Myasthenia gravis

Diagnosis

A physical examination and review of the patient’s symptoms will be performed by the healthcare provider. They could conduct a variety of tests, such as:

• Neurological examination: An examination of reflexes, muscle strength, muscle tone, senses of touch and sight, coordination, and balance are some of the neurological processes that a healthcare provider may use to determine neurological health.
• Imaging test: To screen for a tumor or other abnormality in the thymus, a healthcare provider may request a computed tomography (CT) scan or a magnetic resonance imaging (MRI).
• Electromyography (EMG): This test evaluates the electrical signals passing between your brain and muscles. It requires the insertion of a thin wire electrode through your skin into a muscle to examine the activity of a single muscle fiber.
• Ice pack test: In cases of a droopy eyelid, a common approach used by doctors is the application of an ice-filled bag on the affected eyelid. After a duration of approximately two minutes, the bag is removed, and the doctor carefully evaluates the eyelid for any noticeable signs of improvement.
• Blood analysis: A majority of individuals with MG exhibit elevated levels of acetylcholine receptor antibodies in their bloodstream, accounting for around 85% of cases. About 6% of patients with MG possess muscle-specific kinase (MuSK) antibodies. It should be noted that antibodies may not be detectable in less than 10% of individuals diagnosed with MG.
• Repetitive nerve stimulation: During a nerve conduction study for diagnosing myasthenia gravis, medical professionals apply electrodes to the skin above the targeted muscles. By administering small electrical pulses through these electrodes, they assess the nerve’s capacity to transmit signals to the muscles. Through repetitive testing, doctors observe if the nerve’s signal transmission deteriorates with fatigue, which aids in the diagnosis of myasthenia gravis.
• Pulmonary function tests: These tests assess if your breathing is being impacted by your condition.

Treatment

Treatment options for myasthenia gravis include a range of approaches that can be used individually or in combination. The choice of treatment depends on factors such as your age, the severity of your condition, and the rate of its progression.

• Medications
  • Cholinesterase inhibitors: Pyridostigmine (Mestinon, Regonal) is a medication that enhances the communication between nerves and muscles, leading to improved muscle contraction and strength for certain individuals. While it is not a curative treatment, it can be beneficial. However, potential side effects may include gastrointestinal discomfort, diarrhea, nausea, as well as increased salivation and sweating.
  • Corticosteroids: Prednisone is a type of corticosteroid that works by suppressing the immune system, thereby reducing antibody production. Although it can be effective, prolonged usage of corticosteroids carries the risk of significant side effects. These include bone thinning, weight gain, the potential development of diabetes, and an increased susceptibility to certain infections.
  • Immunosuppressants: In addition to corticosteroids, doctors may prescribe medications such as azathioprine, mycophenolate mofetil, cyclosporine, methotrexate, or tacrolimus to modify the immune system. These immunosuppressants, although they may require several months to take effect, can have significant side effects including a heightened susceptibility to infections as well as potential damage to the liver or kidneys.
• Intravenous therapy: The following treatments are typically used in the short term to alleviate a rapid worsening of symptoms prior to surgery or other treatments.
  • Plasmapheresis: This procedure employs a dialysis-like filtering process where your blood is directed through a machine to eliminate antibodies that hinder the transmission of signals between your nerve endings and muscle receptors. Nonetheless, the positive outcomes are typically temporary, lasting only a few weeks, and undergoing multiple treatments can pose challenges in accessing veins for the procedure. Plasmapheresis carries risks such as a decrease in blood pressure, bleeding, irregular heart rhythms, or muscle cramps. Additionally, certain individuals may experience allergic reactions to the solutions used as plasma replacements.
  • Intravenous immunoglobulin (IVIg): The immune system’s reaction is changed by this therapy’s supplying the body with healthy antibodies. Benefits might last between three and six weeks and are usually seen in less than a week.
  • Monoclonal antibody: Rituximab and eculizumab are intravenous medications utilized in the treatment of myasthenia gravis. Typically reserved for individuals who have not responded to alternative therapies, these drugs may produce significant side effects.
• Surgery:
  • Myasthenia gravis patients may have a thymoma tumor in their thymus gland, which can be surgically removed through a procedure called thymectomy. However, even without a tumor, thymectomy can still potentially improve symptoms of myasthenia gravis, although it may take several years to see the benefits. Thymectomy can be performed either as an open surgery, where the sternum is split to access and remove the thymus gland, or as a minimally invasive procedure.

Minimally invasive surgery, aimed at removing the thymus gland, utilizes smaller incisions and may incorporate the following techniques:

• • Video-assisted thymectomy: During a specific type of surgical procedure, a small cut is made either in the neck or a few minor incisions are created on the side of the chest. Subsequently, surgeons employ a slender camera known as a video endoscope, along with tiny instruments, to visualize and extract the thymus gland.
  • Robot-assisted thymectomy: During this type of thymectomy, surgeons utilize a robotic system comprising a camera arm and mechanical arms. The procedure involves creating multiple small incisions on the side of the chest and using the robotic system to extract the thymus gland.