.......No
matter what language it is written in, of this Earth or not, it is still
the same thing. A Dis-Ease! The following is from a pamphlet
I was given when I was given my diagnosis, 10 years ago, July 1989.
What is MG?
.......Myasthenia Gravis is a group of diseases, affecting the neuromuscular junction. Autoimmune MG happens when the body attacks itself, and may be caused by at least three known antibodies attacking different parts of the neuromuscular junction; congenital myasthenic syndrome (CMS, or CMG) is a "cousin" disease that is genetic in nature, meaning the body has a flaw in the chromosomes. MG is a chronic (incurable) disease deriving its name from Latin and Greek words meaning "grave muscle weakness." The resulting weakness of voluntary muscles improves with rest and worsens with activity. MG is not contagious, and only CMS may be passed from parent to child due to its genetic nature. There may be only a very slightly higher incidence of autoimmune diseases among children of myasthenics.
Causes
.......MG involves fluctuating levels of weakness of commonly used muscles. Weakness occurs when the nerve impulse does not adequately reach the muscle cells; this is caused by blockage of the action of neurotransmitters (the specific chemicals that transmit signals from nerve cell to muscle cell). Acetylcholine RECEPTORS on the muscles are actually destroyed by the immune system, thus it is an immune response of the body against itself (an autoimmune response). High levels of antibodies block the action of neurotransmitters.
......The cause of autoimmune disorders such as MG is unknown. In some cases, it may be associated with tumors of the thymus (a tissue of the immune system). It also may be associated with hyperthyroidism/thyrotoxicosis, rheumatoid arthritis, Lupus (systemic lupus erythematosus), and other immune system disorders. In many cases, no other disorder is identified.
......MG affects an estimated 3 out of 10,000 people. Except when the disorder is associated with thymus tumor (which is most common in elderly men), MG is most common in adult women, but can occur at ANY age. Symptoms may worsen or improve with pregnancy or menstrual periods.
Symptoms include:
vision changes:
double vision (diplopia)
difficulty maintaining steady gaze
eyelid drooping (ptosis)
swallowing difficulty (dysphasia),
frequent gagging or choking
difficulty chewing
difficulty talking
weakness or paralysis that worsens
with exertion later in the day
drooping head
poor posture
difficulty climbing stairs
difficulty lifting objects
need to use hands to arise from
sitting or recumbent positions
weakness or paralysis improves with
rest
Diagnosis
......During diagnosis the examination may be normal or may show muscle weakness that progressively worsens as the muscle is used. Reflexes and sensation are normal. Weakness may affect the arms; legs; the muscles for breathing, swallowing, talking, or any muscle group. Facial involvement is usually early, involving drooping eyelids.
Clinical:
......General
neurological strength and reflex testing is done by the physician. Timed
forward arm abduction and dynamometry of selected muscles is measured.
Electrodiagnostic:
EMG results vary. reference strategies
Various types of tests include RNS (repetitive nerve stimulation) and other
EMG testing.
Single Fiber EMG repetitive stimulation nerve conduction studies are more
productive (studies of
nerve impulse conduction, performed as the nerve supplying the muscles
is repeatedly stimulated).
Serological
(blood tests):
Acetylcholine
receptor antibodies (serum IgG) may be present in the blood, or the results
may be
sero-negative.
Pharmacological
(drug
tests):
Tensilon®, Enlon®, Reversol® (Edrophonium):A Tensilon test
is positive in most cases. A baseline
muscle strength evaluation is performed. After Tensilon; (a medication
that blocks the action of the
enzyme that breaks down the transmitter acetylcholine) is given, muscle
function improves
noticeably. There is a brief improvement in muscle strength after intravenous
injection, without
tongue spasms.
MRI and CT
scans are often done on the brain and chest to rule out differential diagnosis,
and to check
the thymus gland.
Pulmonary
function test (breathing tests)
Treatment / Therapy
......There is no known way to prevent or cure myasthenia gravis. However, treatment may result in prolonged periods of remission, without symptoms.
Anticholinesterates (AChE)
This will enhance neuromuscular
transmission. The first approach in treatment is to deal with the symptoms,
using anticholinesterates, (acetylcholinesterase inhibitors). They function
by blocking the enzyme (acetylcholinesterase) that normally breaks up acetylcholine
and allows the acetylcholine to be present for a longer period of time.
Thus results in improvement in skeletal muscle contraction. These medications
should be given 30 minutes before meals to maximize the ability to eat
and swallow.
Mestinon® or Regonol®
(Pyridostigmine bromide) available in tablet, slower acting capsule "Timespan"
(usually used at night), and syrup (for children, and those with severe
problems swallowing). Usual effective duration: 4 hours; Usual effective
range: 3-7 hours.
Prostigmin®, Methylsulfate
Min-I-Mix® (Neostigmine bromide; Atropine) usually reserved for
those who cannot use Mestinon, as it is an "older" drug. Known for causing
intestinal spasms and has even been used after surgery to get the bowels
to expel painful gas; not a side effect in all myasthenics. Usual
effective duration: 2 hours; Usual effective range: 1-4 hours
Mytelase® (Ambenonium
Chloride) It is rarely used anymore because of a very narrow therapeutic
window; that is there is little room for dosage mistakes before the patient
becomes toxic. USed more widely outside the US, some patients experience
better results than with more common treatment, such as Mestinon. Usual
effective duration: 6 hours; Usual effective range: 4-8 hours.
Ephedrine sulfate
A dose of 25
mg of ephedrine three times a day is usual and should be tried in every
patient.
Immunosuppresant drug therapy
(ISDT)
......This
will reduce the level of ACh receptor antibodies. The second approach is
to treat the CAUSE of the problem by trying to decrease the production
of the acetylcholine antibodies. One way this is done is by using drugs
which suppress the immune system. All immunosuppressive drugs have side
effects. Because these drugs suppress the body's immune system they are
at increased risk for developing infections.
Corticosteroid therapy
......These
lower the antibody production to the (nicotinic) cholinergic receptor,
which block the receptor. Thus, increase the number of available receptors
to interact with acetylcholine, which improves muscle strength. Takes 6-12
months for maximum effect.
Thymectomy
......Another
way to alter the production of acetylcholine antibodies is by surgically
removing the thymus gland, (thymectomy) which generates many of the antibodies.
This takes years to have an effect so this also is for long-term control
of MG. The removal may result in permanent remission for some people. The
thymus tissue is then evaluated for thymoma.
Prognosis
......There
is no cure, but long-term remission is possible. There may be minimal restriction
on activity in many cases. Pregnancy is possible but should be closely
supervised; the baby may require medications for a few weeks after birth
but usually does not develop the disorder.
......Advice
differs on the following: Dr. Henry Kaminski states that myasthenics may
NOT donate blood or organs, though the MGFA PA chapter states differently.
Myasthenics are not permitted to pilot aircraft unless given a special
dispensation; this is rare, but at least one USA Air Force pilot was granted
this.
......Myasthenics
should avoid extremes in temperature, such as hot tubs, as well as chemicals
which can interfere with the AcH, such as pesticides and insecticides.
Don't forget to check for complications/contraindications involved with
your particular prescriptions.
Complications
possible restrictions
on lifestyle and sexuality
side effects
of medications (See the specific medication.)
complications
of surgery
complications
of medication (steroids, immunosuppresants): e.g. sepsis, GI bleeding,
renal failure
Myasthenic or
Cholinergic crisis, may be life threatening. Crisis situations may occur
when muscle
weakness involves
the breathing muscles. Respiratory distress, respiratory failure and pneumonia
are
serious! Though
these attacks seldom last longer than a few weeks hospitalization and assistance
with
breathing may
be required.
Emergency management:
Go to the emergency room or call the local emergency number (such as 911)
if
breathing difficulty
occurs.
Survival
Medic Alert
The pamphlet said this information
are excerpt from:
Myasthenia Gravis - A Summary
James F. Howard, Jr., M.D., Department of Neurology, The University of
North Carolina at Chapel Hill
For a better understanding of this
condition go to the following site! It has more information you may
need or wish to investigate.
My
MG is not a Sports Car!
The Myasthenia
Gravis Web Ring is owned by
Daniel Freedman. This site part of The MG Ring is owned by Mary F. Jury. Want to join the Myasthenia Gravis Web Ring? Click Here to Help Fight MG! |
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