A Case of Magnet Displacement in a Cochlear Implant Detected after MRI Corrected by a Non-invasive Approach

Abstract

Cochlear implant is an established auditory prosthesis for children and adults with severe to profound sensorineural hearing loss. With the expansion of the use of cochlear implants, the number of cochlear implant users needing magnetic resonance imaging (MRI) is also increasing.

We report a case of magnet displacement after 1.5 T MRI in a 68-year-old female patient who was using the Hi-Res 90K^TM cochlear implant. The patient complained of severe pain during the MRI. On physical examination, the skin over the internal magnet was found to be swollen. Because of severe tenderness in the region, the patient could not wear the receiver-stimulator. A CT scan showed that the lower end of the internal magnet in the implant had become dislodged from the silicone sheath. In this case, the magnet was repositioned by a non-invasive approach via a percutaneous closed reduction maneuver. Immediately after the repositioning procedure, the tenderness and the bulging of the skin disappeared. At present, 6 months since the procedure, the cochlear implant continues to function well.