The more I hear / read about VEMPs, the more I want to try testing in the clinical environment.

Mention of the Saccule as the organ of hearing in lower animals (a particular interest of mine in its association with the evolution of vertebrate auditory mechanisms). Innervation of the labyrinth – Superior Vestibular nerve to the Urticle and Horizontal and Lateral SemiCircular Canals, Inferior Vestibular nerve to the Saccule and Inferior SemiCircular Canal.

VEMP based on the principal that a loud acoustic stimulus will generate a large inhibitory response in a tonically active ipsilateral SternoCleidoMastoid Muscle.

Larger than usual response may be obtained in a Fistula or Superior Canal Dihescence (as these act as third windows allowing pressure wave to propagate into the vestibule in addition to along the Cochlear Duct). I wonder whether an enlarged vestibular aqueduct would cause the same effect. May also be used in monitoring during labyrinthectomy. Response is usually absent in Conductive and Menieres

A brief mention of the oVEMP which is an excitatory, rather than inhibitory, response. Todd et al (2007) report that Whilst the AC stimulus generates a response through the Saccule, the BC stimulus generates a response through the Utricle. This I found interesting in follow up to some other stuff I was reading about Enlarged Vestibular Aqueducts, and the difference in sensitivity between AC and BC stimuli. Will need some further investigation…

Reference

Todd, N., Rosengren, S., Aw, S., & Colebatch, J. (2007). Ocular vestibular evoked myogenic potentials (ovemps) produced by air- and bone-conducted sound. Clinical Neurophysiology,

Advertisements