Myasthenia gravis

Synonyms

  • Myasthenia gravis pseudoparalytica
  • Hoppe Goldflam Syndrome
  • Hereditary Gold Flame Disease

Summary

Myasthenia gravis is a disease of the nerve-muscle junction (neuromuscular endplate; see Muscular Anatomy) from the group of autoaggressive diseases. The immune system of the affected person produces (auto)antibodies against the receptors (recipients) for the messenger substance that triggers the translation of a nerve impulse into a mechanical action (muscle contraction). This leads to a progressive destruction of these receptors with the consequence that a nerve impulse is followed by an increasingly weak muscle action (muscle weakness).

If left untreated, myasthenia gravis progresses continuously to varying degrees and may be fatal by infecting the respiratory muscles. The progression of the disease can be slowed or even stopped by medication to influence the affected person’s immune system. On the other hand, there are many common medications (e.g. anesthetics) that can worsen the symptoms of myasthenia gravis, so it is advisable for those affected to obtain a “myasthenia passport” to inform first responders and therapists of this fact.

Definition

Myasthenia gravis is an autoimmune disease that leads to progressive damage at the interface between nerves and muscle. The destruction of receptors for the messenger substance at the junction causes pathologically increased fatigue and weakness of the affected muscles.

Frequency

Myasthenia gravis occurs with a frequency of 4 – 10/100000, the disease occurs more frequently either at the age of 20 – 40 years or at the age of 60 – 70 years, very rarely also once in childhood. Women are more frequently affected than men.

Causes

Myasthenia gravis is caused by an autoaggressive process of the immune system, in which the immune system produces antibodies against receptors of the neuromuscular endplate. In many cases a change in the thymus (immunological organ in childhood, which usually regresses in adulthood) is detected. As with many autoimmune diseases, there is a certain hereditary component. In rare cases, symptoms of myasthenia gravis can also occur in connection with other diseases, e.g. hyperthyroidism, rheumatoid arthritis or other autoimmunological diseases. Mental and physical stress as well as secondary diseases can intensify the symptoms of myasthenia gravis.