Complex regional pain syndrome: what's in a name?

Abstract

Within a 2-year period in the 1940s, 2 Boston physicians published dramatically opposing views on the underlying nature of a syndrome now known as complex regional pain syndrome (CRPS). Evans suggested, in several papers in 1946-1947, that sympathetic reflexes maintain pain and dystrophy in affected limbs. Foisie, in 1947, suggested arterial vasospasms were key in the etiology of this pain syndrome. Evans' hypothesis established the nomenclature for this syndrome for 60 years, and his term, "reflex sympathetic dystrophy," guided clinical treatment and research activities over the same period. Foisie's proposed nomenclature was unrecognized, and had virtually no impact on the field. Recent evidence suggests that Evans' contribution to the field may have in fact led clinicians and researchers astray all those years. This focus article on CRPS compares recent observations with these 2 earlier theories and asks the question-what if we had adopted Foisie's nomenclature from the beginning?

Perspective: This article discusses 2 opposing historical views on the etiology of what is now known as CRPS, and how they affected nomenclature, research, and clinical therapy in subsequent decades. This focus article may help researchers and clinicians realize the importance of syndrome names, and how they may inadvertently misdirect research and treatment.

Fig. 1. Impact of Evans’ and Foisie’s papers on the field

A) Histogram of the numbers of Science Citation Index citations found for the papers of Evans^– and Foisie, respectively by decade between 1940 and 2009. B) Histogram of the numbers of Medline citations found for the terms “reflex sympathetic dystrophy” and “traumatic arterial vasospasm” by decade between 1950 and 2009.

Fig. 2. Consensus views of therapy for CRPS at the end of the 20^th century

Therapeutic algorithm (“Diagnosis CRPS Care Continuum” with emphasis on therapeutic options in response to patient’s clinical progress in the rehabilitation pathway. Based on the Interdisciplinary Clinical Pathway for CRPS prepared by an Expert Panel in Cardiff, Wales in 2001 (reprinted with permission from Stanton-Hicks et al, An updated interdisciplinary clinical pathway for CRPS: Report of an expert panel. Pain Practice, John Wiley and Sons).

Fig. 3. Very recent views on therapy for CRPS

Summary chart of the 2007 evidence-based guidelines for complex regional pain syndrome reported by the Netherlands Society of Rehabilitation Specialists and the Netherlands Society of Anesthesiologists. Reprinted with permission of the Dutch Institute for Health Care Improvement, Evidence-Based Guidelines Development programme (EBGD) of the Order of Medical Specialists.