Chronic Vestibulo-Ocular Reflexes Evoked by a Vestibular Prosthesis

We are developing prosthetics for patients suffering from peripheral vestibular dysfunction. We tested a sensory-replacement prosthesis that stimulates neurons innervating the vestibular system by providing chronic pulsatile stimulation to electrodes placed in monkeys´ lateral semicircular canals, which were plugged bilaterally, and used head angular velocity to modulate the current pulse rate. As an encouraging finding, we observed vestibulo-ocular reflexes that continued to be evoked by the motion-modulated stimulation months after the nystagmus evoked by the constant-rate baseline stimulation had dissipated. This suggests that long-term functional replacement of absent vestibular function is feasible