Multichannel Vestibular Implant Early Feasibility Study

The system used in this study is the (MVI)™ Multichannel Vestibular Implant System produced
by Labyrinth Devices, LLC. It is similar to commercially available cochlear implants in that
it includes an implanted stimulator powered and controlled by an external unit, which
communicate with the implant across the skin via an inductive link. Unlike a cochlear
implant, the implanted stimulator's electrode array is designed for implantation near the
ends of the vestibular nerve. The implanted stimulator also includes additional magnets to
help facilitate retention of the external unit on the scalp over the implant. The external
unit includes a head-worn unit (for sensing head motion and delivering power and signals to
the implanted stimulator) and a power and control unit containing a battery and
microprocessor. Participants in this trial who meet candidacy criteria and who choose to
proceed with implantation surgery, device activation and device deactivation will be asked to
participate in a series of post-operative monitoring visits over a 1 year period.

Inclusion Criteria:

- Adults age 22.0-90 with bilateral vestibular deficiency not responsive to vestibular
rehabilitation as determined by pre-inclusion history, vestibular testing and clinical
examination

- Hearing status: (1) Hearing in the candidate ear for implantation is equivalent to or
worse than that in the contralateral ear; and (2) hearing in the contralateral ear is
good enough to allow functional communication in case hearing in the implanted ear is
lost after implantation. Specifically, the contralateral ear must satisfy all of the
following criteria:

1. 0.5/1/2/4 kilohertz (kHz) pure-tone-average threshold (PTA) hearing better than
(i.e., less than) 70 dB hearing loss (HL); and

2. ear-specific sentence recognition score using the recorded AzBio Sentence Test
presented at 60 dB sound pressure level A (SPL-A) in quiet must be >60% when
tested under either the unaided condition or, if 0.5/1/2/4 kHz PTA>50 dB, the
best-aided condition; and

3. ear-specific word recognition score using the recorded
Consonant-Nucleus-Consonant (CNC) Word Recognition Test presented at 60 decibels
hearing level (dB HL) in quiet must be >60% when tested under either the unaided
condition or, if 0.5/1/2/4 kHz PTA>50 dB, the best-aided condition

- Caloric responses consistent with severe or profound bilateral loss of labyrinthine
function (total caloric response to warm and cool caloric stimuli <10°/sec in each
ear; lack of a reversal of response on ice-water caloric stimulation when subject
reorients from supine to prone)

- Prior MRI imaging of the brain, internal auditory canals and cerebellopontine (CP)
angle showing a patent labyrinth, present vestibular nerve, patent cochlea, present
cochlear nerve, and absence of internal auditory canal/cerebellopontine angle tumors
or other central causes of vestibulo-ocular reflex dysfunction or sensorineural
hearing loss

- Prior CT imaging of the temporal bones showing a facial nerve canal with normal
caliber and course, middle ear without evidence of chronic otitis media or tympani
membrane perforation or cholesteatoma, a mastoid cavity with adequate aeration for
surgical access to each semicircular canal, skull thickness ≥3 mm at the planned well
site, and scalp soft tissue thickness ≤7 mm. This criterion may be satisfied without
additional imaging if an existing head CT or MRI already demonstrates those findings

- Vaccinations as recommended per Johns Hopkins Listening Center protocols to reduce the
risk of meningitis in subjects undergoing cochlear implantation, as described at this
site:
http://www.hopkinsmedicine.org/otolaryngology/specialty_areas/listencenter/vaccine.htm
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- Motivated to travel to the study center, to undergo testing and examinations required
for the investigational study, and to participate actively in a vestibular
rehabilitation exercise regimen

- The participant must agree not to swim or to use or operate vehicles, heavy machinery,
powered tools or other devices that could pose a threat to the participant, to others,
or to property throughout the duration of participation in the study and until at
least 1 month after final deactivation of the MVI Implant

Exclusion Criteria:

- Inability to understand the procedures and the potential risks involved as determined
by study staff

- Inability to participate in study procedures due to blindness, ≤ ±10° neck range of
motion, cervical spine instability, ear canal stenosis or malformation sufficient to
prevent caloric testing

- Diagnosis of acoustic neuroma/vestibular schwannoma, chronic middle ear disease,
cholesteatoma, or central nervous system causes of vestibulo-ocular reflex
dysfunction, including chronic and continuing use of medications, drugs or alcohol at
doses sufficiently great to interfere with vestibular compensation

- Vestibular dysfunction known to be caused by reasons other than labyrinthine injury
due to ototoxicity, ischemia, trauma, infection, Meniere's disease, or genetic defects
known to act on hair cells

- Lack of labyrinth patency or vestibular nerve as determined by MRI of the brain with
attention to the internal acoustic meatus

- Any contraindication to the planned surgery, anesthesia, device activation and
deactivation, or participation in study assessments, as determined by the surgeon,
anesthesiologist, or designee, including known intolerance of any materials used in
any component of the investigational devices that will come in contact with the
subject

- History of myocardial infarction, coronary bypass surgery, or any percutaneous
coronary intervention within 6 months prior to screening

- Subjects with estimated glomerular filtration rate (GFR) < 30 ml/min at screening

- Subjects with heart failure New York Heart Association (NYHA) class III or IV

- Subjects with Child-Pugh class C cirrhosis

- A psychiatric disease or substance abuse history likely to interfere with protocol
compliance

- Contraindications to scleral coil eye movement testing, including monocular blindness
and a history of fainting vagal reactions to prior eye manipulations would exclude
subjects from eye coil testing

- Inability to tolerate baseline testing protocols

- Recent corneal injury

- A history of cervical spine disease preventing head rotation

- A history of fainting or vagal reactions prior to eye manipulations that would
preclude 3D eye movement coil testing

- Pregnancy, positive urine or serum pregnancy test at any time during study
participation,

- Ability to become pregnant combined with failure or refusal to consistently use a
highly effective method of contraception from at least 1 month prior to implantation
to not before 1 month after both device deactivation and conclusion of study
participation.

- Women who are nursing/lactating

- Any medical condition, judged by the investigator team, that is likely to interfere
with a study candidate's participation in the study or likely to cause serious adverse
events during the study.