Morphometric Evaluation of Facial and Vestibulocochlear Nerves Using Magnetic Resonance Imaging in Patients with Menière’s Disease

Several studies proposed a loss of neural structures (such as hair cells or neurons within the spiral ganglion) in Menière’s disease (MD). It has been shown that VIIth and VIIIth cranial nerves are enlarged within MD patients compared to normal controls. We now aimed to investigate potential differences in these two nerves in patients with MD. Etiology of endolymphatic hydrops, central pathological hallmark of MD, includes genetic predisposition, autoimmune processes, viral infections, cellular apoptosis and oxidative stress. We evaluated morphometric properties (long and short diameter, cross-sectional area) of the VIIth and VIIIth cranial nerves passing from the cerebellopontine angle to the inner ear modiolus, acquired on a clinical 3T magnetic resonance imaging scanner. 71 patients with MD were included, 53 of whom clinically showed a unilateral affection. Our data showed no differences in nerve morphometry between the clinically non-affected and the clinically affected side in patients with clinically unilateral MD. There was also no correlation to duration of symptoms, in contrast to previously demonstrated correlations between clinical features and the extent of endolymphatic hydrops. A disease process starting before the onset of clinical symptoms could be a potential explanation.