Myasthenia gravis is characterized by weakness and rapid fatigue of any of the muscles under your voluntary control. It’s caused by a breakdown in the normal communication between nerves and muscles.
Though this disease can affect people of any age, it’s more common in women younger than 40 and in men older than 60.MG affects about 20 out of every 100,000 people
What causes myasthenia gravis?
Myasthenia gravis is not inherited and it is not contagious. It generally develops later in life when antibodies in the body attack normal receptors on muscle. This blocks a chemical needed to stimulate muscle contraction.
A temporary form of myasthenia gravis may develop in the fetus when a woman with myasthenia gravis passes the antibodies to the fetus. Generally, it resolves in 2 to 3 months.
These factors increase risk:
- History of other autoimmune diseases, such as rheumatoid arthritis and lupus.
- Medications for malaria, heart arrhythmias and cancer.
- Surgical procedures.
What are the symptoms of myasthenia gravis?
Visual problems, including drooping eyelids (ptosis) and double vision (diplopia)/Muscle weakness and fatigue may vary rapidly in intensity over days or even hours and worsen as muscles are used (early fatigue)/Facial muscle involvement causing a mask-like appearance. Trouble swallowing or pronouncing words
Your doctor may check your neurological health by testing:
- Reflexes
- Muscle strength
- Muscle tone
- Senses of touch and sight
- Coordination
- Balance
Two-thirds of young people with MG have overactive thymic cells (thymic hyperplasia). About one in 10 people with MG have thymus gland tumors called thymomas, which may be benign (not cancer) or cancerous.
How is myasthenia gravis diagnosed?
Your healthcare provider will perform a physical exam and assess your symptoms. You may undergo these tests:
- Antibody tests: About 85% of people with MG have unusually high levels of acetylcholine receptor antibodies in their blood. Approximately 6% patients have muscle-specific kinase (MuSK) antibodies.
- Imaging scans: An MRI or CT scan can check for thymus gland problems like tumors.
- Electromyogram (EMG): An EMG measures the electrical activity of muscles and nerves. This test detects communication problems between nerves and muscles.
What are the complications of myasthenia gravis?
Weakness and fatigue from MG can keep you from participating in activities you enjoy. This may lead to depression.
Up to one in five people with MG experience a myasthenic crisis or severe respiratory muscle weakness
Treatments for MG focus on improving symptoms. Treatments include:
- Medications: Cholinesterase inhibitors (anticholinesterase) boost signals between nerves and muscles to improve muscle strength. Immunosuppressants, including corticosteroids.
- Monoclonal antibodies: You receive intravenous (IV) infusions of biologically engineered proteins. These proteins suppress an overactive immune system.
- IV immunoglobulin (IVIG): You receive IV infusions of donor antibodies over a period of two to five days. IVIG can treat myasthenia crisis as well as generalized MG.
- Plasma exchange (plasmapheresis): An IV line removes abnormal antibodies from your blood.
- Surgery: A thymectomy is surgery to remove the thymus gland. Even if tests don’t show a problem with your thymus gland, surgical removal sometimes improves symptoms.
Dr Gautam Arora MD DM ( Neurology and Pain Management )
NPMC
Block A 90 Kamla Nagar
Delhi North
Ph 8595168656
www.neuroandpain.clinic