Impact of Cochlear Nerve Deficiency Determined Using 3-Dimensional Magnetic Resonance Imaging on Hearing Outcome in Children with Cochlear Implants. Issue 1 (January 2015)

• Record Type: Journal Article
• Authors: Wu, Che-Ming; Lee, Li-Ang; Chen, Chin-Kuo; Chan, Kai-Chieh; Tsou, Yung-Ting; Ng, Shu-Hang
• Is Part Of: Otology & neurotology. Volume 36:Issue 1(2015)
• Publication Date: 2015-01
• Subjects: Otology -- Periodicals; Ear -- Diseases -- Periodicals; Skull base -- Surgery -- Periodicals; 617.8005
• DOI: 10.1097/MAO.0000000000000568
• Languages: English
• ISSNs: 1531-7129

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Objectives</title> <p>1) To review the radiologic and audiologic data of 656 children with sensorineural hearing impairment who underwent 3-dimensional magnetic resonance imaging (MRI) in our cochlear implant (CI) center to understand the incidence of cochlear nerve deficiency (CND); and 2) to compare postimplant auditory and speech intelligibility outcomes in implantees with cochlear nerve (CN) aplasia, CN hypoplasia, and normal CN.</p> </sec> <sec> <title>Study Design</title> <p>A retrospective cohort study.</p> </sec> <sec> <title>Setting</title> <p>A tertiary medical center.</p> </sec> <sec> <title>Patients</title> <p>A total of 656 patients (aged 0–18 yr; mean, 4.5 ± 4.3 yr) who underwent MRI in our center during May 2000 to December 2012.</p> </sec> <sec> <title>Main Outcome Measures</title> <p>The radiologic/audiologic data were reviewed. The postimplant outcomes of 13 implantees with CND (7 aplasia and 6 hypoplasia) were compared with 50 non-CND implantees using the Categories of Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) scales.</p> </sec> <sec> <title>Results</title> <p>Upon MRI, 139 patients (21.2%) exhibited CND. Bilateral CN aplasia occurred in 4.3% of the patients with severe-to-profound deafness (588 cases) and in one-fifth of patients with CND. The aplasia group showed significantly worse postimplant CAP (<italic>p</italic> = 0.002) and SIR (<italic>p</italic> = 0.009) scores than the non-CND group. No significant difference was noted between the hypoplasia group and the non-CND group.</p> </sec> <sec> <title>Conclusion</title> <p>Although the audiologic and radiologic 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 with patients implanted on the side with CN aplasia.</p> </sec> </abstract>