and their dysregulation in the disease was verified by qPCR, WB, immunohistochemistry (IHC), immunofluorescence (IF), pull-down, and/or ELISA, using tissue and plasma samples of AD patients, patients with other dementias, and healthy individuals.

CONCLUSIONS

We identified and validated novel AD-associated proteins in brain tissue that should be of further interest for the study of the disease. Remarkably, PMP2 and SCRN3 were found to bind to amyloid-β (Aβ) fibers in vitro, and PMP2 to associate with Aβ plaques by IF, whereas HECTD1 and SLC12A5 were identified as new potential blood-based biomarkers of the disease.

Brain Kynurenine Pathway Metabolite Levels May Reflect Extent of Neuroinflammation in ALS, FTD and Early Onset AD

OBJECTIVES

Despite distinct clinical profiles, amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) patients share a remarkable portion of pathological features, with a substantial percentage of patients displaying a mixed disease phenotype. Kynurenine metabolism seems to play a role in dementia-associated neuroinflammation and has been linked to both diseases. We aimed to explore dissimilarities in kynurenine pathway metabolites in these early onset neurodegenerative disorders in a brain-region-specific manner.

METHODS

Using liquid chromatography mass spectrometry (LC-MS/MS), kynurenine metabolite levels were determined in the brain samples of 98 healthy control subjects (n = 20) and patients with early onset Alzheimer's disease (EOAD) (n = 23), ALS (n = 20), FTD (n = 24) or a mixed FTD-ALS (n = 11) disease profile.

RESULTS

Overall, the kynurenine pathway metabolite levels were significantly lower in patients with ALS compared to FTD, EOAD and control subjects in the frontal cortex, substantia nigra, hippocampus and neostriatum. Anthranilic acid levels and kynurenine-to-tryptophan ratios were consistently lower in all investigated brain regions in ALS compared to the other diagnostic groups.

CONCLUSIONS

These results suggest that the contribution of kynurenine metabolism in neuroinflammation is lower in ALS than in FTD or EOAD and may also be traced back to differences in the age of onset between these disorders. Further research is necessary to confirm the potential of the kynurenine system as a therapeutic target in these early onset neurodegenerative disorders.

The Behavioural Dysfunction Questionnaire discriminates behavioural variant frontotemporal dementia from Alzheimer's disease dementia and major depressive disorder

BACKGROUND AND OBJECTIVES

Early-stage behavioural variant frontotemporal dementia (bvFTD) is often misdiagnosed, highlighting the need for new diagnostic instruments. Based on the revised diagnostic criteria for bvFTD, we developed the Behavioural Dysfunction Questionnaire (BDQ). In this explorative study, we aimed to determine the best scoring and analytical method for the BDQ to discriminate between bvFTD and non-bvFTD patients.

MATERIALS AND METHODS

34 patients with early-stage bvFTD, 56 with early-stage Alzheimer's disease dementia (ADD) and 41 with major depressive disorder (MDD) were recruited. We calculated BDQ-items with or without inclusion of a time criterion: (a) without time criterion, (b) with 10 years' time criterion (symptom presence less than 10 years), and (c) with 3 years' time criterion (symptom presentation within the first 3 years). Using these three differently calculated items, we generated six variables, i.e. 3*2 [BDQ-Global Score (BDQ-GS; domains average score); BDQ-Global Domain Score (BDQ-GDS; domains categorical score)]. Then, we performed univariate and bivariate (BDQ-GS and BDQ-GDS combined) ROC analyses.

RESULTS

Models including BDQ-GS, BDQ-GDS or both variables combined discriminated similarly between groups. In contrast, models without time criterion or with 10 years' time criterion discriminated better than models including variables with 3 years' time criterion. These models discriminated highly (AUC = 85.98-87.78) between bvFTD and MDD and bvFTD and ADD, respectively.

CONCLUSION

BDQ-scores without any time criterion discriminated highly between early-stage bvFTD and non-bvFTD groups, which could improve the early diagnosis of bvFTD. With its standardised procedure, the BDQ is also appropriate for repeated assessments.

Dementia in the incarcerated population: a retrospective study using the South Carolina Alzheimer's disease registry, USA

PURPOSE

Research about the prevalence of dementia among older adults in the incarceration system is currently lacking, and further investigation is warranted. Considering the high level of healthcare needs, unique behavioural issues and difficulty to rehabilitate within the system due to its punitive approach and lack of effective rehabilitation programs, further investigation is warranted to characterize and determine the number of incarcerated older adults with dementia. The purpose of this study is to estimate the prevalence of individuals with dementia in the prison system while also describing the incarceration, demographic and offence-related characteristics of this unique population.

DESIGN/METHODOLOGY/APPROACH

South Carolina (SC) Alzheimer's Disease and Related Dementias Registry (1992-2016) and South Carolina Department of Corrections (SCDC) data (Fiscal years 1992-2019) were cross-referenced. The prevalence of Alzheimer's disease and related dementias (ADRD) cases in the corrections system was calculated using South Carolina Alzheimer's Disease (SC AD) SC ADRD Registry and SCDC data. Pearson's correlation coefficients were calculated to determine strength and direction of relationships between year of incarceration and frequency of ADRD cases both prior to and after incarcerations, respectively. Significant differences by age group, race, gender and dementia type were determined using a two-tailed pooled t-test and Bonferroni approach where appropriate. Count data for types of crimes committed are also presented.

FINDINGS

The linkage showed that there were 2,171 individuals within the SC AD Registry who have been in the corrections system, about 1% of those in the Registry. Of these individuals, 1,930 cases were diagnosed with ADRD after incarceration and 241 prior to incarceration. In 2016, 317 individuals with ADRD were incarcerated. For ages 55 and above in South Carolina, the prevalence of ADRD is 6.7% in the general, non-incarcerated population compared to 14.4% in the incarcerated population. Additional results showed that those diagnosed with ADRD between 55 and 65 years of age had a significantly lower mean age at first incarceration (34.6 years of age) than those diagnosed between 66 and 74 years of age (55.9 years of age), indicating that those incarcerated earlier in life had an earlier dementia diagnosis. Additionally, African Americans had a significantly lower mean age at first incarceration (43.4 years of age) than Whites (46.2 years of age) and females had significantly lower mean age at first incarceration (42.9 years of age) than males (45 years of age). When investigating trends, results showed a significant positive linear association between year and frequency of ADRD diagnoses (p-value < 0.05) for those with ADRD diagnosis prior to incarceration and a significant decreasing linear association (p-value < 0.0001) in the number of individuals with an ADRD diagnosis after corrections. Findings also showed that a large percentage of older adults with ADRD in prison did not commit a violence offence.

ORIGINALITY/VALUE

This study links a population-based Alzheimer's disease registry and state-wide corrections data to estimate the prevalence of individuals with dementia in the prison system. This linkage presents an opportunity to fill in significant gaps and contribute to the body of literature on dementia among people in prison in the USA.

Autoimmunity and Frontotemporal Lobar Degeneration: From Laboratory Study to Clinical Practice

Frontotemporal lobar degeneration (FTLD) is a group of neurodegenerative diseases with heterogenous clinical, genetic, and pathological characteristics that show similar impairment of areas in the frontal and/or temporal lobes. Prime doctors' lack of awareness of this complex disease makes early identification and accurate intervention difficult. Autoimmune diseases and autoantibodies are manifestations of different levels of autoimmune reactions. This review presents research findings examining the relationship between autoimmunity and FTLD in terms of autoimmune diseases and autoantibodies with a focus on identifying potential diagnosis and treatment approaches. The findings indicate that the same or similar pathophysiological mechanisms may exist from clinical, genetic, and pathological perspectives. However, the existing evidence is not sufficient to extract substantial conclusions. On the basis of the current situation, we propose future research patterns using prospective studies on large populations and combined clinical and experimental research. Autoimmune reactions or, more generally, inflammatory reactions should receive increased attention from doctors and scientists of all disciplines.

Global incidence of young-onset dementia: A systematic review and meta-analysis

INTRODUCTION

Reliable data on the incidence rates for young-onset dementia (YOD) are lacking, but are necessary for research on disease etiology and to raise awareness among health care professionals.

METHODS

We performed a systematic review and meta-analysis on population-based studies on the incidence of YOD, published between January 1, 1990 and February 1, 2022, according to Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines. Data were analyzed using random-effects meta-analyses. Results were age-standardized, and heterogeneity was assessed by subgroup analyses and meta-regression.

RESULTS

Sixty-one articles were included. Global age-standardized incidence rates increased from 0.17/100,000 in age 30 to 34 years, to 5.14/100,000 in age 60 to 64 years, giving a global total age-standardized incidence rate of 11 per 100,000 in age 30 to 64. This corresponds to 370,000 new YOD cases annually worldwide. Heterogeneity was high and meta-regression showed geographic location significantly influenced this heterogeneity.

DISCUSSION

This meta-analysis shows the current best estimate of YOD incidence. New prospective cohort studies are needed.

Short-term associations between warm-season ambient temperature and emergency department visits for Alzheimer's disease and related dementia in five US states

BACKGROUND

Ambient temperatures are projected to increase in the future due to climate change. Alzheimer's disease (AD) and Alzheimer's disease-related dementia (ADRD) affect millions of individuals and represent substantial health burdens in the US. High temperature may be a risk factor for AD/ADRD outcomes with several recent studies reporting associations between temperature and AD mortality. However, the link between heat and AD morbidity is poorly understood.

METHODS

We examined short-term associations between warm-season daily ambient temperature and AD/ADRD emergency department (ED) visits for individuals aged 45 years or above during the warm season (May to October) for up to 14 years (2005-2018) in five US states: California, Missouri, North Carolina, New Jersey, and New York. Daily ZIP code-level maximum, average and minimum temperature exposures were derived from 1 km gridded Daymet products. Associations are assessed using a time-stratified case-crossover design using conditional logistic regression.

RESULTS

We found consistent positive short-term effects of ambient temperature among 3.4 million AD/ADRD ED visits across five states. An increase of the 3-day cumulative temperature exposure of daily average temperature from the 50th to the 95th percentile was associated with a pooled odds ratio of 1.042 (95% CI: 1.034, 1.051) for AD/ADRD ED visits. We observed evidence of the association being stronger for patients 65-74 years of age and for ED visits that led to hospital admissions. Temperature associations were also stronger among AD/ADRD ED visits compared to ED visits for other reasons, particularly among patients aged 65-74 years.

CONCLUSION

People with AD/ADRD may represent a vulnerable population affected by short-term exposure to high temperature. Our results support the development of targeted strategies to reduce heat-related AD/ADRD morbidity in the context of global warming.

Evaluation of Satisfaction with the Built Environment of University Buildings under the Epidemic and Its Impact on Student Anxiety

Anxiety on college campuses has increased due to the COVID-19 epidemic's profound effects on society. Much research has been conducted on how the built environment influences mental health; however, little has been undertaken on how it affects student mental health in the context of the epidemic from the architectural scale perspective of academic buildings. Based on online survey data, this study develops multiple linear regression and binary logistic regression models to investigate students' satisfaction ratings of the academic buildings' physical environments during the epidemic and how these satisfaction ratings affect students' anxiety tendencies. According to the study's findings regarding the natural exposure perspective, students who perceived the academic building's poor semi-open space view (p = 0.004, OR = 3.22) as unsatisfactory factors were more likely to show anxiety tendencies. In terms of the physical conditions, students who were dissatisfied with the noise level in the classroom (p = 0.038, OR = 0.616) and the summer heat in semi-open spaces (p = 0.031, OR = 2.38) were more likely to exhibit anxiety tendencies. Additionally, even after controlling for confusing distractions, the general satisfaction rating of the academic building's physical environments (p = 0.047, OR = 0.572) was still able to significantly and negatively affect students' anxiety tendencies. The study's findings can be used in the architectural and environmental planning of academic buildings focusing on mental health.