MYASTHENIA GRAVIS FOUNDATION
We Offer Hope as Well as Help
The Myasthenia Gravis Foundation of California’s (MGFC) was founded in 1954. Its mission is
to find a cure for MG by funding cutting edge research and providing services for MG patients
through low cost (and, in some cases, free) MG Clinics, Drug Bank and patient support
auxiliaries throughout California and Nevada, as well as medical education, information and
What Is Myasthenia Gravis?
Myasthenia Gravis is a neurological disorder resulting in fluctuating weakness of the voluntary
muscle groups, such as those controlling the eyes, face, chewing, swallowing, and talking.
Muscles that control breathing and movement of the arms and legs can also be affected. The
weakness tends to increase with activity and improve with rest. For example, if you have MG,
you may notice during a meal, your jaw muscles become tired and weak, interfering with your
ability to chew food. After you have rested for a while, muscles may become strong again,
allowing you to resume eating.
This waxing-and-waning weakness of muscles, worsening with use and improving with rest, is a
hallmark of MG. Typically, there are periods when you notice more symptoms (called an
exacerbation) interspersed with periods when your symptoms decrease or disappear (called
The disease most commonly affects muscles that control eye and eyelid movement, so the first
symptom may be eyelid drooping and/or blurred or double vision. Many MG patients start out
with this “ocular myasthenia.” The majority go on to develop weakness in other muscles groups
within one or two years.
Myasthenia Gravis affecting multiple muscle groups throughout the body is called generalized
MG. Other common muscle groups to be affected may make it difficult to chew, swallow,
smile, shrug, life arms, grip, rise to a stand, or walk up stairs. When the muscles necessary for
breathing are affected, a patient is said to be in myasthenic crisis. This is a life-threatening
MG affects more than 30,000 Americans of all ethnic groups. The onset can occur at any age.
Women are most commonly affected during childbearing years, while men usually develop MG
in middle age. MG is not directly inherited, nor is it contagious.
Fortunately, effective treatments have been developed over the past few decades. Neurologists
can work with their patients to develop individualized treatments that allow most patients to lead
What Causes Myasthenia Gravis?
Under normal conditions, nerves direct muscles to work by sending a message through an area
called a receptor. The chemical that delivers the message is called acetylcholine. When
acetylcholine lodges in a nerve receptor, muscles know to contract. In Myasthenia Gravis, there
are fewer acetylcholine receptors than needed.
Myasthenia Gravis is considered to be an autoimmune disorder. In an autoimmune disease, the
body’s antibodies (cells that are supposed to be programmed to fight foreign invaders such as
bacteria, viruses or fungi) mistake a part of the body as foreign, resulting in its destruction. In
the case of MG, antibodies attach and destroy acetylcholine receptors needed for muscle
No one knows exactly what causes the body to begin producing antibodies that destroy
acetylcholine receptors. In some case, the process seems to be related to the thymus gland
which helps produce antibodies. About 15 per cent of all MG patients are found to have a
thymoma, a tumor of the thymus. Although most thymomas are benign, the thymus is usually
removed (thymectomy) to prevent potential spread of cancer. In fact, thymectomy seems to
improve symptoms of MG in some patients, even if no tumor is present.
Who Gets Myasthenia Gravis?
Estimates of the number of people affected by MG vary, ranging from five to 14 people per
MG occurs in all ethnic groups and both genders. It most commonly affects young adult women
(under 40) and older men (over 60), but it can occur at any age. Children sometimes develop
MG is not directly inherited nor is it contagious. Sometimes the disease may occur in more than
one member of the same family. If a woman with MG becomes pregnant, sometimes the baby
acquires antibodies from the mother and has MG symptoms for a few weeks or months after
birth. This is called neonatal myasthenia, and the symptoms can be treated.
In rare cases, myasthenia is caused by a defective gene and appears in infants born to non-
myasthenic mothers. This type is called congenital myasthenia.
What is the Role of the Thymus Gland in MG?
The thymus gland, found in the upper chest area beneath the breastbone, is a part of the body's
normal immune system. In most adults with MG, the thymus gland is abnormal. Some people
with MG develop thymomas or tumors on the thymus gland. Generally thymomas are benign,
but they can become malignant (cancerous). The relationship between the thymus gland and MG
is not yet fully understood.
What are the Signs and Symptoms of MG?
The muscles that control eye and eyelid movement, facial expression, and swallowing are most
often affected. The onset of the disorder may be sudden. Symptoms often are not immediately
recognized as MG.
In most cases, the first noticeable symptom is weakness of the eye muscles. In others, difficulty
in swallowing and slurred speech may be the first signs. While rare, first signs of MG can also
include difficulty with breathing. The degree of muscle weakness involved in MG varies greatly
among persons with this disease. Symptoms, which vary in type and severity, may include:
Drooping of one or both eyelids (ptosis)
Blurred or double vision (diplopia) due to weakness of the muscles that control eye movements
Unstable or waddling gait
Weakness in arms, hands, fingers, legs, and neck
Change in facial expression
Difficulty in swallowing and shortness of breath
Impaired speech (dysarthria)
Shortness of breath
How is MG Diagnosed?
Unfortunately, a delay in diagnosis of one or two years is not unusual in cases of MG. Weakness
is a common symptom of many other disorders. The diagnosis is often missed in people who
have mild weakness or in those whose weakness is restricted to only a few muscles.
The first steps of diagnosing MG include a review of the person's medical history and physical
and neurological exams. If the doctor suspects MG, several tests are available to confirm the
Antibody blood test. A special blood test can detect the antibodies that prevent nerves from
signaling to muscles. While most people with MG have abnormally high levels of these
antibodies, some individuals (about 10 percent) can actually test negative for antibodies. And,
antibodies may not be detected if only eye muscles are affected.
Edrophonium test. When this drug is injected, the weak eye muscles of people with MG will
briefly get stronger.
Nerve conduction test/repetitive stimulation. This is a test of specific muscle fatigue by repetitive
Single fiber electromyography (EMG). In this test, pairs of single muscle fibers are stimulated by
electrical impulses. It can detect impaired nerve-to-muscle transmission.
Computed tomography (CT) or magnetic resonance imaging (MRI). These tests can help
identify an abnormal thymus gland or a thymus gland tumor.
What is the treatment for MG?
Today, MG can be controlled. There are several therapies available to help reduce muscle
weakness. Most persons with MG have good results from treatment. In some people MG, like
many other autoimmune diseases, may go into remission (a period of time without symptoms)
and muscle weakness may disappear completely. Remission or improvement can occur without
treatment in some cases. According to the Muscular Dystrophy Association, up to 20 percent of
person with MG may have complete remission of symptoms without any treatment, and another
20 percent may improve without treatment. These spontaneous improvements are more likely to
occur during early stages of MG.
Treatment of MG may include:
Medications. Drugs used include cholinesterase inhibitors such as neostigmine and
pyridostigmine. These drugs help improve nerve signals to muscles and increase muscle strength.
Immunosuppressive drugs such as prednisone, cyclosporine, and azathioprine may also be used
to suppress the production of abnormal antibodies. They must be used with careful medical
followup because they can be associated with major side effects.
Thymectomy, the surgical removal of the thymus gland (which is abnormal in most persons with
MG). This surgery is done for persons with MG who have tumors, as well as for individuals
without tumors. It improves symptoms in more than half of individuals without tumors. It may
cure some people with MG, possibly by re-balancing the immune system.
Other therapies sometimes used to treat MG during especially difficult periods of weakness
Plasmapheresis or plasma exchange. This is a procedure that removes abnormal antibodies from
High-dose intravenous immune globulin. This treatment temporarily interferes with the ability of
the immune system to damage the nerve muscle junction. Treatment options for a person with
MG depend on the severity of the weakness, which muscles are affected, and the person's age
and other medical problems.
In a few cases, MG may cause severe weakness resulting in acute respiratory failure. But most
people can expect to lead normal or nearly normal lives.
What is a myasthenic crisis?
A myasthenic crisis occurs when weakness affects the muscles that control breathing. This can
create a medical emergency requiring a respirator to help the person breathe or measures to
prevent a person from taking in, or aspirating, too much air into their lungs. In individuals whose
respiratory muscles are weak, infection, fever, a reaction to medication, or emotional stress can
trigger a crisis.
How can I help take care of myself if I have MG?
You can follow a few simple steps to help cope with the condition in your daily life. Plenty of
rest and a well balanced, potassium-rich diet can help ease fatigue. Good sources of potassium
include oranges, orange juice, and bananas. It is important to avoid overexertion, and if
necessary, to rest the eyes or to lie down briefly a few times a day.
Drugs That May Aggravate MG
Decisions about whether or not to take a drug must be made in consultation with your doctor. It
should also be emphasized that while these drugs may make the symptoms of MG worse, none
of them affects the basic disease process, apart from penicillamine.
From the doctor's viewpoint, problems arise because information on the drugs, in reference
books as well as in the packaging, is often inaccurate. Some drugs, temazepam being a good
example, are labeled as being absolutely contra-indicated in MG, when in fact they do not affect
it at all, while on the other hand, some drugs which commonly aggravate MG do not carry a
warning. Further problems arise for doctor and patient, because of the profusion of available
drugs. For example, no fewer than 15 different "beta-blockers" are licensed for use in the UK,
and any one of these may be marketed by several companies under different brand names.
Below drugs are listed according to their class, and provided both "official" name, in bold, and
trade names, where these are different, in italic. Popular mixtures which contain the offending
drug are listed (in brackets). There is a brief outline of how they may affect MG. As well as
tablets and injections, preparations used locally in the eye are listed, as significant amounts of
drug can be absorbed into the bloodstream when given by this route.
Also, beware of laxatives, which can impair the absorption, and therefore the effectiveness, of all
your drugs, but particularly of pyridostigmine (mestinon).
These are used to treat and prevent irregular heart beat. The ones in this list have largely been
superseded by newer, safer, drugs, including beta-blockers (see below).
Procaine Amide Pronestyl
Quinidine Kinidin Durules
These are used to prevent and treat bacterial infections. One group (A), which contains six
members, affects transmission between nerve and muscle, and therefore can make MG worse.
They are chiefly given by injection, and you are therefore most likely to come across them in
hospital. You are more likely to encounter those in groups B, which are usually given as tablets,
often for chest infections, but which are much less likely to upset your MG, and C, which are
commonly used for bladder and kidney infections. Group D is now used very rarely.
Group E (one member) are antibiotics which have been shown to have serious side effects , and
which must not be prescribed to myasthenics.
Gentamicin Genticin, Genticin Ear/Eye drops, Cidomycin Injection, Cidomycin Ear/Eye
Tetracycline Achromycin, Sustamycin, Tetrabid, Tetrachel, Deteclo, (Mysteclin).
Doxycycline Nordox, Vibramycin,
Limecycline Tetralysal 300
Minocycline Minocin MR
Nalidixic Acid Mictral, Negram, Uriben
Colistin Colomycin Injection
These drugs are sometimes also used to treat rheumatic conditions.
Chloroquine Avloclor, Nivaquine
4. ANTI-RHEUMATIC DRUGS
Penicillamine Distamine, Pendramine.
These drugs, which are used to relax and reduce the activity of the bladder and bowels, act by
opposing the action of acetyl-choline (whereas drugs like mestinon promote it), and therefore
carry a warning against their use in patients with MG. In fact, theoretically, they should not
interfere with the action of acetyl-choline on muscle, and in practice there have been no reports
of adverse effects in MG - perhaps because the warning has been so effective!
Oxybutinin Cystrin, Ditropan
These drugs are used for the treatment of angina and other forms of heart disease, high blood
pressure, migraine, and, occasionally, anxiety. They commonly produce a feeling of fatigue or
muscle weakness, which tends to improve with continued treatment, and, rarely, have been
reported to induce MG.
Propranolol Inderal, Angilol, Apsolol, Bedranol, Berkolol, Beta-Prograne, Cardinol, Propanix,
Atenolol Tenormin (Tenif, Tenoretic, Tenoret 50, Co-Tenidone), Atenix, Antipressan, Kalton,
Totamol, (Beta-Adalat, Co-Tenidone, Totaretic)
Acebutolol Sectral (Secadrex)
Bisoprolol Emcor, Monocor, (Monozide)
Metoprolol Betaloc, Lopresor, (Co-Betaloc)
Oxprenolol Trasicor, (Trasidrex)
Pindolol Visken, (Viskaldix)
Sotalol Beta-Cardone, Sotacor, (Sotazide, Tolerzide)
Timolol Betim, Blocadren, (Moducren, Prestim, Timoptol Eye-drops).
7.DRUGS USED IN EPILEPSY
This is always listed among drugs which can precipitate MG, but actual reports of problems are
8. DRUGS USED IN PSYCHIATRY
A. Chlorpromazine and related drugs. These drugs are used in a wide variety of conditions. The
original members of the group, chlorpromazepine and promazine, were reported to aggravate, or
even to precipitate MG, but there are now a lot of newer analogues, and reports of trouble from
these are rare. However it is probably still wise to use them cautiously.
Sulpiride Dolmatil, Sulpitil
Zuclopenthixol Clopixol Acuphase
B. Lithium Camcolit, Liskonum, Li-liquid, Litarex, Priadel.
Tranylcypromine Parnate, (Parstelin)
9. MUSCLE RELAXANTS
These drugs are designed to cause muscle paralysis and are used almost exclusively by
anaesthetists. There are two classes of muscle-relaxants: curare-like drugs, which must not be
used in MG, and depolarising relaxants, which can sometimes be used. Both types must be
distinguished from drugs such as the minor tranquillisers, which are often called "muscle-
relaxants", although their effects are entirely non-specific.
Is MG associated with other conditions?
Since it is an autoimmune disease, it may occur in combination with other autoimmune
conditions such as rheumatoid arthritis, Sjorgrens syndrome, lupus, pernicious anemia, or
What Research is Being Done?
Much has been learned about Myasthenia Gravis in recent years. Technological advances have
led to more timely and accurate diagnosis, and new and enhanced therapies have improved
management of the disorder. Much knowledge has been gained about the structure and function
of the neuromuscular junction, the fundamental aspects of the thymus gland and of
autoimmunity, and the disorder itself. Despite these advances, however, there is still much to
learn. The ultimate goal of Myasthenia Gravis research is to increase scientific understanding of
the disorder. Researchers are seeking to learn what causes the autoimmune response in
Myasthenia Gravis, and to better define the relationship between the thymus gland and
Today's Myasthenia Gravis research includes a broad spectrum of studies conducted and
supported by NINDS. NINDS scientists are evaluating new and improving current treatments for
the disorder. One such study is testing the efficacy of intravenous immune globlin in patients
with MG. The goal of the study is to determine whether this treatment safely improves muscle
strength. Another study seeks further understanding of the molecular basis of synaptic
transmission in the nervous system. The objective of this study is to expand current knowledge
of the function of receptors and to apply this knowledge to the treatment of Myasthenia Gravis.
MG patients frequently take costly medications in order to keep their symptoms in check. In
many cases, health insurance does not cover the cost of these drugs.
Through our Drug Bank Program, MGFC is able to offer patients the chance to purchase life-
saving MG medications at low cost. Because grant funds are received to subsidize this program,
the Drug Bank is restricted to MG patients residing in California and Nevada. The Drug Bank
operates as a mail order service. Because medications are only shipped once a week from
Glendale Medical Pharmacy, it is suggested patients keep an ample supply of medications on
hand (3-4 weeks).
To request a Drug Bank Application form, call the Myasthenia Gravis Foundation of California
at (800) 574-7884 (800) 574-7884 or (323) 887-0056 (323) 887-0056 or email:
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If you have moved, please inform the MGFC office so that you can receive your newsletter on a
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used for research or valuable patient services. To change your address, please email:
firstname.lastname@example.org or call (toll-free) (800) 574-7884 (800) 574-7884 . Thank you.
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