Complex regional pain syndrome underdiagnosed
CRPS type 1 is an under-recognized problem in limbs recovering from fracture or immobilized post-stroke.
Using the diagnostic criteria. Once other disorders have been ruled out, evidence does support the diagnosis of CRPS type 1 based on history and physical exam without further testing (SOR: B). In the absence of clear evidence supporting 1 set of criteria over the others, clinicians may use IASP, Bruehl’s, or Veldman’s clinical criteria for diagnosis (SOR: C). While the IASP criteria are nonspecific and possibly not as reproducible as Bruehl’s or Veldman’s criteria, they are cited more widely the literature including treatment trials. The criteria (FIGURE) can also be combined to encompass their complementary aspects (SOR: C, this author’s opinion).
CRPS has historically been described as comprising 2 distinct subtypes: type 1, also known as reflex sympathetic dystrophy, in which nerve damage is not detectable, and type 2, also known as causalgia, in which nerve damage can be detected by electromyograph (EMG) but pain is not confined to the distribution of that nerve.4 However, the clinical relevance of distinguishing the 2 types of CRPS has not been proven. Although the mechanism of pain is hypothesized to be different, thus far the 2 syndromes appear to be clinically similar (LOE: 2, case-control study).11 Many, but not all, recent articles on treatment of CRPS combine types 1 and 2 in their subject populations. Yet, because CRPS types 1 and 2 have not yet been officially merged and because some researchers continue to make the distinction in studies, this paper will focus on CRPS type 1.
The nature of, diagnostic criteria for, and even the naming of CRPS have been controversial. In 1995 the International Association for the Study of Pain (IASP) recommended abandoning the commonly used term reflex sympathetic dystrophy because: 1) the existence of a “reflex” is questionable, 2) “sympathetic” or autonomic changes may not be causative, and 3) “dystrophy” is rare.4 Despite this recommendation, a review of the literature 5 years later revealed that the terms reflex sympathetic dystrophy and causalgia are still commonly used, along with algodystrophy, shoulder-hand syndrome, Sudeck’s atrophy, and transient osteoporosis.42
ACKNOWLEDGMENTS
The authors would like to express their appreciation to Cheryl Mongillo, Peggy Lardear, and Brian Pellini for their assistance in preparing the manuscript, Dolores Moran and Diane Wolfe for their assistance in finding articles, and to Roger Rodrigue, MD for reviewing the manuscript. Funding for this project was provided by a grant from the Delaware Department of Health and Social Services, Division of Public Health.
CORRESPONDING AUTHOR
Anna Quisel, MD, Anna Quisel, MD, c/o Cheryl Mongillo, Family Medicine Center, 1401 Foulk Road, Wilmington, DE 19803. E-mail: bretandanna@comcast.net.
