Hybrid Cochlear Implants in Severe to Profound Adults, Children, and Adolescents

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to determine if adults and children with residual low-pitch hearing in the severe hearing loss range can develop improved speech perception by combining their residual acoustic hearing with electrical stimulation through a short cochlear implant. The low-pitches would be amplified with a hearing aid and the high-pitch sounds would be stimulated electrically.

Detailed Description
-----------------
The purpose of this study is to determine if individuals with residual low-frequency hearing in the severe range can develop improved speech perception by combining their residual acoustic hearing with electrical processing through a cochlear implant designed to stimulate the high-frequency basal and middle turn of the cochlea while preserving useful low-frequency acoustic hearing. To accomplish this, we propose to implant individuals with severe hearing with a Cochlear® Nucleus™ Hybrid L24 Implant or a Cochlear® Nucleus™ Hybrid S12 in the poorer ear. We believe these devices will do less damage to the Organ of Corti structures, than longer, more invasive standard cochlear implant electrodes. Two different populations will be studied under this IDE. Population 1: 15 Adults who have a severe sensorineural hearing loss with a pure-tone average (PTA) between 60-90 decibels (dB) hearing level (HL) between 125-1500 Hz and profound loss at higher frequencies will be implanted with the Cochlear® Nucleus™ Hybrid L24 Implant. The potential subject will present with Consonant-Nucleus-Consonant (CNC) monosyllabic word scores between 0-35% in the ear to be implanted and up to 60% understanding in the contralateral ear in the best-aided condition. Population 2: 30 Children (ages 5-12 years) and adolescents (ages 13-15 years) who have a sensorineural hearing loss with a pure-tone average (PTA) between 60-90 dB HL between 125-1500 Hz and profound loss at higher frequencies will be implanted with the Cochlear® Nucleus™ Hybrid L24 Implant or the Cochlear® Nucleus™ Hybrid S12 Implant. Those that have hearing thresholds between 60-90 dB HL at 1500 Hz would be implanted with the less invasive shorter 10 mm Hybrid S12 in attempt to better preserve the middle frequency range. Those with hearing thresholds >90 dB HL at 1500 Hz would receive the longer 16 mm Hybrid L24 electrode. The potential subject will present with Phonetically Balanced Kindergarten (PB-K) monosyllabic word scores between 0-50% in the ear to be implanted and up to 60% understanding in the contralateral ear in the best-aided condition. Through the preserved acoustic hearing, we believe the subject will experience better signal to noise ratios for speech perception in noise, better localization of sound and an improvement music perception. Histological evidence from patients implanted with standard arrays and our experience with a short electrode array for implantation of individuals with significant residual hearing both support this assumption (Nadol, Shiao, Burgess, Ketten, Eddington et al., 2001). The duration of this study will be 2 years (24 months) for adults and for 5 years (60 months) in children and adolescents.

Official Title
-----------------
Iowa Cochlear Implant Clinical Research Center Hybrid Cochlear Implants in Severe to Profound Adults, Children, and Adolescents

Conditions
-----------------
Hearing Loss, High-Frequency

Intervention / Treatment
-----------------
* Device: Cochlear® Nucleus™ Hybrid L24
* Device: Cochlear® Nucleus™ Hybrid S12


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: 1.1 Criteria for Inclusion in Population 1 Criterion for selection will be subject interest in preservation of residual hearing; severe sensorineural hearing loss; lack of benefit from appropriately fit binaural hearing aids worn on a full-time basis; and realistic expectations. Qualified participants must also meet the following criteria for inclusion: Eighteen year of age or older at the time of implantation. Severe sensorineural hearing loss with a pure-tone average (PTA) between 60-90 dB HL between 125-1500 Hz and profound loss at higher frequencies in the ear to be implanted. Speech Perception: The Consonant-Nucleus-Consonant (CNC) word recognition score between 0% and 35% inclusive in the ear to be implanted. The CNC word recognition score in the contralateral ear equal to or better than, in the ear to be implanted but not more than 60% in the best-aided condition. English spoken as a primary language. Willingness to comply with all study requirements. Minimum of 30 day hearing aid trial with appropriately fit hearing aids worn on a full-time basis (8 hours per day). Patent cochlea and normal cochlear anatomy. 1.2 Criteria for Inclusion in Population 2 Criterion for selection will be parent interest in preservation of residual hearing; severe post-lingual onset of sensorineural hearing loss; lack of benefit from appropriately fit binaural hearing aids worn on a full-time basis; and supportive family dynamics. Qualified participants must also meet the following criteria for inclusion: Five to fifteen years of age at the time of implantation. Severe sensorineural hearing loss with a pure-tone average (PTA) between 60-90 dB HL between 125-1500 Hz and profound loss at higher frequencies in the ear to be implanted. Speech Perception: The Phonetically Balanced-Kindergarten (PB-K) word recognition score between 0% and 50% inclusive in the ear to be implanted. The PB-K word recognition score in the contralateral ear equal to or better than, in the ear to be implanted but not more than 60%. English spoken as a primary language. Willingness to comply with all study requirements. Minimum of 30-day hearing aid trial with appropriately fit hearing aids worn on a full-time basis (8 hours per day).. Patent cochlea and normal cochlear anatomy. Must be in a habilitation/educational program with an emphasis on spoken language development. Exclusion Criteria: 1.3 Criteria for Exclusion in Populations 1 and 2 Medical or psychological conditions that contraindicate undergoing surgery. Ossification or any other cochlear anomaly that might prevent complete insertion of the electrode array. Unrealistic expectations on the part of the candidate and/or candidate's family, regarding the possible benefits, risks, and limitations that are inherent to the surgical procedure(s) and prosthetic devices. Unwillingness or inability of the candidate to comply with all investigational requirements. Active middle ear infection.

Ages Eligible for Study
-----------------
Minimum Age: 5 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Adult<br>Population 1: 15 Adults who have a severe sensorineural hearing loss with a pure-tone average (PTA) between 60-90 dB HL between 125-1500 Hz and profound loss at higher frequencies. Intervention: These patients will receive a Hybrid L24 cochlear implant. | Device: Cochlear® Nucleus™ Hybrid L24<br>* The Nucleus Hybrid L24 cochlear implant incorporates an electrode array designed to preserve residual hearing. This has been accomplished by employing a thin, straight, intracochlear electrode array attached to a Nucleus cochlear implant receiver/stimulator. The Nucleus Hybrid L24 array has 22 electrodes spread over 16 mm and an anticipated insertion depth of 16 mm. It is slim, with its dimensions ranging from 0.35 x 0.25 mm (at the tip) to 0.55 x 0.4 mm, and designed to minimize lateral wall forces with a stiffened basal section to prevent buckling. The resultant insertion angle is about 280-300° in the scala tympani for the Hybrid L24, as confirmed in temporal bone trials at the Medical University Hannover and the University of Melbourne.<br>|
| Experimental: Children and adolescents (L24)<br>Children (ages 5-12 years) and adolescents (ages 13-15 years) who have a sensorineural hearing loss with a pure-tone average (PTA) between 70-90 dB HL between 125-1500 Hz, a hearing threshold >90 dB HL at 1500 Hz and profound loss at higher frequencies. Intervention: These patients will receive a Hybrid L24 cochlear implant. | Device: Cochlear® Nucleus™ Hybrid L24<br>* The Nucleus Hybrid L24 cochlear implant incorporates an electrode array designed to preserve residual hearing. This has been accomplished by employing a thin, straight, intracochlear electrode array attached to a Nucleus cochlear implant receiver/stimulator. The Nucleus Hybrid L24 array has 22 electrodes spread over 16 mm and an anticipated insertion depth of 16 mm. It is slim, with its dimensions ranging from 0.35 x 0.25 mm (at the tip) to 0.55 x 0.4 mm, and designed to minimize lateral wall forces with a stiffened basal section to prevent buckling. The resultant insertion angle is about 280-300° in the scala tympani for the Hybrid L24, as confirmed in temporal bone trials at the Medical University Hannover and the University of Melbourne.<br>|
| Experimental: Children and adolescents S12<br>Children (ages 5-12 years) and adolescents (ages 13-15 years) who have a sensorineural hearing loss with a pure-tone average (PTA) between 70-90 dB HL between 125-1500 Hz, a hearing threshold hearing threshold between 70-90 dB HL at 1500 Hz and profound loss at higher frequencies. Intervention: These patients will receive a Hybrid S12 cochlear implant. | Device: Cochlear® Nucleus™ Hybrid S12<br>* The Nucleus Hybrid S12 cochlear implant incorporates an electrode array designed to stimulate the high-frequency, basal region of the cochlea while maintaining useful acoustic hearing in the low-frequency, apical region. This has been accomplished by employing a short, thin, straight intracochlear electrode array attached to a Nucleus cochlear implant receiver/stimulator. The electrode array incorporates a collar to prevent over-insertion, or further migration, into the cochlea beyond the point where the basal turn curves into the ascending segment. Thus, the electrode array is placed within the straight segment of the basal turn of the scala tympani via a cochleostomy.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in CNC Word Perception | Pre-operatively, speech perception testing will be conducted using the ear implanted and bilaterally with appropriately fit hearing aids. Post-operatively, speech perception testing will be attempted in the following conditions (unless otherwise noted): Combined stimulation (cochlear implant and any hearing aids worn on the implanted or non-implanted ears) Testing will be in quiet at 60 dB(A). The CNC word perception test consists of multiple lists of 50 3-syllable words (consonant-nucleus-consonant) that are presented through a loudspeaker using an open set format. Percent correct is calculated by the number of words identified by the subject out of the 50 words presented. | pre-op, 3, 6, 12, 24 months in the adults and pre-op, 3, 6, 12, 24, 36, 48, and 60 months post-implantation for children | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Localization | Pre-operatively and post-operative, testing will be conducted using bilaterally fitted devices (preoperatively) and a cochlear implant and bilateral hearing aids (if applicable) postoperatively (combined condition). Everyday sounds will be presented from one of eight loudspeakers at 60 dBA forming a 108- arc. The participant will face the center of the speaker array at a 1.4 m. 16 different sounds will be repeated 6 times and presented randomly from one of the loudspeakers. Localization performance was calculated by the average root-mean-square (RMS) error in degrees. | Preoperatively and at 6 and 24 months post op in adults and pre op and 12 and 24 mos in children | 
| AzBio +5 Noise | Sentences in a +5 dB noise will be administered. Sentences will be tested at 60 dB(A) and noise at 55 dB(A) from the front. Pre-operatively, speech perception testing will be conducted using the ear implanted and bilaterally with appropriately fit hearing aids. Post-operatively, speech perception testing will be attempted in the following conditions (unless otherwise noted): Combined stimulation (cochlear implant and any hearing aids worn on the implanted or non-implanted ears) The AzBio sentence perception test consists of multiple lists of 20 sentences that are presented in sound-field from a loudspeaker using an open set format. Percent correct is calculated by the number of words correctly identified by the subject out of the total number of words presented in the sentence lists. | Adults pre-op, 3, 6, 12, 24 months post op | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
residual hearing, hybrid, hearing preservation