Multiple sclerosis is a baffling and unpredictable disease of the central nervous system. It is a chronic, progressive and demyelinating disease. It destroys the covering or insulating material around the nervous fibres, known as myeline. The central nervous system is the nerve center of the body. It is usually defined as the brain and spinal cord. It is linked with most nerve systems in the body, and some nerve from it continue on into parts of the body outside the brain and spinal cord.
It is a wonderfully efficient system as with the help of other nerve systems, it is constantly at work transmitting message into and out of the brain and spinal cord to and from all parts of the body 24 hours a day, even during sleep. Even the simplest action may involve scores of messages to different muscle fibres. In multiple sclerosis, these messages do not travel through the central nervous system properly and are slowed, distorted or, in some cases, blocked completely due to damage to the nerve tissue.
The disease is called multiple because many parts of the brain and spinal cord are affected. It is called sclerosis because the disease involves ‘sclerosed’ or hardened tissue in damaged areas of the brain and spinal cord. The disease usually affects people between the ages of 20 and 50 years, but can also occur before 20 or after 50 years. It is, however, not found for the first time in people over 55 years, or before adolescence. Women are slightly more affected by this disease than men.