Skip to main content
OpenTrials
Recruiting

NCT Number: NCT04246437

[18F]F-DOPA Imaging in Patients With Autonomic Failure

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.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Autonomic Failure Autonomic Nervous System Diseases Basal Ganglia Diseases Brain Diseases Central Nervous System Diseases Dementia Dementia With Lewy Bodies Lewy Body Disease Mental Disorders Movement Disorders Multiple System Atrophy Nervous System Diseases Neurocognitive Disorders Neurodegenerative Diseases Parkinson Disease Parkinsonian Disorders Primary Dysautonomias Pure Autonomic Failure Synucleinopathies

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

Vanderbilt University Medical Center

Nashville, Tennessee, 37212, United States

Location status: Recruiting

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients with a diagnosis if pure autonomic failure
  • Patients with autonomic failure and possible PD, MSA, or DLB
  • Healthy adults aged 18 and above
  • Clinical exam confirming clinical designation

Exclusion criteria

  • Subjects who have any type of bioimplant activated by mechanical, electronic, or magnetic means (e.g., cochlear implants, pacemakers, neurostimulators, biostimulators, electronic infusion pumps, etc.), because such devices may be displaced or malfunction.
  • Subjects who have any type of ferromagnetic bioimplant that could potentially be displaced.
  • Subjects who have cerebral aneurysm clips.
  • Subjects who may have shrapnel imbedded in their bodies (such as from war wounds), metal workers and machinists (potential for metallic fragments in or near the eyes).
  • Subjects who are pregnant, because the effects of high field MRI on fetuses are not yet known.
  • Minors (younger than 18 years)

Also excluded are subjects incapable of giving informed written consent:

  • Subjects who cannot adhere to the experimental protocols for any reason, or have an inability to communicate with the researcher.
  • Subjects who have limited mental ability to give informed consent, mentally retarded, altered mental status, mental disability, confusion, or psychiatric disorders.
  • Prisoners

Treatment and study plan

[18F]FDOPA

Drug

Patients will receive a 3-D emission scan following a 6-8 mCi slow bolus injection of [18F]FDOPA over a 30 second period. Serial scans are started simultaneously with the bolus injection of radiotracer and are obtained for approximately 95 minutes.

Carbidopa 200mg oral dose

Drug

30 minutes prior to the PET scan, patients will receive the 200mg oral dose of carbidopa to prevent peripheral [18F]FDOPA metabolism to increase signal-to-noise ratio of the imaging.

Other names: Lodosyn

Entacapone 400mg oral dose

Drug

30 minutes prior to the PET scan, patients will receive the 400mg oral dose of entacapone to prevent peripheral [18F]FDOPA metabolism to increase signal-to-noise ratio of the imaging.

Other names: Comtan

Primary outcomes

  1. Differences in FDOPA uptake across patient populations

    Time frame: 95 minutes post-PET after start of PET imaging

    Specific FDOPA uptake, Ki, will be calculated via a reference Logan plot to provide voxelwise measurements of FDOPA uptake. Mean uptake will be assessed in brain regions-of-interest in 40 participants to assess potential differences across different autonomic failure-related diseases.

Study contacts

Contact information is provided by the study sponsor or research team.

Daniel O Claassen, MD, MS

CONTACT

[email protected]

615-936-1007

Kaitlyn O'Rourke, MS

CONTACT

[email protected]

Sponsors and collaborators

Lead sponsor

Daniel Claassen

Other

Registry information

Important dates

Study start
2020
Primary completion
2027
Study completion
2027
First posted
Jan 29, 2020
Registry last updated
Mar 16, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.