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What Is Multiple Sclerosis? MS is an autoimmune
disease, whereby the body's immune system, which normally
targets and destroys substances foreign to the body such as
bacteria, mistakenly attacks normal tissues. In MS, the immune
system attacks the brain and spinal cord, the two components
of the central nervous system.
The central nervous system is made up of nerves that act as
the body's messenger system. Each nerve is covered by a fatty
substance called myelin, which insulates the nerves and helps
in the transmission of nerve impulses, or messages, between
the brain and other parts of the body. These messages control
muscle movements, such as walking and talking.
MS gets its name from the buildup of scar tissue
(sclerosis) in the brain and/or spinal cord. The scar tissue
or plaques form when the protective and insulating myelin
covering the nerves is destroyed, a process called
demyelination. Without the myelin, electrical signals
transmitted throughout the brain and spinal cord are disrupted
or halted. The brain then becomes unable to send and to
receive messages. It is this breakdown of communication that
causes the symptoms of MS.
Although the nerves can regain myelin, this process is not
fast enough to outpace the deterioration that occurs in MS.
The types of symptoms, severity of symptoms, and the course of
MS vary widely, partly due to the location of the scar tissue
and the extent of demyelination.
Multiple sclerosis affects 350,000 Americans and is, with
the exception of trauma, the most frequent cause of
neurological disability beginning in early to middle
adulthood. MS is twice as common in females as in males and
its occurrence is unusual before adolescence. A person has an
increased risk of developing the disease from the teen years
to age 35 with the risk gradually declining thereafter.
What Causes MS? No one is sure what causes the
body's immune system to go awry
