Affiliations: [a] Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA | [b] Department of Otology and Neurology, Harvard Medical School, Boston, MA, USA | [c] Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, USA | [d] Health Sciences and Technology, Harvard University and Massachusetts Institute of Technology, Cambridge, MA, USA
Correspondence:
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Corresponding author: Lara A. Thompson, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA 02114, USA. Tel.: +1 617 573 6491; Fax: +1 617 573 4154; E-mail: [email protected]
Note: [1] This paper is based upon a presentation at a symposium entitled, “Prosthetic Stimulation of the Vestibular System” on February
20, 2011 at the 34th Annual Midwinter Research Meeting of the Association for Research in Otolaryngology.
Abstract: Patients with bilateral vestibular loss experience dehabilitating visual, perceptual, and postural difficulties, and an implantable vestibular prosthesis that could improve these symptoms would be of great benefit to these patients. In previous work, we have shown that a one-dimensional, unilateral canal prosthesis can improve the vestibulooccular reflex (VOR) in canal-plugged squirrel monkeys. In addition to the VOR, the potential effects of a vestibular prosthesis on more complex, highly integrative behaviors, such as the perception of head orientation and posture have remained unclear. We tested a one-dimensional, unilateral prosthesis in a rhesus monkey with bilateral vestibular loss and found that chronic electrical stimulation partially restored the compensatory VOR and also that percepts of head orientation relative to gravity were improved. However, the one-dimensional prosthetic stimulation had no clear effect on postural stability during quiet stance, but sway evoked by head-turns was modestly reduced. These results suggest that not only can the implementation of a vestibular prosthesis provide partial restitution of VOR but may also improve perception and posture in the presence of bilateral vestibular hypofunction (BVH). In this review, we provide an overview of our previous and current work directed towards the eventual clinical implementation of an implantable vestibular prosthesis.
