Effect of Stimulus Rise-Time on the Ocular Vestibular-Evoked Myogenic Potential to Bone-Conducted Vibration

Abstract

In summary, in this sample of healthy subjects, the most effective stimulus for eliciting oVEMP n10 to BCV at Fz was found to be a tone burst with a rise-time of 0 msec at low stimulus frequency (250 or 500 Hz).

Vestibular evoked myogenic potentials in practice: Methods, pitfalls and clinical applications

“…The otolith organs may be sensitive to changes in acceleration over time (Curthoys et al, 2006, Jones et al, 2011) and thus VEMPs are larger and peak earlier if the onset of a stimulus (i.e. rise time) is short (Cheng and Murofushi, 2001b, Burgess et al, 2013). In fact, stimulus rise time is one of the major factors determining reflex latency and for this reason it is important to collect normal data for each stimulus.…”

Letter to the Editor

“…To the Editor: Burgess et al (2013) have reported new data on the effects of rise time and stimulus frequency on the ocular vestibular evoked myogenic potential (OVEMP) evoked by skull vibration. In contrast to previous reports, they found a broad tuning curve with no clear best frequency.…”

“…Neither was the amplitude of the induced acceleration measured for different frequencies (cf. The methodological approach of Burgess et al (2013) means the tuning properties of the OVEMP they showed with vibration are likely to be confounded by the idiosyncrasies of both their stimulus manipulations and their subjects' tolerance of different stimulus intensities. The use of individual subjective comfort criteria would certainly produce a nonconstant peak acceleration profile across frequency.…”

“…Stimulus application at the forehead, as recommended by Burgess et al (2013), has other limitations. Because the line of force does not pass through the center of mass of the head, stimulation at the forehead gives rise to pitching of the head, due to a turning moment being produced (unpublished observations).…”

“…Because the line of force does not pass through the center of mass of the head, stimulation at the forehead gives rise to pitching of the head, due to a turning moment being produced (unpublished observations). Saccular afferents characteristically respond to vertical LETTERS TO THE EdITOR accelerations (e.g., Jamali et al 2009) and contributions from both utricular and saccular afferents may also explain the broad tuning curves reported by Burgess et al (2013). Forehead stimulation produces an unnatural mastoid motion where the two halves of the skull move in opposite directions (Iwasaki et al 2008).…”