Adult Non-Neurofibromatosis Type 2 (NF2) Subjects


Study of the Nucleus 24 Auditory Brainstem Implant in Adult Non-Neurofibromatosis Type 2 Subjects

MEEI Protocol ID


National Clinical Trial (NCT) Number



Sensorineural Hearing Loss
Bilateral Deafness


Daniel Lee, M.D.

Principal Investigator

Daniel Lee, M.D.

Study Design

Endpoint Classification: Safety Study
Intervention Model: Single Group Assignment
Masking: Open LabelPrimary Purpose: Treatment

Study Objective

The purpose of this research study is to determine whether Auditory Brainstem Implant (ABI) can improve hearing in persons who are deaf in both ears, do not have Neurofibromatosis Type 2 (NF2), and are not candidates for cochlear implants.

Who is Eligible

Adult patients (>=18 years of age) with cochlear or retrocochlear conditions that interfere with transmission of auditory information from the cochleae to the brain on both sides, resulting in severe to profound post-lingual bilateral deafness. All subjects will undergo bone conduction threshold audiometry to confirm sensorineural hearing loss and rule out potential middle ear disorders.

Candidates for this clinical trial will have post-lingual deafness that cannot be otherwise managed with conventional hearing aids or cochlear implants (CI). If CI were previously used, subjects will have had a failed response, defined as ≤ 30% speech recognition and patient perception of inadequate benefit to continue using the device.

Candidates for this clinical trial will have one or more of these conditions:

  • Bilateral severe/completely ossified cochleae
  • Bilateral severe inner ear malformations leading to poor CI outcomes
  • Bilateral temporal bone fractures, where the VIIIth cranial nerves have been disrupted
  • Bilateral cochlear nerve agenesis
  • Not otherwise a cochlear implant candidate based on above listed pathology, intolerable adverse effects with CI (e.g. stimulation of the facial nerve), or Evoked Auditory Potential testing predictive of a poor response, or auditory neuropathy or auditory dyssynchrony and failed CI surgery)
  • Any combination of the conditions listed above

Subject Enrollment

10 Adults

Study Procedures

Screening Procedures:
After confirming that potential study participants meet basic demographic inclusion criteria, patients will be evaluated by the principal investigator, Daniel Lee MD, a board-certified neurotologic surgeon at MEEI. A detailed history will be obtained and physical exam will be completed. Subjects will also be evaluated for baseline qualitative measures using questionnaires and quantitative measures using audiologic testing. In particular, audiometric threshold testing will be completed to confirm acoustic baseline auditory function. These parameters will be compared to inclusion criteria to determine if a subject meets all inclusion criteria and represents a viable candidate for ABI surgery.

Enrollment/Baseline Procedures:
All baseline procedures will be completed at the time of screening. This includes qualitative measurement using the Modified Hearing Handicap Inventory, Dizziness Handicap Inventory, and Quality of Life (SF-36) questionnaires as well as audiologic tests such as standard audiometric threshold testing.

Study Drug or Device Procedures:
Subjects will undergo pre-operative evaluation for ABI surgery. Those subjects that are appropriate for surgery will undergo a procedure for implantation of the Cochlear Corporation ABI24 system. As per manufacturer protocol, the parameters of the ABI24 system including adjustment of electrode sensitivities and activation of specific electrodes will be completed at each follow-up visit post-operatively. This process involves adjustment of device parameters by a trained audiologist who subsequently administers audiologic tests to confirm optimal activation of the ABI24 device.

Standard of Care Procedures:
All audiologic testing and assessments represent the standard of care. Aspects of our study that go beyond routine standard of care are outlined above and in the informed consent.

Follow-up Procedures:
Study participants will have audiologic testing and device activation and adjustment completed at follow-up appointments. These post-operative follow-up appointments will occur at 4-12 weeks, three, six, and twelve months, and biannually thereafter until the study end point of five years. Timing of these appointments may vary by as much as four weeks prior to or after the planned follow-up date (e.g. between 2-4 months for the 3 month follow-up).

For More Information

617-573-3130 or

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Page updated 12/21/2016.