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1.
Background: Characteristics of vestibular evoked myogenic potentials (VEMPs) depend on stimulus conditions. Objective: To determine the optimal stimulus conditions for cervical and ocular VEMPs. Methods: Participants were 23 healthy subjects. We compared air-conducted cervical and ocular VEMPs elicited by various tone-burst conditions (frequencies 500–1,000?Hz, rise/fall times 1–2?ms, and plateau times 0–6?ms) with an intensity of 105?dB normal hearing level. Effects of simultaneous contralateral masking noise on VEMPs were also evaluated. Results: The largest cervical VEMP amplitudes were elicited by 500–750?Hz and 2–6?ms plateau time-tone-bursts, and the largest ocular VEMP amplitudes by 750?Hz and 2–4?ms plateau time-tone-bursts. Repeatability of the latency was better at 1?ms than at 2?ms rise/fall time in both VEMPs. In both VEMPs, masking noise reduced amplitude, and in ocular VEMP, amplitudes were significantly larger at the left ear stimulation than the right. Conclusion: Optimal tone-burst stimulation for both VEMPs seemed to be 500–750?Hz frequency and 1/2/1?ms rise/plateau/fall time without contralateral masking noise. Ocular VEMP amplitudes from left ear stimulation were originally larger than those from right ear stimulation. 相似文献
2.
AbstractObjective: The vestibular evoked myogenic potential (VEMP) is associated with otolithic afferents and can be used to evaluate the function of the saccule and utricle. In this study, we compared cervical VEMP evoked by stimulation with Air-conducted sound (ACS) and bone-conducted vibration (BCV) to the forehead and investigated whether BCV can be used as a substitute for ACS. Methods: Data were obtained from 33 patients with vestibular schwannoma. Vestibular examinations were performed preoperatively. VEMP was obtained upon stimulation with ACS (ACS cVEMP) and BCV to the forehead using a minishaker (BCV cVEMP). Vestibular function was also analyzed using the caloric test and ocular VEMP (oVEMP) testing. oVEMP was measured using bone-conductive vibration to the forehead. The results of BCV cVEMP, ACS cVEMP, and oVEMP were compared by the caloric test. Results: Rates of patients with abnormal ACS cVEMP, BCV cVEMP, oVEMP, and caloric test results were 78.8%, 75.8%, 78.8%, and 69.7%, respectively. BCV cVEMP did not correlate with ACS cVEMP, but correlated with oVEMP and caloric test results. Conclusion: BCV cVEMP did not correlate with ACS cVEMP. Therefore, BCV cVEMP cannot be used as a substitute for ACS cVEMP. 相似文献
3.
Conclusion: Like NAC ameliorates hearing loss from acoustic trauma in the inner ear, NAC may also rescue hearing loss from sudden deafness confined to the inner ear. Objective: This study assesses the effect of N-acetyl-L-cysteine (NAC) as a single therapy for sudden deafness. Methods: Thirty-five sudden deafness patients with neither systemic disorders nor central signs in electronystagmography were treated with NAC alone and assigned to Group A. For comparison, another 35 sudden deafness patients treated by corticosteroids and plasma expander were assigned to Group B. There were no significant differences between the two groups in terms of age, sex, laterality, and pre-treatment mean hearing level. All patients underwent an inner ear test battery comprising audiometry, and ocular vestibular-evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and caloric tests. Results: Groups A and B did not significantly differ in the pre-treatment mean hearing level, and percentages of abnormal oVEMP, cVEMP, and caloric tests, indicating that the involvement severity of sudden deafness between the two groups was similar. However, Group A (43?±?27?dB) showed significantly greater mean hearing gain than Group B (21?±?28?dB), and Group A (91%) revealed better improved rate of hearing than Group B (57%). 相似文献
4.
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. 相似文献
5.
Objectives: The benefit of using the electroacoustic functionality was tested compared to electric stimulation alone. Two different cut-off frequencies between acoustic and electric stimulation were tried. Methods: Performance and subjective preference in 10 subjects was measured with electric only and electroacoustic stimulation with two settings: a cut-off for acoustic amplification at the frequency where thresholds exceeded 70 dB and 85 dB. An overlapping setting was also tried in five participants. Results: There was a non-significant trend with a median improvement in SRT of 1.3?dB (70?dB cut-off) and 0.8?dB (85?dB cut-off) compared to the electric only condition. From nine subjects who completed the study, one preferred the 85?dB cut-off frequency, with the others preferred either a 70?dB cut-off or an overlapping setting. Discussion: Nine subjects continued to use the EAS processor after study termination because of subjective benefits. The variability in speech outcomes and subjective preference is underlining the importance of being able to manually change acoustic and electric cut-off frequencies. Conclusion: There were non-significant median group benefits from use of the acoustic component for these existing CI users. A hearing loss of 70?dB HL is an appropriate default cut-off frequency in the fitting software. 相似文献
6.
Objectives: To optimize patient’s maps in Electric Acoustic Stimulation (EAS) users based on the degree of post-operative aided hearing thresholds. Methods: Twenty-one adult EAS patients participated in this study. Patients were subdivided into three groups, based on their unaided hearing threshold: (1) electric complementary (EC, n?=?6) patients with ≤30?dB HL at 125–500?Hz with severe to profound hearing loss at higher frequencies who only use electric stimulation, (2) EAS ( n?=?8) patients with 30–70?dB HL from 125 to 250?Hz and profound hearing loss in high frequencies who use combined EAS, and (3) Marginal-EAS (M-EAS, n?=?7) patients with 70–95?dB HL at frequencies ≤250?Hz who use combined EAS. Sentence perception in noise, melodic contour identification, and subjective preference were measured using Full Overlap, Narrow Overlap, Gap, and Meet maps. Result: Of the 21 patients that participated, 12 subjects were classified as complete hearing preservation and 9 subjects were classified as partial hearing preservation. The highest performing maps in sentence-in-noise perception and melodic contour identification were Gap, Meet, and Full Overlap for the EC, EAS, and the M-EAS groups, respectively. These results are consistently across different test materials and align with subject preference as well. Conclusion: These results suggest that clinical fitting in EAS listening should be individually tailored. EAS performance can be enhanced by optimizing maps between acoustic and electric stimulation based on the degree of aided hearing thresholds. 相似文献
7.
Objective: The presence of endolymphatic hydrops can be suggested by improving the amplitude of vestibular-evoked myogenic potential (VEMP) after furosemide administration (furosemide loading VEMP [FVEMP]). The authors aimed to determine a stimulation frequency and judgment criteria to ascertain whether a revised FVEMP protocol can be applied to clinical settings. Methods: The study included 25 individuals with unilateral Meniere’s disease (MD) and 11 normal healthy volunteers. Normalized amplitude of VEMP, using a tone burst sound at 250, 500, 700, 1000, 1500 and 2000?Hz, was measured before and after furosemide administration in the two groups. Improvement ratio (IR) of amplitude was calculated at each frequency. Results: There were no significant differences in IR between the control group and the MD group at each frequency, except at 500?Hz. Receiver operating characteristic curve analysis revealed an IR cut-off value of 14.2% at 500?Hz, with a sensitivity of 0.706 and a specificity of 0.810. Conclusions: The revised FVEMP protocol using a 500?Hz tone burst stimulus and normalized amplitudes was defined as positive when IR exceeded 14.2% or when a biphasic wave could be detected after furosemide administration in cases without a detectable biphasic wave before administration. 相似文献
8.
Conclusions: Vestibular function disorders were widespread among nasopharyngeal carcinoma (NPC) patients. The radiation doses to the inner ears were associated with the incidence of vestibular function disorders, but the correlations were mild. The inflammatory responses and possible resolution obstacles of inflammation participated in persistent vestibular function disorders after irradiation. Objectives: To investigate the incidence of vestibular function disorders in NPC patients after irradiation and potential mechanisms. Methods: Patients who received radical intensity-modulated radiotherapy for their NPC were recruited. The serum levels of IL-6 and IL-17 were detected by ELISA method. Vestibular evoked myogenic potential (VEMP) tests were used to evaluate vestibular function and correlation analyses were used to analyze the potential mechanisms of vestibular function disorders. Results: Thirty-eight patients were included. The incidences of abnormal ocular VEMP (oVEMP) and cervical VEMP (cVEMP) were 65.79% and 80.26% at the time of completion of radiotherapy, and 61.84% and 71.05% at 3 months after radiotherapy. The mean and maximum radiation doses to the inner ears were both significantly associated with abnormal oVEMP and cVEMP ( p?0.05, all), but the correlations were all mild. The serum levels of IL-6 and IL-17 were both significantly associated with abnormal oVEMP and cVEMP after irradiation ( p?0.05, all). 相似文献
9.
AbstractObjective: Inconsistencies regarding frequency tuning of ocular vestibular evoked myogenic potentials (oVEMP) prompted the present study to aim at characterizing frequency tuning of oVEMP in healthy individuals. Design: Normative study. Study sample: The study was conducted to obtain oVEMP responses from 54 healthy individuals in age range of 18–30 years. The responses were acquired for tone-bursts at octave and mid-octave frequencies from 250 to 2000 Hz from the inferior oblique muscle using contralateral electrode placement. The frequencies were compared for amplitude and threshold. Results: oVEMPs were present in 100% of individuals at or below the frequency of 1000 Hz. The responses had maximum amplitude and lowest thresholds at 500 Hz. There were at least two replicable peak-complexes namely n1-p1 and p1-n2. Both these complexes revealed tuning at 500 Hz. Comparison between the two peak-complexes revealed higher amplitudes and lower thresholds for p1-n2 complex. Conclusions: oVEMPs are tuned to 500 Hz for both peak-complexes, with p1-n2 being more robust. Future studies using the threshold of oVEMP may be better suited to use p1-n2 complex for this purpose, provided vestibular origin of the second complex is proved. Additionally, careful use of tuning property is recommended when evaluating pathological conditions. 相似文献
10.
Conclusion The result suggests that patients with idiopathic bilateral vestibulopathy may have nerve lesions when the inferior nerve system is affected, while the inferior vestibular nerve system may be spared. Objective To clarify the lesion site in idiopathic bilateral vestibulopathy, an acquired bilateral vestibulopathy of unknown cause. Material and methods Two 75-year-old males diagnosed with idiopathic bilateral vestibulopathy were enrolled. Both showed absent or highly decreased responses on the caloric test on both sides. They underwent vestibular-evoked myogenic potential (VEMP) testing by means of acoustical and electrical stimulation. As acoustic stimulation, 95 dB nHL clicks and short tone bursts (500 Hz) were presented, while 3 mA (1 ms) short-duration galvanic stimuli were presented as electrical stimulation. Responses were recorded on the sternocleidomastoid muscles. Results Both patients showed unilateral absence of VEMPs with both acoustic and short-duration galvanic stimuli. 相似文献
11.
Sound-evoked vestibular myogenic potentials recorded from the sternocleidomastoid muscles (the cervical vestibular-evoked myogenic potential or cVEMP) and the extraocular muscles (the ocular VEMP or oVEMP) have proven useful in clinical assessment of vestibular function. VEMPs are commonly interpreted as a test of saccular function, based on neurophysiological evidence showing activation of saccular afferents by intense acoustic click stimuli. However, recent neurophysiological studies suggest that the clicks used in clinical VEMP tests activate vestibular end organs other than the saccule. To provide the neural basis for interpreting clinical VEMP testing results, the present study examined the extent to which air-conducted clicks differentially activate the various vestibular end organs at several intensities and durations in Sprague–Dawley rats. Single unit recordings were made from 562 vestibular afferents that innervated the otoliths [inferior branch otolith (IO) and superior branch otolith (SO)], the anterior canal (AC), the horizontal canal (HC), and the posterior canal (PC). Clicks higher than 60 dB SL (re-auditory brainstem response threshold) activated both semicircular canal and otolith organ afferents. Clicks at or below 60 dB SL, however, activated only otolith organ afferents. Longer duration clicks evoked larger responses in AC, HC, and SO afferents, but not in IO afferents. Intra-axonal recording and labeling confirmed that sound sensitive vestibular afferents innervated the horizontal and anterior canal cristae as well as the saccular and utricular maculae. Interestingly, all sound sensitive afferents are calyx-bearing fibers. These results demonstrate stimulus-dependent acoustic activation of both semicircular canals and otolith organs, and suggest that sound activation of vestibular end organs other than the saccule should not be ruled out when designing and interpreting clinical VEMP tests. 相似文献
12.
Background: The pathogenesis of recurrence of traumatic benign paroxysmal positional vertigo (BPPV) is poorly understood by far. Objectives: To evaluate the value of secondary otolith dysfunction using vestibular evoked myogenic potential (VEMP) test in the pathogenesis of recurrence of BPPV after mild traumatic brain injury (mTBI). Material and methods: We reviewed 42 patients with BPPV after mTBI. According to recurrence, patients were divided into two groups. Both cervical VEMP (cVEMP) and ocular VEMP (oVEMP) tests were performed on all of them. Results: We detected abnormal cVEMP responses in four (26.7%) patients in the recurrent BPPV group after mTBI and five (18.5%) patients in the non-recurrent BPPV group after mTBI, and there was no significant difference between both groups. We detected abnormal oVMEP responses in nine (60.0%) patients in the recurrent BPPV group after mTBI and six (22.2%) patients in the non-recurrent BPPV group after mTBI, and there was a significant difference between both groups. Conclusions and significance: Our study shows that oVEMP abnormalities in recurrent BPPV group after mTBI are significantly higher than those in non-recurrent BPPV group after mTBI. Therefore, we can conclude that secondary utricular dysfunction may be a potential pathogenesis of recurrence of traumatic BPPV. 相似文献
13.
Conclusion: vOCR can detect loss of otolith-ocular function without specifying the side of vestibular loss. Since vOCR is measured with a simple head tilt maneuver, it can be potentially used as a bedside clinical test in combination with video head impulse test. Objective: Video-oculography (VOG) goggles are being integrated into the bedside assessment of patients with vestibular disorders. Lacking, however, is a method to evaluate otolith function. This study validated a VOG test for loss of otolith function. Methods: VOG was used to measure ocular counter-roll (vOCR) in 12 healthy controls, 14 patients with unilateral vestibular loss (UVL), and six patients with bilateral vestibular loss (BVL) with a static lateral head tilt of 30°. The results were compared with vestibular evoked myogenic potentials (VEMP), a widely-used laboratory test of otolith function. Results: The average vOCR for healthy controls (4.6°) was significantly different from UVL (2.7°) and BVL (1.6°) patients ( p?0.0001). The vOCR and VEMP measurements were correlated across subjects, especially the click and tap oVEMPs (click oVEMP R?=?0.45, tap oVEMP R?=?0.51; p?0.0003). The receiver operator characteristic (ROC) analysis showed that vOCR and VEMPs detected loss of otolith function equally well. The best threshold for vOCR to detect vestibular loss was at 3°. The vOCR values from the side of vestibular loss and the healthy side were not different in UVL patients (2.53° vs 2.8°; p?=?0.59). 相似文献
14.
AbstractObjective: This study investigated hearing screening tests by using a custom-designed compensated hybrid active noise cancellation (ANC) earphone and compared it with TDH39 and Audiocups audiometric earphones under conditions of quiet, 45?dB HL masking narrowband, wideband speech-shaped, and white noise. Design: The hearing screening tests were conducted to characterise the shifts of screening results under noisy conditions, and real-ear attenuations at thresholds were assessed to quantify real-ear noise reduction performance. Study sample: Twenty-four normal-hearing adults, aged 20–25?years, participated in this study. Results: The ANC earphone exhibited significantly lower/better mean screening results than those of the TDH39 earphone at 250 and 500?Hz and those of the Audiocups earphone at 250?Hz under conditions of narrowband, speech-shaped, and white noise. Compared with the TDH39 earphone at 250 and 500?Hz, applying a hybrid ANC earphone reduced the shifts in screening results by 14.2 and 12.3?dB, respectively, under the narrowband noise condition. Conclusion: This study demonstrated that the compensated hybrid ANC earphone provided lower shifts of screening results than the TDH39 and Audiocups earphones and that it was capable of screening at 250 and 500?Hz from 20?dB HL under 45?dB HL masking narrowband and wideband noise. 相似文献
15.
ObjectiveThe purpose of this study is the identification of susceptible individuals to develop noise induced hearing loss. For it we use the capacity of the transitory otoacoustic emissions (TEOAE) for the identification of functional alterations at different levels from the auditory system Material and methods67 normal hearing subjects have been studied, we have recorded TEOAE in one ear in three different conditions: in normal conditions (SIN register), simultaneously to the stimulation of the contralateral cochlea (EAC register), and after stimulation we can observe (EAIregister). We compare the amplitude of the TEOAE with the SIN and EAC registers to quantity the contralateral suppressor effect, and the SIN and EAI, register to study the auditory fatigue ResultsWe can observe a reduction in the amplitude of the TEOAE obtained by acoustic stimulation of the ipsilateral ear (0.954 dB SPL), or after the ipsilateral acoustic stimulation (0.75 dB SPL), being able to see an inverse correlation between both values ConclusionsThestudy of the TEOAE obtained in different conditions of acoustic stimulation, ipsilateral or contralateral, and the inverse correlation obtained between the magnitude of the auditory fatigue and the contralateral suppresor effect, provides arguments for the identification of individuals susceptible of developing noise induced hearing loss 相似文献
16.
Objective: To produce sound-evoked cervical vestibular evoked myogenic potentials (cVEMPs). These are widely used for the diagnosis of peripheral vestibulopathies and disturbances of the sacculocollic reflexes. The main, sensitive, frequency for eliciting cVEMPs has been shown to be around 500?Hz. Design: Narrow-band chirps in different frequency ranges (middle frequencies of 0.5, 1, 2 and 4?kHz) will be used for sequential and quasi-simultaneous stimulation of the cervical vestibular organ. As benchmarks, peak-to-peak p13 and n23 amplitudes were analysed. Study samples: The pilot study used five normal-hearing subjects (mean age 38.6?years) none of whom have balance disorders. Results: From 40 measurements, p13 and n23 could be identified in a total of 34 detected cVEMPs. As expected, amplitudes were highest at 500?Hz, followed by 1, 2 and 4?kHz. Using the quasi-simultaneous stimulation method led to a slight reduction in cVEMP amplitudes, but these remained in the same order according to magnitude: 0.5, 1, 2 and 4?kHz. Conclusion: Sequential and quasi-simultaneous narrow-band chirps are effective for evoking cVEMPs. High amplitudes contribute to fast identification across an extended frequency range (0.5–4?kHz) and also contribute to a reduction in examination time and overall sound exposure. 相似文献
17.
Objective: This study investigated the influence of pathological eye movements on the recordings of ocular vestibulo-evoked myogenic potential (oVEMP). Methods: Ten patients with pathological eye movements of non-vestibular origin (nine congenital nystagmus and one opsoclonus) who had negative MRI result were assigned to Group A. Another 20 vestibular neuritis (VN) patients with spontaneous nystagmus were assigned to Group B. Both groups underwent audiometry, and caloric, oVEMP and cervical VEMP (cVEMP) tests. Results: In Group A, the caloric, oVEMP and cVEMP tests showed 40%, 55% and 50% abnormalities, respectively. In Group B (VN), caloric, oVEMP and cVEMP tests revealed 100%, 80% and 45% abnormalities on the lesion ears, and 0%, 40% and 0% abnormalities on the healthy (opposite) ears, respectively. The 40% oVEMP abnormality on the healthy ears may be due to recording failure from the presence of spontaneous nystagmus, since five of five VN patients showed normal oVEMPs on the healthy ears, one year after presentation. Conclusions: Presence of pathological eye movements may affect the recordings of oVEMP. Thus, the oVEMP test is recommended to perform after acute vertiginous episode to exclude the influence of pathological eye movements on the oVEMP recordings. 相似文献
18.
AbstractObjective: 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. 相似文献
19.
Objective To analyse the effects of low-frequency loud acoustic stimulation on goal-directed movements involving the arm. Low-frequency sound stimulation impairs eye stability, evokes a subjective tilt of the visual surround in subjects presenting Tullio's phenomenon and induces, in normal subjects, short-latency evoked potentials in the neck and limb muscles. Material and Methods Healthy subjects performed goal-directed movements in the horizontal plane with the right (dominant) arm to a fixed 3°-wide target positioned at an angle of 30°, with the instruction to perform fast and accurate movements to the target and to hold the final position. This fast-pointing task was performed in association with sound-induced vestibular–otolithic stimulation (110 dB SPL, 500 Hz) in the absence of visual guidance (i.e. pointing at a memorized target in the absence of target or pointer cues). Pointing errors were analysed by computing the constant errors made by the subjects (mean error). Pointing errors were also correlated with movement kinematics (movement duration, peak velocity, time to peak velocity) and with the reaction time of movement. Results The low-frequency loud acoustic stimulation modified the final position of the arm-pointing task at the memorized target in the absence of vision. Conclusion Goal-directed movements are achieved by means of sensory interactions between visual, somatosensory and vestibular information and the vestibular–otolithic signals contribute to the accuracy of voluntary arm movements. 相似文献
20.
Objective: The study aimed at examining the usefulness of inter-frequency amplitude ratio (IFAR) of ocular vestibular evoked myogenic potential (oVEMP) in identifying Meniere’s disease (MD) and differentiating it from benign paroxysmal positional vertigo (BPPV). Design: A case-control design was used with a double blind approach. Phase 1 included 70 healthy individuals and 36 individuals each with MD and BPPV and Phase 2 included 20 individuals each with MD and BPPV. The age range of the participants in both phases was 15–50 years. All participants underwent oVEMP testing using 500 and 1000?Hz tone bursts and IFAR was obtained. Results: The results in phase 1 revealed significantly higher IFARs in Meniere’s disease than BPPV and healthy individuals ( p?0.001). An optimum criterion point of IFAR ≥1.11 for diagnosing MD was found which yielded 80% sensitivity and 98% specificity. The results in phase 2 demonstrated 85% correct identification of MD and 95% correct rejection of BPPV as non-MD. Conclusions: IFAR of oVEMP appears highly sensitive and specific parameter for identifying MD and a clinically valid tool for differentiating MD from BPPV. 相似文献
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