The Effects of Temperature on Conduction in Demyelinated Single Nerve Fibers

Abstract

Increases of temperature of 0.5 C within the physiological range of temperature cause reversible conduction block at identifiable internodes of experimentally demyelinated rat ventral root fibers; such internodes invariably have greatly increased internodal conduction times. At less severely affected internodes, increased temperature causes a reduction in internodal conduction time, as at normal internodes. Such reversible conduction block with increased temperature in demyelinated fibers is suggested as the explanation for the temperature sensitivity of signs and symptoms of patients with multiple sclerosis. It is also suggested that the chronic slowing of conduction that is known to occur in demyelinated nerve fibers is probably of minor clinical significance in human demyelinating disease.