Author(s)
Kristin A. Tissera
Alisha Williams, MPH
Leila Mankarious, MD
Affiliation(s)
Massachusetts Eye and Ear Infirmary, Boston, MA.
Abstract:
Introduction: Large vestibular aqueduct syndrome (LVAS) is one of the most common causes of sensorineural hearing loss for patients with an identified etiology. For those who are unilaterally affected, other investigators have described a 28% risk of progressive hearing loss in the radiologically normal ear. Due to the possibility of a decline in the better-hearing ear, there is a growing trend to consider early cochlear implantation in the poorer-hearing ear. We aim to determine the rate of hearing loss in radiologically-unaffected ears of patients with unilateral LVAS defined by the Valvassori criteria.
Methods: 5-year incremental PTA fluctuations were calculated for each patient in the affected ear (AE) versus unaffected ear (UE), and reported as a mean (x̅)with a standard deviation (σx̅).
Results: For patients 0-5 years (n = 9): average threshold shift in the affected ear (AE x̅)was −11.1dB, with a standard deviation (AE σx̅) of 26.97dB. The average threshold shift in the unaffected ear (UE x̅)was +9dB, with a standard deviation (UE σx̅) of 7.78dB. The percentage of patients who experienced a decline in PTA of greater than 10dB between 0-5 years was 22% AE and 0% UE. For patients 5-10 years (n = 15): AE x̅:−7.87dB, AE σx̅: 9.45dB. UE x̅:+1.07dB, UE σx̅: 4.71dB.The percentage of patients who experienced a decline in PTA of greater than 10dB between 5-10 years was 33% AE and 0% UE. For patients 10-15 years (n = 18). AE x̅:−0.1dB, AE σx̅: 5.33dB. UE x̅:−1.83dB UE σx̅: 5.78. The percentage of patients who experienced a decline in PTA of greater than 10dB between 10-15 years was 6% AE and 6% UE. For patients 15-20 years (n = 6). AE x̅:−2.5dB, AE σx̅: 7.18dB. UE x̅:−3.5dB, UE σx̅: 3.73dB. The percentage of patients who experienced a decline in PTA of greater than 10dB between 15-20 years was 17% AE and 0% UE.
Conclusion: Ultimately, we identified that for patients with unilateral LVAS, there was little shift in hearing levels in the radiologically-unaffected ear in all age groups and a progressive stabilization of hearing after age 10y in radiologically-affected ears. These findings suggest the need for repeat study with larger patient numbers and a universal definition of LVAS. When recommending hearing amplification for patients with unilateral LVAS, consideration of the stability of the unaffected ear should be taken into account.