Auditory Brainstem Implantation after Unsuccessful Cochlear Implantation in Children with Cochlear Nerve Deficiency

Abstract

Objectives: To compare perceptual auditory abilities in 31 children with cochlear nerve deficiency (CND) and surgically verified absent cochlear nerve absence (ACN), receiving first a cochlear (CI) and subsequently an auditory brainstem implant (ABI). Methods: Thirty children initially received a CI at outside institutions and failed to progress in perceptual auditory abilities between 2000 and 2013. Explantation of the CI and ABI placement were performed on the same side. Revision of all surgical videos to determine presence or absence of the cochlear nerve. Perceptual auditory abilities obtained after the CI and after the ABI were converted to the Category of Auditory Performance (CAP) scale. Results: All children had severe to profound sensorineural hearing loss (SNHL) and CND. Magnetic resonance imaging documented ACN in 18 and small cochlear nerve (SCN) in 13 children. The internal auditory canal (IAC) was atretic in 8 and of reduced diameter in 12 children. At surgery, all patients demonstrated ACN. With cochlear implants, all patients had a CAP less than or equal to 2. With ABI, All patients had a CAP greater than or equal to 2. The complication rate was similar between CI and ABI patients. Conclusions: Children with a clinical diagnosis of CND and imaging of ACN and SCN, fitted with CIs have an extremely poor prognosis. In these children the opportunity for developing open set speech perception and acquiring speech may be better achieved with ABI placement. The overall complication rate of ABI is not greater than that of CI.