Abstract
Reflex sympathetic dystrophy (RSD) refers to subjective complaints of pain associated with soft-tissue changes that may not be caused by sympathetic nervous system dysfunction and for which no reflex has been demonstrated. One definition indicates that RSD, like causalgia, is manifested by pain, allodynia, hyperalgesia, and hyperesthesia and, frequently, by vasomotor and sudomotor disturbances and skeletal muscle hypotonia. The diagnosis of RSD depends on the patient's response to regional sympathetic blockade but does not take into account the questionable validity of the sympathetic mediation hypothesis, the placebo effect, or inadequately performed regional sympathetic blockade. These confounders have contributed to the misdiagnosis and overdiagnosis of RSD and causalgia. Since the publication of the AMA Guides to the Evaluation of Permanent Impairment, Fourth Edition, the International Association for the Study of Pain has proposed a new term, complex regional pain syndrome (CRPS) that replaces RDS and causalgia. Dissenting views suggest that the criteria for RDS are vague or that patients with RSD are not a homogeneous population. Evaluators should eliminate alternative diagnoses and then base a finding of RSD, causalgia, or CRPS on a preponderance of clinical evidence. [Part 2 of this article in the next issue of The Guides Newsletter will address impairment due to RSD/causalgia/CRPS.]
