How is the vestibular evoked myogenic potentials test (VEMPs) performed in a dizziness evaluation?

Updated: Jun 26, 2018
  • Author: Wayne T Shaia, MD; Chief Editor: Arlen D Meyers, MD, MBA  more...
  • Print
Answer

Answer

Vestibular evoked myogenic potentials

  • A test of the patient's vestibular evoked myogenic potentials (VEMPs) can help determine the neural integrity of the saccule and inferior vestibular nerve. The saccule, which has some sound sensitivity, is innervated by means of the inferior vestibular nerve. The inferior vestibular nerve has its main input to the lateral vestibular nucleus (Deiter nucleus), where the 2 main postural tracts originate. The medial vestibulospinal tract is responsible for postural control of the neck, whereas the lateral vestibulospinal tract is dedicated to the lower trunk and limbs. For the most part, sound-evoked VEMPs are considered completely unilateral.

  • The test is performed simply by placing EMG electrodes on the anterior neck muscles including the sternocleidomastoid muscle. The patient holds their head up unsupported, using only their anterior neck muscles. The patient is instructed to tense the muscle during acoustic stimulation, and relax after the stimulation stops. Loud clicks or tone bursts (95-100 DB nHL) are repetitively presented to each ear. If the neck muscles are not activated, no VEMP is produced.

  • This technology is currently still evolving, and its clinical utility is still being determined. The technology is currently being applied to patients with suspected Ménière disease when the diagnosis is unclear. More recently, it has been applied to patients with superior canal dehiscence and vestibular schwannomas.

  • Recent studies have demonstrated that surface electrodes placed near the eyes can record VEMPs from the extraocular muscles (known as ocular VEMPs). [1] More research is needed to determine the clinical value of these measurements.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!