P 74 Endolymphatic hydrops of the inner ear in patients with vestibular migraine and concurrent Meniere's disease – VOLT algorithm extension

Abstract

Introduction: Delayed intravenous Gadolinium (Gd) enhanced, high-resolution magnetic resonance imaging of the inner ear (iMRI) confirmed that both patients with Menière's disease (MD) and vestibular migraine (VM) can present with endolymphatic hydrops (EH) [1]. VOLT is a recently proposed semi-automatic open-source image analysis pipeline using volumetric local thresholding for iMRI [2]. This study examined the EH characteristics in patients with VM, MD, or VM with concurrent MD (VM-MD) and searched for pathology-specific EH interrelations to neurotologic testing. Methods: We included 62 patients (45 females, aged 25-81y, mean: 56.6y). 25 patients suffered from VM (19 definite VM, 6 probable VM), 29 suffered from MD (17 definite MD, 12 probable MD), while 8 patients presented with VM and concurrent MD (VM-MD). The diagnostic workup included neurotologic assessments (videooculography (VOG) during caloric stimulation & head-impulse-test, ocular & cervical vestibular evoked myogenic potentials, as well as pure tone audiometry) and an iMRI using the HYDROPSMi2-protocol [for details see: 3]. In addition, the EH was assessed using a conventional radiological visual 2D-grading system [4] as well as after 3D quantification using a probabilistic atlas-based [5] segmentation of the bony labyrinth and the VOLT [2] pipeline. Results: EH in VM was observed twice (8%, Fig. 1), while 13 of 25 (52.0%) VM patients reported varying auditory symptoms without EH (cp. Fig. 1A). EH in MD was frequent (23/29, 79.3%, cp. Fig. 1B). Location and laterality of EH and neurophysiological testing classifications were highly associated (Fisher exact test, p < 0.005). In MD, visual semi-quantitative grading and volumetric quantification correlated highly to each other (rS = 0.8, p < 0.005, two-sided) and to side differences in VOG during caloric irrigation (vestibular EH ipsilateral: rS = 0.6, p < 0.05, two-sided). In VM, correlations were less pronounced. VM-MD assumed an intermediate position between VM and MD regarding EH frequency (2/8, 25%, cp. Fig. 1C) and correlation to VOG side differences. Conclusion: (i) The semi -automatic analysis VOLT [2] can be easily applied to HYDROPSMi2 [3] with the assistance of probabilistic atlas [5]. (ii) Cochlear and vestibular hydrops can occur in MD and VM patients with auditory symptoms. EH grades often correlate with auditory symptoms like hearing impairment or tinnitus. Further research is required to uncover whether migraine is one causative factor of EH or whether EH in VM patients with auditory symptoms suggests an additional pathology due to MD [1].