Vigor and the LDR in Parkinson Disease

NCT04821830 | Completed Phase 4 Results DMC FDA Drug

• 2 other identifiers: HUM00166765R21NS114749
• Study Type: interventional
• Target: 19
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Parkinson Disease

Keywords

Parkinson's Disease

Outcome Measures

Primary Outcomes (11)

• Tapping Speed Task - Experiment 1

  Measurement of bradykinesia. With the hand most affected by PD, participants were instructed to alternately tap 2 manual counters spaced 20 cm apart as rapidly as possible for 1 minute. The longer participants took to complete the task indicated a higher degree of bradykinesia affecting them. This task was administered over the course of 4 visits during the following conditions: Visit 1. Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2. After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3. 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4. After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa).

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• Value Driven Attentional Oculomotor Capture Task - Experiment 2 - No Distractor Value

  Participants did a saccadic eye movement task involving rapid-eye movements from one point to another to assess the functionality of eye muscles and the brain's ability to control these movements. Participants had an initial training session and then had to complete the task with no distractors, low distractors, and high distractors. This task was administered over the course of 4 visits during the following conditions: Visit 1. Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2. After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3. 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4. After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa).

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• Value Driven Attentional Oculomotor Capture Task - Experiment 2 - Low Distractor Value

  Participants did a saccadic eye movement task involving rapid-eye movements from one point to another to assess the functionality of eye muscles and the brain's ability to control these movements. Participants had an initial training session and then had to complete the task with no distractors, low distractors, and high distractors. This task was administered over the course of 4 visits during the following conditions: Visit 1. Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2. After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3. 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4. After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa).

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• Value Driven Attentional Oculomotor Capture Task - Experiment 2 - High Distractor Value

  Participants did a saccadic eye movement task involving rapid-eye movements from one point to another to assess the functionality of eye muscles and the brain's ability to control these movements. Participants had an initial training session and then had to complete the task with no distractors, low distractors, and high distractors. This task was administered over the course of 4 visits during the following conditions: Visit 1. Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2. After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3. 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4. After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa).

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• Joystick Movement Task - Experiment 1 - Low Incentive

  All participants were tasked with pushing a joystick with the hand most affected by PD symptoms in response to monetary incentives. Participants were presented with incentives of low ($5), medium ($10), and high value ($20) on each treatment day, and their movement time in pushing the joystick was measured over the course of 4 visits during the following conditions: Visit 1: Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2: After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3: 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4: After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa). Results reflect participants' response to the low incentive.

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• Joystick Movement Task - Experiment 1 - Medium Incentive

  All participants were tasked with pushing a joystick with the hand most affected by PD symptoms in response to monetary incentives. Participants were presented with incentives of low ($5), medium ($10), and high value ($20) on each treatment day, and their movement time in pushing the joystick was measured over the course of 4 visits during the following conditions: Visit 1: Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2: After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3: 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4: After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa). Results reflect participants' response to the medium incentive.

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• Joystick Movement Task - Experiment 1 - High Incentive

  All participants were tasked with pushing a joystick with the hand most affected by PD symptoms in response to monetary incentives. Participants were presented with incentives of low ($5), medium ($10), and high value ($20) on each treatment day, and their movement time in pushing the joystick was measured over the course of 4 visits during the following conditions: Visit 1: Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2: After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3: 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4: After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa). Results reflect participants' response to the high incentive.

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• Grip Force Task - Experiment 1 - Low Incentive

  Participants were tasked with modulating their grip strength in response to monetary incentives. With the hand most affected by PD symptoms, participants squeezed a dynamometer. Participants were presented with incentives of low ($5), medium ($10), and high value ($20) on each treatment day, and their time in reaching their maximum grip strength was measured over the course of 4 visits during the following conditions: Visit 1. Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2. After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3. 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4. After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa).

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• Grip Force Task - Experiment 1 - Medium Incentive

  Participants were tasked with modulating their grip strength in response to monetary incentives. With the hand most affected by PD symptoms, participants squeezed a dynamometer. Participants were presented with incentives of low ($5), medium ($10), and high value ($20) on each treatment day, and their time in reaching their maximum grip strength was measured over the course of 4 visits during the following conditions: Visit 1. Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2. After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3. 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4. After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa).

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• Grip Force Task - Experiment 1 - High Incentive

  Participants were tasked with modulating their grip strength in response to monetary incentives. With the hand most affected by PD symptoms, participants squeezed a dynamometer. Participants were presented with incentives of low ($5), medium ($10), and high value ($20) on each treatment day, and their time in reaching their maximum grip strength was measured over the course of 4 visits during the following conditions: Visit 1. Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2. After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3. 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4. After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa).

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

• MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS): Part III - Experiment 1

  Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS): Part III, Motor Examination. Scores range from 0 to 86. A higher score indicates worse motor performance. Participants completed this scale at each visit over the course of 4 visits during the following conditions: Visit 1. Baseline prior to chronic treatment initiation (Treatment Naïve Subject); Visit 2. After the initial, standard, acute oral dosage (SDR: Treatment Naïve Subject After Acute LDopa); Visit 3. 2-4 months after start of chronic treatment following Visit 2, stable LDopa treatment (as prescribed by treating physicians), but with no LDopa for 10-12 hours prior to Visit 3 (LDR: Chronically Treated - "Practical Off" State); and Visit 4. After resuming participants' usual physician-prescribed LDopa dose (SDR + LDR: Chronically Treated - After Usual LDopa).

  Visit 1 at Baseline, Visit 2 up to 2 weeks after baseline, Visit 3 up to 2-4 months after baseline, and Visit 4 up to 4 months after baseline

Study Arms (2)

Experiment 1: Primary Outcomes (MDS-UPDRS, Joystick Task, Tapping Speed)

OTHER

Participants will undergo evaluation of the relationship between the LDR and movement vigor. All participants will undergo standard evaluation with standard clinical rating scales and three outcome measures: Tapping Speed Task; Joystick Movement Task; and completion of MDS-UPDRS. carbidopa/levodopa, as prescribed by treating physician: There will be 4 measurement states: at baseline prior to chronic treatment initiation (OFF-No LDR); at baseline after a standard, acute oral dose (25/250 carbidopa/L-dopa), referenced in the protocol, but prescribed and provided by their prescribing physician as standard of care initial dosage (ON-No LDR); 2 months after initiation of chronic, stable L-dopa treatment (amounts and sequences as prescribed by treating physicians) but with no L-dopa for 10-12 hours prior to evaluation (Practical OFF- LDR); and after resuming subjects' usual physician-prescribed L-dopa dose (ON-LDR).

Drug: carbidopa/levodopa, as prescribed by treating physician

Experiment 2: Primary Outcome (Value Driven Attentional Oculomotor Capture)

OTHER

Participants will undergo evaluation of the relationship between the LDR and movement vigor. All participants will undergo standard evaluation with standard clinical rating scales and the outcome measure: Grip Strength Task - Measurement of Incentive-Outcome Coupling - Movement Vigor. carbidopa/levodopa, as prescribed by treating physician: There will be 4 measurement states: at baseline prior to chronic treatment initiation (OFF-No LDR); at baseline after a standard, acute oral dose (25/250 carbidopa/L-dopa), referenced in the protocol, but prescribed and provided by their prescribing physician as standard of care initial dosage (ON-No LDR); 2 months after initiation of chronic, stable L-dopa treatment (amounts and sequences as prescribed by treating physicians) but with no L-dopa for 10-12 hours prior to evaluation (Practical OFF- LDR); and after resuming subjects' usual physician-prescribed L-dopa dose (ON-LDR).

Drug: carbidopa/levodopa, as prescribed by treating physician

Interventions

carbidopa/levodopa, as prescribed by treating physician DRUG

There will be 4 measurement states: at baseline prior to chronic treatment initiation (OFF-No LDR); at baseline after a standard, acute oral dose (25/250 carbidopa/L-dopa), referenced in the protocol, but prescribed and provided by their prescribing physician as standard of care initial dosage (ON-No LDR); 2 months after initiation of chronic, stable L-dopa treatment (amounts and sequences as prescribed by treating physicians) but with no L-dopa for 10-12 hours prior to evaluation (Practical OFF- LDR); and after resuming subjects' usual physician-prescribed L-dopa dose (ON-LDR).

Also known as: Parcopa, Sinemet

Experiment 1: Primary Outcomes (MDS-UPDRS, Joystick Task, Tapping Speed); Experiment 2: Primary Outcome (Value Driven Attentional Oculomotor Capture)

Eligibility Criteria

• Age: 45 Years - 90 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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)

You may not qualify if:

• The presence of other neurologic disease or findings on examination
• Depression: Geriatric Depression Scale score \>11
• Use of dopamine agonists or stimulants
• Evidence of a stroke or mass lesion on prior structural brain imaging (MRI or CT)
• 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.

Sponsors & Collaborators

• University of Michigan: lead
• National Institute of Neurological Disorders and Stroke (NINDS): collaborator

Study Sites (1)

University of Michigan

Ann Arbor, Michigan, 48109, United States

Location

MeSH Terms

Conditions

Parkinson Disease

Interventions

Carbidopa; Levodopa; carbidopa, levodopa drug combination

Condition Hierarchy (Ancestors)

Parkinsonian Disorders; Basal Ganglia Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Movement Disorders; Synucleinopathies; Neurodegenerative Diseases

Intervention Hierarchy (Ancestors)

Methyldopa; Dihydroxyphenylalanine; Catecholamines; Amines; Organic Chemicals; Hydrazines; Catechols; Phenols; Benzene Derivatives; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons; Phenylalanine; Amino Acids, Aromatic; Amino Acids, Cyclic; Amino Acids; Amino Acids, Peptides, and Proteins; Tyrosine

Results Point of Contact

• Title: Dr. Roger Albin
• Organization: University of Michigan

ralbin@med.umich.edu

734-936-9115

Study Officials

• Roger Albin

  University of Michigan

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Neurology

Study Record Dates

• First Submitted: March 10, 2021
• First Posted: March 30, 2021
• Study Start: February 12, 2020
• Primary Completion: April 25, 2024
• Study Completion: April 25, 2024
• Last Updated: July 18, 2025
• Results First Posted: July 18, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)