Multiple sclerosis (MS) is a chronic, disabling disease of the central nervous system. The disease causes inflammation, destruction, and scarring of the nerve sheath (called myelin) that covers nerve fibers in the brain and spinal cord. There can also be damage to the underlying nerve itself (called the axon). As a result, electrical signals are slowed or blocked.
There are several types of MS:
A malfunction of the body's immune system seems to be the cause of MS, but exactly why that occurs is not known. Researchers are still working to understand autoimmune diseases, in which the immune system, which normally protects the body from infection and other disease, starts attacking the body. The following conditions may contribute to MS:
According to the National Multiple Sclerosis Society, about 400,000 people in the US have multiple sclerosis.
FAQs about MS. National Multiple Sclerosis Society website. Available at: http://nationalmssociety.org/ . Accessed August 2, 2010.
Multiple sclerosis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Updated July 13, 2011. Accessed August 8, 2011.
National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/ .
Last reviewed September 2012 by Rimas Lukas, MD
Last Updated: 09/12/2012