Bilateral cochlear implants in infants: a new approach--Nucleus Hybrid S12 project.

OBJECTIVE

The purpose of this feasibility study was to evaluate whether the use of a shorter-length cochlear implant (10 mm) on one ear and a standard electrode (24 mm) on the contralateral ear is a viable bilateral option for children with profound bilateral sensorineural hearing loss. A secondary purpose of this study was to determine whether the ear with the shorter-length electrode performs similarly to the standard-length electrode. Our goal was to provide an option of electrical stimulation that theoretically might preserve the structures of the scala media and organ of Corti.

STUDY DESIGN

The study is being conducted as a repeated-measure, single-subject experiment.

SETTING

University of Iowa-Department of Otolaryngology.

PATIENTS

Eight pediatric patients with profound bilateral sensorineural hearing loss between the ages of 12 and 24 months.

INTERVENTIONS

Nucleus Hybrid S12 10-mm electrode and a Nucleus Freedom implant in the contralateral ear.

MAIN OUTCOME MEASURES

The Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) parent questionnaire, Early Speech Perception, Glendonald Auditory Screening Procedure word test, and Children's Vowel tests will be used to evaluate speech perception and the Minnesota Child Development Inventory and Preschool Language Scales 3 test will be used to evaluate language growth.

RESULTS

Preliminary results for 8 children have been collected before and after the operation using the IT-MAIS. All 3 children showed incremental improvements in their IT-MAIS scores overtime. Early Speech Perception, Glendonald Auditory Screening Procedure word test, and Children's Vowel word perception results indicated no difference between the individual ears for the 2 children tested. Performance compared with age-matched children implanted with standard bilateral cochlear implants showed similar results to the children implanted with Nucleus Hybrid S12 10-mm electrode and a Nucleus Freedom implant in contralateral ears.

CONCLUSION

The use of a shorter-length cochlear implant on one ear and a standard-length electrode on the contralateral ear might provide a viable option for bilateral cochlear implantation in children with bilateral profound sensorineural hearing loss. Further study of this patient population will be continued.