Cochlear Nerve Patency as a Prognostic Factor in Cochlear Implantation in Adults
23 April 2019 (online)
The purpose of this study was to examine various preoperative factors that can play a role in the auditory rehabilitation outcome of CI recipients. In order to determine the level of integrity of central processing preoperatively, special attention was given to residual hearing, duration of deafness, and cochlear nerve diameter as prognostic factors.
Individual retrospective cohort study. A cohort of 204 (242 CI implantations) postlingually deafened adults was evaluated in this study. Hearing results at 12 months postoperatively were compared with various preoperative factors. Postoperative hearing performance was measured based on the German Freiburg monosyllabic word test and the Oldenburg sentence test.
Results remained constant after 12 months of implantation. Duration of deafness showed a negative correlation to word recognition and a positive correlation to increased signal-to-noise-ration in sentence testing. A significant decline in hearing outcome was shown starting in the third decade of deafness duration corresponding to 58% of life spent in deafness.
It could be shown that there is an intricate interaction in the preoperative variables: duration of deafness – as well as the ratio of life spent in deafness; residual hearing; and cochlear nerve diameter.