The characteristic of enlarged vestibular aqueducts syndrome in pure tone audiometry: low frequency air-bone gap / 临床耳鼻咽喉头颈外科杂志

ABSTRACT

OBJECTIVE@#The purposes of this study was to analyse the significant of low frequency air-bone gap in enlarged vestibular aqueduct (EVA) patients according to the pure tone audiogram and the benefit for clinic diagnosis of the EVA.@*METHOD@#The audiology testing include (1) play audiometry or pure tone audiometry, tympanometry, middle ear muscle reflex thresholds and stapedius muscle reflex; (2) High-resolution computed tomography (CT) scan of the temporal bone and magnetic resonance imaging was used for diagnoses the EVA.@*RESULT@#All the 78 patients (154 ears) were diagnosed as the typical EVA by CT or MRI. Inner ear malformations were found in 3 ears otherwise the structures of middle ear in all the patients were absolutely normal. The audiology analysis showed 154 ears were type A tympanogram including 126 ears with typical A, 25 ears with As, 3 ears with Ad type. In the 250 Hz pure-tone testA-B gap were observed in 126 ears(126/154,81. 8%) with the different hearing loss degree 1 ear mild, 11 ears moderate, 19 ears moderate severe, 40 ears severe and 53 ears profound. In the 500 Hz pure-tone test A-B gap were found in 102 ears(102/154, 66. 2%) with the different hearing loss degree 9. ears moderate, 17 ears moderate severe, 35 ears severe and 41 ears profound.@*CONCLUSION@#Our study suggested a 66. 2% -81. 8% possibilities to find the EVA through the pure-tone audiometry firstly in the basis of the normal tympanograms with the significant A-B gap.