The Influence of Clicks versus Short Tone Bursts on the Vestibular Evoked Myogenic Potentials

In Brief Objective Vestibular evoked myogenic potential (VEMP) has become a diagnostic tool to evaluate the integrity of sacculo-collic reflex. To obtain a more consistent VEMP response in normal-hearing subjects, we examine whether clicks or short tone bursts are more effective in eliciting VEMP responses. Design Prospective study. Twenty-nine normal-hearing volunteers (58 ears) were given VEMP tests. Clicks and short tone bursts were presented alternately to evoke VEMPs. The latencies of peak p13 and n23, peak-to-peak interval and amplitude (p13-n23) were measured and compared. Results Click stimulation of 57 ears (98%) produced VEMPs (C-VEMPs), whereas 51 (88%) revealed positive short tone burst-evoked VEMPs (STB-VEMPs), exhibiting a significant difference (p < 0.05). Furthermore, C-VEMPs displayed shorter latency, longer interval and larger amplitude than STB-VEMPs, with a significant difference (p < 0.05), respectively. Conclusions C-VEMPs had a higher response rate, shorter latency, and larger amplitude than STB-VEMPs. These findings suggest that click is superior to short tone burst to trigger VEMPs. Because C-VEMPs have a shorter p13 latency than STB-VEMPs, the interpretation of prolonged latency differs in each stimulus condition. The vestibular evoked myogenic potential (VEMP) has become a diagnostic tool to evaluate the integrity of the sacculo-collic reflex. VEMPs are typically recorded as electromyographic responses (sternocleidomastoid muscle contractions) to loud acoustic stimuli. These two studies examine different ways of eliciting VEMPs. The first investigates an alternative VEMP elicitation method for patients with chronic otitis media (COM), a condition that may obscure VEMP results due to conductive attenuation of the stimulus, even when the actual physiological response is intact. The study found that VEMPs could more readily be elicited in COM patients when stimuli were delivered by tapping on the forehead with a tendon hammer than when stimuli were delivered acoustically. The second study compared two acoustic methods used to elicit VEMPs. It was found that clicks produced a positive response in 57 out of 58 ears (98%), whereas short tone bursts elicited responses in 51 of those ears (88%).