Quantitative evaluation of sympathetic nervous system dysfunction in patients with reflex sympathetic dystrophy

The sympathetic nervous system function in 20 patients with reflex sympathetic dystrophy (RSD) of one upper extremity was examined by a non-invasive laser Doppler method to assess fingertip blood flow and vasoconstrictor response to deep inspiration. We observed an increased blood flow but an unchanged vasoconstrictor response in the affected hand in stage 1 of the disorder, but in stage 2 there was a decreased blood flow and a stronger vasoconstriction following an inspiratory gasp. Skin blood flow and vasoconstrictor response returned to normal following successful treatment of the condition. These results suggest that in RSD patients the sympathetic nervous system function is altered and is different in the various stages. The objective method used in our study may be of value in the diagnosis and management of RSD.