The document summarizes the history and development of vestibular implants. It discusses early experiments in the 19th century that provided electrical stimulation to induce vertigo. It then reviews the development of modern vestibular implants, including the first implantation in humans in 2007 by the Maastricht-Geneva group. Several types of vestibular implants are described, including vestibulocochlear implants, vestibular pacemakers, and multichannel vestibular implants. Outcomes of electrical vestibular stimulation and challenges are also discussed.

1. Vestibular Implant
Sasan Dabiri
Otology/Neurotology Fellow, Department of Otolaryngology
University Health Network, University of Toronto
November 2020

2. Background
• In the early 19th century, Purkynje provided low-frequency electrical
stimulation between the left and right ears to induce vertigo
• Ewald in 1892 reported vestibular-evoked head movements using
electrical stimulation in pigeons
• Cohen and Suzuki indicated in the 1960s that eye movements could be
evoked by electrically stimulating the ampullary and otolith nerves in
animals
• Curthoys and Markham showed the evidence for convergence of
ampullary and otolith input onto single vestibular neurons in response to
both natural and electrical vestibular nerve stimulation

3. Background
• Gong and Merfeld: the first in restoring lost vestibular function using a
vestibular implant in Guinea pig in 2000
- Nystagmus subsided after 1 day with continuous stimuli
- Nystagmus in reversed direction with shorter duration when off
• Maastricht-Geneva group: The first implantation in human in 2007
- Only 27 min nystagmus after turning on
- Only 3 min opposite nystagmus after turning off
without major discomfort and
the possibility of controlled eye movements with a unilateral prosthesis

4. Suitable Implantation Site
• Extra-labyrinthine
• Post. ampullary N.
• Lat. & Sup. ampullary N.
• Trancanal approach
• Local anesthesia
Kos, et al. Otol Neurotol, 2006: 542Feigl, et al. Otol Neurotol, 2009: 586

5. Suitable Implantation Site
• Extra-labyrinthine
• Intra-labyrinthine
• Mastoidectomy
Van de Berg, et al. Front Neurol, 2012:18

6. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibulocochlear Implant (2007)
• Maastricht-Geneva group
Commercially available CI (Med El):
1–3 vestibular electrodes for the SCCs,
together with an intracochlear electrode
Guinand, et al. ORL, 2015: 227

7. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibulocochlear Implant (2007)
• Maastricht-Geneva group
13 patients with bilateral vestibular areflexia and profound SNHL have been implanted
(extra- or intra-labyrinthine technique)
Stimulation with this vestibulocochlear implant resulted in the eVOR:
• frequency-dependent behavior was detected for a broad frequency range like the natural
frequency dependency of the angular VOR
• The variability in artificially evoked vestibular responses can be partially explained by the
neural convergence as both the artificially and naturally stimulated neurons

8. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibulocochlear Implant (2007)
• Maastricht-Geneva group
• Vestibular Pacemaker (2013)
• University of Washington
Counteracting the symptoms of Meniere’s D.
(implanted in the perilymphatic space)
Golub, et al. Otol Neurotol, 2013: 136

9. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibulocochlear Implant (2007)
• Maastricht-Geneva group
• Vestibular Pacemaker (2013)
• University of Washington
Only the results of one patient is reported:
• During the attack (which occurred while the patient was at home), the patient cycled through
the stimulation programs of the modified CI
(programs: increase in current intensity steps of 25 μA)
• The first program suppressed the MD-induced symptoms, but the second program worsened
the vertigo, as did turning the device off during the MD attack ( & loosing hearing )

10. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibulocochlear Implant (2007)
• Maastricht-Geneva group
• Vestibular Pacemaker (2013)
• University of Washington
• Multichannel Vestibular Implant (2016)
• Johns Hopkins University
• Has built-in gyroscopes and accelerometers capable of
sensing and encoding 3D rotations and linear accelerations
• Fifty stimulating electrode contacts are distributed over
three electrode shanks
(not include an intracochlear electrode array) Hageman, et al. J Med Device, 2016: 030923

11. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibulocochlear Implant (2007)
• Maastricht-Geneva group
• Vestibular Pacemaker (2013)
• University of Washington
• Multichannel Vestibular Implant (2016)
• Johns Hopkins University
• Otolith Implant (2017)
• University of Las Palmas
• temporarily inserting up to 3 apical electrodes of a
standard CI in the vestibule in 3 MD patients (unilat.):
• Result: Direct otolith stimulation with single biphasic
pulses evoked vestibular ECAPs and ocular VEMPs

12. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibular Co-Stimulation by a Cochlear Implant
• the currents from the CI spread to the surrounding vestibular structures and facial nerve

13. Sluydts, et al. Audiol Neurotol, 2020: 6
Vestibular
Stimulation
- Outcomes

14. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibular Co-Stimulation by a Cochlear Implant

15. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibular Co-Stimulation by a Cochlear Implant
BalanCI
• Use of both the gyroscopes and accelerometers
• Provides head-referenced spatial information through
bilateral CI stimulation
• In the auditory feedback condition, the child receives a
distinct tone or click when the head deviates
sufficiently from the center of gravity. These sounds are
translated into electrical pulses by connecting to the CI
via commercially available adaptors. Wolter, et al. Audiol Neurotol, 2020: 60

16. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibular Co-Stimulation by a Cochlear Implant
• Galvanic Vestibular Stimulation
• Transient transmastoid stimulation
the most common type: stochastic stimuli (noise)
• Irregular afferents have a significantly lower threshold for GVS than the regular afferents

17. Vestibular Stimulation
• Electrical Vestibular Stimulation with a Vestibular Implant
• Vestibular Co-Stimulation by a Cochlear Implant
• Galvanic Vestibular Stimulation
• A huge difference compared to the unilaterally implanted canal implant is that
GVS can provide bilateral vestibular information simultaneously to vestibule
So, baseline adaptation is not needed
• Drawback: local skin irritation and symptoms

18. Basic Principles and Challenges of EVS with a VI
• Restoration of Spontaneous Firing Rate
• Motion Modulation (unilateral implant in bilateral problems)
• Acute or Chronic Stimulation
• Central Vestibular Convergence in the Vestibular Nuclei and
Multisensory Integration
• Preservation of the (Residual) Hearing (conductive/sensorineural)
• Preservation and Influence of the Residual Vestibular Function

19. References
• Azevedo YJ, Ledesma ALL, Pereira LV, Oliveira CA, Bahmad Junior F. Vestibular implant: does it really work? A systematic review. Braz J Otorhinolaryngol. 2019 Nov-
Dec;85(6):788-798
• Feigl GC, Fasel JH, Anderhuber F, Ulz H, Rienmüller R, Guyot JP, Kos IM. Superior vestibular neurectomy: a novel transmeatal approach for a denervation of the superior and
lateral semicircular canals. Otol Neurotol. 2009 Aug;30(5):586-91
• Fornos AP, van de Berg R, Armand S, Cavuscens S, Ranieri M, Crétallaz C, Kingma H, Guyot JP, Guinand N. Cervical myogenic potentials and controlled postural responses
elicited by a prototype vestibular implant. J Neurol. 2019 Sep;266(Suppl 1):33-41
• Golub JS, Ling L, Nie K, Nowack A, Shepherd SJ, Bierer SM, Jameyson E, Kaneko CR, Phillips JO, Rubinstein JT. Prosthetic implantation of the human vestibular system. Otol
Neurotol. 2014 Jan;35(1):136-47
• Guinand N, van de Berg R, Cavuscens S, Stokroos RJ, Ranieri M, Pelizzone M, Kingma H, Guyot JP, Perez-Fornos A. Vestibular Implants: 8 Years of Experience with Electrical
Stimulation of the Vestibular Nerve in 11 Patients with Bilateral Vestibular Loss. ORL J Otorhinolaryngol Relat Spec. 2015;77(4):227-240
• Guyot JP, Perez Fornos A. Milestones in the development of a vestibular implant. Curr Opin Neurol. 2019 Feb;32(1):145-153
• Hageman KN, Chow MR, Boutros PJ, Roberts D, Tooker A, Lee K, Felix S, Pannu SS, Della Santina CC. Design of a Vestibular Prosthesis for Sensation of Gravitoinertial
Acceleration. J Med Devices. September 2016; 10(3): 030923
• Kos MI, Feigl G, Anderhuber F, Wall C, Fasel JH, Guyot JP. Transcanal approach to the singular nerve. Otol Neurotol. 2006 Jun;27(4):542-6
• Perez Fornos A, Cavuscens S, Ranieri M, van de Berg R, Stokroos R, Kingma H, Guyot JP, Guinand N. The vestibular implant: A probe in orbit around the human balance
system. J Vestib Res. 2017;27(1):51-61
• Sluydts M, Curthoys I, Vanspauwen R, Papsin BC, Cushing SL, Ramos A, Ramos de Miguel A, Borkoski Barreiro S, Barbara M, Manrique M, Zarowski A.
Electrical Vestibular Stimulation in Humans: A Narrative Review. Audiol Neurootol. 2020;25(1-2):6-24
• van de Berg R, Guinand N, Guyot JP, Kingma H, Stokroos RJ. The modified ampullar approach for vestibular implant surgery: feasibility and its first application in a human
with a long-term vestibular loss. Front Neurol. 2012 Feb 20;3:18
• van de Berg R, Guinand N, Ranieri M, Cavuscens S, Khoa Nguyen TA, Guyot JP, Lucieer F, Starkov D, Kingma H, van Hoof M, Perez-Fornos A. The Vestibular Implant Input
Interacts with Residual Natural Function. Front Neurol. 2017 Dec 14;8:644
• Wolter, Gordon KA, Campos JL, Vilchez Madrigal LD, Pothier DD, Hughes CO, Papsin BC, Cushing SL. BalanCI: Head-referenced cochlear implant stimulation
improves balance in children with bilateral cochleovestibular loss. Audiol Neurootol. 2020;25(1-2):60-71