Gümüş began speaking "The test, which was originally used in clinical practice by Colebatch and Halmagyi in 1992, has now become a standard test in vestibular system evaluation." VEMPs are electromyographic responses in muscles that occur in response to sound stimulation. Following identification, it was discovered that vestibular afferents influence multiple muscle groups via the vestibular nucleus. However, the VEMPs acquired from the muscles behind the eyes and the sternocleidomastoid (SCM) muscle in the neck are the most commonly used and measured in the clinic. Despite the fact that the warning patterns of both systems are similar, the responses obtained are of a different nature. "
Then he talked about Cervical VEMP (c-VEMP) and Ocular VEMP (o-VEMP) tests.
"Cervical VEMP (c-VEMP) can be conducted as a routine test for anyone who requires vestibular function evaluation." However, there are certain challenges. It may be difficult to elicit a response from patients who are unable to participate in the test and produce sufficient SCM contraction. It should be noted that obtaining a response in patients with an air-bone gap may be challenging, especially if stimulation is supplied through airway conduction.
“Ocular VEMP (o-VEMP) was first defined in 2003 with 500 Hz bone conduction stimulation and in 2007 with airway stimulation. Unlike c-VEMP, the short latency negative wave is named n10 and is followed by a positive n15. The initial negative peak response is dependent on muscle excitation, unlike c-VEMP. The response is generated by the inferior oblique and inferior rectus muscles. The best o-VEMP response is found in the upward gaze posture and under the eye on the opposite side of the stimulated ear. This is due to the vestibulo-ocular reflex causing these potentials. The reflex starts from the stimuli-activated vestibular nerve and vestibular nucleus complex to the oculomotor nucleus, oculomotor nerve, and extraocular muscles through the medial longitudinal fascicle.” he said.
"O-VEMPs can be recorded under the eye on the stimulated ear side, albeit at a lower rate and amplitude than on the contralateral side in healthy individuals." The ocular system is unaffected by the saccule. Because of the strong sacculocolic linkages, c–VEMPs are likely to be of saccule origin, while o–VEMPs are thought to be of utricle origin," he concluded.
