[The repetitive muscular action potential in neuromuscular transmission disorders due to acetylcholinesterase inhibition].

Neuromuscular transmission was studied in 11 patients with organophosphate intoxication. The compound muscle action potential (MAP) was recorded from the thumb after single, repetitive (1-50 Hz) and paired stimulation. All patients showed a prolonged MAP. The duration increased with the severity of intoxication. The number of peaks varied only slightly. In all cases repetitive stimulation reduced the later components of the MAP. There was no correlation with tetanic fade of the initial negative component. One patient had a pronounced tetanic fade but a slight reduction of repetitive components. In view of experimental studies a combined pre- and postsynaptic effect seems to be responsible.