Long Term Outcomes After Vestibular Implantation

Overview

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.

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) .

Interventions

• 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)

Primary outcome measures

• 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. [Time frame: 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) [Time frame: 4 years post-implantation up to 5 years post-enrollment]

Secondary outcome measures (12)

• EM1.1: Vestibular Implant Composite Outcome (VICO) score [Time frame: 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. [Time frame: 4 years post-implantation up to 5 years post-enrollment]
• EM1.3: Dizziness Handicap Inventory (DHI) [Time frame: 4 years post-implantation up to 5 years post-enrollment]
• EM1.4: SF6D utility (SF6DU) score [Time frame: 4 years post-implantation up to 5 years post-enrollment]
• EM2.1: Vestibular Implant Composite Outcome (VICO) score [Time frame: 4 years post-implantation up to 5 years post-enrollment]
• EM2.2: Bruininks-Oseretsky Test of Motor Proficiency 2nd Edition Balance Subtest 5 (BOT) [Time frame: 4 years post-implantation up to 5 years post-enrollment]
• EM2.3: Dizziness Handicap Inventory (DHI) [Time frame: 4 years post-implantation up to 5 years post-enrollment]
• EM2.4: SF6D utility (SF6DU) score [Time frame: 4 years post-implantation up to 5 years post-enrollment]
• EM2.5: Dynamic Gait Index (DGI) [Time frame: 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 [Time frame: 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. [Time frame: 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. [Time frame: 4 years post-implantation up to 5 years post-enrollment]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

United States · 1 center

• Johns Hopkins School of Medicine — Baltimore

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. PMID 25790951
• 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. PMID 24763518
• 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. PMID 24147142
• 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. PMID 24013822
• 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. PMID 23949355
• 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. PMID 23649285
• 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. PMID 23355001
• 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. PMID 23044664

Identifiers

NCT: NCT06500975 · IRB00434328

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗