Abnormalities may originate in a peripheral nerve because they are abolished by curare but usually persist after general anesthesia. Carbamazepine or phenytoin relieves symptoms. A disease characterized by episodic muscle weakness caused by loss or dysfunction of acetylcholine receptors. An autoimmune attack destroys or impairs the function of acetylcholine receptors at the postsynaptic neuromuscular junction, interfering with neuromuscular transmission. The initiating event leading to antibody production is unknown.
Symptoms resolve in days to weeks as antibody titers decline.
Congenital myasthenia is a rare autosomal recessive disorder of neuromuscular transmission beginning in childhood. Acetylcholine-receptor antibodies are absent, so the disease is not autoimmune. Ophthalmoplegia is common. The most common symptoms are ptosis, diplopia, and muscle fatigability after exercise. Dysarthria, dysphagia, and proximal limb weakness are common.