Vestibular migraine (VM) and Ménière’s disease (MD) could overlap or mimic each other. Since the use of cVEMPs became routine, attempts have been made by researchers to explore its clinical utility in these two conditions. In this prospective study, the authors recruited 22 patients with definite VM and 30 patients with definite MD. They were age-matched with 18 healthy volunteers. cVEMPs were carried out in the quiescent phase and measured in response to 500 Hz and 1000 Hz tone burst stimuli. At these two frequencies, the p13/n23 latencies, peak-to-peak amplitude and frequency ratio (FR, the amplitude at 1000 Hz divided by amplitude at 500 Hz) were compared between VM and MD subjects (affected and unaffected ears) and asymmetry ratio (AR) compared for all three groups. There were no significant differences in latencies between the study groups. The mean peak-to-peak amplitude at 500 Hz was significantly lower in MD affected ears compared with MD unaffected ears and controls (p = 0.003 and p = 0.001, respectively) but not with VM. However compared with healthy controls, the peak amplitude was lower in the VM subjects. The FR (1000 Hz/500 Hz) was larger in MD affected ears compared with unaffected ears and the other groups as well as a high asymmetry ratio (AR) at 500 Hz. The cVEMP parameters that differentiated MD from VM were higher AR at 500 Hz and larger FR in MD.
Of note, peak-peak amplitude was reduced in VM compared to controls suggesting some degree of ischaemia in the otolith organs in VM. When confronted with the diagnostic conundrum: VM or MD, try cVEMPs!
