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RECRUITING

NCT07627087

Spatial Orientation, Navigation, and Neuropsychologic Function in Patients With Vestibular Implant

Sponsor: Massachusetts Eye and Ear Infirmary

View on ClinicalTrials.gov

Summary

The vestibular system, located in the inner ear, provides information to the brain information about how head acceleration and orientation relative to gravity. Damage to the vestibular system is usually permanent and can contribute to a lower quality of life. The goal of this research is to to examine how vestibular implants (VI) may improve performance of cognitive tasks in patients with severe vestibular damage. These higher-level cognitive behaviors include (1) orientation relative to gravity, (2) navigation, and (3) neuropsychologic function. VI patients will be tested in these three cognitive domains across study sessions: pre-stimulation (VI implanted but stimulation OFF), following chronic stimulation (12 days, VI-ON), and then again 1 month later with the VI turned off. There will be both "true" stimulation experiments during which the VI will provide motion-modulated stimulation and also "placebo" stimulation (no motion cues, tonic stimulus). The order of these experiments will be randomized and separated by 3 months. Researchers will compare VI data in the three cognitive domains (spatial orientation, navigation, \& neuropsychologic function) with control data from non-implanted bilateral vestibular loss (BVL) and unilateral vestibular loss (UVL) patients and normal subjects.

Official title: Vestibular Implant Tested in Patients With Peripheral Vestibular Damage: Effects on Spatial Orientation, Navigation, and Neuropsychologic Function

Key Details

Gender

All

Age Range

18 Years - 80 Years

Study Type

INTERVENTIONAL

Enrollment

Start Date

2026-01-22

Completion Date

2029-07-31

Last Updated

2026-06-04

Healthy Volunteers

Conditions

Vestibular Dysfunction Bilateral Vestibular Loss Vestibular Implant

Interventions

DEVICE

vestibular implant stimulation

Two types of stimulation are used, tonic + motion-modulated ("true") \& tonic-only ("placebo") stimulation; order is randomized. The VI stimulation period prior to testing is 12 days. For the experiments, the VI is connected to the head-mounted prosthetic circuit and then stimulation is activated. The stimulation unit is the current-balanced biphasic pulse, and the pulse amplitude for each subject is determined through a tuning procedure. Experiments start with an adaptation to tonic baseline stimulation with the head stationary (\~30 min). Motion-modulated stimulation employs 3 angular velocity sensors (one aligned with the sensitive axis of each canal), the transduced head velocity signal is high-pass filtered to simulate normal canal dynamics, and filtered head velocity is used to modulate the strength (magnitude, rate) of the electrical stimulation provided by the corresponding implanted electrode. Stimulation strength adjusts for head rotations that change canal afference.

1. Patients receiving vestibular implants at UNIGE: Their inclusion criteria are defined as follows: * Deaf, scheduled for CI surgery * Minimum of five year history of documented absence of bilateral auditory and vestibular function, based on review of their audiograms and vestibular tests. * Vestibular testing consistent with BVL * No neurologic disease. note: these patients are recruited and implanted by the group at the University of Geneva Hospital (UNIGE) as part of their ongoing research. The study team are not involved in any way with the decision to surgically implant patients with cochlear or vestibular implants, nor are the researchers involved in any way with pre- or post-operative clinical care. The researchers only involvement is to perform the cognitive tests before, during, and after relatively short periods of stimulation using the vestibular implant (VI) 2. Vestibular patients tested at MEE: vestibular testing consistent with unilateral or bilateral vestibular damage. Both aspects of the study share the same exclusion criteria: Exclusion Criteria: * No known neurologic or otologic disease other than the vestibular and auditory deficits noted above. * Pregnancy. Pregnant women and women up to 4 months postpartum will be excluded because of the known effects and unknown potential effects of pregnancy on sensory function. * Body weight \>250 lbs (due to motion device safety limits) * The chronic use of vestibular suppressant medication (benzodiazepine, antihistamine, anticholinergic) * Inability to stand or walk unassisted. * Blindness. * Unstable medical condition. * Orthopedic or musculoskeletal injuries/conditions that affect gait or balance. * Ongoing neck or spinal pain/injuries or recent history of neck or spinal surgery * Amputation, musculoskeletal deformity, or significant leg-length discrepancy * A history of severe head trauma. * Any major psychiatric disorder (e.g., psychosis, schizophrenia, panic disorder), not including anxiety or depression. * Severe heart or pulmonary conditions * Active cancer for which chemo-/radiation therapy is being received.

Locations (1)

Universite de Geneve

Geneva, Switzerland