Iowa Cochlear Implant Clinical Research Center Hybrid L24 and Standard Cochlear Implants in Profoundly Deaf Infants
Condition: Implants, Cochlear; Child; Hearing Loss, Bilateral
MeSH terms: Hearing Loss; Hearing Loss, Bilateral
Study type: Interventional

Summary: 
      The purpose of this feasibility study is to evaluate whether implantation of one Nucleus L24
      electrode array and one FDA approved standard-length device in the contralateral ear can
      provide useful binaural hearing in pediatric subjects who have bilateral severe to profound
      hearing loss, meeting the criteria for cochlear implantation. Unlike a conventional cochlear
      implant, the Nucleus L24 is expected to preserve the regions of the cochlear partition that
      are apical to the electrode, thus leaving them available for possible future advances in the
      field of otolaryngology and hearing devices, such as mammalian hair cell regeneration
      techniques or improved implantable hearing devices. Whether or not this group of children
      will be able to take advantage of future hair cell regeneration strategies is yet to be
      determined and will have to wait for future development. At this time there are no accurate
      imaging strategies available to identify preservation of the scala media. Ultra thin micro CT
      scanning is in development, however the level of radiation delivery to the subject is too
      great to be considered for clinical use. When imaging strategies become available to
      determine cellular structure of the inner ear, they will be applied to this group of
      subjects. The Nucleus L24 array stimulates the basal turn of the cochlea, in an attempt to
      preserve the middle and apical regions of the scala media.
    

Detailed description: 
      The purpose of this feasibility study is to evaluate whether a Nucleus L24 and a FDA approved
      standard-length device in the contralateral ear can provide useful binaural hearing in
      pediatric subjects who have bilateral profound hearing loss, meeting the criteria for
      cochlear implantation. Unlike a conventional cochlear implant, the Nucleus L24 is designed to
      preserve the regions of the cochlear partition that are apical to the electrode, thus leaving
      them available for possible future advances in the field of otolaryngology and hearing
      devices, such as mammalian hair cell regeneration techniques or improved implantable hearing
      devices. The Nucleus L24 (16 mm) array stimulates the basal turn of the cochlea, in an
      attempt to preserve the middle and apical regions of the scala media.

      The study will be conducted as a repeated-measure, single-subject experiment. A
      single-subject research design (in which each participant serves as his or her own control)
      is appropriate because it accommodates the heterogeneity that characterizes hearing-impaired
      populations. Blinding or masking procedures are not included in the design, as it is not
      possible to conceal the presence or absence of a cochlear implant from device recipients
      and/or clinical investigators.

      Preoperatively, candidates will be assessed with their current amplification to evaluate
      their appropriateness for entrance into the study. The candidates' audiometric configuration
      must meet the above inclusion criteria. That is, the candidate must have a profound
      sensorineural hearing loss from 250 to 8000 Hz. Prior to testing, the appropriateness of the
      hearing aid fitting will be assessed and adjustments made if necessary. In cases where
      amplification has not been used for more than one year, new hearing aids will be fit, worn
      for a minimum three-month trial and the participants re-evaluated to confirm continuance with
      the study.

      Fifteen infants will receive one Nucleus L24 array and a FDA approved standard-length array
      on contralateral ears. The investigator will alternate every other subject between the right
      and left ears as to which ear gets the Nucleus L24. Postoperatively, the right ear only, left
      ear only, and the bilateral listening modes will be compared with repeated testing through
      five years of age of the child. These comparisons will help to evaluate the effects of
      bilateral stimulation using a shorter electrode cochlear implant to possibly preserve the
      scala media, organ of Corti, and supporting cells for future medical interventions and a
      standard length implant on the contralateral ear. In addition, the investigator will attempt
      to compare speech perception and speech/language measure results with age-matched children
      implanted with standard-length bilateral devices.
    

Intervention name(s): Hybrid L24
Intervention type(s): Device
Intervention description(s): Fifteen infants will receive one Nucleus L24 array and a FDA approved standard-length array on contralateral ears.
Intervention model: Single Group Assignment
Intervention model description: repeated-measure, single-subject experiment
Masking: None (Open Label)
Primary purpose: Treatment