Relationship between the external aperture and hearing loss in large vestibular aqueduct syndrome:

Effect of High Jugular Bulb on the Hearing Loss Characteristics in Patients With LVAS: A Pilot Study

Objective

Both large vestibular aqueduct syndrome (LVAS) and high jugular bulb (HJB) are regarded as abnormalities commonly seen on the temporal bone CT. High jugular bulb has been found to erode the vestibular aqueduct, and there are several studies on jugular bulb vestibular aqueduct dehiscence. However, there is no study that specifically reports LVAS with concurrent HJB and its hearing loss relatedness. This study presents the pure tone audiometry differences between LVAS with HJB, and LVAS without HJB.

Methods

This was a case control study involving 36 bilateral LVAS with concurrent unilateral HJB patients, total of 72 ears. Intra-person comparison was done, by dividing ears into two groups: the case group, 36 ears (LVAS with HJB); and the control group, 36 ears (LVAS without HJB). Air conduction thresholds (250–4000 Hz), bone conduction thresholds (250–1000 Hz), and air bone gap (250–1000 Hz) were analyzed and compared between groups.

Result

There were statistically significant differences in AC thresholds at 250, 500, 2000, and 4000 Hz between the groups, p < 0.05. But there was no statistical significant difference at 1000 Hz, p > 0.05. There were statistical significant differences in BC thresholds at 250 and 500 Hz, p < 0.05, but there was no statistical difference at 1000 Hz. There were no significant differences in air bone gap at 250, 500, and 1000 Hz between the two groups.

Conclusion

LVAS with concurrent HJB was found to have higher air conduction thresholds, especially at 250, 500, 2000, and 4000 Hz. Bone conduction thresholds were higher at 250 and 500 Hz. Air bone gap at 250, 500, and 1000 Hz, were not significantly higher in LVAS with concurrent HJB.

Systematic Review on Vestibular Symptoms in Patients With Enlarged Vestibular Aqueducts

OBJECTIVE

Enlarged vestibular aqueduct (EVA) is a congenital condition that can lead to various outcomes in pediatric patients including hearing loss and vestibular dysfunction. Our goal was to critically appraise the literature on the proportion of patients with EVA who report vestibular dysfunction, determine relevant risk factors for the development of these symptoms, and describe vestibular tests and interventions used to improve outcomes.

METHODS

A systematic review was performed in accordance with the PRISMA guidelines. We queried the EMBASE, Ovid Medline, and Cochrane Library databases for relevant literature. Studies were included if they had n > 10, reported vestibular symptoms or vestibular function testing in patients with EVA, and were published in English. Nonhuman studies, systematic reviews, and review articles were excluded.

RESULTS

Of 808 identified studies, 20 met inclusion criteria. Subjective vestibular symptoms included dizziness, episodic vertigo, and imbalance. Seventeen studies reported subjective vestibular symptoms, ranging from 2% to 71% of patients between studies. Seventeen studies performed some form of vestibular function test, including physical exam maneuvers (Dix-Hallpike), caloric testing, electronystagmography, and vestibular evoked myogenic potentials. Of those who had vestibular function testing, 7% to 92% had an abnormal result. Two studies identified head trauma as a risk factor. One study successfully treated patients with BPPV using the Epley maneuver, but other vestibular symptoms were not targeted with treatment.

CONCLUSION

The degree to which vestibular symptoms impact patients with EVA varies significantly. Performing vestibular function testing may help identify asymptomatic patients with vestibular dysfunction. Future studies should target improving treatment of vestibular symptoms in EVA patients. Laryngoscope, 2021.

[Enlarged vestibular aqueduct syndrome: etiology, clinical features, diagnostics, and rehabilitation of the patients]

This publication was designed to describe the clinical manifestations of the enlarged vestibular aqueduct syndrome (EVAS), the currently employed methods for its diagnostics, and the strategy for the rehabilitation of the patients presenting with this pathological condition. In addition, the article provides information about the topographic anatomy and X-ray anatomy of the vestibular aqueduct, the specific clinical features of EVAS, the modern algorithm of its diagnostics, and the facilities for hearing rehabilitation in this group of patients.

Enlarged vestibular aqueduct in congenital non-syndromic sensorineural hearing loss in egypt

To estimate the frequency of isolated enlarged vestibular aqueduct (EVA) in patients with non-syndromic sensorineural hearing loss (SNHL) in an Egyptian population sample and to correlate its size with the degree of hearing loss. The study group comprised 16 patients (32 ears) suffering from non-syndromic SNHL since childhood. After a complete basic audiological evaluation, all patients were submitted to non contrast CT scan of the petrous bone in both axial & coronal planes. Vestibular aqueduct (VA) was measured at two points (midpoint & operculum) on right & left sides. The study group was divided according to VA size into three groups: group A, B and C. Group A included 6 ears (4 patients) with EVA, group B included 11 ears (7 patients) with borderline EVA and group C included 15 ears (9 patients) with normal VA size. There were no statistically significant differences between the three groups as regards laterality, degree of hearing loss and audiometric configuration. There was no correlation between VA midpoint & operculum and different variables (age and average pure tone thresholds). However, a significant correlation between VA midpoint & operculum was found. EVA was diagnosed in 6 out of 32 ears (18.75%) in the study sample. EVA size was not related to the degree of hearing loss or configuration. Despite the insignificant findings, moderate and high frequency sloping SNHL were considered the most common findings seen in patients with EVA.

The relationship between vestibular aqueduct diameter and sensorineural hearing loss is linear: a review and meta-analysis of large case series

INTRODUCTION

Inner ear homeostasis is dependent on the vestibular aqueduct and its content, the endolymphatic duct. Narrow and enlarged vestibular aqueducts have both been associated with hearing loss in Ménière's and large vestibular aqueduct syndromes. This review investigated the correlation between vestibular aqueduct diameter and pure tone average, and the effect of measurement site (i.e. the midpoint or the external aperture).

MATERIALS AND METHODS

A systematic review of the literature and meta-analysis of large case series published on the Allied and Complementary Medicine, British Nursing Index, Cumulative Index to Nursing and Allied Health, Embase, Health Business Elite, Health Management Information Consortium, Medline, PsycInfo and PubMed databases. References and personal books were also scrutinised.

RESULTS

A linear relationship between vestibular aqueduct diameter and hearing loss was observed, with a projected increase of 6 dBHL per unit of vestibular aqueduct diameter (95 per cent confidence interval, 2-10; p = 0.003). This relationship was independent of measurement site.

DISCUSSION

This dose-dependent or linear relationship supports the role of flow and/or pressure change as aetiological factors in the pathogenesis of hearing loss, as per Poiseuille's law. This aetiological association is strengthened by the fact that the observed relationship is independent of measurement site.

The development of auditory skills in infants with isolated Large Vestibular Aqueduct Syndrome after cochlear implantation

OBJECTIVE

The purpose of this study was to investigate the auditory performance of infants with isolated Large Vestibular Aqueduct Syndrome (LVAS) after cochlear implantation, compare their performance with those of infants with a normal inner ear, and establish a database of auditory development.

METHOD

435 infants with congenital severe to profound hearing loss participated in this study. 62 infants in group A were diagnosed with isolated LVAS. 373 infants in group B had a normal inner ear. Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) was used to evaluate the development of auditory skills.

RESULTS

The mean scores for auditory ability showed no significant difference between groups A and B. The mean scores for the three different auditory skills increased significantly over time. The differences were statistically significant in mean scores among the three different auditory skills for group B.

CONCLUSION

Auditory skills of infants with isolated LVAS developed rapidly after cochlear implantation, in a similar manner to those of infants with a normal inner ear. Cochlear implantation is an effective interventional approach and an established therapeutic option for infants with isolated LVAS.

Communication routes between intracranial spaces and inner ear: function, pathophysiologic importance and relations with inner ear diseases

OBJECTIVE

There exist 3 communication routes between the intracranial space and the inner ear, the vestibular aqueduct, the cochlear aqueduct, and the internal auditory canal. They possess a key role in inner ear pressure regulation and fluid homeostasis and are related to inner ear diseases.

REVIEW METHODS

Relevant literature was reviewed, and the current knowledge of the anatomy, physiologic importance, and relations to inner ear diseases were described. Pathologic communication routes such as semicircular canal dehiscence syndrome were highlighted as well.

CONCLUSION

Abnormalities in all 3 communication routes may predispose or be the cause of distinct inner ear pathologic condition and involved in other cochlear and vestibular syndromes, in which their role is not completely clear. The increasing knowledge of the underlying mechanisms encourages promising approaches for possible intervention in the future.