Investigating Ocular Movements and Vestibular Evoked Potentials for a Vestibular Neuroprosthesis: Response to Pulse Trains and Baseline Stimulation

No adequate treatment currently exists for bilateral vestibulopathy, which can result in significant decreases of social and physical functioning. To improve patients' quality of life, vestibular neuroprostheses are being developed. Efficacy of current prototypes is evaluated by recording reflexive eye movements (vestibular ocular reflex, VOR). Vestibular Evoked Potentials (VEPs) provide real-time feedback about peripheral efficacy that could be used to adapt a closed-loop neuroprosthesis to improve performance (e.g., eye movement magnitude and direction). A key building block is the prediction of VOR with VEP. In earlier work, we correlated both in response to single stimulation pulses. While impulse responses are interesting, they do not reflect a typical operating mode. To learn more about VEP at expected modulations, we studied the impact of pulse trains and baseline stimulation on VEP here. At 250 pulses per second, VEP did neither change significantly for pulse trains nor over the course of 30-minute baseline stimulation. VOR, on the other hand, changed with the number of pulses, and was also influenced by baseline stimulation.