Central sensitization in CRPS patients with widespread pain: a cross-sectional study.

"Conflicts of interest: There is no conflict of interest to declare."

"Funding This work was supported by the Clinical Research Priority Program (CRPP) Pain of the University of Zurich. Conflicts of interest: There is no conflict of interest to declare."

"This study was part of a larger study including patients with CRPS, neuropathic pain after spinal cord injury, and low back pain, as well as age- and sex-matched healthy controls (HC), which were recruited between November 2019 and April 2022. The results presented in this manuscript are based on a consecutive sample of all patients with CRPS (N = 21) and 20 age-matched HC. CRPS patients were recruited at the Department of Physical Medicine and Rheumatology of the Balgrist University Hospital in Zurich, Switzerland, and diagnosed by an experienced rheumatologist (FB). All patients needed to fulfill the clinical Budapest Criteria at inclusion and had experienced pain for more than 3 months. Patients were excluded in case of neurological (eg, polyneuropathy, disk herniation), systemic (eg, autoimmune disease, diabetes) or clinically diagnosed psychiatric diseases or in case of pregnancy. HC had the same exclusion criteria with the addition of not having acute pain or a history of chronic pain (>3 months). Written informed consent was obtained from each participant and all experimental procedures were in accordance with the Declaration of Helsinki. The study was approved by the local ethics board “Kantonale Ethikkommission Zürich, KEK” (EK-04/2006, PB_2016-02051, clinicaltrial.gov number: NCT02138344)."