The study is being done to determine if venous angioplasty is an effective treatment for chronic cerebrospinal venous insufficiency (CCSVI). In this condition, areas of narrowing or blockages are present in the internal jugular or azygos veins (veins which drain blood from the central nervous system) and these blockages may be associated with symptoms classically attributed to MS. Therefore, angioplasty may help to improve the symptoms associated with CCSVI and multiple sclerosis (MS). In this study, the investigators will evaluate the effectiveness of angioplasty in the treatment of CCSVI by comparing two the outcomes of two groups of patients: one group with CCSVI diagnosed on a venogram and treated with angioplasty and one group with CCSVI diagnosed on a venogram but not treated. The patients enrolled in this study, and the neurologist evaluating patients after the procedure, will not know whether or not they were treated with angioplasty.