Vestibular evoked myogenic potentials: history and overview.

Vestibular evoked myogenic potential (VEMP) testing is a relatively new diagnostic tool that is in the process of being investigated in patients with specific vestibular disorders. In this review, we will outline the history and provide a current review of VEMP research. Briefly, the VEMP is a biphasic response elicited by loud clicks or tone bursts recorded from the tonically contracted sternocleidomastoid muscle. Current data suggest that the VEMP is a vestibulo-collic reflex whose afferent limb arises from acoustically sensitive cells in the saccule, with signals conducted via the inferior vestibular nerve. We will review the history of the response and detail the anatomy and physiology associated with the test. We will discuss specific VEMP applications in the diagnosis of Meniere's disease, vestibular schwannoma, vestibular hypersensitivity disorders, vestibular neuritis, multiple sclerosis, and other brainstem lesions.