Objective. To evaluate the efficacy of intravenous immune globulin (IVIG) in t Methods. An open, unblinded study of 3 patients with active disease and/or disease refractory to treatment with diazepam and/or corticosteroids, Results. All 3 bedridden patients improved substantially shortly after infusion with IVIG and regained function. Conclusion. IVIG may be useful for the treatment of SMS.