Synergistic role of blood-labyrinth barrier permeability and endolymphatic hydrops: a comparative perspective in Ménière's disease and vestibular migraine.

Objective: This study compares the delayed gadolinium-enhanced MRI characteristics of Ménière's disease (MD) and vestibular migraine (VM) to develop a multiparametric model that incorporates endolymphatic hydrops (EH), blood-labyrinth barrier permeability, and their asymmetry. Additionally, it investigates the correlations between these imaging features and hearing loss across various frequencies. Methods: A total of 79 patients-47 with MD and 32 with VM-were enrolled in the study between June 2023 and April 2025. All participants underwent a comprehensive medical history assessment, neurotologic evaluation, audiological testing, and a 3D SPACE FLAIR MRI conducted 4 h after the administration of intravenous gadolinium contrast agents. EH, the signal intensity ratio (SIR) of the cochlear basal turn, and the cochlear SIR asymmetry index (c-SIR AI) were assessed. Linear regression was employed to evaluate the contributions of EH and SIR to hearing loss. Additionally, a logistic regression model with ROC analysis was developed for diagnostic purposes. Results: All ipsilateral ears in the MD group exhibited EH, with median cochlear and vestibular EH grades of 2 (1, 2) and 1 (1, 2), respectively. These grades were significantly higher than those observed in the VM group, where the median grades were 0 (0, 1) for both cochlear and vestibular EH (both Conclusion: Delayed gadolinium-enhanced MRI of the inner ear facilitates the differentiation between MD and VM. The combination of EH, SIR, and c-SIR AI demonstrates excellent diagnostic performance. Notably, elevated SIR shows the strongest correlation with high-frequency hearing impairment, while cochlear EH primarily contributes to low- and mid-frequency hearing loss. By integrating imaging findings with audiological profiles, clinicians can accurately characterize cochlear pathology, enabling the development of tailored treatment strategies.