Unilateral Enlarged Vestibular Aqueduct Syndrome and Bilateral Endolymphatic Hydrops

Hearing, balance, and imaging assessment in adolescent Menière's disease: A retrospective analysis

Objective

To retrospectively analyze clinical features in adolescent Menière's disease (MD).

Methods

The medical records of adolescents with MD (11-17 years old) from May 2014 to March 2023 in Shandong Provincial ENT Hospital were retrospectively analyzed, including clinical features, a battery of auditory and vestibular function tests, sensory organization test, and imaging assessments. Patients with recurrent vertigo of childhood (RVC) were as controls.

Results

Compared with RVC, adolescent MD showed higher pure tone average threshold (p < .001), lower speech discrimination score (p = .014), and lower otoacoustic emission pass rates (p = .005). Adolescents with MD exhibited significant reduction in equilibrium score (Conditions 1, 5, and 6; p1 = .035; p5 = .033; p6 = .003), composite sensory score (p = .014), and vestibular sensory score (p = .029). Adolescents with bilateral MD exhibited worse performance in equilibrium score and strategy score compared to adolescents with unilateral MD. For the affected ear, the more severe endolymphatic hydrops detected by gadolinium-enhanced magnetic resonance imaging, the higher the auditory brainstem response threshold (r = .850, p = .007), and the lower the otoacoustic emission pass rate (r = -.976, p < .001).

Conclusion

Adolescent MD has similar vestibular information inputs with that of RVC, but the ability for the nerve center to use these clues to maintain balance is worse in adolescents with MD. There were potential differences in vestibular weights in adolescents with unilateral and bilateral MD, also potential effects on vision and proprioception.

Level of Evidence

Level 4.

Understanding the Pathophysiology of Congenital Vestibular Disorders: Current Challenges and Future Directions

In congenital vestibular disorders (CVDs), children develop an abnormal inner ear before birth and face postnatal challenges to maintain posture, balance, walking, eye-hand coordination, eye tracking, or reading. Only limited information on inner ear pathology is acquired from clinical imaging of the temporal bone or studying histological slides of the temporal bone. A more comprehensive and precise assessment and determination of the underlying mechanisms necessitate analyses of the disorders at the cellular level, which can be achieved using animal models. Two main criteria for a suitable animal model are first, a pathology that mirrors the human disorder, and second, a reproducible experimental outcome leading to statistical power. With over 40 genes that affect inner ear development, the phenotypic abnormalities resulting from congenital vestibular disorders (CVDs) are highly variable. Nonetheless, there is a large subset of CVDs that form a common phenotype of a sac-like inner ear with the semicircular canals missing or dysplastic, and discrete abnormalities in the vestibular sensory organs. We have focused the review on this subset, but to advance research on CVDs we have added other CVDs not forming a sac-like inner ear. We have included examples of animal models used to study these CVDs. Presently, little is known about the central pathology resulting from CVDs at the cellular level in the central vestibular neural network, except for preliminary studies on a chick model that show significant loss of second-order, vestibular reflex projection neurons.