CRPSNCT05473338
Complex Regional Pain Syndrome (CRPS) and the Gut-bacteria
An observational study of CRPS, run by McGill University Health Centre/Research Institute of the McGill University Health Centre at 1 site in Canada.
Trial summary
The purpose of this study is to investigate, for the first time, whether gut bacteria composition and function of patients with CRPS differ from those of healthy adults. Samples of stool, urine and blood will be collected from patients with CRPS and from healthy adults. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- CRPS
- What is being tested?
- Stool and blood samples, Physical examination and Questionnaires
- How many people
- 105 participants
- Where
- 1 siteCanada
- Study dates
- 14 Apr 2022to 5 Sep 2023
- Phase
- Observational
- Are there results?
- None posted in the registry
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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Adult women and men with CRPS and healthy volunteers.
Who may be able to join
- Women and men over the age of 18, diagnosed with CRPS of the upper or lower limb according to the Clinical Budapest Criteria, with a duration of 6 months and over (for the 1st study group).
- Healthy women and men over the age of 18, who share a household with a CRPS patients participating in the study (for the 1st control group).
- Healthy women and men over the age of 18 (for the 2nd control group).
- Be able to read and write in either French, English or Hebrew.
Who cannot join
- Any major illness (eg. malignancy, active inflammatory disease, metabolic disease, etc.)
- Pregnancy
- Chronic pain conditions (other than CRPS in the patients group)
- Acute illness of any type in the preceding 1 month
- Use of systemic antibiotics in the preceding 1 month
- Change in any other regularly taken medications in the past 1 month
- Substantial dietary / gastrointestinal alterations in the past 1 month.
- The inclusion/exclusion criteria were set to reduce the risk of confounding factors that could affect gut microbiota composition.
Trial locations and contacts
1 site in 1 country.
Canada1 site
Alan Edwards Pain Management Unit - Montreal General Hospital
Montreal, Quebec, H3G 1A4
About this study
Official title: Comparison of Gut Microbial Composition and Function in CRPS Patients vs. Healthy Individuals
The purpose of this study is to investigate, for the first time, whether gut bacteria composition and function of patients with CRPS differ from those of healthy adults. Samples of stool, urine and blood will be collected from patients with CRPS and from healthy adults. The type and function of bacteria of CRPS patients will be analyzed and compared to those of healthy adults to test if potential differences could explain the mechanism/s involved with the development of CRPS.
- Conditions
- CRPS
- Being tested
- Stool and blood samples, Physical examination, Questionnaires
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Stool and blood samplesDiagnostic test
fecal microbiome and metabolomics, as well as metabolites in plasma
Physical examinationOther
physical examination performed by a physician to confirm CRPS diagnosis and assess patient's eligibility to participate in the study. The exam will include skin temperature measured using a laser/infrared skin thermometry.
QuestionnairesOther
Questionnaires measuring pain level, sleep, mood and diet parameters.
| Study group | Role | What they receive |
|---|---|---|
| CRPS (Complex Regional Pain Syndrome) | Participants with CRPS (Complex Regional Pain Syndrome)) Receives: Diagnostic Test: Stool and blood samples; Other: Physical examination; Other: Questionnaires | |
| Healthy | Healthy individuals Receives: Diagnostic Test: Stool and blood samples; Other: Questionnaires |
What is being measured
The primary outcome is the main question the study is designed to answer.
Gut microbiome composition
Assessment of genomic composition of the gut bacteria by differential abundance analysis will be performed using 16S rRNA (Genome-Quebec)
Measured: 1 day
Presence of stool microbiota-related metabolites affecting host physiology
Concentration of bile acids and short-chain-fatty-acids through Metabolomics analysis (Metabolon, USA).
Measured: 1 day
Secondary outcomes (4)
Short-form health-questionnaire (SF12) score
A 12-item measure of health-related quality of life, validated in a variety of population groups
Measured: 1 day
Brief Pain Inventory (BPI) score
A 12-item questionnaire evaluating function level and disability among pain patients
Measured: 1 day
Patient Health Questionnaire (PHQ-9) score
A 9 item inventory rated on a 4 point Likert-type scale used for screening for depression and anxiety
Measured: 1 day
Pittsburg Sleep Quality Index (PSQI) scores
A standardized self-administered questionnaire for the assessment of subjective sleep quality
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jul 2022
- Study start14 Apr 2022
- Primary completion14 Oct 2022
- Study completion5 Sep 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for CRPSStudies of the same condition, open and under way.
- More trials run by McGill University Health Centre/Research Institute of the McGill University Health CentreThe 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
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 105 participants (actual)
Sponsor and investigators
- Lead sponsor
- McGill University Health Centre/Research Institute of the McGill University Health Centre
- Sponsor type
- University, hospital or other
- Collaborators
- Louise and Alan Edwards Foundation, Rambam Health Care Campus
- Responsible party
- Principal investigator, Dr. Yoram Shir, McGill University Health Centre/Research Institute of the McGill University Health Centre
- Investigators
- Yoram Shir, MD, Principal investigator, McGill University Health Centre/Research Institute of the McGill University Health Centre
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05473338
- Sponsor's protocol ID
- CRPS-MB 2021-6735
- Status last verified
- Oct 2026
- First submitted
- 12 Apr 2022
- Last updated
- 23 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Birklein F, Ajit SK, Goebel A, Perez RSGM, Sommer C. Complex regional pain syndrome - phenotypic characteristics and potential biomarkers. Nat Rev Neurol. 2018 May;14(5):272-284. doi: 10.1038/nrneurol.2018.20. Epub 2018 Mar 16.
PubMed 29545626Birklein F, O'Neill D, Schlereth T. Complex regional pain syndrome: An optimistic perspective. Neurology. 2015 Jan 6;84(1):89-96. doi: 10.1212/WNL.0000000000001095. Epub 2014 Dec 3.
PubMed 25471395Harden RN, Bruehl S, Stanton-Hicks M, Wilson PR. Proposed new diagnostic criteria for complex regional pain syndrome. Pain Med. 2007 May-Jun;8(4):326-31. doi: 10.1111/j.1526-4637.2006.00169.x.
PubMed 17610454Minerbi A, Gonzalez E, Brereton NJB, Anjarkouchian A, Dewar K, Fitzcharles MA, Chevalier S, Shir Y. Altered microbiome composition in individuals with fibromyalgia. Pain. 2019 Nov;160(11):2589-2602. doi: 10.1097/j.pain.0000000000001640.
PubMed 31219947
Study at a glance
From the registry record, last updated by the sponsor on 23 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Gut Microbial Composition and Function in CRPS Patients vs. Healthy Individuals
- ClinicalTrials.gov ID
- NCT05473338
- Acronym / sponsor ID
- CRPS-MB 2021-6735
- Conditions
- CRPS
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 105 participants (actual)
- Lead sponsor
- McGill University Health Centre/Research Institute of the McGill University Health CentreUniversity, hospital or other
- Collaborators
- Louise and Alan Edwards Foundation, Rambam Health Care Campus
- Study start
- 14 Apr 2022 (actual)
- Primary completion
- 14 Oct 2022 (actual)
- Study completion
- 5 Sep 2023 (actual)
- First posted
- 25 Jul 2022 (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.
The purpose of this study is to investigate, for the first time, whether gut bacteria composition and function of patients with CRPS differ from those of healthy adults. Samples of stool, urine and blood will be collected from patients with CRPS and from healthy adults. The type and function of bacteria of CRPS patients will be analyzed and compared to those of healthy adults to test if potential differences could explain the mechanism/s involved with the development of CRPS.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CRPS (Complex Regional Pain Syndrome) | – | Diagnostic Test: Stool and blood samples, Other: Physical examination, Other: QuestionnairesParticipants with CRPS (Complex Regional Pain Syndrome)) |
| Healthy | – | Diagnostic Test: Stool and blood samples, Other: QuestionnairesHealthy individuals |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Adult women and men with CRPS and healthy volunteers.
Key inclusion criteria (4 listed)
- Women and men over the age of 18, diagnosed with CRPS of the upper or lower limb according to the Clinical Budapest Criteria, with a duration of 6 months and over (for the 1st study group).
- Healthy women and men over the age of 18, who share a household with a CRPS patients participating in the study (for the 1st control group).
- Healthy women and men over the age of 18 (for the 2nd control group).
- Be able to read and write in either French, English or Hebrew.
Key exclusion criteria (8 listed)
- Any major illness (eg. malignancy, active inflammatory disease, metabolic disease, etc.)
- Pregnancy
- Chronic pain conditions (other than CRPS in the patients group)
- Acute illness of any type in the preceding 1 month
- Use of systemic antibiotics in the preceding 1 month
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 |
|---|---|---|
| Stool and blood samplesfecal microbiome and metabolomics, as well as metabolites in plasma | Diagnostic test | CRPS (Complex Regional Pain Syndrome), Healthy |
| Physical examinationphysical examination performed by a physician to confirm CRPS diagnosis and assess patient's eligibility to participate in the study. The exam will include skin temperature measured using a laser/infrared skin thermometry. | Other | CRPS (Complex Regional Pain Syndrome) |
| QuestionnairesQuestionnaires measuring pain level, sleep, mood and diet parameters. | Other | CRPS (Complex Regional Pain Syndrome), Healthy |
Primary outcome
Gut microbiome composition
Time frame: 1 day
Assessment of genomic composition of the gut bacteria by differential abundance analysis will be performed using 16S rRNA (Genome-Quebec)
Presence of stool microbiota-related metabolites affecting host physiology
Time frame: 1 day
Concentration of bile acids and short-chain-fatty-acids through Metabolomics analysis (Metabolon, USA).
4 secondary outcomes
Short-form health-questionnaire (SF12) score
Time frame: 1 day
Brief Pain Inventory (BPI) score
Time frame: 1 day
Patient Health Questionnaire (PHQ-9) score
Time frame: 1 day
Pittsburg Sleep Quality Index (PSQI) scores
Time frame: 1 day
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Oct 2026.
- Background: PubMed 29545626Birklein F, Ajit SK, Goebel A, Perez RSGM, Sommer C. Complex regional pain syndrome - phenotypic characteristics and potential biomarkers. Nat Rev Neurol. 2018 May;14(5):272-284. doi: 10.1038/nrneurol.2018.20. Epub 2018 Mar 16.
- Background: PubMed 25471395Birklein F, O'Neill D, Schlereth T. Complex regional pain syndrome: An optimistic perspective. Neurology. 2015 Jan 6;84(1):89-96. doi: 10.1212/WNL.0000000000001095. Epub 2014 Dec 3.
- Background: PubMed 17610454Harden RN, Bruehl S, Stanton-Hicks M, Wilson PR. Proposed new diagnostic criteria for complex regional pain syndrome. Pain Med. 2007 May-Jun;8(4):326-31. doi: 10.1111/j.1526-4637.2006.00169.x.
- Background: PubMed 31219947Minerbi A, Gonzalez E, Brereton NJB, Anjarkouchian A, Dewar K, Fitzcharles MA, Chevalier S, Shir Y. Altered microbiome composition in individuals with fibromyalgia. Pain. 2019 Nov;160(11):2589-2602. doi: 10.1097/j.pain.0000000000001640.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Yoram Shir, MD principal investigator
McGill University Health Centre/Research Institute of the McGill University Health Centre
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of CRPS, run by McGill University Health Centre/Research Institute of the McGill University Health Centre at 1 site in Canada.
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 4 inclusion and 8 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: finished, as of the sponsor's last update on 23 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Gut microbiome composition (time frame: 1 day). The study lists 2 primary outcomes in all. 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 NCT05473338, which also lists 4 linked publications.
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 23 Oct 2026.