1. Introduction
Menière’s disease (MD) is characterized by episodic vertigo associated with tinnitus, fluctuating hearing loss, aural fullness and endolymphatic hydrops (ELH) (1, 2). Several studies proposed a loss of neural structures (such as hair cells or neurons within the spiral ganglion) in Menière’s disease (MD) (3). In recent years several studies have evaluated and quantified ELH in patients with MD (4). Only few studies, however, have analyzed morphometric parameters of cranial nerves VII and VIII on MRI (5-8).
The course of cranial nerves VII and VIII from the pons through the cerebellopontine angle and the internal auditory canal (9) make these nerves amenable to morphometric evaluation in anatomical and MRI studies. The VIIIth cranial nerve divides within the IAC into its three branches: cochlear nerve (CN), superior vestibular nerve (SVN) and inferior vestibular nerve (IVN). In the anterosuperior portion of the IAC the facial nerve is found, and inferior to it the cochlear nerve (10). To our knowledge, no morphometric analyses of these nerves have been performed using different MRI sequences with different spatial resolution in patients with clinically unilateral MD in correlation to symptom duration.
We previously demonstrated a swelling of VIIth and VIIIth cranial nerves on MR imaging in patients with MD (8). The aim of this study was to investigate morphometric differences of the VIIth and VIIIth cranial nerve within MD patients using different MR imaging techniques.