Myasthenia Gravis Explained: Causes, Symptoms, and Treatment Options

What is Myasthenia Gravis:

Have you ever wondered what is myasthenia gravis. It is a neuromuscular condition that affects the nerves and muscles that help the body move, also called skeletal muscles. It develops primarily due to an autoimmune disorder. The disease is long-term and cannot be cured entirely. The present blog explains myasthenia gravis, its causes, how to identify it, and the various treatment options available.  

Myasthenia gravis causes:

Myasthenia gravis causes can be linked to the following:  

• The body's inability to recognize its cells leads to myasthenia gravis. This unrecognition leads to the immune system's self-destruction of the body's cells. For a muscle to function, nerves send signals that pass through a junction between the nerves and the muscles.  
• The thymus gland's production of autoantibodies also causes myasthenia gravis. These antibodies destroy the receptor sites necessary for a neurotransmitter molecule called acetylcholine. This molecule acts as a messenger between the nerves and muscles by transferring signals. Due to reduced receptor sites, the molecule is less bound, leading to a lack of signal to the muscle, resulting in muscle weakness.  
• Muscle-specific receptor tyrosine kinase, which is needed for the muscle to accept signals, is blocked, leading to Myasthenia gravis. These proteins are necessary for the functioning of the nerve-muscle junction. This blockage results in decreased signals to the skeletal muscles, leading to weakness or reduced functioning of the skeletal muscles.  
• Apart from these, various other proteins also lead to the development of myasthenia gravis.

Myasthenia Gravis types:

Based on the type of damage, myasthenia gravis is of various kinds. They are:

• Autoimmune myasthenia gravis is the most common type due to self-destruction by antibodies produced in the body. This autoimmune type has two subtypes called: ocular and generalized myasthenia gravis.
• Neonatal myasthenia gravis is caused by transmitting antibodies from the mother to her child. It is a temporary condition that subsides in three months.  
• Congenital myasthenia gravis is caused by a genetic defect. It can be inherited when two recessive genes are inherited from each parent.

Myasthenia gravis symptoms:

Myasthenia gravis symptoms mainly include muscle weakness. Worsening of the symptoms in the initial days of diagnosis and progression are prominent features of the disease. Myasthenia gravis symptoms subside when resting, but muscle weakness tends to come and go.  

• Fatigue
• Drooping of eyelids called ptosis  
• Vision disturbances leading to blurry or double vision  
• Difficulty in making facial expressions, speaking, swallowing, chewing, or walking
• Breathlessness if the respiratory muscles are affected  
• Difficulty in getting from a sitting position
• Inability to lift the hands
• Inability to walk long distances and climb stairs  
• Myasthenia gravis symptoms worsen when exerting the muscles and reduce upon rest.  
• Ocular myasthenia is a condition where different eye problems are seen in myasthenia gravis. Sometimes, it is the first symptom to develop, which can later develop into a generalized one. Generalized myasthenia affects muscles of the face, neck, arms, legs, and throat, leading to various symptoms.  

What increases the risk of Myasthenia gravis:

Females around 40 years of age, males around 60 years of age, history of other autoimmune diseases and thyroid disorders increase the risk of myasthenia.  

Some may have myasthenia gravis but may not develop symptoms. However, infections, surgeries, and anti-malarial or arrhythmia medications can trigger the condition.  

Myasthenia gravis diagnostic tests:

Myasthenia gravis treatment depends on its diagnosis. To diagnose myasthenia gravis, the healthcare provider does a physical examination and may prescribe specific tests. Based on the physical examination, myasthenia gravis is classified as follows:

• Class I, if the myasthenia is restricted to the eyes
• Class II if the myasthenia causes mild muscle weakness  
• Class III if the myasthenia causes moderate muscle weakness  
• Class IV if the myasthenia causes severe muscle weakness  
• Class V if the myasthenia affects the respiratory system  

After the physical examination, specific myasthenia gravis diagnostic tests include:

• Antibody tests to detect acetylcholine receptor levels and muscle-specific kinase levels in the blood.  
• Imaging tests like a computed tomography scan and magnetic imaging resonance scan to detect tumors in thymus glands  
• Electromyography tests measure the electrical activity and communication between the muscles and nerves to diagnose myasthenia.  

Treatment:

• Myasthenia gravis treatment targets its symptoms. Oral and intravenous medications and surgery are the mainstay of myasthenia management.  
• Medications for myasthenia gravis treatment include those that improve the communication between nerves and muscles, reduce the production of antibodies, and modulate the immune system. These help to improve muscle strength and contractions. Filtration procedures such as plasmapheresis, intravenous immunoglobulins, and monoclonal antibodies treat worsened myasthenia gravis symptoms.  
• Surgery for myasthenia gravis treatment treats thymus tumors to reduce the production of antibodies from the thymus; however, the results have appeared lately.  
• Dietary and lifestyle modifications, electrical appliance usage, and following safety rules help control myasthenia gravis symptoms.  

Conclusion

Myasthenia gravis is a neuromuscular condition that can significantly affect quality of life. Early recognition of its causes, diagnosis, and treatment helps control the disease. Fortis Hospital has experienced neurologists who can diagnose the condition using state-of-the-art methods. They also have a multidisciplinary team of experts who can manage myasthenia gravis and improve outcomes.