Vestibular-Evoked Myogenic Potential Testing in Vestibular Localization and Diagnosis

Abstract

Vestibular-evoked myogenic potentials (VEMPs) are short-latency, otolith-dependent reflexes recorded from the neck and eye muscles. They are widely used in neuro-otology clinics as tests of otolith function. Cervical VEMPs are recorded from the neck muscles and reflect predominantly saccular function, while ocular VEMPs are reflexes of the extraocular muscles and reflect utricular function. They have an important role in the diagnosis of superior canal dehiscence syndrome and provide complementary information about otolith function that is useful in the diagnosis of other vestibular disorders. Like other evoked potentials, they can provide important localizing information about lesions that may occur along the VEMP pathway. This review will describe the VEMP abnormalities seen in common disorders of the vestibular system and its pathways.

Dizziness in Parkinson’s disease patients is associated with vestibular function

“…Other NMSs disorders were also associated with VEMP responses, including sleep, perception, cognition, urinary problems, cardiovascular, and sexual dysfunction, although seemingly unrelated to vestibular function 6 , 9 , 10 . It was explained by the degeneration of several brainstem nuclei responsible for the motor and NMSs 9 , and by the VEMP circuit that spans the midbrain, the pons, and the medulla 14 , 15 . Considering our results that patient dizziness may result from vestibular dysfunction and the fact that VEMPs are useful to evaluate the vestibular system, we think that it may be clinically reasonable that VEMPs reflect dizziness rather than other NMSs in PD patients.…”

“…The reason for the different responses is unclear. VEMPs are short-latency, otolith-dependent reflexes recorded from the eye (oVEMPs) and neck muscles (cVEMPs) 15 . The anatomical pathways of these two VEMPs are thought to be different.…”

“…The oVEMP pathway presumably starts from the vestibular nucleus, crosses the midline, and ascends through the medial longitudinal fasciculus (MLF) at the upper pons and midbrain level, then to the ocular motor nuclei. The cVEMP presumably involves a descending pathway from the vestibular nucleus, ipsilateral medial vestibulospinal tract in the pons and medulla, then to the accessory motor neurons 14 , 15 . It has been suggested that upper brainstem function might be involved and lower brainstem function preserved in early PD patients 8 .…”

Recent advances in the epidemiology and diagnosis of some common vestibular disorders

“…The abnormalities of the cervical and ocular vestibular evoked myogenic potentials in common disorders of the vestibular system and its pathways are reviewed (33). According to M. Strupp et al (31), there are already internationally accepted diagnostic criteria for benign positional paroxysmal vertigo, Menière's disease, bilateral vestibulopathy, vestibular paroxysmia, and functional dizziness.…”

Diagnosing vestibular hypofunction: an update

“…This implies that absent responses also appear in non-symptomatic healthy individuals, especially above the age of 60 years old [ 104 ]. The role of VEMP in clinical practice has been investigated extensively regarding diagnostics, prognosis, and monitoring of vestibular disorders [ 105 , 106 ].…”