Does Endolymphatic Hydrops Influences Gentamicin Effects in Meniere Disease Patients Undergoing Intratympanic...

To investigate whether the severity of endolymphatic hydrops (EH) influences the audiovestibular effects of intratympanic gentamicin (ITG) in patients with unilateral Ménière disease (uMD).

Forty patients in 2 different tertiary referral centers with uMD refractory to medical treatment underwent 3T MRI 4 hours after gadolinium administration. EH severity was evaluated qualitatively and quantitatively (volumetry). Audiovestibular function was assessed with the PTA, vHIT, cVEMP, and oVEMP before and 1 month after ITG. Associations were analyzed with Kruskal-Wallis tests, Pearson/Spearman correlations, and logistic regression models.

After ITG, a significant vestibulo-ocular reflex gain reduction was observed in the horizontal (ΔGain: 30.72%) and posterior (ΔGain: 34.64%,) semicircular canals, while hearing showed nonsignificant minimal increase (ΔPTA: 5.88 dB). cVEMP responses were more frequently absent ( P = 0.018), and the IAAR increased significantly ( P = 0.003). The level of EH and its amount, as measured by the relative volume in the vestibule ( v ELRaff), both with perilymphatic enhancement, were all positively correlated with the amount of vestibular damage in both PSC and HSC; however, did not correlate with changes in PTA ( P = 0.266). In contrast, cochlear EH showed no predictive value for posttreatment hearing loss. Endolymphatic herniation was significantly associated with cVEMP changes ( P = 0.016).

EH does not act as a barrier to gentamicin diffusion. MRI-based EH assessment may help predict treatment outcomes and guide safer ITG strategies.