Differences in trajectories of quality of life according to type of dementia: 6-year longitudinal findings from the IDEAL programme.

BACKGROUND: People with different types of dementia may have distinct symptoms and experiences that affect their quality of life. This study investigated whether quality of life varied across types of dementia and over time. METHODS: The participants were 1555 people with mild-to-moderate dementia and 1327 carers from the IDEAL longitudinal cohort study, recruited from clinical services. As many as possible were followed for up to 6 years. Diagnoses included were Alzheimer's disease, vascular dementia, mixed Alzheimer's and vascular dementia, Parkinson's disease dementia, dementia with Lewy bodies, and frontotemporal dementia. Self- and informant-rated versions of the Quality of Life in Alzheimer's Disease scale were used. A joint model, incorporating a mixed effects model with random effects and a survival model to account for dropout, was used to examine whether quality of life varied by dementia type at the time of diagnosis and how trajectories changed over time. RESULTS: The strongest associations between dementia type and quality of life were seen around the time of diagnosis. For both self-ratings and informant ratings, people with Parkinson's disease dementia or dementia with Lewy bodies had lower quality of life scores. Over time there was little change in self-rated scores across all dementia types (- 0.15 points per year). Informant-rated scores declined over time (- 1.63 points per year), with the greatest decline seen in ratings by informants for people with dementia with Lewy bodies (- 2.18 points per year). CONCLUSIONS: Self-rated quality of life scores were relatively stable over time whilst informant ratings showed a steeper decline. People with Parkinson's disease dementia or dementia with Lewy bodies report particularly low levels of quality of life, indicating the importance of greater attention to the needs of these groups.

Disentangling and quantifying the relative cognitive impact of concurrent mixed neurodegenerative pathologies.

Neurodegenerative pathologies such as Alzheimer disease neuropathologic change (ADNC), Lewy body disease (LBD), limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC), and cerebrovascular disease (CVD) frequently coexist, but little is known about the exact contribution of each pathology to cognitive decline and dementia in subjects with mixed pathologies. We explored the relative cognitive impact of concurrent common and rare neurodegenerative pathologies employing multivariate logistic regression analysis adjusted for age, gender, and level of education. We analyzed a cohort of 6,262 subjects from the National Alzheimer's Coordinating Center database, ranging from 0 to 6 comorbid neuropathologic findings per individual, where 95.7% of individuals had at least 1 neurodegenerative finding at autopsy and 75.5% had at least 2 neurodegenerative findings. We identified which neuropathologic entities correlate most frequently with one another and demonstrated that the total number of pathologies per individual was directly correlated with cognitive performance as assessed by Clinical Dementia Rating (CDR®) and Mini-Mental State Examination (MMSE). We show that ADNC, LBD, LATE-NC, CVD, hippocampal sclerosis, Pick disease, and FTLD-TDP significantly impact overall cognition as independent variables. More specifically, ADNC significantly affected all assessed cognitive domains, LBD affected attention, processing speed, and language, LATE-NC primarily affected tests related to logical memory and language, while CVD and other less common pathologies (including Pick disease, progressive supranuclear palsy, and corticobasal degeneration) had more variable neurocognitive effects. Additionally, ADNC, LBD, and higher numbers of comorbid neuropathologies were associated with the presence of at least one APOE ε4 allele, and ADNC and higher numbers of neuropathologies were inversely correlated with APOE ε2 alleles. Understanding the mechanisms by which individual and concomitant neuropathologies affect cognition and the degree to which each contributes is an imperative step in the development of biomarkers and disease-modifying therapeutics, particularly as these medical interventions become more targeted and personalized.

Enhanced Spine Stability and Survival Lead to Increases in Dendritic Spine Density as an Early Response to Local Alpha-Synuclein Overexpression in Mouse Prefrontal Cortex.

Lewy Body Dementias (LBD), including Parkinson's disease dementia and Dementia with Lewy Bodies, are characterized by widespread accumulation of intracellular alpha-Synuclein protein deposits in regions beyond the brainstem, including in the cortex. However, the impact of local pathology in the cortex is unknown. To investigate this, we employed viral overexpression of human alpha-Synuclein protein targeting the mouse prefrontal cortex (PFC). We then used in vivo 2-photon microscopy to image awake head-fixed mice via an implanted chronic cranial window to assess the early consequences of alpha-Synuclein overexpression in the weeks following overexpression. We imaged apical tufts of Layer V pyramidal neurons in the PFC of Thy1-YFP transgenic mice at 1-week intervals from 1 to 2 weeks before and 9 weeks following viral overexpression, allowing analysis of dynamic changes in dendritic spines. We found an increase in the relative dendritic spine density following local overexpression of alpha-Synuclein, beginning at 5 weeks post-injection, and persisting for the remainder of the study. We found that alpha-Synuclein overexpression led to an increased percentage and longevity of newly-persistent spines, without significant changes in the total density of newly formed or eliminated spines. A follow-up study utilizing confocal microscopy revealed that the increased spine density is found in cortical cells within the alpha-Synuclein injection site, but negative for alpha-Synuclein phosphorylation at Serine-129, highlighting the potential for effects of dose and local circuits on spine survival. These findings have important implications for the physiological role and early pathological stages of alpha-Synuclein in the cortex.

Lewy body radius growth: The hypothesis of the cube root of time dependency.

This paper presents a model for the growth of Lewy bodies (LBs), which are pathological hallmarks of Parkinson's disease (PD). The model simulates the growth of classical LBs, consisting of a core and a halo. The core is assumed to comprise lipid membrane fragments and damaged organelles, while the halo consists of radiating alpha-synuclein (α-syn) fibrils. The Finke-Watzky model is employed to simulate the aggregation of lipid fragments and α-syn monomers. Analytical and numerical exploration of the governing equations yielded approximate solutions applicable for larger times. The application of these approximate solutions to simulate LB radius growth led to the discovery of the cube root hypothesis, which posits that the LB radius is proportional to the cube root of its growth time. Sensitivity analysis revealed that the LB radius is unaffected by the kinetic rates of nucleation and autocatalytic growth, with growth primarily regulated by the production rates of lipid membrane fragments and α-syn monomers. The model indicates that the formation of large LBs associated with PD is dependent on the malfunction of the machinery responsible for the degradation of lipid membrane fragments, α-syn monomers, and their aggregates.

Severe cholinergic terminal loss in newly diagnosed dementia with Lewy bodies.

Cholinergic changes play a fundamental role in the natural history of dementia with Lewy bodies and Lewy body disease in general. Despite important achievements in the field of cholinergic research, significant challenges remain. We conducted a study with four main objectives: (i) to examine the integrity of cholinergic terminals in newly diagnosed dementia with Lewy bodies; (ii) to disentangle the cholinergic contribution to dementia by comparing cholinergic changes in Lewy body patients with and without dementia; (iii) to investigate the in vivo relationship between cholinergic terminal loss and atrophy of cholinergic cell clusters in the basal forebrain at different stages of Lewy body disease; and (iv) to test whether any asymmetrical degeneration in cholinergic terminals would correlate with motor dysfunction and hypometabolism. To achieve these objectives, we conducted a comparative cross-sectional study of 25 newly diagnosed dementia with Lewy bodies patients (age 74 ± 5 years, 84% male), 15 healthy control subjects (age 75 ± 6 years, 67% male) and 15 Parkinson's disease patients without dementia (age 70 ± 7 years, 60% male). All participants underwent 18F-fluoroetoxybenzovesamicol PET and high-resolution structural MRI. In addition, we collected clinical 18F-fluorodeoxyglucose PET images. Brain images were normalized to standard space and regional tracer uptake and volumetric indices of basal forebrain degeneration were extracted. Patients with dementia showed spatially distinct reductions in cholinergic terminals across the cerebral cortex, limbic system, thalamus and brainstem. Also, cholinergic terminal binding in cortical and limbic regions correlated quantitatively and spatially with atrophy of the basal forebrain. In contrast, patients without dementia showed decreased cholinergic terminal binding in the cerebral cortex despite preserved basal forebrain volumes. In patients with dementia, cholinergic terminal reductions were most severe in limbic regions and least severe in occipital regions compared to those without dementia. Interhemispheric asymmetry of cholinergic terminals correlated with asymmetry of brain metabolism and lateralized motor function. In conclusion, this study provides robust evidence for severe cholinergic terminal loss in newly diagnosed dementia with Lewy bodies, which correlates with structural imaging measures of cholinergic basal forebrain degeneration. In patients without dementia, our findings suggest that loss of cholinergic terminal function occurs 'before' neuronal cell degeneration. Moreover, the study supports that degeneration of the cholinergic system is important for brain metabolism and may be linked with degeneration in other transmitter systems. Our findings have implications for understanding how cholinergic system pathology contributes to the clinical features of Lewy body disease, changes in brain metabolism and disease progression patterns.

Elevated serum LDL-C increases the risk of Lewy body dementia: a two-sample mendelian randomization study.

BACKGROUND: Lewy body dementia (LBD) ranks second among prevalent neurodegenerative dementias. Previous studies have revealed associations of serum lipid measures with several neurodegenerative diseases. Nevertheless, the potential connection between serum lipids and LBD remains undetermined. In this study, Mendelian randomization (MR) analyses were carried out to assess the causal relationships of several serum lipid measures with the risk of developing LBD. METHODS: Genome-wide association study (GWAS) data for serum lipids and LBD in European descent individuals were acquired from publicly available genetic summary data. A series of filtering procedures were conducted to identify the genetic variant candidates that are related to serum lipids, including high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). The causal effects were primarily determined through inverse-variance weighting (IVW)-based analyses. RESULTS: Neither TG (odds ratio [OR] = 1.149; 95% confidence interval [CI], 0.887-1.489; P = 0.293) nor HDL-C (OR = 0.864; 95% CI, 0.718-1.041; P = 0.124) had causal effects on LBD. However, a causal relationship was identified between LDL-C and LBD (OR = 1.343; 95% CI, 1.094-1.649; P = 0.005), which remained significant (OR = 1.237; 95% CI, 1.015-1.508; P = 0.035) following adjustment for HDL-C and TG in multivariable MR. CONCLUSIONS: Elevated serum LDL-C increases the risk of LBD, while HDL-C and TG have no significant causal effects on LBD.

Identification of metabolic pathways and key genes associated with atypical parkinsonism using a systems biology approach.

Atypical parkinsonism (AP) is a group of complex neurodegenerative disorders with marked clinical and pathophysiological heterogeneity. The use of systems biology tools may contribute to the characterization of hub-bottleneck genes, and the identification of its biological pathways to broaden the understanding of the bases of these disorders. A systematic search was performed on the DisGeNET database, which integrates data from expert curated repositories, GWAS catalogues, animal models and the scientific literature. The tools STRING 11.0 and Cytoscape 3.8.2 were used for analysis of protein-protein interaction (PPI) network. The PPI network topography analyses were performed using the CytoHubba 0.1 plugin for Cytoscape. The hub and bottleneck genes were inserted into 4 different sets on the InteractiveVenn. Additional functional enrichment analyses were performed to identify Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and gene ontology for a described set of genes. The systematic search in the DisGeNET database identified 485 genes involved with Atypical Parkinsonism. Superimposing these genes, we detected a total of 31 hub-bottleneck genes. Moreover, our functional enrichment analyses demonstrated the involvement of these hub-bottleneck genes in 3 major KEGG pathways. We identified 31 highly interconnected hub-bottleneck genes through a systems biology approach, which may play a key role in the pathogenesis of atypical parkinsonism. The functional enrichment analyses showed that these genes are involved in several biological processes and pathways, such as the glial cell development, glial cell activation and cognition, pathways were related to Alzheimer disease and Parkinson disease. As a hypothesis, we highlight as possible key genes for AP the MAPT (microtubule associated protein tau), APOE (apolipoprotein E), SNCA (synuclein alpha) and APP (amyloid beta precursor protein) genes.

Cognitive trajectories preluding the onset of different dementia entities: a descriptive longitudinal study using the NACC database.

OBJECTIVE: To describe the 10-year preclinical cognitive trajectories of older, non-demented individuals towards the onset of the four most prevalent types of dementia, i.e., Alzheimer's disease(AD), Lewy body(LBD), vascular(VD) and frontotemporal dementia(FTD). METHODS: Our analysis focused on data from older (≥ 60years) NACC (National Alzheimer's Coordinating Center) participants. Four distinct presymptomatic dementia groups (AD-LBD-VD-FTD) and a comparison group of cognitively unimpaired(CU) participants were formed. Comprehensive cognitive assessments involving verbal episodic memory, semantic verbal fluency, confrontation naming, mental processing speed - attention and executive function - cognitive flexibility were conducted at baseline and on an approximately yearly basis. Descriptive analyses (adjusted general linear models) were performed to determine and compare the yearly cognitive scores of each group throughout the follow-up. Exploratory analyses were conducted to estimate the rates of cognitive decline. RESULTS: There were 3343 participants who developed AD, 247 LBD, 108 FTD, 155 VD and 3398 composed the CU group. Participants with AD performed worse on episodic memory than those with VD and LBD for about 3 to 4 years prior to dementia onset (the FTD group documented an intermediate course). Presymptomatic verbal fluency and confrontation naming trajectories differentiated quite well between the FTD group and the remaining dementia entities. Participants with incident LBD and VD performed worse than those with AD on executive functions and mental processing speed-attention since about 5 years prior to the onset of dementia, and worse than those with FTD more proximally to the diagnosis of the disorder. CONCLUSIONS: Heterogeneous cognitive trajectories characterize the presymptomatic courses of the most prevalent dementia entities.

Markers for the detection of Lewy body disease versus Alzheimer's disease in mild cognitive impairment: a systematic review and meta-analysis.

BACKGROUND: Mild cognitive impairment (MCI) may evolve into dementia. Early recognition of possible evolution to Alzheimer's disease (AD) and dementia with Lewy Bodies (DLB) is of importance, but actual diagnostic criteria have some limitations. In this systematic review and meta-analysis, we aimed to find the most accurate markers that can discriminate patients with DLB versus AD, in MCI stage. METHODS: We searched several databases up to 17 August 2023 including studies comparing markers that may distinguish DLB-MCI from AD-MCI. We reported data regarding sensitivity, specificity, and the area under the curves (AUCs) with their 95% confidence intervals (CIs). RESULTS: Among 2219 articles initially screened, eight case-control studies and one cohort study were included for a total of 832 outpatients with MCI. The accuracy of cerebrospinal fluid (CSF) markers was the highest among the markers considered (AUC > 0.90 for the CSF markers), with the AUC of CSF Aß42/Aß40 of 0.94. The accuracy for clinical symptom scales was very good (AUC = 0.93), as evaluated in three studies. Although limited to one study, the accuracy of FDG-PET (cingulate island sign ratio) was very good (AUC = 0.95) in discriminating DLB from AD in MCI, while the accuracy of SPECT markers and EEG frequencies was variable. CONCLUSIONS: Few studies have assessed the accuracy of biomarkers and clinical tools to distinguish DLB from AD at the MCI stage. While results are promising for CSF markers, FDG-PET and clinical symptoms scales, more studies, particularly with a prospective design, are needed to evaluate their accuracy and clinical usefulness. CLINICAL TRIAL REGISTRATION: Prospero (CRD42023422600).

Soluble α-synuclein-antibody complexes activate the NLRP3 inflammasome in hiPSC-derived microglia.

Parkinson's disease is characterized by accumulation of α-synuclein (αSyn). Release of oligomeric/fibrillar αSyn from damaged neurons may potentiate neuronal death in part via microglial activation. Heretofore, it remained unknown if oligomeric/fibrillar αSyn could activate the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome in human microglia and whether anti-αSyn antibodies could prevent this effect. Here, we show that αSyn activates the NLRP3 inflammasome in human induced pluripotent stem cell (hiPSC)-derived microglia (hiMG) via dual stimulation involving Toll-like receptor 2 (TLR2) engagement and mitochondrial damage. In vitro, hiMG can be activated by mutant (A53T) αSyn secreted from hiPSC-derived A9-dopaminergic neurons. Surprisingly, αSyn-antibody complexes enhanced rather than suppressed inflammasome-mediated interleukin-1ß (IL-1ß) secretion, indicating these complexes are neuroinflammatory in a human context. A further increase in inflammation was observed with addition of oligomerized amyloid-ß peptide (Aß) and its cognate antibody. In vivo, engraftment of hiMG with αSyn in humanized mouse brain resulted in caspase-1 activation and neurotoxicity, which was exacerbated by αSyn antibody. These findings may have important implications for antibody therapies aimed at depleting misfolded/aggregated proteins from the human brain, as they may paradoxically trigger inflammation in human microglia.

Targeting Lewy body dementia with neflamapimod-rasagiline hybrids.

Lewy body dementia (LBD) represents the second most common neurodegenerative dementia but is a quite underexplored therapeutic area. Nepflamapimod (1) is a brain-penetrant selective inhibitor of the alpha isoform of the mitogen-activated serine/threonine protein kinase (MAPK) p38α, recently repurposed for LBD due to its remarkable antineuroinflammatory properties. Neuroprotective propargylamines are another class of molecules with a therapeutical potential against LBD. Herein, we sought to combine the antineuroinflammatory core of 1 and the neuroprotective propargylamine moiety into a single molecule. Particularly, we inserted a propargylamine moiety in position 4 of the 2,6-dichlorophenyl ring of 1, generating neflamapimod-propargylamine hybrids 3 and 4. These hybrids were evaluated using several cell models, aiming to recapitulate the complexity of LBD pathology through different molecular mechanisms. The N-methyl-N-propargyl derivative 4 showed a nanomolar p38α-MAPK inhibitory activity (IC50 = 98.7 nM), which is only 2.6-fold lower compared to that of the parent compound 1, while displaying no hepato- and neurotoxicity up to 25 µM concentration. It also retained a similar immunomodulatory profile against the N9 microglial cell line. Gratifyingly, at 5 µM concentration, 4 demonstrated a neuroprotective effect against dexamethasone-induced reactive oxygen species production in neuronal cells that was higher than that of 1.

Lewy body dementia: Overcoming barriers and identifying solutions.

Despite its high prevalence among dementias, Lewy body dementia (LBD) remains poorly understood with a limited, albeit growing, evidence base. The public-health burden that LBD imposes is worsened by overlapping pathologies, which contribute to misdiagnosis, and lack of treatments. For this report, we gathered and analyzed public-domain information on advocacy, funding, research outputs, and the therapeutic pipeline to identify gaps in each of these key elements. To further understand the current gaps, we also conducted interviews with leading experts in regulatory/governmental agencies, LBD advocacy, academic research, and biopharmaceutical research, as well as with funding sources. We identified wide gaps across the entire landscape, the most critical being in research. Many of the experts participated in a workshop to discuss the prioritization of research areas with a view to accelerating therapeutic development and improving patient care. This white paper outlines the opportunities for bridging the major LBD gaps and creates the framework for collaboration in that endeavor. HIGHLIGHTS: A group representing academia, government, industry, and consulting expertise was convened to discuss current progress in Dementia with Lewy Body care and research. Consideration of expert opinion,natural language processing of the literature as well as publicly available data bases, and Delphi inspired discussion led to a proposed consensus document of priorities for the field.

Apolipoprotein E Gene in α-Synucleinopathies: A Narrative Review.

In this narrative review, we delved into the intricate interplay between Apolipoprotein E (APOE) alleles (typically associated with Alzheimer's disease-AD) and alpha-synucleinopathies (aS-pathies), involving Parkinson's disease (PD), Parkinson's disease dementia (PDD), dementia with Lewy bodies (DLB), and multiple-system atrophy (MSA). First, in-vitro, animal, and human-based data on the exacerbating effect of APOE4 on LB pathology were summarized. We found robust evidence that APOE4 carriage constitutes a risk factor for PDD-APOE2, and APOE3 may not alter the risk of developing PDD. We confirmed that APOE4 copies confer an increased hazard towards DLB, as well. Again APOE2 and APOE3 appear unrelated to the risk of conversion. Of note, in individuals with DLB APOE4, carriage appears to be intermediately prevalent between AD and PDD-PD (AD > DLB > PDD > PD). Less consistency existed when it came to PD; APOE-PD associations tended to be markedly modified by ethnicity. Finally, we failed to establish an association between the APOE gene and MSA. Phenotypic associations (age of disease onset, survival, cognitive-neuropsychiatric- motor-, and sleep-related manifestations) between APOE alleles, and each of the aforementioned conditions were also outlined. Finally, a synopsis of literature gaps was provided followed by suggestions for future research.

Exploring the Regulatory Landscape of Dementia: Insights from Non-Coding RNAs.

Dementia, a multifaceted neurological syndrome characterized by cognitive decline, poses significant challenges to daily functioning. The main causes of dementia, including Alzheimer's disease (AD), frontotemporal dementia (FTD), Lewy body dementia (LBD), and vascular dementia (VD), have different symptoms and etiologies. Genetic regulators, specifically non-coding RNAs (ncRNAs) such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are known to play important roles in dementia pathogenesis. MiRNAs, small non-coding RNAs, regulate gene expression by binding to the 3' untranslated regions of target messenger RNAs (mRNAs), while lncRNAs and circRNAs act as molecular sponges for miRNAs, thereby regulating gene expression. The emerging concept of competing endogenous RNA (ceRNA) interactions, involving lncRNAs and circRNAs as competitors for miRNA binding, has gained attention as potential biomarkers and therapeutic targets in dementia-related disorders. This review explores the regulatory roles of ncRNAs, particularly miRNAs, and the intricate dynamics of ceRNA interactions, providing insights into dementia pathogenesis and potential therapeutic avenues.

Donepezil for dementia with Lewy bodies: meta-analysis of multicentre, randomised, double-blind, placebo-controlled phase II, III, and, IV studies.

BACKGROUND: Current evidence for the management of symptoms associated with dementia with Lewy bodies (DLB) using donepezil is limited. We conducted a meta-analysis of three randomised controlled trials of donepezil in patients with DLB to investigate the overall efficacy of donepezil on Mini-Mental State Examination (MMSE), Neuropsychiatric Inventory (NPI), and Clinician's Interview-Based Impression of Change-plus Caregiver Input (CIBIC-plus). METHODS: A meta-analysis was performed using the data of 312 patients administered placebo or 10 mg donepezil. Overall mean score differences for MMSE, NPI-2, and NPI-10 from baseline to week 12 and their 95% confidence intervals (CI) were estimated. For CIBIC-plus, which was transformed from a seven-point grade to a dichotomous outcome (improvements/no improvements), odds ratio (OR) and its 95% CI were estimated. Random-effects models were used, and heterogeneity was evaluated using the Cochrane's Q test and I2 statistic. RESULTS: Heterogeneity was suspected for NPI-2 (P < 0.05; I2 = 87.2%) and NPI-10 (P < 0.05; I2 = 67.7%) while it was not suspected for MMSE (P = 0.23; I2 = 32.4%) and CIBIC-plus (P = 0.26; I2 = 19.8%). The overall mean MMSE score difference (mean difference: 1.50; 95% CI, 0.67-2.34) and the overall odds of improving CIBIC-plus (OR: 2.20; 95% CI, 1.13-4.26) from baseline to week 12 were higher in the donepezil group than in the placebo group. CONCLUSION: Results of our meta-analysis indicated overall efficacy of donepezil on cognitive impairment and global clinical status in patients with DLB.

Efficacy and safety of donepezil in patients with dementia with Lewy bodies: results from a 12-week multicentre, randomised, double-blind, and placebo-controlled phase IV study.

BACKGROUND: Donepezil has been approved in Japan for the treatment of dementia with Lewy bodies (DLB) based on clinical trials showing its beneficial effects on cognitive impairment. This phase IV study evaluated the efficacy of donepezil by focusing on global clinical status during a 12-week double-blind phase. METHODS: Patients with probable DLB were randomly assigned to the placebo (n = 79) or 10 mg donepezil (n = 81) groups. The primary endpoint was changes in global clinical status, assessed using the Clinician's Interview-Based Impression of Change plus Caregiver Input (CIBIC-plus). We also assessed four CIBIC-plus domains (general condition, cognitive function, behaviour, and activities of daily living) and changes in cognitive impairment and behavioural and neuropsychiatric symptoms measured using the Mini-Mental State Examination (MMSE) and the Neuropsychiatric Inventory (NPI), respectively. RESULTS: Although donepezil's superiority was not shown in the global clinical status, a significant favourable effect was detected in the cognitive domain (P = 0.006). MMSE scores improved in the donepezil group after adjustments in post hoc analysis (MMSE mean difference, 1.4 (95% confidence interval (CI), 0.42-2.30), P = 0.004). Improvements in NPIs were similar between the groups (NPI-2: -0.2 (95% CI, -1.48 to 1.01), P = 0.710; NPI-10: 0.1 (95% CI, -3.28 to 3.55), P = 0.937). CONCLUSION: The results support the observation that the efficacy of 10 mg donepezil in improving cognitive function is clinically meaningful in DLB patients. The evaluation of global clinical status might be affected by mild to moderate DLB patients enrolled in this study. No new safety concerns were detected.

S-Nitrosylation of p62 Inhibits Autophagic Flux to Promote α-Synuclein Secretion and Spread in Parkinson's Disease and Lewy Body Dementia.

Dysregulation of autophagic pathways leads to accumulation of abnormal proteins and damaged organelles in many neurodegenerative disorders, including Parkinson's disease (PD) and Lewy body dementia (LBD). Autophagy-related dysfunction may also trigger secretion and spread of misfolded proteins, such as α-synuclein (α-syn), the major misfolded protein found in PD/LBD. However, the mechanism underlying these phenomena remains largely unknown. Here, we used cell-based models, including human induced pluripotent stem cell-derived neurons, CRISPR/Cas9 technology, and male transgenic PD/LBD mice, plus vetting in human postmortem brains (both male and female). We provide mechanistic insight into this pathologic pathway. We find that aberrant S-nitrosylation of the autophagic adaptor protein p62 causes inhibition of autophagic flux and intracellular buildup of misfolded proteins, with consequent secretion resulting in cell-to-cell spread. Thus, our data show that pathologic protein S-nitrosylation of p62 represents a critical factor not only for autophagic inhibition and demise of individual neurons, but also for α-syn release and spread of disease throughout the nervous system.SIGNIFICANCE STATEMENT In Parkinson's disease and Lewy body dementia, dysfunctional autophagy contributes to accumulation and spread of aggregated α-synuclein. Here, we provide evidence that protein S-nitrosylation of p62 inhibits autophagic flux, contributing to α-synuclein aggregation and spread.

Neural networks underlying visual illusions: An activation likelihood estimation meta-analysis.

Visual illusions have long been used to study visual perception and contextual integration. Neuroimaging studies employ illusions to identify the brain regions involved in visual perception and how they interact. We conducted an Activation Likelihood Estimation (ALE) meta-analysis and meta-analytic connectivity modeling on fMRI studies using static and motion illusions to reveal the neural signatures of illusory processing and to investigate the degree to which different areas are commonly recruited in perceptual inference. The resulting networks encompass ventral and dorsal regions, including the inferior and middle occipital cortices bilaterally in both types of illusions. The static and motion illusion networks selectively included the right posterior parietal cortex and the ventral premotor cortex respectively. Overall, these results describe a network of areas crucially involved in perceptual inference relying on feed-back and feed-forward interactions between areas of the ventral and dorsal visual pathways. The same network is proposed to be involved in hallucinogenic symptoms characteristic of schizophrenia and other disorders, with crucial implications in the use of illusions as biomarkers.

Elucidating distinct molecular signatures of Lewy body dementias.

Dementia with Lewy bodies and Parkinson's disease dementia are common neurodegenerative diseases that share similar neuropathological profiles and spectra of clinical symptoms but are primarily differentiated by the order in which symptoms manifest. The question of whether a distinct molecular pathological profile could distinguish these disorders is yet to be answered. However, in recent years, studies have begun to investigate genomic, epigenomic, transcriptomic and proteomic differences that may differentiate these disorders, providing novel insights in to disease etiology. In this review, we present an overview of the clinical and pathological hallmarks of Lewy body dementias before summarizing relevant research into genetic, epigenetic, transcriptional and protein signatures in these diseases, with a particular interest in those resolving "omic" level changes. We conclude by suggesting future research directions to address current gaps and questions present within the field.

Prognostic biomarkers in prodromal α-synucleinopathies: DAT binding and REM sleep without atonia.

BACKGROUND: Isolated rapid eye movement (REM) sleep behaviour disorder (iRBD) is a prodromal state of clinical α-synucleinopathies such as Parkinson's disease and Lewy body dementia. The lead-time until conversion is unknown. The most reliable marker of progression is reduced striatal dopamine transporter (DAT) binding, but low availability of imaging facilities limits general use. Our prospective observational study aimed to relate metrics of REM sleep without atonia (RWA)-a hallmark of RBD-to DAT-binding ratios in a large, homogeneous sample of patients with RBD to explore the utility of RWA as a marker of progression in prodromal α-synucleinopathies. METHODS: DAT single-photon emission CT (SPECT) and video polysomnography (vPSG) were performed in 221 consecutive patients with clinically suspected RBD. RESULTS: vPSG confirmed RBD in 176 patients (162 iRBD, 14 phenoconverted, 45 non-synucleinopathies). Specific DAT-binding ratios differed significantly between groups, but showed considerable overlap. Most RWA metrics correlated significantly with DAT-SPECT ratios (eg, Montreal tonic vs most-affected-region: r=-0.525; p<0.001). In patients taking serotonergic/noradrenergic antidepressants or dopaminergic substances or with recent alcohol abuse, correlations were weaker, suggesting a confounding influence, unlike other possible confounders such as beta-blocker use or comorbid sleep apnoea. CONCLUSIONS: In this large single-centre prospective observational study, we found evidence that DAT-binding ratios in patients with iRBD can be used to describe a continuum in the neurodegenerative process. Overlap with non-synucleinopathies and clinical α-synucleinopathies, however, precludes the use of DAT-binding ratios as a precise diagnostic marker. The parallel course of RWA metrics and DAT-binding ratios suggests in addition to existing data that RWA, part of the routine diagnostic workup in these patients, may represent a marker of progression. Based on our findings, we suggest ranges of RWA values to estimate whether patients are in an early, medium or advanced state within the prodromal phase of α-synucleinopathies, providing them with important information about time until possible conversion.