Myasthenia Gravis

Diagnosis

Your healthcare professional begins by discussing your symptoms, reviewing your medical history, and performing a physical examination. A neurological exam is also done to evaluate how well your nerves and muscles are working together.

During the neurological exam, your healthcare professional may assess:

• Reflexes

• Muscle strength

• Muscle tone

• Senses of touch and sight

• Coordination

• Balance

Several additional tests may be used to confirm a diagnosis of myasthenia gravis.

Ice pack test
If you have a drooping eyelid, your healthcare professional may place a bag of ice on the eyelid for about two minutes. After removing the ice, the eyelid is checked to see whether the drooping has improved.

Blood test
Blood tests may detect antibodies that interfere with the receptors where nerves communicate with muscles, preventing normal muscle movement.

Repetitive nerve stimulation
In this nerve conduction study, electrodes are placed on the skin over specific muscles. Small electrical pulses are sent through the nerve to measure how well it communicates with the muscle. The test is repeated to see if the muscle response weakens with repeated stimulation, which may suggest myasthenia gravis.

Single-fiber electromyography
This test measures electrical signals between nerves and muscles. A thin wire electrode is inserted into a muscle to examine the activity of individual muscle fibers. Abnormal results can help confirm the diagnosis.

Imaging tests
A CT scan or MRI may be ordered to check the thymus gland for enlargement or tumors, known as thymomas.

Pulmonary function tests
These tests measure lung function to determine whether myasthenia gravis is affecting breathing muscles.

Treatment

Treatment for myasthenia gravis is tailored to each person based on age, symptom severity, and how quickly the disease is progressing. Treatments may be used alone or in combination to control symptoms.

Medicines
Cholinesterase inhibitors
Medicines such as pyridostigmine improve communication between nerves and muscles. While they do not cure the condition, they may increase muscle strength and contraction. Possible side effects include stomach upset, diarrhea, nausea, and increased saliva or sweating.

Corticosteroids
Medicines such as prednisone suppress the immune system and reduce antibody production. Long-term use can cause side effects such as bone thinning, weight gain, diabetes, and increased risk of infection.

Immunosuppressants
Other immune-suppressing medicines may be prescribed, including azathioprine, mycophenolate mofetil, cyclosporine, methotrexate, or tacrolimus. These medicines may take several months to work and are often used along with corticosteroids. Serious side effects may include infection and liver or kidney damage.

Intravenous therapy
Some therapies are usually given for short periods, especially during symptom flare-ups or before surgery.

Plasmapheresis
This procedure filters antibodies from the blood using a machine similar to dialysis. The benefits typically last only a few weeks. Risks include low blood pressure, bleeding, heart rhythm problems, muscle cramps, and allergic reactions.

Intravenous immunoglobulin
This treatment supplies healthy antibodies to alter the immune response. Benefits usually appear within a week and may last several weeks. Side effects are generally mild and may include headache, chills, dizziness, and fluid retention.

Rituximab
This intravenous treatment targets B-cells involved in antibody production. It is generally used when other treatments do not work and may cause serious side effects.

Neonatal Fc receptor blockers
These medicines reduce harmful antibodies in the body by blocking the neonatal Fc receptor. Common options include:

• Efgartigimod, given weekly for four weeks by IV or injection

• Rozanolixizumab, given weekly by IV for six weeks

Other therapies
Molecular therapies target specific parts of the immune system, including the complement system. These may include:

• Eculizumab and ravulizumab, given by IV at regular intervals, with precautions to prevent meningococcal infection

• Zilucoplan, a daily injection that can be used at home

Newer treatments, including therapies that speed up antibody breakdown and CAR T-cell therapy, are being studied. Research is ongoing to determine their long-term effectiveness and safety.

Surgery
Some people with myasthenia gravis have tumors of the thymus gland. Surgical removal of the thymus, called thymectomy, is usually recommended if a tumor is present.

Even without a thymus tumor, thymectomy may improve symptoms, although benefits may take years to appear. Surgery can be performed as open surgery or using minimally invasive techniques.

Minimally invasive approaches may involve video-assisted or robot-assisted methods with smaller incisions, less pain, and shorter recovery times. The choice of surgery depends on the thymus condition, presence of a tumor, and overall health.

Treatment plans are regularly reviewed and adjusted to help control symptoms, preserve muscle function, and improve quality of life over time.