Study of the Frequency and Characteristics of Pain Symptoms in Restless Legs Syndrome (PAIN-RLS)

Restless Legs Syndrome (RLS) is a neurological disorder affecting between 4% and 29% of adults. It is characterized by an urge to move the legs or other parts of the body, often accompanied by unpleasant and sometimes painful sensations. The pathophysiology of RLS, whether associated with pain or not, remains poorly understood, and only a limited number of studies have specifically investigated this aspect.

The aim of this study is to determine the prevalence of the painful component of symptoms in a large cohort of patients with RLS, to further characterize its clinical features, and to assess its impact on patients' quality of life. This work could improve the identification of patients experiencing pain, enhance our understanding of pain characteristics in RLS, and help optimize patient management. Furthermore, in the context of emerging therapeutic approaches such as neuromodulation, a better characterization of pain in RLS may contribute to the development and evaluation of new treatment strategies. This is particularly relevant given the high prevalence of RLS and its substantial impact on patients' quality of life.

Participants will be recruited either through their neurologist during routine follow-up visits at the Neurology Department of Clermont-Ferrand University Hospital or through the France Ekbom Association. Individuals interested in participating will be provided with access to the online questionnaire via a QR code or a dedicated web link. One thousand patients will be include in this study (RIPH type 3). The online questionnaire is expected to take approximately 30 minutes to complete. It includes the collection of demographic data (age, sex, lifestyle factors, weight, height, employment status, comorbidities, and dietary habits), as well as questions regarding the patient's medical history and sleep habits.

The questionnaire also includes validated instruments assessing sleep, pain, RLS severity, anxiety and depression, and quality of life.

At the end of the questionnaire, participants will be invited to take part in an optional ancillary study aimed at validating the French translation of the Restless Legs Syndrome Quality of Life questionnaire (RLS-QOL). Participants who agree to participate will complete the questionnaire once at baseline and will subsequently receive an email reminder to complete it a second time two weeks later. This test-retest procedure will be used to assess the reproducibility of the French-adapted version of the questionnaire.

Study Overview

• Status: Not yet recruiting
• Conditions: RLS
• Intervention / Treatment: Other: Patients with RLS

• Study Type: Observational
• Enrollment (Estimated): 1000

Contacts and Locations

• Study Contact: Name: Lise Laclautre; Phone Number: +33473754963; Email: promo_interne_drci@chu-clermontferrand.fr

Study Locations

• France
  • Clermont-Ferrand, France
    • CHU de Clermont-Ferrand
    • Principal Investigator: Livia FANTINI
    • Contact: Lise Laclautre; Phone Number: 33473754963; Email: promo_interne_drci@chu-clermontferrand.fr

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Patients will be contacted through the France Ekbom Association or identified during routine consultations. Those who are interested in participating in the study will be able to access the online questionnaire via a QR code or a web link.

Description

Inclusion Criteria:

• Male or female participants aged 18 years or older.
• Diagnosis of Restless Legs Syndrome (RLS) according to the criteria of the International Classification of Sleep Disorders, Third Edition (ICSD-3).
• French-speaking.

Exclusion Criteria:

• Patient under guardianship, curatorship, or legal protection measures.
• Patient who has never had an appointment with a neurologist as part of their SJSR care pathway.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

RLS patient; Patients with a diagnosis of Restless Legs Syndrome (RLS) confirmed by a sleep specialist

Other: Patients with RLS; The online questionnaire is expected to take approximately 30 minutes to complete. It includes the collection of demographic data (age, sex, lifestyle factors, weight, height, employment status, comorbidities, and dietary habits), as well as questions regarding the patient's medical history and sleep habits. The questionnaire also includes validated instruments assessing sleep, pain, RLS severity, anxiety and depression, and quality of life. At the end of the questionnaire, participants will be invited to take part in an optional ancillary study aimed at validating the French translation of the Restless Legs Syndrome Quality of Life questionnaire (RLS-QOL). Participants who agree to participate will complete the questionnaire once at baseline and will subsequently receive an email reminder to complete it a second time two weeks later.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Pain evaluation according to the Brief Pain Inventory (PBI)	at day 0

Secondary Outcome Measures

Outcome Measure	Time Frame
Pain characteristics using the DN4 questionnaire	at day 0
RLS severity using the International Restless Legs Syndrome Rating Scale (IRLS)	at day 0
Fibromyalgia using the FIRST (Fibromyalgia Rapid Screening Tool)	at day 0
Biopsychosocial dimensions of pain according to the Pain Catastrophizing Scale (PCS).	at day 0
Anxiety and depression using the Hospital Anxiety and Depression Scale (HADS)	at day 0
Quality of life using the EQ-5D-5L	at day 0
Daytime sleepiness using Epworth Sleepiness Scale (ESS).	at day 0
RLS-specific quality of life using the Restless Legs Syndrome Quality of Life questionnaire (RLS-QOL).	at day 0

Collaborators and Investigators

• Sponsor: University Hospital, Clermont-Ferrand
• Investigators: Principal Investigator: Livia FANTINI, University Hospital, Clermont-Ferrand

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 1, 2027

Study Registration Dates

• First Submitted: June 25, 2026
• First Submitted That Met QC Criteria: June 25, 2026
• First Posted (Actual): July 1, 2026

Study Record Updates

• Last Update Posted (Actual): July 1, 2026
• Last Update Submitted That Met QC Criteria: June 25, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Pain; Sleep; RLS
• Additional Relevant MeSH Terms: Neurologic Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain
• Other Study ID Numbers: RNI 2026 FANTINI (PAIN-RLS); 2026-A00401-50 (Other Identifier: IDRCB)

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