What is Multiple Sclerosis (MS)?
Multiple sclerosis (MS) involves an immune-mediated process in which an abnormal response of the body’s immune system is directed against the central nervous system (CNS), which is made up of the brain, spinal cord and optic nerves. The exact antigen — or target that the immune cells are sensitized to attack — remains unknown, which is why MS is considered by many experts to be "immune-mediated" rather than "autoimmune."
Within the CNS, the immune system attacks myelin--the fatty substance that surrounds and insulates the nerve fibers — as well as the nerve fibers themselves. The damaged myelin forms scar tissue (sclerosis), which gives the disease its name. When any part of the myelin sheath or nerve fiber is damaged or destroyed, nerve impulses traveling to and from the brain and spinal cord are distorted or interrupted, producing a wide variety of symptoms.
What causes MS?
While the cause (etiology) of MS is still not known, scientists believe that the interaction of several different factors may be involved. To answer this important question, studies are ongoing in the areas of immunology (the science of the body’s immune system), epidemiology (the study of patterns of disease in the population) and genetics. Scientists are also studying infectious agents that may play a role. Understanding what causes MS will speed the process of finding more effective ways to treat it and — ultimately — cure it, or even prevent it from occurring in the first place.