Taste function after stapes surgery.

OBJECTIVE: A manipulation of chorda tympani nerve (CTN) is frequently necessary during the surgical therapy of stapedial ankylosis. The aim of this study was to re-assess the taste function before and after stapes surgery in patients with unilateral stapes ankylosis.
METHODS: Eighteen patients (14 female and 4 male) with unilateral stapedial ankylosis were included. Taste and olfactory function were measured preoperatively, 3 days and 3 months after surgery by questionnaire, chemical taste test, electrogustometry, and Sniffin'Sticks. The patients who reported deterioration in taste and revealed pathological taste test results were re-investigated 8-12 months after surgery. Postoperatively 11 patients were treated intravenously for 3 days for inner ear protection with 1g of cortisone. The gustatory and olfactory results were compared with age and sex specific normative data.
RESULTS: A significant transient decrease of gustatory measurement values was found on the ipsilateral two thirds of the anterior tongue. 12 out of 17 patients whose CTN was slightly manipulated during stapes surgery reported tongue sensations, such as numbness or gustatory blindness of the ipsilateral tongue side. The measures of chemical taste test significantly decrease in lateralized taste test on the ipsilateral side and in whole mouth testing. There was no significant increase of the EGM measures at the ipslateral tongue. In 11 of 12 patients with symptoms, complaints recovered within one year after surgery completely. The factor "cortisone" did not have a significant effect on the taste test results after surgery.
CONCLUSION: In conclusion, even after minor CTN manipulation the rate of postoperative taste disorders or tongue symptoms after stapes surgery is high. The symptoms appear to be transient. Therefore CTN should be preserved in stapes surgery after mild trauma of the CTN. Transient taste alteration should be mentioned prior to stapes surgery.