Multichannel cochlear implantation with inner ear malformation: case report of performance and management.

A small percentage of children who have received the Nucleus multichannel cochlear implant have cochlear malformations of the inner ear and consequent partial electrode insertions. This case describes one child with a cochlear "common cavity" who received an implant at a young age. The case has been further complicated by a gradual malfunction of the electrode array, although the device has not failed completely. Despite the increase in the number of nonfunctional electrodes over time, the subject has continued to improve in auditory, speech production, and language development over a 30-month period. Methods are discussed for clinical monitoring of both performance and the stability of electrodes over time. The circumstances of this case reinforce the importance of postimplant collaboration with families and school staff and highlight the need for objective measures to evaluate both longitudinal changes in performance and device integrity.