Myasthenia gravis is a chronic autoimmune, neuromuscular disease characterized by muscle weakness and extreme fatigue. The name comes from Latin and Greek which implies grave muscular weakness. Certain muscles that control the movement of the eyes, face, and swallowing are often involved in the disorder. This ailment happens due to cell-mediated destruction of acetylcholine receptors. When myasthenia gravis affects the body, antibodies block or destroy the receptors for acetylcholine at the neuromuscular junction, thus preventing the muscle from functioning properly. While it is more common among young women, it may occur in adults of any age group. The onset of symptoms could be sporadic or intermittent and the degree of weakness and fatigue involved in myasthenia gravis may vary among individuals. Timely diagnosis and the right treatment (which mostly involves therapies) can help patients live a high quality of life.
Myasthenia

Causes Of Myasthenia Gravis

Antibodies:

When the nerve impulse originating in the brain arrives at the nerve ending, it releases a chemical called acetylcholine. Acetylcholine travels to the muscle fiber side of the neuromuscular junction (a space between the nerve ending and muscle fiber) where it attaches to many receptor sites. The muscle contraction happens when enough of the receptor sites have been activated by the acetylcholine. In this autoimmune disorder, antibodies attack their own parts, destroying the receptors for acetylcholine thus impairing transmission at the neuromuscular junction. When normal communication between the nerve and muscle is interrupted at the point where nerve cells connect with the muscles they control, the ailment starts to develop.

Also Read: Autoimmune Disease: Learn What It Is About

The Thymus Gland:

Thymus plays an important role in the overall functioning development of the immune system. Responsible for producing T-lymphocytes or T-cells these white blood cells protect the body from infections. Any malfunctioning of this gland is associated with this disorder. In many cases of myasthenia gravis, due to the enlargement of the thymus gland, individuals typically have clusters of immune cells in their thymus gland, and they develop tumors in this gland. The thymus gland gives incorrect instructions to developing immune cells, ultimately causing the immune system to attack its own cells and tissues.

Symptoms Of Myasthenia Gravis

Not as grave as the name implies, most cases of myasthenia gravis can be managed with therapy. People with myasthenia gravis may experience the following symptoms:

  • Weakness in the arms, hands, fingers, legs and neck
  • Muscle weakness after use of the affected muscle
  • Weakness of the eye muscles called ocular myasthenia, and eyelid drooping
  • Shortness of breath
  • Blurred or double vision
  • Change in facial expressions
  • Difficulty swallowing
  • Impaired speech

Diagnosis

Diagnosis of myasthenia gravis is done by anti-acetylcholine receptor (ACHR) antibody test to look for a type of antibody that stops signals from being sent between the nerves and muscles. Higher levels of these antibodies imply you have myasthenia gravis.

Treatment

Just like most autoimmune disorders, most likely myasthenia gravis can merely be controlled and there is no specific treatment. There are special therapies available to help reduce and improve muscle weakness but those should be taken only in severe cases of myasthenia gravis. While these treatments remove the destructive antibodies, their effectiveness generally lasts for a few weeks to months. The most common therapies are:

Thymectomy:

This surgery is done to surgically remove the abnormal functioning thymus gland. In some cases, it reduces symptoms and cures some people by rebalancing the immune system.

Anticholinesterase Drugs:  

Medications to treat the disorder include anticholinesterase are given which slows the breakdown of acetylcholine at the neuromuscular junction. It helps improve neuromuscular transmission and increase muscle strength. 

Immunosuppressive Drugs:

These drugs improve muscle strength by suppressing the production of abnormal antibodies. However, the drugs can cause significant side effects.

 Plasmapheresis And Intravenous Immunoglobulin:

 Plasmapheresis is a procedure to remove harmful antibodies in plasma and replace them with good plasma or a plasma substitute.