Bilateral vestibulopathy is a heterogeneous disorder resulting in many disabling symptoms, including imbalance, oscillopsia, reduced mobility, and increased risk of falling. It has even been associated with cognitive impairments. Unfortunately, the prognosis is poor and currently available treatment options have very low efficacy.

Vestibular implants are implantable devices that attempt to partially restore vestibular function to patients with severe bilateral vestibulopathy of peripheral origin, using electrical currents. There have been substantial research efforts, first in animals and more recently in humans, towards the development of vestibular implants. Our group, the Geneva-Maastricht team, developed an original concept based on a modified cochlear implant. This device, developed in close collaboration with MED-EL (Innsbruck, Austria), provides 1 to 3 extra-cochlear electrodes which are implanted in the vicinity of vestibular afferents in addition to the “standard” cochlear implant array. We started implantations in humans in 2007 and, to date, 13 patients with severe bilateral vestibulopathy were implanted with these prototype devices without surgical or medical complications.

Special surgical techniques have been developed for safe implantation of these devices and their feasibility has been demonstrated in human subjects. Humans have demonstrated surprising adaptation capabilities to the artificial vestibular signal. Successful restoration of the vestibulo-ocular reflex in the mid- to high- frequency range has been demonstrated using standard clinical tests (rotatory chair and video-head impulse test). We also showed that it is possible to activate the vestibulo-collic reflex using measures of cervical myogenic vestibular evoked potentials. Controlled postural responses could also be obtained with our prototype vestibular implant device. Finally, visual abilities in dynamic settings were restored with the vestibular implant. The latter is a major step forward, providing the first ever demonstration of useful rehabilitation of this patient population.

Results obtained so far in humans are very encouraging. We hope that the increasing interest in this field and the substantial research efforts allocated lead to a clinical application in the near future. It should also be mentioned that the vestibular implant opens new possibilities for exploring several fundamental issues: balance function, the adaptive capacities of the brain, the processes of temporal integration of sensory information necessary for equilibrium, and probably for better understanding vestibular physiology and vestibular disorders. Therefore, the vestibular implant opens new perspectives, not only as an effective therapeutic tool, but also pushes us to go beyond current knowledge and well established clinical concepts.