This evaluation will be a one-year feasibility study to characterize the neuroprotective benefits of Gilenya and its effects on cognition and grey matter volumes. The study will enroll 15 patients with relapsing-remitting multiple sclerosis being treated with Gilenya and 5 healthy controls. Each participant will undergo a battery of neurometric testing at baseline, six months, and one year. In addition, patients will undergo high-field 7T MRI at the same time points.