Effects of Cochlear Implantation on Gustatory Function

Abstract

Objectives: Because of the anatomic position of the chorda tympani in the tympanic cavity, the nerve is at risk during cochlear implantation. The aim of this study was to assess changes in taste sensitivity and in self-ratings of gustatory function after surgery. Methods: Twenty-four patients (mean age, 54 years) who underwent cochlear implantation were investigated. Taste function was tested with a validated test for regional quantitative assessment of sweet, sour, salty, and bitter tastes on each side of the tongue before and 4 days after surgery. Results: The mean taste score was 10.0 (SD, 4.0) before and 8.0 (SD, 4.1) after surgery on the side of the tongue ipsilateral to the operated ear (p = .004). However, only 1 patient reported subjective taste loss due to surgery. Taste testing of the side of the tongue contralateral to the operated ear yielded a score of 10.0 (SD, 4.1) before and 10.9 (SD, 4.5) after surgery (p = .037). Self-ratings of gustatory function did not change significantly as a consequence of the procedure. Conclusions: Our results indicate that cochlear implantation is a relatively safe procedure regarding taste function. Preoperative testing of gustatory function is recommended, at least in those patients who already have undergone operation on the contralateral ear.