Averaged Electrode Voltage Testing to Diagnose an Unusual Cochlear Implant Internal Device Failure

This paper describes an unusual Clarion 1.2 cochlear implant failure in order to demonstrate the need for the clinical availability of electrode voltage testing. The case report describes a patient with a Clarion 1.2 cochlear implant who exhibited poor auditory progress in spite of grossly normal impedances and electric field testing, and an appropriate educational and psychosocial environment. For a subset of electrodes, however, electrode voltage testing was abnormal. At explantation it was found that the epoxy that protects the connection between the electrode leads of the array and the output contacts on the internal controller had fractured. This failure was not associated with reported head trauma. This case report demonstrates the utility of and clinical need for electrode voltage testing as a helpful tool to diagnose internal device failure.

Key Words

Cochlear implant - device failure - electrode voltage