Long Term Outcomes After Vestibular Implantation

Although cochlear implants can restore hearing to individuals who have lost cochlear hair cell function, there is no widely available, adequately effective treatment for individuals suffering chronic imbalance, postural instability and unsteady vision due to bilateral vestibular hypofunction. Prior research focused on ototoxic cases has demonstrated that electrical stimulation of the vestibular nerve via a chronically implanted multichannel vestibular implant can partially restore vestibular reflexes that normally maintain steady posture and vision; improve performance on objective measures of postural stability and gait; and improve patient-reported disability and health-related quality of life. This single-arm open-label study extends that research to evaluate outcomes for up to 8 individuals with non-ototoxic bilateral vestibular hypofunction, yielding a total of fifteen adults (age 22-90 years at time of enrollment) divided as equally as possible between ototoxic and non-ototoxic cases.

Study Overview

• Status: Recruiting
• Conditions: Labyrinth Diseases; Vestibular Diseases; Sensation Disorders; Bilateral Vestibulopathy; Gentamicin Ototoxicity; Aminoglycoside Toxicity; Bilateral Vestibular Hypofunction; Bilateral Vestibular Deficiency; Other Disorders of Vestibular Function
• Intervention / Treatment: Device: Labyrinth Devices MVI™ Multichannel Vestibular Implant System

Detailed Description

There is no widely available, adequately effective treatment for individuals suffering chronic imbalance, postural instability and unsteady vision due to loss of semicircular canal function despite vestibular rehabilitation exercises. The experience of 15 adults with bilateral vestibular hypofunction who underwent unilateral surgical placement of a vestibular implant and have received continuously motion-modulated electrical stimulation of the vestibular nerve for >6 months revealed vestibular implantation (VI) and motion-modulated stimulation can partially restore vestibular sensation and reflexes that normally maintain steady posture and vision. This study will examine long-term outcomes after vestibular implantation. Within constraints on power and/or minimum detectable effect size due to limits on the number of study participants permitted under IDE G150198, the study will test the following hypotheses regarding unilateral vestibular implantation, activation and long-term (≥3 years) continuous/daily use:

1. It is safe, as determined by incidence of serious unanticipated adverse device-related events and as further quantified by proportions of:

   1. implanted ears with preservation of 4-frequency pure tone average for 0.5,1,2,4 kHz air-conducted audiometric detection thresholds ≤ 50 decibel (dB) HL and ear-specific speech discrimination ≥50% (consistent with Class A or B per American Academy of Otolaryngology-Head and Neck Surgery 1995 guidelines 13 ) or ≤ 30 dB change from preoperative baseline (if preoperative baseline is ≥20 dBHL) and ear-specific speech discrimination ≤30% worse than preoperative baseline (if preoperative baseline is ≤80%)
   2. participants with preservation of useful sound-field hearing by the above criteria, and
   3. implanted ears with preservation of otolith endorgan function, if present pre-operatively
2. It is tolerable, as quantified by duration of compliance with use.
3. It is efficacious, as defined by nonzero improvement with respect to preoperative baseline gait stability as quantified by Dynamic Gait Index (DGI) and vestibulo-ocular reflex gain during passive head impulse rotation (VHITG) .

• Study Type: Interventional
• Enrollment (Estimated): 32
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Kelly Lane; Phone Number: 410-502-8047; Email: vestibularimplant@jhmi.edu
• Study Contact Backup: Name: Charles C Della Santina, MDPhD; Phone Number: 410-502-8047; Email: cds@jhmi.edu

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21287
      • Recruiting
      • Johns Hopkins School of Medicine
      • Contact: Charles C Della Santina, MDPhD; Phone Number: 410-502-8047; Email: vestibularimplant@jhmi.edu
      • Contact: Lauren N Trainer, BS; Phone Number: 410-502-5129; Email: vestibularimplant@jhmi.edu
      • Principal Investigator: John P Carey, MD
      • Sub-Investigator: Charles C Della Santina, MDPhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Study Population

Potential participants will be recruited from the existing participant pool of individuals enrolled and implanted under study protocols NA_00051349, IRB00335294 or IRB00346924.

Recruitment to meet equitable demographic distribution targets is a focus of effort and a consideration in the study teams review of applications for those study protocols.

Description

Inclusion Criteria

• Adults older than 22 years old who
• have previously been enrolled in Johns Hopkins University Institutional Review Board protocol NA_00051349, IRB00335294 or IRB00346924 and
• have previously been implanted with a vestibular implant under FDA IDE G150198

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Vestibular Implant; Up to 32 participants will undergo implantation, activation and deactivation of a Labyrinth Devices MVI™ Multichannel Vestibular Implant System (MVI)	Device: Labyrinth Devices MVI™ Multichannel Vestibular Implant System; Continuously motion-modulated stimulation delivered by a vestibular implant already implanted under a prior study protocol (Labyrinth Devices MVI™ Multichannel Vestibular Implant System); Other Names: Motion-modulated stimulation delivered by a vestibular implant already implanted under a prior study protocol

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PM1.1: Dynamic Gait Index (DGI)18 during motion-modulated implant stimulation at 4 years post-implantation, relative to pre-operative baseline, aggregated across all implant users.	DGI comprises 8 gait tasks scored by an examiner: walking on a level surface, changing gait speed, walking during horizontal head turns, walking during vertical head turns, pivoting, stepping over an obstacle, stepping around obstacles, and waling up and down stairs. Each task is scored (0-3 points, 3 is best). Raw DGI score is the sum of the eight subtest scores and ranges from 0 to 24, with higher scores meaning better outcome and minimally important difference 3.2 points.	4 years post-implantation up to 5 years post-enrollment
PM1.2: Gain (VHITG) of the vestibulo-ocular reflex (VOR), as measured using the video head impulse test (vHIT)	During video head impulse testing (vHIT), rotational eye and head movement are measured by a goggle-mounted camera and motion sensor during brief, fast ~10 degree head rotations about the axis of a semicircular canal being tested. Performance is quantified by vestibulo-ocular reflex (VOR) gain, which a ratio of eye movement to head movement (in this case the integral of eye velocity relative to the head and the additive inverse of the integral of head velocity, respectively). VHITG, the average vHIT VOR gain for each of the three semicircular canals of the implanted ear, typically ranges from 0 to 1, with higher numbers indicating better performance.	4 years post-implantation up to 5 years post-enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
EM1.1: Vestibular Implant Composite Outcome (VICO) score	Vestibular Implant Composite Outcome (VICO) score incorporates changes in vestibulo-ocular reflex gain during video head impulse testing, postural stability, gait, dizziness handicap, and health-related quality of life at 4 years post-implantation, relative to pre-operative baseline. VICO (t=6months post-op) score is the sum of changes, from preoperative baseline to 4 years post-implantation, in vestibulo-ocular reflex gain during passive head impulse rotation (VHITG); postural stability as quantified by the Bruininks-Oseretsky Test of Motor Proficiency, 2nd Edition Balance Subtest 5 (BOT); gait stability as quantified by Dynamic Gait Index (DGI); Dizziness Handicap Inventory (DHI); and SF6D health utility (SF6DU); with each component's contribution scaled to the corresponding test's minimally important difference (MID). Score 0-100, higher scores indicate better outcomes.	4 years post-implantation up to 5 years post-enrollment
EM1.2: Bruininks-Oseretsky Test of Motor Proficiency 2nd Edition Balance Subtest 5 (BOT) score.	BOT comprises 9 postural tasks scored by an examiner: standing with both feet on a line, standing on one leg, tandem walking, walking on a line with eyes open and eyes closed, and standing on a balance beam. Each task is performed twice and scored (0-4 points, 4 is best). The BOT score is the sum of the best scores for each task. It ranges from 0 to 36 points, with higher scores meaning better outcome and minimally important difference 4.5 points.	4 years post-implantation up to 5 years post-enrollment
EM1.3: Dizziness Handicap Inventory (DHI)	Dizziness Handicap Inventory (DHI) is a 25-question survey designed to quantify self-rated disability due to dizziness and unsteadiness, with scores ranging from 0 (least disabled, best outcome) to 100 (worst outcome). The minimally important difference is 18 points.	4 years post-implantation up to 5 years post-enrollment
EM1.4: SF6D utility (SF6DU) score	SF6DU is a unitless health utility score computed from patient-reported replies to the SF6 health-related quality of life survey and ranging from 0 to 1, with higher scores meaning better outcome and minimally important difference 0.03 points.	4 years post-implantation up to 5 years post-enrollment
EM2.1: Vestibular Implant Composite Outcome (VICO) score	Vestibular Implant Composite Outcome (VICO) score incorporates changes in vestibulo-ocular reflex gain during video head impulse testing, postural stability, gait, dizziness handicap, and health-related quality of life at 4 years post-implantation, relative to pre-operative baseline. VICO (t=6months post-op) score is the sum of changes, from preoperative baseline to 4 years post-implantation, in vestibulo-ocular reflex gain during passive head impulse rotation (VHITG); postural stability as quantified by the Bruininks-Oseretsky Test of Motor Proficiency, 2nd Edition Balance Subtest 5 (BOT); gait stability as quantified by Dynamic Gait Index (DGI); Dizziness Handicap Inventory (DHI); and SF6D health utility (SF6DU); with each component's contribution scaled to the corresponding test's minimally important difference (MID). Score 0-100, higher scores indicate better outcomes.	4 years post-implantation up to 5 years post-enrollment
EM2.2: Bruininks-Oseretsky Test of Motor Proficiency 2nd Edition Balance Subtest 5 (BOT)	BOT includes 9 postural tasks scored by an examiner: standing with both feet on a line, standing on one leg, tandem walking, walking on a line with eyes open and eyes closed, and standing on a balance beam. Each task is performed twice and scored (0-4 points). The BOT score is the sum of the best scores for each task. It ranges from 0 to 36 points, with higher scores meaning better outcome and minimally important difference 4.5 points.	4 years post-implantation up to 5 years post-enrollment
EM2.3: Dizziness Handicap Inventory (DHI)	Dizziness Handicap Inventory (DHI) is a 25-question survey designed to quantify self-rated disability due to dizziness and unsteadiness, with scores ranging from 0 (least disabled, best outcome) to 100 (worst outcome). The minimally important difference is 18 points.	4 years post-implantation up to 5 years post-enrollment
EM2.4: SF6D utility (SF6DU) score	SF6DU is a unitless health utility score computed from patient-reported replies to the SF6 health-related quality of life survey and ranging from 0 to 1, with higher scores meaning better outcome and minimally important difference 0.03 points.	4 years post-implantation up to 5 years post-enrollment
EM2.5: Dynamic Gait Index (DGI)	DGI comprises 8 gait tasks scored by an examiner: walking on a level surface, changing gait speed, walking during horizontal head turns, walking during vertical head turns, pivoting, stepping over an obstacle, stepping around obstacles, and waling up and down stairs. Each task is scored (0-3 points, 3 is best). Raw DGI score is the sum of the eight subtest scores and ranges from 0 to 24, with higher scores meaning better outcome and minimally important difference 3.2 points.	4 years post-implantation up to 5 years post-enrollment
EM2.6: Gain (VHITG) of the vestibulo-ocular reflex (VOR), as measured using the video head impulse test (vHIT) and averaged for the three implanted semicircular canals	During video head impulse testing (vHIT), rotational eye and head movement are measured by a goggle-mounted camera and motion sensor during brief, fast ~10 degree head rotations about the axis of a semicircular canal being tested. Performance is quantified by vestibulo-ocular reflex (VOR) gain, which a ratio of eye movement to head movement (in this case the integral of eye velocity relative to the head and the additive inverse of the integral of head velocity, respectively). VHITG, the average vHIT VOR gain for each of the three semicircular canals of the implanted ear, typically ranges from 0 to 1, with higher numbers indicating better performance.	4 years post-implantation up to 5 years post-enrollment
EM3.1: Vestibular Implant Composite Outcome (VICO) score at 4 years post-implantation, relative to pre-operative baseline, for the subgroup of participants who have ototoxic adult-onset BVH.	Vestibular Implant Composite Outcome (VICO) score incorporates changes in vestibulo-ocular reflex gain during video head impulse testing, postural stability, gait, dizziness handicap, and health-related quality of life at 4 years post-implantation, relative to pre-operative baseline. VICO (t=6months post-op) score is the sum of changes, from preoperative baseline to 4 years post-implantation, in vestibulo-ocular reflex gain during passive head impulse rotation (VHITG); postural stability as quantified by the Bruininks-Oseretsky Test of Motor Proficiency, 2nd Edition Balance Subtest 5 (BOT); gait stability as quantified by Dynamic Gait Index (DGI); Dizziness Handicap Inventory (DHI); and SF6D health utility (SF6DU); with each component's contribution scaled to the corresponding test's minimally important difference (MID). Score 0-100, higher scores indicate better outcomes.	4 years post-implantation up to 5 years post-enrollment
EM3.2: Bruininks-Oseretsky Test of Motor Proficiency 2nd Edition Balance Subtest 5 (BOT) score 4 years post-implantation, relative to pre-operative baseline, for the subgroup of participants who have ototoxic adult-onset BVH.	BOT includes 9 postural tasks scored by an examiner: standing with both feet on a line, standing on one leg, tandem walking, walking on a line with eyes open and eyes closed, and standing on a balance beam. Each task is performed twice and scored (0-4 points). The BOT score is the sum of the best scores for each task. It ranges from 0 to 36 points, with higher scores meaning better outcome and minimally important difference 4.5 points.	4 years post-implantation up to 5 years post-enrollment
EM3.3: Dizziness Handicap Inventory (DHI) score at 4 years post-implantation, relative to pre-operative baseline, for the subgroup of participants who have ototoxic adult-onset BVH.	Dizziness Handicap Inventory (DHI) is a 25-question survey designed to quantify self-rated disability due to dizziness and unsteadiness, with scores ranging from 0 (least disabled, best outcome) to 100 (worst outcome). The minimally important difference is 18 points.	4 years post-implantation up to 5 years post-enrollment
EM3.4: SF6D utility (SF6DU) score at 4 years post-implantation, relative to pre-operative baseline, for the subgroup of participants who have ototoxic adult-onset BVH.	SF6DU is a unitless health utility score computed from patient-reported replies to the SF6 health-related quality of life survey and ranging from 0 to 1, with higher scores meaning better outcome and minimally important difference 0.03 points.	4 years post-implantation up to 5 years post-enrollment
EM3.5: Dynamic Gait Index (DGI) score at 4 years post-implantation, relative to pre-operative.baseline, for the subgroup of participants who have ototoxic adult-onset BVH.	DGI comprises 8 gait tasks scored by an examiner: walking on a level surface, changing gait speed, walking during horizontal head turns, walking during vertical head turns, pivoting, stepping over an obstacle, stepping around obstacles, and waling up and down stairs. Each task is scored (0-3 points, 3 is best). Raw DGI score is the sum of the eight subtest scores and ranges from 0 to 24, with higher scores meaning better outcome and minimally important difference 3.2 points.	4 years post-implantation up to 5 years post-enrollment
EM3.6: Gain (VHITG) of the vestibulo-ocular reflex, measured using the video head impulse test.averaged for the three implanted semicircular canals, relative to pre-operative baseline, for the subgroup of participants who have ototoxic adult-onset BVH.	During video head impulse testing (vHIT), rotational eye and head movement are measured by a goggle-mounted camera and motion sensor during brief, fast ~10 degree head rotations about the axis of a semicircular canal being tested. Performance is quantified by vestibulo-ocular reflex (VOR) gain, which a ratio of eye movement to head movement (in this case the integral of eye velocity relative to the head and the additive inverse of the integral of head velocity, respectively). VHITG, the average vHIT VOR gain for each of the three semicircular canals of the implanted ear, typically ranges from 0 to 1, with higher numbers indicating better performance.	4 years post-implantation up to 5 years post-enrollment
SM0: Type, incidence and severity of unanticipated adverse device effects as of 4 years post-implantation	Assess safety of the intervention, aggregating data across all implanted participants (diversified across ototoxic and non-ototoxic/non-central adult-onset BVH), as determined by incidence of adverse device-related events from pre-intervention to 4 years post-implantation.	4 years post-implantation up to 5 years post-enrollment
SM1.1: implant-side bone-conduction 4-frequency (0.5, 1, 2, 4 kHz) pure tone average detection threshold (BonePTAi)	BonePTAi is the 4-frequency average of pure tone detection thresholds, in dBHL, for implant-side bone-conduction presentation of pure tones at 0.5, 1, 2 and 4 kHz. Range is -10 to 80 dBHL, with change toward smaller absolute values representing better (closer to normal) outcome.	4 years post-implantation up to 5 years post-enrollment
SM1.2: implant-side air-conduction 4-frequency pure tone average detection threshold (AirPTAi)	AirPTAi is the 4-frequency average of pure tone detection thresholds, in dBHL, for implant-side air-conduction presentation of pure tones at 0.5, 1, 2 and 4 kHz. Range is -10 to 120 dBHL, with change toward smaller absolute values representing better (closer to normal) outcome.	4 years post-implantation up to 5 years post-enrollment
SM1.3: implant-side consonant-nucleus-consonant word discrimination score (CNCWi)	CNCWi is the percentage of monosyllabic consonant-nucleus-consonant words correctly repeated when presented via an earphone speaker on the implanted side in a sound-isolation booth while a masking noise is played to the contralateral ear at 40 dB above its bone-conduction 4-frequency pure tone detection threshold if that threshold is at least 10 dB better than that of the ear being tested. CNCWi ranges from 0-100% correct, with higher score meaning better outcome.	4 years post-implantation up to 5 years post-enrollment
SM1.4: sound-field Arizona Biology (AzBios)27 sentences-in-noise discrimination score	AzBios is the percentage of words correctly repeated when a set of 20 Arizona Biology sentences (randomly chosen without repeats from 15 sets) is presented at a moderate level (60 dB SPL) along with masking noise (simultaneous presentation of ten sentences from another set at aggregate sound level 55 dBSPL) to both ears via a sound field speaker in a sound-isolation booth. Scores range from 0-100% correct, with higher score meaning better outcome.	4 years post-implantation up to 5 years post-enrollment
SM1.5: Proportion of implanted ears that maintain American Academy of Otolaryngology - Head & Neck Surgery (AAO-HNS) 1995 Class A or B hearing13 or ≤ 30 dB change from preoperative baseline (if preoperative baseline is ≥20 dBHL) and ear-specific speech	For ClassABCNCW, AAO-HNS (American Academy of Otolaryngology - Head & Neck Surgery) 1995 Class A or B hearing is defined as AirPTAi not worse than 50 dBHL and CNCWi not worse than 50%. ClassABCNCW proportion ranges from 0-100%, with higher values meaning better outcomes.	4 years post-implantation up to 5 years post-enrollment
SM1.6: Proportion of implanted participants who maintain AAO-HNS 1995 Class A or B hearing or ≤ 30 dB change from preoperative baseline (if preoperative baseline is ≥20 dBHL) and ear-specific speech discrimination ≤30% worse than preoperative baseline	For ClassABAzBio, AAO-HNS (American Academy of Otolaryngology - Head & Neck Surgery) 1995 Class A or B hearing is defined as AirPTAi not worse than 50 dBHL and sound-field-presentation Arizona Biology sentences-in-noise discrimination score (AzBios) not worse than 50%. ClassABAzBio proportion ranges from 0-100%, with higher values meaning better outcomes.	4 years post-implantation up to 5 years post-enrollment
SM1.7: implant-side distortion-product otoacoustic emissions	Distortion-product otoacoustic emissions (DPOAE) are sounds generated by a normal cochlea and detectable using a microphone in the ear canal when pairs of pure tones (centered on 0.75, 1, 1.5, 2, 3, 4, 6 and 8 kHz) are presented to the ear. DPOAE signals (and 8-valued vector for responses to stimuli centered on 0.75, 1, 1.5, 2, 3, 4, 6 and 8 kHz) are quantified in dB relative to the frequency-specific noise floor recorded by the same microphone before onset of stimulation. Response range is 0-15 dB, with higher values meaning better outcome.	4 years post-implantation up to 5 years post-enrollment
SM1.8: Ear canal acoustic admittance as assessed by implant-side tympanometry	Tympanometry involves using an ear canal microphone to measure ear canal acoustic admittance (conventionally reported in units of mL) and volume (in mL) by sensing reflection of a 226 Hz tone presented via a speaker in the ear canal while ear canal pressure is slowly varied from -400 to 200 decaPascals. Negative bias pressures pull the ear drum outward, positive bias pressures push the ear drum inward, and acoustic admittance is greatest when the ear drum is in a neutral anatomic position, neither retracted inward nor ballooned outward. Results are conventionally represented graphically then summarized by a three-valued vector comprising peak compliance (range 0-2 milliliters (mL), values closer to normal range of 0.3-1.4 mL meaning more normal outcome), pressure at which compliance peaks (range -400 to 200 decaPascal, values closer to 0 meaning more normal outcome), and ear canal volume (range 0-3 mL, values closer to normal adult range of 0.6-1.4 meaning more normal outcome).	4 years post-implantation up to 5 years post-enrollment
SM1.9: Tinnitus Handicap Inventory (THI)	The Tinnitus Handicap Inventory (THI) survey is set of questions designed to quantify self-perceived handicap due to tinnitus. THI score ranges from 0-100. Higher scores mean worse outcome.	4 years post-implantation up to 5 years post-enrollment
SM1.10: Autophony Index (AI)	The Autophony Index (AI) survey is set of questions designed to quantify self-perceived autophony (hearing one's voice or other internally-generated body sounds). AI score ranges from 0-104. Higher scores mean worse outcomes.	4 years post-implantation up to 5 years post-enrollment
SM1.11: cervical vestibular-evoked myogenic potential (cVEMP) response amplitude	Cervical vestibular-evoked myogenic potentials (cVEMPs) are a measure of saccule-mediated inhibition of sternocleidomastoid muscle electromyographic (EMG) activity during presentation of loud tones to the ipsilateral ear. After normalizing to average rectified EMG activity (in microvolts) prior to sound stimulation, cVEMP amplitudes (in microvolts) are unitless. Values range from 0 to ~10, with larger values suggesting increased saccule activity and generally indicating better outcomes, except that values above 3.0 suggest abnormally high saccule sensitivity to sound.	4 years post-implantation up to 5 years post-enrollment
SM1.12: ocular vestibular-evoked myogenic potential (oVEMP) response amplitude	Ocular vestibular-evoked myogenic potentials (oVEMPs) are a measure of utricle-mediated electromyographic (EMG) activity of inferior oblique and inferior rectus extraocular muscles during presentation of loud tones to the contralateral ear. Amplitude ranges from 0 to ~50 microvolts, with larger values generally suggesting increased utricle activity and better outcomes but values above 17 microvolts suggesting abnormally high utricle sensitivity to sound.	4 years post-implantation up to 5 years post-enrollment
SM1.13: subjective visual vertical (SVV) as assessed using the Bucket Test	A participant's vision is occluded by a bucket oriented so that its axis aligns with the participant's nasooccipital axis. The examiner rotates the bucket about the axis to a new orientation, the participant reorients it until a line drawn on the floor of the bucket is judges by the participant to be Earth-vertical and deviation of that line from true vertical is recorded. Values range over -15 to 15 degrees, with smaller absolute values meaning more normal outcomes.	4 years post-implantation up to 5 years post-enrollment
SM1.14: scalp thickness at the location of implanted magnets (Tscalp)	Scalp thickness at the location of implanted magnets (Tscalp) is measured in mm using a magnetic sensor. Range is 0 to 10 mm, with values closer to the range 3-7mm indicating better outcomes.	4 years post-implantation up to 5 years post-enrollment
SM1.15: all adverse events, including but not limited to events related to the surgical procedure, device and device systems	Assess safety of the intervention, aggregating data across all implanted participants (diversified across ototoxic and non-ototoxic/non-central adult-onset BVH), as determined by changes in hearing and otolith endorgan function indicated by changes in all adverse events, including but not limited to events related to the surgical procedure, device and device systems.	4 years post-implantation up to 5 years post-enrollment
TM1: Proportion of all implanted participants who continue to use the MVI system daily at 4 years post-implantation	Assess tolerance of the intervention, aggregating data across all implanted participants, as determined by the proportion of all implant recipients who continue to use the MVI system daily at 4 years post-implantation.	4 years post-implantation up to 5 years post-enrollment
TM2: Proportion of implanted participants with non-ototoxic/non-central adult-onset BVH who continue to use the MVI system daily at 4 years post-implantation	Assess tolerance of the intervention, for the subgroup of participants who have non-ototoxic/non-central adult-onset BVH, as determined by the proportion of implanted participants with non-ototoxic/non-central adult-onset BVH who continue to use the MVI system daily at 4 years post-implantation.	4 years post-implantation up to 5 years post-enrollment
TM3: Proportion of implanted participants with ototoxic adult-onset BVH who continue to use the MVI system daily at 4 years post-implantation	Assess tolerance of the intervention, for the subgroup of participants who have ototoxic adult-onset BVH, as determined by the proportion of implanted participants with ototoxic adult-onset BVH who continue to use the MVI system daily at 4 years post-implantation.	4 years post-implantation up to 5 years post-enrollment

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
XM24.1: Number of intraoperative video recordings of electrode implantation	Deidentified video of the implantation surgery will be recorded intraoperatively. The number of participants who complete intraoperative recording will be reported.	Intraoperatively
XM24.2: Number of post-implantation temporal bone CT imagings	Deidentified images for a post-implantation temporal bone computed tomography (CT) scan will be recorded 3 weeks post-implantation. The number of participants who complete imaging will be reported.	3 weeks post-implantation
XM1.1 (A,B,C): VOR latency during VHIT	Vestibulo-ocular reflex (VOR) latency is measured in milliseconds for responses during video head impulse testing (described in 2.EM1.1) with study device providing three different modes of prosthetic vestibular nerve stimulation (A=motion-modulated/ treatment-mode stimulation, B=constant/placebo-mode stimulation, or C=no stimulation). Results are reported as a three-element vector of latencies relative to preoperative baseline (latency during mode A stimulation at 4 yr post-implantation, latency during mode B stimulation at 4 yr post-implantation, latency during mode C stimulation at 4 yr post-implantation). Latencies range from 0-1000 ms, smaller values meaning better outcome.	4 years post-implantation up to 5 years post-enrollment
XM1.2 (A,B,C): saccade latency during VHIT	Saccade (VOR) latency is measured in milliseconds for responses during video head impulse testing (described in 2.EM1.1) with study device providing three different modes of prosthetic vestibular nerve stimulation (A=motion-modulated/ treatment-mode stimulation, B=constant/placebo-mode stimulation, or C=no stimulation). Results are reported as a three-element vector of latencies relative to preoperative baseline (latency during mode A stimulation at 4 yr post-implantation, latency during mode B stimulation at 4 yr post-implantation, latency during mode C stimulation at 4 yr post-implantation). Latencies range from 0-1000 ms, smaller values meaning better outcome.	4 years post-implantation up to 5 years post-enrollment
XM2.1 (A,B,C): VOR gain-time constant product during whole-body yaw rotary chair velocity step rotations toward the implanted ear	A participant sits on a chair atop an Earth-vertical-axis rotating motor in darkness, wearing goggles that contain a camera to monitor eye rotation. The motor rotates at 240 deg/s for 1 min toward the implanted side. Slow phase nystagmus velocity is measured. Vestibulo-ocular reflex gain-time constant product GainTc is computed by multiplying gain (ratio of peak slow phase eye speed to peak chair speed) by time constant (duration after which the eye movement speed has decayed to 37% of its initial peak). GainTc ranges from 0 to 60 sec. Higher values mean better outcomes. It is measured and reported for responses during rotating chair testing with study device providing three different modes of prosthetic vestibular nerve stimulation (A=motion-modulated/ treatment-mode stimulation, B=constant/placebo-mode stimulation, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM2.2 (A,B,C): VOR frequency response during whole-body yaw rotary chair sinusoidal rotations	A participant sits on a chair atop an Earth-vertical-axis rotating motor in darkness, wearing goggles that contain a camera to monitor eye rotation. The motor rotates sinusoidally at 100 deg/s peak velocity and frequency 0.05/0.1/0.2/0.5/1 Hz. Slow phase nystagmus velocity is measured. The frequency response is a 5-element vector (one per stimulus frequency) of complex numbers, each comprising a unitless gain (eye velocity amplitude divided by chair velocity amplitude) and phase equal to 360 deg times ratio (time from peak eye velocity to peak head velocity)/(period of sinusoidal stimulus). Each gain ranges from 0 to 1; higher values mean better outcome. Each phase ranges from -180 to 180; values nearer zero mean better outcome. Frequency response is reported as a 3x5 matrix of values relative to preoperative baseline for testing with study device providing three modes of vestibular nerve stimulation: A=motion-modulated, B=constant-rate, C=off.	4 years post-implantation up to 5 years post-enrollment
XM3.1: electrically-evoked vestibulo-ocular reflex (eeVOR) response peak magnitude for largest response on each electrode	A participant sits on a motionless chair atop in darkness, wearing goggles that contain a camera to monitor eye rotation. The vestibular implant's stimulator delivers a series of electrical pulse trains to the inner via each electrode, one at a time. Slow phase nystagmus velocity is measured using the camera. For each canal, the largest measured nystagmus velocity is recorded. Velocities are reported as a 3-valued vector (the highest peak velocity measured for each of the three semicircular canals in the implanted ear), with values ranging from 0-300 deg/s and higher values meaning better outcomes.	4 years post-implantation up to 5 years post-enrollment
XM3.2: electrically-evoked vestibulo-ocular reflex (eeVOR) response 3D misalignment for largest response on each electrode	A participant sits on a motionless chair atop in darkness, wearing goggles that contain a camera to monitor eye rotation. The vestibular implant's stimulator delivers a series of electrical pulse trains to the inner via each electrode in each semicircular canal, one at a time. Slow phase nystagmus velocity is measured using the camera. For each canal, 3-dimensional (3D) misalignment (the angle in degrees between the 3D axis of peak velocity eye rotation and the 3D axis of the targeted semicircular canal) is measured for the peak nystagmus elicited by each electrode and stimulus intensity. 3D misalignment is reported as a 3-valued vector (the misalignment angles measured for each of the three semicircular canals in the implanted ear, using the electrodes and stimulus intensities that yield the largest responses approximately aligned with the target canal's axis), with values ranging from 0-180 deg and smaller values meaning better outcomes.	4 years post-implantation up to 5 years post-enrollment
XM4 (A,B,C): time to failure on Modified Romberg Test with Eyes Closed on Foam	The Modified Romberg Test with Eyes Closed on Foam involves having the participant stand for as long as possible on a foam pad with feet together, arms crossed, and eyes closed. Time to failure (i.e., moving out of position or opening the eyes) is measured for a maximum of 30 seconds for each of two attempts, and the longer of two measured durations is reported in seconds, with higher values meaning better outcomes. Values are measured with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/ treatment-mode, B=constant/placebo-mode, or C=no stimulation) and reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM5.1 (A,B,C): slope of change in treadmill dynamic visual acuity with increasing walking speed (LogMAR/mph)	A participant's visual acuity is measured while standing still and then while walking on a treadmill at 0.5, 1, 1.5, 2, 2.5 and 3 miles per hour (mph). The slope with which visual acuity (in logarithm base 10 of the minimum angle resolved, logMAR) worsens as treadmill speed increases (in mph) is measured from a line fit to the data and reported in units of (logMAR/mph), with values ranging from 0 to -1 and less negative numbers meaning better outcome. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/ treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM5.2 (A,B,C): maximum treadmill velocity achieved during (mph)	A participant's visual acuity is measured while standing still and then while walking on a treadmill at 0.5, 1, 1.5, 2, 2.5 and 3 miles per hour (mph). The highest treadmill speed the participant tolerates is recorded in mph, with higher speeds meaning better outcome. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM6.1 (A,B,C): gait speed when walking in well-light hall	A participant walks in a well-lit hall while gait speed is measured in m/s. Speeds range from 0-2 m/s, with higher values meaning better outcome. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM6.2 (A,B,C): gait speed when walking in dim light	A participant walks in dim light while gait speed is measured in m/s. Speeds range from 0-2 m/s, with higher values meaning better outcome. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM7.1 (A,B,C): TUG when walking in well-light hall	A participant performs the Timed Up and Go (TUG) test, which comprises rising from a chair, walking to and around a pylon, then returning to the chair and sitting, in a well-lit hall. Time to complete the TUG ranges over ~5-30 seconds, with lower values meaning better outcome. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM7.2 (A,B,C): TUG when walking in dim light	A participant performs the Timed Up and Go (TUG) test, which comprises rising from a chair, walking to and around a pylon, then returning to the chair and sitting, in dim light. Time to complete the TUG ranges over ~5-30 seconds, with lower values meaning better outcome. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM8.1 (A,B,C): gait speed when walking during dual task/cognitive distraction (Serial 7s downward counting)	While counting downward in increments of -7 (from a number randomly selected between 91 and 109 by the examiner), a participant walks in a well-lit hall and gait speed is measured in m/s. Speeds range from 0-2 m/s, with higher values meaning better outcome. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM8.2 (A,B,C): TUG during dual task/cognitive distraction (Serial 7s)	While counting downward in increments of -7 (from a number randomly selected between 91 and 109 by the examiner), a participant performs the Timed Up and Go (TUG) test, which comprises rising from a chair, walking to and around a pylon, then returning to the chair and sitting, in dim light. Time to complete the TUG ranges over ~5-30 seconds, with lower values meaning better outcome. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM9 (A,B,C): Serial 7s downward counting while standing with eyes open	A participant counts downward for 20 seconds in increments of -7 (from a number randomly selected between 91 and 109 by the examiner) while standing with eyes open. The number of increments correctly subtracted is counted, with higher number of increments meaning better performance. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM10.1 (A,B,C): time to complete the Trail Making Test Part B (TMT)	A participant performs the Trail Making Test Part B (TMT), using a pen to connect a set of 25 pre-drawn and numbered circles on a sheet of paper as quickly as possible while being accurate. The time in seconds required to complete the test is recorded, with shorter time meaning better performance. The test is repeated with the study device providing three different modes of prosthetic stimulation (A=motion-modulated/treatment-mode, B=constant/placebo-mode, or C=no stimulation). Results are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM10.2 (A,B,C): performance on the Triangle Completion Test (TCT)	After a practice trial with eyes open, a participant performs the Triangle Completion Test (TCT). The blindfolded participant is assisted while walking slowly along 2 segments of a pre-drawn 92.5 × 185.5 × 212 cm, 30°-60°-90° triangular path and instructed to complete the final segment independently, ending at his/her best estimate of the starting point. The participant walks counterclockwise for two triangles and then clockwise for two. End point is marked midway between each foot's largest toe. Distance (in cm, range ~0-100, smaller better) from end point to starting point and angle (absolute value, range 0-180 deg, smaller better) between the participant's path and the correct path are averaged over four trials. The test is repeated with the study device providing three modes of prosthetic stimulation: A (motion-modulated), B (constant rate) and C (off). Results are reported as a 3 by 2-valued matrix.	4 years post-implantation up to 5 years post-enrollment
XM11: electrode impedance	Electrical impedances are measured using 26.67 microsecond/phase biphasic current pulses at 302.4 cu (clinical units) of current for each of the 9 stimulating electrodes and reported as a 9-valued vector. Values range from 0 to 25 kiloohm (kΩ). Values of <2 kΩ, abnormally low and values >15 kΩ are abnormally high, values in the range 2-15 kΩ are normal, and values closer to normal range mean better outcome. Impedances for the 9 electrodes are reported as a 9-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM12: electrode location distance, as determined by post-implantation computed tomography (CT) imaging	For each canal, the distance between the center of crista ampullaris and the nearest stimulating electrode is measured on a post-implantation computed tomography (CT) scan in mm, with values ranging from 0-5 mm and smaller values meaning better outcome. Best-electrode distances for the 3 canals are reported as a 3-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM13: vestibular evoked compound action potential (veCAP)24 amplitude	Peak vestibular-evoked compound action potential (veCAP) amplitude is measured for each implanted electrode and reported for the 9 implanted electrodes, with range 0-1000 microvolts and higher values meaning better outcome, as a 9-valued vector.	4 years post-implantation up to 5 years post-enrollment
XM14.1: scalp thickness over the implant, measured on post-operative CT imaging	Scalp thickness over the implant is measured in mm using a post-operative CT scan performed 3 weeks after implantation.	4 years post-implantation up to 5 years post-enrollment
XM14.2: inductively-measured intercoil distance between implant antenna coil and external processor antenna coil	Inductively-measured intercoil distance between implant antenna coil and external processor antenna coil is measured in mm 3 weeks after implantation and 4 years post-implantation, and the change between those two values is reported in mm, with numbers less than (initial thickness minus 3 mm) meaning better outcome.	4 years post-implantation up to 5 years post-enrollment
XM15.1: Bilateral Vestibulopathy Questionnaire score (BVQ)	The Bilateral Vestibulopathy Questionnaire English version (BVQ) is a 24-question survey intended to quantify patient-reported disease burden due to bilateral vestibular hypofunction. Each question is answered on a 6-item Likert scale, with scores for positively-worded questions reversed before scoring. After averaging scores within each of 4 construct subsets, the 4 construct values are added to yield overall BVQ score, ranging from 4 to 24. Higher score means worse outcome.	4 years post-implantation up to 5 years post-enrollment
XM15.2: Number of Audio/video recording of structured interviews	Audio and video recording of a participant's responses to a structure set of questions regarding symptoms of bilateral vestibular hypofunction will be made preoperatively and at 4 years postoperatively. Responses are free-format and not quantified. The number of participants who complete video/imaging will be reported.	4 years post-implantation up to 5 years post-enrollment
XM16: Vestibular Activities of Daily Living score (VADL)	Vestibular Activities of Daily Living (VADL) is a survey designed to quantify self-rated disability due to vestibular dysfunction. Scores range from 1 (least disabled, best outcome) to 10 (worst outcome) points.	4 years post-implantation up to 5 years post-enrollment
XM17 (A,B,C): Oscillopsia Visual Analog Scale score (oVAS)	The Oscillopsia Visual Analog Scale (oVAS) is a 43-question survey designed to quantify self-rated oscillopsia. Each item is answered on a 6-point Likert scale (integer scores of 0 to 5, with the score X for each negatively phrase questions transformed to 5-X before summation across all questions). Total score ranges from 0 (least oscillopsia, best outcome) to 215 (worst outcome) points.	4 years post-implantation up to 5 years post-enrollment
XM18: Activities-specific Balance Confidence Scale score (ABC)	The Activities-specific Balance Confidence Scale (ABC) is a 16-question survey designed to quantify self-rated confidence performing daily activities that require balance. Each item is answered on an 11-item Likert scale (from 0 to 100% confidence, in 10% increments). Total score is the average of the 16 responses and ranges from 0 (least confident, worst outcome) to 100% (most confident, best outcome).	4 years post-implantation up to 5 years post-enrollment
XM19.1: Vertigo Symptom Scale score (VSS)	The vertigo-balance subscale score of the Vertigo Symptom Scale is a 15-item survey designed to quantify self-rated vertigo symptom severity. Each item is answered on a 5-item Likert scale (from 0 to 4, higher meaning more frequent/worse symptoms). Total score is the sum of the 15 responses and ranges from 0 (least severe/frequent, best outcome) to 75 (worst outcome).	4 years post-implantation up to 5 years post-enrollment
XM19.2: Vertigo Visual Analogue Scale score (VAS)	The Vertigo Visual Analogue Scale is a 9-item visual analogue scale designed to assess the intensity of vertigo symptoms for patients in different daily situations that typically induce visual vertigo. Each item is answered on a visual analogue scale by drawing a vertical line on a 10 cm line between two anchors marked 0 and 10 (with zero (0) representing no dizziness and ten (10) representing most dizziness). Total score is the sum of the 9 responses, divided by the number of answered items, and multiplied by 10. (ranges from 0 (least severe, best outcome) to 100 (most severe, worst outcome).	4 years post-implantation up to 5 years post-enrollment
XM20.1: Health Utilities Index Mark 3 (HUI)	The Health Utilities Index Mark 3 is an instrument designed to measure health status and health-related quality of life. HUI Mark 3 provides a utility score ranging from 0 (worst outcome) to 1 (best outcome).	4 years post-implantation up to 5 years post-enrollment
XM20.2: EuroQol 5 Dimension (EQ-5D)	The EuroQOL EQ5D is a 5-dimension (mobility, self-care, usual activities, pain/discomfort, anxiety depression) instrument developed to evaluate health-related quality of life. Each of the five dimensions includes five levels of severity going from 1-5 (no problems (1), slight problems (2), moderate problems (3), severe problems (4), unable to/extreme problems (5)). Scores for each dimension are combined to obtain a total score in the form of a 5 digit code (Greater number of higher scores means worse outcome.)	4 years post-implantation up to 5 years post-enrollment
XM21: Tinnitus Handicap Inventory (THI)	The Tinnitus Handicap Inventory (THI) survey is set of questions designed to quantify self-perceived handicap due to tinnitus. THI score ranges from 0-100. Higher scores mean worse outcome.	4 years post-implantation up to 5 years post-enrollment
XM22: Autophony Index (AI)	The Autophony Index (AI) survey is set of questions designed to quantify self-perceived autophony (hearing one's voice or other internally-generated body sounds). AI score ranges from 0-104. Higher scores mean worse outcomes.	4 years post-implantation up to 5 years post-enrollment
XM23.1: OTOSCOPE genetic testing panel (or equivalent panel from another Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory, such as Invitae Corpl) for participants who agree to genetic testing	For participants with a history of nonototoxic bilateral vestibular hypofunction who agree to clinical genetic testing, a University of Iowa Molecular Otology Research Laboratory OtoSCOPE® Genetic Hearing Loss Testing v9 test will be performed on a buccal swab to determine the presence or absence of an identifiably inner ear gene abnormality, and the deidentified result will be reported.	Preoperative baseline
XM23.2: Presence or absence of Mitochondrially Encoded 12S RRNA (MTRNR1) gene abnormality as assessed by genetic test panel (or equivalent) for participants with known ototoxic exposure who agree to genetic testing	For participants with a history of ototoxic bilateral vestibular hypofunction who agree to clinical genetic testing, an MTRNR1 genetic testing panel screen will be completed to determine the presence or absence of an MTRNR1 gene abnormality, and the deidentified result will be reported.	Preoperative baseline
XM23.3: RFC1 presence or absence of an MTRNR1 gene abnormality as assessed by Ataxia/CANVAS genetic testing panel (or equivalent) for participants suspected to have CANVAS or demonstrate potential CANVAS related symptoms	For participants with a history of ototoxic bilateral vestibular hypofunction who agree to clinical genetic testing, an MTRNR1 genetic testing panel screen will be completed to determine the presence or absence of an MTRNR1 gene abnormality, and the deidentified result will be reported.	Preoperative baseline
XM25: Study visit duration (days) by activity/test/assessment	Explore ways to improve efficiency of procedures for performance assessment and stimulus parameter adjustment by measuring change in study visit duration by activity/test/assessment.	4 years post-implantation up to 3 years post-enrollment
XM26: Number of audio/video recording of participants' descriptions of motion percepts during eeVOR testing	Deidentified audio/video of the of participants' descriptions of motion percepts during eeVOR testing. The number of participants who complete video/recording will be reported.	4 years post-implantation up to 3 years post-enrollment

Collaborators and Investigators

• Sponsor: Johns Hopkins University
• Collaborators: National Institute on Aging (NIA); National Institute on Deafness and Other Communication Disorders (NIDCD); Labyrinth Devices, LLC
• Investigators: Principal Investigator: John P Carey, MD, Johns Hopkins School of Medicine

Publications and helpful links

General Publications

• Sun DQ, Lehar M, Dai C, Swarthout L, Lauer AM, Carey JP, Mitchell DE, Cullen KE, Della Santina CC. Histopathologic Changes of the Inner ear in Rhesus Monkeys After Intratympanic Gentamicin Injection and Vestibular Prosthesis Electrode Array Implantation. J Assoc Res Otolaryngol. 2015 Jun;16(3):373-87. doi: 10.1007/s10162-015-0515-y. Epub 2015 Mar 20.
• Sun DQ, Ward BK, Semenov YR, Carey JP, Della Santina CC. Bilateral Vestibular Deficiency: Quality of Life and Economic Implications. JAMA Otolaryngol Head Neck Surg. 2014 Jun;140(6):527-34. doi: 10.1001/jamaoto.2014.490.
• Mitchell DE, Dai C, Rahman MA, Ahn JH, Della Santina CC, Cullen KE. Head movements evoked in alert rhesus monkey by vestibular prosthesis stimulation: implications for postural and gaze stabilization. PLoS One. 2013 Oct 17;8(10):e78767. doi: 10.1371/journal.pone.0078767. eCollection 2013.
• Dai C, Fridman GY, Chiang B, Rahman MA, Ahn JH, Davidovics NS, Della Santina CC. Directional plasticity rapidly improves 3D vestibulo-ocular reflex alignment in monkeys using a multichannel vestibular prosthesis. J Assoc Res Otolaryngol. 2013 Dec;14(6):863-77. doi: 10.1007/s10162-013-0413-0. Epub 2013 Sep 8.
• Ward BK, Agrawal Y, Hoffman HJ, Carey JP, Della Santina CC. Prevalence and impact of bilateral vestibular hypofunction: results from the 2008 US National Health Interview Survey. JAMA Otolaryngol Head Neck Surg. 2013 Aug 1;139(8):803-10. doi: 10.1001/jamaoto.2013.3913.
• Valentin NS, Hageman KN, Dai C, Della Santina CC, Fridman GY. Development of a multichannel vestibular prosthesis prototype by modification of a commercially available cochlear implant. IEEE Trans Neural Syst Rehabil Eng. 2013 Sep;21(5):830-9. doi: 10.1109/TNSRE.2013.2259261. Epub 2013 May 1.
• Davidovics NS, Rahman MA, Dai C, Ahn J, Fridman GY, Della Santina CC. Multichannel vestibular prosthesis employing modulation of pulse rate and current with alignment precompensation elicits improved VOR performance in monkeys. J Assoc Res Otolaryngol. 2013 Apr;14(2):233-48. doi: 10.1007/s10162-013-0370-7. Epub 2013 Jan 26.
• Fridman GY, Della Santina CC. Progress toward development of a multichannel vestibular prosthesis for treatment of bilateral vestibular deficiency. Anat Rec (Hoboken). 2012 Nov;295(11):2010-29. doi: 10.1002/ar.22581. Epub 2012 Oct 8.
• Rahman MA, Dai C, Fridman GY, Davidovics NS, Chiang B, Ahn J, Hayden R, Melvin TA, Sun DQ, Hedjoudje A, Della Santina CC. Restoring the 3D vestibulo-ocular reflex via electrical stimulation: the Johns Hopkins multichannel vestibular prosthesis project. Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:3142-5. doi: 10.1109/IEMBS.2011.6090857.
• Dai C, Fridman GY, Davidovics NS, Chiang B, Ahn JH, Della Santina CC. Restoration of 3D vestibular sensation in rhesus monkeys using a multichannel vestibular prosthesis. Hear Res. 2011 Nov;281(1-2):74-83. doi: 10.1016/j.heares.2011.08.008. Epub 2011 Aug 26.
• Dai C, Fridman GY, Chiang B, Davidovics NS, Melvin TA, Cullen KE, Della Santina CC. Cross-axis adaptation improves 3D vestibulo-ocular reflex alignment during chronic stimulation via a head-mounted multichannel vestibular prosthesis. Exp Brain Res. 2011 May;210(3-4):595-606. doi: 10.1007/s00221-011-2591-5. Epub 2011 Mar 4.
• Dai C, Fridman GY, Della Santina CC. Effects of vestibular prosthesis electrode implantation and stimulation on hearing in rhesus monkeys. Hear Res. 2011 Jul;277(1-2):204-10. doi: 10.1016/j.heares.2010.12.021. Epub 2010 Dec 31.
• Della Santina CC. Regaining balance with bionic ears. Sci Am. 2010 Apr;302(4):68-71. doi: 10.1038/scientificamerican0410-68. No abstract available.
• Fridman GY, Davidovics NS, Dai C, Migliaccio AA, Della Santina CC. Vestibulo-ocular reflex responses to a multichannel vestibular prosthesis incorporating a 3D coordinate transformation for correction of misalignment. J Assoc Res Otolaryngol. 2010 Sep;11(3):367-81. doi: 10.1007/s10162-010-0208-5. Epub 2010 Feb 23.
• Della Santina CC, Migliaccio AA, Patel AH. A multichannel semicircular canal neural prosthesis using electrical stimulation to restore 3-d vestibular sensation. IEEE Trans Biomed Eng. 2007 Jun;54(6 Pt 1):1016-30. doi: 10.1109/TBME.2007.894629.
• Hedjoudje A, Schoo DP, Ward BK, Carey JP, Della Santina CC, Pearl M. Vestibular Implant Imaging. AJNR Am J Neuroradiol. 2021 Jan;42(2):370-376. doi: 10.3174/ajnr.A6991. Epub 2020 Dec 24.
• Chow MR, Ayiotis AI, Schoo DP, Gimmon Y, Lane KE, Morris BJ, Rahman MA, Valentin NS, Boutros PJ, Bowditch SP, Ward BK, Sun DQ, Trevino Guajardo C, Schubert MC, Carey JP, Della Santina CC. Posture, Gait, Quality of Life, and Hearing with a Vestibular Implant. N Engl J Med. 2021 Feb 11;384(6):521-532. doi: 10.1056/NEJMoa2020457.
• Boutros PJ, Schoo DP, Rahman M, Valentin NS, Chow MR, Ayiotis AI, Morris BJ, Hofner A, Rascon AM, Marx A, Deas R, Fridman GY, Davidovics NS, Ward BK, Trevino C, Bowditch SP, Roberts DC, Lane KE, Gimmon Y, Schubert MC, Carey JP, Jaeger A, Della Santina CC. Continuous vestibular implant stimulation partially restores eye-stabilizing reflexes. JCI Insight. 2019 Nov 14;4(22):e128397. doi: 10.1172/jci.insight.128397.

Helpful Links

• Trial-related news updates and links to application

Study record dates

Study Major Dates

• Study Start (Actual): December 1, 2024
• Primary Completion (Estimated): December 1, 2029
• Study Completion (Estimated): December 1, 2029

Study Registration Dates

• First Submitted: July 8, 2024
• First Submitted That Met QC Criteria: July 8, 2024
• First Posted (Actual): July 15, 2024

Study Record Updates

• Last Update Posted (Actual): March 9, 2026
• Last Update Submitted That Met QC Criteria: March 5, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Prosthesis; Dizziness; Implant; Ototoxicity; Vestibular; Gentamicin; Inner Ear; Disequilibrium; Labyrinth; Oscillopsia; Vestibulopathy
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Wounds and Injuries; Pathologic Processes; Chemically-Induced Disorders; Otorhinolaryngologic Diseases; Ear Diseases; Drug-Related Side Effects and Adverse Reactions; Radiation Injuries; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Ototoxicity; Bilateral Vestibulopathy; Vestibular Diseases; Labyrinth Diseases; Sensation Disorders; Dizziness; Dysequilibrium syndrome
• Other Study ID Numbers: IRB00434328

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Publication of de-identified data via peer-reviewed journals.
• IPD Sharing Time Frame: Beginning 6 months after publication and ending 36 months after publication.
• IPD Sharing Access Criteria: Data will be shared with researchers who provide a methodologically sound proposal and signed data access agreement. Proposals should be directed to vestibularimplant@jhmi.edu.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes