Laboratory findings in reflex sympathetic dystrophy: A preliminary report

Objective: The purpose of our study was to compare sudomotor and vasomotor indices in patients with clinical reflex sympathetic dystrophy. Design: Vasomotor tone was determined by measuring skin blood flow with laser Doppler flowmeters and skin temperature by infrared thermometry. Resting and evoked sweat output was measured with the quantitative sudomotor axon reflex test. Control values were determined from studies on 223 normal subjects. Setting: The setting was a tertiary/academic medical center. Patients: There were 12 patients with clinical reflex sympathetic dystrophy in an extremity. Main Outcome Measures: These were skin vasomotor tone and evoked sweat output. Results: Resting sweat output asymmetry was seen in 67% of patients, quantitative sudomotor axon reflex test asymmetry was seen in 75%, and vasomotor changes in 80%. When sudomotor and vasomotor indices were combined, abnormalities were seen in all patients. Conclusions: Laboratory quantitation of autonomic indices enhances the clinical evaluation of patients with reflex sympathetic dystrophy.