Dementia With Lewy Bodies (DLB)

Progressive supranuclear palsy (PSP), mild cognitive impairment with Lewy bodies (MCI-LB), and Dementia with Lewy Bodies (DLB) are severe neurodegenerative diseases that cause significant motor impairment impacting daily function. Researchers at BioSensics, Johns Hopkins School of Medicine, Massachusetts General Hospital and their collaborators aim to conduct an analytical and clinical validation of wearable-based digital health technologies for monitoring upper and lower limb function in PSP, MCI-LB and DLB that could enable frequent, at-home monitoring and be incorporated into future clinical trials.

The goal of this observational study is to improve the detection of dementia with Lewy bodies (DLB) and its prodromal phases, as well as advancing our current understanding of biological mechanisms and therapeutic options. The data is acquired at cognitive clinics in Stockholm (Sweden) and combined with national and international data to increase statistical power, representativeness and replication of results. Participants undergo collection of clinical assessments, neuroimaging and fluid biomarkers.

This prospective observational study aims to identify and preliminarily validate molecular biomarkers, including microRNAs and metabolites, for the early differentiation of Parkinson's disease (PD) from atypical parkinsonian syndromes (APS). The study will enroll up to 100 patients with PD, 50 patients with suspected APS, and 50 healthy controls. Participants will undergo clinical assessments and provide blood, urine, and stool samples at baseline and after 12-18 months of follow-up. Molecular analyses, including microRNA profiling, metabolomics, RNA sequencing (RNA-seq), and microbiome analysis, will be performed to identify disease-specific diagnostic signatures. The primary objective is to detect differences in molecular profiles among patients with PD, patients with APS, and healthy controls. Secondary objectives include evaluating the diagnostic accuracy of biomarker panels and assessing longitudinal changes in these biomarkers over time. Although participants will not receive direct therapeutic benefits, the study may contribute to the development of non-invasive tools for the early diagnosis and improved differentiation of parkinsonian disorders.

The goal of this study is to use ultra-high-resolution (UHR) PET imaging to better understand how the brain and spinal cord change in healthy aging and in neurological and psychiatric disorders such as Alzheimer's disease (AD), Parkinson's disease and related movement disorders, amyotrophic lateral sclerosis (ALS), and psychotic disorders. Researchers will use the NeuroExplorer PET/CT system, a new scanner that can show very small structures in the brain and spinal cord in much more detail than regular PET. The main questions this study aims to answer are: * How do small but important brain regions (like the locus coeruleus, substantia nigra, and thalamic nuclei) change in healthy aging? * What early brain changes occur in neurodegenerative and psychotic disorders, and can they help improve early diagnosis? Participants will: * Undergo PET and MRI brain scans using different tracers that measure brain metabolism (18F-FDG), synaptic density (¹⁸F-SynVesT-1), dopamine transporters (¹⁸F-PE2I), and tau protein buildup (¹⁸F-MK6240). * Complete cognitive and clinical assessments related to memory, mood, and motor or psychiatric symptoms, depending on their group. This study will include healthy volunteers and patients with mild cognitive impairment due to Alzheimer´s disease, ALS, Parkinson's disease and related disorders, or psychotic disorders. The results will help create detailed brain imaging maps for healthy aging and identify early biomarkers for different diseases to support better diagnosis and treatment in the future.

The goal of this clinical trial is to test whether we can reliably and safely measure the accumulation of pathological protein α-synuclein \[involved in some diseases such as Parkinson's disease, Lewy body dementia and Multiple System Atrophy (MSA), collectively named α-synucleinopathies\] using a new positron emission tomography (PET) tracer called \[18F\]ACI-15916. Both healthy people and people with (suspected) α-synuclein pathology will participate to this trial. The main questions it aims to answer are: * whether \[18F\]ACI-15916 is safe and well tolerated when injected into participants * whether \[18F\]ACI-15916 reliably detects α-synuclein in the brain using PET technique. * whether there are differences in the amount of this protein between people with diseases related to α-synuclein accumulation in the brain and people without these diseases. Participants will: * Visit the clinic to consent to their participation and to ensure they are eligible \[physical and neurological examinations, questionnaires, blood and urine tests, ECG and in some cases a MRI and a PET scan with a licensed tracer (\[18F\]FE-PE2I) to confirm or not the disease\]. * Visit the clinic to receive the tracer \[18F\]ACI-15916 intravenously and be scanned in a PET scanner, during which blood will be collected (and optionally spinal fluid). * Receive a phone call from the clinic 1 week after the PET scan to report any symptoms and side-effects that they may be having. Some of the participants may be asked to come again to the clinic for a second PET scan with \[18F\]ACI-15916, allowing the researchers to determine if the measurements with the first PET scan are stable and reproducible. Some of the participants will participate in a specific part of the study to evaluate the distribution of the PET ligand in the whole body, with a similar visit schedule.

Alzheimer's disease and dementia with Lewy bodies (DLB) are the two main age-related neurodegenerative cognitive disorders. Differential diagnosis between these conditions is challenging, both at the prodromal and dementia stages. The lack of a precise diagnosis can be particularly harmful for patients with DLB, as up to 80% of them show severe adverse reactions to antipsychotic medications, including falls, confusion, and even death. The diagnosis of Alzheimer's disease has improved with cerebrospinal fluid (CSF) biomarkers such as Tau, phosphorylated Tau (P-Tau), and the Aβ42/Aβ40 ratio (Lehmann et al., 2018). However, differentiating Alzheimer's disease from DLB remains difficult: 1 to 3 Alzheimer's biomarkers are frequently positive in the CSF of patients with DLB: in 49% of cases at the prodromal stage and up to 72% at the dementia stage. Moreover, total α-synuclein measurement in CSF has not proven to be diagnostically reliable. The DAT-scan, sometimes used as a supportive tool, is an expensive technique and lacks sensitivity, with detection rates of only 78% in dementia-stage DLB and 54% in prodromal DLB. Given these limitations, identifying specific biomarkers for DLB, particularly pathological α-synuclein, is a critical objective. α-synuclein is the main protein component of Lewy bodies, whose abnormal β-sheet conformation promotes aggregation and prion-like propagation. Conventional measurements of total α-synuclein in CSF have failed to achieve sufficient diagnostic specificity. In contrast, detecting aggregated or pathological forms of α-synuclein in CSF appears to be a promising approach for improving the diagnosis of synucleinopathies. New techniques based on α-synuclein aggregation amplification have shown encouraging results in retrospective studies including neuropathologically confirmed cases (Bargar et al., 2021; Rossi et al., 2020). However, prospective evaluation of these methods in real-world clinical settings is still lacking. We hypothesize that a specific assay targeting pathological α-synuclein in CSF could reliably distinguish patients with DLB from those with Alzheimer's disease.