Phase 2 N=5 Basic Science

Neurobiological Drivers of Mobility Resilience: The Dopaminergic System - Supplemental Open-Label Arm

Parkinsonian Signs in Older Persons

Bottom Line

View on ClinicalTrials.gov: NCT06587217 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Apr 2026

Primary outcome: Primary: Average Gait Speed — 0.81; 0.86; 0.86 meters per second

Study Design & Population

Study type: Interventional
Phase: Phase 2
Interventions: Carbidopa 25 mg (Drug); Carbidopa-Levodopa 25/100 mg (Drug)
Age: Adult, Older Adult · 60+ yrs
Sex: All
Sponsor: University of Michigan
Primary completion: Apr 2025

Outcome Measures

Outcome	Result	p-value
PRIMARY Average Gait Speed	0.81; 0.86; 0.86	—

Summary

Walking with age becomes both slower and less 'automated', requiring more attention and brain resources. As a result, older adults have a greater risk of negative outcomes and falls. There is an urgent need to identify factors that can help compensate for these harmful factors and reduce walking impairments, as there are currently no effective treatments available. Investigators have recently discovered that ~20% of older adults maintain fast walking speed even in the presence of small blood vessel brain changes and leg problems, thus appearing to be protected against these harmful factors. The investigators work suggests that the brain dopamine (DA) system may be a source of this protective capacity. Investigators have also shown that lower levels of dopamine are associated with slow walking. Investigators will be investigating the role of dopamine on slow walking and other parkinsonian signs in this open-label study using detailed clinical assessment, assessment of dopamine activity, and clinical interventions.

Eligibility Criteria

Inclusion Criteria

Age 60 or older (M/F)
Evidence of mild parkinsonian signs (incl. slow gait (<1m/s))

Exclusion Criteria

Evidence of prior established diagnosis and/or treatment for PD.
Presence of clinically significant degenerative joint disease and/or neuropathy interfering with proper assessment of the motor exam.
Presence of significant dementia.
History of stroke with residual clinical deficit interfering with walking.
For optional MR imaging only: Participants in whom magnetic resonance imaging (MRI) is contraindicated including, but not limited to, those with a pacemaker, presence of metallic fragments near the eyes or spinal cord, or cochlear implant.
For optional brain imaging only: Severe claustrophobia precluding neuroimaging procedures.
Participants that have been on monoamine oxidase inhibitors (MAOIs) within 2 weeks prior to starting study.
Inability to stand or walk without an assistive device
Hypersensitivity to the carbidopa, levodopa, and tablet components.
History of myocardial infarction (MI) with residual arterial, nodal or ventricular arrhythmia
History of peptic ulcer
Chronic wide angle glaucoma
Narrow angle glaucoma
Major psychotic disorder
Severe cardiovascular or pulmonary disease, bronchial asthma, renal, hepatic or endocrine disease
Subjects on dopamine D2 receptor antagonists, dopamine depleting agents, and metoclopramide.
Any other medical history determined by investigators to preclude safe participation.

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT06587217). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.