Pain Assessment in Patients With Idiopathic Rapid Eye Movement (REM) Sleep Behaviour Disorder (PAIN-iRBD)

Pain Assessment in Patients With Idiopathic REM Sleep Behaviour Disorder

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease, with over 12 million patients expected globally by 2040. The disease is currently diagnosed at the appearance of motor symptoms, but by then, over 60% of striatal dopaminergic neurons have already been destroyed. Prodromal symptoms such as idiopathic REM Sleep Behavior Disorder (iRBD), anosmia, mood disorders and constipation appear earlier and are listed as criteria for a prodromal PD diagnosis. Identifying early signs is critical to initiate neuroprotective treatments as early as possible. While pain is prevalent and highly disabling in early PD, no data are currently available on pain perception in iRBD patients, whose condition is of the main risk factor for PD development.

Study Overview

• Status: Recruiting
• Conditions: Narcolepsy Type 1; REM Sleep Behavior Disorder (iRBD)
• Intervention / Treatment: Other: Thermo test pain; Other: Pain questionnaires; Other: No motors symptoms evaluations

• Study Type: Interventional
• Enrollment (Estimated): 24
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Christine BREFEL COURBON; Phone Number: +33 05 61 77 60 39; Email: christine.brefel-courbon@univ-tlse3.Fr

Study Locations

• France
  • Toulouse, France, 31059
    • Recruiting
    • Centre Expert Parkinson Hôpital Pierre Paul Riquet Place du Docteur Baylac
    • Contact: Emeline Muller; Phone Number: +33 05 61 77 87 07; Email: muller.E@chu-toulouse.Fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion criteria:

• Diagnosed with iRBD confirmed by polysomnography;
• No clinical diagnosis of Parkinson's disease or other diagnosis of neurodegenerative disease;
• Ability to understand and complete study procedures and questionnaires;

Control group:

• Diagnosed with narcolepsy type 1;
• Coexisting REM sleep behavior disorder confirmed by polysomnography;
• Ability to understand and complete study procedures and questionnaires;

Exclusion Criteria:

• Diagnosed Parkinson's Disease, dementia with Lewy bodies or multiple system atrophy;
• Severe depression according to Diagnostic and Statistical Manual of Mental Disorders (DSM V);
• Inability to complete study procedures or questionnaires.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Idiopathic REM sleep Behavior disorder (iRBD) Group; Patients who have an idiopathic REM sleep Behavior Disorder	Other: Thermo test pain; Patients will undergo a pain test, also called a thermotest, which consists of determining pain thresholds using a thermometer applied to the hand.; Other: Pain questionnaires; Patients will complete various questionnaires about pain; Other: No motors symptoms evaluations; Patients will complete questionnaires
Active Comparator: Idiopathic REM Sleep Bhavior Disorder (iRBD) + narcolepsy type 1; patients who have an iRBD and who have type 1 narcolepsy	Other: Thermo test pain; Patients will undergo a pain test, also called a thermotest, which consists of determining pain thresholds using a thermometer applied to the hand.; Other: Pain questionnaires; Patients will complete various questionnaires about pain; Other: No motors symptoms evaluations; Patients will complete questionnaires

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison of the intensity of chronic pain between patients with iRBD and a control group of patients	Measuring the Visual Analog Scale (VAS) between patients with iRBD without diagnosis of PD and a control group of patients diagnosed with narcolepsy type 1 who present RBD (Rapid eye movement sleep behavior disorder).	2 hours after the inclusion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Describe semiological characteristics of pain in RBD patients	Description of characteristics of pain	2 hours after the inclusion
Compare the presence of chronic pain	Number of patients with chronic pain in both groups for at least 3 months.	2 hours after the inclusion
Assessing Pain Characteristics	Score obtained on pain questionnaires	2 hours after the inclusion
Assessment of thermal pain threshold and tolerance	Results of the quantitative sensory test (thermal thermotest) in both groups	2 hours after the inclusion
Assessment of correlations between the intensity of chronic pain	Correlation between Visual Analogue Scale (VAS) measurements and questionnaire responses	2 hours after the inclusion

Collaborators and Investigators

• Sponsor: University Hospital, Toulouse

Study record dates

Study Major Dates

• Study Start (Actual): February 24, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026

Study Registration Dates

• First Submitted: January 16, 2026
• First Submitted That Met QC Criteria: January 16, 2026
• First Posted (Actual): January 26, 2026

Study Record Updates

• Last Update Posted (Actual): May 1, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: pain; sleep; REM sleep; parkinson; REM sleep behavior disorder; narcolepsy Type 1
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Sleep Wake Disorders; Parasomnias; REM Sleep Parasomnias; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; REM Sleep Behavior Disorder
• Other Study ID Numbers: RC31/25/0567; ID-RCB (Other Identifier: 2026-A00289-42)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No