Ultrasound treatment of reflex sympathetic dystrophy

Three cases of lower extremity reflex sympathetic dystrophy (RSD) responded dramatically to a daily low dose ultrasound (0.5 watts/cm2 X 5 minutes) therapy to the tarsal tunnel and plantar nerve distribution, and the use of a shoe insert. Two of the three cases had been refractory to more standard therapy for RSD, including pharmacologic agents. All three patients preferred a conservative approach to surgical sympathectomy. No complications were observed, and all three cases are now symptom free. Daily ultrasound treatments are time-consuming and costly but are safe and may be useful for patients who refuse surgical sympathectomy. We hypothesize that ultrasound may have affected peripheral sympathetic nerve fibers. However, more indirect effects of ultrasound, such as increased blood flow to the limb, may be part of the action mechanism as well.