How common is myasthenia gravis?

Myasthenia gravis is an autoimmune condition that causes skeletal muscle weakness. These are the muscles that connect to your bones and help you move. Myasthenia gravis usually targets the muscles in your eyes, face, neck, arms and legs. It can affect your ability to:

• Move your eyes or blink.

• Keep your eyes open.

• Make facial expressions.

• Chew, swallow and talk.

• Raise your arms up and lift objects.

• Walk upstairs or get up from a chair.

Muscle weakness gets worse after physical activity and improves after rest. Symptoms usually happen quickly.

Myasthenia gravis is a chronic (long-lasting) neuromuscular condition (it affects the junction between your nerves and muscles). There isn’t a cure, but effective treatment can help you manage your symptoms and function well.

What are the types of myasthenia gravis?

The types of myasthenia gravis include:

• Autoimmune myasthenia: It’s an autoimmune condition where the cause isn’t well understood but the likely cause is the production of certain types of antibodies (immune system proteins). This is the most common type.

• Neonatal myasthenia: A fetus gets certain antibodies from the birthing parent who has myasthenia gravis. An infant may have a weak cry or sucking reflex at birth. These temporary symptoms usually go away after three months.

• Congenital myasthenia: It isn’t an autoimmune condition, and a genetic change causes this type.

There are two subtypes of autoimmune myasthenia:

• Ocular: The muscles that move your eyes and eyelids weaken. Your eyelids may droop, or you may not be able to keep your eyes open. Some people have double vision. Eye weakness is often the first sign of myasthenia. Ocular myasthenia gravis may evolve into the generalized form for nearly half of all people diagnosed with this type.

• Generalized: Muscle weakness affects your eye muscles and others in your face, neck, arms, legs and throat. You may find it difficult to speak or swallow, lift your arms over your head, stand up from a seated position, walk long distances and climb stairs.

Initial symptoms of myasthenia gravis happen suddenly. Your muscles usually get weaker when you’re active. Muscle strength returns when you rest. The intensity of muscle weakness often changes from day to day. Most people feel strongest at the start of the day and weakest at the end of the day.

In rare instances, myasthenia gravis affects muscles in your respiratory system. You may have shortness of breath or more serious breathing problems. Contact 911 or your local emergency services number if you have trouble breathing. In general, this doesn’t occur suddenly.

What causes myasthenia gravis?

Myasthenia gravis (autoimmune type) happens when your body’s immune system mistakenly attacks itself. Researchers aren’t sure why this happens. Studies suggest that certain immune system cells in your thymus gland have trouble identifying what’s a threat to your body (like bacteria or viruses) versus healthy components.

A genetic change causes congenital myasthenia. Antibodies passed from a birthing parent to a fetus during pregnancy cause neonatal myasthenia. – Source: ClevelandClinic.org

Did you know?

Rare

In rare instances, pregnancy brings on myasthenia gravis symptoms for the first time.

STATS

How can I alleviate myasthenia gravis symptoms?

If you have myasthenia gravis, try these steps to ease fatigue and boost muscle strength:

• Exercise regularly to strengthen muscles, boost your mood and give you more energy. Talk to your healthcare provider before starting an exercise program to make sure it’s safe.

• Avoid going outside in the middle of a hot day. Apply cold compresses to your neck and forehead when you feel overheated. Heat can make your symptoms worse.

• Get plenty of protein and carbohydrates in your meals for added energy.

• Tackle your most exhausting tasks earlier in the day when you feel your best.

• Take naps or rest breaks throughout the day.