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Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases. The typical symptomatology of PD includes motor symptoms; however, a range of nonmotor symptoms, such as intestinal issues, usually occur before the motor symptoms. Various microorganisms inhabiting the gastrointestinal tract can profoundly influence the physiopathology of the central nervous system through neurological, endocrine, and immune system pathways involved in the microbiota–gut–brain axis. In addition, extensive evidence suggests that the gut microbiota is strongly associated with PD. This review summarizes the latest findings on microbial changes in PD and their clinical relevance, describes the underlying mechanisms through which intestinal bacteria may mediate PD, and discusses the correlations between gut microbes and anti-PD drugs. In addition, this review outlines the status of research on microbial therapies for PD and the future directions of PD–gut microbiota research. [ABSTRACT FROM AUTHOR]

In principle, induced pluripotent stem cells (iPSCs) are generated from somatic cells by reprogramming and gaining the capacity to self-renew indefinitely as well as the ability to differentiate into cells of different lineages. Human iPSCs have absolute advantages over human embryonic stem cells (ESCs) and animal models in disease modeling, drug screening, and cell replacement therapy. Since Takahashi and Yamanaka first described in 2007 that iPSCs can be generated from human adult somatic cells by retroviral transduction of the four transcription factors, Oct3/4, Sox2, Klf4, and c-Myc, disease specific iPSC lines have sprung up worldwide like bamboo shoots after a spring rain, making iPSC one of the hottest and fastest moving topics in modern science. The craze for iPSCs has spread throughout main branches of clinical medicine, covering neurology, hematology, cardiology, endocrinology, hepatology, ophthalmology, and so on. Here in this paper, we will focus on the clinical application of human iPSCs in disease modeling, drug screening, and cell replacement therapy for neurological diseases. [ABSTRACT FROM AUTHOR]

In principle, induced pluripotent stem cells (iPSCs) are generated from somatic cells by reprogramming and gaining the capacity to self-renew indefinitely as well as the ability to differentiate into cells of different lineages. Human iPSCs have absolute advantages over human embryonic stem cells (ESCs) and animal models in disease modeling, drug screening, and cell replacement therapy. Since Takahashi and Yamanaka first described in 2007 that iPSCs can be generated from human adult somatic cells by retroviral transduction of the four transcription factors, Oct3/4, Sox2, Klf4, and c-Myc, disease specific iPSC lines have sprung up worldwide like bamboo shoots after a spring rain, making iPSC one of the hottest and fastest moving topics in modern science. The craze for iPSCs has spread throughout main branches of clinical medicine, covering neurology, hematology, cardiology, endocrinology, hepatology, ophthalmology, and so on. Here in this paper, we will focus on the clinical application of human iPSCs in disease modeling, drug screening, and cell replacement therapy for neurological diseases. [ABSTRACT FROM AUTHOR]

Highlights: [•] BAG2 colocalizes with PINK1 and R492X PINK1 mutation in vivo. [•] BAG2 binds with PINK1 directly and stabilizes PINK1 by decreasing its ubiquitination. [•] BAG2 also binds with R492X PINK1 mutation, directly and more tightly. [•] BAG2 stabilizes R492X PINK1 mutation by decreasing its ubiquitination more obviously. [Copyright &y& Elsevier]

Optogenetic technology, also known as optogenetics, is a novel multidisciplinary field in biotechnology that integrates genetic engineering, electrophysiology, and optical and electronic engineering. This recently developed technology has evolved rapidly and generated considerable excitement in neuroscience research. This technology successfully solves the severe problem of achieving both high temporal and spatial precision within intact neural tissues of animals that electrical stimulation and pharmacological methods cannot achieve. It allows neurons to express light-sensitive genes that enable the identification, dissection, and manipulation of specific neural populations and their connections in the tissues and organs of awake animals with unprecedented spatial and temporal precision. Light-sensitive genes chiefly including the genetically targeted light-gated channels channelrhodopsin-2 (ChR2) and halorhodopsin (NpHR) cause intracellular ion flow during optical illumination. Subsequently, the neurons undergo a series of changes resulting from membrane depolarization or hyperpolarization. To date, there are many published research articles and reviews that describe this new technology; however, few of the reports concern its application to neuropsychiatric diseases. In this review, we summarize the most recent optogenetic research in these diseases, including Parkinson's disease (PD), epilepsy, schizophrenia, anxiety, fear, reward behaviors, and sleep disorders. We propose that novel optogenetics technology creates excellent opportunities for innovative treatment strategies of neuropsychiatric diseases. [ABSTRACT FROM AUTHOR]

Vitamin D and vitamin D receptor (VDR) have been postulated as environmental and genetic factors in neurodegenerative disorders including multiple sclerosis, Alzheimer disease, and recently Parkinson disease (PD). The purpose of this study is to explore the potential correlation between single nucleotide polymorphisms of the VDR gene (VDR) rs4334089 and rs731236 and PD. A total of 483 patients with PD and 498 age- and sex-matched controls were involved in this study. Genotypes were determined by using polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing. There were no significant differences in the genotype and allele frequencies of VDR rs4334089 and rs731236 polymorphisms between the group of patients with PD and the control group in a Chinese Han population (for VDR rs4334089: OR 1.02, 95% CI: 0.85-1.23; for VDR rs731236: OR 1.13, 95% CI: 0.75-1.71). Similarly, there were still no differences when stratifying by age or by gender. These findings suggest that VDR gene is not a susceptibility gene for PD in our population. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is the second most common neurodegenerative disorder. The presence of Lewy bodies is a major pathological change of PD. α-synuclein is the main component of Lewy bodies and is encoded by the SNCA gene. Mutations in the SNCA gene mainly result in rare familial forms of PD, while genetic variability in the SNCA gene modulates susceptibility to sporadic PD. Recent studies have suggested that levels of α-synuclein in extracellular biological fluid are associated with PD and implicated α-synuclein as a potential biomarker for PD diagnosis and severity. We studied serum α-synuclein concentration and two polymorphic variants of SNCA (Rep1 and rs11931074) in 110 sporadic PD patients and 136 controls. We further explored the influence of the two polymorphisms on the expression levels of serum α-synuclein. Soluble α-synuclein was detected in serum in all subjects, with no statistically significant difference between PD patients and controls ( p = 0.611). Different Rep1 alleles and genotypes did not influence the expression of serum α-synuclein. The frequency of allele T of rs11931074 was significantly elevated in PD patients ( p = 0.041), and was correlated with decreased serum α-synuclein in both dominant ( p = 0.011) and additive ( p = 0.008) models of association. [ABSTRACT FROM AUTHOR]

Abstract: Ataxia telangiectasia (A–T) is an autosomal recessive disorder characterized by cerebellar ataxia, telangiectasia, immunodeficiency, elevated α-fetoprotein level, chromosomal instability, predisposition to cancer, and radiation sensitivity. Although a lot of mutations in the ATM gene have been described, there is still no report about ATM mutations in Chinese population. Using a molecular approach, we screened for ATM mutations in two patients from two unrelated Chinese families. 100 normal controls were analyzed to exclude possibility of polymorphism. Two novel mutations in the ATM gene were identified. The first one is a novel, homozygous, 1346G>C (Gly449Ala) missense mutation. The second one is a compound heterozygous mutation, which consists of a novel, 610G>T (Gly204Stop) nonsense mutation, combined with a previously reported, 6679C>T (Arg2227Cys) missense mutation. The transversions 1346G>C (Gly449Ala) and 610G>T (Gly204Stop) are not localized either in the conserved PI-3 kinase domain or in the other domains of the ATM protein. The phenotypic features were characterized by progressive cerebellar ataxia, ocular telangiectasia, elevated α-fetoprotein level, immunodeficiency (agammaglo–bulinemia and T-cell defect), and rearrangements of chromosomes 7 and 14; brain MRI showed cerebellar atrophy, brain SPECT showed cerebellar regional cerebral blood flow (rCBF) hypoperfusion. To our knowledge, this is the first report of ATM mutations in Mainland China, in which the transversions 1346G>C (Gly449Ala) and 610G>T (Gly204Stop) are two novel, disease-causing mutations. [Copyright &y& Elsevier]

Abstract: The hereditary spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders. The genes causing 11 of these diseases have been identified. To date, there is no report of SCA type 6 (SCA6) in Mainland Chinese. Using a molecular approach, we investigated SCA6 as well as other SCA subtype in 120 Mainland Chinese families with dominantly inherited ataxias and in 60 Mainland Chinese patients with sporadic ataxias. Clinical and molecular features of SCA6 were further characterized in 13 patients from 4 families. We found that SCA3/MJD was the most common type of autosomal dominant SCA in Mainland Chinese, accounting for 83 patients from 59 families (49.2%), followed by SCA2 (8 [6.7%]), SCA1 (7 [5.8%]), SCA6 (4 [3.3%]), SCA7 (1 [0.8%]), SCA8 (0%), SCA10 (0%), SCA12 (1 [0.8%]), SCA14 (0%), SCA17 (0%) and DRPLA (0%). The genes responsible for 40 (33.3%) of dominantly inherited SCA families remain to be determined. Among the 60 patients with sporadic ataxias in the present series, 3 (5.0%) were found to harbor SCA3 mutations, whereas none were found to harbor SCA6 mutations. In the 4 families with SCA6, we found significant anticipation in the absence of genetic instability on transmission. This is the first report of geographic cluster of families with SCA6 subtype in Mainland China. [Copyright &y& Elsevier]

Benign familial neonatal convulsions (BFNC) are a rare autosomal dominant inherited epilepsy syndrome. Two voltage-gated potassium channel genes, KCNQ2 on chromosome 20q13.3 and KCNQ3 on chromosome 8q24, have been identified as the genes responsible for benign familial neonatal convulsions. By linkage analysis and mutation analysis of KCNQ2 gene, we found a novel frameshift mutation of KCNQ2 gene, 1931delG , in a large Chinese family with benign familial neonatal convulsions. This mutation is located in the C-terminus of KCNQ2, in codon 644 predicting the replacement of the last 201 amino acids with a stretch of 257 amino acids showing a completely different sequence. An unusual clinical feature of this family is that the seizures of every patient did not remit until 12 to 18 months. This is the first report of KCNQ2 gene mutation in China. [Copyright &y& Elsevier]

Objective Methods Results Interpretation Transcranial sonography (TCS) is a noninvasive neuroimaging technique, visualizing deep brain structures and the ventricular system. Although widely employed in diagnosing various movement disorders, such as Parkinson's disease and dystonia, by detecting disease‐specific abnormalities, the specific characteristics of the TCS in cerebellar ataxia remain inconclusive. We aimed to assess the potential value of TCS in patients with cerebellar ataxias for disease diagnosis and severity assessment.TCS on patients with genetic and acquired cerebellar ataxia, including 94 with spinocerebellar ataxias (SCAs) containing 10 asymptomatic carriers, 95 with cerebellar subtype of multiple system atrophy (MSA‐C), and 100 healthy controls (HC), was conducted. Assessments included third ventricle width, substantia nigra (SN) and lentiform nucleus (LN) echogenicity, along with comprehensive clinical evaluations and genetic testing.The study revealed significant TCS abnormalities in patients with cerebellar ataxia, such as enlarged third ventricle widths and elevated rates of hyperechogenic SN and LN. TCS showed high accuracy in distinguishing patients with SCA or MSA‐C from HC, with an AUC of 0.870 and 0.931, respectively. TCS abnormalities aided in identifying asymptomatic SCA carriers, effectively differentiating them from HC, with an AUC of 0.725. Furthermore, third ventricle width was significantly correlated with SARA and ICARS scores in patients with SCA3 and SCOPA‐AUT scores in patients with MSA‐C. The SN area and SARA or ICARS scores in patients with SCA3 were also positively correlated.Our findings illustrate remarkable TCS abnormalities in patients with cerebellar ataxia, serving as potential biomarkers for clinical diagnosis and progression assessment. [ABSTRACT FROM AUTHOR]

Autosomal dominant cerebellar ataxias (ADCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders primarily affecting the cerebellum. Nearly 33 genetically distinct subtypes have been defined, and 19 seemingly unrelated disease genes have been identified so far. Recently, mutations in the ATPase family gene 3-like 2 (AFG3L2) gene were presented to cause SCA28 subtype. In order to define the frequency of SCA28 mutation in Chinese mainland, we performed molecular genetic analysis in 67 unrelated affected individuals with ADCA. At last, we did not find AFG3L2 gene mutation, except for three known single nucleotide polymorphisms (SNP)s. It suggests that SCA28 subtype is very rare in Chinese mainland. [ABSTRACT FROM AUTHOR]

The form of Charcot-Marie-Tooth (CMT) neuropathy that maps to Xq13 is X-linked dominant, or X-linked intermediate. Heterozygous females are more mildly affected than hemizygous males. It has been known that this type of CMT is caused by mutations of connexin32 (Cx32) gene. A typical X-linked recessive Charcot Marie Tooth Chinese family was analyzed with single strand conformation polymorphism method. A Cx32 gene point mutation, Arg15Gln, in exon 2 was identified in all affected family members, suggesting that this mutation is responsible for the CMT incidence of this family. [ABSTRACT FROM AUTHOR]

Calcium-independent phospholipase A 2 β (iPLA 2 β), a member of the phospholipase A2 (PLA2s) superfamily, is encoded by the PLA2G6 gene. Mutations in the PLA2G6 gene have been identified as the primary cause of infantile neuroaxonal dystrophy (INAD) and, less commonly, as a contributor to Parkinson's disease (PD). Recent studies have revealed that iPLA 2 β deficiency leads to neuroinflammation, iron accumulation, mitochondrial dysfunction, lipid dysregulation, and other pathological changes, forming a complex pathogenic network. These discoveries shed light on potential mechanisms underlying PLA2G6 -associated neurodegeneration (PLAN) and offer valuable insights for therapeutic development. This review provides a comprehensive analysis of the fundamental characteristics of iPLA 2 β, its association with neurodegeneration, the pathogenic mechanisms involved in PLAN, and potential targets for therapeutic intervention. It offers an overview of the latest advancements in this field, aiming to contribute to ongoing research endeavors and facilitate the development of effective therapies for PLAN. [Display omitted] • iPLA 2 β plays a crucial role in iron homeostasis, lipid metabolism, mitochondrial regulation. • Diverse functions of iPLA 2 β have implications for the pathogenesis of PLA2G6 -associated neurodegeneration. • Recent discoveries of novel mechanisms provide potential therapeutic implications for PLA2G6 -associated neurodegeneration. [ABSTRACT FROM AUTHOR]

Objective: A large number of studies have found that the prevalence of cognitive impairment varies in different regions. However, data on cognitive impairment in the Chinese population is still lacking. The goal of this study was to assess the prevalence of cognitive impairment among the elderly in a region of China and explore the associated risk factors. Methods: We performed a population‐based cross‐sectional survey from April to June 2022. Residents come from three villages and six urban communities in the county‐level city of Liuyang in southern China (N = 3233) and the coverage rate of our study population reached 73%. Participants were assessed with a series of clinical examinations and neuropsychological measures. A total of 2598 participants were selected after filtering out those under 60 years old or with incomplete data. Patients with cognitive impairment included those with mild cognitive impairment (MCI) or dementia who met standard diagnostic criteria. Results: The prevalence of cognitive impairment, MCI, and dementia among participants aged 60 years and older were 21.48% (95% CI, 19.90–23.10), 15.70% (95% CI, 14.30–17.10), and 5.77 (95% CI, 4.90–6.70), respectively. And residents in villagers were more likely to have cognitive impairment than in urban communities (p < 0.001). Age growth and education level were independent influencing factors for cognitive impairment in all populations (p < 0.001). For lifestyles factors, both smoking and drinking reduced the risk of cognitive impairment (p < 0.05), but when further quantified, the link disappeared. Moreover, having cerebrovascular disease and severe vision impairment were risk factors (p < 0.05). Conclusion: A representative prevalence of cognitive impairment, MCI, and dementia was found in the elderly Han Chinese population in Southern China. And we further explored the role of known risk factors, particularly in physical activity, smoking, and alcohol consumption. [ABSTRACT FROM AUTHOR]

Paroxysmal kinesigenic dyskinesia (PKD) is associated with a disturbance of neural circuit and network activities, while its neurophysiological characteristics have not been fully elucidated. This study utilized the high‐density electroencephalogram (hd‐EEG) signals to detect abnormal brain activity of PKD and provide a neural biomarker for its clinical diagnosis and PKD progression monitoring. The resting hd‐EEGs are recorded from two independent datasets and then source‐localized for measuring the oscillatory activities and function connectivity (FC) patterns of cortical and subcortical regions. The abnormal elevation of theta oscillation in wildly brain regions represents the most remarkable physiological feature for PKD and these changes returned to healthy control level in remission patients. Another remarkable feature of PKD is the decreased high‐gamma FCs in non‐remission patients. Subtype analyses report that increased theta oscillations may be related to the emotional factors of PKD, while the decreased high‐gamma FCs are related to the motor symptoms. Finally, the authors established connectome‐based predictive modelling and successfully identified the remission state in PKD patients in dataset 1 and dataset 2. The findings establish a clinically relevant electroencephalography profile of PKD and indicate that hd‐EEG can provide robust neural biomarkers to evaluate the prognosis of PKD. [ABSTRACT FROM AUTHOR]

Background: Neuroinflammation might contribute to the pathogenesis of multiple systemic atrophy (MSA). However, specific alterations in the peripheral inflammatory and immune profiles of patients with MSA remain unclear. Objectives: To determine the peripheral inflammatory and immune profiles of patients with MSA and their potential value as biomarkers for facilitating clinical diagnosis and monitoring disease severity. Methods: This cross‐sectional study included 235, 240, and 235 patients with MSA, patients with Parkinson's disease (PD), and healthy controls (HCs), respectively. Inflammatory and immune parameters were measured in peripheral blood, differences between groups were assessed, and clusters were analyzed. Associations between the parameters and clinical characteristics of MSA were assessed using Spearman and partial correlation analyses. Results: Significant differences were observed especially in monocytes, neutrophils‐to‐lymphocyte ratio (NLR) and neutrophils‐to‐lymphocyte ratio (MPV) between MSA patients and HCs (P < 0.01). Monocytes and uric acid (UA) levels were also significantly different between the MSA and PD patients (P < 0.05). The combination of NLR and MPV distinguished MSA‐P patients from HCs (areas under the curve = 0.824). In addition, complement components C4 and C3 were significantly correlated with the Scale Outcomes in PD for Autonomic Symptoms and Wexner scale, whereas immunoglobulin G (IgG) was significantly correlated with scores of Unified Multiple System Atrophy Rating Scale (P < 0.05). Conclusions: In MSA patients, monocytes, NLR and MPV might serve as potential diagnostic biomarkers, whereas MLR, C3, C4, and IgG significantly correlate with disease severity. © 2023 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Introduction: Recently, chloride channel CLIC‐like 1 (CLCC1) was reported to be a novel ALS‐related gene. We aimed to screen CLCC1 variants in our ALS cohort and further explore the genotype–phenotype correlation of CLCC1‐related ALS. Methods: We screened rare damaging variants in CLCC1 from our cohorts of 1005 ALS patients and 1224 healthy controls with whole‐exome sequencing in Central South China. Fisher's exact test was conducted for association analysis at the entire gene level and single variant level. Results: In total, four heterozygous missense variants in CLCC1 were identified from four unrelated sporadic ALS patients and predicted to be putative pathogenic by in silico tools and protein model prediction, accounting for 0.40% of all patients (4/1005). The four variants were c.A275C (p.Q92P), c.G1139A (p.R380K), c.C1244T (p.T415M), and c.G1328A (p.R443Q), respectively, which had not been reported in ALS patients previously. Three of four variants were located in exon 10. Patients harboring CLCC1 variants seemed to share a group of similar clinical features, including earlier age at onset, rapid progression, spinal onset, and vulnerable cognitive status. Statistically, we did not find CLCC1 to be associated with the risk of ALS at the entire gene level or single variant level. Conclusion: Our findings further expanded the genetic and clinical spectrum of CLCC1‐related ALS and provided more genetic evidence for anion channel involvement in the pathogenesis of ALS, but further investigations are needed to verify our findings. [ABSTRACT FROM AUTHOR]

• AD onset and progression were accompanied with an unappreciated serum autoantibody response. • Seven candidate serum AD-specific autoantibodies were identified. • A combinatory signature of the seven autoantibodies showed high accuracy in distinguishing AD. • The autoantibody alternation provide an opportunity to identify patients with MCI. Autoimmunity plays a key role in the pathogenesis of Alzheimer's disease (AD). However, whether autoantibodies in peripheral blood can be used as biomarkers for AD has been elusive. Serum samples were obtained from 1,686 participants, including 767 with AD, 146 with mild cognitive impairment (MCI), 255 with other neurodegenerative diseases, and 518 healthy controls. Specific autoantibodies were measured using a custom-made immunoassay. Multivariate support vector machine models were employed to investigate the correlation between serum autoantibody levels and disease states. As a result, seven candidate AD-specific autoantibodies were identified, including MAPT, DNAJC8, KDM4D, SERF1A, CDKN1A, AGER, and ASXL1. A classification model with high accuracy (area under the curve (AUC) = 0.94) was established. Importantly, these autoantibodies could distinguish AD from other neurodegenerative diseases and out-performed amyloid and tau protein concentrations in cerebrospinal fluid in predicting cognitive decline (P < 0.001). This study indicated that AD onset and progression are possibly accompanied by an unappreciated serum autoantibody response. Therefore, future studies could optimize its application as a convenient biomarker for the early detection of AD. [ABSTRACT FROM AUTHOR]

Background: Spinocerebellar ataxia type 3 (SCA3) is the most common subtype of SCA without effective treatment. This study aimed to evaluate the comparative efficacy of low-frequency repetitive transcranial magnetic stimulation (rTMS) and intermittent Theta Burst Stimulation (iTBS) in a larger cohort of SCA3 patients. Methods: One hundred and twenty patients with SCA3 were randomly assigned to the 3 groups: 40 patients in the 1 Hz rTMS, 40 in the iTBS and 40 in the sham group. Patients underwent 10 sessions of rTMS targeting the cerebellum delivering for 5 consecutive days per week for 2 weeks (a total of 1200 pulses per session). Primary outcomes included the Scale for the Assessment and Rating of Ataxia (SARA) and the International Cooperative Ataxia Rating Scale (ICARS). Secondary outcomes included 10-m walking test (10MWT), nine-hole peg test (9-HPT), and PATA Rate Test (PRT). Outcome assessments were performed at baseline and on the last day of rTMS intervention. Results: This study revealed that active rTMS outperformed sham in reducing the SARA and ICARS scores in SCA3 patients, but with no difference between the 1 Hz rTMS and iTBS protocol. Moreover, no significant differences were observed in SARA and ICARS scores between the mild and moderate to severe groups after the 1 Hz rTMS/iTBS therapy. Additionally, no severe adverse events were recorded in this study. Conclusions: The study concluded that both 1 Hz rTMS and iTBS interventions targeting the cerebellum are effective to improve the symptoms of ataxia in patients with SCA3. [ABSTRACT FROM AUTHOR]

To investigate the risk factors for REM sleep behavior disorder (RBD) in a case-control study. Participants with probable RBD (pRBD) were defined using the RBD Questionnaire–Hong Kong (RBDQ-HK). Controls were collected by matching age and sex. Demographic information, lifestyle, comorbidity, prodromal symptoms of Parkinson's disease (PD), and blood biomarkers were assessed. The associations between these factors and pRBD were investigated by logistic regression. Partial correlation analysis was used to assess the association between the severity of RBD and depression. A total of 278 pRBD participants (age = 58.31 ± 15.82 years) and 556 controls (age = 58.16 ± 15.84 years) were enrolled in this study. Patients with pRBD were more likely to be current alcohol drinkers (OR 1.50, 95% CI 1.0–2.32). Participants with pRBD had a higher Hamilton Depression Rating Scale (HAMD-17) score (OR 1.17, 95% CI 1.11–1.22) than controls and were more likely to report arthritis (OR 1.53, 95% CI 1.08–2.16), constipation (OR 1.93, 95% CI 1.31–2.86), hyposmia (OR 1.71, 95% CI 1.10–2.67), and depression (OR 3.15, 95% CI 2.17–4.58). Higher levels of total cholesterol (OR 1.15, 95% CI 0.99–1.33) and low-density lipoprotein (OR 1.21, 95% CI 0.99–1.47) had borderline associations with pRBD. Additionally, the severity of pRBD was positively related to depression (r = 0.31, P < 0.01). We determined several risk factors for pRBD in this case-control study. Future studies are needed to understand the mechanism underlying the association between these factors and pRBD. • Patients with pRBD were more likely to be current alcohol drinkers. • Participants with pRBD had a higher HAMD-17 score than controls and were more likely to report arthritis, constipation, hyposmia, and depression. • Higher levels of total cholesterol and low-density lipoprotein had borderline associations with pRBD. [ABSTRACT FROM AUTHOR]

With complicated conditions and a large number of potentially causative genes, the diagnosis of a patient with complex inherited peripheral neuropathies (IPNs) is challenging. To provide an overview of the genetic and clinical features of 39 families with complex IPNs from central south China and to optimize the molecular diagnosis approach to this group of heterogeneous diseases, a total of 39 index patients from unrelated families were enrolled, and detailed clinical data were collected. TTR Sanger sequencing, hereditary spastic paraplegia (HSP) gene panel, and dynamic mutation detection in spinocerebellar ataxia (SCAs) were performed according to the respective additional clinical features. Whole-exome sequencing (WES) was used in patients with negative or unclear results. Dynamic mutation detection in NOTCH2NLC and RCF1 was applied as a supplement to WES. As a result, an overall molecular diagnosis rate of 89.7% was achieved. All 21 patients with predominant autonomic dysfunction and multiple organ system involvement carried pathogenic variants in TTR, among which nine had c.349G > T (p.A97S) hotspot variants. Five out of 7 patients (71.4%) with muscle involvement harbored biallelic pathogenic variants in GNE. Five out of 6 patients (83.3%) with spasticity reached definite genetic causes in SACS, KIF5A, BSCL2, and KIAA0196, respectively. NOTCH2NLC GGC repeat expansions were identified in all three cases accompanied by chronic coughing and in one patient accompanied by cognitive impairment. The pathogenic variants, p.F284S and p.G111R in GNE, and p.K4326E in SACS, were first reported. In conclusion, transthyretin amyloidosis with polyneuropathy (ATTR-PN), GNE myopathy, and neuronal intranuclear inclusion disease (NIID) were the most common genotypes in this cohort of complex IPNs. NOTCH2NLC dynamic mutation testing should be added to the molecular diagnostic workflow. We expanded the genetic and related clinical spectrum of GNE myopathy and ARSACS by reporting novel variants. [ABSTRACT FROM AUTHOR]

Background: Glycoprotein nonmetastatic melanoma protein B (GPNMB) has been demonstrated to mediate pathogenicity in Parkinson's disease (PD) through interactions with α‐synuclein, and plasma GPNMB tended to be a novel biomarker for PD. Objective: The goal of this study was to investigate whether plasma GPNMB could act as a potential biomarker for the clinical diagnosis and severity monitoring of multiple system atrophy (MSA), another typical synucleinopathy. Methods: Plasma GPNMB levels in patients with MSA, patients with PD, and healthy control subjects (HCs) were quantified using enzyme‐linked immunosorbent assays. Results: A total of 204 patients with MSA, 65 patients with PD, and 207 HCs were enrolled. The plasma GPNMB levels in patients with MSA were similar to those in HCs (P = 0.251) but were significantly lower than those in patients with PD (P = 0.003). Moreover, there was no significant correlation detected between the plasma GPNMB levels and disease severity scores of patients with MSA. Conclusions: No evidence was detected for the biomarker potential of plasma GPNMB in MSA. © 2023 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder. An increasing number of researchers have found extra motor features in ALS, which are also called ALS-plus syndromes. Besides, a great majority of ALS patients also have cognitive impairment. However, clinical surveys of the frequency and genetic background of ALS-plus syndromes are rare, especially in China. Methods: We investigated a large cohort of 1015 patients with ALS, classifying them into six groups according to different extramotor symptoms and documenting their clinical manifestations. Meanwhile, based on their cognitive function, we divided these patients into two groups and compared demographic characteristics. Genetic screening for rare damage variants (RDVs) was also performed on 847 patients. Results: As a result, 16.75% of patients were identified with ALS-plus syndrome, and 49.5% of patients suffered cognitive impairment. ALS-plus group had lower ALSFRS-R scores, longer diagnostic delay time, and longer survival times, compared to ALS pure group. RDVs occurred less frequently in ALS-plus patients than in ALS-pure patients (P = 0.042) but showed no difference between ALS-cognitive impairment patients and ALS-cognitive normal patients. Besides, ALS-cognitive impairment group tends to harbour more ALS-plus symptoms than ALS-cognitive normal group (P = 0.001). Conclusion: In summary, ALS-plus patients in China are not rare and show multiple differences from ALS-pure patients in clinical and genetic features. Besides, ALS-cognitive impairment group tends to harbour more ALS-plus syndrome than ALS-cognitive normal group. Our observations correspond with the theory that ALS involves several diseases with different mechanisms and provide clinical validation. [ABSTRACT FROM AUTHOR]

Background: Nocturnal symptoms have a significant effect on the quality of life in Parkinson's disease (PD) patients. Objective: This study aimed to investigate the prevalence and associated factors of nocturnal symptoms in Chinese PD patients. Methods: This multicenter cross-sectional study included 1,500 patients with primary PD from 18 centers in China was carried out between February 2019 and February 2020. Questionnaires including Parkinson's disease sleep scale 2 (PDSS-2), Parkinson's disease questionnaire 8 (PDQ-8), Beck depression inventory (BDI), and generalized anxiety disorder scale 7 (GAD-7) were used to assess nocturnal symptoms, quality of life, depression, and anxiety. Results: Among 1,500 Chinese PD patients, 576 (38.4%) reported nocturnal symptoms. Of them, 59.2% were older than 65 years. The PDQ-8 total score was higher in patients with nocturnal symptoms (p < 0.01). Moderate and severe depression was reported more often in patients with nocturnal symptoms (p < 0.01), and the occurrence and severity of anxiety were higher as well (p < 0.01). Longer disease duration and higher Hoehn-Yahr (HY) stage were independently associated with nocturnal symptoms (p < 0.01). Education level, depression, disease course, HY stage, and nocturnal symptoms were related to the quality of life in Chinese PD patients (p < 0.01). Conclusion: Our study found that 38.4% of Chinese PD patients have nocturnal symptoms, even in early and mid-stage PD. Nocturnal symptoms were associated with worse quality of life and higher incidences of depression and anxiety. Nocturnal symptoms should be included in the assessment and care plan, especially in patients with longer disease courses and higher HY stages. [ABSTRACT FROM AUTHOR]

Aims: To study the brain metabolic signature in Chinese amyotrophic lateral sclerosis (ALS) patients and compare the difference in brain metabolic patterns between ALS with and without genetic variants. Methods: We included 146 patients with ALS and 128 healthy controls (HCs). All patients with ALS underwent genetic testing to screen for ALS related genetic variants and were then divided into genetic (n = 22) and nongenetic ALS (n = 93) subgroups. All participants underwent brain 18F‐FDG‐PET scans. Group comparisons were performed using the two‐sample t‐test model of SPM12. Results: We identified a large of hypometabolic clusters in ALS patients as compared with HCs, especially in the bilateral basal ganglia, midbrain, and cerebellum. Moreover, hypometabolism in the bilateral temporal lobe, precentral gyrus and hypermetabolism in the left anterior cingulate, occipital lobe, and bilateral frontal lobe were also found in ALS patients as compared with HCs. Compared with nongenetic ALS patients, genetic ALS patients showed hypometabolism in the right postcentral gyrus, precuneus, and middle occipital gyrus. The incidence of sensory disturbance in patients with genetic ALS was higher than that in patients with nongenetic ALS (5 of 22 [22.72%] vs. 7 of 93 [7.52%], p = 0.036). Conclusions: Our investigation provided unprecedented evidence of relative hypometabolism in the midbrain and cerebellum in ALS patients. Genetic ALS patients showed a specific signature of brain metabolism and a higher incidence of sensory disturbance, indicating that genetic factors may be an underlying cause affecting the brain metabolism and increasing the risk of sensory disturbance in ALS. [ABSTRACT FROM AUTHOR]

Objectives: Hereditary spastic paraplegia (HSP) is a genetically heterogeneous disease caused by over 70 genes, with a significant number of patients still genetically unsolved. In this study, we recruited a suspected HSP family characterized by spasticity, developmental delay, ataxia and hypomyelination, and intended to reveal its molecular etiology by whole exome sequencing (WES) and long‐read sequencing (LRS) analyses. Methods: WES was performed on 13 individuals of the family to identify the causative mutations, including analyses of SNVs (single‐nucleotide variants) and CNVs (copy number variants). Accurate circular consensus (CCS) long‐read sequencing (LRS) was used to verify the findings of CNV analysis from WES. Results: SNVs analysis identified a missense variant c.195G>T (p.E65D) of MORF4L2 at Xq22.2 co‐segregating in this family from WES data. Further CNVs analysis revealed a microdeletion, which was adjacent to the MORF4L2 gene, also co‐segregating in this family. LRS verified this microdeletion and confirmed the deletion range (chrX: 103,690,507–103,715,018, hg38) with high resolution at nucleotide level accuracy. Interpretations: In this study, we identified an Xq22.2 microdeletion (about 24.5 kb), which contains distal enhancers of the PLP1 gene, as a likely cause of SPG2 in this family. The lack of distal enhancers may result in transcriptional repression of PLP1 in oligodendrocytes, potentially affecting its role in the maintenance of myelin, and causing SPG2 phenotype. This study has highlighted the importance of noncoding genomic alterations in the genetic etiology of SPG2. [ABSTRACT FROM AUTHOR]

Background: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder characterized by widespread intranuclear inclusions in the nervous system as well as multiple visceral organs. In 2019, expanded GGC repeats within the 5′ untranslated region of the NOTCH2NLC gene was identified as the causative factor. NIID is a heterogeneous disorder with variable clinical manifestations including cognitive impairment, cerebellar ataxia, parkinsonism, paroxysmal symptoms, autonomic dysfunction, and muscle weakness. Although NIID primarily affects the central and peripheral nervous systems, growing evidence suggests potential cardiac abnormalities in NIID. However, the link between expanded GGC repeats within NOTCH2NLC and cardiac dysfunction remains uncertain. Results: In this study, we utilized two transgenic mouse models, expressing NOTCH2NLC-(GGC)98 ubiquitously or specifically in cardiomyocytes, and identified p62 (also known as sequestosome 1, SQSTM1)-positive intranuclear NOTCH2NLC-polyG inclusions in cardiomyocytes in two mouse models. We observed that both models exhibited cardiac-related pathological and echocardiographic changes, albeit exhibiting varying degrees of severity. Transcriptomic analysis revealed shared downregulation of genes related to ion channels and mitochondria in both models, with the cardiomyocyte-specific mice showing a more pronounced downregulation of mitochondria and energy metabolism-related pathways. Further investigations revealed decreased expression of mitochondria-related genes and electron transport chain activity. At last, we conducted a retrospective review of cardiac-related examination results from NIID patients at our hospital and also identified some cardiac abnormalities in NIID patients. Conclusions: Our study provided the first in vivo evidence linking GGC repeat expansions within NOTCH2NLC to cardiac abnormalities and highlighted the contribution of mitochondrial dysfunction in the development of cardiac abnormalities. [ABSTRACT FROM AUTHOR]

Mutations in TMEM230 were identified as a genetic factor for Parkinson's disease (PD) with typical clinical symptoms and Lewy bodies in a North American population, and a highly prevalent TMEM230 mutation, c.550_552delTAGinsCCCGGG (p.*184ProGlyext*5), was found in 7 Chinese families. In the present study, we investigated the prevalence of TMEM230 mutations in a large cohort of Chinese PD patients and healthy controls individuals from mainland China. We sequenced all exons and exon–intron boundaries of TMEM230 in Chinese Han population including 1235 patients with PD and 1252 healthy control individuals. As a result, we did not detect any pathogenic mutation of TMEM230 in 192 probands with familial PD or 1043 sporadic PD patients. However, we did detect a synonymous variant c.357G>A p.Gly119Gly in a case of familial PD and the 3′ UTR+3G>T variant in 2 sporadic PD patients. These results suggested that TMEM230 mutation may not be a common genetic factor for Chinese familial and sporadic PD patients. [ABSTRACT FROM AUTHOR]

Highlights • Methods used to identify genetic modifiers in polyglutamine diseases have progressed from candidate genes to unbiased genome-wide searches. • Unbiased genome-wide searches may disclose small cumulative effects of key genes and modifying pathways. • Variable results from candidate genes may be due to difference in population heterogeneity, population stratification and study design. • Incorporating network-based strategy may broaden exploration of disease pathophysiology, phenotype prediction and therapeutical target. Abstract Polyglutamine (polyQ) diseases are a group of clinically and genetically heterogeneous neurodegenerative diseases. Expansion size correlates with age-at-onset (AO) and severity, and shows a critical threshold for each polyQ disease. Although an expanded CAG tract is sufficient to trigger disease, not all variation in AO is explained by (CAG) n length, which suggests the contribution of other modifying factors. Methods used to identify genetic modifiers in polyQ diseases have progressed from candidate genes to unbiased genome-wide searches. Inconsistency of results from candidate-genes studies are partly explained by sample size, study design and variable population frequency of "polymorphisms"; a genome-wide search may help elucidating more precise disease mechanisms underlying specific interaction networks. We review known genetic modifiers for polyQ diseases, and discuss developing strategies to find modulation, from common variants to networks disclosing small cumulative effects of key genes and modifying pathways. This may lead to a better understanding of genotype-phenotype correlation and the proposal of new potential targets for therapeutical interventions. [ABSTRACT FROM AUTHOR]

Multiple system atrophy (MSA) is a fatal progressive neurodegenerative disease. Biomarkers are urgently required for MSA to improve the diagnostic and prognostic accuracy in clinic and facilitate the development and monitoring of disease-modifying therapies. In recent years, significant research efforts have been made in exploring multidimensional biomarkers for MSA. However, currently few biomarkers are available in clinic. In this review, we systematically summarize the latest advances in multidimensional biomarkers for MSA, including biomarkers in fluids, tissues and gut microbiota as well as imaging biomarkers. Future directions for exploration of novel biomarkers and promotion of implementation in clinic are also discussed. [ABSTRACT FROM AUTHOR]

Introduction: Rasagiline is indicated for treating idiopathic Parkinson's disease (PD) as monotherapy and adjunct therapy to levodopa in patients. Objectives: To assess the post-marketing safety and tolerability of rasagiline in Chinese PD patients, as well as its effectiveness in improving motor symptoms. Methods: This prospective, non-interventional, multicenter, cohort study included PD patients administered rasagiline monotherapy or adjunct therapy to levodopa. The primary outcome was the incidence of adverse drug reactions (ADRs) according to MedDRA® (version 22.0), and the secondary outcomes were the Parkinson's Disease Unified Rating Scale (UPDRS) part III, Clinical Global Impression-Severity (CGI-S), and Clinical Global Impression-Global-Improvement (CGI-I), assessed at Weeks 4, 12, and 24. Results: In total, 734 patients, 95 in the monotherapy subgroup and 639 in the adjunct therapy subgroup, were included in the safety population. The incidence rates of all ADRs were comparable between the monotherapy (15.8%) and adjunct therapy (13.6%) subgroups. The most common ADRs by system organ class were nervous system disorders (5.6%), gastrointestinal disorders (3.3%), psychiatric disorders (1.8%), vascular disorders (1.2%), and general disorders and administration site conditions (1.1%). Five (0.7%) participants experienced 5 serious ADRs. Improvements in UPDRS part III, CGI-S and CGI-I at Weeks 4, 12 and 24 from baseline were observed. Conclusions: Safety data in this study indicated no extra safety concerns. Rasagiline is generally safe and well tolerated in Chinese PD patients. The safety profile and tolerability were in line with the established safety profile. Moreover, rasagiline reduced the severity of PD motor symptoms, confirming findings by previous clinical trials. [ABSTRACT FROM AUTHOR]

Background: Studies of glymphatic dysfunction in Parkinson's disease (PD) patients have attracted much attention in recent years. However, the relationships between glymphatic dysfunction and clinical symptoms remains unclear. Objectives: To determine whether the diffusion tensor image analysis along the perivascular space (DTI-ALPS) affect the severity and types of motor and non-motor symptoms in PD patients. Methods: De novo PD patients and controls who performed both DTI and 123I-DaTscan single photon emission computed tomography (SPECT) scanning were retrieved from the international multicenter Parkinson's Progression Marker Initiative (PPMI) cohort. Glymphatic system was evaluated by the DTI-ALPS. Motor symptoms were assessed by Movement Disorders Society Unified Parkinson's Disease Rating Scale III (MDS-UPDRS-III). The influence of glymphatic activity on motor and non-motor symptoms was explored by multivariate linear regression models. Results: A total of 153 PD patients (mean age 60.97 ± 9.47 years; 99 male) and 67 normal controls (mean age 60.10 ± 10.562 years; 43 male) were included. The DTI-ALPS index of PD patients was significantly lower than normal controls (Z = − 2.160, p = 0.031). MDS-UPDRS III score (r = − 0.213, p = 0.008) and subscore for rigidity (r = − 0.177, p = 0.029) were negatively correlated with DTI-ALPS index. The DTI-ALPS index was significantly associated with MDS-UPDRS-III score (β = − 0.160, p = 0.048) and subscore for rigidity (β = − 0.170, p = 0.041) after adjusting for putamen dopamine transporter availability and clinical factors. Conclusions: Our results showed distinct relationships between glymphatic dysfunction and the severity and types of PD motor symptoms, suggesting the potential of DTI-ALPS index as a biomarker for PD motor symptoms. [ABSTRACT FROM AUTHOR]

Cerebral small vessel disease (CSVD) is a prominent cause of ischemic and hemorrhagic stroke and a leading cause of vascular dementia, affecting small penetrating vessels of the brain. Despite current advances in genetic susceptibility studies, challenges remain in defining the causative genes and the underlying pathophysiological mechanisms. Here, we reported that the ARHGEF15 gene was a causal gene linked to autosomal dominant inherited CSVD. We identified one heterozygous nonsynonymous mutation of the ARHGEF15 gene that cosegregated completely in two families with CSVD, and a heterozygous nonsynonymous mutation and a stop-gain mutation in two individuals with sporadic CSVD, respectively. Intriguingly, clinical imaging and pathological findings displayed severe osteoporosis and even osteoporotic fractures in all the ARHGEF15 mutation carriers. In vitro experiments indicated that ARHGEF15 mutations resulted in RhoA/ROCK2 inactivation-induced F-actin cytoskeleton disorganization in vascular smooth muscle cells and endothelial cells and osteoblast dysfunction by inhibiting the Wnt/β-catenin signaling pathway in osteoblast cells. Furthermore, Arhgef15-e(V368M)1 transgenic mice developed CSVD-like pathological and behavioral phenotypes, accompanied by severe osteoporosis. Taken together, our findings provide strong evidence that loss-of-function mutations of the ARHGEF15 gene cause CSVD accompanied by osteoporotic fracture. [ABSTRACT FROM AUTHOR]

Abstract: Mutations of 3 causative genes, namely presenilin 1 (PSEN1), presenilin 2 (PSEN2), and amyloid precursor protein (APP), have been identified as the major causes of early-onset familial Alzheimer's disease (EOFAD). Recently, a GGGGCC repeat expansion in the noncoding region of C9orf72 was also detected in some patients with clinically diagnosed familial Alzheimer's disease. The prevalence of causative gene mutations in patients with EOFAD has been reported in previous studies but their prevalence remains unclear in Mainland China. The aim of this study was to characterize the common causative gene mutation spectrum and genotype-phenotype correlations in Chinese patients with EOFAD. Genetic screening for mutations in PSEN1, PSEN2, and APP was conducted in a total of 32 families with clinical diagnoses of EOFAD from Mainland China. Subsequently, a hexanucleotide repeat expansion in C9orf72 was detected in all patients. Four novel mutations in PSEN1 (p.A434T, p.I167del, p.F105C, and p.L248P) were identified in 4 respective families, and 1 previously recognized pathogenic mutation in APP (p.V717I) was detected in another 2 unrelated families. The PSEN2 mutation and pathogenic repeat expansions of C9orf72 were not detected in all patients. To the best of our knowledge, this is the first cohort report of a causative gene screen in patients with EOFAD in Mainland China. The analysis of the genetic-clinical correlations in this cohort supports the idea that the clinical phenotype might be influenced by specific genetic defects. [Copyright &y& Elsevier]

Abstract: The GGGGCC repeat expansion in the C9orf72 gene was recently identified as a major cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) in white populations. To estimate the frequency of hexanucleotide repeats in patients with ALS and FTD from mainland China, we screened for C9orf72 in a cohort of 128 patients and 150 control subjects using the repeat-primed polymerase chain reaction method. We observed pathogenic repeat expansions in a family with ALS-FTD and in a patient with sporadic FTD. In the family with ALS-FTD, the proband and the 2 asymptomatic siblings exhibited C9orf72 repeat expansions, and the clinical feature of the proband was characterized by pure motor syndrome with no cognitive impairment. The patient with sporadic FTD presented primarily with deteriorating behavior and mental status. Genotype analysis revealed that the proband shared the previously reported 20-single nucleotide polymorphism risk haplotype, whereas the patient with sporadic FTD carried all single nucleotide polymorphisms except rs2814707-A. To our knowledge, this study is the first to report 2 C9orf72 mutation patients in mainland China, and they shared the similar risk haplotype identified in white populations, suggesting that ALS and FTD associated with C9orf72 mutation was probably derived from a single founder. [Copyright &y& Elsevier]

Background: Neuronal Intranuclear Inclusion Disease (NIID) is a degenerative disease with heterogeneous clinical manifestations. We aim to analysis the relationship between clinical manifestations, neuroimaging and skin pathology in a Chinese NIID cohort. Methods: Patients were recruited from a Chinese cohort. Detail clinical information were collected. Visual rating scale was used for evaluation of neuroimaging. The relationship between clinical presentations and neuroimaging, as well as skin pathology was statistically analyzed. Results: Thirty-two patients were recruited. The average onset age was 54.3 y/o. 28.1% had positive family history. Dementia, autonomic nervous system dysfunction, episodic attacks were three main presentations. CSF analysis including Aβ42 and tau level was almost normal. The most frequently involved on MRI was periventricular white matter (100%), frontal subcortical and deep white matter (96.6%), corpus callosum (93.1%) and external capsule (72.4%). Corticomedullary junction DWI high intensity was found in 87.1% patients. Frontal and external capsule DWI high intensity connected to form a "kite-like" specific image. Severity of dementia was significantly related to leukoencephalopathy (r = 0.465, p = 0.0254), but not cortical atrophy and ventricular enlargement. Grey matter lesions were significantly associated with encephalopathy like attacks (p = 0.00077) but not stroke like attacks. The density of intranuclear inclusions in skin biopsy was not associated with disease duration, severity of leukoencephalopathy and dementia. Conclusions: Specific distribution of leukoencephalopathy and DWI high intensity were indicative. Leukoencephalopathy and subcortical mechanism were critical in pathogenesis of NIID. Irrelevant of inclusion density and clinical map suggested the direct pathogenic factor need further investigation. [ABSTRACT FROM AUTHOR]

Background: Amyotrophic lateral sclerosis (ALS) is a devastating progressive neurodegenerative disease that affects neurons in the central nervous system and the spinal cord. As in many other neurodegenerative disorders, the genetic risk factors and pathogenesis of ALS involve dysregulation of cytoskeleton and neuronal transport. Notably, sensory and motor neuron diseases such as hereditary sensory and autonomic neuropathy type 2 (HSAN2) and spastic paraplegia 30 (SPG30) share several causative genes with ALS, as well as having common clinical phenotypes. KIF1A encodes a kinesin 3 motor that transports presynaptic vesicle precursors (SVPs) and dense core vesicles and has been reported as a causative gene for HSAN2 and SPG30. Methods: Here, we analyzed whole-exome sequencing data from 941 patients with ALS to investigate the genetic association of KIF1A with ALS. Results: We identified rare damage variants (RDVs) in the KIF1A gene associated with ALS and delineated the clinical characteristics of ALS patients with KIF1A RDVs. Clinically, these patients tended to exhibit sensory disturbance. Interestingly, the majority of these variants are located at the C-terminal cargo-binding region of the KIF1A protein. Functional examination revealed that the ALS-associated KIF1A variants located in the C-terminal region preferentially enhanced the binding of SVPs containing RAB3A, VAMP2, and synaptophysin. Expression of several disease-related KIF1A mutants in cultured mouse cortical neurons led to enhanced colocalization of RAB3A or VAMP2 with the KIF1A motor. Conclusions: Our study highlighted the importance of KIF1A motor-mediated transport in the pathogenesis of ALS, indicating KIF1A as an important player in the oligogenic scenario of ALS. [ABSTRACT FROM AUTHOR]

Aims: We mainly evaluate retinal alterations in Alzheimer's disease (AD) patients, investigate the associations between retinal changes with AD biomarkers, and explore an optimal machine learning (ML) model for AD diagnosis based on retinal thickness. Methods: A total of 159 AD patients and 299 healthy controls were enrolled. The retinal parameters of each participant were measured using optical coherence tomography (OCT). Additionally, cognitive impairment severity, brain atrophy, and cerebrospinal fluid (CSF) biomarkers were measured in AD patients. Results: AD patients demonstrated a significant decrease in the average, superior, and inferior quadrant peripapillary retinal nerve fiber layer, macular retinal nerve fiber layer, ganglion cell layer (GCL), inner plexiform layer (IPL) thicknesses, as well as total macular volume (TMV) (all p < 0.05). Moreover, TMV was positively associated with Mini‐Mental State Examination and Montreal Cognitive Assessment scores, IPL thickness was correlated negatively with the medial temporal lobe atrophy score, and the GCL thickness was positively correlated with CSF Aβ42/Aβ40 and negatively associated with p‐tau level. Based on the significantly decreased OCT variables between both groups, the XGBoost algorithm exhibited the best diagnostic performance for AD, whose four references, including accuracy, area under the curve, f1 score, and recall, ranged from 0.69 to 0.74. Moreover, the macular retinal thickness exhibited an absolute superiority for AD diagnosis compared with other enrolled variables in all ML models. Conclusion: We identified the retinal alterations in AD patients and found that macular thickness and volume were associated with AD severity and biomarkers. Furthermore, we confirmed that OCT combined with ML could serve as a potential diagnostic tool for AD. [ABSTRACT FROM AUTHOR]

Background and purpose: NOTCH2NLC GGC repeat expansions have been identified to be associated with essential tremor (ET). Our aim was to characterize ET patients with NOTCH2NLC repeat expansions versus non‐expansions and describe distinctive clinical features of repeat expanded patients with long‐term follow‐up according to the new tremor classification. Methods: Participants included 597 ET pedigrees, 412 sporadic cases and 1085 healthy controls. Repeat expansions of GGC in NOTCH2NLC were screened, and comprehensive clinical features were investigated. A longitudinal clinical assessment and reclassification were performed in NOTCH2NLC expanded patients. Results: In total, 27 ET pedigrees (27/597) and three sporadic patients (3/412) were identified with pathogenic NOTCH2NLC GGC repeat expansions (≥60 repeats). Intermediate‐length GGC repeats (41–59 repeats) were found in four sporadic ET cases and one control subject, and the frequency was higher than that in control participants (4/412 vs. 1/1085, p = 0.022). About 46 ET patients (43 familial cases from 27 pedigrees and three sporadic cases) with NOTCH2NLC GGC repeat expansions had higher Essential Tremor Rating Assessment Scale I, Essential Tremor Rating Assessment Scale II and Non‐Motor Symptoms Scale scores and lower Mini‐Mental State Examination scores than the patients without expansions. Patients with pathogenic GGC repeats were reclassified as pure ET (25/46), ET‐plus (11/46) and ET‐neuronal intranuclear inclusion disease (10/46) subgroups at 2–8 years of follow‐up. Conclusion: Our results further supported that NOTCH2NLC GGC repeat expansions were associated with ET. Patients with pathogenic GGC repeats presented with more severe motor and non‐motor symptoms. Further long‐term follow‐up and subtype studies will help to define the role of NOTCH2NLC in ET. [ABSTRACT FROM AUTHOR]

Background: Freezing of gait (FOG) is a common, disabling symptom of Parkinson's disease (PD), and its exact pathophysiological mechanism is still poorly understood. The control of gait is a complex process that may be influenced by emotions modulated by serotonergic networks. Therefore, this study aimed to determine factors associated with FOG in PD patients and to evaluate the importance of the dorsal raphe nucleus (DRN; central node in the serotoninergic system) in FOG pathophysiology. Methods: We combined cross-sectional survey data from 453 PD patients. According to the Freezing of Gait Questionnaire (FOGQ), patients were divided into two groups: the "PD with frozen gait (PD-FOG)" and "PD without frozen gait (PD-nFOG)" groups. Demographic characteristics, clinical features, and motor and nonmotor symptoms (NMS) assessments of PD patients were recorded. Univariate statistical analysis was performed between the two groups, and then regression analysis was performed on related factors. We also acquired resting-state functional MRI (rs-fMRI) data from 20 PD-FOG, 21 PD-nFOG, and 22 healthy controls (HCs) who were randomly chosen. We defined seeds in the DRN to evaluate functional connectivity (FC) patterns. Results: The overall frequency of FOG was 11.9% patients in the PD-FOG group were older, had a longer disease duration, had a higher levodopa equivalent daily dose, had more severe motor symptoms and worse quality of life, had a higher proportion of dyskinesia, wearing-off and postural instability/gait difficulty (PIGD) clinical phenotype, and experienced more depression and impaired sleep function than those in the PD-nFOG group. Logistic regression analysis showed that H&Ystage ≥ 3, UPDRS-III scores, PIGD clinical phenotype and excessive daytime sleepiness were associated with FOG. In addition, there was significantly lower FC between the DRN and some cortical structures, including the supplementary motor area (SMA), left superior frontal gyrus (SFG), and left median cingulated cortex (MCC) in PD-FOG patients than HCs and PD-nFOG patients. Conclusions: These results demonstrate that the severity of PD and PIGD clinical phenotype are associated factors for freezing and that DRN dysfunction may play a key role in PD-related NMS and FOG. An abnormal cortical and brainstem networks may contribute to the mechanisms underlying FOG. [ABSTRACT FROM AUTHOR]

Introduction: Spinocerebellar ataxia type 3 (SCA3) is the most common subtype of hereditary ataxia. Few studies reported the CMCT features in SCA3, but with inconsistent findings. So far, CMCT in SCA3 remains largely unknown.Methods: This study included 86 SCA3 patients and 80 healthy controls. Motor-evoked potentials were recorded bilaterally from upper and lower limbs muscles by TMS using a double-cone coil attached to CCY-IA magnetic stimulator. CMCT was determined using F wave and paravertebral magnetic stimulation (PMS). The statistical analyses were performed using R software.Results: In our study, 36.5% of SCA3 patients had a slight prolongation of CMCT in lower limbs, but not upper limbs, uncorrelated with disease severity. Moreover, SCA3 patients with Babinski signs did not necessarily have abnormal CMCT, and vice versa. Our study demonstrated that PMS is a reliable method as F wave for detecting CMCT in SCA3. Additionally, CMCT to lower limbs was positively correlated with height, but not with age, sex, or weight in healthy controls.Conclusions: A small proportion of SCA3 patients had a slight prolongation of CMCT in lower limbs, but not upper limbs, uncorrelated with disease severity. Furthermore, CMCT measures were observed irrespective of pyramidal sign in SCA3; however, patients with abnormal CMCT had a higher incidence of the pyramidal sign. [ABSTRACT FROM AUTHOR]

Background: Some previous studies showed abnormal pathological and vascular changes in the retina of patients with Alzheimer's disease (AD). However, whether retinal microvascular density is a diagnostic indicator for AD remains unclear.Objective: This study evaluated the macular vessel density (m-VD) in the superficial capillary plexus and fovea avascular zone (FAZ) area in AD, explored their correlations with clinical parameters, and finally confirmed an optimal machine learning model for AD diagnosis.Methods: 77 patients with AD and 145 healthy controls (HCs) were enrolled. The m-VD and the FAZ area were measured using optical coherence tomography angiography (OCTA) in all participants. Additionally, AD underwent neuropsychological assessment, brain magnetic resonance imaging scan, cerebrospinal fluid (CSF) biomarker detection, and APOE ɛ4 genotyping. Finally, the performance of machine learning algorithms based on the OCTA measurements was evaluated by Python programming language.Results: The m-VD was noticeably decreased in AD compared with HCs. Moreover, m-VD in the fovea, superior inner, inferior inner, nasal inner subfields, and the whole inner ring declined significantly in mild AD, while it was more serious in moderate/severe AD. However, no significant difference in the FAZ was noted between AD and HCs. Furthermore, we found that m-VD exhibited a significant correlation with cognitive function, medial temporal atrophy and Fazekas scores, and APOE ɛ4 genotypes. No significant correlations were observed between m-VD and CSF biomarkers. Furthermore, results revealed the Adaptive boosting algorithm exhibited the best diagnostic performance for AD.Conclusion: Macular vascular density could serve as a diagnostic biomarker for AD. [ABSTRACT FROM AUTHOR]

Background: Amyotrophic lateral sclerosis (ALS) is a devastating progressive neurodegenerative disease that affects neurons in the central nervous system and the spinal cord. As in many other neurodegenerative disorders, the genetic risk factors and pathogenesis of ALS involve dysregulation of cytoskeleton and neuronal transport. Notably, sensory and motor neuron diseases such as hereditary sensory and autonomic neuropathy type 2 (HSAN2) and spastic paraplegia 30 (SPG30) share several causative genes with ALS, as well as having common clinical phenotypes. KIF1A encodes a kinesin 3 motor that transports presynaptic vesicle precursors (SVPs) and dense core vesicles and has been reported as a causative gene for HSAN2 and SPG30. Methods: Here, we analyzed whole-exome sequencing data from 941 patients with ALS to investigate the genetic association of KIF1A with ALS. Results: We identified rare damage variants (RDVs) in the KIF1A gene associated with ALS and delineated the clinical characteristics of ALS patients with KIF1A RDVs. Clinically, these patients tended to exhibit sensory disturbance. Interestingly, the majority of these variants are located at the C-terminal cargo-binding region of the KIF1A protein. Functional examination revealed that the ALS-associated KIF1A variants located in the C-terminal region preferentially enhanced the binding of SVPs containing RAB3A, VAMP2, and synaptophysin. Expression of several disease-related KIF1A mutants in cultured mouse cortical neurons led to enhanced colocalization of RAB3A or VAMP2 with the KIF1A motor. Conclusions: Our study highlighted the importance of KIF1A motor-mediated transport in the pathogenesis of ALS, indicating KIF1A as an important player in the oligogenic scenario of ALS. [ABSTRACT FROM AUTHOR]

Background and purpose: Synaptic loss is well established as the major correlate of characteristic and consistent pathology in amyotrophic lateral sclerosis (ALS). We aimed to assess the possible discriminant diagnostic value of 18F‐SynVesT‐1 positron emission tomography (PET) as a marker of ALS pathology and investigate whether specific synaptic density signatures are present in ALS with different subtypes. Methods: Twenty‐one patients with ALS and 25 healthy controls (HCs) were recruited. All participants underwent 18F‐SynVesT‐1‐PET. Synaptic density between ALS and HCs and between different ALS subgroups were compared. Correlation between synaptic density and clinical features in ALS was also analyzed. Results: Low uptake distribution was found in the group comprising 21 ALS patients as compared with HCs in the right temporal lobe and the bilateral inferior frontal gyrus, anterior cingulate, and hippocampus–insula region. We also found low uptake in the bilateral superior temporal gyrus, hippocampus–insula, anterior cingulate, and left inferior frontal gyrus in ALS patients with cognitive impairment compared to HCs. Furthermore, compared to spinal onset ALS, bulbar onset ALS showed low uptake in the bilateral cingulate gyrus and high uptake in the bilateral superior temporal gyrus and left occipital lobe. No significant result was found in correlation analysis. Conclusions: This approach may provide a direct measure of synaptic density, and it therefore might represent a potentially useful biomarker for ALS diagnosis, as well as for estimating the cognitive decline and site of onset in ALS. 18F‐SynVesT‐1‐PET is presently not justified as a routine investigation to detect evidence of brain dysfunction leading to progression in ALS. [ABSTRACT FROM AUTHOR]

Objectives: CYLD was a novel causative gene for frontotemporal dementia (FTD) and amyotrophic lateral sclerosis. Given the clinical and pathological overlap of FTD and Alzheimer's disease (AD), it is necessary to screen CYLD in AD patients and FTD patients in the Chinese population. Methods: In our study, using a targeted sequencing panel, we sequenced the CYLD gene in a large cohort of 2485 participants in the Chinese population, including 1008 AD patients, 105 FTD patients, and 1372 controls. Results: In the present study, the average onset age of AD and FTD patients was 66.84 ± 30.42 years old and 60 ± 10.00 years old, respectively. Our study reported three novel CYLD variants: p.Phe288Leu (patient No. 1, AD), p.Tyr485Phe (patients No. 6–9, all AD) and p.Thr951Ala (patient No. 10, AD), plus a previously reported variant: p.Arg397Ser (patient No. 2–5, AD and No. 11, FTD). These variants were absent in our in‐house controls and predicted to be deleterious according to the MutationTaster. The variant carriers were composed of 10 AD patients and one FTD patient, and the average onset age was 61.2 ± 10.9 years. The frequency of CYLD variants in AD was similar to that in FTD, which was 0.99% (10/1008) and 0.95% (1/105), respectively. Interpretation: Our finding extended the genotype and phenotype of the CYLD gene and demonstrated that CYLD rare damaging variants may be implicated in AD and FTD pathogenesis. [ABSTRACT FROM AUTHOR]

Background: Multiple system atrophy (MSA) is a progressive neurodegenerative disorder characterized by poorly levodopa-responsive parkinsonism, cerebellar ataxia, and autonomic dysfunction. Pathogenic mechanisms remain obscure, but the neuropathological hallmark is the presence of α-synuclein-positive glial cytoplasmic inclusions. Previous studies suggested that a single nucleotide polymorphism (SNP), rs11931074, in the α-synuclein gene, SNCA, had highly significant association with an increased risk of the development of MSA in the Caucasian subjects. In contrast, a Korean study failed to identify an association with disease risk. Methods: To study the effect of rs11931074 on MSA risk in a Chinese population, we conducted a case–control study and genotyped SNP rs11931074 by Sanger sequencing in 96 Chinese patients with MSA and 120 healthy controls. Moreover, we performed a meta-analysis on the topic. Results: There was no statistical difference in genotypes or allele frequencies of SNP rs11931074 between MSA and control groups in our cohort. The results of meta-analysis showed that the risk allele T of rs11931074 was associated with MSA (pooled odds ratio = 1.26, 95% confidence interval = 1.07–1.49, P = 0.006). Conclusions: Despite a positive result of the meta-analysis, the significant difference in frequency of allele T of rs11931074 between Asian and Caucasian subjects indicates that population heterogeneity at rs11931074 may exist. [ABSTRACT FROM AUTHOR]

Background: In polyglutamine (polyQ) diseases, the identification of modifiers and the construction of prediction model for progression facilitate genetic counseling, clinical management and therapeutic interventions.Methods: Data were derived from the longest longitudinal study, with 642 examinations by International Cooperative Ataxia Rating Scale (ICARS) from 82 SCA3 participants. Using different time scales of disease duration, we performed multiple different linear, quadratic and piece-wise linear growth models to fit the relationship between ICARS scores and duration. Models comparison was employed to determine the best-fitting model according to goodness-of-fit tests, and the analysis of variance among nested models.Results: An acceleration was detected after 13 years of duration: ICARS scores progressed 2.445 (SE: 0.185) points/year before and 3.547 (SE: 0.312) points/year after this deadline. Piece-wise growth model fitted better to studied data than other two types of models. The length of expanded CAG repeat (CAGexp) in ATXN3 gene significantly influenced progression. Age at onset of gait ataxia (AOga), a proxy for aging process, was not an independent modifier but affected the correlation between CAGexp and progression. Additionally, gender had no significant effect on progression rate of ICARS. The piece-wise growth models were determined as the predictive models, and ICARS predictions from related models were available.Conclusions: We first confirmed that ICARS progressed as a nonlinear pattern and varied according to different stages in SCA3. In addition to ATXN3 CAGexp, AOga or aging process regulated the progression by interacting with CAGexp. [ABSTRACT FROM AUTHOR]