Relationship between the external aperture and hearing loss in large vestibular aqueduct syndrome.
BACKGROUND
Large vestibular aqueduct syndrome (LVAS) is a major cause of hearing loss in childhood. This study aimed at measuring external aperture of enlargement of the vestibular aqueduct (EVA) and analyzing relationship between the size of external aperture and hearing loss.


METHODS
Diagnostic criteria of LVAS were based on hearing loss and CT images. CT images of temporal bone of 100 LVAS patients were collected and 60 control subjects were reviewed retrospectively in the past 10 years. A battery of audiometric and vestibular function tests were performed. The width of the vestibular aqueduct (VA) was measured on axial CT images of the temporal bone.


RESULTS
One hundred patients (65 men, 35 women) were diagnosed as having the isolated EVA. Hearing loss mostly occurred in early childhood. The diagnosis age of LVAS was 7.7 years on average. The causes of hearing loss could not be confirmed by initial consult. Typically, audiometric curve is the high-frequency down-sloping configuration. 92% of the cases had severe or profound sonsorineural hearing loss (SNHL). The mean size of the external aperture was (7.5 +/- 1.2) mm in present LVAS. Statistical analysis showed that the degree of hearing loss is unrelated to the width of VA.


CONCLUSIONS
LVAS is a distinct clinical entity characterized by fluctuating, progressive SNHL. The degree of hearing loss is unrelated to the size of external aperture of VA. The protective management and hearing aid have become the main therapies. The cochlear implantation might be performed if the hearing loss affected learning at school.
Zhang
Su-zhen
SZ
Department of Otorhinolaryngology, Head and Neck Surgery, General Hospital of Chinese PLA, Beijing 100853, China.
Yang
Wei-yan
WY
Wu
Zi-ming
ZM
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003951:Diagnostic Errors; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000209:etiology*; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D013577:Syndrome; D014057:Tomography, X-Ray Computed; D014723:Vestibular Aqueduct / Q000002:abnormalities* / Q000473:pathology