Vestibular Evoked Myogenic Potentials In Patients Research Articles

Clinical characteristics and analysis of vestibular-evoked myogenic potentials in patients with sudden sensorineural hearing loss in different ages.

Numerous studies have found that patients experiencing sudden sensorineural hearing loss (SSHL), with or without accompanying vertigo, often show impaired vestibular function. However, there is a dearth of studies analyzing vestibular-evoked myogenic potentials (VEMPs) in SSHL patients across various age groups. To investigate vestibular condition in SSHL patients across various age demographics. Clinical data of 84 SSHL patients were investigated retrospectively. Audiometry, cervical vestibular evoked myogenic potentials (c-VEMPs), and ocular vestibular evoked myogenic potentials (o-VEMPs) were conducted on these patients. Parameters assessed included the latencies of P1 and N1 waves, as well as the amplitudes of P1-N1 waves. Moreover, the study evaluated the influence of factors such as sex, affected side, configuration of hearing loss, and presence of accompanying vertigo. Among the 84 SSHL patients, no significant differences were observed among the three groups in terms of gender, affected side, and the presence or absence of vertigo. Group II (aged 41-60 years) had the highest number of SSHL cases. The rates of absent o-VEMPs in the affected ears were 20.83%, 31.58%, and 22.72% for the three age groups, respectively, with no statistically significant difference among them. The rates of absent c-VEMPs in the affected ears were 8.3%, 34.21%, and 18.18% for the three age groups, respectively, with significant differences. In the unaffected ears, there were differences observed in the extraction rates of o-VEMPs in the unaffected ears among the age groups. In the three age groups, no significant differences were noted in the three age groups in the latencies of P1 and N1 waves or in the amplitude of N1-P1 waves for c-VEMPs and o-VEMPs, either on the affected side or on the unaffected side, across the three age groups. The extraction rate of VEMPs is more valuable than parameters. Regardless of the presence of vertigo, vestibular organs are involved in SSHL. Notably, SSHL patients aged 41-60 appear more susceptible to damage to the inferior vestibular nerve and saccule.

Assessment of Vestibular-Evoked Myogenic Potentials in Parkinson's Disease: A Systematic Review and Meta-Analysis.

(1) Background: The brainstem plays an essential role in the early stage of Parkinson’s disease (PD), but it is not widely tested in clinical examinations of PD. Vestibular-evoked myogenic potentials (VEMPs) are recognized as fundamental tools in the assessment of brainstem function. The aim of our meta-analysis was to assess the abnormal findings of VEMPs in patients with PD. (2) Methods: Up to 14 February 2022, PubMed, Embase, and Web of Science were searched to evaluate VEMPs in patients with PD in comparison with respective controls. The study protocol was registered at PROSPERO (CRD42022311103). (3) Results: A total of 15 studies were finally included in our meta-analysis. The absence rates of VEMPs in patients with PD were significantly higher than those of control groups (cVEMP: OR = 6.77; oVEMP: OR = 13.9; mVEMP: OR = 7.52). A delayed P13 latency, a decreased peak-to-peak amplitude, and an increased AAR of cVEMP, and a delayed oVEMP P15 latency were also found in patients with PD. (4) Conclusions: Our meta-analysis indicates abnormal VEMP findings in patients with PD, revealing the dysfunction of the brainstem in PD. VEMP tests, especially cVEMP tests, could be a helpful method for the early detection of PD.

REM sleep without atonia and vestibular-evoked myogenic potentials: clinical brainstem dysfunction in early-stage Parkinson's disease and isolated REM sleep behavior disorder

ObjectiveTo determine whether the onset of rapid eye movement (REM) sleep behavior disorder (RBD) is associated with changes in brainstem neuronal pathway dysfunction as reflected by vestibular-evoked myogenic potentials (VEMPs) and to evaluate associations between VEMPs and REM sleep without atonia (RSWA) in patients with early-stage Parkinson's disease (PD) and isolated RBD (iRBD). MethodsEighty-two early-stage PD patients, 40 iRBD patients, and 41 healthy control individuals underwent one-night video-polysomnography (vPSG) and VEMPs examination. We compared cervical (cVEMP), ocular (oVEMP), and masseter (mVEMP) VEMP parameters among PD with RBD (PD + RBD), PD without RBD (PD-RBD), iRBD, and control groups and analyzed correlations between VEMPs and RSWA in PD and iRBD groups. ResultsThe PD + RBD group showed delays in bilateral cVEMP (Lp13, Ln23, Rn23: all p < 0.05) and oVEMP (Ln10, Rn10, Rp15: all p < 0.05) peak latencies compared with the PD-RBD group. Total cVEMP scores were higher in the PD + RBD group than in the iRBD group (p = 0.033). In PD patients, phasic RSWA was correlated with total cVEMP scores (p = 0.003), and tonic RSWA was correlated with left oVEMP scores (p = 0.013). ConclusionsBrainstem neurophysiology as evidenced by altered VEMPs in patients with PD and iRBD could reflect disease evolvement. Moreover, VEMPs alterations may vary depending on the presence of RBD in PD patients. The associations between altered RSWA and VEMP parameters highlight the meaningfulness of detecting brainstem dysfunction in early-stage PD.

Retro-labyrinthine Lesion Site Detected by Galvanic Vestibular Stimulation Elicited Vestibular-evoked Myogenic Potentials in Patients with Auditory Neuropathy.

Auditory neuropathy (AN) is a unique pattern of hearing loss with preservation of hair cell function. The condition is characterized by the presence of otoacoustic emissions (OAE) or cochlear microphonic (CM) responses with severe abnormalities of the auditory brainstem response (ABR). The vestibular branches of the VIII cranial nerve and the structures innervated by it can also be affected. However, the precise lesion sites in the vestibular system are not well characterized in patients with AN. The air-conducted sound (ACS) vestibular-evoked myogenic potentials (VEMPs) and galvanic vestibular stimuli (GVS)-VEMPs were examined in 14 patients with AN. On examination of VEMPs (n=14, 28 ears), the absent rates of ACS-cervical VEMP (cVEMP), ACS-ocular VEMP (oVEMP), GVS-cVEMP, GVS-oVEMP and caloric test were 92.9% (26/28), 85.7% (24/28), 67.9% (19/28), 53.6% (15/28), and 61.5% (8/13), respectively. Impaired functions of the saccule, inferior vestibular nerve, utricle, superior vestibular nerve, and horizontal semicircular canal were found in 25.0% (7/28), 67.9% (19/28), 32.1% (9/28), 53.6% (15/28) and 61.5% (8/13) patients, respectively. On comparing the elicited VEMPs parameters of AN patients with those of normal controls, both ACS-VEMPs and GVS-VEMPs showed abnormal results in AN patients (such as, lower presence rates, elevated thresholds, prolonged latencies, and decreased amplitudes). The study suggested that patients with AN often have concomitant vestibular disorders. Retro-labyrinthine lesions were more frequently observed in this study. GVS-VEMPs combined with ACS-VEMPs may help identify the lesion sites and facilitate detection of areas of vestibular dysfunction in these patients.

Cervical vestibular-evoked myogenic potentials in patients with essential tremor

Although different neuroanatomical structures and pathways are emphasized as possible explanations for essential tremor (ET), there is still an ongoing debate. This study aimed to assess the role of brainstem and reflex pathways with cervical vestibular-evoked myogenic potentials (VEMP) in patients with ET. This prospective study included 34 patients with ET and 25 healthy controls. Cervical VEMP was performed in both groups and latencies, inter-peak latency intervals, peak-to-peak amplitudes and asymmetry ratios were recorded. There was statistically no significant difference between the groups in terms of age (38.9 ± 14.9 years vs. 38.9 ± 14.9 years, p = 0.673) and gender (female to male ratio: 14/11 vs. 20/14, p = 0.828). Right N1 latency and right N1–P1 interval were significantly longer in the patient group (p < 0.05). There was a significant positive correlation between the duration of disease and the right N1–P1 interval (p < 0.05). There was no significant difference between the patient and control groups in terms of bilateral P1 latency, left N1 latency, left N1–P1 interval, and bilateral N1 and P1 amplitudes (p˃0.05). Cervical VEMP may reveal the involvement of brainstem and associated reflex pathways in ET.

Selective Asymmetry of Ocular Vestibular-Evoked Myogenic Potential in Patients with Acute Utricular Macula Loss.

We retrospectively evaluated a chart review of 3,525 patients evaluated for any acute disturbance. A total of 1,504 patients with acute vestibular syndrome (AVS) received an instrumental vestibular assessment within 72 h from the onset of the symptoms evaluated using simultaneously a combination of ocular vestibular-evoked myogenic potential (oVEMPs), cervical vestibular-evoked myogenic potential (cVEMPs), video head-impulse test (vHIT), and subjective visual vertical (SVV) were included in this study. A total of 41 patients with AVS that showed a normal horizontal canal function tested with vHIT, a normal cVEMP function, unilaterally reduced or absent oVEMP n10, and an altered SVV were enrolled. We found that although these patients referred acute vertigo and presented spontaneous nystagmus, they showed physiological values of vHIT and a normal saccular function, as shown by symmetrical cVEMPs. Our findings support the hypothesis that a percentage of patients evaluated during an AVS using an instrumental vestibular assessment could present selective utricular macula dysfunction.

Cervical and Ocular Vestibular-Evoked Myogenic Potentials in Patients With Intracochlear Schwannomas.

Objective: To evaluate ocular and cervical vestibular evoked myogenic potentials (oVEMPs and cVEMPs) in patients with solely intracochlear localization of an intralabyrinthine schwannoma (ILS).Study Design: Retrospective analysis of a series of cases.Setting: Monocentric study at a tertiary referral center.Patients: Patients with intracochlear schwannoma (ICS) and VEMP measurements.Outcome Measures: Signed asymmetry ratio (AR) of cVEMPs and oVEMPs to air conducted sound with AR cut-offs considered to be asymmetrical when exceeding ±30% for cVEMPs and ±40% for oVEMPs with respect to the side affected by the tumor (reduced amplitudes on the affected side indicated by negative values, enhanced amplitudes by positive values); VEMP amplitudes and latencies; tumor localization in the cochlear turn and scala.Results: Nineteen patients with a solely intracochlear tumor (ICS patients) [10 males, 9 females, mean age 57.1 (SD: 13.4) years] were included in the study. On the affected side, cVEMPs were absent or reduced in 47% of the patients, normal in 32%, and enhanced in 21%. Ocular VEMPs on the affected side were absent or reduced in 53% of the patients, normal in 32% and enhanced in 15%. Latencies for cVEMPs and oVEMPs were not significantly different between the affected and non-affected side. In all patients with enhanced VEMPs, the tumor was located in the scala tympani and scala vestibuli.Conclusions: As a new and unexpected finding, VEMP amplitudes can be enhanced in patients with intracochlear schwannoma, mimicking the third window syndrome.

Vestibular-evoked myogenic potentials in patients with severe obstructive sleep apnea.

ObjectivePrevious studies have shown that patients with obstructive sleep apnea syndrome (OSAS) may have various vestibular abnormalities, and these mainly present as subclinical lesions. In this study, we attempted to combine ocular vestibular-evoked myogenic potentials (VEMPs) and cervical (VEMPs) to investigate vestibular dysfunction in patients with OSAS.MethodsThirty-eight patients with severe OSAS and 42 healthy controls were enrolled and divided into two groups according to results of polysomnography. All parameters of VEMP graphs were analyzed.ResultsThe response rate of ocular VEMPs was significantly lower in patients with severe OSAS (85.5%) than in controls (96.4%). The mean n1 latency of patients with severe OSAS (10.6 ± 1.0 months) was significantly longer than that of controls (10.2 ± 1.1 months). With regard to cervical VEMP, p1-n1 amplitudes were significantly different between the groups. Other VEMP parameters were not significantly different between the groups.ConclusionsVEMPs can potentially be used to evaluate vestibular system lesions at the early stage of OSAS, including not only the vestibular nerve, but also the otolith organs involved.

Clinical value of vestibular-evoked myogenic potential tests in patients with sudden sensorineural hearing loss

BackgroundThis study aims to investigate the clinical value of two kinds of vestibular-evoked myogenic potentials in patients with sudden sensorineural hearing loss (SSNHL).MethodsA total of 82 patients were divided into two groups: vertigo group and non-vertigo group. All patients underwent examinations for pure tone hearing thresholds, middle ear analysis, the videonystagmography, caloric tests, and vestibular-evoked myogenic potentials elicited from the sternocleidomastoid and extraocular muscle. In addition, 30 healthy subjects were selected as the control group.ResultsFor the 30 healthy subjects, the average latency of p13 and n23 of the cervical vestibular evoked myogenic potentials (cVEMPs) were 13.13 ± 2.89 ms and 23.51 ± 3.25 ms, respectively, and the bilateral amplitude asymmetry rate ranged within 0.05–0.31. The average latency of n10 of the ocular vestibular evoked myogenic potentials (oVEMPs) was 10.13 ± 0.48 ms. The average amplitude of the n10-p15-wave was 5.58 ± 0.65 μV. Among the 35 vertigo patients with SSNHL, 27 patients had normal cVEMP and oVEMP examination results, five patients had abnormal oVEMP examination results, and five patients had abnormal cVEMP examination results. The latency and amplifier of oVEMPs and cVEMPs were within the normal range in 47 SSNHL patients without vertigo. The chi-square value was 5.647, the P-value was equal to 0.017, and the difference was statistically significant at a confidence interval of 95%.ConclusionsOVEMPs and cVEMPs can be used evaluate the vestibular nerve function of SSNHL patients with vertigo.

Vestibular-evoked myogenic potentials in patients with large vestibular aqueduct syndrome

Background: The vestibular function in patients of large vestibular aqueduct syndrome (LVAS) has not been clarified yet.Aims/objectives: To investigate the characteristic of otolithic organ in LVAS patients, we accessed their ocular and cervical vestibular evoked myogenic potentials (oVEMPs and cVEMPs).Material and methods: This study was carried out between 29 bilateral LVAS patients and 35 healthy controls. Parameters of VEMPs were analyzed.Result: In children patients, response rate for oVEMP was 93.47% and 86.95% for cVEMP. No statistical significance was found compared to their controls. In adult patients, response rate for oVEMP was 83.33% and 75% for cVEMP, which were statistically lower than their controls. In comparison to parameters of VEMPs, no statistical significance were found in children group. Amplitude of oVEMP was significantly higher and that of cVEMP was lower in LVAS adults. N1 latencies were significantly longer and P1 latencies were shorter in adult patients than in controls of cVEMP. Thresholds and N1-P1 intervals of VEMP were found no statistical significance in adult group.Conclusions and significance: We discovered a severer otolithic dysfunction in adults than in children patients. We recommend cVEMP a more effective and sensitive method than oVEMP in assessment of LAVS adult patients.

Assessment of cervical and ocular vestibular evoked myogenic potentials in multiple sclerosis(MS) patients

Multiple sclerosis (MS) is one of the most important chronic neurological disease affecting the central nervous system and is the leading cause of disability due to brainstem affiction. Vestibular evoked myogenic potentials (VEMPs) are short-latency muscle responses. Cervical VEMP (Cvemp) is a demonstration of vestibule-collic reflex, while ocular VEMP (oVEMP) which is a manifestation of vestibulo–ocular reflexes. The aim of this study was to assess cVEMP and oVEMP in MS patients with and without brainstem lesion(s) and comparing the findings with normal controls. Both latency and amplitude of cVEMP (p13-n23) and oVEMP (n10-p15) were recorded in10 healthy matched controls, 10 MS patients with BS lesion(s)and 10 MS patients without BS lesion(s). All patients underwent a complete audiological examination, clinical neurological evaluation and brain MRI scanning. The latency of P13-N23 and N10-P15 in MS participants with and without BS lesions were significantly prolonged compared to normal controls (p ≤ 0/05). Additionally latency of P13-N23 and N10-P15 in patients of MS with BS lesion(s) were significantly prolonged compared to patients without BS lesion(s) (p ≤ 0.05). No relationship was found between the clinical state and VEMP responses. No relationship was found between the radiological findings of the patient and VEMP responses except for the group of MS with BS affection. A good correlation was found between VEMP latencies and EDSS. Abnormality of cervical VEMP and ocular VEMP in patients of Multiple Sclerosis with brainstem lesion(s) are more frequent than in patients of Multiple Sclerosis without brainstem lesion(s) .

Otolithic Damage Study in Patients With Benign Paroxysmal Positional Vertigo With Vestibular Evoked Myogenic Potentials

IntroductionBenign paroxysmal positional vertigo (BPPV) pathophysiology is based on otoconia migration from the utricle and saccule to the semicircular canals, however, the role of the saccule is still under study. Our aim is to study the otolith damage in these patients with vestibular evoked myogenic potentials (VEMPS) and correlate the results with those of computerised dynamic posturography (CDP). Material and MethodsWe present 79 patients diagnosed with BPPV between March and June 2017. VEMPS and CDP studies were performed. We selected 67 patients with posterior semi-circular canal BPPV and we compared them with 60 healthy subjects. ResultsBPPV group had abnormal cervical VEMPS in 49.25% of patients compared to 16.67% in the control group. Ocular VEMPS were altered in 61.19% of the patients and 6.67% of the healthy subjects. Abnormal ocular VEMPS in patients with recurrent BPPV was statistically significant. There was no significant correlation with CDP results. ConclusionsUtricular and saccular dysfunction in BPPV patients proved by VEMPS is higher than in healthy individuals. This result may be related to symptoms of instability experienced by these patients occasionally.

The role of vestibular evoked myogenic potentials in multiple sclerosis-related vertigo. A systematic review of the literature

BackgroundVertigo is a common symptom of multiple sclerosis (MS) that can be caused by a central or peripheral involvement of the vestibular pathways. Magnetic Resonance Imaging (MRI) is commonly used to evaluate progression of MS but is not sensitive enough to detect small lesions. Vestibular evoked myogenic potentials (VEMPs) are commonly used to evaluate function of vestibular-cochlear pathways. The aim of this literature review is to evaluate the role of VEMPs in patients with MS-related vertigo as a tool to detect demyelinating lesions in the vestibular pathways of MS patients and to monitor MS progression. MethodsFollowing the PRISMA guidelines, we performed a literature search with the following keywords: multiple sclerosis, vertigo, dizziness, equilibrium disorders, vestibular disorders, and VEMPs. Three different databases (PubMed, Scopus, and Google Scholar) were independently screened by two researchers. Publications in English, Italian, French, and Spanish were considered and reviewed by a native speaker. Details on patients’ gender, age, and stage of MS, as well as VEMPs, MRI, and vertigo features (including their onset as a function of MS stage) were collected. Percentage and odds ratio were calculated. Spearman test was used to correlate vertigo, VEMPs, and MRI features. ResultsThirty-five articles and 819 patients were included in the study. Nearly 37% of MS patients suffered from vertigo and 71% showed altered VEMPs. Central vestibular pathways were involved in the MS demyelination mostly in the early stage of the disease, while the peripheral vestibular system was mainly affected in late stage MS. A significant percentage (35.4%) of the patients with altered VEMPs showed normal MRI. ConclusionsOur results suggest that VEMPs may detect very small lesions in the vestibular pathways of MS patients; thus, they could have a role in the diagnosis of MS-related vertigo and in the monitoring of vertigo in MS patients as a tool additional to traditional MRI.

Evaluation of curative effect of VNG and VEMP in patients with severe sudden hearing loss

Objective:To evaluate the relationship between vestibular function and curative effect in patients with severe sudden hearing loss.Method:The vestibular function of 79 patients with severe hearing loss was examined by video-nystagmography (VNG) and vestibular evoked myogenic potential (VEMP).Result:There were significant differences between the two test outcomes (P<0.01) in the severe group (27 cases). The effective rate of both VNG and VEMP normal group was 100%, the effective rate that both VNG and VEMP were abnormal was 41.7%. In the profound severe group (52 cases) there was also a significant difference between the two test results and the therapeutic effect (P<0.01). The effective rate of both VNG and VEMP normal group was 76.9%. The effective rate was 34.6% with both VNG and VEMP abnormal. There was no significant difference between hearing loss degree and curative effect.Conclusion:The VNG and VEMP examinations in patients with severe sudden hearing loss are valuable in evaluating the efficacy. Both VNG and VEMP were abnormal with the worst curative effect.

Estudio del daño otolítico en pacientes con vértigo posicional paroxístico benigno mediante potenciales vestibulares miogénicos evocados

IntroductionBenign paroxysmal positional vertigo (BPPV) pathophysiology is based on otoconia migration from the utricle and saccule to the semicircular canals, however, the role of the saccule is still under study. Our aim is to study the otolith damage in these patients with vestibular evoked myogenic potentials (VEMPS) and correlate the results with those of computerised dynamic posturography (CDP). Material and methodsWe present 79 patients diagnosed with BPPV between March and June 2017. VEMPS and CDP studies were performed. We selected 67 patients with posterior semi-circular canal BPPV and we compared them with 60 healthy subjects. ResultsBPPV group had abnormal cervical VEMPS in 49.25% of patients compared to 16.67% in the control group. Ocular VEMPS were altered in 61.19% of the patients and 6.67% of the healthy subjects. Abnormal ocular VEMPS in patients with recurrent BPPV was statistically significant. There was no significant correlation with CDP results. ConclusionsUtricular and saccular dysfunction in BPPV patients proved by VEMPS is higher than in healthy individuals. This result may be related to symptoms of instability experienced by these patients occasionally.

Cervical vestibular-evoked myogenic potentials in patients with multiple sclerosis: sensitive in detecting brainstem involvement?

Cervical vestibular-evoked myogenic potentials (cVEMPs) are accepted to demonstrate the vestibulo-collic reflex. However, the brainstem pathway is still not fully understood. The aim of the study was to evaluate the contribution of cVEMPs to detection of brainstem involvement in multiple sclerosis (MS). Thirty patients fulfilling the criteria for definite MS were included in the study. All were newly diagnosed cases, admitted due to an attack with active lesions on MRI. Thirty-one age- and sex-matched healthy controls constituted the control group. The latencies of peaks p13 and n23 and peak-to-peak amplitude of p13-n23 were measured. Brainstem lesions on MRI were present in 13 of the patients (43.4%). Comparison of the overall results recorded from patients with the healthy controls did not reveal a statistically significant difference in any of the parameters studied (p > 0.05). A significant inter-side difference was not also present between groups (p > 0.05). When p13 and n23 latencies exceeding 2.5 standard deviations (SD) were taken into consideration, it was seen that there were seven patients (23.3%) with prolonged latencies mainly involving the p13 peak. Five of them had brainstem signs on examination and had brainstem lesions on MRI. In the other eight patients with abnormal MRI, normal results were recorded indicating that in only 38% of patients with brainstem lesions, cVEMPs were altered. Absence of a correlation between cVEMPs and brainstem clinical or MRI lesions defies their role in identifying lower brainstem involvement.

EP 140. Vestibular evoked myogenic potentials: A retrospective analysis

Diagnostic testing of the vestibular system is an integral part of assessment of patients with balance dysfunction. Rediscovery of Vestibular Evoked Myogenic Potentials (VEMP) has introduced a new dimension to vestibular assessment, especially otolith function. We present a retrospective analysis of both C-VEMP and O-VEMP in neurologic & otologic conditions. Data collated retrospectively from records of 98 patients referred for diagnostic VEMP testing to the Electrophysiology laboratory. Presenting symptoms were imbalance and giddiness. 45 male and 53 female patients in the age range of 17–79 years. 38 had Benign Paroxysmal Positional Vertigo (BPPV), 12 Acute Vestibular Neuronitis, 11 Meniere’s Disease, 7 Chronic Otitis Media ( 3 right, 2 left and 2 bilateral ). 1 was referred to confirm left Superior Canalicular Dehiscence, 9 Parkinson Disease, 1 ProgressiveSupranuclearPalsy and 4 Multiple Sclerosis. 15 remained unclassifiable and were categorised as Vertigo Not Otherwise Specified (NOS). Cervical and Ocular VEMP were performed on both ears on all the patients with Medicaid EP machine. Testing done in one session lasting about 30 minutes for each patient. Rest periods given between sets to prevent muscle fatigue. Cervical VEMP: active recording electrodes on Sternocleidomastoid belly ipsilateral to auditory stimuli. Reference on the manubrium sterni. Patients instructed to raise the head about 30 degrees above the bed and hold it actively at that level . Ocular VEMP: recording electrodes were placed contralaterally, active 1 cm inferior to lower eyelid and reference, 2 cm below that. Maximum upgaze was encouraged during testing. Ground electrode: forehead for both tests. Stimulation Parameters: Rarefaction clicks: 100 microsec duration, 5 Hz frequency , intensity 120–125 dB nHL, headphones. Recording Parameters: Filters: Low frequency filter- 20 Hz, High frequency filter- 3 KHz. Sweep: 10 msec/divn. Total sweep of 100 msec. Gain: 100 microvolts /divn. Notch: None. Averages: 100/set, 2 sets for each test. Parameters analysed : Latencies of P13, N23 and amplitude of cervical VEMP on both sides. Latencies of N10, P16 and amplitude of ocular VEMP on both sides. Comparison against normative values and two tailed t test with unequal variance were performed to look for statistically significant deviation in each subgroup of diseases. There was no statistically significant difference in latencies and amplitudes of cervical (p = 0.39 and 0.28 for left and right respectively ) and ocular VEMP (p = 0.4 and 0.64 for left and right respectively) in BPPV. In some patients with Acute Vestibular Neuronitis cervical and ocular responses were absent. Very significant difference in latencies and amplitudes (p < 0.01 on left, p < 0.001 bilaterally) were noted. In Meniere’s disease, p values < 0.01 were obtained uniformly for both cervical and ocular VEMP. p < 0.001 for cervical and ocular VEMP in Otitis Media except the left ocular VEMP which trended the disease. PD and PSP group showed statistically significant differences in cervical and ocular VEMP latencies and amplitudes (p < 0.01). Number of patients with Multiple Sclerosis is small and the results are inconclusive. In the sole patient with left Superior canal dehiscence, the cervical and ocular VEMP were larger than normal ( more than twice in amplitude as against average for the age) on the left thus underscoring its use in this condition. 15 patients had imbalance and giddiness, but not diagnosed with a CNS, PNS or vestibular disorder. Interestingly the Cervical VEMP was significantly abnormal (p < 0.001) but the Ocular VEMP did not show statistically significant deviation in latency or amplitude. This suggests a dichotomy between saccular & utricular pathology, the former being responsible for the patients symptoms. This is, to the best of our knowledge the first report of abnormalities of both Cervical and Ocular VEMP in patients with neurologic and neurootologic disorders from India. The role of VEMPs in studying degenerative neurological disorders (PD and PSP) with imbalance and falls has been explored and since abnormalities in both cervical and ocular VEMPs are noted,suggesting a role for the vestibular system and central connections in imbalance & loss of posture in these conditions. Role of VEMP in MS is routinely mentioned, but it is at best an adjunct diagnostic procedure. The lack of usefulness of VEMP in BPPV has been underscored by this study. But it may be useful in acute attacks of Meniere’s disease and Acute Vestibular Neuronitis to guage the extent and laterality of damage, especially since these disorders are bilateral.Our findings suggest that Ocular VEMP is more sensitive than Cervical VEMP in Vestibular Neuronitis. In chronic otitis media VEMPs are abnormal and can be useful to evaluate integrity of labyrinthine function. The main drawback is the paucity of numbers in different categories. Based on these findings we propose to enrol more patients, especially in the neurological subsets prospectively to elucidate the role of VEMP.

Abnormalities of vestibular-evoked myogenic potentials in idiopathic Parkinson's disease are associated with clinical evidence of brainstem involvement.

Brainstem degeneration in Parkinson's disease (PD) may explain the occurrence of many non-motor symptoms in this condition. Purposes of the present work were to investigate brainstem function in PD through a battery of vestibular-evoked myogenic potentials (VEMP) allowing a comprehensive brainstem exploration and to correlate VEMP findings with symptoms related to brainstem involvement. Cervical (cVEMP), masseter (mVEMP) and ocular (oVEMP) VEMPs were investigated in 24 PD patients and compared with those recorded in 24 age-matched controls. Presence of symptoms ascribable to brainstem dysfunction, such as daytime sleepiness, REM sleep behavior disorder and depression, was investigated through Epworth Sleepiness Scale, Parkinson's Disease Sleep Scale, REM Sleep Disorder Screening Questionnaire (RBD-SQ) and Geriatric Depression Scale. Postural instability was additionally assessed through mini-BESTest. The frequency of alteration of VEMPs in patients was 83.3 % when considering the whole set and 41.7 % for cVEMP, 66.7 % for mVEMP and 45.8 % for oVEMP. This was significantly different from controls, with absence being the prevalent alteration in PD. A significant inverse correlation between the number of altered VEMPs and mini-BESTest and a direct correlation with RBD-SQ were found. The VEMP battery under study allowed the identification of brainstem dysfunctions in PD patients, which correlated with clinical tests suggestive of postural and REM sleep disorders. VEMPs might represent a valuable tool of brainstem assessment in PD.

The Clinical Utility of Vestibular Evoked Myogenic Potentials in Patients of Benign Paroxysmal Positional Vertigo.

Vestibular Evoked Myogenic Potentials (VEMP) is an emerging tool to diagnose Benign Paroxysmal Positional Vertigo (BPPV). The clinical utility of VEMP has been reported only in small accord in Indian literature. To study the latency and amplitude of VEMP in patients with BPPV and compare it with that of normal subjects. The study included two groups. Group one (control group) were 18 normal subjects. Group two (test group) were 15 subjects with unilateral BPPV. Those subjects who fulfilled the selection criteria based on case history and audiological assessment were taken for the VEMP recording. The VEMP response consist of positive and negative successive waves (pI-nI), with latency values in adults about 13 and 23 milliseconds respectively. Data was analysed using Statistical Package for Social Sciences (SPSS) version 12 (Chicago, IL, USA). Unpaired t-test was employed to measure the statistical difference between control group and test group. The difference in n23 and the peak to peak amplitude between the ipsilateral and contralateral ears of the test group were statistically significant, whereas such a difference in the p13 latency turned out to be statistically insignificant. It should be noted that, out of 15 patients in the test group, five patients showed only artifact tracer recordings in both the ears which is considered as no response. The heterogeneity of the results extended from absence of VEMP to prolongation of both p13, n23; prolongation of p13 alone; and even side to side variations. Absent response from the ipsilateral ear, prolonged latency of n23 and decreased peak to peak amplitude (p13, n23), indicates the disease pathology. However, large sample size is required to draw further conclusions and to consolidate the usage of VEMP in the diagnosis of BPPV.

An analysis of vestibular evoked myogenic potentials in patients with benign paroxysmal positional vertigo.

Vestibular evoked myogenic potentials (VEMPs) selectively test the vestibular end-organ. The aim of this study was to analyze how the site of the diseased canal, type of particulate deposition, duration of symptoms, severity of nystagmus, recurrence, and age affect the VEMP in patients with benign paroxysmal positional vertigo (BPPV). One hundred two patients were enrolled in the study between 2009 and 2012. There were 36 men and 66 women with ages ranging from 16 to 71 years (mean age, 42.28 ± 11.29 years). Patients with BPPV were tested with roll-on and head-hanging maneuvers under video-electronystagmography monitoring and with air conduction cervical VEMP testing. Patients were grouped for duration, severity, recurrence, age, site of canal involvement, and so on, and the results were compared in each subgroup. Kruskal-Wallis and Mann-Whitney U tests were used for the comparative analysis. Twenty-four patients (23.5%) had a gross VEMP abnormality (absence of VEMP in 6 and greater than 25% depression of the amplitude in 18). Abnormality of VEMPs was not correlated with factors including age, severity of nystagmus, number of maneuvers applied, and the site of canal involvement (P < .05). However, persistence or recurrence of symptoms has an effect on VEMP results (P = .016). Vestibular evoked myogenic potential is a useful tool to study the otolithic function in patients with BPPV and should be included in the test battery.