An Open-label Trial of Intravenous Immune Globulin (IVIG)in Treating Spinocerebellar Ataxias

Inclusion Criteria: * Outpatients with SCA types 1, 2, 3, 6, 10, or 11, diagnosed by a movement disorder specialist. * Age 18 years to 80 years. * Able to ambulate with or without assistance for 30 feet. * Women of child-bearing potential must use a reliable method of contraception and must provide a negative pregnancy test at entry into the study. * Serum creatine kinase, complete metabolic panel, complete blood count, liver function tests, renal function tests, platelets and EKG do not reveal clinically significant abnormalities (results obtained from primary care physician and dated within the past 6 months or obtained at screening visit). * Stable doses of all medications for 30 days prior to study entry and for the duration of the study. * Diagnosis of peripheral neuropathy. See exclusion criteria 3 for specific types of peripheral neuropathy to be excluded. * Throughout the study, all possible efforts will be made to maintain subject levels of activity, exercise or physical therapy. * Subject permission (informed consent). Exclusion Criteria: * Any unstable illness that in the investigator's opinion precludes participation in this study. * Use of any investigational product within the past 30 days. * Presence of diabetes (as determined by blood glucose labs within the past 6 months), nutritional deficiency causing neuropathy (vitamin B1, 3, 6, and 12 or vitamin E), injuries, autoimmune disorders (HIV, lupus, pediatric Guillain-Barre syndrome, neurosarcoidosis, monoclonal gammopathy), tumors, infections (leprosy), exposures to toxins (alcohol, arsenic, mercury), thyroid disease or hereditary causes (cerebral amyloid angiopathy) known to result in the presence of peripheral neuropathy. * Dementia or other psychiatric illness that prevents the subject from giving informed consent (MMSE less than 25). * Legal incapacity or limited legal capacity. * Presence of severe renal disease (estimated creatinine clearance \<50 mL/min) or hepatic disease (as evidenced by labs reported within the past 6 months). * Clinically significantly abnormal white blood cell count, hemoglobin or platelet count (as evidenced by labs reported within the past 6 months). * Immunoglobulin A, Vitamin B (1, 3, 6, or 12), vitamin E or folate deficiencies (evidenced by screening lab evaluations).