IASP DIAGNOSTIC-CRITERIA FOR COMPLEX REGIONAL PAIN SYNDROME - A PRELIMINARY EMPIRICAL VALIDATION-STUDY

Objective: To assess the ability of the international Association for the Study of Pain Complex Regional Pain Syndrome (CRPS) diagnostic cri teria and associated features to discriminate between CRPS patients an d patients with painful diabetic neuropathy. Design: Prospective asses sment of signs and symptoms in a series of CRPS and diabetic neuropath y patients. Setting: University of Washington Multidisciplinary Pain C enter. Patients: A consecutive series of 18 CRPS patients and 30 diabe tic neuropathy patients. Interventions: Patients completed a 10-item p atient history questionnaire assessing symptoms of CRPS prior to medic al evaluation. The evaluating physician completed a 10-item patient ex amination questionnaire assessing objective signs of CRPS. Outcome Mea sures: The analyses conducted were designed to test the ability of CRP S signs and symptoms and associated features to discriminate between C RPS patients and diabetic neuropathy patients. Results: Data analysis suggested that CRPS decision rules may lead to overdiagnosis of the di sorder. Diagnosis based on self-reported symptoms can be diagnosticall y useful in some circumstances, The addition of trophic tissue changes , range of motion changes, and ''burning'' quality of pain did not imp rove diagnostic accuracy, but the addition of motor neglect signs did. Test of a CRPS scoring system resulted in improved accuracy relative to current criteria and decision rules. Conclusions: Poorly understood disorders lacking prototypical signs/symptoms and diagnostic laborato ry testing must rely on the development of reliable diagnostic guideli nes. The results of this study should assist in the further refinement of the CRPS diagnostic criteria.