Antioxidant profile in patients with complex regional pain syndrome type I

Complex regional pain syndrome (CRPS) type I is one of the most important problems with regard to physical medicine and rehabilitation. CRPS may cause not only higher therapeutic costs but also greater work time loss. The mechanism and pathogenesis of CRPS still remains unknown. Some findings indicating oxidative stress have been reported. This study was carried out to determine the role of oxidative stress in patients with CRPS.

Twenty patients (13 women and seven men) with CRPS and 20 age- and sex-matched healthy controls were enrolled in this study. Complex regional pain syndrome was diagnosed according to the modified International Association for the Study of Pain (IASP) criteria. We evaluated demographic, clinical and laboratory characteristics of the patients. Antioxidant enzymatic activities consisting of serum superoxide dismutase (SOD), glutathion peroxidase (GPX) and glutathione S-transferase (GST) activities were measured using appropriate methods and compared with healthy controls.

The mean age of the patients was 39.5 years and the mean duration of symptoms was 5.5 months. Complex regional pain syndrome devoleped after a traumatic event in 90% of patients. In 10% of patients there were no traumatic events. SOD, GPX and GST levels were significantly higher in patients with CRPS than healthy controls (P = 0.012, P = 0.036 and P = 0.016, respectively).

Our findings suggest a possible role of oxidative stress in the pathogenesis of CRPS.