An Animal Model as New Tactics to Study the Effects of a Varying Body Temperature on Evoked Potentials

There has long been a meed for a refined way of studying the effects of a varying body temperature on evoked potentials. The descending conductive spinal cord evoked potential (SCEP), taken by spinal epidural records after a spinal epidural stimulation, was studied by use of a canine model to confirm its usefulness in obtaining more detailed information about changes of evoked potentials while the body temperature is being varied. In this model, the change in body temperature was brought by heating or cooling the blood through an extracorporeal circuit. The relationship between the spinal cord temperature and the latencies and the amplitudes of the SCEP was then considered. The precise changes in the SCEP during a varying body temperature were as follows : the latencies of the SCEP components were shortened and the amplitude was consecutively reduced, with an elevation of the spinal cord temperature. On the other hand, the latencies were prolonged and the amplitude was increased with a decrease in the temperature. This model holds promise for determing the precise effect of temperatures on various evoked potentials and also for predicting the conduction velocities of neurons in the central nervous system.