gms | German Medical Science

Introduction: The fixation of a headset for a cochlear implant (CI) is usually provided with a magnet. However, ferromagnetic materials are considered relative contraindications for MRI. When MRI-imaging is essential in case of special comorbidities, a magnetless CI may be an interesting alternative.

Material and methods: We report on a patient who developed bilateral deafness due to a Cogan-syndrome. He had been implanted with a magnetless CI of Advanced Bionics some years earlier, because a simultaneous disseminated encephalitis afforded repeated MRI-controls postoperatively. The still as an engineer employed patient, wished a bilateral implantation to improve his speech understanding in noisy surroundings.

Results: The patient chose a HiRes® 90K Implant of Advanced Bionics due to his positive experiences with this company. As a consequence of the above mentioned issues we decided in consent with the patient to exchange the implants magnet with a non-ferromagnetic dummy during the implantation. The problem of fixation of the headpiece was solved by a custom made ear mould with a wire construction to the region of the CI. The position of the implant was untypically placed further anteriorly, and the long axis cranially to achieve a small as possible torque on the ear mould. The implantation and the postoperative course were completely uneventful. The fitting of the speech processor could be managed easily. The construction enabled a a stable and ergonomic positioning for the ear mould and headset for our patient.

Conclusion: This case proves the possibility of a magnetless cochlear implantation in special cases. An appropriate planning of the implants location is mandatory during surgery.