title: Replacing semicircular canal function with a vestibular implant.
abstract: OBJECTIVE
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA. dan_merfeld@meei.harvard.edu
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Merfeld
authors.forename: Richard F
authors.initials: RF
authors.lastname: Lewis
mesh_terms: D000818:Animals; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D058542:Implantable Neurostimulators; D008253:Macaca mulatta; D008297:Male; D019919:Prosthesis Implantation / Q000379:methods*; D018570:Risk Assessment; D012665:Semicircular Canals / Q000503:physiopathology / Q000601:surgery*; D012720:Severity of Illness Index; D016896:Treatment Outcome; D015837:Vestibular Diseases / Q000175:diagnosis / Q000601:surgery*