Myasthenia gravis

Myasthenia gravis is a rare, chronic autoimmune disease in which people develop antibodies against transmembrane proteins of the neuromuscular junction, most commonly the acetylcholine receptor or muscle-specific tyrosine kinase. This results in fluctuating muscle weakness and fatigue, and people with the condition may experience myasthenic crises, in which rapid and severe worsening of symptoms can be life-threatening.

How prevalent is myasthenia gravis?

Myasthenia gravis is a rare disease, estimated to occur in only 150 to 200 people per million.

Who is most at risk?

Women are more likely to develop myasthenia gravis up to the age of approximately 50 years, whereas men more often develop it when they are older.

Which conditions can be confused with myasthenia gravis?

People with other disorders of the neuromuscular junction, such as Lambert–Eaton syndrome, botulism, and tick paralysis, present with similar symptoms to myasthenia gravis. Other conditions that may simulate myasthenia gravis include acute inflammatory demyelinating polyradiculoneuropathy, mitochondrial neuromuscular disorders, and motor neuron disease.

The picture is further complicated in older adults, in whom symptoms such as dysphagia, fatigue, and slurred speech can be ascribed to a large number of age-related conditions, and indeed simply to older age in the case of signs such as ptosis.

How does myasthenia gravis impact people with the disorder?

People with myasthenia gravis, particularly those with treatment-refractory disease, experience symptom exacerbations, myasthenic crises, and may require hospitalization. Treatment itself creates a burden, with people reporting medication side effects such as tiredness, weight gain, and mood swings. Compared with the general population, people with myasthenia gravis report poorer physical functioning, emotional wellbeing, and health-related quality of life.