Single motor unit responses underlying cervical vestibular evoked myogenic potentials produced by bone-conducted stimuli

Splenius capitis is a reliable target for measuring cervical vestibular evoked myogenic potentials in adults

“…IM recordings confirm that the p13 and n23 responses relate to a reduction and subsequent rebound of SCM activity, respectively (Colebatch & Rothwell, ). A small transient excitation preceding the p13 response has also been reported in some cases (Rosengren et al ., ). We observed many of these same features during IM SPL recordings, with inhibition of SPL motor unit activity being the most consistent feature.…”

“…All subjects tolerated the presented stimulus without reporting pain or discomfort. Subject 2 reported a transient period (2 h) of tinnitus in one ear immediately following testing despite stimulus intensity calibrated to levels commonly used in the literature (Weber et al, 2012;Colebatch & Rosengren, 2014;Rosengren, 2015;Rosengren et al, 2015). In this subject, sound was delivered to the affected ear for nine 1-minute files, delivering a total of 3987 tone bursts (15.9 s of sound in total) to the affected ear.…”

“…Recent work by Rosengren et al . () showed that the amplitude of the SCM cVEMP scales linearly as a function of background muscle EMG activity. We confirmed this in our study for the SCM cVEMP in all postures, and also found a similar linear scaling for SPL.…”

The evidence is finally here: Ocular vestibular evoked myogenic potentials are mainly dependent on utricular pathway function

“…This has also been shown in a previous editorial (Papathanasiou, 2014), in comments on research by the same group with respect to the same impulsive lateral acceleration (Rosengren et al, 2014). This stimulus was believed previously to act by the bilateral outward movement of the skull on each side, and was expected to stimulate the utricle predominantly.…”

The polarity of the cervical vestibular evoked myogenic potential, and how it helps us further understand the vestibulo-collic pathway

“…The need to do research with invasive recordings to confirm the above models was inevitable, and it is therefore welcoming that such a study has been done with regards to cVEMPs and is presented in this issue (Rosengren et al, 2015). An earlier study also recorded from single motor units invasively, using air-conducted (AC) clicks and galvanic stimulation (Colebatch and Rothwell, 2004), but this more recent study also includes bone-conducted (BC) stimuli.…”