Facial nerve stimulation produced by cochlear implants in patients with cochlear otosclerosis

Thirty-eight adult cochlear implants have been performed at the University of Minnesota. Facial nerve stimulation by the implant in response to sound has been noted in four of these cases. Three of the four were patients whose sensorineural hearing loss was caused by cochlear otosclerosis. In each case it was possible to place the electrodes, however multiple leads had to be deprogrammed in order to avoid facial nerve stimulation. In each case characteristic radiographic findings of cochlear otosclerosis could be identified on preoperative temporal bone computed tomography scans. Although facial nerve stimulation has been described as a complication of cochlear implantation, it has not been reported to be associated with cochlear otosclerosis. Postoperative programming of the implant may be limited by facial nerve stimulation. In some cases these limits may reduce the efficacy of the device. This possibility should be taken into account during preoperative counseling of patients with cochlear otosclerosis considering cochlear implantation.