Neuromuscular transmission has been studied electromyographically in thirty diabeticpatients. The median nerve was stimulated rapramaximally at the wrist, and the evoked electrical response of the abductor pollicis brevis was recorded on a cathode ray oscilloscope. Pulse trainsof twenty to twenty-four stimuli were used in frequency varying from 2 to 500 per second.
In all patients the twitch rate of nerve stimulation was well maintained. Tetanic stimulation, however, was poorly sustained. A progressive decrement of the action potential amplitude occurred rapidly and earlier in many patients at frequencies that facilitated or left unchanged the amplitude in normal subjects. The drop in amplitude was particularly evident with trains of 50 and 100 per second.
He easy fatigability of neuromuscular transmission was present in clinically not involved nerve and muscle and could represent an early and only evidence of neuronal failure in diabetic patients.