Relationship Between Audio-Vestibular Functional Tests and Inner Ear MRI in Meniere's Disease

Meniere's disease is an inner ear disorder generally attributed to an endolymphatic hydrops. Different electrophysiological tests and imaging techniques have been developed to improve endolymphatic hydrops diagnosis. The goal of our study was to compare the sensitivity and the specificity of delayed inner ear magnetic resonance imaging (MRI) after intravenous injection of gadolinium with extratympanic clicks electrocochleography (EcochG), phase shift of distortion product otoacoustic emissions (shift-DPOAEs), and cervical vestibular-evoked myogenic potentials (cVEMP) for the diagnosis of Meniere's disease.

Forty-one patients, with a total of 50 affected ears, were included prospectively from April 2015 to April 2016 in our institution. Patients included had definite or possible Meniere's disease based on the latest American Academy of Otolaryngology-Head and Neck Surgery guidelines revised in 2015. All patients went through delayed inner ear MRI after intravenous injection of gadolinium (three dimension-fluid attenuated inversion recovery sequences), pure-tone audiometry, extratympanic clicks EcochG, shift-DPOAEs, and cVEMP on the same day. Endolymphatic hydrops was graded on MRI using the saccule to utricle ratio inversion defined as when the saccule appeared equal or larger than the utricle.

Abnormal EcochG and shift-DPOAEs in patients with definite Meniere's disease (DMD) were found in 68 and 64.5%, respectively. The two methods were significantly associated in DMD group. In DMD group, 25.7% had a positive MRI. The correlation between MRI versus EcochG and MRI versus shift-DPOAEs was not significant. MRI hydrops detection was correlated with hearing loss. Finally, 22.9% of DMD group had positive cVEMP.

EcochG and shift-DPOAEs were both well correlated with clinical criteria of Meniere's disease. Inner ear MRI showed hydrops when hearing loss was higher than 35 dB. The shift-DPOAEs presented the advantage of a rapid and easy measurement if DPOAEs could be recorded (i.e., hearing threshold <60dB). In contrast, EcochG can be performed regardless of hearing loss. In combination with shift-DPOAEs, it enhances the chances to confirm the diagnosis with a better confidence.