Diagnostic Significance of Vestibular Evoked Myogenic Potentials for Different Types of Vertigo

Objectives. To study the parameters of vestibular evoked myogenic potentials in patients with various types of vertigo. Materials and methods. A total 77 patients (35 men, 42 women) aged 43.7 ± 12.5 years with vestibular vertigo and postural instability were studied. Surface electrode myography was used to record the activity of the sternocleidomastoid muscle arising in response to sound stimulation of the ipsilateral ear. Results and discussion. As compared with controls, patients with signs of impairment to the central compartment of the vestibular analyzer showed a tendency to an increase in the latent period of the N2 wave and a significant reduction in the amplitude of the P1–N2 complex on both sides ( p < 0.005), without any significant change in the coefficient of asymmetry. Patients with signs of damage to the peripheral compartment of the vestibular analyzer showed signifi cant increases in the latent period of P1 as compared with healthy subjects ( p < 0.005). In addition, there was a statistically signifi cant ( p = 0.0007) increase in the coefficient of asymmetry of latent period P1. Patients with postural instability showed no significant differences in P2 and N2 latencies as compared with controls. Conclusions. The study results showed that patients with vertigo of both peripheral and central genesis have impairments to the formation of the vestibulospinal reflex at different levels of the vestibular analyzer.