Volume ratio and distribution rate in patients with orthostatic vertigo/dizziness using MR imaging: a comparison with vertiginous diseases

BACKGROUND

Orthostatic dizziness/vertigo (ODV) is characterized by lightheadedness owing to postural changes.

AIMS/OBJECTIVES

To measure the endolymphatic space (ELS)/total fluid space (TFS) volume ratio and the distribution rate of endolymphatic fluid (ELF) of patients with ODV and compare them with those of control subjects (CS).

MATERIALS AND METHODS

This study included 22 patients (44 ears) with ODV and 52 controls (104 ears, CS). The ELS/TFS volume ratio (%) and distribution rate (%) of the inner ear components were measured using 3-dimensional magnetic resonance imaging.

RESULTS

In the ODV group, the mean ELS/TFS volume ratios of the cochlea, vestibule, and semi-circular canals (SCCs) were 12.1%, 18.6%, and 18.1%, respectively; the mean ELS distribution rates for the cochlea, vestibule, and SCCs were 27.3%, 26.2%, and 46.6%, respectively. The ELS distribution rate of the vestibule was significantly lower (p < .01) and the ELS distribution rate of the SCCs was significantly higher in the ODV than in the CS group (p < .01).

CONCLUSIONS AND SIGNIFICANCE

The ELS distribution rate in the vestibule + SCCs among patients with ODV did not differ from that in the CS; ELF in the vestibule moved to the SCCs, and a large amount of ELF was distributed only in the SCCs.

Evaluation of changes in endolymphatic volume after middle ear pressure therapy for intractable meniere's disease using 3D magnetic resonance imaging

BACKGROUND

Nowadays, the endolymphatic space size can be evaluated by 3D-analysis of 3 T-MRI after intravenous injection of gadolinium enhancement.

AIMS/OBJECTIVES

In the present study, to elucidate the relationships between vertigo and endolymphatic hydrops (EH) volume after middle ear pressure therapy (MEPT), we investigated changes in EH volume after MEPT for intractable Meniere's disease (MD) by means of the inner ear MRI (ieMRI) in relation to clinical results.

MATERIALS AND METHODS

We enrolled 202 successive definite MD cases with intractable vertiginous symptoms from 2015 to 2020, assigning Group-I of MEPT, and Group-II of endolymphatic sac drainage (ELSD). Ninety patients completed the planned 2-year-follow-up, which included assessment of vertigo frequency and changes in EH volume using ieMRI (Group-I/MEPT: n = 40; Group-II/ELSD: n = 50).

RESULTS

Two years after surgery, vertigo was completely controlled in 77.5% of patients in Group-I and 90.0% in Group-II. Hearing improved by >10 dB in 7.5% of patients in Group-I and 24.0% in Group-II. ELS ratios were significantly reduced after treatments of Group-I and Group-II only in the vestibule.

CONCLUSIONS

The obtained results indicate that MEPT as well as ELSD could be a good treatment option for patients with intractable MD.

Case Report: Filling Defect in Posterior Semicircular Canal on MRI With Balanced Steady-State Gradient-Echo Sequences After Labyrinthine Ischemia in the Common Cochlear Artery Territory as an Early Sign of Fibrosis

We describe a rare case of posterior semicircular canal (PSC) fibrosis following acute labyrinthine ischemia in the territory supplied by the common cochlear artery (CCA) and review the relevant literature. A 71-year-old man with multiple vascular risk factors presented 12 days after the onset of acute vertigo and profound left-sided hearing loss. Right-beating spontaneous nystagmus with downbeat components elicited by mastoid vibrations and headshaking was detected. The video head impulse test (vHIT) revealed an isolated hypofunction of the left PSC, whereas vestibular evoked myogenic potentials (VEMPs) showed ipsilateral saccular loss. The clinical presentation and instrumental picture were consistent with acute ischemia in the territory supplied by left CCA. Compared to previous imaging, a new MRI of the brain with 3D-FIESTA sequences highlighted a filling defect in the left PSC, consistent with fibrosis. Hearing function exhibited mild improvement after steroid therapy and hyperbaric oxygen sessions, whereas vHIT abnormalities persisted over time. To the best of our knowledge, this is the only case in the literature reporting a filling defect on MRI, consistent with semicircular canal fibrosis following acute labyrinthine ischemia. Moreover, PSC fibrosis was related with poor functional outcome. We therefore suggest using balanced steady-state gradient-echo sequences a few weeks following an acute lesion of inner ear sensors to detect signal loss within membranous labyrinth consistent with post-ischemic fibrosis. Besides addressing the underlying etiology, signal loss might also offer clues on the functional behavior of the involved sensor over time. In cases of acute loss of inner ear function, a careful bedside examination supplemented by instrumental assessments, including vHIT and VEMPs, of vestibular receptors and afferents may be completed by MRI with balanced steady-state gradient-echo sequences at a later time to confirm the diagnosis and address both etiology and functional outcome.