The magnetless Clarion® cochlear implant in a patient with neurofibromatosis 2

We present our experience using the Clarion(R) magnetless multichannel cochlear implant with a woman profoundly deafened following bilateral acoustic neuromata as a consequence of neurofibromatosis 2 (NF2). The right neuroma had been previously removed without an attempt at neural preservation. On the left, however, a posterior fossa approach had been taken with the aim of preserving hearing. Although the left cochlear nerve appeared to be undamaged at the end of the operation, no hearing thresholds could be elicited on post-operative audiometry, because of damage either to the cochlear nerve or to the blood supply to the cochlea. Round window electrical stimulation subsequently produced a perception of sound, confirming that the cochlear nerve was capable of functioning and that a cochlear implant would be effective. Because she would need regular magnetic resonance imaging (MRI) to monitor existing and future NF2 lesions, it was decided to use a magnetless Clarion(R) implant, which has been shown to be MRI compatible. We report our experience of using the device in this case and discuss some of the issues related to the provision of cochlear implants to patients with NF2.