Non-epileptic seizures in autonomic dysfunction as the initial symptom of COVID-19

Objective!#!Vestibular evoked myogenic potentials (VEMPs) have been suggested as biomarkers in the differential diagnosis of Menière's disease (MD) and vestibular migraine (VM). The aim of this study was to compare the degree of asymmetry for ocular (o) and cervical (c) VEMPs in large cohorts of patients with MD and VM and to follow up the responses.!##!Study design!#!Retrospective study in an interdisciplinary tertiary center for vertigo and balance disorders.!##!Methods!#!cVEMPs to air-conducted sound and oVEMPs to bone-conducted vibration were recorded in 100 patients with VM and unilateral MD, respectively. Outcome parameters were asymmetry ratios (ARs) of oVEMP n10p15 and cVEMP p13n23 amplitudes, and of the respective latencies (mean ± SD).!##!Results!#!The AR of cVEMP p13n23 amplitudes was significantly higher for MD (0.43 ± 0.34) than for VM (0.26 ± 0.24; adjusted p = 0.0002). MD-but not VM-patients displayed a higher AR for cVEMP than for oVEMP amplitudes (MD 0.43 ± 0.34 versus 0.23 ± 0.22, p < 0.0001; VM 0.26 ± 0.14 versus 0.19 ± 0.15, p = 0.11). Monitoring of VEMPs in single patients indicated stable or fluctuating amplitude ARs in VM, while ARs in MD appeared to increase or remain stable over time. No differences were observed for latency ARs between MD and VM.!##!Conclusions!#!These results are in line with (1) a more common saccular than utricular dysfunction in MD and (2) a more permanent loss of otolith function in MD versus VM. The different patterns of o- and cVEMP responses, in particular their longitudinal assessment, might add to the differential diagnosis between MD and VM