Endolymphatic hydrops revealed by magnetic resonance imaging in patients with acute low-tone sensorineural hearing loss

Objective: Acute low-tone sensorineural hearing loss (ALHL) has been reported to be associated with endolymphatic hydrops (EHs). However, evaluation of the size of the endolymphatic space has not been reported. We attempted to visualize EH in ALHL using magnetic resonance imaging (MRI). Study Design: Prospective diagnostic study. Setting: University hospital. Methods: We evaluated 25 ears of 25 unilateral ALHL patients. Three-tesla MRI was obtained 24 hours after intratympanic injection of gadolinium (Gd) (n = 5) or 4 hours after intravenous injection of Gd (n = 20). A radiologist blinded to the patients' clinical data classified the degree of EH in the vestibule and cochlea into 3 groups: none, mild, and significant. Results: On the affected sides, cochlear EH was recognized in 23 ears (92%) and was classified as significant EH (n = 15) or mild EH (n = 8); vestibular EH was detected in 22 ears (88%), classified as significant EH (n = 16) or mild EH (n = 6). Cochlear EH was more frequently observed in the affected ear than in the contralateral ear (90% versus 40%, p < 0.05). Conclusion: In ALHL, EH was observed not only in the cochlea but also in the vestibule as in Ménière's disease.