NCT07642908 · University of Michigan
Striatal and Extra-Striatal Cholinergic Terminal Density in LRRK2-PD Mutation
(LRRK2)
What this study is about
This study explores how a specific genetic mutation of leucine-rich repeat kinase 2 (LRRK2) affects individuals with Parkinson's disease (PD), comparing those with the mutation to others with Parkinson's disease and without the mutation (iPD).
View original scientific description
This study explores how a specific genetic mutation of leucine-rich repeat kinase 2 (LRRK2) affects individuals with Parkinson's disease (PD), comparing those with the mutation to others with Parkinson's disease and without the mutation (iPD). Participants will complete positron emission tomography (PET) and magnetic resonance imaging (MRI) brain imaging, cognitive tests, motor tests, sensory tests, and questionnaires. The aims of this study are to compare brain chemicals in LRRK2 PD patients with iPD patients and to correlate brain chemicals with motor and cognitive tests in LRRK2 PD and iPD patients.
Primary outcome measures
Cholinergic Differences Between leucine-rich repeat kinase 2 (LRRK2) Parkinson's disease (PD) and Idiopathic/non-LRRK2 PD (iPD)
Time frame: Baseline
The cholinergic system changes for people with PD. It is anticipated that LRRK2-PD will demonstrate different cholinergic expression compared to iPD. 18F-fluoroethoxybenzovesamicol (\[18F\]FEOBV) PET scans will be used to measure Vesicular acetylcholine transporter (VAChT). Higher levels of VAChT binding indicate higher levels of acetylcholine in the brain. Lower levels of VAChT binding indicate lower levels of acetylcholine in the brain. VAChT levels will be compared across brain regions for LRRK2 vs iPD.
Dopaminergic Differences Between LRRK2-PD and iPD
Time frame: Baseline
The dopaminergic system changes for people with PD. It is anticipated that LRRK2-PD will demonstrate different dopaminergic expression compared to iPD. N-(3-iodoprop-2E-enyl)-2β-carbomethoxy-3β-(4-methyl-phenyl)nortropane (\[¹¹C\]PE2i) PET scans will be used to measure dopamine transporter (DAT). Higher levels of DAT binding indicate higher levels of dopamine in the brain. Lower levels of DAT binding indicate lower levels of dopamine in the brain. DAT levels will be compared across brain regions for LRRK2 vs iPD.
Association of Cholinergic Data With Cognition in LRRK2-PD
Time frame: Baseline
Association of the global average cholinergic uptake (represented by VAChT uptake) with the global average cognitive z-score of individuals with LRRK2-PD.
Association of Cholinergic Data With Postural Instability and Gait Difficulties (PIGD) in LRRK2-PD
Time frame: Baseline
Association of the global average cholinergic uptake (represented by VAChT uptake) with the global average PIGD score of individuals with LRRK2-PD.
Association of Dopaminergic Data With Cognition in LRRK2-PD
Time frame: Baseline
Association of the global average dopaminergic uptake (represented by DAT uptake) with the global average cognitive z-score of individuals with LRRK2-PD.
Association of Dopaminergic Data With PIGD in LRRK2-PD
Time frame: Baseline
Association of the global average dopaminergic uptake (represented by DAT uptake) with the global average PIGD score of individuals with LRRK2-PD.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Male or Female, age 45 years and over.
- Diagnosis of PD based on the United Kingdom Parkinson's Disease Society Brain Bank Diagnostic Research Criteria (Hughes et al., 1992).
- Presence of LRRK2 mutation as confirmed by referral from UM Movement Disorders clinic, medical record review, or participation in the PDGENEration study.
Exclusion criteria
- Evidence of atypical parkinsonism.
- Contra-indications to MR imaging including but not limited to pacemakers, aneurysm clips, intraocular metal, cochlear implant, or severe claustrophobia.
- Evidence of large vessel stroke or mass lesion on MRI.
- Regular use of typical anti-cholinergic drugs or cholinesterase inhibitors.
- History of deep brain stimulation surgery.
- Pregnant or nursing.
- Suicidal ideation, as indicated by a response of 2 or 3 on question 9 of the Beck Depression Inventory.
- Cognitive impairment that results in the inability to give consent, as demonstrated by the Decision Making Capacity Tool.
- Any other condition or criterion that would preclude safe and meaningful participation in the study.
Where
- Ann Arbor, Michigan
Collaborators
Michael J. Fox Foundation for Parkinson's Research
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 11, 2026 · Source of record for eligibility and locations