Causes of Multiple Sclerosis
Most scientists believe that multiple sclerosis is an autoimmune disorder, meaning that the body mistakenly attacks part of itself -- in this case, the fatty sheath protecting nerves. Genetic and environmental factors may contribute to multiple sclerosis, but more research is needed in these areas before we will know the exact cause or causes of the disease.
The causes of multiple sclerosis are still unknown. For reasons not yet understood, the fatty substance called myelin (which covers nerve fibers) is damaged in random areas. The areas of damage are known as plaques. Myelin normally insulates entire nerve fibers. It helps nerve messages to be quickly and properly conducted to and from the brain. The symptoms of multiple sclerosis depend on where these plaques occur in the central nervous system.
Many investigators believe multiple sclerosis is an autoimmune disease. An autoimmune disease is a condition in which the body, through its immune system, mistakenly launches a defensive attack against its own tissues. In the case of multiple sclerosis, the nerve-insulating myelin comes under assault. Such assaults may be linked to an unknown environmental trigger, perhaps a virus.
Scientists have studied a number of infectious agents (such as viruses) that have been suspected as potential causes of multiple sclerosis, but have been unable to implicate any one particular agent as the sole cause of the disease.
It is possible that the immune system's response to viral infections may itself precipitate a multiple sclerosis attack. There seems to be little doubt that something in the environment is involved in triggering multiple sclerosis.