Effect of Initial Switch-On Within 24 Hours of Cochlear Implantation Using Slim Modiolar Electrodes: Potential Clinical Implications

Abstract Reducing electrode impedance is an important factor in improving the functional benefits of cochlear implants (CIs). The immediate effect of early switch-on within 24 hours of surgery on impedance among CI recipients with various types of electrodes has been reported previously; however, the immediate change and the evolution of electrode impedances of slim modiolar electrodes after early switch-on within 24 hours of implantation has not. Therefore, the focus of this study was to compare the effect of early switch-on and conventional switch-on 3–4 weeks post-operation on impedance. Compared with impedance measured intraoperatively, our results demonstrate a significant drop in impedance for early switch-on, which sharply contrasted with elevated impedance values for conventional switch-on 3–4 weeks after implantation. Notably, a comparatively lower impedance than the conventional switch-on protocol was observed for up to 2 months post-operation. Most importantly, a much earlier stabilization of impedance can be achieved with the early switch-on protocol coupled with the slim modiolar electrode array compared to the conventional switch-on protocol, offering the advantage of reducing the number of required mapping sessions in the early stages of rehabilitation.