Neuromuscular transmission defect in inherited polyneuropathy.

A 51-year-old woman with an inherited polyneuropathy had fatiguability and a dramatic historical response to prostigmine. Repetitive motor nerve stimulation produced a prominent decrement of the compound muscle action potential in distal muscles with marked facilitation after brief exercise. Defective neuromuscular transmission paralleled the polyneuropathy in distribution and severity. We hypothesize that deficient release of acetylcholine by regenerating or degenerating nerve terminals likely caused the defect of neuromuscular transmission in this patient.