[Technical details for recording trigeminal evoked potentials in the cat].

Experiments were undertaken to establish technical standards for recording of trigeminal evoked potentials (TEP) as a tool for assessment of the effectiveness of various therapeutic procedures for trigeminal neuralgia. Serial changes in the action potentials of the maxillary nerve and TEP were studied when parameters of electrical stimulation, namely, intensity and frequency, and position of electrodes were altered. The effects of use of muscle relaxants and change of body temperature of animals on TEP were also studied. On the basis of these experimental results, the technical details most suitable for TEP recording in cat were explored. The most distinct TEP was recorded under the following animal conditions and parameters: keeping rectal temperature between 37.5 degrees C and 38.5 degrees C, slackening with muscle relaxants, stimulating the infraorbital nerve with 10 volts of square-pulse electricity 5 times per second in short latency TEP and 2 times per second in long latency TEP, placing the active electrode on the vertex for short latency TEP and on the primary sensory area for long latency TEP. Eight positive peaks and three negative peaks were recorded under these conditions. The average and standard deviations of peak latency of potential from 10 cats were as follows: P 1, 0.67 +/- 0.04 msec; N 1, 0.89 +/- 0.07 msec; P 2, 1.35 +/- 0.10 msec; P 3, 1.89 +/- 0.08 msec; P 4, 2.43 +/- 0.26 msec; P 5, 3.17 +/- 0.15 msec; P 6, 3.36 +/- 0.21 msec; P 7, 5.02 +/- 0.39 msec; P 8, 6.07 +/- 0.35 msec; N 2, 10.4 +/- 1.15 msec; N 3, 18.5 +/- 1.74 msec.(ABSTRACT TRUNCATED AT 250 WORDS)