Overview

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).

Eligibility

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