Myasthenia gravis is an autoimmune disease where your own antibodies attack and destroy nerve-muscle connections, leading to muscle weakness. Myasthenia gravis, otherwise known as MG, is a relatively rare condition that has been known to affect approximately 20 in 100,000 people. In the United States, the number of people affected by MG is around 60,000.

Myasthenia Gravis – What is it?

Myasthenia gravis is a type of neuromuscular disorder that will cause muscle weakness. Typically, this condition will affect the muscles that you can normally control consciously. As such, the types of muscles that are commonly affected are:

• Eyelids
• Eye movement
• Breathing
• Swallowing
• Facial muscles
• Shoulder muscles

In general, the muscle weakness that is experienced by the affected individual will tend to get worse with activity, but only  temporary. On the other hand, the weakness will tend to improve with some rest.

Myasthenia gravis is an autoimmune condition, wherein your own immune system will mistakenly attack your body’s connection between the nerves and the muscles. When you have myasthenia gravis, your muscle cells will have issues responding to the nerve impulses, which in normal cases will stimulate them to contract. This would lead to muscle weakness.

As of now, there’s no cure for MG. But, with available treatments, you can control your symptoms, which will often allow the victims to lead a quality life. Moreover, myasthenia gravis will not decrease someone’s life expectancy.

Myasthenia Gravis – What causes it?

It is caused by a flaw in the passage of nerve impulses to your muscles. This happens when the normal link between the nerves and the muscles is disrupted at the neuromuscular junction. In normal cases, nerves will direct your muscles by sending messages through receptors. As such, the chemical that carries the message is known as acetylcholine. In the myasthenia gravis, these acetylcholine receptors are fewer in numbers. This means that antibodies of your own immune system will destroy the acetylcholine receptors. However, the underlying cause of this autoimmune response is still unknown.

Myasthenia Gravis – What are the signs and symptoms?

In a majority of cases, the onset of the condition will be sudden and the signs and symptoms cannot be immediately identified as myasthenia gravis. Often, the first symptom to be noticed is the weakness of the muscles in your eyes. In some people, slurred speech and issues with swallowing will be the first symptoms.

The common symptoms of myasthenia gravis are:

• Drooping of one/both eyelids
• Blurred vision
• Double vision
• Changes in facial expression
• Difficulty swallowing
• Shortness of breath
• Distorted speech
• Weakness of:
  • Arms
  • Hands
  • Fingers
  • Legs
  • Neck

The severity of muscle weakness due to MG will differ from one person to another.

Myasthenia Gravis – Who gets it?

Literally, this condition can affect anyone, be it, men or women. Also, it can occur across all races and ethnicities. The most common victims are found to be women below 40 years old and men over 60 years old. However, it can start at any age, for example, juvenile myasthenia gravis.

MG is not found to be hereditary or contagious. But, neonatal myasthenia can also be possible. Here, the fetus will acquire antibodies from the mother with the condition. However, this will be temporary and usually disappear in 2 or 3 months after childbirth. In very rare cases, the child of a healthy mother will develop congenital myasthenia. This cannot be considered as an autoimmune disorder, although it could cause symptoms similar to myasthenia gravis.

Myasthenia Gravis – How is it diagnosed?

A physician may order one or more tests to confirm that you have myasthenia gravis. The diagnostic procedures include:

• A physical examination
• A neurological examination
• An edrophonium test
• A blood test
• Electrodiagnostics
• Diagnostic imaging
• Pulmonary function testing

As weakness is common to several other disorders, the whole diagnoses will be delayed, up to 2 years.

Myasthenia Gravis – How is it treated?

There are several treatment options available to help decrease the symptoms and improve weakness associated with myasthenia gravis. Some of the common treatment options include:

• Thymectomy:
  • A surgery to remove the thymus gland.
• Anticholinesterase medications:
  • Mestinon
  • Pyridostigmine
• Immunosuppressive drugs:
  • Prednisone
  • Azathioprine
  • Mycophenolate mofetil
  • Tacrolimus
  • Rituximab
• Plasmapheresis:
  • A treatment procedure to remove harmful antibodies from plasma and to substitute them with good ones.
• Intravenous immunoglobulin:
  • A highly concentrated injection containing antibodies.

Myasthenia Gravis – What’s the prognosis?

Most people with myasthenia gravis can remarkably improve their weakness and lead normal lives. However, in cases of severe weakness, it can cause a respiratory failure that needs immediate medical attention.