What is multiple sclerosis?
(MS) is a disease of the central nervous system (CNS) that can cause problems
with muscle control and strength, balance, vision, and sensation (such as
numbness or tingling in your feet or hands).
The symptoms of MS
are caused by
inflammation of the CNS and the destruction of
myelin , the coating that surrounds and protects nerve
fibers (axons). The resulting damage disrupts the normal flow of nerve impulses
through the brain, spinal cord, and nerves that control how a person moves and
In general, MS follows one of four courses, which are
- Secondary progressive.
- Primary progressive.
- Progressive relapsing.
The severity of MS differs from person to person and can
vary within one person over time. Some people have only mild problems with
vision or sensation, while others have severe problems with movement, causing
How is multiple sclerosis diagnosed?
professionals diagnose the disease when damage typical of MS has occurred to
more than one area of the brain or spinal cord at more than one point in time.
This means that you have had at least two episodes of signs and symptoms that
could be caused by MS, such as weakness or clumsiness, vision problems,
tingling or numbness, or balance problems that a neurologist can verify.
Each episode must have lasted at least 24 hours, and the episodes should
have occurred at least 1 month apart. If you have MS, a
magnetic resonance imaging (MRI) test usually shows
damage (lesions or plaques) in more than one area of the brain or spinal cord.
How effective are medications for MS?
cannot cure MS at this time. They do not stop disease activity or progression,
and they do not reverse nervous system damage that has already occurred.
However, medications may reduce relapses and delay disability in many people
with relapsing forms of MS. Studies have shown that:
- For people with relapsing-remitting MS,
interferon beta (Avonex, Rebif, or Betaseron) can
reduce the severity of relapses, and decrease their frequency by about
one-third. They may also delay disability in some people, and decrease the
occurrence of new areas of damage (lesions).2
- Glatiramer acetate (Copaxone) can make relapses less
severe. It can also decrease their frequency by about one-third, like the
interferon beta drugs. But less is known about the effect on MS lesions or on
the development of disability. Doctors often use glatiramer acetate in milder
cases of MS.2
- Mitoxantrone (Novantrone) can also slow disease progression and decrease relapse
rates in people with relapsing-remitting and secondary progressive MS, but with
a greater chance of side effects.3
- Natalizumab (Tysabri) can decrease relapse
rates in people with relapsing-remitting MS. It can also decrease the chance
that a person with MS will be permanently disabled.4, 5 Natalizumab (Tysabri) is typically
used when other medicines for MS do not work or if the side effects of another
medicine for MS are severe. This is because it may cause a serious and
life-threatening disease called PML. Natalizumab is tightly controlled because
of this possible side effect.
- Early treatment, beginning as soon as relapsing MS is
diagnosed, seems to be most effective and is recommended by the National
Multiple Sclerosis Society. The National MS Society also says that treatment
with medicine may be considered after the first attack in some people who are
at a high risk for MS (before MS is definitely diagnosed).1
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