A second cohort of patients starting the use of approved therapy will also be examined. Patients referred to NIH prior to beginning approved therapy will be assessed with a series of three monthly MRIs to determine the level of pretreatment disease activity. After beginning approved therapy under the direction of their private physician, patients will be followed similarly to the natural history cohort. Immunological and genetic findings will be accessed before and during therapy in order to help establish the mechanisms of action of the therapies and to identify mechanisms accounting for either a response or lack of response to therapy. Part of the collected samples willl be cryopreserved to provide respository for further studies focusing on detection of biomarkers indicative of disease state, disease stage or repsonse to therapies.