[18F]F-DOPA Imaging in Patients With Autonomic Failure
Status:
Recruiting
Trial end date:
2022-02-01
Target enrollment:
Participant gender:
Summary
Alpha-synucleinopathies refer to age-related neurodegenerative and dementing disorders,
characterized by the accumulation of alpha-synuclein in neurons and/or glia. The anatomical
location of alpha-synuclein inclusions (Lewy Bodies) and the pattern of progressive neuronal
death (e.g. caudal to rostral brainstem) give rise to distinct neurological phenotypes,
including Parkinson's disease (PD), Multiple System Atrophy (MSA), Dementia with Lewy Bodies
(DLB). Common to these disorders are the involvement of the central and peripheral autonomic
nervous system, where Pure Autonomic Failure (PAF) is thought (a) to be restricted to the
peripheral autonomic system, and (b) a clinical risk factor for the development of a central
synucleinopathy, and (c) an ideal model to assess biomarkers that predict phenoconversion to
PD, MSA, or DLB. Such biomarkers would aid in clinical trial inclusion criteria to ensure
assessments of disease- modifying strategies to, delay, or halt, the neurodegenerative
process. One of these biomarkers may be related to the neurotransmitter dopamine (DA) and
related changes in the substantia nigra (SN) and brainstem. [18F]F-DOPA is a radiolabeled
substrate for aromatic amino acid decarboxylase (AAADC), an enzyme involved in the production
of dopamine. Use of this radiolabeled substrate in positron emission tomography (PET) may
provide insight to changes in monoamine production and how they relate to specific
phenoconversions in PAF patients. Overall, this study aims to identify changes in dopamine
production in key regions including the SN, locus coeruleus, and brainstem to distinguish
between patients with PD, MSA, and DLB, which may provide vital information to predict
conversion from peripheral to central nervous system disease.