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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.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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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

Other trials in Canada

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 groups in NCT05473338
Study groupRoleWhat 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
HealthyHealthy 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.

  1. 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

  2. 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)
  1. 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

  2. Brief Pain Inventory (BPI) score

    A 12-item questionnaire evaluating function level and disability among pain patients

    Measured: 1 day

  3. 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

  4. 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.

  1. First posted25 Jul 2022
  2. Study start14 Apr 2022
  3. Primary completion14 Oct 2022
  4. Study completion5 Sep 2023

Resources

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)
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 29545626
  • Birklein 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 25471395
  • Harden 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 17610454
  • Minerbi 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

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.

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