Restless Legs SyndromeNCT06684782
Prevalence and Characteristics of Restless Leg Syndrome in Thai Patients With Parkinson's Disease
An observational study of Restless Legs Syndrome, run by Siriraj Hospital at 2 sites in Thailand.
Trial summary
Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by pathologic intraneuronal alpha-synuclein-positive Lewy bodies and neuronal cell loss. The cardinal clinical symptoms and signs of PD are bradykinesia, rigidity, tremor, postural instability, and freezing attacks. Read more about this study
- Who is it for?
- Ages 18 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Restless Legs Syndrome
- What is being tested?
- Screening for symptoms of restless leg syndrome
- How many people
- 310 participants
- Where
- 2 sitesThailand
- Study dates
- 1 Dec 2024to 30 Nov 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 18 to 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients with Parkinson's disease aged from 18 to 80 years who met the UK Parkinson's Disease Society Brain Bank Diagnostic Criteria. The patients must regularly visit the movement disorders clinic at least 2 times per year.
Who may be able to join
- Patients with Parkinson's disease aged from 18 to 80 years who met the United Kingdom Parkinson's Disease Society (UKPDS) Brain Bank Diagnostic criteria.
Who cannot join
- Patients with atypical or secondary parkinsonism.
- Patients with Mini-mental status exam (MMSE) less than 24 of 30.
- Patients with secondary causes of restless leg syndrome including end-stage renal disease, iron deficiency anemia and pregnancy.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Thailand2 sites, 2 recruiting
- Recruiting
Siriraj Hospital, Mahidol University
Bangkok, Bangkok, 10700
Jindapa Srikajon, MD., +66875932929, jindapas@hotmail.com
- Recruiting
Siriraj Hospital, Mahidol University
Bangkok, Thailand, 10310
Wattanachai Chotinaiwatttarakul, Doctor of Medicine, +6624197777, exchot@yahoo.com
About this study
Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by pathologic intraneuronal alpha-synuclein-positive Lewy bodies and neuronal cell loss. The cardinal clinical symptoms and signs of PD are bradykinesia, rigidity, tremor, postural instability, and freezing attacks. The prevalence of PD increases with age, affecting 1-2% of the population over the age of 65 years, and 3% of those over 85 years.
Restless legs syndrome (RLS) represents disturbing symptoms in lower limbs that lead to the urge to move, occurring in rest periods. Movements can partially or completely relieve these abnormal feelings. In 2014, the International RLS Study Group (IRLSSG) established five mandatory criteria for the diagnosis of RLS. Several studies supported that RLS and PD may share pathophysiological mechanisms.
Read the detailed description
In the general population, the prevalence of RLS was reported to be up to 10%. In Parkinson's disease (PD), the mean prevalence of RLS was 15.74%. Cross-sectional studies show a variable prevalence of RLS in PD patients ranging approximately from 0 to 50%. In case-control studies, the mean prevalence of RLS was higher in people with PD (12%) vs. healthy controls (5.1%). One four-year longitudinal study reported an increase in RLS prevalence from 4.6% to 16.3% along with disease progression. Interestingly, RLS was found to have various prevalence depending on geographic areas: highest in European populations (5% to 12%), intermediate in Asian countries (1% to 8%), and lowest in African countries (<1%).
In Patients with Parkinson's disease, diagnosis of RLS is challenging due to multiple confounders such as motor fluctuations, akathisia, etc. It is crucial to pick up RLS in Parkinson's disease and properly manage the symptoms. RLS not only causes impaired quality of life but also possibly leads to cardiovascular consequences. RLS was associated with statistically significantly less future cardiovascular risk in RLS patients with treatment than in those without treatment. Nevertheless, there have been no consistent studies of this association in Parkinson's disease yet.
From the literature review, very few data have been stated regarding RLS in Thai patients with Parkinson's disease. There was only one study focusing on the prevalence of RLS in Thailand, in which the prevalence of RLS in Thai Parkinson's patients was only 1.6%. According to the author, there were possible explanations for the low prevalence. Firstly, they only included participants with idiopathic RLS. Secondly, high doses of dopaminergic agents might obscure the symptoms of RLS in those patients with Parkinson's disease. Moreover, they screened patients with the Cambridge-Hopkins diagnostic questionnaire which had not been validated in Thai people yet. For all these reasons, we believe that the prevalence of RLS in Thai patients with Parkinson's disease would be different with another methodology. We also would like to know more about the characteristics of RLS in Thai Parkinson's disease patients, which might help improve RLS detection in this population.
- Conditions
- Restless Legs Syndrome
- Being tested
- Screening for symptoms of restless leg syndrome
- Keywords
- restless leg syndrome, parkinson's disease, prevalence, Thai population
- Medical subject headings
- Restless Legs Syndrome, Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Screening for symptoms of restless leg syndromeOther
The patients will be screened for restless leg syndrome by clinical questioning.
| Study group | Role | What they receive |
|---|---|---|
| Patients with parkinson's disease | Not described Receives: Other: Screening for symptoms of restless leg syndrome |
What is being measured
The primary outcome is the main question the study is designed to answer.
The prevalence of restless leg syndrome in patients with Parkinson's disease
Measured: At the time of recruitment
Secondary outcomes (1)
Clinical characteristics of Parkinson's disease patients with restless leg syndrome
Measured: At the time of recruitment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Nov 2024
- Study start1 Dec 2024
- Primary completion31 Oct 2026 (estimated)
- Study completion30 Nov 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Restless Legs SyndromeStudies of the same condition, open and under way.
- 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 310 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Siriraj Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jindapa Srikajon, Siriraj Hospital
- Investigators
- Jindapa Srikajon, Doctor of Medicine, Principal investigator, Siriraj Sleep Center, Faculty of Medicine, Siriraj Hospital, Mahidol University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06684782
- Sponsor's protocol ID
- 762/2567(IRB1)
- Status last verified
- May 2025
- First submitted
- 10 Nov 2024
- Last updated
- 15 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Srikajon J, Srivanitchapoom P, Pitakpatapee Y, Saengphatrachai W, Pisarnpong A, Pimolsri C, Wangthumrong T, Udompunturuk S, Engchuan M, Nurak P, Chotinaiwattarakul W. Underrecognized restless legs syndrome in Parkinson's disease: Diagnostic delay, association with sleep burden, and dopaminergic exposure in a Thai cohort. Sleep Med. 2026 Sep 8;148:109258. doi: 10.1016/j.sleep.2026.109258. Online ahead of print.
PubMed 42721723
Study at a glance
From the registry record, last updated by the sponsor on 15 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prevalence and Characteristics of Restless Leg Syndrome in Thai Patients With Parkinson's Disease
- ClinicalTrials.gov ID
- NCT06684782
- Acronym / sponsor ID
- 762/2567(IRB1)
- Conditions
- Restless Legs Syndrome
- Keywords
- restless leg syndrome, parkinson's disease, prevalence, Thai population
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 310 participants (estimated)
- Lead sponsor
- Siriraj HospitalUniversity, hospital or other
- Study start
- 1 Dec 2024 (actual)
- Primary completion
- 31 Oct 2026 (estimated)
- Study completion
- 30 Nov 2026 (estimated)
- First posted
- 12 Nov 2024 (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.
Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by pathologic intraneuronal alpha-synuclein-positive Lewy bodies and neuronal cell loss. The cardinal clinical symptoms and signs of PD are bradykinesia, rigidity, tremor, postural instability, and freezing attacks. The prevalence of PD increases with age, affecting 1-2% of the population over the age of 65 years, and 3% of those over 85 years.
Restless legs syndrome (RLS) represents disturbing symptoms in lower limbs that lead to the urge to move, occurring in rest periods. Movements can partially or completely relieve these abnormal feelings. In 2014, the International RLS Study Group (IRLSSG) established five mandatory criteria for the diagnosis of RLS. Several studies supported that RLS and PD may share pathophysiological mechanisms.
Detailed description
In the general population, the prevalence of RLS was reported to be up to 10%. In Parkinson's disease (PD), the mean prevalence of RLS was 15.74%. Cross-sectional studies show a variable prevalence of RLS in PD patients ranging approximately from 0 to 50%. In case-control studies, the mean prevalence of RLS was higher in people with PD (12%) vs. healthy controls (5.1%). One four-year longitudinal study reported an increase in RLS prevalence from 4.6% to 16.3% along with disease progression. Interestingly, RLS was found to have various prevalence depending on geographic areas: highest in European populations (5% to 12%), intermediate in Asian countries (1% to 8%), and lowest in African countries (<1%).
In Patients with Parkinson's disease, diagnosis of RLS is challenging due to multiple confounders such as motor fluctuations, akathisia, etc. It is crucial to pick up RLS in Parkinson's disease and properly manage the symptoms. RLS not only causes impaired quality of life but also possibly leads to cardiovascular consequences. RLS was associated with statistically significantly less future cardiovascular risk in RLS patients with treatment than in those without treatment. Nevertheless, there have been no consistent studies of this association in Parkinson's disease yet.
From the literature review, very few data have been stated regarding RLS in Thai patients with Parkinson's disease. There was only one study focusing on the prevalence of RLS in Thailand, in which the prevalence of RLS in Thai Parkinson's patients was only 1.6%. According to the author, there were possible explanations for the low prevalence. Firstly, they only included participants with idiopathic RLS. Secondly, high doses of dopaminergic agents might obscure the symptoms of RLS in those patients with Parkinson's disease. Moreover, they screened patients with the Cambridge-Hopkins diagnostic questionnaire which had not been validated in Thai people yet. For all these reasons, we believe that the prevalence of RLS in Thai patients with Parkinson's disease would be different with another methodology. We also would like to know more about the characteristics of RLS in Thai Parkinson's disease patients, which might help improve RLS detection in this population.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Patients with parkinson's disease | – | Other: Screening for symptoms of restless leg syndrome |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with Parkinson's disease aged from 18 to 80 years who met the UK Parkinson's Disease Society Brain Bank Diagnostic Criteria. The patients must regularly visit the movement disorders clinic at least 2 times per year.
Key inclusion criteria (1 listed)
- Patients with Parkinson's disease aged from 18 to 80 years who met the United Kingdom Parkinson's Disease Society (UKPDS) Brain Bank Diagnostic criteria.
Key exclusion criteria (3 listed)
- Patients with atypical or secondary parkinsonism.
- Patients with Mini-mental status exam (MMSE) less than 24 of 30.
- Patients with secondary causes of restless leg syndrome including end-stage renal disease, iron deficiency anemia and pregnancy.
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 |
|---|---|---|
| Screening for symptoms of restless leg syndromeThe patients will be screened for restless leg syndrome by clinical questioning. | Other | Patients with parkinson's disease |
Primary outcome
The prevalence of restless leg syndrome in patients with Parkinson's disease
Time frame: At the time of recruitment
1 secondary outcome
Clinical characteristics of Parkinson's disease patients with restless leg syndrome
Time frame: At the time of recruitment
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 15 May 2025.
- Derived from this study: PubMed 42721723Srikajon J, Srivanitchapoom P, Pitakpatapee Y, Saengphatrachai W, Pisarnpong A, Pimolsri C, Wangthumrong T, Udompunturuk S, Engchuan M, Nurak P, Chotinaiwattarakul W. Underrecognized restless legs syndrome in Parkinson's disease: Diagnostic delay, association with sleep burden, and dopaminergic exposure in a Thai cohort. Sleep Med. 2026 Sep 8;148:109258. doi: 10.1016/j.sleep.2026.109258. Online ahead of print.
- Individual participant dataSharing planned: Undecided
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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.
Jindapa Srikajon, Doctor of Medicine principal investigator
Siriraj Sleep Center, Faculty of Medicine, Siriraj Hospital, Mahidol University
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Restless Legs Syndrome, run by Siriraj Hospital at 2 sites in Thailand.
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 1 inclusion and 3 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 15 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Thailand. 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 Jindapa Srikajon, Doctor of Medicine (+66875932929, jindapas@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The prevalence of restless leg syndrome in patients with Parkinson's disease (time frame: At the time of recruitment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06684782, which also lists 1 linked publication.
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 15 May 2025.