Endolymphatic hydrops detected by 3-dimensional fluid-attenuated inversion recovery MRI following intratympanic injection of gadolinium in the asymptomatic contralateral ears of patients with unilateral Ménière's disease

Abstract

Background: The aim of this study was to identify the incidence of endolymphatic hydrops using 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging (MRI) in the contralateral ear in patients with unilateral Ménière's disease (MD).

Material and methods: This was a prospective study. 3D-FLAIR MRI was performed with a 3 Tesla (3 T) unit 24 h after the intratympanic administration of gadolinium (Gd) in 30 unilateral MD patients with an asymptomatic contralateral ear. The incidence of contralateral involvement in unilateral MD patients and the potential correlations between the affected and contralateral ears were analyzed.

Results: Endolymphatic hydrops was observed in 7 of the 30 (23.3%) asymptomatic ears. The mean PTA of the asymptomatic ears in the contralateral hydrops patients (33.0±6.1 dB) was significantly higher compared with the non-hydrops patients (17.8±5.7 dB). The patients with observed contralateral hydrops exhibited a significantly longer duration of the disease compared with the non-hydrops patients (6.7±6.3 vs. 2.9±3.1 years, respectively). Furthermore, the patients with contralateral hydrops had a worse hearing level in the affected ears compared with the non-hydrops patients (70.3±7.4 vs. 52.5±3.8 dB, respectively).

Conclusions: Endolymphatic hydrops is closely related to hearing loss but does not necessarily result in Ménière's symptoms. Patients with a long history of MD and severe hearing loss in the affected ear are more likely to exhibit endolymphatic hydrops in the asymptomatic contralateral ear. Adequate attention should focus on unilateral MD patients with contralateral ear hydrops because of the potential to develop bilateral MD.

Figure 1

3D-FLAIR MRI and 3D-FIESTA MRI of patient no. 2. (A – a–e) Five consecutive 3D-FLAIR image of patient no. 2. Arrow with letter c represents cochlear. Arrow with letter v represents vestibule. The vestibular part of the perilymph is not enhanced by the contrast agent in the right affected side. The basal and middle turns of the cochlea are partially enhanced. Severe hydrops in the vestibule and mild hydrops in the cochlea can be observed on the left side, which indicates that the “asymptomatic” ear is involved. (B – a–e) Five consecutive 3-dimensional Fast Imaging Employing Steady-State Acquisition (3D-FIESTA) image of the same patients, which indicates a normal inner ear structure.

Figure 2

MIP of 3D-FLAIR MRI of patient no. 20. Maximum Intensity Projection (MIP) of original 3D-FLAIR images. The vestibular part of the perilymph is partially enhanced by contrast agent in the right affected side. The cochlea showed no hydrops. Mild hydrops in the vestibular and cochlea can be observed on the left side, which indicates the “asymptomatic” ear is involved.