Studying serotonin system and pain in people with Parkinson's disease
Uses brain scans to study serotonin in Parkinson's patients with and without pain.
Plain-language title generated from the registry record
Registry title: Pain in Parkinson's Disease: Exploration of the Serotonin System in Positron Emission Tomography (PET [18F]-MPPF)
Key facts
- Where
- Toulouse, FranceSee the site
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for people with Parkinson's disease, with and without long-lasting pain from the disease. Participants have a brain PET scan and an MRI.
- Age
- 40 to 80 years
- Sex
- All sexes can join.
- Disease stage
- Parkinson's disease by the UK Brain Bank criteria. One group has central pain from Parkinson's for at least 3 months, with average pain of 4 or more on a VAS. The other group has no pain, with a VAS of 4 or less.
- Earlier treatment
- Stable anti-parkinsonian treatment for at least 4 weeks before joining. No second-line therapy. No drugs that act on 5HT1A receptors in the previous 4 weeks.
- Biomarker or test result
- MoCA score above 25. HADS-D score of 11 or more.
Main reasons for not taking part
- Treated with second-line therapy
- History of significant psychiatric illness, in the investigator's view
- Treated with drugs that act on 5HT1A receptors in the previous 4 weeks
- Cannot have an MRI
- Pregnant or breastfeeding women
Read by machine on 12 November 2026.
Could this be for you?
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 40 and 80 years old?
Source: NCT06008704, who can take part
Where in France
- Centre Hospitalier Universitaire de ToulouseToulouse, FranceContact: Christine Brefel-Courbon, MD, PhDTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorTrial details
- Who runs it
- University Hospital, Toulouse
- Trial code
- NCT06008704
- Record updated
- 11 May 2026
- Original description
This project will explore the involvement of the serotonin system in the pathophysiology of PD-related central pain. Thus, the serotonin system will be evaluated in PD patients with and without central pain who will benefit from brain positron emission tomography (PET) allowing in vivo imaging of 5HT1A receptors and multimodal brain MRI including morphometric imaging and functional connectivity (resting state acquisition).Read full original descriptionShow less
Pathophysiology of Pain in Parkinson's Disease: Exploration of the Serotonin System in Positron Emission Tomography (PET [18F]-MPPF)
This project will explore the involvement of the serotonin system in the pathophysiology of PD-related central pain. Thus, the serotonin system will be evaluated in PD patients with and without central pain who will benefit from brain positron emission tomography (PET) allowing in vivo imaging of 5HT1A receptors and multimodal brain MRI including morphometric imaging and functional connectivity (resting state acquisition).
Inclusion: Patients with PD defined according to United Kingdom Parkinson's Disease Brain Bank (UKPDSBB) criteria; Patients with stable anti-parkinsonian treatment for at least 4 weeks prior to inclusion; Patients with a Montreal Cognitive Assessment (MoCA) score > 25; Patients with a Hospital Anxiety and Depression Scale (HADS)-D score ≥ 11; Person affiliated or benefiting from a social security scheme; Free, informed and written consent signed by the participant and the investigator (at the latest on the day of inclusion and before any examination required by the research); For patients with pain; Patients with PD-related central pain defined according to the criteria of Marques et al, 2019; Patients with chronic central pain (i.e. present for at least 3 months); Patients who have average pain over the previous month according to a VAS ≥ 4; For patients without pain; Patients who do not have pain defined as VAS ≤ 4, meaning that it does not interfere with daily activity.
Exclusion: Patients treated with second line therapy; Patients treated with drugs interacting with 5HT1A receptors in the previous 4 weeks; Patients with a history of significant psychiatric pathology according to the investigator; Patients with contraindication to MRI; Patients refusing to be informed of an abnormality discovered during brain imaging; Patients with dyskinesias judged by the investigator to be disabling for imaging; Patients under guardianship or other legal protection, deprived of their liberty by judicial or administrative decision; Pregnant woman, breastfeeding woman.