Replacing semicircular canal function with a vestibular implant

Abstract

Purpose of review: To summarize the recent progress in the development of vestibular implants. The review is timely because of the recent advances in the field and because MED-EL has recently announced that they are developing a vestibular implant for clinical applications.

Recent findings: The handicap experienced by patients suffering from bilateral vestibulopathy has a strong negative impact on physical and social functioning that appears to justify a surgical intervention. Two different surgical approaches to insert electrodes to stimulate ampullary neurons have been shown to be viable. The three-dimensional vestibulo-ocular reflex in rhesus monkeys produced with a three-dimensional vestibular implant showed gains that were relatively normal during acute stimulation. Rotation cues provided by an implant interact with otolith cues in a qualitatively normal manner. The brain appears to adapt plastically to the cues provided via artificial electrical stimulation.

Summary: Research to date includes just a few human studies, but available data from both humans and animals support the technological and physiological feasibility of vestibular implants. Although vestibular implant users should not expect normal vestibular function - any more than cochlear implant users should expect normal hearing - data suggest that significant functional improvements are possible.