Myasthenia gravis

Treating myasthenia gravis

Treatment for myasthenia gravis can significantly improve symptoms ofmuscle weakness and many people with the conditionare able to lead a relatively normal life. However, severe or chronic symptoms frequently require long-term treatment.

If symptoms aremild, many people find that getting plenty of rest helps improve their symptoms without the need for additional treatment.

Medication

Medicines such as pyridostigmine ,an acetylcholinesterase inhibitor, prevent the breakdown of acetylcholine, an important chemical thathelps themuscles contract (tighten).

These medicines tend to work best in mild myasthenia gravis. They can improve muscle contractions and strength in affected muscles.They're often usedif the initial symptoms aren't too severe but pyridostigmine isn't a suitablelong-term treatment for most people.

However, they can cause side effects, such as stomach cramps, muscle twitching, Traveller's diarrhoea and nausea. Other medications may be prescribed to counteract these side effects.

If initial treatment withpyridostigmine isn't effective, or only suitable for temporary use, then steroid tablets, such as prednisolone, are used at a low dose. The dose can be increased gradually over time and is usually kept at a high dose for several months until remission is achieved.

Immunosuppressant medication may be prescribed if remission isn't achieved or the high dose of prednisolone isn't suitable. This is usually azathioprine , mycophenolate ormethotrexate. These are used to help achieve remission so the prednisolone dose can be reduced and eventually stopped.

Your blood will have to be regularly monitored when taking immunosuppressants, which may take at least a year to take full effect.

If long-term remission is achieved over time (usually years), it may be possible to stop all immunosuppressant medication.

Thymectomy

In some cases ofmyasthenia gravis, surgery to remove the thymus gland (a thymectomy) may be recommended.

In some studies, thymectomy has been shownto improve the symptoms of people who don't have tumours (thymomas) on their thymus gland.The improvement often happens within the first few months, although continued benefit may be seen for up to two years after surgery. Nowadays, the thymus gland is usually removed using keyhole surgery.

The current recommendations for people under 45 years old, with general symptoms of myasthenia gravis, no thymomasand have had the illness for less than two years, thymectomy gives:

a 25% chance of remission
a 50% chance of improvement of symptoms, still requiring long-term immunosuppression
a 25% chance of no benefit

A thymectomy often has little effect on the symptoms of myasthenia gravis for people with thymomas. However, removal is often recommended to avoid complications caused by the tumour spreading in the chest.

Plasmapheresis and immunoglobulin therapy

Plasmapheresis or intravenous immunoglobulin therapy may be needed in very severe cases of myasthenia gravis, where a person's muscle weakness is causing life-threatening breathing or swallowing problems.

These treatments are given in hospital and involve:

plasmapheresis your blood is circulated through a machine that removes the plasma containing some of the harmful antibodies
intravenous immunoglobulin therapy injections of normal immunoglobulin, taken from healthy donated blood,that temporarily change the way your immune system operates

Both treatments can improve the symptoms of myasthenia gravis , but the benefits usually only last a few weeks. They aren't suitable as long-term treatments for myasthenia gravis, and are usually only used to treat people who are seriously ill.