title: Longitudinal performance of an implantable vestibular prosthesis.
abstract: Loss of vestibular function may be treatable with an implantable vestibular prosthesis that stimulates semicircular canal afferents with biphasic pulse trains. Several studies have demonstrated short-term activation of the vestibulo-ocular reflex (VOR) with electrical stimulation. Fewer long-term studies have been restricted to small numbers of animals and stimulation designed to produce adaptive changes in the electrically elicited response. This study is the first large consecutive series of implanted rhesus macaque to be studied longitudinally using brief stimuli designed to limit adaptive changes in response, so that the efficacy of electrical activation can be studied over time, across surgeries, canals and animals. The implantation of a vestibular prosthesis in animals with intact vestibular end organs produces variable responses to electrical stimulation across canals and animals, which change in threshold for electrical activation of eye movements and in elicited slow phase velocities over time. These thresholds are consistently lower, and the slow phase velocities higher, than those obtained in human subjects. The changes do not appear to be correlated with changes in electrode impedance. The variability in response suggests that empirically derived transfer functions may be required to optimize the response of individual canals to a vestibular prosthesis, and that this function may need to be remapped over time. This article is part of a Special Issue entitled <Lasker Award>.
authors.affiliation: Otolaryngology - HNS, University of Washington, Seattle, WA, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Phillips
authors.affiliation: Otolaryngology - HNS, University of Washington, Seattle, WA, USA; Washington National Primate Research Center, University of Washington, Seattle, WA, USA.
authors.forename: Leo
authors.initials: L
authors.lastname: Ling
authors.affiliation: Washington National Primate Research Center, University of Washington, Seattle, WA, USA.
authors.forename: Trey
authors.initials: T
authors.lastname: Oxford
authors.affiliation: Washington National Primate Research Center, University of Washington, Seattle, WA, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Nowack
authors.affiliation: Otolaryngology - HNS, University of Washington, Seattle, WA, USA; Electrical Engineering, University of Washington, Seattle, WA, USA.
authors.forename: Kaibao
authors.initials: K
authors.lastname: Nie
authors.affiliation: Otolaryngology - HNS, University of Washington, Seattle, WA, USA; Bioengineering, University of Washington, Seattle, WA, USA.
authors.forename: Jay T
authors.initials: JT
authors.lastname: Rubinstein
authors.affiliation: Otolaryngology - HNS, University of Washington, Seattle, WA, USA; Washington National Primate Research Center, University of Washington, Seattle, WA, USA. Electronic address: jop@uw.edu.
authors.forename: James O
authors.initials: JO
authors.lastname: Phillips
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D017097:Electric Impedance; D004558:Electric Stimulation; D005133:Eye Movements; D008253:Macaca mulatta; D008422:Materials Testing; D023421:Models, Animal; D058117:Neural Prostheses; D009760:Nystagmus, Physiologic; D004856:Postural Balance; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000295:instrumentation*; D013997:Time Factors; D014722:Vestibule, Labyrinth / Q000294:innervation*