The etiologies of hearing loss in Meniere’s disease：Impairment of internal auditory canal barrier

Objective : The aim of this investigation was to explore the potential correlation between signal intensity ratio (SIR) at internal auditory canal (IAC) bottom and hearing impairment in MD, thereby providing a foundation for further comprehension of the underlying mechanisms contributing to hearing loss. Design : Fifty patients diagnosed with unilateral definited MD were enrolled in the study. 3D-FLAIR MRI was conducted four hours after intravenous administration of gadobutrol to determine the SIR of bilateral IAC bottom. The difference of SIR of IAC bottom was assessed between affected and unaffected sides, followed by an analysis of its correlation with low-, middle-, and high-tone hearing thresholds. Additionally, correlation analysis was conducted between the degree of EH in vestibular and cochlea and the SIR on the affected side. Results: The degree of EH in MD can be clearly visualized through 3D-FLAIR MRI. The SIR on the affected side was significantly higher than that on the unaffected side (P=0.000). Furthermore, a positive correlation was observed between the SIR at the affected and low (r=0.692, P=0.000), middle (r=0.615, P=0.000) and high-tone (r=0.440, P=0.001); the SIR showed no significant correlation with cochlear (r=0.315, P=0.088) or vestibular hydrops (r=0.215, P=0.244). Conclusion : 3D-FLAIR MRI can observe the degree of EH in MD; impairment of the internal auditory barrier may be one of the factors of hearing loss in MD.