Prodromal Parkinson's Disease

The purpose of this research study is to identify the role that the gut-brain axis, the group of nerves that connect the brain and gut, plays in Parkinson's disease (PD). The National Institute of Diabetes and Digestive and Kidney Diseases is sponsoring this research study. During this study, specific groups of participants, also known as "cohorts", will be identified based on the severity of their PD. There will also be a cohort enrolling participants who do not have Parkinson's and a cohort enrolling participants that are at risk for developing PD. Each of these cohorts will be compared to the others to assess the differences in the gut-brain connection. Participants in this study will: * meet with a medical provider * answer questionnaires * give samples of blood, stool, and saliva * have X-rays taken while swallowing different foods (swallowing study) * have X-rays taken to see how long it takes markers to move through their colon (colon transit study) * have a flexible sigmoidoscopy, where a doctor looks inside the lower part of the colon and takes small tissue samples (biopsies) from the mucosa (lining) * have samples taken of their skin * have an anorectal manometry and a balloon expulsion test, where a small tube and balloon are placed in the rectum to measure muscle function. Participation in the study will last up to 24 months (2 years).

This study is a single-center, longitudinal study and will be conducted at the Institute for Neurodegenerative (INDD) Site in New Haven, CT. This study aims to recruit participants from the ongoing Parkinson's Progression Markers Initiative AV-133 Prodromal Imaging sub study \[PPMI 015\] to obtain a second comparison imaging scan. In addition to being imaged with the standard Positron Emission Tomography (PET) camera after the \[18F\]AV133 injection in the PPMI 015 sub study, participants agreeing to a second scan will be imaged with the NeuroEXPLORER (NX) PET camera per this protocol. This study will enroll approximately 25 participants at the INDD site. The dual PET scans will be completed at baseline, 1-and 2- years follow up. Participants may be asked to undergo further longitudinal scans based on the acquired study data. All participants will have longitudinal clinical, biomarker, and genetic data for correlation analyses to imaging data from the PPMI Clinical study.

Comprehensive characterization of early-stage Parkinson's disease in patients with REM sleep behavior disorder Parkinson's disease (PD) is the fastest-growing neurodegenerative disorder worldwide, significantly affecting quality of life and causing substantial social and economic burdens. Currently, treatments for Parkinson's disease primarily manage symptoms through medication and lifestyle changes but cannot stop disease progression. By the time Parkinson's disease is diagnosed, substantial nerve-cell loss has already occurred in specific brain areas. Identifying early signs of PD before symptoms fully develop is essential for improving future treatment strategies. This research project aims to deeply understand the earliest stages of Parkinson's disease by studying patients with REM sleep behavior disorder (RBD). RBD is a condition characterized by unusual movements or behaviors during dream sleep, caused by nerve-cell loss in the brainstem. Importantly, more than 80% of individuals with RBD eventually develop Parkinson's disease or related conditions, such as Dementia with Lewy Bodies or Multiple System Atrophy. Study Goals: Our study will examine multiple potential biomarkers (measurable indicators) that could help identify early stages of Parkinson's disease. These include: 1. Brain structure changes: The Investigators will use advanced imaging methods (7-Tesla MRI) to closely examine specific brain regions known to be affected early in Parkinson's disease, particularly the substantia nigra and the locus coeruleus (LC). The LC helps regulate sleep and wakefulness, and studies have shown it is damaged in patients with RBD and Parkinson's disease. Additionally, the investigators will use specialized imaging (Pe2i-PET and MIBG-scintigraphy) to measure dopamine availability and changes in heart nerve function. 2. Abnormal protein buildup (ɑ-synuclein): In Parkinson's disease, nerve-cell death is linked to abnormal clumping of a protein called ɑ-synuclein within cells. Detecting this abnormal protein buildup early might help identify who is at risk of developing Parkinson's disease. The investigators aim to explore how levels of ɑ-synuclein aggregation relate to other early signs of the disease. 3. Functional changes in brain and body: Polysomnography, an overnight sleep test recording brain (EEG) and heart (ECG) activity, is the best method for diagnosing RBD. The investigators will also measure brain activity during wakefulness to further understand early changes. 4. Symptoms and physical tests: Participants will undergo thorough clinical assessments, including motor and cognitive tests, as well as tests evaluating autonomic (automatic nervous system) function, such as cardiovascular responses using a tilt-table test. Together, these extensive assessments will provide a detailed understanding of how Parkinson's disease begins and progresses. This knowledge can greatly improve early diagnosis, allowing earlier and potentially more effective treatments for individuals at high risk. Study Design: The investigators will recruit: * 50 individuals diagnosed with REM sleep behavior disorder * 50 control participants without major psychiatric or neurological disease, matched by age and gender THe investigation team have a complete, detailed plan and will begin collecting data as soon as ethical approval is granted. Main Hypotheses: Although our extensive data will allow many analyses, the investigation team specifically predict: * Individuals with RBD will show more significant damage in the locus coeruleus compared to controls. * Greater damage in the locus coeruleus will correlate with more severe cognitive issues, sleep problems, and autonomic dysfunction. * Cognitive issues in RBD patients might correlate with specific patterns of damage in different parts of the locus coeruleus. For example, memory problems might be linked to more damage in the front (rostral) part of this region. Impact: This study will significantly enhance early detection of Parkinson's disease, paving the way for personalized medical approaches and potentially more effective treatments. Conducted by a multidisciplinary team of experts in brain imaging, sleep medicine, autonomic function, and protein aggregation, this research supports Denmark's leadership in precision clinical imaging and aligns closely with hospital research strategies aimed at understanding and treating chronic diseases. Ultimately, our goal is to improve personalized patient care for Parkinson's disease in the future.

The study is a longitudinal, multi-center study to assess progression of \[18F\] AV-133 imaging in Prodromal PD participants. Participants will be followed for up to 24 months. Approximately 100 Prodromal participants will be recruited from up to 10 sites. Participants will be comprehensively assessed at baseline and follow up. Participants will undergo imaging assessments with \[18F\] AV-133 and clinical (motor, neuropsychiatric, cognitive and imaging and biomarker) assessments (conducted under the PPMI Clinical protocol).

Early diagnosis of Neurodegenerative diseases (NDDs) and accurate patient profiling are key goals needed to tailor prompt personalized therapeutic strategies that can significantly impact disease progression and patients' quality of life. The project will validate a novel, cost-effective and quick biophotonic-based method for early and differential diagnosis of NDDs (Parkinson's disease, atypical parkinsonisms, Alzheimer's disease) and for routine clinical monitoring of NDD progression (longitudinal study). Raman spectroscopy (RS) will be applied to biochemically profile saliva and salivaderived Extracellular Vesicles (sEVs) and to identify a spectroscopic biomarker for NDDs. Optimized protocols for RS will be used to concomitantly evaluate saliva and sEVs from people with NDDs and to detect salivary changes in the biochemical profile, with special focus on EV-associated components. The accuracy of the method in discriminating NDDs at different disease stages and during disease progression will be verified. A nanotechnology-based biomolecular characterization of saliva and sEV will clarify the involvement of specific pathological molecules in NDDs progression.