Taste Change after Middle Ear Surgery

Lee, Young Ho; Ye, Mi Kyung; Shin, Im Hee

Abstract

BACKGROUND AND OBJECTIVES: During middle ear surgery, surgeons manipulate the chorda tympani nerve (CTN) at various degrees and warn the post-operative taste changes to patients preoperatively. The purpose of this study is to assess how many patients suffer from taste disturbance after surgery and the characteristics of their disease factors and surgical factors in patients complaining of it. In addition, it was designed to evaluate the clinical availability of electrogustometry (EGM)compared with subjective taste symptoms.
SUBJECTS AND METHOD
One hundred thirty-one patients underwent middle ear surgery. Patients were divided to three groups, only tympanoplasty, tympano-ossiculoplasty without mastoidectomy and tympanoplasty with mastoidectomy. They were analysed by operative findings of CTN preserved, stretched, cut. The CTN function was measured at one day before surgery and one month after surgery by EGM. Taste questionnaires were given to all patients before and after surgery for one year. The results of EGM and questionnaires were compared with each other.
RESULTS
In pre-operative EGM results of unilateral surgery, the lesion side of tongue had more elevated threshold of EGM than the contralateral side. In the post-operative EGM, any statistical factor was not significant and EGM results was not correlated with subjective symptoms. The results of the test questionnaraires was that thirty-three patients (25%) reported taste change. In tympanoplasty-preserved CTN group, more patients suffered from taste change than mastoidedctomy-cut CTN group. Symptoms were decreased taste sensation, dysgeusia, and decreased general sensation of tongue. Subjective recovery time was on the average of 2.7 months (two weeks to one year) after surgery.
CONCLUSION
EGM was not correlated with subjective symptoms after surgery. Iatrogenic CTN injury in advanced middle ear infection may not cause taste disturbance. Surgeons should have efforts to preserve CTN in even mild middle ear diseases.