Study Stopped
Due to COVID-19 pandemic during the 1year of grant funding (2019-2020), no new patients were implanted with the vestibular prosthetic device and enrolled in this study at the University of Geneva study site.
Vestibular Implants Tested in Human Subjects
1 other identifier
interventional
N/A
2 countries
3
Brief Summary
The goal of this study is to improve the vestibular implant's ability to reduce the vestibular-dependent perceptual, postural, and visual symptoms that affect patients with severe peripheral vestibular damage. The long-term research plan is focused on exploring the three questions which must be answered to assess the clinical utility of a vestibular implant (VI) in vestibulopathic patients - i) how can information transfer from the VI sensors to the brain be optimized; ii) how does the three-dimensional angular velocity information provided by the VI interact in the brain with other sensorimotor (vision, otolith, efferent) signals; and iii) how effectively does the VI alleviate the behavioral deficits and subjective symptoms experienced by patients with severe vestibular damage. The current study will be used to focus on two key subsets of these questions. Over one year, the investigators will study approximately 5 patients who have severe bilateral vestibular damage and functioning VI's, which will focus on aim 1: how the angular velocity information sensed by the VI can be optimally transferred to the brain; and aim 2: how effectively the VI improves the clinical status of vestibulopathic patients when they receive acute and sub-acute (3 days) motion-modulated stimulation. In sum, the investigators aim to improve the efficacy of the VI in human subjects by developing new knowledge about how the brain processes motion cues provided by the VI and correlating this information with behavioral outcomes.
Trial Health
Trial Health Score
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Started Aug 2019
3 active sites
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
August 1, 2019
CompletedPrimary Completion
Last participant's last visit for primary outcome
January 31, 2021
CompletedStudy Completion
Last participant's last visit for all outcomes
January 31, 2021
CompletedFirst Submitted
Initial submission to the registry
May 17, 2021
CompletedFirst Posted
Study publicly available on registry
May 27, 2021
CompletedJuly 1, 2024
June 1, 2024
1.5 years
May 17, 2021
June 27, 2024
Conditions
Keywords
Outcome Measures
Primary Outcomes (13)
Changes in Postural Sway Thresholds
Changes in threshold for postural sway, measured using IMUs (inertial measurement unit) placed on the upper back, head, and torso, will be assessed before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following motion-modulated stimulation.
3 days
Changes in Postural Sway Amplitudes
Changes in amplitude in postural sway, measured using IMUs (inertial measurement unit) placed on the upper back, head, and torso, will be assessed before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following motion-modulated stimulation.
3 days
Changes in Gait dynamics
Changes in gait dynamics, measured using IMUs (inertial measurement unit) placed on the upper back, head, each ankle, and torso during various physical therapy walking tasks (Functional Gait Analysis), will be assessed before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following motion-modulated stimulation.
3 days
Changes in Vestibular Ocular Reflex (VOR) Amplitude
This reflex which moves the eyes in response to head movement and is driven by the sensors in the inner ear. Participants will walk in place while fixating on a cyclopean eye-centered near target (0.5m) and a far target (10m) for 60sec each. A lightweight infrared eye tracker with built in 6 degree of freedom IMU (eyeseecam) will be used to measure eye and head movements together. The amplitude or 'gain' (eye velocity divided by head velocity) is assessed before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following 8hrs of motion-modulated stimulation. Low gain is associated with impaired VOR.
3 days
Changes in Vestibular Ocular Reflex (VOR) Threshold
This reflex which moves the eyes in response to head movement and is driven by the sensors in the inner ear. Participants will wear a lightweight infrared eye tracker with built in 6 degree of freedom IMU (eyeseecam). Investigators will gently rotate the participant about the yaw-axis while measuring eye and head movements together. The velocity threshold for VOR is quantified before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following motion-modulated stimulation.
3 days
Changes in motion perception in yaw
Perception of head motion and orientation relative to gravity is measured by a continuous task during yaw rotation where the goal is to keep a light pointing in the direction of the start position/straight ahead. The task requires constant corrections because the light's orientation shifts randomly (based on integrated Brownian noise) and accelerates when a wheel is turned, resulting in overshooting errors. This method, a variant of the Critical Control Task used in humans, is an accurate way to capture perceived head motion. Motion perception during yaw-rotation will be assessed before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following 8hrs of motion-modulated stimulation.
3 days
Changes in motion perception orientation in roll
Perception of head motion and orientation relative to gravity is measured by a continuous subjective-visual-vertical (SVV) task where the subject uses a small steering wheel to keep a light bar orientated parallel to the perceived earth-vertical. The task requires constant corrections because the light bar's orientation shifts randomly (based on integrated Brownian noise) and accelerates when the wheel is turned, resulting in overshooting errors. This method, a variant of the Critical Control Task used in humans, is an accurate way to capture perceived head orientation. The 'perceived upright' is assessed before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following 8hrs of motion-modulated stimulation.
3 days
Changes in angular error during a navigation task
Participants will perform a path integration or 'complete the triangle' virtual reality task - angular error of responses is measured before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following 8hrs of motion-modulated stimulation. Greater angular error and variability of angular error is associated with worse visual-spatial memory.
3 days
changes in dizziness handicap index score
Participants will fill out the dizziness handicap index questionnaire before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following 8hrs of motion-modulated stimulation. It is scored 0 to 100 with high scores indicating greater subjective dizziness and disbalance.
3 days
changes in activities-specific balance confidence score
Participants will fill out the activities-specific balance confidence questionnaire before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following 8hrs of motion-modulated stimulation. It is scored from 0-100% with lower scores showing less confidence in balance and more subjective dizziness.
3 days
changes in oscillopsia functional impact scale score
Participants will fill out the oscillopsia functional impact scale before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following 8hrs of motion-modulated stimulation. It is scored from 0 to 215 in 5 point increments.
3 days
changes in reported quality of life
Quality of life will be assessed by participants filling out the short form-36 health survey (scored 0 to 100 points) before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following 8hrs of motion-modulated stimulation.
3 days
changes in cognitive impairment - visual-spatial function
Cognitive impairment will be assessed by participants completing a neuropsychological test battery with a focus on visual-spatial tasks before prosthetic stimulation, immediately after the prosthesis is activated, and daily for 3 days following 8hrs of motion-modulated stimulation. More errors and time to complete the tasks in the battery are associated with visual-spatial memory and function impairment.
3 days
Study Arms (1)
Vestibular & Cochlear Implant Patients
EXPERIMENTAL* scheduled for CI surgery because of deafness * a minimum of five year history of documented absence of auditory and vestibular function, based on review of their audiograms and vestibular tests. * Specific vestibular criteria are: peak ice water caloric response of less than 3 deg/s for each ear; yaw VOR time constant \< 3.0 sec and gain \< 0.25; and reduced head impulse gain (\<0.25) for all canal planes. * Specific audiographic criteria: 80dB or greater sensorineural hearing loss in both ears
Interventions
The intervention is a vestibular prosthesis which our collaborators at the University of Geneva are implanting into the inner ear in deaf patients without vestibular function who are receiving a cochlear implant. The vestibular implant (VI) has three rate sensors and senses angular head velocity in three dimensions and provides this information to the brain by stimulation the afferent nerves innervating the three semicircular canals. Our goal is to use the VI to better understand how the brain processes this prosthetic information and uses it to generate meaningful behavioral responses including eye movements, postural control, and perception.
VI subjects will be studied before the implant is activated (pre) and then after it is turned on (acute On); this will take about 2 hrs. Then they will have 8 hours of motion-modulated VI stimulation while they actively explore the hospital environment, after studies will be repeated (chronic On). Each set of outcome experiments will be performed twice, once with and once without low-levels of stochastic noise added to the VI stimulation provided for the 8-hour period. The noise amplitude is tailored to each patient to maximize stochastic resonance so extraction \& integration of spatial signal provided by the VI will always be the first experiment, but the order of the subsequent outcome sessions (active/passive head rotations, tilt/translation motion discrimination and VOR behavioral changes \& postural control) will be randomized. VI subjects will participate in 4 full-day sessions, each separated by at least a month.
Eligibility Criteria
You may qualify if:
- scheduled for cochlear implant CI surgery because of deafness
- minimum of five year history of documented absence of auditory \& vestibular function, based on review of their audiograms \& vestibular tests
- Specific vestibular criteria are: peak ice water caloric response of less than 3 deg/s for each ear; yaw VOR time constant \< 3.0 sec and gain \< 0.25; and reduced head impulse gain (\<0.25) for all canal planes.
- Specific audiographic criteria: 80dB or greater sensorineural hearing loss in both ears
You may not qualify if:
- pregnant
- not scheduled for cochlear implant/vestibular implant surgery
- unable to walk 50m
- other neurological disorder (other than migraine), otologic disease (other than presbycusis)
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Massachusetts Eye and Ear Infirmarylead
- Ohio State Universitycollaborator
- University of Geneva, Switzerlandcollaborator
Study Sites (3)
Massachusetts Eye and Ear Infirmary
Boston, Massachusetts, 02114, United States
Ohio State University
Columbus, Ohio, 432120000, United States
Universite de Geneve Hospital (UNIGE)
Geneva, 1211- CH-0, Switzerland
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- NA
- Masking
- NONE
- Purpose
- BASIC SCIENCE
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Associate Professor, Otolaryngology and Neurology; Director, Jenks Vestibular Laboratory
Study Record Dates
First Submitted
May 17, 2021
First Posted
May 27, 2021
Study Start
August 1, 2019
Primary Completion
January 31, 2021
Study Completion
January 31, 2021
Last Updated
July 1, 2024
Record last verified: 2024-06