3T-3D FLAIR MRI in Menière's disease: associated profiles with clinical symptoms and electroacoustic characteristics

Abstract

Purpose: Diagnosis of Menière's disease relies on clinical symptoms. Injected 3T MRI can show endolymphatic hydrops (EH), but correlation with the clinical status of MD, (probable -PMD or definite-DMD) remains doubtful. We revealed endolymphatic pressure disruption through functional exploration and verified if it was associated with an EH through MRI.

Materials and methods: We prospectively analyzed 3D3T FLAIR MRI of DMD and PMD patients. All of them underwent electrocochleography (EcoG), distortion-product otoacoustic emissions (DPOAEs), and videonystagmograhy (VNG). Amplitudes of summating potential (SP) and cochlear nerve action potential (AP) were measured on EcoG. DPOAE-phase was collected at 1 kHz for the 2f1-f2 DPOAE between sitting and laying position. A SP/AP ≥ 40% and a DPOAE phase-shift > 40° revealed pressure disruption.

Results: 39 patients (25 women, 53 y.o. 20-78), were included, with 32 DMD ears and 11 PMD ears. MRI was performed in a median of 21 days [0; 68] from the MD incident. Audiovestibular exploration took place 41 days after the crisis [0;83]. MRI revealed an EH in 71.9% and 27.2% of DMD and PMD, respectively. When combining functional explorations and MRI, testing was positive in 97% for DMD and 82% for PMD. When abnormal (59%), VNG mainly showed hyporeflexia in the diseased ear.

Conclusion: In patients suffering from DMD or PMD, with endolymphatic pressure disturbances confirmed by combined DPOAE-phase and EcoG, 3T 3D MRI reveals EH mostly in DMD but rarely in PMD. This seems to confirm that disturbance of endolymphatic pressure precedes EH.

Keywords: 3D3T-MRI; Distortion-product otoacoustic emissions; Electrocochleography; Hydrops; Meniére’s disease.

Fig. 1

Electrocochleography (EcoG): Graph figuring amplitude of EcoG signal (microvolt, 0.25 microV/division) against time (ms) in response to sound stimulation by clicks at 80 dB HL. The summating potential (SP) is identified around 0.8 ms and the compound action potential (AP) around 1.2–1.5 ms. LEFT: normal tracing; RIGHT: pathological tracing compatible with hydrops with SP/AP > 40%

Fig. 2

Acoustic phase shift as seen through cubic DPOAE recording at 2F1-F2, at 1.2 kHz (with F2/F1 = 1.2) in sitting and laying position. Red area: noise floor; Green area: DPOAE intensity in dB SPL (right ordinate); red closed circles and red solid line: DPOAE phase (°) in sitting position; green closed circles and green solid line: DPOAE phase (°) in laying position; Blue dotted lines: average (“moyenne”) of DPOAE phase in the two positions. 1A: no significant acoustic phase shift. 2B: significant acoustic phase shift compatible with a labyrinthine pressure disruption (77° in sitting position vs. 139° in laying position that is, a 62°-DPOAE-phase shift)

Fig. 3

3T MRI Axial views (3DFLAIR sequences), 4 h after intra veinous Gadolinium in a 39 years old patient with definite left Meniere Disease. Note the left saccular and utricular hydrops grade 2 while the right saccule and utricule are normal (white arrowheads points to saccules, white dotted arrows points to utricules). There was also a cochlear hydrops grade 2 on the left side (black arrows)