Trigeminal evoked potentials in humans.

Techniques were described for recording trigeminal evoked potentials in humans in response to maxillary gum stimulation. Variations in the responses as a function of stimulating and recording electrode position and stimulus intensity were presented. A standard methodology was proposed in order to obtain the characteristic response repeatedly. The characteristic triphasic wave form consisted, primarily, of an N20, P34, N51 sequence of deflections. Average latencies of components were derived from recordings following stimulation of the asymptomatic side of the face in a patient population. Indirect tests supported the view that muscle potentials did not significantly contribute to the characteristic response. It was concluded that the techniques were suitable for electrophysiological testing of fifth nerve function in routine clinical applications.