Cervical VEMP Research Articles

Ocular Vestibular Evoked Myogenic Potential to Air Conducted Sound Stimulation and Video Head Impulse Test in Acute Vestibular Neuritis

Air-conducted (ACS) cervical VEMP (cVEMP) reflect both saccular and inferior vestibular nerve function. Ocular VEMP (oVEMP) to air and bone-conducted vibration (BCV) are critically discussed, whether they reflect predominantly utricular and superior vestibular nerve function. The video head impulse test (vHIT) accurately detects changes in the high frequency range (5-7 Hz) of the vestibular ocular reflex (VOR) in all 3 planes and can be used to assess semicircular canals (SCC) impairment. To evaluate oVEMP and cVEMP in response to 500 Hz ACS stimulation and to compare these with vHIT results in acute unilateral vestibular neuritis (VN) to classify the probable involvement of SCC and otolith organs. Patients with VN were studied. ACS oVEMP and ACS cVEMP (100 dB nHL 500 Hz tone burst stimulation) were recorded. The vHIT for the 3 SCC were performed simultaneously. ACS oVEMP and ACS cVEMP in combination with vHIT allows the differentiation of 4 types of VN: entire VN (EVN), superior VN (SVN), inferior VN (IVN), and ampullary VN (AVN). Lesions of EVN, SVN, and IVN may be either complete or partial. ACS oVEMP and ACS cVEMP to 500 Hz stimulation together with the vHIT allows a better differentiation of receptor involvement in VN. Results suggest a different origin of AC oVEMP and AC cVEMP to 500 Hz in complete SVN and IVN. Partial SVN and IVN may indicate a role of saccular fibers in oVEMP.

A Proposed Method to Comprehensively Define Outcomes in Acoustic Tumor Patients Undergoing CyberKnife Management

Background: Vestibular assessment in patients with acoustic tumor (so-called vestibular schwannoma, VS) via ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests are not often discussed in the neurosurgical literature. Objectives: This study conducted physiological and morphological assessments for VS patients before and after CyberKnife radiosurgery. Methods: Twenty patients with unilateral VS underwent a battery of tests comprising facial nerve function test, audiometry, and caloric, oVEMP and cVEMP tests before and 2 years after CyberKnife treatment at a mean dosage of 18 Gy in 3 fractions. Results: The abnormal percentages of caloric, oVEMP and cVEMP tests did not significantly differ before and after Cyberknife treatment, indicating that preservation of the superior and inferior vestibular nerves can be achieved after radiosurgery. Median tumor volumes, 1.49 cm³ before treatment versus 0.97 cm³ at 2 years after treatment, differed significantly. Conclusions: The use of oVEMP and cVEMP tests in VS patients before stereotactic radiosurgery may help to evaluate the tumor origin from the superior or inferior vestibular nerve. It takes a short time and costs less, and it would be practical to make this a routine examination in VS patients having stereotactic radiosurgery.

Ocular Versus Cervical VEMPs in the Diagnosis of Superior Semicircular Canal Dehiscence Syndrome

To determine whether cervical vestibular evoked myogenic potential (cVEMP) thresholds or ocular VEMP (oVEMP) amplitudes are more sensitive and specific in the diagnosis of superior semicircular canal dehiscence syndrome (SCDS). Prospective case-control study. Tertiary referral center. Twenty-nine patients with SCDS (mean age 48 yr; range, 31-66 yr) and 25 age-matched controls (mean age 48 yr; range, 30-66 yr). cVEMP and oVEMP in response to air-conducted sound. All patients underwent surgery for repair of SCDS. cVEMP thresholds; oVEMP n10 and peak-to-peak amplitudes. cVEMP threshold results showed sensitivity and specificity ranging from 80% to 100% for the diagnosis of SCDS. In contrast, oVEMP amplitudes demonstrated sensitivity and specificity greater than 90%. oVEMP amplitudes are superior to cVEMP thresholds in the diagnosis of SCDS.

Frequency Tuning of the Cervical Vestibular-Evoked Myogenic Potential (cVEMP) Recorded from Multiple Sites along the Sternocleidomastoid Muscle in Normal Human Subjects

Frequency tuning of tone burst-evoked myogenic potentials recorded from the sternocleidomastoid muscle (cervical VEMP or cVEMP) is used clinically to assess vestibular function. Understanding the characteristics of cVEMP is important for improving the specificity of cVEMP testing in diagnosing vestibular deficits. In the present study, we analyzed the frequency tuning properties of the cVEMPs by constructing detailed tuning curves and examining their morphology and dependence on SCM tonic level, sound intensity, and recording site along the SCM. Here we report two main findings. First, by employing nine tone frequencies between 125 and 4,000 Hz, some tuning curves exhibited two distinct peaks, which cannot be modeled by a single mass spring system as previously suggested. Instead, the observed tuning is better modeled as linear summation of two mass spring systems, with resonance frequencies at ~300 and ~1,000 Hz. Peak frequency of cVEMP tuning curves was not affected by SCM tonic level, sound intensity, and location of recording site on the SCM. However, sharpness of cVEMP tuning was increased at lower sound intensities. Second, polarity of cVEMP responses recorded from the lower quarter of the SCM was reversed as compared to that at the two upper sites. While more studies are needed, these results suggest that cVEMP tuning is mediated through multiple generators with different resonance frequencies. Future studies are needed to explore implications of these results on development of selective VEMP tests and determine the nature of polarity inversion at the lower quarter of SCM.

Augmented Ocular Vestibular Evoked Myogenic Potentials to Air-Conducted Sound in Large Vestibular Aqueduct Syndrome

To demonstrate the value of recording air-conducted ocular Vestibular Evoked Myogenic Potentials (oVEMP) in a patient with bilaterally enlarged vestibular aqueducts. Cervical VEMP and oVEMP were recorded from a patient presenting with bilateral hearing loss and imbalance, attributable to large vestibular aqueduct syndrome. The stimuli were air-conducted tone bursts at octave frequencies from 250 to 2000 Hz. Amplitudes and thresholds were measured and compared with the normal response range of 32 healthy control subjects. oVEMP reflexes demonstrated pathologically increased amplitudes and reduced thresholds for low-frequency tone bursts. Cervical VEMP amplitudes and thresholds were within normal limits for both ears across all frequencies of stimulation. This study is the first to describe the augmentation of AC oVEMPs in an adult with large vestibular aqueduct syndrome.

Ocular vestibular evoked myogenic potentials induced by air-conducted sound in patients with acute brainstem lesions

ObjectiveThe ocular vestibular-evoked myogenic potential (oVEMP), a recently documented otolith-ocular reflex, is considered to reflect the central projections of the primary otolithic afferent fibers to the oculomotor nuclei. The aim of our study is to define air-conducted sound oVEMP abnormality in patients with acute brainstem lesions and to determine the brainstem structures involved in the generation of oVEMPs. MethodsIn response to air-conducted tone burst sounds (ACS), oVEMP was measured in 52 patients with acute brainstem lesions. Individualized brainstem lesions were analyzed by means of MRI-based voxel-wise lesion-behavior mapping, and the probabilistic lesion maps were constructed. ResultsMore than half (n=28, 53.8%) of the patients with acute brainstem lesions showed abnormal oVEMP in response to ACS. The majority of patients with abnormal oVEMPs had lesions in the dorsomedial brainstem that contains the medial longitudinal fasciculus (MLF), the crossed ventral tegmental tract (CVTT), and the oculomotor nuclei and nerves. ConclusionMLF, CVTT, and the oculomotor nuclei and nerves appear to be responsible for otolith-ocular responses in the brainstem. SignificanceComplemented to cervical VEMP for the uncrossed otolith-spinal function, oVEMP to ACS may be applied to evaluate the crossed otolith-ocular function in central vestibulopathies.

Development of ocular vestibular‐evoked myogenic potentials in small children

This study investigated the development of otolithic-ocular reflex in small children (<3 years old) via the ocular vestibular-evoked myogenic potential (oVEMP) test. Prospective study. Twenty full-term newborns (group A), 15 children aged 1 to 3 years (group B), and 15 children aged 4 to 13 years (group C) were enrolled in this study. All children underwent auditory brainstem response testing or audiometry, and the oVEMP test. All subjects had normal hearing. Typical biphasic oVEMP waveforms were not observed in the 20 newborns, but were present in six (40%) of 15 children aged 1 to 3 years and all (100%) children aged 4 to 13 years, exhibiting a significant difference. In group B, except for the nine children aged 12 to 24 months, the remaining six children, aged 25 to 47 months, had clear oVEMPs, with the mean nI latency and nI-pI amplitude resembling those in children aged 4 to 13 years, indicating that the otolithic-ocular reflex is mature in children aged >2 years. Despite the well-developed caloric and cervical VEMP responses in early life, oVEMPs are not present in newborns, but are present in children aged >2 years who can walk with a gait resembling an adult. Maturation of the otolithic-ocular reflex is important to balance control, which is necessary in small children for independent gait.

Abnormality of cervical vestibular-evoked myogenic potentials and ocular vestibular-evoked myogenic potentials in patients with recurrent benign paroxysmal postitional vertigo

Conclusion: Our results show that cervical vestibular-evoked myogenic potential (cVEMP) or ocular VEMP (oVEMP) abnormalities in the recurrent benign paroxysmal positional vertigo (BPPV) group were significantly higher than those in the non-recurrent BPPV group. Therefore, we can infer that VEMP abnormality is one of risk factors for BPPV recurrence. Objective: This prospective study aimed to test the hypothesis that otolith dysfunction using the VEMP test is a cause of recurrence of BPPV. Methods: cVEMP and oVEMP tests using 500 Hz tone-burst stimuli were performed on 16 patients with recurrent BPPV between March 2010 and December 2011. Both VEMP tests were performed in 20 patients with non-recurrent BPPV. Results: The differences in age, sex, and involved canal between the recurrent and non-recurrent BPPV groups were not significant. Abnormal cVEMP responses were detected in 5 of 16 (31.3%) subjects in the recurrent BPPV group and abnormal oVMEP responses were detected in 4 of 16 (25%) subjects in the recurrent BPPV group. When we defined VEMP abnormality as an abnormal cVEMP or abnormal oVEMP, VEMP abnormalities were detected in eight (50%) subjects in the recurrent BPPV group and in three (15%) subjects in the non-recurrent BPPV group; the difference between groups was significant.

Ocular and Cervical Vestibular-Evoked Myogenic Potentials in Tumarkin Falls

This study applied ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests in Ménière's patients with Tumarkin falls to investigate the etiologic role of the saccule/utricle in the event of Tumarkin falls. Retrospective study. University hospital. Twenty unilateral definite Ménière's patients were divided into 2 age- and sex-matched groups. Ten patients had a history of drop attacks, and 10 had no history of drop attacks. All patients underwent audiometry and caloric, oVEMP, and cVEMP tests. No significant differences were observed between the fall and nonfall groups in terms of Ménière staging, and caloric and cVEMP test results. In the fall group, oVEMP test via Fz tapping showed augmented, reduced, and absent responses in 1, 1, and 8 patients, respectively. In 3 of the latter 8 patients, however, oVEMPs could be obtained by lateral mastoid tapping. Thus, 100% of patients in the fall group had abnormal oVEMPs, which significantly differed from 50% oVEMP abnormalities in the nonfall group. Comparison of the abnormal results for the caloric, oVEMP, and cVEMP tests revealed that poorer residual vestibular function in the fall group than the nonfall group. Absence of oVEMP by Fz tapping and presence of oVEMPs via lateral tapping indicates a residual utricular function. With residual canal function (canal paresis) and absent cVEMPs, subsequently residual utricular function may trigger the Tumarkin falls in Ménière's patients.

Does unilateral utricular dysfunction cause horizontal spontaneous nystagmus?

The presence of spontaneous nystagmus in darkness with a strong horizontal component has been taken to indicate that there is asymmetrical function of the horizontal semicircular canals. If this horizontal spontaneous nystagmus can be suppressed by vision, then it is regarded as due to peripheral horizontal canal dysfunction. However, we report evidence from one patient (61-year-old male), who visited the MSA ENT Clinic, Cassino (FR) Italy, reporting acute, severe vertigo, postural unsteadiness, nausea and vomiting associated with right sudden hearing loss. The patient received instrumental audiovestibular testing to obtain objective measurements of his inner-ear receptors. At the time of the attack, the patient showed spontaneous nystagmus, mainly with horizontal and vertical components (3D infrared video-oculography). Video head-impulse tests of dynamic horizontal canal function showed that the functional status of both horizontal canals was within the normal range. Cervical VEMPs to 500 Hz bone-conducted vibration at Fz showed normal results; ocular VEMPs to the same stimulus showed a reduced n10 amplitude beneath the left eye, corresponding to the right ear. For this reason, the patient was diagnosed as having right unilateral selective utricular macula lesion due to labyrinthitis. There is considerable evidence of convergence of neural input from the otoliths onto horizontal canal neurons in the vestibular nuclei. The firing of such neurons could reflect either asymmetrical horizontal canal function or asymmetrical utricular function. The problem with this patient was not due to asymmetrical horizontal canal function, but only to asymmetrical utricular function, demonstrated by the results of the oVEMP test.

The Use of Vestibular Test Battery to Identify the Stages of Delayed Endolymphatic Hydrops

Patients with delayed endolymphatic hydrops (DEH) underwent a vestibular test battery to evaluate the residual function, assess their clinical stage, and predict outcome. Case series with chart review. Setting University hospital. Twenty patients with DEH, 15 with ipsilateral type and 5 with contralateral type, were enrolled. All patients underwent audiometry and caloric, ocular vestibular-evoked myogenic potential (oVEMP), and cervical VEMP (cVEMP) tests. The DEH staging was based on vestibular test results. Stage 0 indicates that all 3 vestibular tests are normal, while stages I through III indicate abnormal results in tests 1 through 3, respectively. Of the 20 DEH patients, 2 patients were stage 0, 12 patients were stage I, 4 patients were stage II, and 2 patients were stage III. The median frequency of vertigo in patients with stages II and III was 4 episodes monthly, significantly less than 15 episodes monthly in those with stages 0 and I. Ipsilateral and contralateral types did not differ significantly in the stage distribution. The percentages of abnormal cVEMP, oVEMP, and caloric test results for patients with ipsilateral type were 80%, 33%, and 13%, not significantly different from those for contralateral type. As a vertiginous attack may subside spontaneously for patients with long-term DEH, one must identify its clinical stage based on cVEMP, oVEMP, and caloric test results. In early stage DEH, most vestibular function remained relatively intact, leading to repeated vertiginous attacks. Conversely, subsidence of vertiginous episode can be anticipated in patients with late stage DEH.

Assessment of the otolith-ocular reflex using ocular vestibular evoked myogenic potentials in patients with episodic lateral tilt sensation

The otolith-ocular reflex in patients with episodic lateral tilt sensation without any other vestibular symptoms was assessed using ocular vestibular evoked myogenic potentials (oVEMP). Ten patients (6 men and 4 women, mean age=53.5) were enrolled. All patients had episodic lateral tilt sensation. Patients with a medical history of rotatory vertigo, loss of consciousness, head trauma, or symptoms or signs of central nervous dysfunction or proprioceptive dysfunction and those who had been definitely diagnosed with a disease that causes disequilibrium were excluded. All of the 10 patients had oVEMP tests and cervical VEMP (cVEMP) tests and underwent caloric tests. Eight of the 10 patients showed unilateral absence of oVEMP, one displayed a bilateral absence, and one displayed normal oVEMP. Concerning cVEMP, 4 patients showed a unilateral absence of cVEMP, one displayed unilaterally decreased responses and 5 displayed normal cVEMP. All patients showed normal bilateral caloric responses. The present study showed that patients with episodic lateral tilt sensation displayed abnormal otolith-ocular reflexes, as shown by their oVEMP, suggesting that these patients were suffering from utricular dysfunction.

Ocular and cervical vestibular evoked myogenic potentials in multiple sclerosis patients

ObjectiveVestibular evoked myogenic potentials (VEMPs) are thought to provide useful information about brainstem functions, as the neural pathways of both ocular and cervical VEMPs pass through the brainstem. The aim of this study was to investigate the clinical value of ocular and cervical VEMP tests in the evaluation of brainstem involvement in multiple sclerosis (MS) patients and to assess their relation with clinical and cranial MRI findings. MethodsOcular and cervical VEMPs were recorded in 62 MS patients and 35 age and sex matched healthy volunteers. The latencies, amplitude asymmetry ratios of both VEMP responses and abnormality ratios (prolonged latencies and absent responses) were compared between the MS patients and the control group and among the groups of MS patients. ResultsoVEMP mean n1 and p1 latencies and cVEMP mean p13 latency were significantly prolonged in MS patients. Although the abnormality ratios of both VEMPs were higher in patients with brainstem clinical or MRI lesions, the correlation was not statistically significant. Both ocular and cervical VEMP latencies were significantly correlated with expanded disability status scale. ConclusionsAlthough there is no significant correlation with clinical or MRI findings, MS patients show high frequency of abnormality in VEMP tests, especially in oVEMP tests. SignificanceVEMP tests may be useful as an adjunct test in the evaluation of brainstem dysfunction in MS patients.

Augmentation of Ocular Vestibular‐Evoked Myogenic Potentials via Bone‐Conducted Vibration Stimuli in Ménière Disease

The asymmetry ratio of ocular vestibular-evoked myogenic potential (oVEMP) >40% is interpreted as augmented or reduced response depending on whether the nI-pI amplitude of the lesion ear is larger or smaller than that of the opposite ear, respectively. This study compared unilateral Ménière disease patients with augmented oVEMPs vs reduced oVEMPs to elucidate the mechanism of augmented oVEMP. Case series with chart review. University hospital. Forty patients with unilateral definite Ménière disease were enrolled in this study, including 20 patients with augmented oVEMPs and another 20 patients with reduced oVEMPs in the hydropic side. All patients underwent audiometry, caloric test, and oVEMP and cervical VEMP (cVEMP) tests via bone-conducted vibration stimuli. Then, the oVEMP and cVEMP test results were compared with the stage of Ménière disease, respectively. The augmented group had earlier nI and pI latencies and larger nI-pI amplitude of oVEMPs compared with the reduced group. Caloric test also revealed a significant difference in abnormal responses between the augmented and reduced groups. However, both groups did not differ significantly in the abnormal percentage of cVEMP test results. A significant trend to decline in the prevalence of augmented oVEMPs was noted from stages I to III-IV but not in that of abnormal cVEMPs. The augmented oVEMPs have earlier latencies and larger amplitudes compared with the reduced oVEMPs, indicating that a relatively larger population of intact utricular afferents is activated during the early stage of Ménière disease.

Correlation between caloric and ocular vestibular evoked myogenic potential test results

Conclusion: The ocular vestibular evoked myogenic potential (o-VEMP) test results correlate significantly with caloric test results for patients with acoustic neuroma (AN), but not for patients with Meniere's disease (MD), indicating that the o-VEMP test may replace the caloric test for evaluating the vestibular nerve from which the AN arises. Conversely, the caloric, o-VEMP, and cervical VEMP (c-VEMP) tests should be performed to map lesion sites in the vestibular labyrinth. Objective: This study performed caloric, o-VEMP, and c-VEMP tests on patients with central and peripheral vestibular disorders to investigate their relationships. Methods: In all, 66 patients comprising 16 with unilateral AN and 50 with unilateral definite MD were enrolled. All patients underwent caloric, o-VEMP, and c-VEMP tests. Results: In the AN group, the caloric test identified canal paresis and caloric areflexia in 10 ears, while the o-VEMP and c-VEMP tests identified abnormal (absent or delayed) responses in 12 and 11 ears, respectively. A significant correlation existed between caloric and o-VEMP test results, but not between caloric and c-VEMP test results, or between o-VEMP and c-VEMP test results. For the MD group, abnormal caloric, o-VEMP, and c-VEMP test results were obtained for 24%, 44%, and 38% of hydropic ears, respectively. No correlation existed between any two test results.

Ocular vestibular evoked myogenic potentials to air conduction (AC oVEMP): Useful in clinical practice?

Cervical vestibular-evoked myogenic potential (cVEMP) and ocular VEMP (oVEMP) stimuli can be used to measure otolith function using air (AC) and bone conducted (BC) stimuli. Cervical VEMPs reflect saccular function and can be recorded using air conduction (AC), whereas oVEMPs reflect probably predominantly utricular function. Air- and bone-conducted vibration can be used, because AC oVEMP methodology seems to be fast and simple in clinical practice to measure otolith function. In this study we discuss the advantages and problems of AC oVEMP stimulation. AC oVEMP can be easily and quickly obtained within a few seconds. N10 (first negative peak) and p15 (first positive peak) latencies may be used as parameters for clinical interpretation but amplitude fluctuations are relatively large. For daily clinical use of VEMP visualization in a normogram seems feasible. Especially the AC oVEMP methodology (100 dB nHL, tone burst 500 Hz) is fast and efficient in clinical practice to measure otolith function, predominantly utricular function.

Cervical and ocular vestibular-evoked myogenic potentials in acute vestibular neuritis

Objectives To clarify the origin and afferent pathways of short-latency ocular vestibular-evoked myogenic potential (oVEMP) in response to air-conducted sound (ACS), we evaluated cervical (cVEMP) and ocular VEMPs in patients with vestibular neuritis (VN). Methods In response to air-conducted tone burst, the oVEMP and cVEMP were measured in 60 healthy controls and in 41 patients with acute VN. The VN selectively involved the superior vestibular nerve (superior VN) in 30 patients, affected the inferior vestibular nerve only (inferior VN) in three and damaged both superior and inferior vestibular nerve branches in eight. Results All 30 patients with superior VN presented normal cVEMPs, indicating preservation of the saccular receptors and their afferents in the inferior vestibular nerve. However, the oVEMP was abnormal in all patients with superior VN. By contrast, the patients with inferior VN showed normal oVEMP and abnormal cVEMP. Conclusion These dissociations in the abnormalities of cVEMP and oVEMP in patients with VN selectively involving the superior or inferior vestibular nerve suggest that the origin of the vestibular nerve afferents of oVEMP differ from those of cVEMP. Significance The oVEMP in response to ACS may be mediated by the superior vestibular nerve, probably due to an activation of the utricular receptors.

Click-evoked responses in vestibular afferents in rats

Sound activates not only the cochlea but also the vestibular end organs. Research on this phenomenon led to the discovery of the sound-evoked vestibular myogenic potentials recorded from the sternocleidomastoid muscles (cervical VEMP, or cVEMP). Since the cVEMP offers simplicity and the ability to stimulate each labyrinth separately, its values as a test of human vestibular function are widely recognized. Currently, the cVEMP is interpreted as a test of saccule function based on the assumption that clicks primarily activate the saccule. However, sound activation of vestibular end organs other than the saccule has been reported. To provide the neural basis for interpreting clinical VEMP testing, we employed the broadband clicks used in clinical VEMP testing to examine the sound-evoked responses in a large sample of vestibular afferents in Sprague-Dawley rats. Recordings were made from 924 vestibular afferents from 106 rats: 255 from the anterior canal (AC), 202 from the horizontal canal (HC), 177 from the posterior canal (PC), 207 from the superior vestibular nerve otolith (SO), and 83 from the inferior nerve otolith (IO). Sound sensitivity of each afferent was quantified by computing the cumulative probability of evoking a spike (CPE). We found that clicks activated irregular afferents (normalized coefficient of variation of interspike intervals >0.2) from both the otoliths (81%) and the canals (43%). The order of end organ sound sensitivity was SO = IO > AC > HC > PC. Since the sternocleidomastoid motoneurons receive inputs from both the otoliths and the canals, these results provide evidence of a possible contribution from both of them to the click-evoked cVEMP.

Association of air-conducted sound oVEMP findings with cVEMP and caloric test findings in patients with unilateral peripheral vestibular disorders

Conclusion: This study showed that the ocular vestibular evoked myogenic potential (oVEMP) in response to air-conducted sound (ACS) reflects functions of different parts of the vestibular labyrinth from cervical VEMP (cVEMP). Objective: To determine whether the origin of the vestibular end organs of the oVEMP in response to ACS (500 Hz tone bursts) is the same as that of cVEMP. Methods: Twenty patients definitively diagnosed with unilateral Meniere's disease (MD), 6 patients with unilateral vestibular neuritis (VN), and 7 healthy subjects were enrolled. In these subjects, the oVEMP and cVEMP to air-conducted 500 Hz tone bursts (125 dBSPL) were measured. The patients also underwent caloric tests. Results: The MD patients did not show a significant association between their ACS oVEMP findings and ACS cVEMP findings but there was an association of ACS oVEMP findings with caloric test findings. When the MD patients were classified into four stages based on their hearing levels, the patients showed abnormal findings at earlier stages on ACS cVEMP than on other tests. While all six VN patients showed abnormal findings on ACS oVEMP and caloric tests, only two patients showed abnormal ACS cVEMPs. These findings support the hypothesis that the oVEMP in response to ACS predominantly reflects utricular functions while ACS cVEMP reflects saccular functions.

Identifying the affected branches of vestibular nerve in vestibular neuritis

Conclusion. The inner ear monitoring system is useful for identifying the affected branches of the vestibular nerve in cases of vestibular neuritis, providing insight about the interval for the relief of vertigo. Objective: This study conducted an inner ear monitoring system including audiometry, and caloric, ocular vestibular evoked myogenic potential (oVEMP), and cervical VEMP (cVEMP) tests in cases of vestibular neuritis for assessing the affected branches of the vestibular nerve. Methods: Twenty patients with vestibular neuritis underwent caloric, oVEMP, and cVEMP tests. Type I indicates that one of the three tests is abnormal; type II indicates that two test results are abnormal; and type III indicates that no test result is normal. Results: All patients had normal hearing, bilaterally. Nineteen (95%) of 20 patients had abnormal caloric responses, 11 patients (55%) had abnormal oVEMPs, and 5 patients (25%) had abnormal cVEMPs. Restated, of all 20 patients, 8 patients were classified as type I, 9 were type II, and 3 were type III. The mean intervals between presentation and relief of vertigo were significantly different among the three types. One year after treatment, caloric, oVEMP, and cVEMP tests returned to normal responses in three (60%) of five patients.