The literal meaning of the words “myasthenia gravis” is grave muscle weakness. Myasthenia gravis is a rare autoimmune disorder that occurs due to production of antibodies against acetylcholine receptors (AChR). The antibodies attach to these receptors and hence don’t allow binding of acetylcholine at the receptor site thereby leading to decreased action of acetylcholine. Due to this there is blockage of nerve signal transmission and hence muscle weakness results. The incidence rate of this disease is 0.25 to 20 amongst 1,000,000 populations, annually. This is a chronic disease. It can be diagnosed with the help of tests like edorphonium test, electromyography and testing the presence of acetylcholine receptor antibodies in the blood. (2)

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Can You Be Cured Of Myasthenia Gravis?

No, you cannot be cured of myasthenia gravis. It is a life long disease. There are various treatment options available that help in controlling the signs and symptoms of the disease but it is a non-curable disease. (1)

Following are the treatment options available for myasthenia gravis-

Treatment With Pyridostigmine- Pyridostigmine is an anticholinesterase, this drug inhibits the action of acteylcholinesterase which is an enzyme that causes break down of acetylcholine. By blocking the action of acteylcholinesterase, the action of acetylcholine is prolonged. Along with prolonging action of acetylcholine, this drug also diminishes the attack by antibodies at motor end plates. Pyridostigmine has side effects like diarrhea, intestinal colic and these can be controlled with the help of a drug named propantheline.

Sometimes when this drug is given in excess, it may lead to cholinergic crisis. It occurs because of receptor block at the motor end plates. The symptoms of cholinergic crisis are pallor, sweating, paralysis, muscle fasciculations, pinpoint pupils and excessive salivation.

Intravenous Immunoglobulin (IVIg)- By giving intravenous immunoglobulin, the production of antibodies decreases and also a rapid improvement in the condition of the patient is seen as the weakness fades away quickly.

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Plasmapheresis- In this procedure, the blood is made to flow through a machine that separates the plasma containing antibodies in the blood of patient and in turn, replaces it with plasma that is free of antibodies. This is done only in severe cases.

Treatment With Corticosteroids- Corticosteroids are the drugs that help by reducing the production of antibodies in the blood but these drugs have major side effects. Once started, corticosteroids are continued for months or may be for years.

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Immunotherapeutic Agents- Immunotherapeutic agents are added to the treatment to reduce the dosage of corticosteroids and are also helpful when corticosteroids are needed to be withdrawn. The most commonly used drug is azathioprine. Rarely mycophenolate is also used.

Thymectomy- Thymectomy is a surgical procedure where the thymus gland is surgically removed from the body. Thymus is a gland that takes part in production of antibodies. But this treatment option does not result in cure of disease but it surely helps in decreasing the symptoms and signs of the disease. Recurrence of the symptoms is also seen sometimes. (3)

Complications Of Myasthenia Gravis

Myasthenic crisis is the most serious complication of myasthenia gravis. It is a life threatening condition. In this condition the weakness of muscles especially the diaphragm and muscles of chest that aid in breathing, worsens to an extent that the patient might require ventilation or intubation because the muscles of throat weaken and this leads to collection of respiratory secretions and hence blockage.

The trigger factors that may cause myasthenic crisis are-

  • Emotional stress
  • Pregnancy
  • Pain
  • High temperature
  • Low temperature
  • Infections
  • Surgical interventions
  • Sleep deprivation
  • Aspiration pneumonitis

Symptoms of myashtenic crisis-

  • Difficulty in breathing (breathlessness)
  • Difficulty in speaking (dysarthria)
  • Headache in the morning time
  • More fatigue in daytime
  • Increased frequency of awakening at night
  • Feeling restlessness throughout the day
  • Increased mucus and saliva production
  • Coughing
  • Difficulty in swallowing (dysphagia)
  • Difficulty in chewing food
  • Weakness of tongue
  • Chest in-drawing while breathing

Treatment Of Myasthenic Crisis

Mechanical Ventilation And Intubation- Almost as much as 90% of patients who undergo myasthenic crisis require mechanical ventilation and intubation.
Suctioning- There is increased mucus production so regular suction of these mucus secretions must be done for proper ventilation.

Anticholinesterases- Anticholinesterases must be administered in order to increase the amount of acetylcholine at the muscle end plates. This will improve muscle strength.

Immunosuppressants- These will help in reducing the immune response and help in improving the symptoms of myasthenic crisis.

Intravenous Immunoglobulins (IVIg)- Injecting immunoglobulins will help in reducing the severity of disease.

Plasma Exchange Or Plasmapheresis- The plasma from the blood is separated and healthy plasma with no abnormal antibodies is infused into the body of patient and this helps by reducing the immune response. (3)

Conclusion

Myasthenia gravis is an autoimmune disease that harms the neuromuscular junctions of the body. There are acetylcholine receptors present at the neuromuscular junctions that help in transmission of the nerve impulses. In this disease antibodies are produced against these receptors and hence the nerve transmission is hampered. This disease can be managed with the help of medications but no cure is yet available for this disease.

References-

  1. https://www.ncbi.nlm.nih.gov/pubmed/29932785
  2. https://www.mayoclinic.org/diseases-conditions/myasthenia-gravis/diagnosis-treatment/drc-20352040
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3726100/

Also Read:

Pramod Kerkar

Written, Edited or Reviewed By:

, MD,FFARCSI

Pain Assist Inc.

Last Modified On: May 8, 2019

This article does not provide medical advice. See disclaimer

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