Myasthenic crisis: breathing and swallowing emergencies in myasthenia gravis

Myasthenia gravis is a long-term autoimmune condition in which the immune system damages the communication system between the nerves and muscles, making muscles weak and easily tired. The NHS says it most commonly affects the muscles that control the eyes and eyelids, facial expressions, chewing, swallowing and speaking, but can affect most parts of the body.

It is a condition that typically has phases when it improves and phases when it gets worse. A myasthenic crisis is the most serious form of worsening. The NHS describes it as a period in which symptoms suddenly get worse, for example severe breathing or swallowing problems.

The NHS lists the symptoms of weakness in the muscles of the mouth, throat and chest, which are the ones that become dangerous in a crisis. The symptoms generally tend to be worse when you are tired and in some people can have other triggers, such as stress, infections and certain medicines.

• Shortness of breath, particularly when lying down or after exercise, or worsening breathlessness.

• Difficulty swallowing, choking or accidentally inhaling bits of food, which can lead to repeated chest infections.

• Slurred or quiet speech and difficulty chewing.

• Difficulty holding your head up, with weak neck, arms or legs.

• Severe breathing or swallowing difficulties that are getting worse.

The NHS says to call 999 for an ambulance immediately if you have worsening severe breathing or swallowing difficulties. Do not wait for symptoms to settle, and do not drive yourself.

If you have myasthenia gravis, it helps to carry information about your condition and medicines, such as a card or a list, so that ambulance and hospital staff know you have the condition. The sources used here do not describe this specifically, but it is a sensible step; your neurologist or the MG charity can advise.

The NHS says that these potentially life-threatening symptoms require urgent treatment in hospital, which may include oxygen through a face mask, using a breathing machine (ventilator), intravenous immunoglobulin therapy, a treatment made from donated blood that improves muscle strength by temporarily changing how your immune system works, and plasmapheresis, where your blood is circulated through a machine that filters out the harmful antibodies attacking the communication system between nerves and muscles.

The NHS says the treatment is given in hospital. The sources used here do not describe what happens afterwards, so questions about longer-term treatment are best put to your neurology team.

The NHS says that some people find things such as tiredness and stress make their symptoms worse, and that symptoms can also be triggered by infections and certain medicines. It advises avoiding anything that triggers the symptoms as part of long-term care.

Because infections and some medicines can make myasthenia gravis worse, anyone with the condition should always tell doctors, dentists and pharmacists that they have it before taking a new medicine. People should check with their specialist team before starting new medicines.

The NHS says treatments to keep symptoms under control include avoiding triggers, medicine to improve muscle weakness and surgery to remove the thymus gland. It describes myasthenia gravis as a long-term condition with flare-ups followed by periods of remission, and notes that while remission can sometimes be permanent, this is rare.

The NHS states that if severe it can be life-threatening but it does not have a significant impact on life expectancy for most people. Regular review with a neurologist is part of keeping symptoms controlled and reducing the chance of a crisis.

A myasthenic crisis is managed through NHS ambulance and emergency services, with intensive care and neurology teams in hospital. The NHS also says clinical teams pass information on people with myasthenia gravis to the National Congenital Anomaly and Rare Disease Registration Service, from which you can opt out at any time.

Private neurology consultations are available for second opinions, but a crisis is always an emergency that needs the NHS 999 route. The NHS points people with the condition to local and national support groups.