Human Vestibulo-Spinal Responses to Direct Electrical Eighth Nerve Stimulation

Abstract

Left-right (y-axis) vestibulo-spinal torque responses were recorded from two of four intramodiolar stimulus electrodes placed for auditory stimulation in one human subject. For both electrodes, shorter (100 msec) stimuli caused either subjective or objective head turning whereas stimuli lasting longer than 0.5 sec caused either subjective or objective body tilt depending upon the electrode stimulated. The two electrodes tested also showed strikingly different auditory and vestibular effects. Stimulation of the remaining two electrodes caused no detectable vestibulo-spinal responses.