Natural History of Multiple Sclerosis and Its Mimickers

Background: - Magnetic resonance imaging (MRI) has been used for decades to help diagnose and monitor neurological disorders like multiple sclerosis (MS). Researchers want to improve how MRI pictures are taken. They also want to learn more about using newer MRIs with stronger magnets to get better pictures than standard MRIs provide. Objectives: - To collect data that will help researchers better understand MS and related diseases. Eligibility: - Adults 18 and older with MS or MRI findings that appear similar to MS, or with other neurological diseases that may look or act like MS. - Healthy adult volunteers. Design: - Participants will be screened with a review of their medical records. - Participants will have a baseline visit. It will include a physical exam, medical history, and neurological exam. They may have blood tests. - The study will last indefinitely. - Participants may have MRIs. Some MRIs may include a contrast dye. For this, a needle will be used to guide a thin plastic tube into an arm vein. - Participants may have up to 2 lumbar punctures per year. Skin will be numbed and a needle inserted between back bones will remove fluid. - Participants may give saliva samples and have an eye exam. - Participants may have evoked potential tests. These measure how the nervous system responds to different types of stimulation. Participants may sit in front of a TV and watch pictures on the screen. Or they may wear earphones that make a clicking noise or static. Or they may get a small electrical shock that may tingle and cause a hand or foot twitch. - Participants may have tests of strength, spasticity, sensations, balance, and/or walking.