Myasthenia gravis

Myasthenia gravis is a rare autoimmune disease that affects your neuromuscular system. It causes a breakdown in communication between your nerves and muscles. Because of this, the muscles that you control become weak. These muscles include:

• muscles that move your eyes and eyelids
• face muscles
• muscles used for chewing, talking and swallowing
• muscles in your neck, arms and legs
• muscles used for breathing

Examples of muscles that myasthenia gravis does not affect include your heart muscle and the muscles in your blood vessels and gut.

Males and females from all ethnic groups can get myasthenia gravis. It’s most common in females younger than 40 years and males older than 60 years.

Symptoms of myasthenia gravis include:

• drooping of one or both of your eyelids
• blurred or double vision
• difficulty chewing or swallowing
• slurred speech
• weakness in your arms and legs — you may become unstable when you walk
• chronic (ongoing) muscle fatigue
• shortness of breath

Your symptoms can appear suddenly, or may take a few weeks to develop. Your muscle weakness can come and go.

Myasthenia gravis symptoms get worse when you are doing activity. They get better after you rest.

Your symptoms and how severe they are can be different for each person.

Myasthenia gravis is an autoimmune condition. This is when the body's immune system attacks its own healthy cells. In myasthenia gravis, the signals that your nerves send to your muscles are affected. As a result, your muscles cannot work well.

You are more likely to develop myasthenia gravis if a family member has it or if you have other autoimmune diseases or a problem with your thymus gland.

Other factors that may trigger myasthenia gravis include:

• an infection
• other illness
• extreme stress

If you are pregnant, and have myasthenia gravis, your baby has a higher chance of having a condition called neonatal (newborn) myasthenia. Neonatal myasthenia is a temporary weakness in a baby that usually starts in the first 1 to 2 days after birth. It may last for days or weeks, but sometimes it lasts longer.

A less common type of myasthenia gravis is congenital myasthenia. This inherited problem makes muscle signals weak and is not caused by the immune system. People are born with it, but symptoms might not appear until adulthood.

You should see your doctor if:

• you have symptoms of myasthenia gravis and have not been diagnosed
• you have a diagnosis of myasthenia gravis, and your symptoms are getting worse

Read about how to get the most out of your doctor's appointment.

Your doctor can diagnose myasthenia gravis by examining you and asking about your symptoms. They will send you to do some of these tests:

• Blood test — to check if you have antibodies that many people with myasthenia gravis have (called AChR antibodies).
• Ice test — your doctor covers your affected eye for 2 to 5 minutes with a cold pack, and checks if your eyelid droop gets better.
• Nerve conduction tests and electromyography — tests that measures your muscle function.
• Tensilon test — an injection of a medicine called edrophonium to check its effect on muscle strength.
• Imaging — chest x-ray, CT scan or MRI, to look for problems with your thymus gland

The process of a myasthenia gravis diagnosis can be long and frustrating. Many symptoms are general and similar to those of other illnesses. There is no single test that diagnoses myasthenia gravis, you may need to do many tests.

There is no cure for myasthenia gravis, but treatment can help manage your symptoms.

The treatment for myasthenia gravis depends on your symptoms. People with mild symptoms that don’t happen often usually don’t need any treatment.

Treatment for myasthenia gravis can include all or some of the following:

• medicines to improve your muscle strength or help balance your immune system — these include cholinesterase inhibitors, steroids and immunosuppressants
• surgery to remove your thymus gland, which is where your body produces the antibodies that attack your muscles
• a procedure called ‘plasmapheresis' that temporarily washes out abnormal antibodies from your blood and gives you normal antibodies from donated blood
• IVIG (also called intravenous immunoglobulin) — helps your immune system to work normally for a short time

You will be treated by a neurologist (a nerve specialist). Together, you can consider your medical history, symptoms and age to make the best treatment plan for you. This way you can make an informed decision.

Your doctor may also recommend therapies from allied health professionals to help you manage your symptoms and feel better in daily life. This can include speech therapists, physiotherapists and dietitians.

Treatment can often improve your muscle weakness, so it’s best to follow your neurologist's advice. Sometimes, it can help with symptom remission (where your muscle weakness improves and your doctor advises you to stop taking your medicines for a while).

If you have myasthenia gravis, try to lead a healthy and active lifestyle. Doctors recommend you look after yourself and to avoid possible triggers.

Triggers can include emotional stress, fever, exerting ('pushing yourself') too hard, some medicines and illness.

You may find it helpful to join a support group. You could meet people who are going through similar challenges and get tips from them.

You can wear medical alert jewellery such as a bracelet or necklace. It is a good idea to have a medicine card on you to alert others you have myasthenia gravis in case of emergency. It should include details such as your:

• name
• date of birth
• your doctor
• other medical conditions
• contact person in an emergency

Usually, having myasthenia gravis doesn't shorten your life. Treatment can also give you a good quality of life.

Exercising with myasthenia gravis

Ask your doctor to guide you on exercising, so that you continue to move within your limits. Do not exercise if you are weak. You may find it easier to exercise for short amounts of time with breaks, rather than longer sessions.

You may find it useful to keep a diary to note how your body responds to different activities and what kind of rest helps. This way, you can learn how to best use your energy.

It is important you discuss with your healthcare professional which exercise or movement is best for you. Ask your doctor if a referral to an exercise physiologist would help.

Taking new medicines

Before you take a new medicine check with your doctor to see if it's safe to take with myasthenia gravis. This includes:

• medicines another doctor prescribes
• over-the-counter medicines
• complementary medicines
• traditional remedies, such as Chinese traditional medicines

Myasthenia Gravis Alliance Australia (Opens in new tab) has resources on myasthenia gravis, including a patient tool kit (Opens in new tab) and links to peer support groups. You can also call the helpline on 1800 802 568.

Learn more about myasthenia gravis at:

• Myasthenia Gravis Association (Opens in new tab) of Queensland
• The Australian Myasthenic Association (Opens in new tab) in New South Wales

Visit Rare Voices Australia (Opens in new tab) for information for people living with rare and complex diseases.

Languages other than English

Visit Centre for Culture, Ethnicity & Health (Opens in new tab) for a guide available in many foreign languages explaining how to navigate and understand the Australian medical system (Opens in new tab).

Information for Aboriginal and/or Torres Strait Islander peoples

Rare Voices Australia (Opens in new tab) has helpful links for Aboriginal and Torres Strait Islander people who live with rare diseases.