Inner Ear Test Battery Aligned with Hydrops Magnetic Resonance Imaging to Differentiate Acute-Onset Sensorineural Hearing Loss.

INTRODUCTION

This study differentiates cases of acute-onset sensorineural hearing loss (SNHL) that did not meet the diagnostic criteria for either sudden SNHL or Meniere's disease, leading to a diagnostic challenge.

METHODS

All 46 patients with acute-onset SNHL underwent an inner ear test battery followed by hydrops magnetic resonance imaging (MRI). Twenty-four patients (28 ears) who tested positive for endolymphatic hydrops (EH) on hydrops MRI were referred to the EH group. Another 22 patients (22 ears) who tested negative for EH were classified as the non-EH group.

RESULTS

Significant difference in the mean hearing levels between EH and non-EH groups was identified at frequencies of 125, 250, 500, and 1,000 Hz, but not at frequencies ranging from 2,000 Hz through 8,000 Hz. A declining sequence of abnormality rates - from audiometry (96%), cervical vestibular-evoked myogenic potential (cVEMP) test (75%), ocular VEMP test (57%) to the caloric test (43%) - was observed in the EH group but not in the non-EH group. This pattern closely paralleled the decreasing prevalence of EH on hydrops MRI, which moved from the cochlea (79%), saccule (61%), utricle (57%) to the semicircular canals (4%).

CONCLUSION

A comprehensive inner ear test battery aligned with hydrops MRI may enhance understanding of disease mechanisms and aid differential diagnosis in selected ambiguous cases of acute-onset SNHL, whether it arises from EH.