Abstract
The author showed variants of the vestibular evoked myogenic potential (VEMP), which have been developed as a myogenic potential evoked on the sternocleidomastoid muscle by air-conducted sound (ACS). The prototype of the VEMP is called the ACS cVEMP (cervical VEMP). Firstly, the author introduced VEMP by bone-conducted vibration (BCV). While ACS VEMP is not applicable to subjects with conductive hearing loss, BCV VEMP can be recorded even in such subjects. Examiners of BCV VEMP should bear in mind that BCV can stimulate wider areas in the vestibular labyrinth than ACS. Secondly, the author described VEMPs recorded using electrodes placed beneath the lower eye lids, which is called oVEMP. While cVEMP is recordable in the SCM ipsilateral to the stimulated ear, oVEMP is clearly recorded in the electrodes beneath the lower eyelid contralateral to the stimulated ear. oVEMP is promising as a new test of vestibulo-ocular reflexes, especially otolith-ocular reflexes. The author also emphasizes that further studies to identify the vestibular end-organs and extra-ocular muscles which participate in formation of oVEMP responses and the neural pathway of oVEMP are required.
