Familial large vestibular aqueduct syndrome

Audiological findings in large vestibular aqueduct syndrome

An enlarged vestibular aqueduct is a congenital disorder causing early onset and progressive hearing loss in children. This paper presents the audiological findings at first presentation and the audiological evolution in 10 consecutive cases presenting with hearing loss and showing a large vestibular aqueduct on imaging. The reported onset of the hearing loss is within the first few years of life. Most of the cases (80%) showed bilateral involvement. The sex ratio was 1. Patients presented on average at age 5 with a median hearing loss of 62 dB at the speech frequencies. The hearing loss was essentially asymmetrical with an interaural difference, of 33 dB and it was a mixed type of hearing loss in 90% of the cases. The authors claim that the conductive component of this hearing loss is a pure cochlear conductive loss which may be pathognomonic for the disease. The presence of a conductive component in a child is easily misinterpreted as a middle ear ventilation problem or in case of good ventilation as an ossicular problem (type otosclerosis). In addition and in contrast to most literature data, the authors did not find evidence for stabilization of the hearing loss but they found a steady decrease of the hearing at an average rate of 4 dB/year.

Vestibular disturbance in patients with large vestibular aqueduct syndrome (LVAS)

Large vestibular aqueduct syndrome (LVAS) is a common inner ear anomaly responsible for some unusual vestibular and audiological symptoms. The gross appearance of CT scan of the inner ear is generally normal. However, precise measurement of the inner ear components reveals abnormal dimensions, which may account for accompanying auditory or vestibular dysfunction. It has been reported that sudden increase in cerebrospinal fluid pressure can cause further deterioration of hearing due to transmission of pressure to the inner ear through the enlarged vestibular aqueduct. However, vestibular function is not often studied. In this report, audiovestibular function of 10 patients with large vestibular aqueducts was analysed and compared with the severity of the radiological deformity. The literature was reviewed and typical findings were discussed to emphasize varying aspects of audiovestibular function. It was found that some patients with LVAS have some spontaneous or provoked vestibular disturbance such as vertigo after watching revolving objects. The mean value of electronystagmographic abnormality in patients with hearing loss is greater than in patients with normal hearing. However, there is no statistical correlation between the level of hearing loss, electronystagmographic abnormality and severity of radiological deformity.

The large vestibular aqueduct syndrome: the role of cochlear implantation in its management

In recent years the large vestibular aqueduct syndrome has become an increasingly recognized cause of a progressive sensorineural hearing loss. Cochlear implantation, although not correcting the bony abnormality, does offer an avenue for rehabilitation for affected individuals and initial results are encouraging. Of 15 patients identified with the large vestibular aqueduct syndrome we have implanted seven (five adults and two children). All patients underwent an uneventful electrode insertion with uncomplicated postoperative periods. Three of our adult patients are showing very good initial results with BKB speech recognition scores of 100%, 74% and 66% with the implant alone. It is still early days with the children, but initial results are encouraging. A full review of the large vestibular aqueduct syndrome is given along with our results.

Single gene influences on radiologically-detectable malformations of the inner ear

Inner ear malformations associated with hearing loss or vestibular dysfunction are discussed from the viewpoint of the etiologies of the malformation. Symptoms of classification of inner ear malformations are discussed. The significance of malformations of the cochlea and vestibular aqueduct to auditory function are discussed. Genetics features and characteristics of Branchio-oto-renal, Waardenburg's, Pendred's, DiGeorge's, Wildervanck, Fountain, and Treacher Collins syndromes are discussed in relation to ear abnormalities and hearing. Similar attention is given to genetic studies of nonsyndromic hearing loss.

Three familial cases of hearing loss associated with enlargement of the vestibular aqueduct

The present report describes three familial cases of recessive hearing loss associated with enlargement of the vestibular aqueduct (EVA). Six siblings from three families showed EVA. The common characteristic of these patients was the presence of congenital, high-frequency, fluctuating sensorineural hearing loss. These cases suggest that EVA may be a useful discriminator between different types of recessive hearing loss.