12. Diseases of the muscle and neuromuscular junction

Diseases of the muscles and the neuromuscular junction have a common symptom, namely loss of strength. Atrophy and cramps are also found. Many muscular diseases have a genetic cause and are almost untreatable, but this is why it is very important to recognize acquired diseases, as a good deal can usually be done about them therapeutically. When classifying muscular diseases a distinction needs to be made between proximal and distal myopathies, and between diseases with and without myotonia. Myasthenia is a special case: unlike most other muscular diseases it often causes diplopia, and the severity of the symptoms fluctuates. Myasthenias are usually autoimmune diseases and as such respond well to treatment, but incorrect treatment can cause life-threatening situations. In cases of muscular disease care needs to be taken with anaesthesia and good genetic advice must be given.