Otolaryngology: Open Access
Open Access

Abstract

Objectives: (1) To review the radiological and audiological data of 656 children with sensorineural hearing impairment who underwent three-dimensional magnetic resonance imaging (MRI) in our cochlear implant (CI) center to understand the incidence of cochlear nerve deficiency (CND); (2) to compare post-implant auditory and speech intelligibility outcomes in implantees with cochlear nerve (CN) aplasia, CN hypoplasia and normal CN. Study Design: A retrospective cohort study. Setting: A tertiary medical center. Patients: 656 patients (aged 0-18 years, mean=4.5±4.3 years) who underwent MRI in our center during May 2000 to December 2012. Main outcome measures: The radiological/audiological data were reviewed. The post-implant outcomes of 13 implantees with CND (7 aplasia, 6 hypoplasia) were compared with 50 non-CND implantees using the Categories of Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) scales. Results: Upon MRI, 139 patients (21.2%) exhibited CND. Bilateral CN aplasia occurred in 4.3% of the patients with severeto- profound deafness (588 cases) and in one fifth of patients with CND. The aplasia group showed significantly worse postimplant CAP (p=0.002) and SIR (p=0.009) scores than the non-CND group. No significant difference was noted between the hypoplasia group and the non-CND group. Conclusions: Although the audiological and radiological results may be incompatible, the majority of patients with CND may be well-delineated preoperatively using MRI. The type of CND (aplasia/hypoplasia) may affect CI outcomes. Patients implanted on the side with CN hypoplasia are more likely to exhibit favorable results compared to patients implanted on the side with CN aplasia.

Biography

Che-Ming Wu is a Clinical Associate Professor and Head of Otology of Department of Otolaryngology-Head and Neck Surgery, Chang-Gung Memorial Hospital. He is the Executive Councilor and the Chairman of Hearing and Language Training Committee of Taiwan Otolaryngology-Head and Neck Surgery Society. Having been in the field of otology for over 20 years, he has operated on over 5000 patients with middle ear and inner ear diseases and performed more than 300 cochlear implant surgery in Taiwan. For nearly 10 years, he has dedicated his time in the long term follow-up of the outcome of his cochlear implanted patients.