Parkinson DiseaseLRRK2NCT07642908
Striatal and Extra-Striatal Cholinergic Terminal Density in LRRK2-PD Mutation
An observational study of Parkinson Disease, run by University of Michigan at 1 site in United States.
Trial summary
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). Read more about this study
- Who is it for?
- Ages 45 years and older
- Conditions the study is for
- Parkinson Disease
- How many people
- 15 participants
- Where
- 1 siteUnited States
- Study dates
- 18 Sep 2025to 17 Sep 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 45 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Individuals with Parkinson's disease and the LRRK2 genetic mutation.
Who may be able to join
- 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.
Who cannot join
- 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.
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- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Michigan
Ann Arbor, Michigan, 48106
Nathan Alexander, BSc, 734-998-6894, natealex@med.umich.edu
Gerianne Que, BSc, 734-998-4790, queg@med.umich.edu
About this study
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.
Read the detailed description
LRRK2 mutations are among the most common genetic risk factors for Parkinson's Disease (PD), accounting for ~1% to 36% of familial cases depending on the ancestry, and a significant fraction of sporadic cases. These mutations are not fully penetrant, with 17-85% of carriers eventually developing PD. Among LRRK2-PD patients, clinical features manifest differently compared to idiopathic PD (iPD). LRRK2-PD patients often experience milder progression, with fewer non-motor symptoms and relatively preserved cognition, but higher likelihood of postural instability and gait difficulties (PIGD). This complex profile likely reflects the pleiotropic nature of LRRK2 effects, with mutations causing pathological increases in kinase activity and hyperphosphorylation of downstream targets. A comprehensive understanding of the protective and harmful changes induced by LRRK2 mutations remains a significant research gap.
While PD has traditionally been viewed as primarily a dopaminergic disorder, it is increasingly recognized as a multi-system condition involving other neuromodulatory systems, particularly cholinergic systems. Loss of cholinergic systems integrity is linked to dopamine-refractory symptoms, including morbid gait and cognitive impairments. Recent studies, however, demonstrate that subsets of both newly diagnosed and established PD patients exhibit upregulation of the vesicular acetylcholine transporter (VAChT), associated with preserved cognitive function, in both cross-sectional and longitudinal analyses.
A comprehensive, whole-brain investigation using the specific 18F-fluoroethoxybenzovesamicol ([18F]FEOBV) radioligand will help us better understand the nuanced whole-brain system changes in cholinergic nerve terminal integrity in LRRK2-PD compared to iPD. Our primary recruitment efforts will focus on the University of Michigan's Movement Disorder clinics, allowing us to connect with individuals diagnosed with PD who have the LRRK2 mutation. Additionally, we will work closely with PDGENEration and their sites such as Cleveland and Columbus. This collaboration will provide access to a larger pool of individuals with LRRK2 mutations, improving our ability to recruit participants for our study and ensuring a thorough investigation. We will identify regional cholinergic system alterations in PD with LRRK2 mutations. This would facilitate research on understanding the pathogenic basis for cholinergic activity alterations in iPD as well. Cholinergic systems offer multiple potential targets for pharmacologic and non-invasive neurostimulation interventions. Identification of distinctive cholinergic systems abnormalities in LRRK2-PD would provide new targets for potential therapies, initiating new approaches to experimental therapeutics in PD with LRRK2 mutations and informed by novel insights into PD pathomechanisms.
Aim 1a: To assess in vivo comprehensive, whole-brain expression and activity of cholinergic nerve terminals of LRRK2-PD patients relative to iPD patients using the [18F]FEOBV vesicular acetylcholine transporter (VAChT) radioligand.
Aim 1b: To correlate in vivo striatal and extra-striatal [18F]FEOBV regional binding with cognitive and motor assessments (esp. PIGD symptoms) in LRRK2-PD and iPD.
Aim 2a: To examine differences in striatal and extra-striatal dopamine terminal density between LRRK2-PD and iPD using the complementary PET tracer N-(3-iodoprop-2E-enyl)-2β-carbomethoxy-3β-(4-methyl-phenyl)nortropane ([¹¹C]PE2i).
Aim 2b: To investigate the association between dopaminergic function, cognition, and PIGD symptoms
- Conditions
- Parkinson Disease
- Keywords
- Parkinson's Disease, LRRK, LRRK2, functional neuroimaging
- Medical subject headings
- Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| LRRK2 | Individuals with PD and LRRK2 genetic mutation. | |
| iPD | Individuals with PD and without LRRK2 genetic mutation (Pre-existing cohorts, not recruiting). |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cholinergic Differences Between leucine-rich repeat kinase 2 (LRRK2) Parkinson's disease (PD) and Idiopathic/non-LRRK2 PD (iPD)
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.
Measured: Baseline
Dopaminergic Differences Between LRRK2-PD and iPD
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.
Measured: Baseline
Association of Cholinergic Data With Cognition in LRRK2-PD
Association of the global average cholinergic uptake (represented by VAChT uptake) with the global average cognitive z-score of individuals with LRRK2-PD.
Measured: Baseline
Association of Cholinergic Data With Postural Instability and Gait Difficulties (PIGD) in LRRK2-PD
Association of the global average cholinergic uptake (represented by VAChT uptake) with the global average PIGD score of individuals with LRRK2-PD.
Measured: Baseline
Association of Dopaminergic Data With Cognition in LRRK2-PD
Association of the global average dopaminergic uptake (represented by DAT uptake) with the global average cognitive z-score of individuals with LRRK2-PD.
Measured: Baseline
Association of Dopaminergic Data With PIGD in LRRK2-PD
Association of the global average dopaminergic uptake (represented by DAT uptake) with the global average PIGD score of individuals with LRRK2-PD.
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2026
- Study start18 Sep 2025
- Primary completion17 Sep 2026 (estimated)
- Study completion17 Sep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Parkinson DiseaseStudies of the same condition, open and under way.
- More trials run by University of MichiganThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Michigan
- Sponsor type
- University, hospital or other
- Collaborators
- Michael J. Fox Foundation for Parkinson's Research
- Responsible party
- Principal investigator, Prabesh Kanel, University of Michigan
- Investigators
- Prabesh Kanel, PhD, Principal investigator, University of Michigan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07642908
- Sponsor's protocol ID
- HUM00276006
- Acronym
- LRRK2
- Status last verified
- Jun 2026
- First submitted
- 13 May 2026
- Last updated
- 11 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data (imaging data, clinical assessments, and neuropsychological test results) may be shared with other researchers. Data will be shared with the study sponsor (Michael J. Fox Foundation) for the purposes of contributing to Parkinson's Progression Markers Initiative (PPMI) repository. Data will be available through PPMI on a case-by-case basis upon reasonable request after the completion of the study.
Study at a glance
From the registry record, last updated by the sponsor on 11 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Striatal and Extra-Striatal Cholinergic Terminal Density in LRRK2-PD Mutation
- ClinicalTrials.gov ID
- NCT07642908
- Acronym / sponsor ID
- LRRK2 / HUM00276006
- Conditions
- Parkinson Disease
- Keywords
- Parkinson's Disease, LRRK, LRRK2, functional neuroimaging
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- University of MichiganUniversity, hospital or other
- Collaborators
- Michael J. Fox Foundation for Parkinson's Research
- Study start
- 18 Sep 2025 (actual)
- Primary completion
- 17 Sep 2026 (estimated)
- Study completion
- 17 Sep 2026 (estimated)
- First posted
- 11 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
LRRK2 mutations are among the most common genetic risk factors for Parkinson's Disease (PD), accounting for ~1% to 36% of familial cases depending on the ancestry, and a significant fraction of sporadic cases. These mutations are not fully penetrant, with 17-85% of carriers eventually developing PD. Among LRRK2-PD patients, clinical features manifest differently compared to idiopathic PD (iPD). LRRK2-PD patients often experience milder progression, with fewer non-motor symptoms and relatively preserved cognition, but higher likelihood of postural instability and gait difficulties (PIGD). This complex profile likely reflects the pleiotropic nature of LRRK2 effects, with mutations causing pathological increases in kinase activity and hyperphosphorylation of downstream targets. A comprehensive understanding of the protective and harmful changes induced by LRRK2 mutations remains a significant research gap.
While PD has traditionally been viewed as primarily a dopaminergic disorder, it is increasingly recognized as a multi-system condition involving other neuromodulatory systems, particularly cholinergic systems. Loss of cholinergic systems integrity is linked to dopamine-refractory symptoms, including morbid gait and cognitive impairments. Recent studies, however, demonstrate that subsets of both newly diagnosed and established PD patients exhibit upregulation of the vesicular acetylcholine transporter (VAChT), associated with preserved cognitive function, in both cross-sectional and longitudinal analyses.
A comprehensive, whole-brain investigation using the specific 18F-fluoroethoxybenzovesamicol ([18F]FEOBV) radioligand will help us better understand the nuanced whole-brain system changes in cholinergic nerve terminal integrity in LRRK2-PD compared to iPD. Our primary recruitment efforts will focus on the University of Michigan's Movement Disorder clinics, allowing us to connect with individuals diagnosed with PD who have the LRRK2 mutation. Additionally, we will work closely with PDGENEration and their sites such as Cleveland and Columbus. This collaboration will provide access to a larger pool of individuals with LRRK2 mutations, improving our ability to recruit participants for our study and ensuring a thorough investigation. We will identify regional cholinergic system alterations in PD with LRRK2 mutations. This would facilitate research on understanding the pathogenic basis for cholinergic activity alterations in iPD as well. Cholinergic systems offer multiple potential targets for pharmacologic and non-invasive neurostimulation interventions. Identification of distinctive cholinergic systems abnormalities in LRRK2-PD would provide new targets for potential therapies, initiating new approaches to experimental therapeutics in PD with LRRK2 mutations and informed by novel insights into PD pathomechanisms.
Aim 1a: To assess in vivo comprehensive, whole-brain expression and activity of cholinergic nerve terminals of LRRK2-PD patients relative to iPD patients using the [18F]FEOBV vesicular acetylcholine transporter (VAChT) radioligand.
Aim 1b: To correlate in vivo striatal and extra-striatal [18F]FEOBV regional binding with cognitive and motor assessments (esp. PIGD symptoms) in LRRK2-PD and iPD.
Aim 2a: To examine differences in striatal and extra-striatal dopamine terminal density between LRRK2-PD and iPD using the complementary PET tracer N-(3-iodoprop-2E-enyl)-2β-carbomethoxy-3β-(4-methyl-phenyl)nortropane ([¹¹C]PE2i).
Aim 2b: To investigate the association between dopaminergic function, cognition, and PIGD symptoms
Study design
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| LRRK2 | – | –Individuals with PD and LRRK2 genetic mutation. |
| iPD | – | –Individuals with PD and without LRRK2 genetic mutation (Pre-existing cohorts, not recruiting). |
Who may qualify
- Ages
- 45 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Individuals with Parkinson's disease and the LRRK2 genetic mutation.
Key inclusion criteria (3 listed)
- 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.
Key exclusion criteria (9 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
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.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jun 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data (imaging data, clinical assessments, and neuropsychological test results) may be shared with other researchers. Data will be shared with the study sponsor (Michael J. Fox Foundation) for the purposes of contributing to Parkinson's Progression Markers Initiative (PPMI) repository. Data will be available through PPMI on a case-by-case basis upon reasonable request after the completion of the study.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Prabesh Kanel, PhD principal investigator
University of Michigan
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Parkinson Disease, run by University of Michigan at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Nathan Alexander, BSc (734-998-6894, natealex@med.umich.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cholinergic Differences Between leucine-rich repeat kinase 2 (LRRK2) Parkinson's disease (PD) and Idiopathic/non-LRRK2 PD (iPD) (time frame: Baseline). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Jun 2026.