Facial nerve stimulation after cochlear implantation according to types of Nucleus 24-channel electrode arrays

Abstract

Conclusion. In this study, we concluded that electrode design and location did not have a high level of influence on the prevalence of facial nerve stimulation (FNS) in normal cochleae. Objective. To analysis the prevalence of FNS after cochlear implantation with Nucleus 24-channel devices according to types of electrodes arrays. Patients and methods. We retrospectively analyzed medical and mapping records of 394 patients who received cochlear implants (CIs) manufactured by Cochlear Corporation from April 1999 to March 2007. Results. In all, 23 of 394 (5.8%) patients had FNS (CI24M 4 of 39 [10.3%], CI24RCS 9 of 192 [4.7%], CI24RST 9 of 21 [42.9%], and CI24RECA 1 of 87 [1.1%]). In addition, 4 of 324 (1.2%) patients with normal cochleae complained of FNS (CI24M 1 of 33 [3.0%], CI24RCS 2 of 173 [1.2%], and CI24RECA 1 of 71 [1.4%]). There was no difference between straight and perimodiolar electrode arrays in patients with normal cochleae. In addition, when comparing two types of Contour™ electrodes, Contour Advance™ (soft-tip) electrodes offered significantly lower incidence of FNS than Contour™ electrode arrays. We could manage these patients with methods such as decrease of C-level, selective channel turning off, and changes of mapping strategies.