Role of the Gut Microbiome in Complex Regional Pain Syndrome

Study Overview
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Brief Summary
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The objective of this prospective, observational study is to determine the association between the composition of the gut microbiota and the severity and persistence of Complex Regional Pain Syndrome symptoms (Study A). The objective of Study B, a longitudinal study of microbiota biomarkers of patients with newly diagnosed CRPS is to determine if the researchers can predict which patients are more likely to recover compared to those who do not. A secondary objective of both studies is to examine cognitive flexibility in relation to outcomes (study A and B).

Official Title
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Role of the Gut Microbiome in Complex Regional Pain Syndrome

Conditions
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Complex Regional Pain Syndromes

Participation Criteria
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Eligibility Criteria
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Study A: Cross-sectional study Inclusion criteria, cases: Adults over the age of 18 Current (< 1 year duration) or former (> 1 year) diagnosis of Complex Regional Pain Syndrome by the Budapest criteria English as primary language able to consent Inclusion criteria, controls Adults over age of 18 Cohabitant of person with current or former diagnosis of CRPS Study B: Longitudinal Study Inclusion criteria, cases: Adults over the age of 18 Recent diagnosis (<6 months) of Complex Regional Pain Syndrome by the Budapest criteria English as primary language able to consent Inclusion criteria, controls Adults over age of 18 Cohabitant of person with diagnosis of CRPS Study A and B: Exclusion criteria, cases and controls: Unwilling to participate in the study Lives alone Current use of probiotics and unwilling to stop for 1 week prior to stool sample Pregnant or lactating Vegan diet

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Study A: Chronic >1 year<br> | |
| Study A: Acute <1 year<br> | |
| Study A: Household Control<br> | |
| Study B: Newly Diagnosed <6 months<br> | |
| Study B: Household Controls<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with taxonomic and metabolomic differences of the gut microbiome in relation to CRPS severity score | Study A | 1 visit - up to one month | 
| Number of participants with taxonomic and metabolomic differences of the gut microbiome in relation to recovery from CRPS | Study B | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Score results of the Stroop Color Word Test in relation to CRPS recovery | Study B | 12 months | 
| Logistic regression analysis for testing the association of CRPS severity score to weight in kilograms and height in meters aggregated to BMI (kilograms/meters squared) | Study B | 12 months | 
| Logistic regression analysis for testing the association of CRPS severity score to use of opioid analgesics | Study B | 12 months |