Morphometric evaluation of facial and vestibulocochlear nerves using magnetic resonance imaging in patients with Menière's disease.

Background And Purpose: Menière's disease (MD) is a condition of unknown etiology, involving genetic predisposition, autoimmune processes, viral infections, cellular apoptosis, and oxidative stress. This study aimed to investigate potential differences in the VII and VIII cranial nerves in MD patients using Hydrops-MRI (FLAIR) for morphometric evaluations.

Materials And Methods: Using a 3T MRI scanner, constructive-interference-in-steady-state (CISS) and 3D-FLAIR-inversionrecovery (FLAIR) sequences were acquired. We evaluated the morphometrics of the VII and VIII cranial nerves from the cerebellopontine angle to the internal auditory canal fundus, comparing the non-affected and affected sides. Furthermore, we examined the findings in relation to symptom duration and evaluated feasibility of FLAIR-imaging in morphometry of cranial nerves.

Results: A total of 53 MD patients with unilateral symptoms were included. After statistical analysis, no significant differences were found regarding morphometric changes in the affected side compared to the non-affected side of the VII and VIII cranial nerves. There was also no significant difference between morphometric evaluations of patients with different symptom durations. The morphometric evaluation using Hydrops-MRI-Sequences (FLAIR) showed no significant difference compared to established morphometric highly T2-weighted imaging (CISS).

Conclusions: Our data found no differences in nerve morphometry between clinically non-affected and affected sides in unilateral MD patients, nor any correlation with symptom duration. This contrasts with previous findings of correlations between clinical features and endolymphatic hydrops. A disease process starting before clinical symptom onset could be a possible explanation. Morphometric evaluation of brain nerves using Hydrops-MRI-Sequences is practical and provides similar results to T2-weighted imaging, improving patient comfort and reducing MRI scan time.

Abbreviations: CN = cochlear nerve; CPA = cerebellopontine angle; CSA = cross-sectional area; FN = facial nerve; IAC = internal auditory canal; IVN = inferior vestibular nerve; LD = long diameter; MD = Menière's disease; SD = short diameter; SVN = superior vestibular nerve.