Active clinical trials for "Synucleinopathies"

The aim of this study is to correlate baseline gut microbiota features and the progression of neurodegeneration in the established cohort of patients with early Parkinson's disease.

The study is a multi-center, observational study to evaluate the feasibility of α-synuclein-related biomarkers and imaging data in the disease diagnosis and prognosis evaluation in Synucleinopathies and healthy subjects.

This will be an observational study looking at clinical and biomarker characteristics in patients with Parkinson's Disease (PD), Multiple System Atrophy (MSA), Rapid Eye Movement Sleep Behavior Disorder (RBD), Normal Pressure Hydrocephalus and matched controls. Saliva, plasma, serum, urine, and cerebrospinal fluid (CSF) samples will be collected from participants.

This study will enroll participants with idiopathic rapid eye movement (REM) sleep behavior disorder (RBD), for the purpose of preparing for a clinical trial of neuroprotective treatments against synucleinopathies.

Excessive daytime sleepiness (EDS) is observed in 30 to 50 % of patients with Parkinson's disease (PD) patients, Dementia with Lewy Bodies (DLB) and Multiple System Atrophy (MSA). It is a major complain and represents a socially relevant problem as unintended episodes of sleep can also occur while driving for example. Arterial hypotension is frequently observed in patients with PD, DLB and MSA and considered as a marker of autonomic failure. Sleepiness is known to occur preferentially when patients are having arterial hypotension whatever the cause (i.e. postprandial period, administration of hypotensive medication such as dopamine agonists). We hypothesize that arterial hypotension is associated with abnormal sleepiness. We have observed this association in an on-going epidemiological survey Hyperglycaemia induced by oral glucose load - a standardized model simulating food intake during a meal - provokes arterial hypotension in the majority of Parkinson's disease patients with dysautonomia. It can be hypothesised that sleep attacks in these patients could be mediated by this fall in blood pressure.

REM sleep behavior disorder (typical or 'idiopathic' RBD, iRBD) is a novel and distinct parasomnia characterized by recurrent dream enactment behaviours and polysomnographic features of loss of normal REM-sleep related muscle atonia, with a male predominance commonly occurring at the age of 60's. A majority of the patients with iRBD will eventually develop α-synucleinopathy (e.g., Parkinson's disease). On the other hand, growing evidence reveals a specific group of psychiatric patients demonstrating comparable clinical RBD features (pRBD) (e.g., abnormal REM-related electromyographic (EMG) activities) as found in typical iRBD, but with less male predominance occurring at the age of mid 40's to early 50's. Although recent findings from both cross-sectional and prospective studies have suggested that pRBD is likely to be a persistent parasomnia with close association with clinical and neuroimaging biomarkers related to neurodegeneration, the nosology of the development of RBD symptoms among patients with psychiatric disorders, notably major depressive disorder, remains unclear as to whether they are simply antidepressants related, or represent a part of the early phase of α-synucleinopathy neurodegeneration. Family studies on iRBD have confirmed a significant familial aggregation of iRBD with a higher rate of RBD cases and presence of prodromal neurodegenerative biomarkers (e.g. tonic EMG activity during REM sleep, constipation, and motor function impairments) of α-synucleinopathy neurodegeneration among first-degree relatives (FDRs) of patients with iRBD. Thus, the investigators propose this family study to examine the following hypotheses: 1) FDRs of patients with pRBD have a higher rate of RBD symptoms and its core features when compared to FDRs of controls with and without psychiatric disorders; 2) FDRs of pRBD are more likely to exhibit the features associated with prodromal markers of α-synucleinopathy neurodegeneration when compared with FDRs of controls with and without psychiatric disorders; 3) FDRs of patients with pRBD have a higher rate of α-synucleinopathy neurodegeneration when compared with FDRs of controls with and without psychiatric disorders. A total of 176 FDRs from each group (e.g., pRBD cases, psychiatric controls, and healthy controls) will be recruited to undergo a face-to-face clinical interview and a series of assessments on prodromal markers of Parkinson's diseases (as according to the International Parkinson and Movement Disorder Society research criteria) respectively. All FDRs with possible RBD and a subset of FDRs without possible RBD will be invited to undergo one-night video-polysomnographic assessment to confirm the clinical diagnosis of RBD and to assess the abnormal REM-related EMG muscle activities.

With the global ageing population, neurodegenerative disorders including synucleinopathy are major burdens to patients, carers and society. Synucleinopathy refers to a group of neurodegenerative diseases characterized by abnormal aggregation of alpha-synuclein protein in the central nervous system (CNS). Common examples of synucleinopathy are Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Among all the premotor clinical markers that have been identified, a sleep disorder known as REM sleep behavior disorder (RBD) is associated with the highest likelihood ratio of developing PD. In addition, it has been shown that almost all RBD patients (over 80%) eventually developed neurodegenerative diseases after 14 years follow-up. Gut microbiota and synucleinopathy In recent years, several key studies have advanced our understanding regarding the roles that brain-gut-microbiota axis plays in the pathogenesis of brain diseases, including PD. It has been shown that gut microbiota is implicated in a series of pathophysiological changes in PD, including motor deficits, microglia activation, and αSyn pathology in mice model with overexpression of αSyn. Furthermore, some microbiotas, such as enterobacteriaceae, have been shown to be positively associated with the severity of PD symptoms, including postural instability and gait difficulty. Limitations in previous studies and knowledge gaps Nonetheless, the answers for several key questions regarding the roles of gut microbiota in the progression of synucleinopathy are still unclear. First, whether these microbiotas found in previous studies are the causes or the effects of PD. For example, medications treating PD may also affect the gut microbiome. Moreover, the microbiota may be affected by a number of factors commonly found in PD, such as constipation per se and diet. In this regard, an influential hypothesis of synucleinopahy was proposed by Braak et al at which the early premotor features including gastro-enterology symptoms, such as constipation and RBD would predate the onset of PD by some years. Thus, it is crucial to compare the microbiota among individuals at different stages of synucleinopathy. In view of slow progression of synucleinopathy and a relatively low prevalence of synucleinopathy in the general population, it is impractical to run a prospective study to examine this research question. Finally, gut microbiota is determined by both genetic and environmental factors. A family cohort design will help to understand the genetic and environmental influences on the association between microbiota and synucleinopathy.

This study is a prospective study with a mean of 5-year follow-up interval, aims to monitor the progression of α-synucleinopathy neurodegeneration by the evolution of prodromal markers and development of clinical disorders in first-degree relatives (FDRs) of idiopathic REM Sleep Behavior Disorder (RBD) patients and healthy controls.

Hypothesis is that the presence of a-synucleinopathy related non motor symptoms could be predictive factor for post-operative delirium. During 72hrs after spine surgery, investigator will observe occurrence of post-operative delirium, and analysis difference of a-synucleinopathy related non motor symptoms between 2 groups.