Vestibular evoked myogenic potentials (VEMPs) are short-latency bidirectional (p13-n23) electromyograms (EMGs) recorded by strong acoustic stimulation on the surface of the sternocleidomastoid muscle under tension. Currently, some articles translate it as vestibular evoked myogenic potentials, but the authors of this article believe that the translation of vestibular evoked muscle potentials is more in line with the Chinese custom and consistent with the translation of other electroacoustic testing methods.VEMPs can be used to test the responsive vestibular-cervical muscular reflex pathway, and at present, there is a clearer understanding of the VEMPs, and there are more comparisons and studies on the setting of each parameter of the clinical application. VEMPs have been shown to be a trustworthy electroacoustic test for clinical use in the evaluation of vestibular function. Therefore, in this paper, we will briefly introduce the principle of vestibular evoked muscle potentials, especially the characteristics of the current clinical use. I. Origin of VEMPs The hypothesis that VEMPs originate from the vestibular bulbar patch has been continuously confirmed by animal and clinical trials, and the current controversy is whether the cochlear component is involved in the formation of VEMPs.Tsutsumi et al. found that VEMPs could be elicited in some patients with acoustic neuromas originating from the inferior vestibular nerve (about 30%), and that the preservation of the postoperative hearing level was related to the VEMPs. VEMPs, with patients with normal preoperative hearing tending to have no change in their postoperative VEMPs. The prolonged latency of VEMPs in some patients with hearing loss can also be explained by the fact that cochlear nerve fibers are associated with vestibular neurons, making it difficult to determine the origin of VEMP5. Wu, CC et al. found that normal VEMPs could be elicited from the affected side of patients with sudden deafness, suggesting that there is no cochlear component involved in the formation of VEMPs. Takegoshi H et al. found that the effect of white noise on VEMPs in patients with sudden deafness was not significant in their study. The effect of white noise on VEMPs indicated that VEMPs are independent of the cochlear nerve and that the effect of the cochlear component on VEMPs is only present in the stapedius muscle reflex. In this experiment they found that in normal subjects exposed to white noise of 95 dBnHL in the ipsilateral or contralateral ear, the amplitude of VEMPs decreased significantly, whereas in white noise of 75 dBnHL there was a decrease in the amplitude of the V-wave of the ABR although the decrease in the amplitude of the V-wave of the VEMPs was not significant. However, hundred noise at 95dBnHL had no effect on VEMPs on the affected side of patients with unilateral facial paralysis.Ozeki[4] et al. found that patients with severe sensorineural deafness who had atrophy of the cochlear nerve in the VIIIth cranial nerve were also able to elicit VEMPs, suggesting that the VEMP response is not related to the cochlea. Second, the characteristics of VEMPs and collection methods. 1.Characteristics of the conduction pathway of VEMPs. The VEMPs conduction pathway includes the globus pallidus, the inferior vestibular nerve, the lateral vestibular nucleus, the vestibulothalamic tract, and the motor neurons of the ipsilateral sternocleidomastoid muscle.Murofushi T et al. found that most of the subjects recorded VEMPs only in the ipsilateral sternocleidomastoid muscle when the stimulus was given by the Tone Burst and Click monaural stimulus sound and the middle-superior subpotentials of the sternocleidomastoid muscle were recorded at the same time bilaterally,suggesting that Akin FW et al. tilted the subject’s head to one side and gave the sound to this side, and recorded the VEMPs on the surface of the tense and relaxed sternocleidomastoid muscles respectively, and found that the VEMPs were only recorded on the surface of the tense sternocleidomastoid muscle on the same side as the stimulus sound, which supported the unilateral nature of the VEMPs. 2. Characteristics of VEMPs wave amplitude and latency. In observing the effects of stimulus intensity and the wave amplitude and latency of VEMPs, Akin et al. found that the wave amplitude increased with the stimulus intensity, whereas the latency did not change with the stimulus intensity. Moreover, there is an inverse correlation between the frequency and latency of short pure tones. This view is currently agreed by scholars. 3, The mode of acquisition of VEMPs. Al-Abdulhadi K[8] et al. took three conditions of no sternocleidomastoid muscle contraction/no stimulus sound, sternocleidomastoid muscle contraction/no stimulus sound and sternocleidomastoid muscle contraction/stimulus sound in their tests on normal subjects, and the results suggested that satisfactory VEMPs could be obtained only when stimulus sound was given under the condition of sternocleidomastoid muscle contraction. Sheykholeslami K et al. placed the Sheykholeslami K et al. placed the recording electrodes on the upper, middle and lower portions of the sternocleidomastoid muscle, and bi-directional waves (p13-n23) were recorded in the upper and middle portions, respectively. The wave amplitude obtained in the upper portion was the largest, but its latency was unstable, whereas the amplitude of the wave in the middle portion was small, but the latency was constant, so that the middle portion of the sternocleidomastoid muscle should be chosen as the location for placing the electrodes. 4, Unilateral and bilateral recording of VEMPs. Many scholars have adopted the supine decubitus head-up position, with the head tilted to the contralateral side to stimulate the ipsilateral sternocleidomastoid muscle to obtain unilateral recordings of VEMPs, which cannot be tolerated by people with lesions of the vestibular system for a long period of time.Brantberg and Fransson reported that symmetrical VEMPs could be obtained in bilateral sternocleidomastoid muscles when acoustic stimulation was given binaurally at the same time, and that the patient was placed in the supine position with the head upward in the test process. Wang SJ et al. attempted to record VEMPs bilaterally in healthy subjects and in patients with Meniere’s disease and compared them with unilateral recordings, noting that simultaneous recording of VEMPs bilaterally had equal stimulation rates, latencies, and interaural amplitude difference ratios (I AD). difference ratio (I AD), and like unilateral recordings, bilateral recordings are also able to reflect the lesion information of the unilateral conduction pathway of the balloon. Young YH et al. compared the difference between the left and right sides of the VEMPs in bilateral simultaneous testing with short pure tone stimulation of (R-L) 95-95, 85-95, 95-85, and 85-85 dB HL in each ear, and found that the stimulation rate (provocation rate) and p13 were the same as those of unilateral recording. rate and the mean latencies of p13 and n23 were not significantly different between the left and right ears, while the absolute amplitudes of p13-n23 were different between the left and right ears in some subjects, but there was no significant left-right difference in relative amplitudes with respect to the binaural stimulation signals (R-L) 95-95, 85-95, 95-85, and 85-85 dB HL. Moreover, there was no significant difference in their relative wave amplitudes and IAD ratios between subjects with absolute wave amplitude left-right differences and those without differences. Therefore, it is pointed out that the relative wave amplitude and IAD ratio (i.e., the difference between the absolute wave amplitude p13-n23 of the left and right ears divided by the sum of the absolute wave amplitudes of the left and right ears: R-LMR+L) can be used to adjust for the difference between the absolute wave amplitudes of the left and right ears p13-n23, which can be better used for obtaining bilateral VEMPs by giving the sound binaurally under the condition of simultaneous contraction of bilateral sternocleidomastoid muscles in clinical applications. 5. Stimulation Signal selection and parameter settings. The commonly used stimulation signals are short tones and short pure tones. Akin [6] et al. concluded that the stimulus intensity should be 95-100 dB nHL, and the waveform of VEMPs obtained from short pure tones at 500-750 Hz was the largest, and the latency was the most constant. Cheng et al. found that the plateau period, the rise and fall time, and the stimulus frequency of short pure tone stimulation was 1 ms, the rise and fall time was 2 ms, and the VEMPs obtained at a stimulus frequency of 5 Hz was 2 ms, and the VEMPs obtained at a stimulus frequency of 5 Hz was 1 ms. When the stimulation frequency was 5 Hz, the VEMPs had the smallest interaural differences, the lowest variability of waveforms, shorter examination time and satisfactory signal-to-noise ratios. It was suggested that the parameters of the short pure tone stimulation signal should be set as follows: frequency of 500 Hz, stimulation frequency of 5 Hz, rise and fall time of 1 ms, plateau time of 2 ms. The morphology of the waveforms was the most stable and obvious with such parameters. heykholeslami K et al. suggested that the stimulation signal of bone conduction should be set at a frequency of 200-400 Hz, an intensity of 70 dB nHL, a rise and fall time of 1 ms, a plateau period of 8 ms, and an increase in the frequency of the bone conduction signal to a frequency of 1.5 dB nHL. 1 ms, plateau period of 8 ms, and stimulation frequency of 10 Hz. iii. advances in clinical applications. At present, VEMPs have begun to be widely used in the clinic for the diagnosis and study of various vestibular and auditory nerve diseases, such as Meniere’s disease, acoustic neuroma, multiple sclerosis, vestibular neuritis, delayed membranous labyrinthine effusion, and superior hemicircular canal dehiscence syndrome. Recent research updates include: 1. Meniere’s disease. 1995 American Academy of Otolaryngology-Head and Neck Surgery proposed to categorize Meniere’s disease into four degrees based on the arithmetic mean of the patient’s worst pure tone audiometry of 0.5, 1.0, 2.0, and 3.0 kHz in the six months prior to treatment Degree I, <26 dB; Degree II, 26-40 dB; Degree III, 41-70 dB; and Degree IV, >70 dB. Young YH et al. found a significant difference in absolute amplitude between the left and right ears (p13-n23) when testing the VEMPs of patients diagnosed with unilateral Meniere’s disease and calculating the IAD ratio. A significant correlation was found between the IAD ratio and the degree of hearing loss, suggesting that the IAD ratio can be used as an alternative method of determining the degree of Meniere’s disease.Magliulo G et al. used a combination of glycerol, DPOAE and VEMPs tests for the diagnosis of early endolymphatic hydrops, which is recommended to be a diagnostic protocol for vestibular and auditory nerve disorders. It is also recommended as a diagnostic program for vestibular and auditory nerve diseases. Yang TL et al. used bone conduction stimulation to test VEMPs to differentiate radiologic otitis media from chronic otitis media, and found that most of the chronic otitis media showed normal VEMPs, while most of the radiologic otitis media had prolonged latency, suggesting that radiologic otitis media has a wider range of lesions, such as the posterior portion of the osseous labyrinth and the brainstem, and also explaining the ineffectiveness of periosteal placement or tympanoplasty for radiologic otitis media. It also explains why ossicular tube placement or tympanoplasty is ineffective for radiologic otitis media. 3, vestibular evoked muscle potential air-bone conduction test. Akin et al. in their latest study, discussed the different acoustic characteristics of air and bone conduction headphones when testing VEMP, and attempted to utilize these acoustic characteristics to identify different types of hearing impairment, and their test showed that the bone conduction VEMP can be used to identify conductive hearing loss. 4. Tamaki et al., in their study of the clinical use of VEMP technology to test the hearing of deaf people, attempted to utilize the technology to identify deafness caused by different etiologies and to determine the diagnostic criteria for clinical use. The trial is still in its early stages, and the study has not yet identified any regular VEMP parameters associated with these deafnesses, other than lower than normal VEMP values in the test group. However, the VEMP technique will soon be widely used in the next year or two. IV.PROSPECTS AND OUTLOOK The VEMP technique has been widely accepted as a means of evaluating the integrity of the vestibular nerve pathway, and the diagnostic criteria for vestibular disorders and hearing loss and the criteria for setting each parameter by VEMPs are currently under development. As the research on the origin, characteristics, and various clinical applications of VEMPs continues, VEMP technology will have a broader future.