Abstract
Large vestibular aqueduct (VA) syndrome is a distinct congenital inner ear anomaly characterized by a large aperture in the vestibular aqueduct. Among our outpatients with sensorineural hearing loss (SNHL) of unknown etiology evaluated between 1995 and 1997, the nine patients (17 ears) with large VA are presented.
Their history, in addition to results of physical examination, computed tomography, serial audiograms and vestibular function, were reviewed. The average hearing level of the 17 ears was 70.7dB. Eight ears had severe hearing loss, four ears demonstrated more hearing loss in the highfrequency range than in the low-frequency range, and two ears had normal hearing. Positional nystagmus and positioning nystagmus were found in seven cases. Caloric test findings were as follows; four ears had canal paresis, six ears had vestibular dysfunction and three were normal. CT showed three cases with inner ear anomalies other than large VA syndrome.
Fluctuating, or progressive SNHL was present in four of five patients who were followed over a period of three years. Stable SNHL was present in the one-year-follow-up cases. These observations indicate that the functionality of the inner ear in patients with a large VA varies over the longer term. In three of the cases with fluctuating or progressive SNHL, conservative therapy was performed including intravenous steroid therapy, stellate ganglion block, and Co2 inhalation, which seemed to be of a little benefit. In one patient who became deaf 14 years after the initial examination, cochlear implant surgery was performed. Effective therapy to prevent fluctuating or progressive SNHL remain unknown.
