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MS is a nerve disorder caused by
destruction of the insulating layer surrounding neurons in the brain
and spinal cord. This insulation, called myelin, helps electrical
signals pass quickly and smoothly between the brain and the rest of
the body. When the myelin is destroyed, nerve messages are sent more
slowly and less efficiently. Patches of scar tissue, called plaques,
form over the affected areas, further disrupting nerve communication.
The symptoms of MS occur when the brain and spinal cord nerves no
longer communicate properly with other parts of the body. MS causes
a wide variety of symptoms and can affect vision, balance, strength,
sensation, coordination, and bodily functions.
Multiple sclerosis affects more than
a quarter of a million people in the United States. Most people have
their first symptoms between the ages of 20 and 40; symptoms rarely
begin before 15 or after 60. Women are almost twice as likely to get
MS as men, especially in their early years. People of northern
European heritage are more likely to be affected than people of
other racial backgrounds, and MS rates are higher in the United
States, Canada, and Northern Europe than in other parts of the world.
MS is very rare among Asians, North and South American Indians, and
Eskimos. |
