Myasthenia Gravis (MG) What is myasthenia gravis? Thymus

Myasthenia gravis (MG) is an autoimmune disorder, which means it is caused by the body mistakenly attacking itself. In this case, the body blocks signals sent by the nerves to the muscles that normally prompt the muscles to move. Because the muscles don’t “receive” the signals, they can’t move, and grow increasingly weaker. Muscle weakness may grow severe over time, making this a potentially serious condition.

Research suggests that the thymus gland, located behind the breastbone, may play a role in some cases of myasthenia gravis. The thymus produces immunity-boosting proteins called antibodies, and it is possible that these antibodies mistakenly attack receptors in the muscles that normally respond to a specific chemical and obey nerve signals saying, “Move.”

What are the symptoms of myasthenia gravis?
  • Muscle weakness that increases with use or exercise, and improves after resting those muscles
  • Weakness of the muscles that control the eyelids, eye movement, facial expression, chewing, swallowing, coughing, breathing, arm and leg movement
  • Drooping eyelids
  • Double/blurred vision
  • Difficulty swallowing, speaking and walking
  • Weakness of the hand muscles
  • Myasthenic crisis—during a severe flare-up of symptoms, breathing can become very difficult
What are the risk factors for myasthenia gravis?

Myasthenia gravis (MG) may be inherited as a genetic disease. However, the disorder may develop spontaneously later in life. In adults, myasthenia gravis may occur at any age, although symptoms begin to appear more often between the ages of 20 to 30 in women and between the ages of 50 to 60 in men.

What tests can I expect?

Your doctor will probably refer you to a neurologist, an expert in diseases of the nervous system. Tests may include:

  • Blood tests to identify the presence of abnormal antibodies and look for thyroid disease, which is more common in people with myasthenia gravis (MG)
  • Electromyography (EMG) tests to reveal abnormal muscle function
  • Repetitive nerve stimulation to look for gradually increasing muscle weakness during the test
  • Genetic tests
  • CT or MRI scan of the chest, to look for a tumor of the thymus gland
  • Pulmonary function test to judge how myasthenia gravis (MG) may be affecting your ability to breathe
What are my treatment options?

There is no cure for myasthenia gravis (MG). This is a lifelong condition and treatment focuses on the management of symptoms. Medication is often the first course of treatment along with immunosuppressive therapy to suppress the immune system, so fewer antibodies attack the receptors on your muscles, enabling them to respond normally.

Immunoglobulin therapy and plasmapheresis (a procedure to clean the blood of abnormal antibodies) is also used to reduce symptoms.

Physical and occupational therapy: This doesn’t alter the course of the disease, but rather, it helps you cope with changes in muscle strength. You’ll learn alternative ways to approach daily activities.


The thymus gland is an essential organ in the development and maturation of immune function early in life. Thymectomy is an operation to remove the thymus gland in patients with myasthenia gravis (MG), which leads to significant remission of the disease in more than 80% of patients. Our thoracic surgeons performed the world's first complete endoscopic robotic thymectomy for myasthenia gravis using the da Vinci® Robotic Surgical System. Endoscopic thymus surgery with the da Vinci robot enables a complete and extended resection of all the thymic tissue in the mediastinum and neck.

We are one of only a few centers in the US that can also offer transcervical thymectomy (a procedure in which the thymus is removed through a small incision in the lower part of the neck). Due to minimal surgical trauma of both of these minimally invasive techniques, patients can return to full activity in a very short time.

For an Appointment Call
Raja Flores
Andrew J. Kaufman, MD
Chief, Department of Thoracic Surgery
Daniel Nicastri
Ram Reddy
Dong-Seok Lee
Henry Tannous
Andrea Wolf

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