title: The treatment of complex regional pain syndrome type I with free radical scavengers: a randomized controlled study.
abstract: To compare the effects of two free radical scavengers, dimethylsulfoxide 50% (DMSO) and N-acetylcysteine (NAC), for treatment of complex regional pain syndrome I (CRPS I), a randomized, double-dummy controlled, double-blind trial was conducted. Two outpatient clinics of two university hospitals in The Netherlands participated in the study and 146 patients, were included over a period of 24 months. Patients were randomized into two treatment groups, one was instructed to apply DMSO 50% five times daily to the affected extremity, the second was treated with NAC 600mg effervescent tablets three times daily, both combined with placebo. Interventions were accompanied by pain medication, occupational therapy for upper extremity CRPS I and physical therapy for lower extremity CRPS I in specific circumstances. Treatment was given for 17 weeks, with a possibility to continue or switch medication after this period, up to 1 year following the onset of treatment. An impairment level sum score was the primary outcome measure. Upper and lower extremity skills and functions, and general health status were also evaluated. Overall, no significant differences were found between NAC and DMSO after 17 and 52 weeks on impairment level and general health status. Significant differences were found for subscores of lower extremity function, in favor of DMSO-treatment. Subgroup analysis showed more favorable results for DMSO for warm CRPS I and significantly better performance of NAC for patients with a cold CRPS I. Results tended to be negatively influenced if the duration of the complaint was longer. Treatment with DMSO and NAC are generally equally effective in treatment of CRPS I. Strong indications exist for differences in effects for subgroups of patients with warm or cold CRPS I: for warm CRPS I, DMSO-treatment appears more favorable, while for cold CRPS I, NAC-treatment appears to be more effective.
authors.affiliation: Department of Anesthesiology, Vrije Universiteit Medical Center, P.O. Box 7057, 1007 MB, Amsterdam, The Netherlands Department of Clinical Epidemiology and Biostatistics, Vrije Universiteit Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands Department of Pharmacy, Vrije Universiteit Medical Center, P.O. Box 7057,1007 MB Amsterdam, The Netherlands Department of NDDO Oncology, Vrije Universiteit Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands.
authors.forename: M R S G
authors.initials: MRSG
authors.lastname: Perez
authors.forename: A W W
authors.initials: AWW
authors.lastname: Zuurmond
authors.forename: D P
authors.initials: DP
authors.lastname: Bezemer
authors.forename: J D
authors.initials: JD
authors.lastname: Kuik
authors.forename: C A
authors.initials: CA
authors.lastname: van Loenen
authors.forename: J J
authors.initials: JJ
authors.lastname: de Lange
authors.forename: J A
authors.initials: JA
authors.lastname: Zuidhof
mesh_terms: D000111:Acetylcysteine / Q000627:therapeutic use*; D000328:Adult; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D004121:Dimethyl Sulfoxide / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D016166:Free Radical Scavengers / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012019:Reflex Sympathetic Dystrophy / Q000188:drug therapy* / Q000503:physiopathology; D012044:Regression Analysis; D018709:Statistics, Nonparametric
chemical_list: D016166:Free Radical Scavengers; D000111:Acetylcysteine; D004121:Dimethyl Sulfoxide