Parameters of Off-Vertical Axis Rotation in Unilateral and Bilateral Vestibulopathy and Their Correlation with Vestibular Evoked Myogenic Potentials

Off-vertical axis rotation (OVAR) is a laboratory test to assess the otolith function. This study aimed to analyze the parameters of OVAR in patients with unilateral vestibular hypofunction (UVH) and bilateral vestibulopathy (BVP), and to correlate the parameters of OVAR with those of VEMPs. Ten healthy volunteers, 41 UVH, and 13 BVP patients performed OVAR. Bias component (BIC) and modulation component (MOC) of UVH and BVP patients were compared with those of healthy controls. BIC and MOC were correlated with amplitude and interaural difference (IAD) of cervical VEMP (cVEMP) and ocular VEMP (oVEMP). In UVH patients, the direction of BICs to affected side rotation were reversed and the absolute value of BICs were decreased when they were compared to healthy controls. In BVP patients, BICs were markedly attenuated. MOCs were not changed in UVH and BVP patients. There was no statistically significant correlation between VEMPs and OVAR.

Association between vestibular dysfunction and findings of horizontal head-shaking and vibration-induced nystagmus

BACKGROUND: The association between vestibular function and findings of horizontal head-shaking nystagmus (HHSN) and vibration-induced nystagmus (VIN) tests is not well understood. OBJECTIVE: To investigate the association between function in the five distinct vestibular end organs and findings of these nystagmus tests. METHODS: We retrospectively reviewed the medical records of 50 patients with vestibular diseases who underwent HHSN testing, VIN testing, video head impulse testing (vHIT), cervical vestibular evoked myogenic potential testing to air-conducted sound (ACS cVEMP) and ocular VEMP testing to ACS (ACS oVEMP). We performed mixed-effects logistic regression analyses to see whether age, sex or the presence of nystagmus in HHSN or VIN have an association with the presence of peripheral vestibular dysfunction on the opposite side to the direction of nystagmus. RESULTS: The presence of HHSN had a significant association with abnormal vHIT in the lateral semicircular canal (LSCC) on the opposite side to the direction of nystagmus. The presence of VIN had a significant association with abnormal vHIT in all the SCCs and abnormal ACS oVEMP on the opposite side to the direction of nystagmus. CONCLUSIONS: HHSN had an association with LSCC dysfunction alone. VIN had an association with dysfunction in all the SCCs and the utricle.

Diagnostic capabilities of the vestibular evoked myogenic potential test in children with vestibular dysfunction

<p class="abstract"><strong>Background:</strong> Vestibular evoked myogenic potential (VEMP) testing is used in the diagnosis of vestibular disorders. It is an objective method for testing the the otolith organs of the vestibular system. VEMP test is an additional method for diagnosing vestibular neuritis (VN). The combination of cervical VEMP (cVEMP) and ocular VEMP (oVEMP) testing has an advantage in long-term monitoring of patients with VN. The VEMP test is well-studied for adults but studies involving children are insufficient. The aim of this study was to analysis and evaluation of the results from VEMP testing of children diagnosed with vestibular dysfunction. Analysis and evaluation of the results from VEMP testing of children diagnosed with vestibular dysfunction.</p><p class="abstract"><strong>Methods:</strong> History, examination of ENT organs, tone threshold audiometry, tympanometry, otoneurological examination, VEMP test. </p><p class="abstract"><strong>Results:</strong> Children with vestibular dysfunction who were examined showed changes predominantly in the oVEMP test. The upper branch of the vestibular nerve is affected. </p><p class="abstract"><strong>Conclusions:</strong> The VEMP test is an additional method for diagnosing patients with vestibular dysfunction. It is safe when used for children.</p>

Investigating short latency subcortical vestibular projections in humans: what have we learned?

Vestibular evoked myogenic potentials (VEMPs) are now widely used for the noninvasive assessment of vestibular function and diagnosis in humans. This review focuses on the origin, properties, and mechanisms of cervical VEMPs and ocular VEMPs; how these reflexes relate to reports of vestibular projections to brain stem and cervical targets; and the physiological role of (otolithic) cervical and ocular reflexes. The evidence suggests that both VEMPs are likely to represent the effects of excitation of irregularly firing otolith afferents. While the air-conducted cervical VEMP appears to mainly arise from excitation of saccular receptors, the ocular VEMP evoked by bone-conducted stimulation, including impulsive bone-conducted stimuli, mainly arises from utricular afferents. The surface responses are generated by brief changes in motor unit firing. The effects that have been demonstrated are likely to represent otolith-dependent vestibulocollic and vestibulo-ocular reflexes, both linear and torsional. These observations add to previous reports of short latency otolith projections to the target muscles in the neck (sternocleidomastoid and splenius) and extraocular muscles (the inferior oblique). New insights have been provided by the investigation and application of these techniques.

Ocular vestibular evoked myogenic potential (VEMP) reveals subcortical HTLV-1-associated neurological disease

IntroductionVestibular Myogenic Evoked Potential (VEMP) evaluates vestibulo-ocular and vestibulospinal reflexes associated with posture.PurposeTo compare cervical and ocular VEMP in individuals with HTLV-1 associated myelopathy (HAM) and with HTLV-1-asymptomatic infection.Materials and MethodsThis cross-sectional study included 52 HTLV-1-infected individuals (26 HAM and 26 asymptomatic carriers) and 26 negative controls. The groups were similar regarding age and gender. Participants underwent ocular and cervical VEMP that were performed simultaneously. The stimulus used to generate VEMP was a sound, low-frequency toneburst, intensity of 120 decibels normalized hearing level (dB nHL), bandpass filter from 10 to 1,500 Hz, with 100 stimuli at 500 Hertz (Hz) and 50 milliseconds (ms) recording time. An alteration in the electrophysiological waves P13 and N23 for cervical VEMP and N10 and P15 waves for ocular VEMP was compared between groups.ResultsCervical VEMP was different among the groups for P13 (p=0.001) and N23 (p=0.003). Ocular VEMP was similar for N10 (p=0.375) and different for P15 (p=0.000). In the HTLV-1-asymptomatic group, 1(3.8%) individual presented changes in both ocular and cervical VEMP, while in HAM group, 16(61.5%) presented changes in both tests.ConclusionNeurological impairment in HAM was not restricted to the spinal cord. The mesencephalic and thalamic connections, tested by ocular VEMP, were also altered. Damage of the oculomotor system, responsible for eye stabilization during head and body movements, may explain why dizziness is such a frequent complaint in HAM.Authors’ summaryHuman T-cell lymphotropic virus type 1 (HTLV-1) infection is endemic in Brazil and can cause HTLV-1-associated myelopathy (HAM). This neurological disease progresses slowly and, within ten years after its onset, can confine the patient to a wheelchair. Changes in HAM inflammatory characteristics can subsequently occur in the cortex, subcortical white matter, cerebellum, and brainstem. In the present study, we used the electrophysiological test Vestibular Myogenic Evoked Potential (VEMP) to evaluate the thalamic, brainstem, and spinal neural connections. This test evaluates the peripheral and the central vestibular pathway and has been used to test the postural reflexes involved in the control of one’s balance. The VEMP from the oculomotor muscles demonstrated that a subcortical impairment occurs in HAM and can also occur in the asymptomatic phase of HTLV-1 infection.

Quantitative Vestibular Function Testing in the Pediatric Population

Quantitative tests of vestibular function include the caloric test, cervical and ocular vestibular evoked myogenic potential (VEMP), rotary chair, and head impulse test, either at the bedside or utilizing video head impulse test (vHIT). The purpose of this article is to provide an overview of how to perform these tests in children, including which tests are recommended based on the child's age and any modifications or considerations that can be made. A variety of clinical measures have been recommended as screening measures for vestibular loss, which will be reviewed. Symptom questionnaires designed to assess the functional impact of dizziness and vestibular loss in children will also be discussed. If a child complains of dizziness or if vestibular loss is suspected (either by case history or positive screening measure), vestibular function testing is warranted. For vestibular function testing, children aged 0 to 2 years typically receive rotary chair, cervical VEMP, and vHIT if a remote system is available. For children aged 3 to 7 years, vHIT, cervical VEMP, and ocular VEMP are completed, and for children aged 8+ years, vHIT, caloric testing if vHIT is normal, and cervical and ocular VEMP are completed. For all children, modifications to testing can be made, as needed.

Simultaneous recording of cervical and ocular vestibular-evoked myogenic potentials

ObjectiveTo increase clinical application of vestibular-evoked myogenic potentials (VEMPs) by reducing the testing time by evaluating whether a simultaneous recording of ocular and cervical VEMPs can be achieved without a loss in diagnostic sensitivity and specificity.MethodsSimultaneous recording of ocular and cervical VEMPs on each side during monaural stimulation, bilateral simultaneous recording of ocular VEMPs and cervical VEMPs during binaural stimulation, and conventional sequential recording of ocular and cervical VEMPs on each side using air-conducted sound (500 Hz, 5-millisecond tone burst) were compared in 40 healthy participants (HPs) and 20 patients with acute vestibular neuritis.ResultsEither simultaneous recording during monaural and binaural stimulation effectively reduced the recording time by ≈55% of that for conventional sequential recordings in both the HP and patient groups. The simultaneous recording with monaural stimulation resulted in latencies and thresholds of both VEMPs and the amplitude of cervical VEMPs similar to those found during the conventional recordings but larger ocular VEMP amplitudes (156%) in both groups. In contrast, compared to the conventional recording, simultaneous recording of each VEMP during binaural stimulation showed reduced amplitudes (31%) and increased thresholds for cervical VEMPs in both groups.ConclusionsThe results of simultaneous recording of cervical and ocular VEMPs during monaural stimulation were comparable to those obtained from the conventional recording while reducing the time to record both VEMPs on each side.ClinicalTrials.gov identifierNCT03049683.

Cervical and Ocular VEMP Testing in Diagnosing Superior Semicircular Canal Dehiscence

Objective To determine the sensitivity and specificity of ocular and cervical vestibular evoked myogenic potentials (VEMPs) in the diagnosis of superior semicircular canal dehiscence (SCD) and to describe the VEMP response characteristics that are most sensitive to SCD and compare the findings to previous reports. Study Design Case series with chart review. Setting Two tertiary neurotologic referral centers. Subjects and Methods Cervical and ocular VEMP peak-to-peak amplitudes and thresholds from 39 adult patients older than 18 years with surgically confirmed SCD were compared with 84 age-matched controls. Results Using receiver operating characteristic (ROC) curves, cervical VEMP (cVEMP) amplitudes, cVEMP thresholds, and ocular VEMP (oVEMP) amplitudes had areas under the curve of 0.731, 0.912, and 0.856, respectively, all of which were statistically significant ( P < .0001). For cVEMP thresholds, at the clinical equivalent ≤85-dB normalized hearing level (nHL) threshold, the sensitivity and specificity were 97.3% and 31.3%, respectively. At the ≤70-dB nHL threshold, the sensitivity and specificity were 73.0% and 94.0%, respectively. For oVEMP amplitudes >12.0 µV, the sensitivity and specificity were 78.6% and 81.7%, respectively. Conclusion Data from this multicenter study suggest that both cVEMP thresholds and oVEMP amplitudes remain good diagnostic tests for identifying SCD, with each test dependent on a number of factors. The sensitivity and specificity of these individual tests may vary slightly between centers depending on testing parameters used.

Evaluation of Vestibular Functions in Patients with Vogt-Koyanagi-Harada Disease

Vogt-Koyanagi-Harada (VKH) disease is an idiopathic, multisystem autoimmune disorder characterized by bilateral, diffuse granulomatous uveitis associated with neurological, audiovestibular, and dermatological manifestations. The purpose of this study is to investigate vestibular functions in patients with VKH disease. A total of 43 patients with VKH disease in Hokkaido University Hospital were enrolled in this study. Subjective symptoms such as dizziness or vertigo and the results of various vestibular examinations including nystagmus testing, caloric testing, and vestibular-evoked myogenic potential (VEMP) testing were investigated. Eight of 42 patients (19.0%) complained of subjective vestibular symptoms. On the other hand, 12 of 28 patients (42.9%) showed nystagmus, and 7 of 15 patients (46.7%) showed unilateral or bilateral weakness in the caloric test. VEMP testing was performed for 16 patients. Seven (43.8%) and 8 (50.0%) patients were evaluated as abnormal in cervical VEMP and ocular VEMP testing, respectively. The rate of detection of nystagmus was significantly higher than that of subjective symptoms. As vestibular dysfunction in patients with VKH disease cannot be detected through history taking alone, nystagmus testing, caloric testing, and VEMP testing should be performed to evaluate vestibular functions associated with VKH disease. It is considered that abnormal VEMP findings are associated with otolith organ dysfunction.