Changes in endolymphatic hydrops after sac surgery examined by Gd-enhanced MRI

Conclusion: Endolymphatic hydrops could be a reversible inner ear pathological condition. After sac surgery, hydrops was reduced and symptoms went into remission in some cases, although vertigo suppression was not always a result of the reduced hydrops. Objective: To examine the changes in endolymphatic hydrops detected by gadolinium (Gd) contrast-enhanced magnetic resonance imaging (MRI) before and 6 months after endolymphatic sac surgery in patients with unilateral Meniere's disease. Methods: Fluid-attenuated inversion recovery MRI was obtained 4 h after intravenous administration or 24 h after intratympanic administration of Gd contrast medium. An enlarged negative stain corresponding to the cochlear duct and endolymphatic space of the vestibule was assessed as hydrops. Results: Of seven patients with hydrops confirmed by MRI before surgery, both cochlear and vestibular hydrops became negative in two, cochlear hydrops became negative in one, both hydrops were present, but reduced, in one, and there was no change in three patients. The number of vertigo spells was reduced in all cases at 6-12 months after surgery. As for the three cases of negative hydrops, vertigo was completely suppressed. In two cases in which hearing level improved, hydrops became negative after surgery.