NCT04821830CompletedPhase 4
Vigor and the LDR in Parkinson Disease
Source: ClinicalTrials.gov · Last updated 18 Jul 2025
Brief summary (registry, in English)
Parkinson disease (PD) is a common disorder in which reduced speed of movement results from inadequate brain production of the chemical dopamine. The most effective treatment for PD is the drug levo-dopa, which partially replaces brain dopamine. Despite decades of successful use, how levo-dopa improves speed of movement in PD is not understood. This observational study recruits participants who have been prescribed levo-dopa by their treating physicians. Before their first dose, immediately after their first dose and later, when their dose has been stabilized, they will engage with the research team to participate in a few simple experiments to measure speed, grip strength, tremor, and stability (on and off of treatment). The purpose of these experiments is to understand how levo-dopa treatment in Parkinson disease enhances movement speed. An important but not understood component of levo-dopa action, the Long Duration Response (LDR), lasts for days to weeks. A basic function of dopamine signaling in the brain is modulation of motivation - the coupling between effort and action values. These experiments will determine if the LDR is associated with relative normalization of motivation function in the brain. The motivation behavior of recently diagnosed PD participants will be examined before and after treatment with levo-dopa to determine if the magnitude of the LDR is correlated with improvements in motivation behavior.
- Status (registry)
- Completed
- Phase (registry)
- Phase 4
- Study type
- Interventional
- Enrollment
- 19 (actual)
- First submitted
- 10 Mar 2021
- Start date
- 12 Feb 2020
- Primary completion date
- 25 Apr 2024
- Lead sponsor
- University of Michigan
- Diseases
- Parkinson disease
- NCT number
- NCT04821830
What you commit to
- Study type: Interventional · Phase 4
- Participants enrolled: 19
- From 12 Feb 2020 to the primary completion date, 25 Apr 2024
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Evidence of a stroke or mass lesion on prior structural brain imaging (MRI or CT)
Other illness
- The presence of other neurologic disease or findings on examination
- Evidence of any confounding medical or psychiatric problem that would preclude task participation.
- Participants with cognitive impairment that might impair their capacity to provide informed consent.
Other
- Depression: Geriatric Depression Scale score \>11
- Use of dopamine agonists or stimulants
Who the study is looking for
- Diagnosis of Parkinson Disease
- Previously Untreated or treated for \<4 weeks
- Mild to Moderate Parkinson disease (Hoehn \& Yahr Stages I-II)
- About to start treatment with a L-Dopa preparation (Sinemet)
Age in the registry: 45 years to 90 years · Sex: All · Does not accept healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| University of Michigan Coordinator of this site? Confirm its status | Ann Arbor | United States | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.