Does blindness affect ocular vestibular evoked myogenic potentials?

Objective

The aim of the present study was to investigate the influence of blindness on ocular vestibular evoked myogenic potentials (oVEMP) responses.

Asymmetric vestibular evoked myogenic potentials in unilateral Menière patients

Vestibular evoked myogenic potentials (VEMPs) were measured in 22 unilateral Menière patients with monaural and binaural stimulation with 250 and 500 Hz tone bursts. For all measurement situations significantly lower VEMP amplitudes were on average measured at the affected side compared to the unaffected side. Unilateral Menière patients have, in contrast to normal subjects, asymmetric VEMPs, indicating a permanently affected vestibular (most likely otolith) system at the side of hearing loss. The diagnostic value of VEMP amplitude asymmetry measurement in individual patients is low, because of the large overlap of the VEMP amplitude asymmetry range for unilateral Menière patients with that for normal subjects.     

Auditory pathways’ maturation after cochlear implant via cortical auditory evoked potentials ,

Introduction: Evaluation of cortical auditory evoked potentials in children with cochlear implants has been proven to be an effective method for assessing cortical maturation after electrical stimulation.Objective: To analyze the changes in latency values of cortical auditory evoked potentials before and three months after cochlear implant use.Material and methods: This was a case-control study with a group of five children using cochlear implant awaiting activation of the electrodes, and a control group composed of five normal-hearing children. Auditory electrophysiological assessment was performed by the testing of the cortical auditory evoked potentials at two different periods: prior to cochlear implant activation and after three months of cochlear implant use.Results: A significant decrease in the latency time of the P1 component was observed after three months of stimulation via cochlear implant, whose values were higher than those from the control group. The younger the child was at electrode activation, the greater the reduction in latency of the P1 component.Conclusion: Changes in the characteristics of cortical auditory evoked potentials can be observed in children who receive cochlear implants; these changes are related to the age of intervention, suggesting a rapid maturation of the auditory pathways after electrical stimulation.© 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.     

Cervical vestibular evoked myogenic potentials and video head impulse test in Ménière disease

IntroductionMénière's disease is among the most frequent causes of vestibular disorders. Although it is a clinical diagnosis, a better understanding of the pathophysiology and clinical course of the disease through tests would allow improvement in the prognosis and more effective treatments.ObjectivesTo describe the results of the cervical vestibular evoked myogenic and video head impulse test in patients with a defined diagnosis of Ménière's disease and to correlate them with disease duration.MethodsThe sample consisted of 50 participants, of whom 29 comprised the study group and 21 the control group. The individuals were submitted to a questionnaire, otoscopy, audiometry and vestibular function assessment through the cervical vestibular evoked myogenic potential and video head impulse test.ResultsFor the video head impulse test, lateral canal gain values below 0.77 were considered abnormal and for the vertical channels, below 0.61. The percentages of normality were 82.76% for lateral, 89.65% for posterior and 91.37% for anterior canals. For the cervical vestibular evoked myogenic potential, the upper limits of normal for latencies were defined as 18.07 ms for p13 and 28.47 ms for n23; and in the SG, 19.57% showed prolongation of latency of p13 and 4.35% of wave n23, whereas 18.96% did not show biphasic potential.ConclusionsFor the video head impulse test, a decreased gain of the vestibulo-ocular reflex for the lateral canal was observed, with a higher incidence of overt type corrective saccades compared to the control group. For the cervical vestibular evoked myogenic potential, there was a significant difference between the groups for the inter-amplitude parameter, including for asymptomatic ears. There was no correlation between the results of the tests and disease duration.     

Vestibular evoked myogenic potentials show altered tuning in patients with Ménière's disease.

OBJECTIVE: Acoustic stimulation of the saccule gives rise to a vestibulocollic reflex, the output of which can be measured in the neck as inhibition of activity in the ipsilateral sternocleidomastoid muscle. This vestibular evoked myogenic potential has been promoted as a means of assessing integrity of saccular function. In this study, we test the hypothesis that the cochleosaccular hydrops of Ménière's syndrome leads to alterations in saccular motion that change the dynamics of the vestibular evoked myogenic potential. STUDY DESIGN: Prospective cohort study. SETTING: Large specialty hospital, department of otolaryngology. SUBJECTS: Fourteen normal adult volunteers and 34 consecutive consenting adult patients with unilateral Ménière's disease by American Academy of Otolaryngology-Head and Neck Surgery diagnostic criteria. INTERVENTIONS: All subjects underwent vestibular evoked myogenic potential testing using ipsilateral broadband click and short tone-burst stimuli at 250, 500, 1,000, 2,000, and 4,000 Hz. MAIN OUTCOME MEASURES: Threshold, amplitude, and latency of vestibular evoked myogenic potential responses in normal and Ménière's affected and unaffected ears. RESULTS: Vestibular evoked myogenic potential was present in all ears tested. Normal subjects show a frequency-dependent vestibular evoked myogenic potential threshold, with best response ("frequency tuning") at 500 Hz. Compared with normal subjects and unaffected ears of Ménière's subjects, affected Ménière's ears had significantly increased vestibular evoked myogenic potential thresholds. Affected Ménière's ears showed threshold shifts at all frequencies and there was less tuning apparent at 500 Hz. Unaffected ears of Ménière's subjects also showed significantly elevated vestibular evoked myogenic potential thresholds compared with normal subjects. Analyses of vestibular evoked myogenic potential thresholds for effects of age, hearing loss, and audiometric configuration showed no significant differences. CONCLUSIONS: Ménière's ears display alterations in vestibular evoked myogenic potential threshold and tuning, supporting our hypothesis of altered saccular motion mechanics arising from hydropic distention. Unaffected ears of unilateral Ménière's subjects show similar changes, though to a lesser degree. This finding may be because of occult saccular hydrops in the asymptomatic ear or binaural interactions in the vestibular evoked myogenic potential otolith-cervical reflex arc.     

Tone burst vestibular evoked myogenic potentials: diagnostic criteria in patients with Ménière's disease

Conclusion: We suggest that 1/0.5 kHz FPA would be clinically useful in the diagnosis of Ménière's disease. Objective: To determine whether clinically useful VEMP parameters could be identified using different tone burst stimuli for the diagnosis of Ménière's disease. Subjects and methods: The Ménière's group included 24 affected ears from definite Ménière's disease and 26 affected ears from probable Ménière's disease. The control group included 20 normal ears. Using tone bursts of 0.5 and 1 kHz, two parameters were examined: 1) the frequency peak amplitude ratio (1/0.5 kHz FPA), where the peak amplitude was determined by the difference in amplitude between peak p13 and peak n23 ipsilaterally; and 2) the interaural amplitude difference (IAD) ratio, defined as the difference in amplitude between peaks p13 and n23 (p13–n23) in the right and left ears divided by the sum of p13–p23 in both ears. Results: Data showed that the 1/0.5 kHz FPA ratios in the Ménière's group were significantly elevated compared with those of the control group (p<0.001) and the recommendable cut-off value for the diagnosis of Ménière's symptoms using 1/0.5 kHz FPA was > 0.7. However, the IAD ratio did not show significant differences in either the 0.5 or 1 kHz stimulus conditions.     

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.     

Glycerol affects vestibular-evoked myogenic potentials and pure-tone hearing in patients with Ménière’s disease

Conclusion: The pure-tone audiometry results following glycerol administration indicated a positive effect on cochlear endolymphatic hydrops. Glycerol cervical vestibular-evoked myogenic potential (cVEMP) tests are a useful means of diagnosing saccular hydrops. There was no correlation between cVEMP and audiological results. Objective: To document the changes in pure-tone hearing outcomes and cVEMPs in patients with Ménière’s disease (MD) and 10 healthy volunteers before and after oral administration of glycerol. Methods: Twenty-nine study group subjects were chosen with complaints of vertigo. cVEMP testing and pure-tone hearing level testing were performed before and at 1, 2, and 3 h after administration of glycerol. Results: The means of the latencies, amplitudes, and difference ratio in 20 normal subject ears were determined. Based on these values, 9/29 MD-affected (MDA) ears (31%) had a unilaterally absent cVEMP. Compared with difference ratio values of the control groups there were significant differences in both latencies and amplitudes in MDA ears after glycerol administration. Before glycerol administration, there were significant differences between control and MDA ears on mean values of pure-tone hearing outcomes. Twenty patients in the MDA group showed significant pure-tone hearing outcomes after glycerol administration.     

A saccular origin of frequency tuning in myogenic vestibular evoked potentials?: implications for human responses to loud sounds

Previous research has indicated that an early component of click-evoked myogenic potentials in the sternocleidomastoid muscle is vestibularly mediated, since it can be obtained in subjects with loss of cochlear function, but is absent in subjects with loss of vestibular function (Colebatch et al., 1994). We report here the results of an experiment to investigate whether this response shows any tuning properties. In a sample of 11 subjects, we obtained acoustically evoked EMG from the sternocleidomastoid muscle in response to 110 dB SPL 10 ms tone pips with frequencies of 100 Hz, 200 Hz, 400 Hz, 800 Hz, 1600 Hz and 3200 Hz. The results of this experiment indicate that this response does indeed have a well-defined frequency tuning which may be modelled as a resonance with a maximum response at frequencies between 300-350 Hz. The possible saccular origin of the tuning response and the consequences that this may have in human responses to loud sounds is discussed. Also discussed are the consequences of particular electrode arrangements in relation to the innervation and anatomy of sternocleidomastoid.     

Impact of subject’s position and acoustic stimulus type on vestibular evoked myogenic potentials (VEMPs) in normal subjects

Vestibular evoked myogenic potentials (VEMPs) are currently considered a diagnostic tool for studying the vestibular system, specifically the saccule and inferior vestibular nerve. This prospective study aimed at evaluating the impact of patient position and type of acoustic stimulus on VEMPs results using 60 healthy subjects who underwent otoscopy, pure tone audiometry and VEMPs in different conditions affecting their position and the type of acoustic stimulus. Corrected amplitude is significantly greater when the patient is seated and latency difference and amplitude asymmetry do not change with either patient position or type of stimulus. The results obtained in different test conditions are not comparable. Being seated is the most appropriate position for the test.     

Ocular vestibular evoked myogenic potentials: frequency tuning to air-conducted acoustic stimuli in healthy subjects and Ménière's disease

Ocular vestibular evoked myogenic potentials (oVEMP) in response to 250-, 500- and 1000-Hz air-conducted short tone bursts were studied in 22 healthy subjects and 37 Ménière's disease patients. The goal of this study was to investigate normal tuning characteristics of the oVEMP and the possible oVEMP changes with respect to frequency dependence in Ménière's disease. In unilateral Ménière's disease patients, a distinction was made between affected ears and unaffected ears. It was found that in normal subjects, the oVEMP tunes to a stimulus frequency of 500 Hz, with the highest amplitude and lowest threshold at this particular frequency. Generally, Ménière's disease patients showed lower amplitudes and higher thresholds than normal subjects at all 3 stimulus frequencies in both the affected and the unaffected ear. Additionally, for ears affected by Ménière's disease, the best stimulus frequency was 1000 Hz. With the use of this altered tuning for these ears, we tried to find a criterion for distinguishing normal from Ménière's disease ears.     

High click stimulus repetition rate in the auditory evoked potentials in multiple sclerosis patients with normal MRI. Does it improve diagnosis?

OBJECTIVE: The purpose of this study was to evaluate whether auditory brainstem responses (ABR) in multiple sclerosis (MS) patients were qualitatively different from a normal population. MATERIAL AND METHOD: This study analysed 69 subjects, separated into two groups; a control group composed of 20 females and 20 males; and an MS group composed of 20 females and 9 males. The controls had no history of neurological or otorhinolaryngological disorders. All MS patients presented a normal magnetic resonance imaging of the brainstem. A definite diagnosis of MS was given according to Poser's criteria for MS research protocols (1983). The following parameters were used in the study of the ABR of each subject: 2000 clicks of 100 ms at 60 dB equivalent peak of sou nd pressure level (pe SPL) above the psycho-acoustic threshold, obtained with the subject's response to clicks. Both ears were initially stimulated at 11 clicks/s, and then with clicks of same intensity, but with a progressive increase of the stimulus rate to 31, 51, 61 and 71 clicks/s. The analysis of variance with independent factors and repeated measures was used in the statistical analysis of the comparison between group results. RESULTS: The absolute latency of wave III was statistically greater, with a stimulus rate of 51 and 61 clicks/s, in the MS group. The males in the MS group presented a statistically greater absolute latency of wave V with the use of 51 and 61 clicks/s. With stimulus rates above 30 clicks/s, the absolute latency of wave V was also greater for MS females. There were statistically significant differences in the interpeak interval I - III of the control group compared to the MS group, for stimulus rates of 51 and 61 clicks/s, in females and for the stimulus rate of 61 clicks/s in males. This interval was higher in the MS group with these stimulus rates. CONCLUSION: The results suggest the inclusion of stimulus rates of 51 and 61 clicks/s in the ABR tests of subjects with clinical suspicion of demyelinating diseases like MS.     

Comparing the sensitivity and specificity of cervical vestibular-evoked myogenic potentials and electrocochleography in the diagnosis of Ménière’s disease

Abstract

Objective: To compare the sensitivity and specificity of objective cervical vestibular-evoked myogenic potential (cVEMP) tuning curves and electrocochleography (ECochG) for the diagnosis of Ménière’s disease (MD).

Design: Sensitivity and specificity were calculated from 95% normative ranges of 500?Hz cVEMP threshold and ECochG SP/AP amplitude ratios.

Measures: Extra-tympanic ECochG testing to 90?dB nHL clicks and cVEMP threshold tuning curves (250–1000?Hz).

Study sample: We tested 15 patients (30 ears) diagnosed with definite bilateral MD based on the clinical criteria proposed by the American Academy of Otolaryngology Head and Neck surgery, 1995 (assumed gold standard) and 20 controls.

Results: 500?Hz cVEMP threshold was the most promising parameter to differentiate MD ears from controls. cVEMP and ECochG showed high specificity (83.3 and 100%, respectively) and low to moderate sensitivity (22.2 and 71.4%) for long term MD. ECochG sensitivity increased to 89% during a symptomatic period, compared to 33% for cVEMP. However, ECochG can be difficult to schedule during symptomatic periods. Sensitivity of cVEMP for the diagnosis of MD appears limited.

Conclusions: ECochG has higher sensitivity than cVEMP in the diagnosis of Ménière’s patients, but the ECochG SP/AP amplitude ratio measure is not perfect for the diagnosis of MD.     

The relationship between cortical auditory evoked potentials (CAEPs) and speech perception in children with Nurotron® cochlear implants during four years of follow-up

ObjectiveThe purpose of the current study was to evaluate the relationship between the presence or absence of cortical auditory evoked potentials (CAEPs) to speech stimuli and the performance of speech perception in Chinese pediatric recipients of the Nurotron^® cochlear implant (CI).We also wanted to determine how the CAEPs might be used as an indicator for predicting early speech perception and could provide objective evidence for clinical applications of CAEPs.Methods23 pediatric unilateral CI recipients participated in this study. 15 males 8 females, and their ages at implantation ranged from 13 to 68 months, with a mean age of 36 months. CAEPs and Mandarin Early Speech Perception (MESP) tests were used to evaluate the audibility and speech perception of these CI users. The tests were administered at the first, second, third, and fourth year after the CI surgery.ResultsAll the subjects demonstrated improvements in detection of speech sounds with CI. The percentages of participants who could detect all three stimuli were 26% (6/23) at first year, to 100% (23/23) at the fourth year post-implantation. The percentages of participants who passed the Category 6 of MESP were from 9% (2/23) at first year, to 91% (21/23) at the fourth year post-implantation. Significant correlations (p < 0.05) were found between CAEP scores and MESP at the first, second, third year after the CI surgery. The multiple regression equation for prediction of MESP categories from CAEP scores and hearing ages was MESP = 1.088 + (0.504 × CAEP score) + (0.964 × hearing ages) (F = 72.919, p < 0.001, R² = 0.621).ConclusionThe results of this study suggested that aided cortical assessment was a useful tool to evaluate the outcomes of cochlear implantation. Cortical outcomes had a significant positive relationship with the MESP, which predicted the early speech perception of CI recipients.