Management of patients with complex regional pain syndrome type I.

Complex regional pain syndrome type I (CRPS-I) includes different conditions characterized by regional pain and sensory, motor, sudomotor, vasomotor, and/or trophic findings, affecting a peripheral limb usually after a noxious event, such as a trauma or surgery. The pathophysiology is still poorly understood. Limited data are available on the incidence of CRPS-I, and the disease is underestimated and under-diagnosed. The disease shows a female preponderance approximately 3:1 with a peak age of incidence around the 5th and 6th decade. The available diagnostic criteria for CRPS-I rely on clinical criteria that are unfortunately focused on the signs and symptoms of the chronic and late disease, while little emphasis is given to the typical imaging (X-rays, bone scintigraphy, MRI) findings of the early phase. Over the last decades, several therapies have been proposed but the few studies available are often too small to be conclusive and rarely evolved to randomized controlled trials (RCTs). On the basis of the results of a few RCTs, only short courses of high bisphosphonate doses appear to provide substantial benefits. The best results are seen in patients in the early phase of the disease, often with the persistent remission or complete healing of the conditions. Since the only accredited mechanism of action of bisphosphonates is the suppression of osteoclastic bone resorption, it is likely the initial dramatic bone loss plays a role in the maintenance and evolution of CRPS-I. Short courses of high doses of bisphosphonates should be considered the treatment of choice for patients with CRPS-I.