Effect of Corticosteroids on Inflammation at the Edge of Acute Multiple Sclerosis Plaques

Background: Multiple sclerosis (MS) affects the brain, spinal cord, and optic nerves. MS lesions can appear on the MRI (magnetic resonance imaging) scans in many ways. Sometimes they light up from the outer edge and fill inward. This is called ring enhancement. Researchers think this type of lesion may not heal as well as others. Corticosteroids are the standard treatment to reduce symptoms of MS relapse. But there is no standard treatment for people with enhancing MS lesions without signs of MS relapse. Researchers want to see if a short-term high-dose course of corticosteroids helps heal those lesions. Objective: To study the effects of short-term high-dose corticosteroids on ring-enhancing MS. Eligibility: Adults ages 18 and older who: * Have MS and a rim-enhancing lesion on a prior brain MRI * Are enrolled in another NINDS protocol Design: Participants will be screened under another protocol Participants will be randomly assigned to get either no treatment or 3 days of treatment with a corticosteroid. Participants will have: * 1 baseline visit * 3 days of high-dose steroids, intravenous or oral. If IV, participants will receive methylprednisolone by IV each day. Participants will also be prescribed medicine to protect their stomach. * Follow-up visits will be at week 13 and week 25 after randomization to treatment or no treatment. Visits include medical history and physical exam. Participants will have blood and urine tests. Participants will also have neurological exams and MRIs. Participants lie on a table that slides into a cylinder. They are in the scanner 1.5-2 hours. They get a dye through a catheter: A needle guides a thin plastic tube into an arm vein.