Effect of stylet removal on neural response telemetry and stapedial reflex thresholds during cochlear implantation.

Objective: The purpose of this study was to analyze changes in neural response telemetry (NRT) and electrically evoked stapedial reflex thresholds (ESRT) before and after stylet withdrawal during cochlear implant surgery.

Methods: Thirty children (21-92 months old) who were candidates for cochlear implantation took part in this study. In all of them Nucleus Contour Advance was implanted. NRT and ESRT responses were recorded initially with the stylet in and then when the stylet was taken out during the implant procedure. The recordings were performed in the basal, middle, and apical areas of the electrode array.

Results: The threshold levels required to obtain NRT and ESRT responses after stylet removal were lower. This decrease was observed in all parts of the cochlea. It was statistically significant in all areas with the exception of the basal ESRT measurements.

Conclusions: Withdrawing the stylet results in better NRT and ESRT responses, most probably due to a favorable position change of the electrode array within the scala tympani.