What is Multiple Sclerosis? |
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Multiple sclerosis
(MS) is a life-long chronic disease diagnosed primarily in young adults.
During an MS attack, inflammation occurs in areas of the white matter
of the central nervous system (nerve fibers that are the site of MS
lesions) in random patches called plaques. This process is followed
by destruction of myelin, which insulates nerve cell fibers in the brain
and spinal cord. Myelin facilitates the smooth, high-speed transmission
of electrochemical messages between the brain, the spinal cord, and
the rest of the body. Symptoms of MS may be mild or severe and of long
duration or short and appear in various combinations.
The initial symptom
of MS is often blurred or double vision, red-green color distortion,
or even blindness in one eye. Most MS patients experience muscle weakness
in their extremities and difficulty with coordination and balance. Most
people with MS also exhibit paresthesias, transitory abnormal sensory
feeling such as numbness or "pins and needles." Some may experience
pain or loss of feeling. About half of people with MS experience cognitive
impairments such as difficulties with concentration, attention, memory,
and judgment. Such impairments are usually mild, rarely disabling, and
intellectual and language abilities are generally spared. Heat may cause
temporary worsening of many MS symptoms.
Physicians use a
neurological examination and take a medical history when they suspect
MS. Imaging technologies such as MRI, which provides an anatomical picture
of lesions, and MRS (magnetic resonance spectroscopy), which yields
information about the biochemistry of the brain. Physicians also may
study patients' cerebrospinal fluid and an antibody called immunoglobulin
G. No single test unequivocally detects MS. A number of other diseases
produce symptoms similar to those seen in MS.