Objective: To examine speech perception outcomes as related to a reduction in the number of functional electrodes postimplantation and to determine the effect of electrode reduction on subsequent device failure.
Study design: Retrospective review.
Setting: Tertiary academic referral center.
Patients: Of 1,520 children and adults with full insertions of the Advanced Bionics, Med El, and Nucleus devices, 15 (1%) were patients. Patients were included in the study if all electrodes were functional at initial stimulation, but the number of electrodes in use was subsequently reduced at follow-up programming sessions. Exclusion criteria included partial and split-array electrode insertions.
Intervention(s): Patients with bilateral severe to profound sensorineural hearing loss underwent either unilateral or bilateral cochlear implantation.
Main outcome measure(s): Postimplantation speech perception tests obtained with a full complement of functional electrodes were performed and the results compared to those obtained with 1 or more electrodes removed from the user program. Electrode deactivation was also correlated with device failure.
Results and conclusion: The results of this study indicate that deactivation of cochlear implant electrodes is relatively uncommon, and although the deactivation does not have a direct influence on speech performance outcomes, the loss of 5 or more electrodes can suggest impending device failure. Additionally, those patients with electrode deactivation coupled with a decline in speech perception scores should also be considered at risk for device failure.