Gray matter alterations in Huntington's disease: A meta-analysis of VBM neuroimaging studies.

Increasing neuroimaging studies have attempted to identify biomarkers of Huntington's disease (HD) progression. Here, we conducted voxel-based meta-analyses of voxel-based morphometry (VBM) studies on HD to investigate the evolution of gray matter volume (GMV) alterations and explore the effects of genetic and clinical features on GMV changes. A systematic review was performed to identify the relevant studies. Meta-analyses of whole-brain VBM studies were performed to assess the regional GMV changes in all HD mutation carriers, in presymptomatic HD (pre-HD), and in symptomatic HD (sym-HD). A quantitative comparison was performed between pre-HD and sym-HD. Meta-regression analyses were used to explore the effects of genetic and clinical features on GMV changes. Twenty-eight studies were included, comparing a total of 1811 HD mutation carriers [including 1150 pre-HD and 560 sym-HD] and 969 healthy controls (HCs). Pre-HD showed decreased GMV in the bilateral caudate nuclei, putamen, insula, anterior cingulate/paracingulate gyri, middle temporal gyri, and left dorsolateral superior frontal gyrus compared with HCs. Compared with pre-HD, GMV decrease in sym-HD extended to the bilateral median cingulate/paracingulate gyri, Rolandic operculum and middle occipital gyri, left amygdala, and superior temporal gyrus. Meta-regression analyses found that age, mean lengths of CAG repeats, and disease burden were negatively associated with GMV atrophy of the bilateral caudate and right insula in all HD mutation carriers. This meta-analysis revealed the pattern of GMV changes from pre-HD to sym-HD, prompting the understanding of HD progression. The pattern of GMV changes may be biomarkers for disease progression in HD.

GWAS identifies DPP6 as risk gene of cognitive decline in Parkinson's disease.

BACKGROUND: Cognitive decline is among the most common non-motor symptoms in Parkinson's disease (PD), while its physiological mechanisms remain poorly understood. Genetic factors constituted a fundamental determinant in the heterogeneity of cognitive decline among PD patients. However, the underlying genetic background was still less studied. METHODS: To explore the genetic determinants contributing to cognitive decline in PD, we performed genome-wide survival analysis using a Cox proportional hazards model in a longitudinal cohort of 450 Chinese patients with PD, and further explored the functional effect of the target variant. Additionally, we built a clinical-genetic model by incorporating clinical characteristics and polygenic risk score (PRS) to predict cognitive decline in PD. RESULTS: The cohort was followed up for an average of 5.25 (SE=2.46) years, with 95 incidents of cognitive impairment. We identified significant association between locus rs75819919 (DPP6) and accelerated cognitive decline (P=8.63E-09, beta=1.74, SE=0.30). Dual-luciferase reporter assay suggested this locus might be involved in the regulation of DPP6 expression. Using dataset from the UK Biobank, we identified rs75819919 was associated with cognitive performance in the general population. Incorporation of PRS increased the model predictability, achieving an average AUC of 75.6% through 5-fold cross-validation in 1,000 iterations. CONCLUSIONS: These findings improve the current understanding of the genetic etiology of cognitive impairment in PD, and provide a novel target DPP6 to explore therapeutic options. Our results also demonstrate the potential to develop clinical-genetic model to identify patients susceptible to cognitive impairment and thus provide personalized clinical guidance.

Peripheral immunity involvement in the cognitive impairment of sporadic amyotrophic lateral sclerosis.

Background: Recent research has indicated the significance of immune activation in amyotrophic lateral sclerosis (ALS). However, the impact of peripheral immunity on cognitive impairment in sporadic ALS remains poorly characterized. Therefore, we aim to assess the relationship between peripheral immune parameters and cognitive impairment in patients with sporadic ALS. Methods: A case-control study involving 289 patients with sporadic ALS was conducted. All participants underwent cognitive assessment and measurements of blood immune parameters. The main outcomes included adjusted odds ratios (ORs) in multivariate logistic regression analysis and adjusted coefficients in a multivariate linear regression model. Sensitivity analysis was performed with stratification by the King's clinical stage. Results: Cognitive impairment was observed in 98 (33.9%) patients. Higher counts of leukocyte (OR, 0.53; 95% CI, 0.29 to 0.95; p = 0.03), neutrophil (OR, 0.48; 95% CI, 0.26 to 0.88; p = 0.02), and monocyte (OR, 0.33; 95% CI, 0.18 to 0.60; p < 0.001) were significantly associated with better cognitive preformence in sporadic ALS, particularly among patients in King's clinical stages 1 and 2. Conversely, a higher percentage of CD4+ T cells was linked to an increased risk of cognitive impairment (OR, 2.79; 95% CI, 1.52 to 5.09; p = 0.001), particularly evident in patients in King's clinical stage 3. Conclusion: These results highlight the involvement of peripheral immunity in the cognitive impairment of sporadic ALS and suggest dynamic and intricate roles that vary across disease stages. Elucidating the links between immunity and ALS sheds light on the pathophysiological mechanisms underlying this fatal neurodegenerative disorder and informs potential immunotherapeutic strategies.

Clinical and genetic characteristics of ALS patients with variants in genes regulating DNA methylation.

BACKGROUND: Aberrant DNA methylation alterations are implicated in amyotrophic lateral sclerosis (ALS). Nevertheless, the influence of genetic variants in genes regulating DNA methylation on ALS patients is not well understood. Therefore, we aim to provide a comprehensive variant profile of genes related to DNA methylation (DNMT1, DNMT3A, DNMT3B, DNMT3L) and demethylation (TET1, TET2, TET3, TDG) and to investigate the association of these variants with ALS. METHODS: Variants were screened in a cohort of 2240 ALS patients from Southwest China, using controls from the Genome Aggregation Database (n = 9976) and the China Metabolic Analytics Project (n = 10,588). The over-representation of rare variants and their association with ALS risk were evaluated using Fisher's exact test with Bonferroni correction at both allele and gene levels. Kaplan-Meier analysis and Cox regression analysis were employed to explore the relationship between variants and survival. RESULTS: A total of 210 variants meeting the criteria were identified. Gene-based burden analysis identified a significant increase in ALS risk associated with rare variants in the TET2 gene (OR = 1.95, 95% CI = 1.29-2.88, P = 0.001). Survival analysis demonstrated that patients carrying variants in demethylation-related genes had a higher risk of death compared to those with methylation-related gene variants (HR = 1.29, 95% CI = 1.03-1.86, P = 0.039). CONCLUSIONS: This study provides a genetic variant profile of genes involved in DNA methylation and demethylation regulation, along with the clinical characteristics of ALS patients carrying these variants. The findings offer genetic evidence implicating disrupted DNA methylation dynamics in ALS.

MMGPL: Multimodal Medical Data Analysis with Graph Prompt Learning.

Prompt learning has demonstrated impressive efficacy in the fine-tuning of multimodal large models to a wide range of downstream tasks. Nonetheless, applying existing prompt learning methods for the diagnosis of neurological disorder still suffers from two issues: (i) existing methods typically treat all patches equally, despite the fact that only a small number of patches in neuroimaging are relevant to the disease, and (ii) they ignore the structural information inherent in the brain connection network which is crucial for understanding and diagnosing neurological disorders. To tackle these issues, we introduce a novel prompt learning model by learning graph prompts during the fine-tuning process of multimodal models for diagnosing neurological disorders. Specifically, we first leverage GPT-4 to obtain relevant disease concepts and compute semantic similarity between these concepts and all patches. Secondly, we reduce the weight of irrelevant patches according to the semantic similarity between each patch and disease-related concepts. Moreover, we construct a graph among tokens based on these concepts and employ a graph convolutional network layer to extract the structural information of the graph, which is used to prompt the pre-trained multimodal models for diagnosing neurological disorders. Extensive experiments demonstrate that our method achieves superior performance for neurological disorder diagnosis compared with state-of-the-art methods and validated by clinicians.

Albumin and multiple sclerosis: a prospective study from UK Biobank.

Background: Multiple sclerosis (MS) is a chronic inflammatory disease affecting the central nervous system. While previous studies have indicated that albumin, the primary protein in human plasma, may exert influence on the inflammatory process and confer beneficial effects in neurodegenerative disorders, its role in the context of MS has been underexplored. Here, we aimed to explore the link between albumin and the risk of MS. Methods: Employing data from the UK Biobank, we investigated the association between baseline levels of serum and urine albumin and the risk of MS using Cox proportional hazards regression analysis. Results: A higher baseline level of serum albumin was associated with a lower risk of incident MS (HR=0.94, 95% CI: 0.91-0.98, P=7.66E-04). Subgroup analysis revealed a more pronounced effect in females, as well as participants with younger ages, less smoking and deficient levels of vitamin D. Conversely, no association was identified between baseline microalbuminuria level and risk of incident MS. Conclusion: Higher serum albumin level at baseline is linked to a reduced risk of MS. These results contribute to an enhanced understanding of albumin's role in MS, propose the potential use of albumin as a biomarker for MS, and have implications for the design of therapeutic interventions targeting albumin in clinical trials.

Amyotrophic lateral sclerosis patients with various gene mutations show diverse motor phenotypes and survival in China.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterised by progressive degeneration of motor neurons. Genetic factors have a substantial impact on ALS. Therefore, this study aimed to explore the correlation between genotype (SOD1, TARDBP, FUS, C9orf72) and phenotype in ALS. METHODS: Genetic analysis was performed on 2038 patients with ALS, among which 1696 patients with sporadic ALS (SALS) as controls for genotype-phenotype analysis, and 1602 SALS as controls for survival analysis. Logistic regression and Cox proportional hazards models were used for statistical analysis. RESULTS: A total of 172 patients with ALS with the gene mutations were included in the statistical analysis (SOD1, n=65; FUS, n=43; TARDBP, n=27; C9orf72, n=37). SOD1 mutations were more frequent in flail leg phenotype (OR 7.317, p=0.001) and less in bulbar phenotype (OR 0.222, p=0.038). C9orf72 expansions exhibited higher frequency in bulbar phenotype (OR 2.770, p=0.008). SOD1 and FUS mutations were significantly associated with earlier age of onset (HR 2.039, p<0.001; HR 1.762, p=0.001). The patients with SOD1 mutations, C9orf72 expansions and those carrying pathogenic FUS mutations had significantly increased death risk (HR 2.217, p<0.001; HR 1.694, p=0.008; HR 1.652, p=0.036). The increased risk of death in ALS with C9orf72 expansions was significant in females (HR 2.419, p=0.014) but not in males (HR 1.442, p=0.128). CONCLUSION: Our study revealed distinct motor phenotypic tendencies in patients with ALS with different genotypes, indicating variations in the vulnerability of motor neurons during the disease's progression. Furthermore, we made novel discoveries regarding survival of different gene mutations, warranting further investigation.

A novel mutation in SORD gene associated with distal hereditary motor neuropathies.

BACKGROUND: Distal hereditary motor neuropathy (dHMN) is a heterogeneous group of hereditary diseases caused by the gradual degeneration of the lower motor neuron. More than 30 genes associated with dHMN have been reported, while 70-80% of those with the condition are still unable to receive a genetic diagnosis. METHODS: A 26-year-old man experiencing gradual weakness in his lower limbs was referred to our hospital, and data on clinical features, laboratory tests, and electrophysiological tests were collected. To identify the disease-causing mutation, we conducted whole exome sequencing (WES) and then validated it through Sanger sequencing for the proband and his parents. Silico analysis was performed to predict the pathogenesis of the identified mutations. A literature review of all reported mutations of the related gene for the disease was performed. RESULTS: The patient presented with dHMN phenotype harboring a novel homozygous variant c.361G > C (p.Ala121Pro) in SORD, inherited from his parents, respectively. A121 is a highly conserved site and the mutation was categorized as "likely pathogenic" according to the criteria and guidelines of the American College of Medical Genetics and Genomics (ACMG). A total of 13 published articles including 101 patients reported 18 SORD variants. Almost all described cases have the homozygous deletion variant c.757delG (p.A253Qfs*27) or compound heterozygous state of a combination of c.757delG (p.A253Qfs*27) with another variant. The variant c.361G > C (p.Ala121Pro) detected in our patient was the second homozygous variant in SORD-associated hereditary neuropathy. CONCLUSION: One novel homozygous variant c.361G > C (p.Ala121Pro) in SORD was identified in a Chinese patient with dHMN phenotype, which expands the mutation spectrum of SORD-associated hereditary neuropathy and underscores the significance of screening for SORD variants in patients with undiagnosed hereditary neuropathy patients.

Correlation analysis of peripheral platelet markers and disease phenotypes in Alzheimer's disease.

INTRODUCTION: Platelets serve as the primary peripheral reservoir of amyloid beta (Aß). However, there is limited research on platelet markers in routine blood examinations, particularly with regard to the large platelet ratio (P-LCR) in Alzheimer's disease (AD). METHODS: This study included 512 AD patients and 205 healthy controls (HCs). Platelet markers and apolipoprotein E (APOE) 4 status were assessed in all participants. RESULTS: The study revealed that P-LCR was significantly elevated in AD patients compared to HCs. In AD patients carrying APOE4, P-LCR significantly negatively correlated with Montreal Cognitive Assessment scores. There was an observed increasing trend in the rate of change in P-LCR with disease progression. Binary logistic regression analysis indicated that P-LCR may constitute a risk factor for AD, after adjusting for age, sex, APOE4, and body mass index. DISCUSSION: P-LCR is associated with disease severity in AD patients carrying APOE4. P-LCR may be a promising marker to reflect platelet activity in AD patients. HIGHLIGHTS: P-LCR significantly negatively correlated with MoCA scores in AD patients with APOE4. The rate of change in P-LCR showed an increasing trend with disease progression. P-LCR may be a risk factor for AD.

The impact of maternal smoking during pregnancy and the age of smoking initiation on incident dementia: A prospective cohort study.

INTRODUCTION: The impact of early-life tobacco exposure on dementia has remained unknown. METHODS: Using the UK Biobank, the associations of maternal smoking during pregnancy (MSDP) and age of smoking initiation (ASI) with the onset time of all-cause dementia were estimated with accelerated failure time models. The effects of MSDP and ASI on brain structure and their genetic correlation to Alzheimer's disease (AD) were analyzed. A Mendelian randomization (MR) analysis was conducted. RESULTS: The time ratios for smokers starting in childhood, adolescence, and adulthood (vs never smokers) were 0.87 (0.76 to 0.99), 0.92 (0.88 to 0.96), and 0.95 (0.89 to 1.01). MSDP and smoking in adolescence altered many brain regions, including the hippocampus. In genetic analysis, MSDP was genetically and causally linked to AD, and a younger ASI was genetically correlated to a higher AD risk. DISCUSSION: Early-life smoking accelerated dementia onset and was genetically correlated to AD. MSDP demonstrated genetic and causal linkage to AD risks. HIGHLIGHTS: Unlike the commonly used Cox proportional hazards model, this article uses a parametric survival analysis method - the accelerated failure model - to explore the relationship between exposure to onset time. It can be used as an alternative method when the proportional hazards assumption is not met. Genetic analyses including genetic correlation study and MR analysis and brain structure analyses were conducted to support our findings and explore the potential mechanisms. The study reveals the relationship between different smoking initiation periods and the onset time of dementia and shows that earlier smoking exposure has a more significant impact on dementia. It emphasizes the importance of preventing early smoking. In the future, more research focusing on the relationship between early exposure and dementia is called for to provide more detailed prevention measures for dementia that cover all age groups.

Calcium channel blockers and Parkinson's disease: a systematic review and meta-analysis.

Background: The calcium channel has been considered to have great potential as a drug target for neuroprotective therapy in Parkinson's disease (PD), but previous studies yielded inconsistent results. Objectives: This study aimed to conduct a systematic review and meta-analysis to assess the relationship between using calcium channel blockers (CCBs) and the risk and progression of PD. Data sources and methods: The terms such as 'Parkinson's disease', 'PD', 'calcium channel blockers', and 'CCB' were used to search the literature published before 1 May 2023 in English databases, including PubMed, Embase, and Cochrane Library, for studies on CCB and PD. Data analysis was performed using Review Manager 5.3 software. Results: A total of 190 works of literature were preliminarily retrieved, and 177 works of literature were excluded by eliminating duplicates, reading abstracts, and reading full texts. A total of nine studies were finally included in the meta-analysis of the CCB and the risk of PD, and five studies were included in the systematic review of the CCB and the progression of PD. A total of 2,961,695 participants were included in the meta-analysis. The random-effects model was used for analysis due to significant heterogeneity. The main results of the meta-analysis showed that the use of CCB could reduce the risk of PD (relative risk 0.78, 95% confidence interval 0.62-0.99). Conclusion: CCB use was associated with a significantly reduced risk of PD. Whether CCB use has a disease-modifying effect on PD needs further study. Registration: PROSPERO: CRD42024508242.

Associations of cerebrospinal fluid profiles with severity and mortality risk of amyotrophic lateral sclerosis.

Background: The relationship between routine cerebrospinal fluid (CSF) testing and the disease phenotype of amyotrophic lateral sclerosis (ALS) is unclear, and there are some contradictions in current studies. Methods: This study aimed to analyze the relationship between CSF profiles and disease phenotype in ALS patients. We collected 870 ALS patients and 96 control subjects admitted to West China Hospital of Sichuan University. CSF microprotein, albumin, IgG, index of IgG (IgGindex), albumin quotient (QALB), and serum IgG were examined. Results: In ALS patients, CSF IgG, and QALB were significantly increased, while CSF IgGindex was decreased, compared with control subjects. Approximately one-third of ALS patients had higher CSF IgG levels. The multiple linear regression analysis identified that CSF IgGindex was weakly negatively associated with ALS functional rating scale revised (ALSFRS-R) scores (ß = -0.062, p = 0.041). This significance was found in male ALS but not in female ALS. The Cox survival analyses found that upregulated CSF IgG was significantly associated with the increased mortality risk in ALS [HR = 1.219 (1.010-1.470), p = 0.039]. Conclusion: In the current study, the higher CFS IgG was associated with increased mortality risk of ALS. CSF IgGindex may be associated with the severity of ALS. These findings may be sex-specific.

Alzheimer's disease and oral manifestations: a bi-directional Mendelian randomization study.

Background: Epidemiological studies have provided evidence suggesting an association between Alzheimer's disease (AD) and various oral manifestations. However, conflicting conclusions have been drawn, and whether a causal association truly exists remains unclear. Methods: In order to investigate the potential causal association between AD and prevalent oral diseases, we conducted a bi-directional two-sample Mendelian randomization analysis based on summary statistics from genome-wide association studies of AD (N = 63,926), as well as mouth ulcer (N = 461,103), oral cavity cancer (N = 4,151), and periodontal disease (N = 527,652). Results: We identified that one standard increase in the risk of AD was causally associated with a reduced risk of oral cavity cancer (OR = 0.76, 95% CI: 0.63-0.92, p = 3.73 × 10-3). In the opposite direction, oral conditions were not causally associated with risk of AD. Conclusion: The present findings contributed to a better understanding of the correlation between AD and oral conditions, specifically oral cavity cancer. These results also identified new avenues for exploring the underlying mechanisms of oral cavity cancer.

Latest advances on new promising molecular-based therapeutic approaches for Huntington's disease.

Huntington's disease (HD) is a devastating, autosomal-dominant inherited, neurodegenerative disorder characterized by progressive motor deficits, cognitive impairments, and neuropsychiatric symptoms. It is caused by excessive cytosine-adenine-guanine (CAG) trinucleotide repeats within the huntingtin gene (HTT). Presently, therapeutic interventions capable of altering the trajectory of HD are lacking, while medications for abnormal movement and psychiatric symptoms are limited. Numerous pre-clinical and clinical studies have been conducted and are currently underway to test the efficacy of therapeutic approaches targeting some of these mechanisms with varying degrees of success. In this review, we update the latest advances on new promising molecular-based therapeutic strategies for this disorder, including DNA-targeting techniques such as zinc-finger proteins, transcription activator-like effector nucleases, and CRISPR/Cas9; post-transcriptional huntingtin-lowering approaches such as RNAi, antisense oligonucleotides, and small-molecule splicing modulators; and novel methods to clear the mHTT protein, such as proteolysis-targeting chimeras. We mainly focus on the ongoing clinical trials and the latest pre-clinical studies to explore the progress of emerging potential HD therapeutics.

Predictors for survival in patients with Alzheimer's disease: a large comprehensive meta-analysis.

The prevalence of Alzheimer's disease (AD) is increasing as the population ages, and patients with AD have a poor prognosis. However, knowledge on factors for predicting the survival of AD remains sparse. Here, we aimed to systematically explore predictors of AD survival. We searched the PubMed, Embase and Cochrane databases for relevant literature from inception to December 2022. Cohort and case-control studies were selected, and multivariable adjusted relative risks (RRs) were pooled by random-effects models. A total of 40,784 reports were identified, among which 64 studies involving 297,279 AD patients were included in the meta-analysis after filtering based on predetermined criteria. Four aspects, including demographic features (n = 7), clinical features or comorbidities (n = 13), rating scales (n = 3) and biomarkers (n = 3), were explored and 26 probable prognostic factors were finally investigated for AD survival. We observed that AD patients who had hyperlipidaemia (RR: 0.69) were at a lower risk of death. In contrast, male sex (RR: 1.53), movement disorders (including extrapyramidal signs) (RR: 1.60) and cancer (RR: 2.07) were detrimental to AD patient survival. However, our results did not support the involvement of education, hypertension, APOE genotype, Aß42 and t-tau in AD survival. Our study comprehensively summarized risk factors affecting survival in patients with AD, provided a better understanding on the role of different factors in the survival of AD from four dimensions, and paved the way for further research.

The characteristic and prognostic role of blood inflammatory markers in patients with Huntington's disease from China.

Objectives: This study aims to elucidate the role of peripheral inflammation in Huntington's disease (HD) by examining the correlation of peripheral inflammatory markers with clinical manifestations and disease prognosis. Methods: This investigation involved 92 HD patients and 92 matched healthy controls (HCs). We quantified various peripheral inflammatory markers and calculated their derived metrics including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and systemic immune-inflammation index (SII). Clinical assessments spanning cognitive, motor, and disease severity were administered. Comparative analysis of inflammatory markers and clinical correlations between HD and controls was performed. Kaplan-Meier survival analysis and Cox regression model were used to assess the effect of inflammatory markers on survival. Results: The study revealed that HD patients had significantly reduced lymphocyte counts, and LMR. Conversely, NLR, PLR, and SII were elevated compared to HCs. Lymphocyte levels inversely correlated with the age of onset and monocyte levels inversely correlated with the UHDRS-total functional capacity (TFC) scores. After adjusting for age, sex, and CAG repeat length, lymphocyte count, NLR, PLR, and SII were significantly correlated with the progression rate of TFC scores. Elevated levels of white blood cells and monocytes were associated with an increased risk of disability and mortality in the HD cohort. Conclusion: Our findings indicate that HD patients display a distinct peripheral inflammatory profile with increased NLR, PLR, and SII levels compared to HCs. The peripheral inflammation appears to be linked with accelerated disease progression and decreased survival in HD.

Cognitive impairment, neuroimaging abnormalities, and their correlations in myotonic dystrophy: a comprehensive review.

Myotonic dystrophy (DM) encompasses a spectrum of neuromuscular diseases characterized by myotonia, muscle weakness, and wasting. Recent research has led to the recognition of DM as a neurological disorder. Cognitive impairment is a central nervous system condition that has been observed in various forms of DM. Neuroimaging studies have increasingly linked DM to alterations in white matter (WM) integrity and highlighted the relationship between cognitive impairment and abnormalities in WM structure. This review aims to summarize investigations into cognitive impairment and brain abnormalities in individuals with DM and to elucidate the correlation between these factors and the potential underlying mechanisms contributing to these abnormalities.

Sleep characteristics and risk of Alzheimer's disease: a systematic review and meta-analysis of longitudinal studies.

BACKGROUND: Alzheimer's disease (AD) is on the rise in our aging society, making it crucial to identify additional risk factors to mitigate its increasing incidence. This systematic review and meta-analysis aimed to provide updated evidence regarding the association between sleep and AD. METHODS: We conducted a comprehensive search of MEDLINE, EMBASE, and Web of Science databases from inception to July 2023 to identify longitudinal studies. Adjusted relative risks were pooled for each sleep characteristic, and a dose-response analysis was performed specifically for sleep duration. RESULTS: A total of 15,278 records were initially retrieved, and after screening, 35 records were ultimately included in the final analysis. The results showed that insomnia (RR, 1.43; 95%CI, 1.17-1.74), sleep-disordered breathing (RR, 1.22; 95%CI, 1.07-1.39), as well as other sleep problems, including sleep fragmentation and sleep-related movement disorders, were associated with a higher risk of developing AD, while daytime napping or excessive daytime sleepiness (RR, 1.18; 95%CI, 1.00-1.40) only exhibited a trend toward a higher risk of AD development. Furthermore, our analysis revealed a significant association between self-reported sleep problems (RR, 1.34; 95%CI, 1.26-1.42) and the incidence of AD, whereas this association was not observed with sleep problems detected by objective measurements (RR, 1.14; 95%CI, 0.99-1.31). Moreover, both quite short sleep duration (< 4 h) and long duration (> 8 h) were identified as potential risk factors for AD. CONCLUSIONS: Our study found the association between various types of sleep problems and an increased risk of AD development. However, these findings should be further validated through additional objective device-based assessments. Additional investigation is required to establish a definitive causal connection between sleep problems and AD.

Plasma GFAP as a prognostic biomarker of motor subtype in early Parkinson's disease.

Parkinson's disease (PD) is a heterogeneous movement disorder with different motor subtypes including tremor dominant (TD), indeterminate and postural instability, and gait disturbance (PIGD) motor subtypes. Plasma glial fibrillary acidic protein (GFAP) was elevated in PD patients and may be regarded as a biomarker for motor and cognitive progression. Here we explore if there was an association between plasma GFAP and different motor subtypes and whether baseline plasma GFAP level can predict motor subtype conversion. Patients with PD classified as TD, PIGD or indeterminate subtypes underwent neurological evaluation at baseline and 2 years follow-up. Plasma GFAP in PD patients and controls were measured using an ultrasensitive single molecule array. The study enrolled 184 PD patients and 95 control subjects. Plasma GFAP levels were significantly higher in the PIGD group compared to the TD group at 2-year follow-up. Finally, 45% of TD patients at baseline had a subtype shift and 85% of PIGD patients at baseline remained as PIGD subtypes at 2 years follow-up. Baseline plasma GFAP levels were significantly higher in TD patients converted to PIGD than non-converters in the baseline TD group. Higher baseline plasma GFAP levels were significantly associated with the TD motor subtype conversion (OR = 1.283, P = 0.033) and lower baseline plasma GFAP levels in PIGD patients were likely to shift to TD and indeterminate subtype (OR = 0.551, P = 0.021) after adjusting for confounders. Plasma GFAP may serve as a clinical utility biomarker in differentiating motor subtypes and predicting baseline motor subtypes conversion in PD patients.