Vestibular-evoked myogenic potentials.

PURPOSE OF REVIEW This article reviews the literature on vestibular-evoked myogenic potential testing, a short latency electromyogram evoked by high acoustic stimuli and recorded via surface electrodes over the sternocleidomastoid muscle. Applications and refinements of this technique are described for different pathologies and in adults and children. RECENT FINDINGS Various techniques for electrode placement have been described to elicit a vestibular-evoked myogenic potential response, which has been clinically investigated in normal individuals, under pathological conditions, and in adult and pediatric patients. As vestibular-evoked myogenic potential amplitude is linearly related to the level of background activity of the sternocleidomstoid muscle, maintaining steady contraction of the muscle can be challenging in some patients. SUMMARY Vestibular-evoked myogenic potential testing may provide additional information about the vestibular system and allow site of lesion testing (e.g. saccule and inferior vestibular nerve) in patients of all ages. Its role has yet to be defined in the diagnosis and treatment of common vestibular disorders, including Meniere's disease, vestibular neuronitis, labyrinthitis, and other diseases. Further research is needed to support its clinical usefulness in patients with balance disorders, to optimize patient selection, and to establish its cost effectiveness.