Detection of largyneal sensory-evoked potentials (LSEPs) in the cat

We previously reported on evoked potentials elicited by electrical stimulation of the superior laryngeal nerve at an appropriate site on the dural surface as a reflection of activities in the brain stem and cortex in anesthetized cats. This evoked potential was called the laryngeal sensory evoked potential (LSEP). In this study we attempted to establish a less invasive procedure for measuring LSEP. The procedures were recording on the scalp using chloride-coated silver disk electrodes and stimulation by insertion of a bipolar platinum hooked wire electrode into the laryngeal mucosa. Evoked potentials could be detected using these less invasive procedures. The response morphologies and relative timing of LSEP components were quite similar for each method in a given cat. However, the amplitudes were slightly lower and the latencies were slightly prolonged with the less invasive techniques. These results suggest that this LSEP method might be applicable to human beings as a noninvasive method for evaluating the function of the laryngeal sensory pathway.