Otolith function in Usher type II syndrome.

BACKGROUND

Usher's syndrome type II (USH2) is a rare genetic disorder encompassing hearing loss, vision impairment, and apparent intact vestibular function. Recent research suggests a potential involvement of the otolith vestibular receptors in USH2.

AIMS/OBJECTIVES

Evaluate otolith dynamic function in USH2.

MATERIAL AND METHODS

Twenty-two USH2 (median age 53.9 ± 2.99) and age-matched controls underwent a complete battery vestibular testing including air conducted cervical and ocular vestibular evoked myogenic potentials (c-VEMPs and o-VEMPs). Vestibular function tests were correlated with Activities Balance Scale (ABC) and Dizziness Handicap Inventory (DHI) scores.

RESULTS

Fourteen USH2 reported previous vertigo (vs none control). Among 88 ears, c-VEMPs were absent in 15 USH2 cases and 4 controls (

CONCLUSIONS AND SIGNIFICANCE

Our findings suggest the presence of otolith dysfunction in USH2, which is independent from subjectively reported dizziness. Incorporating vestibular testing into USH2 evaluation and monitoring could enhance characterization of this multisensory disease.