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

Nils Guinand

Status: Unknown

Conditions: Bilateral Vestibulopathy; Bilateral Vestibular Loss; Vestibular Disorder

Treatments: Diagnostic Test: Bilateral vestibulopathy Patients (BV); Diagnostic Test: Unilateral vestibulopathy Patients (UV); Procedure: Electrical stimulation of the auditory system; Procedure: Electrical stimulation of the vestibular system

Study type: Interventional

Funder types: Other

Identifiers

NCT05246553

NAC 11-080 CER 11-129

Details and patient eligibility

About

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.

Full 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).

Enrollment: 52 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Patients implanted with a vestibular implant showing neither auditory function nor vestibular one.
• Control group of patients implanted with a cochlear implant and presenting a normal vestibular function.
• Control group of patients with bilateral vestibular loss.
• Control group of patients with unilateral vestibular loss and finally
• Control group of healthy subjects with normal auditory and vestibular functions.

All sujbects included in the study will be older than 18 years old.

Exclusion criteria

• Children
• Patients suffering from blindness,
• Patients suffering from major ophtalmologic damage
• Patients suffering from neurologic disorder.

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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52 participants in 5 patient groups

Modified cochlear implant recipients

Experimental group

Description:

Patients suffering from severe to profound hearing loss and severe bilateral vestibulopathy implanted with a modified cochlear implant providing 1 to 3 extracochlear electrodes implanted in proximity to the ampullary branches of the vestibular nerve (vestibular electrodes). All experiments will be carried out while the vestibular electrodes are inactive, and while electrical stimulation is delivered to one or several vestibular electrodes, with and without concurrent cochlear stimulation.

Treatment:

Procedure: Electrical stimulation of the vestibular system

Procedure: Electrical stimulation of the auditory system

Cochlear Implant Patients (CI)

Active Comparator group

Description:

Unilateral or bilateral cochlear implant recipients with normal vestibular function documented within the clinical follow up of their cochlear implant, and without previous history of vestibular symptoms or complaints.

Treatment:

Procedure: Electrical stimulation of the auditory system

Bilateral vestibulopathy Patients (BV)

Active Comparator group

Description:

Patients with documented diagnosis of bilateral vestibulopathy, according to the guidelines of the Barany society (Strupp et al., Journal of Vestibular Research, vol. 27, no. 4, pp. 177-189, 2017).

Treatment:

Diagnostic Test: Bilateral vestibulopathy Patients (BV)

Unilateral vestibulopathy Patients (UV)

Active Comparator group

Description:

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).

Treatment:

Diagnostic Test: Unilateral vestibulopathy Patients (UV)

Healthy Subjects (HS)

No Intervention group

Description:

Normal auditory functiona and without previous auditory or vestibular symptoms or complaints. Normal vestibular function documented with the video-head impulse test.