title: Artificial balance: restoration of the vestibulo-ocular reflex in humans with a prototype vestibular neuroprosthesis.
abstract: The vestibular system plays a crucial role in the multisensory control of balance. When vestibular function is lost, essential tasks such as postural control, gaze stabilization, and spatial orientation are limited and the quality of life of patients is significantly impaired. Currently, there is no effective treatment for bilateral vestibular deficits. Research efforts both in animals and humans during the last decade set a solid background to the concept of using electrical stimulation to restore vestibular function. Still, the potential clinical benefit of a vestibular neuroprosthesis has to be demonstrated to pave the way for a translation into clinical trials. An important parameter for the assessment of vestibular function is the vestibulo-ocular reflex (VOR), the primary mechanism responsible for maintaining the perception of a stable visual environment while moving. Here we show that the VOR can be artificially restored in humans using motion-controlled, amplitude modulated electrical stimulation of the ampullary branches of the vestibular nerve. Three patients received a vestibular neuroprosthesis prototype, consisting of a modified cochlear implant providing vestibular electrodes. Significantly higher VOR responses were observed when the prototype was turned ON. Furthermore, VOR responses increased significantly as the intensity of the stimulation increased, reaching on average 79% of those measured in healthy volunteers in the same experimental conditions. These results constitute a fundamental milestone and allow us to envision for the first time clinically useful rehabilitation of patients with bilateral vestibular loss.
authors.affiliation: Service of Otorhinolaryngology and Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals , Geneva , Switzerland.
authors.forename: Angelica
authors.initials: A
authors.lastname: Perez Fornos
authors.affiliation: Service of Otorhinolaryngology and Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals , Geneva , Switzerland.
authors.forename: Nils
authors.initials: N
authors.lastname: Guinand
authors.affiliation: Division of Balance Disorders, Department of Otorhinolaryngology and Head and Neck Surgery, Faculty of Health Medicine and Life Sciences, School for Mental Health and Neuroscience, Maastricht University Medical Center , Maastricht , Netherlands.
authors.forename: Raymond
authors.initials: R
authors.lastname: van de Berg
authors.affiliation: Division of Balance Disorders, Department of Otorhinolaryngology and Head and Neck Surgery, Faculty of Health Medicine and Life Sciences, School for Mental Health and Neuroscience, Maastricht University Medical Center , Maastricht , Netherlands.
authors.forename: Robert
authors.initials: R
authors.lastname: Stokroos
authors.affiliation: Translational Neural Engineering Laboratory, Center for Neuroprosthetics, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne , Lausanne , Switzerland ; The BioRobotics Institute, Scuola Superiore Sant'Anna , Pisa , Italy.
authors.forename: Silvestro
authors.initials: S
authors.lastname: Micera
authors.affiliation: Division of Balance Disorders, Department of Otorhinolaryngology and Head and Neck Surgery, Faculty of Health Medicine and Life Sciences, School for Mental Health and Neuroscience, Maastricht University Medical Center , Maastricht , Netherlands.
authors.forename: Herman
authors.initials: H
authors.lastname: Kingma
authors.affiliation: Service of Otorhinolaryngology and Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals , Geneva , Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Pelizzone
authors.affiliation: Service of Otorhinolaryngology and Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals , Geneva , Switzerland.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Guyot
keywords: balance; rehabilitation; sensory neuroprostheses; vestibular implant; vestibulo-ocular reflex