What is a myasthenic crisis in a patient with myasthenia gravis, and why does it require emergency treatment?

A myasthenic crisis is a life-threatening medical emergency that occurs in some patients with myasthenia gravis, characterized by severe weakness of voluntary muscles, particularly those responsible for breathing and swallowing [1]. This weakness requires urgent medical intervention, and the patient may require respiratory support using a mechanical ventilator [2].

This crisis occurs when the immune system mistakenly attacks healthy cells or proteins necessary for normal muscle function, which hinders the transmission of nerve signals to the muscles and prevents them from contracting effectively [2]. A myasthenic crisis can be exacerbated by factors such as infection, stress, surgery, or an adverse reaction to certain medications [2].

Symptoms of Myasthenic Crisis and Warning Signs

The primary symptoms of a myasthenic crisis include severe weakness of the respiratory muscles, leading to shortness of breath and difficulty speaking [1]. The patient may also notice extreme difficulty swallowing, which increases the risk of choking or food and liquids entering the lungs [1]. It is crucial to pay attention to any sudden worsening of muscle weakness, especially if it affects the ability to breathe or swallow. Approximately 15-20% of people with myasthenia gravis experience at least one myasthenic crisis during their lifetime [2].

Why does a myasthenic crisis require emergency treatment?

A myasthenic crisis is considered a medical emergency because it directly threatens vital body functions, especially breathing. If not treated quickly, it can lead to total respiratory failure and grave outcomes [2]. Immediate medical intervention is essential to support breathing and restore muscle function.

Emergency treatment options for myasthenic crisis

Several treatments are used in cases of myasthenic crisis to reduce the impact of harmful antibodies and restore muscle strength. These treatments include [2]:

• Plasma Exchange (Plasmapheresis): A medical procedure in which plasma containing harmful antibodies is removed from the blood and replaced with healthy plasma or substitute fluids [1].
• Intravenous Immunoglobulin (IVIg): Concentrated injections of antibodies collected from healthy donors, which can modulate the immune system's response [1].

These treatments are usually effective for a few weeks or months [1]. Immunosuppressive medications may also be used in some cases to help suppress the production of abnormal antibodies [2].

Practical steps for patients and caregivers

Patients with myasthenia gravis and their caregivers must be fully aware of the symptoms of a myasthenic crisis. If any signs of severe respiratory weakness or difficulty swallowing appear, emergency medical help must be sought immediately [2]. It is also helpful for the patient to have a clear emergency plan with their attending physician. To learn more about myasthenia gravis in general and available treatment options, you can visit Myasthenia Gravis: How Autoimmunity Affects Muscles and Treatment Options (Arabic).

Medical references

• Myasthenia Gravis
• Myasthenia Gravis