[Complex regional pain syndrome type I (CRPS I). Pathophysiology, diagnostics, and therapy].

Complex regional pain syndrome type I (CRPS type I)--formerly termed Sudeck's atrophy or reflex sympathetic dystrophy (RSD)--causes chronic, poorly controllable pain, autonomic, sensorimotor disorders,and serious trophic alterations in the later stages. It develops in the distal extremities mostly after minimal trauma or surgical intervention and rarely spontaneously. The severity of symptoms is disproportionate to the causative event. The latest scientific findings show that the previously called reflex sympathetic dystrophy (RSD), which was supposed to be a result of a hyperreactive autonomic nervous system,is a very complex syndrome that occurs on different integration levels of the nervous system. Sympathetically maintained pain (SMP) may be facultatively characteristic, but is not to be misunderstood as an underlying mechanism. A neurogenic inflammation reaction has recently been discussed, just as had been postulated by Paul Sudeck long before. That was the reason why the International Association for the Study of Pain (ISAP) introduced the more descriptive term "complex regional pain syndrome" (CRPS) type I in 1994. Due to the complexity of the process necessitating qualified knowledge, it is important to immediately refer patients to a specialized pain OPD or clinic. The diagnosis of CRPS type I is based upon a carefully taken case history and a clinical examination by an experienced practitioner. Imaging diagnostic tools and laboratory findings are of no or only low predicative value. The question of whether SMP exists after diagnosing CRPS type I is eminent for therapy planning. Therefore, diagnostic regional anesthetics are still important in spite of their uncertain prognostic relevance. Physical therapy, occupational therapy, medical treatment, and psychotherapy play an important role in the primary treatment of CRPS type I as noninvasive procedures. Despite heavy criticism, invasive sympathetic block, subsequent to adequate diagnostics, is an important part of the therapeutic concept. A multimodal therapeutic concept, which includes all available possibilities, is absolutely necessary to avoid grave permanent disabilities caused by insufficient or failed therapy. Nevertheless, already established as well as new treatment modalities have to be critically observed by further randomized, prospective control trials.