Parkinson's Disease (PD)RBD ImpulseNCT07213219
PET-MRI of Reward System in Parkinson's Disease With RBD
A study testing PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging). in people with Parkinson's Disease (PD), run by University Hospital, Clermont-Ferrand at 3 sites in France.
Trial summary
Impulse control disorders (ICDs) are frequently observed in Parkinson's disease (PD) and can have a major functional impact on the quality of life of both the patient and their entourage. Read more about this study
- Who is it for?
- Ages 45 to 80 years
- Conditions the study is for
- Parkinson's Disease (PD)
- What is being tested?
- PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging).
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 44 participants
- Where
- 3 sitesFrance
- Study dates
- 7 May 2026to 1 Jan 2029
- Phase
- Interventional
- 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 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients aged 45 to 80 years
- Patients diagnosed with idiopathic Parkinson's disease (PD) according to the Movement Disorder Society criteria
- Duration of Parkinson's disease progression ≥ 3 years
- Patients receiving chronic dopaminergic treatment including levodopa for at least one year to avoid tolerance issues during acute levodopa administration
- Ability to cooperate and understand, allowing strict compliance with the conditions set forth in the protocol
- Patients affiliated with or beneficiaries of a social security system
- Volunteer patients capable of providing informed consent to participate in the research
Who cannot join
- Patients suffering from neurological disorders other than idiopathic Parkinson's disease (PD)
- Patients with severe depression (Beck Depression Inventory \[20] (BDI) score > 30), apathy (Starkstein scale \[21] score ≥ 14), cognitive impairment (Montreal Cognitive Assessment \[MoCA] \[22] score < 25).
- Patients with impulse control disorders, defined by either of the following:
- A score of ≥ 6 on the "Pathological Gambling" item, ≥ 8 on the "Compulsive Buying" item, ≥ 8 on the "Sexual Behavior" item, or ≥ 7 on the "Eating Behavior" item, and more than one positive response (score > 0) on the corresponding QUIP-RS items for Gambling, Compulsive Buying, Sexual Behavior, and Eating Behavior.
- A total QUIP-RS score ≥ 10.
- Patients with severe motor symptoms: patients with an MDS-UPDRS III score > 45 will be excluded to avoid severe discomfort or interfering tremor (tremor item ≥ 3 in any body part) in the OFF state during PET-MRI acquisition. Patients with severe dyskinesias will also be excluded due to technical issues related to movement
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- Patients under guardianship, curatorship, deprived of liberty, or under legal protection
- Pregnant or breastfeeding women
- Patients with contraindications to PET-MRI (e.g., those with pacemakers or insulin pumps, metallic prostheses or intracerebral clips, claustrophobia, neurosensorial stimulators or implantable defibrillators, cochlear implants, ferromagnetic ocular or cerebral foreign bodies near nervous structures, uncooperative or agitated patients, neurosurgical ventriculoperitoneal shunts, dental appliances)
- Refusal to participate
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
France3 sites, 3 recruiting
- Recruiting
CHU Clermont-Ferrand, Clermont-Ferrand,
Clermont-Ferrand, 63000
Lise LACLAUTRE, +33473754963, promo_interne_drci@chu-clermontferrand.fr
Charlotte BEAL
- Recruiting
CH Le Puy en Velay
Le Puy-en-Velay
Jeremy DASSA
- Recruiting
CHRU Lyon
Lyon
Stéphane THOBOIS
About this study
Official title: Exploration of the Reward System in Parkinson's Patients With Paradoxical Sleep Behavior Disorders: a Multimodal Imaging Study
Impulse control disorders (ICDs) are frequently observed in Parkinson's disease (PD) and can have a major functional impact on the quality of life of both the patient and their entourage. The primary risk factor for the emergence of ICDs in PD is long-term dopaminergic treatment, but other risk factors, such as rapid eye movement sleep behavior disorder (RBD), have recently been identified. The mechanisms leading to ICDs in PD remain debated, but it has been shown that the dopaminergic mesocorticolimbic pathways play a key role in reward, learning, and reinforcement processes, as well as in the regulation of impulsivity. PET studies using [11C]raclopride, a tracer that allows evaluation of the postsynaptic availability of dopamine D2/D3 receptors, have demonstrated abnormal sensitization of the mesocorticolimbic dopaminergic system (the reward system), particularly in the ventral striatum, in Parkinson's patients with ICDs when presented with appetitive stimuli or during gambling tasks. However, this has never been studied in patients with and without RBD. Parkinson's patients with RBD may present greater impairment of mesocorticolimbic pathways than those without RBD, particularly abnormal sensitization and postsynaptic modifications of the dopaminergic system, which could predispose patients to the emergence of ICDs when exposed to dopaminergic agonists. Confirming a particular pattern of denervation in Parkinson's patients with RBD that may favor the emergence of ICDs constitutes a personalized medicine approach with a readily identifiable risk marker in routine clinical practice and offers the possibility of adapting the management of these patients.
The main objective of this study is to investigate the availability of D2 dopaminergic receptors in subcortical structures (particularly the mesocorticolimbic system) in patients with idiopathic Parkinson's disease, depending on the presence or absence of RBD
- Conditions
- Parkinson's Disease (PD)
- Being tested
- PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging).
- Keywords
- Impulse Control Disorders, Rapid Eye Movement Sleep Behavior Disorder, Parkinson&#39;s Disease, Positron Emission Tomography, [¹¹C]raclopride, Magnetic Resonance Imaging
- Medical subject headings
- Disruptive, Impulse Control, and Conduct Disorders, REM Sleep Behavior Disorder
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging).Other
The PET-MRI will be performed using a Siemens Biograph mMR hybrid PET-MRI scanner. A 60-minute dynamic PET acquisition will begin following the intravenous injection of \[¹¹C]raclopride (a radiotracer agonist of dopamine D2/D3 receptors) synthesized in the radiopharmaceutical laboratories of CERMEP. Simultaneously with the PET acquisition, brain MRI sequences will be acquired: 3D anatomical T1 and 3D T2, SWI, diffusion MRI (DTI), resting-state functional MRI, and arterial spin labeling (ASL) perfusion MRI.
Patients will undergo two PET-MRI scans on two consecutive days under two pharmacological conditions: Off and On dopamine:
- Day 1:** The first PET-MRI session (TEPDopaOff) will be performed after a 12-hour withdrawal from usual dopaminergic treatment (Off dopamine).
- Day 2:** The second PET-MRI session (TEPDopaOn) will be similar to the first, except it will take place 1 hour after administration of immediate-release Levodopa
| Study group | Role | What they receive |
|---|---|---|
| MPI with RBD | Experimental | Not described Receives: Other: PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging). |
| MPI without RBD | Experimental | control group Receives: Other: PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging). |
What is being measured
The primary outcome is the main question the study is designed to answer.
[¹¹C]raclopride binding potential (BP, unitless) measured with PET-MRI in mesocorticolimbic brain structures between participants with and without RBD, off treatment.
The primary outcome measure corresponds to the Difference in binding potential (BP) of [¹¹C]raclopride in the brain structures of the mesocorticolimbic network between groups with and without RBD at baseline evaluation, off treatment, derived from PET-MRI imaging in mesocorticolimbic brain structures.
The measurement tool is the [¹¹C]raclopride PET-MRI. BP is a unitless quantitative parameter (ratio between specifically bound radioligand and non-displaceable radioligand in tissue).
Measured: During MRI exploration (3 months after inclusion visit)
Secondary outcomes (8)
[¹¹C]raclopride binding potential (BP, unitless) measured with PET-MRI in mesocorticolimbic brain structures between participants with and without RBD following acute administration of Levodopa
Measured: During MRI exploration (3 months after inclusion visit)
MDS-UPDRS III motor score
UPPS impulsivity scale score
Measured: at the inclusion visit
Starkstein apathy scale score
Measured: at inclusion visit
BDI depression score
Measured: at inclusion visit
Ardouin Scale of Behavior in Parkinson's Disease) scores (hypodopaminergic and hyperdopaminergic items)
Measured: at inclusion visit
Total levodopa equivalent dose and for agonists (in mg/day)
Measured: at inclusion visit
Voxel-wise parametric statistical maps (SPM) across the whole brain comparing PET parametric images ([¹¹C]raclopride BP)
Measured: During MRI exploration (3 months after inclusion visit)
Voxel-wise parametric statistical maps (SPM) across the whole brain comparing MRI images.
Measured: During MRI exploration (3 months after inclusion visit)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Oct 2025
- Study start7 May 2026
- Primary completion1 Jan 2028 (estimated)
- Study completion1 Jan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Parkinson's Disease (PD)Studies of the same condition, open and under way.
- More trials run by University Hospital, Clermont-FerrandThe 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- Exploratory cross-sectional comparative study of pathophysiology. 2 groups will be compared : * MPI with RBD * MPI without RBD (control group)
- Masking
- None (open label)
- Enrolment
- 44 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital, Clermont-Ferrand
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Charlotte BEAL, Principal investigator, University Hospital, Clermont-Ferrand
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07213219
- Sponsor's protocol ID
- PHRC I 2022 BEAL
- Other IDs
- 2024-A00544-43
- Acronym
- RBD Impulse
- Status last verified
- Oct 2025
- First submitted
- 22 Sep 2025
- Last updated
- 8 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Exploration of the Reward System in Parkinson's Patients With Paradoxical Sleep Behavior Disorders: a Multimodal Imaging Study
- ClinicalTrials.gov ID
- NCT07213219
- Acronym / sponsor ID
- RBD Impulse / PHRC I 2022 BEAL
- Conditions
- Parkinson's Disease (PD)
- Keywords
- Impulse Control Disorders, Rapid Eye Movement Sleep Behavior Disorder, Parkinson&#39;s Disease, Positron Emission Tomography, [¹¹C]raclopride, Magnetic Resonance Imaging
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 44 participants (estimated)
- Lead sponsor
- University Hospital, Clermont-FerrandUniversity, hospital or other
- Study start
- 7 May 2026 (actual)
- Primary completion
- 1 Jan 2028 (estimated)
- Study completion
- 1 Jan 2029 (estimated)
- First posted
- 8 Oct 2025 (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.
Impulse control disorders (ICDs) are frequently observed in Parkinson's disease (PD) and can have a major functional impact on the quality of life of both the patient and their entourage. The primary risk factor for the emergence of ICDs in PD is long-term dopaminergic treatment, but other risk factors, such as rapid eye movement sleep behavior disorder (RBD), have recently been identified. The mechanisms leading to ICDs in PD remain debated, but it has been shown that the dopaminergic mesocorticolimbic pathways play a key role in reward, learning, and reinforcement processes, as well as in the regulation of impulsivity. PET studies using [11C]raclopride, a tracer that allows evaluation of the postsynaptic availability of dopamine D2/D3 receptors, have demonstrated abnormal sensitization of the mesocorticolimbic dopaminergic system (the reward system), particularly in the ventral striatum, in Parkinson's patients with ICDs when presented with appetitive stimuli or during gambling tasks. However, this has never been studied in patients with and without RBD. Parkinson's patients with RBD may present greater impairment of mesocorticolimbic pathways than those without RBD, particularly abnormal sensitization and postsynaptic modifications of the dopaminergic system, which could predispose patients to the emergence of ICDs when exposed to dopaminergic agonists. Confirming a particular pattern of denervation in Parkinson's patients with RBD that may favor the emergence of ICDs constitutes a personalized medicine approach with a readily identifiable risk marker in routine clinical practice and offers the possibility of adapting the management of these patients.
The main objective of this study is to investigate the availability of D2 dopaminergic receptors in subcortical structures (particularly the mesocorticolimbic system) in patients with idiopathic Parkinson's disease, depending on the presence or absence of RBD
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Exploratory cross-sectional comparative study of pathophysiology. 2 groups will be compared : * MPI with RBD * MPI without RBD (control group)
| Arm | Type | Receives |
|---|---|---|
| MPI with RBD | Experimental | Other: PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging). |
| MPI without RBD | Experimental | Other: PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging).control group |
Who may qualify
- Ages
- 45 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Patients aged 45 to 80 years
- Patients diagnosed with idiopathic Parkinson's disease (PD) according to the Movement Disorder Society criteria
- Duration of Parkinson's disease progression ≥ 3 years
- Patients receiving chronic dopaminergic treatment including levodopa for at least one year to avoid tolerance issues during acute levodopa administration
- Ability to cooperate and understand, allowing strict compliance with the conditions set forth in the protocol
Key exclusion criteria (10 listed)
- Patients suffering from neurological disorders other than idiopathic Parkinson's disease (PD)
- Patients with severe depression (Beck Depression Inventory \[20] (BDI) score > 30), apathy (Starkstein scale \[21] score ≥ 14), cognitive impairment (Montreal Cognitive Assessment \[MoCA] \[22] score < 25).
- Patients with impulse control disorders, defined by either of the following:
- Patients with severe motor symptoms: patients with an MDS-UPDRS III score > 45 will be excluded to avoid severe discomfort or interfering tremor (tremor item ≥ 3 in any body part) in the OFF state during PET-MRI acquisition. Patients with severe dyskinesias will also be excluded due to technical issues related to movement
- Patients under guardianship, curatorship, deprived of liberty, or under legal protection
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging).The PET-MRI will be performed using a Siemens Biograph mMR hybrid PET-MRI scanner. A 60-minute dynamic PET acquisition will begin following the intravenous injection of \[¹¹C]raclopride (a radiotracer agonist of dopamine D2/D3 receptors) synthesized in the radiopharmaceutical laboratories of CERMEP. Simultaneously with the PET acquisition, brain MRI sequences will be acquired: 3D anatomical T1 and 3D T2, SWI, diffusion MRI (DTI), resting-state functional MRI, and arterial spin labeling (ASL) perfusion MRI. Patients will undergo two PET-MRI scans on two consecutive days under two pharmacological conditions: Off and On dopamine: * Day 1:** The first PET-MRI session (TEPDopaOff) will be performed after a 12-hour withdrawal from usual dopaminergic treatment (Off dopamine). * Day 2:** The second PET-MRI session (TEPDopaOn) will be similar to the first, except it will take place 1 hour after administration of immediate-release Levodopa | Other | MPI with RBD, MPI without RBD |
Primary outcome
[¹¹C]raclopride binding potential (BP, unitless) measured with PET-MRI in mesocorticolimbic brain structures between participants with and without RBD, off treatment.
Time frame: During MRI exploration (3 months after inclusion visit)
The primary outcome measure corresponds to the Difference in binding potential (BP) of [¹¹C]raclopride in the brain structures of the mesocorticolimbic network between groups with and without RBD at baseline evaluation, off treatment, derived from PET-MRI imaging in mesocorticolimbic brain structures. The measurement tool is the [¹¹C]raclopride PET-MRI. BP is a unitless quantitative parameter (ratio between specifically bound radioligand and non-displaceable radioligand in tissue).
8 secondary outcomes
[¹¹C]raclopride binding potential (BP, unitless) measured with PET-MRI in mesocorticolimbic brain structures between participants with and without RBD following acute administration of Levodopa
Time frame: During MRI exploration (3 months after inclusion visit)
MDS-UPDRS III motor score
Time frame: at the inclusion visit
Starkstein apathy scale score
Time frame: at inclusion visit
BDI depression score
Time frame: at inclusion visit
Ardouin Scale of Behavior in Parkinson's Disease) scores (hypodopaminergic and hyperdopaminergic items)
Time frame: at inclusion visit
Total levodopa equivalent dose and for agonists (in mg/day)
Time frame: at inclusion visit
Voxel-wise parametric statistical maps (SPM) across the whole brain comparing PET parametric images ([¹¹C]raclopride BP)
Time frame: During MRI exploration (3 months after inclusion visit)
Voxel-wise parametric statistical maps (SPM) across the whole brain comparing MRI images.
Time frame: During MRI exploration (3 months after inclusion visit)
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 8 Jul 2026.
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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.
Charlotte BEAL principal investigator
University Hospital, Clermont-Ferrand
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing PET-MRI (Positron Emission Tomography - Magnetic Resonance Imaging). in people with Parkinson's Disease (PD), run by University Hospital, Clermont-Ferrand at 3 sites in France.
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 7 inclusion and 10 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 8 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in France. 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 Lise LACLAUTRE (+334.73.754.963, promo_interne_drci@chu-clermontferrand.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
[¹¹C]raclopride binding potential (BP, unitless) measured with PET-MRI in mesocorticolimbic brain structures between participants with and without RBD, off treatment. (time frame: During MRI exploration (3 months after inclusion visit)). 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 8 Jul 2026.