NCT05246553

Electrical Stimulation of the Peripheral Vestibular System in Order to Develop a Vestibular Implant

• Status: Unknown
• Phase: N/A
• Study type: Interventional
• Enrollment: 52 (estimated)
• Sponsor: Nils Guinand · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

This study has three main goals (1) to explore the effects of electrical stimulations of the peripheral vestibular system(2) to assess the potential of this technique to rehabilitate basic vestibular functions in patients with severe bilateral vestibulopathy, and (3) to take advantage of the unprecedented experimental paradigm provided by the vestibular implant to increase our fundamental knowledge on the contribution of peripheral vestibular function to posture, gait and higher order sensory functions, mechanisms that remain poorly understood.

Detailed description

The investigators will carry out a thorough investigation of the effects of electrical stimulation on vestibular and auditory function in a group of patients implanted with a modified cochlear implant providing extracochlear electrodes implanted in the vicinity of the of the ampullary nerve branches. These results will be compared to similar measurements carried out in a group of age and sex-matched healthy controls, in a group of patients with bilateral and unilateral vestibulopathy, and also in a group of patients implanted with a cochlear implant and normal vestibular function. The protocol comprises the following specific measurements: 1. Clinical evaluation of auditory function: pure-tone and speech audiometry. 2. Clinical evaluation of vestibular function: clinical evaluation of the vestibulo-ocular reflex (e.g., video-nystagmography, video-head impulse tests), and of the otolithic function (vestibular evoked myogenic potentials). 3. Dynamic visual acuity: loss of visual acuity while walking in a treadmill at controlled speed, compared to the static (standing in place) of the subject. 4. Auditory and vestibular brainstem evoked potentials. 5. Electroencephalography. 6. Temporal Binding Window: maximal time interval separating two different types of sensory stimuli (visual, auditory and vestibular) within which the subject still perceives them as simultaneous. 7. Psychophysical motion detection tests: motion perception thresholds measured in a platform allowing specific and smooth motion profiles in 3 linear and 3 angular dimensions. 8. Gait and posture: functional gait assessment, postural sway in conditions providing accurate or conflicting sensory (e.g., vestibular, visual, proprioceptive) information. 9. Spatial navigation in real and virtual reality environments (e.g. Morris water maze, standardized clinical environment). 10. Monitoring of the autonomous nervous system: standard, non-invasive clinical investigations of cardiovascular, ophthalmic, secretory, or metabolic functions (e.g., blood pressure, heart rate, pupillary reflex).

Conditions

• Vestibular Disorder
• Bilateral Vestibulopathy
• Bilateral Vestibular Loss

Interventions

Type	Name	Description
PROCEDURE	Electrical stimulation of the vestibular system	Patients are implanted with a modified cochlear implant (CI) which comprises one to three extracochlear electrodes that are placed in the proximity of vestibular afferents (i.e., vestibular nerves or the ampullae of each semicircular canal), and an intracochlear array. Trains of electrical stimulation in the form of charge-balanced, biphasic pulses can be delivered through each of the implanted electrodes (cochlear or vestibular) and modulated via computer-controlled signals, audio signals (captured with a microphone) or by signals captured by head-mounted motion sensors.
PROCEDURE	Electrical stimulation of the auditory system	A cochlear implant (CI) is a device providing a sense of sound to a person who suffers from severe to profound sensorineural hearing loss. A CI comprises the following parts, a microphone (capturing the sound from the environment), a speech processor (receiving and encoding the sounds captured by the mircophone), a transmitter-receiver antenna pair (transmitting the information from the external to the implanted components), an implanted stimulator (converting the signal into a tonotopically arranged set of electrical pulses) and an electrode array inserted in the cochlea that will deliver the electrical pulses to different portions of the auditory nerve. Trains of electrical stimulation in the form of charge-balanced, biphasic pulses can be delivered through each of the electrodes in the cochlear array and modulated via computer-controlled signals or audio signals (captured with a microphone).
DIAGNOSTIC_TEST	Bilateral vestibulopathy Patients (BV)	Diagnosis established on the basis of the consensus document of the Classification Committee of the Bárány Society (Strupp et al., Journal of Vestibular Research, vol. 27, no. 4, pp. 177-189, 2017).
DIAGNOSTIC_TEST	Unilateral vestibulopathy Patients (UV)	Patients with documented diagnosis of unrecovered unilateral vestibulopathy, consistent with the current classification of vestibular disorders of the Bárány Society (www.jvr-web.org/ICVD.html).

Timeline

• Start date: 2011-12-01
• Primary completion: 2023-12-31
• Completion: 2023-12-31
• First posted: 2022-02-18
• Last updated: 2022-02-18

Locations

1 site across 1 country: Switzerland