Taste disturbance after stapes surgery--clinical and experimental study.
CONCLUSIONS
Most of the clinical cases experienced taste disturbance after stapes surgery, and in a few cases this disturbance persisted for a long time. The animal experiment suggested the role of geniculate ganglion (GG) cells in nerve generation.


OBJECTIVE
To clinically examine taste disorder and its recovery after stapes surgery and experimentally demonstrate a role of GG.


METHODS
Taste function after preservation of chorda tympani nerve (CTN) in stapes surgery was prospectively investigated with a questionnaire and electrogustometry (EGM). Further, expression of neurotrophic factors in GG after injury of CTN was examined by in situ hybridization histochemistry (ISSH) and RT-PCR.


RESULTS
Among the cases, 15/18 (83.3%) were associated with taste disturbance and 6/18 (33.3%) were associated with tongue numbness 2 weeks after surgery; however, the symptoms ceased in 14/18 cases (77.8%). Two weeks after surgery, the EGM threshold was found to be elevated in 15/18 cases (83.3%), while in 10/18 cases (55.6%), it did not decrease until 1 year after surgery. Expression of ISSH and amplified bands of BDNF and GFR increased at 7 and 14 days after nerve injury in ipsilateral GGs and also increased at 7 days on the contralateral side.
Department of Otolaryngology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
Shinya
S
Miuchi
Masafumi
M
Sakagami
Kenzo
K
Tsuzuki
Koichi
K
Noguchi
Yasuo
Y
Mishiro
Hirokazu
H
Katsura
D000328:Adult; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D002814:Chorda Tympani Nerve / Q000293:injuries; D005260:Female; D005830:Geniculate Ganglion / Q000378:metabolism; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors / Q000378:metabolism; D006801:Humans; D006987:Hypesthesia / Q000209:etiology; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D010040:Otosclerosis / Q000601:surgery; D011183:Postoperative Complications; D011446:Prospective Studies; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013201:Stapes Surgery; D011795:Surveys and Questionnaires; D013651:Taste Disorders / Q000209:etiology*; D013652:Taste Threshold; D014059:Tongue / Q000294:innervation
D019208:Brain-Derived Neurotrophic Factor; C494989:Gfra1 protein, rat; C494995:Gfra3 protein, rat; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D012333:RNA, Messenger