Reflex sympathetic dystrophy: diagnostic controversies.

Reflex sympathetic dystrophy, (RSD) is a complex physiologic response of the body to an external stimulus resulting in sympathetically mediated, usually nonanatomic pain, which is out of proportion to the inciting event or expected healing response. This complex entity has been the focus of much investigation, leading however to somewhat confusing and conflicting results and theories about the etiology and pathophysiology. There is even significant conflict about what characteristics define the clinical entity called RSD, and if these characteristics vary with the specific site of involvement. We have examined the current literature regarding these fundamental conflicts, and in addition we have evaluated the current controversies surrounding the role of Three Phase Radionuclide Bone Imaging (TPBI) for diagnosis, prognosis, and patient management. These controversies include the role of scintigraphy, the various criteria for scintigraphic diagnosis, and the reported variations in sensitivity and specificity of TPBI in RSD. We have examined several factors that may have affected these results, and potentially underestimated the value of scintigraphy in the diagnosis of RSD. In addition to the heterogeneous patient populations used to establish the diagnosis by different subspecialty physicians, these factors include duration of patient's symptoms, age of the patient population evaluated, location of the disease, and the varying scintigraphic scan interpretation criteria used.