Diagnosis, mechanisms and treatment of complex regional pain syndrome.

PURPOSE OF REVIEW: The incidence and disease course of complex regional pain syndrome (CRPS) has been unclear until recently. This was due to inconsistent diagnostic criteria used in previous studies and a lack of large-scale prospective datasets. Multiple mechanisms of CRPS have been suggested, and recent research has begun to explain how inflammation, the immune system and the autonomic nervous system may interact with aberrant central neuroplasticity to produce the clinical picture. This review summarizes progress in these fields.

RECENT FINDINGS: National registries of patients with CRPS have provided us with an invaluable insight into the epidemiology of the disorder. We now have a better understanding of the disease course and expected outcome. Widespread sensory abnormalities, not limited to the CRPS limb, have been found suggesting that systemic changes may occur. Parietal lobe dysfunction and problems with sensory-motor integration have also been revealed. Abnormalities in the immune system in CRPS have also been demonstrated.

SUMMARY: Recent findings in diverse research fields suggest novel treatment options for CRPS: from targeting autoimmunity to correcting abnormal body image. Many of the advances in our understanding of CRPS have arisen from the development of collaborative research efforts, such as the TREND group in the Netherlands.