Patient and normal three-dimensional eye-movement responses to maintained (DC) surface galvanic vestibular stimulation.

HYPOTHESIS: That disease or dysfunction of vestibular end organs in human patients will reduce or eliminate the contribution of the affected end organs to the total eye-movement response to DC surface galvanic vestibular stimulation (GVS). BACKGROUND: It was assumed that DC GVS (at current of 5 mA) stimulates all vestibular end organs, an assumption that is strongly supported by physiological evidence, including the activation of primary vestibular afferent neurons by galvanic stimulation. Previous studies also have described the oculomotor responses to vestibular activation. Stimulation of individual semicircular canals results in eye movements parallel to the plane of the stimulated canal, and stimulation of the utricular macula produces changes in ocular torsional position. It was also assumed that the total three-dimensional eye-movement response to GVS is the sum of the contributions of the oculomotor drive of all the vestibular end organs. If a particular vestibular end organ were to be diseased or dysfunctional, it was reasoned that its contribution to the GVS-induced oculomotor response would be reduced or absent and that patients thus affected would have a systematic difference in their GVS-induced oculomotor response compared with the response of normal healthy individuals. METHODS: Three-dimensional video eye-movement recording was carried out in complete darkness on normal healthy subjects and patients with various types of vestibular dysfunction, as diagnosed by independent vestibular clinical tests. The eye-movement response to long-duration bilateral and unilateral surface GVS was measured. RESULTS: The pattern of horizontal, vertical, and torsional eye velocity and eye position during GVS of patients independently diagnosed with bilateral vestibular dysfunction, unilateral vestibular dysfunction, CHARGE syndrome (semicircular canal hypoplasia), semicircular canal occlusion, or inferior vestibular neuritis differed systematically from the responses of normal healthy subjects in ways that corresponded to the expectations from the conceptual approach of the study. CONCLUSION: The study reports the first data on the differences between the normal response to GVS and those of patients with a number of clinical vestibular conditions including unilateral vestibular loss, canal block, and vestibular neuritis. The GVS-induced eye-movement patterns of patients with vestibular dysfunction are consistent with the reduction or absence of oculomotor contribution from the end organs implicated in their particular disease condition.     

Mechanisms of vibration-induced nystagmus in normal subjects and patients with vestibular neuritis

It has been reported that vibration applied either on the mastoid or on the sternocleidomastoid (SCM) muscles induces nystagmus in normal subjects or patients after unilateral vestibular neuritis (VN). The aims of the study were to characterize vibration-induced nystagmus (VIN) in normal and patient groups and to propose the mechanism of VIN. We recorded eye movements during unilateral 100-Hz vibration on the mastoid bone and SCM muscles in 22 normal subjects and 19 patients with unilateral VN. In normal subjects, the direction of slow-phase velocity (SPV) tended to be toward the vibrated side. Vibration on the right/left SCM muscles induced mean SPV of 1.7 degrees/s, -1.9 degrees/s toward the stimulated side in all normal subjects. Vibration on the right/left mastoid bone induced mean SPV of 1.5 degrees/s, -0.4 degrees/s toward the stimulated side in most of the normal subjects. Positive value means SPV to the right side. This directional preponderance to the vibrated side was statistically significant. Among the patients with VN, the slow phase of the VIN was directed towards the lesioned side, irrespective of whether vibration was applied on the lesioned or intact side. Vibration on the right/left mastoid bone induced mean SPV of -10.4 degrees/s, -10.8 degrees/s toward the lesioned side. Vibration on the right/left SCM induced mean SPV of -7.9 degrees/s, -10.5 degrees/s toward the lesioned side. The amplitude of SPV showed a significant correlation with the unilateral weakness of caloric test. Our results suggest that the proprioceptive stimulation plays a major role in producing VIN in normal subjects, while VIN is generated mostly by the vestibular stimulation in patients with unilateral VN, which helps us localize the lesion side. Vibration tests on the SCM muscles as well as on the mastoid are recommended and our hypothetic mechanisms of VIN are presented.     

Head-shaking nystagmus in patients with unilateral peripheral vestibular lesions

In certain patients with peripheral or central vestibular lesions, a transient nystagmus appears after shaking the head rapidly for 10 to 20 cycles. We recorded such a "head-shaking nystagmus" using the scleral eye coil in six subjects with unilateral peripheral vestibular lesions. Horizontal head shaking elicited horizontal nystagmus with slow phases that were initially directed toward the side of the lesion and upward. All subjects showed a prolonged, lower-amplitude reversal phase after the initial response following horizontal head shaking. The main features of these results can be explained by an analytic model that incorporates a central velocity-storage mechanism that perseverates vestibular inputs, Ewald's second law, and adaptation of primary vestibular afferent activity.     

单侧前庭功能丧失患者前庭眼反射和视支反射眼震电图定量 …

OBJECTIVE: To study changes of the vestibular function in the process of vestibular compensation. METHODS: The electronystagmography recording of spontaneous nystagmus(SN) with tests for vestibulo-ocular reflex (VOR) and optokinetic reflex (OKR) were performed in 105 patients with unilateral loss of vestibular function, the results were analysed quantitatively. RESULTS: (1) Twenty-one patients with courses from 3 days to 6 years presented a SN directed towards the intact side, with an average slow phase velocity (ASPV) of 7.12-12.07 degrees/s. (2) The intensity of VOR nystagmus as a response to the warm-cold water stimulation to the intact ear was lower than that of normal subjects. (3) By 0.167 Hz, 90 degrees sinusional oscillation stimulation, the ASPVs of the patients' VOR nystagmus directed towards the intact and affected sides were lower than that of the normal. A predominance of VOR nystagmus rotation towards the intact side was found in patients with courses < or = 5 years. There was no predominance of VOR nystagmus found in patients with courses > 5 years. (4) There was no significant difference between the optokinetic nystagmus (OKN) intensity of the normal persons and that of patients with lesions outside the cerebellopontine angle and with tumors in cerebellopontine angle which was < 2.5 cm in diameter. The OKN intensity of patients with tumors in cerebellopotine angle with diameters > or = 2.5 cm was lower than that of normal subjects. A predominance of OKN towards the intactside was found in these patients. CONCLUSION: The vestibular function is in inhibitory and the vestibular system becomes rebalanced due to this inhibition in the process of vestibular compensation.     

Diagnostic value of eye movement and vestibular function tests in patients with posterior circulation infarction

Objective: To evaluate the diagnostic value of eye movements and vestibular function tests in PCI patients.

Methods: Thirty-eight PCI patients and 31 patients with unilateral vestibular neuritis (UVN) were enrolled and underwent eye movement tests and vestibular function tests (spontaneous nystagmus [SN], head-shaking nystagmus [HSN]).

Results: The rates of eye movement abnormality were 78.9% and 41.9% in PCI and UVN patients, respectively. The positive rate of SN and HSN were, respectively, 41.2% and 43.8% in cerebellar infarction patients, 33.3% and 66.7% in medullary infarction patients, and 100.0% and 86.2% in UVN patients. The horizontal direction of SN and HSN coincided with the affected side in cerebellar infarction patients, and the healthy side in UVN patients, which coincided with the healthy side and the affected side, respectively in medullary infarction patients. The horizontal direction of HSN was bidirectional nystagmus in 16.0% (4/25) of UVN patients.

Conclusions and significance: Eye movement and vestibular function tests contribute to the early diagnosis of PCI. The horizontal direction of SN and HSN are consistently toward the affected side in cerebellar infarction patients and the healthy side in UVN patients, in contrast to medullary infarction patients, and deserve further investigations.     

Head-shaking nystagmus: a sensitive indicator of vestibular dysfunction

This study investigated 258 consecutive patients with the complaint of vertigo undergoing vestibular function tests between August 1992 and July 1994. The head-shaking nystagmus test was performed in a passive fashion with the patient placed in a sitting position with the head anteflexed at 30° and oscillated ±45° horizontally for 30 cycles in 15 s; the post head-shaking nystagmus was recorded by electronystagmography. Conventional bithermal caloric tests were conducted with the normal limit of canal paresis set at 20%. The results show significant correlation between head-shaking nystagmus and canal paresis. Head-shaking nystagmus is more sensitive than canal paresis in predicting vestibular dysfunction. The sensitivity of head-shaking nystagmus in detecting a canal paresis was 90%. Although the direction of head-shaking nystagmus does not always accord with the side of peripheral vestibular dysfunction, it is an indicator of vestibular dysfunction and this test could be performed easily as a screening test in every otoneurological investigation.     

震动眼震在单侧前庭外周疾病中的临床意义

目的研究震动眼震（vibration—induced nystagmu，VIN）在前庭外周疾病诊断中的临床意义，并确定震动实验（vibration test，VT）的灵敏度和特异度。方法30例健康成人和眩晕门诊112例单侧外周前庭疾病患者纳入本研究，排除具有自发性眼震患者，采用置于乳突和前额的震动刺激（92Hz）进行震动实验，观察记录VIN的诱发情况，患者和正常受试者同时还进行摇头眼震（headshaking nystagmus，HSN）和前庭双温冷热试验检查，并进行比较。结果112例患者中，有91例（81％）出现VIN，主要是水平眼震，VIN在乳突比在前额更常诱发出，其中76例VIN的方向朝向健侧，然而15例梅尼埃病患者VIN方向朝向患侧。30例健康受试者，均未出现VIN。随着前庭双温冷热试验中半规管轻瘫（canal paresis，CP）值的增加，VIN出现率增加。分别有70例（63％）单侧外周前庭疾病患者和9例健康受试者（30％）出现HSN。前庭双温检查，112例患者中CP值〈25％有10例，25％≤CP值≤40％有32例，40％〈CP值〈70％有48例，cP值≥70％有22例，30例健康受试者CP值均〈25％，VIN出现率随着cP值的增加而增加。结论VIN检查是一项简单、非侵入性的、患者能很好耐受的检测单侧外周前庭功能障碍的临床测试方法，具有比HSN检查更高的灵敏度和特异度。     

Vibration-induced nystagmus - A sign of unilateral vestibular deficit

Vibrations of 60 Hz and 100 Hz were applied on the mastoid of healthy subjects, patients with unilateral peripheral vestibular lesions, with central lesions of different localizations, and patients with benign paroxysmal positioning vertigo (BPPV). In patients with unilateral peripheral deficit a horizontal nystagmus with a small torsional component beating generally to the not affected side could be observed. This nystagmus did not show adaptation during 40 s. The occurrence was more frequent using 60-Hz stimulations. This vibration-induced nystagmus did never occur in healthy subjects, seldom in patients with central vertigo, and only exceptionally in patients with BPPV. It is concluded that the finding of a vibration-induced nystagmus reflects a side difference of peripheral vestibular excitability.     

Head‐shaking nystagmus in patients with a vestibular schwannoma

Head‐shaking nystagmus in patients with a vestibular schwannoma The aim of this study was to calculate the sensitivity of the head‐shake test for peripheral and central vestibular dysfunction associated with unilateral sporadic vestibular schwannoma and to discuss the feasibility of using the head‐shake test as a screening test. The study group consisted of 102 patients with unilateral sporadic vestibular schwannomas, who were seen consecutively for preoperative vestibular assessment, including the head‐shake test. The sensitivity of the head‐shake test for vestibular schwannoma was found to be 22%, and the sensitivity and specificity of the head‐shake test for canal paresis (≥25%) were found to be 27% and 88%, respectively. Patients with abnormalities in the central vestibular system and with a greater canal paresis were more likely to have head‐shake nystagmus, although, even for severe canal paresis, the sensitivity of the test remained low at 36%. The direction of nystagmus was found to be contra‐lateral to the side of the tumour in 86% of patients. It was concluded that the head‐shake test is of insufficient sensitivity to be used as a screening test either for vestibular schwannoma or for vestibular‐system abnormalities associated with vestibular schwannoma. The deduction is made that the head‐shake test is of insufficient sensitivity or specificity to be of clinical value as a screening test for vestibular dysfunction in a general population with symptoms of imbalance.     

The influence of dorsal neck proprioceptive inputs on vestibular compensation--by three-dimensional analysis of neck-induced nystagmus

The influence of dorsal neck proprioceptive inputs on vestibular compensation was investigated in 21 patients with unilateral vestibular dysfunction. Subjects neither had history of spontaneous nystagmus nor of disequilibrium, indicating that they were in a good compensated stage. However, marked nystagmus was induced by applying vibratory stimulation to the dorsal neck of the patients, using a vibrator with a frequency of 110 Hz. The nystagmus was three-dimensional as analyzed by applying computerized eye movement analysis system. Twelve of 21 patients (57%) demonstrated three components of eye movement. All subjects showed a horizontal component directed towards the contralateral side of the vestibular lesion. Vertical and torsional components of the nystagmus were exhibited by 18 and 14 subjects, respectively. The average percentages of slow phase velocity of the horizontal, vertical and torsional components were 57%, 23% and 20%, respectively. No tendency towards any of the three components was observed. Furthermore, in order to investigate the relation between dorsal neck proprioceptive inputs and vestibular outputs, especially semicircular canal outputs, the author compared the direction of the nystagmus with the orientation of the semicircular canals. Normalized average velocity vectors of the nystagmus were calculated. In most subjects, the velocity vectors of the nystagmus were related to the horizontal semicircular canal. These results suggest that by controlling the neck proprioceptive inputs, neck vibration can cause discompensation in vestibularly well-compensated subjects with unilateral dysfunction secondary to vestibular lesion, and that neck proprioceptive inputs have a great influence on the horizontal vestibulo-ocular reflex pathways. However, in a few subjects the average vectors of the nystagmus were related to the vertical semicircular canals. This suggests that the proprioceptive inputs may also be related to the vertical vestibulo-ocular reflex pathways.     

Habituation to galvanic vestibular stimulation for analysis of susceptibility to carsickness

Objective In a previous study we developed a standardized procedure for a reproducible quantification of galvanic-induced body sway (GBS). In line with other reports, GBS shows short-term (fast) habituation upon stimulus repetition. The aim of this study was to evaluate whether the degree of short-term habituation to galvanic vestibular stimulation (GVS) is correlated with susceptibility to carsickness.

Material and Methods A total of 24 female subjects underwent computer-controlled GVS as part of a prospective experimental study conducted in a tertiary referral center. A binaural 1–cosinusoidal stimulus of 0.5 Hz and 1 mA was repeated five times. Binaural stimulation was chosen to obtain maximum responses, making possible habituation to repetitive GVS obvious. The groups consisted of 12 subjects suffering from carsickness and 12 healthy subjects.

Results Analysis of the repeated measurements test showed that the GBS–gain curve for the carsickness group was always superimposed on that for the healthy subjects. However, the (absolute) first to fifth GBS gains showed no significant differences (p=0.134?0.995). When comparing short-term habituation in subjects suffering from carsickness versus healthy subjects, the results showed no differences in the mean values of the first (30.534% vs 27.024%), final (42.637% vs 38.544%) and average (35.544% vs 33.644%) habituations (p=0.875, 0.991 and 0.951, respectively).

Conclusion We did not observe any significant differences in sensitivity or habituation of the GBS in carsick subjects compared to healthy subjects. This implies that carsick subjects show a similar ability to discard an irrelevant, non-motion sickness-inducing galvanic stimulus as healthy subjects.     

The effects of stochastic monopolar galvanic vestibular stimulation on human postural sway

Galvanic vestibular stimulation (GVS) is a technique in which small currents are delivered transcutaneously to the afferent nerve endings of the vestibular system through electrodes placed over the mastoid bones. The applied current alters the firing rates of the peripheral vestibular afferents, causing a shift in a standing subject's vestibular perception and a corresponding postural sway. Previously, we showed that in subjects who are facing forward, stochastic bipolar binaural GVS leads to coherent stochastic mediolateral postural sway. The goal of this pilot study was to extend that work and to test the hypothesis that in subjects who are facing forward, stochastic monopolar binaural GVS leads to coherent stochastic anteroposterior postural sway. Stochastic monopolar binaural GVS was applied to ten healthy young subjects. Twenty-four trials, each containing a different galvanic input stimulus from among eight different frequency ranges, were conducted on each subject. Postural sway was evaluated through analysis of the center-of-pressure (COP) displacements under each subject's feet. Spectral analysis was performed on the galvanic stimuli and the COP displacement time series to calculate the coherence spectra. Significant coherence was found between the galvanic input signal and the anteroposterior COP displacement in some of the trials (i.e., at least one) in nine of the ten subjects. In general, the coherence values were highest for the mid-range frequencies that were tested, and lowest for the low- and high-range frequencies. However, the coherence values we obtained were lower than those we previously reported for stochastic bipolar binaural GVS and mediolateral sway. These differences may be due to fundamental characteristics of the vestibular system such as lower sensitivity to symmetric changes in afferent firing dynamics, and/or differences between the biomechanics of anteroposterior and mediolateral sway.     

Changes in vestibular evoked myogenic potentials after Meniere attacks

OBJECTIVES: The aim of this study was to apply videonystagmography (VNG) and vestibular evoked myogenic potential (VEMP) tests to patients with Meniere attacks, to explore the mechanics of where saccular disorders may affect the semicircular canals. METHODS: From January 2001 to December 2003, 12 consecutive patients with unilateral definite Meniere's disease with vertiginous attacks underwent VNG for recording spontaneous nystagmus, as well as VEMP tests. RESULTS: At the very beginning of the Meniere attack, the spontaneous nystagmus beat toward the lesion side in 5 patients (42%) and toward the healthy side in 7 patients (58%). Twenty-four hours later, only 6 patients (50%) showed spontaneous nystagmus beating toward the healthy side. Nevertheless, spontaneous nystagmus subsided in all patients within 48 hours. The VEMP test was performed within 24 hours of a Meniere attack; the VEMPs were normal in 4 patients and abnormal in 8 patients (67%). After 48 hours, 4 patients with initially abnormal VEMPs had resolution and return to normal VEMPs, and the other 4 patients still had absent VEMPs. CONCLUSIONS: Most patients (67%) with Meniere attacks revealed abnormal VEMPs, indicating that the saccule participates in a Meniere attack. This is an important idea that stimulates consideration of the mechanism of Meniere attacks.     

Electronystagmographic analysis of caloric test parameters in vestibular disorders

The electronystagmographical analysis of the eye movements provoked by caloric stimulation is an important method in the evaluation and topical diagnostic procedure of several vestibular lesions. The aim of the study was to compare the electronystagmographical results of caloric response in several vestibular disorders. The patients were divided into five groups: right and left unilateral and bilateral peripheral lesions, central vestibular dysfunction, and normal vestibular function. In the normal vestibular system group the average caloric nystagmus SPV in normal vestibular system was 17.4°/s. In the peripheral lesion groups the average slow phase velocities are decreased in the affected side, as we expected. In the compensated vestibular lesion the average ASPV of caloric nystagmus is also decreased on the unaffected side. This might be caused by the effect of the central adaptive mechanisms. According to our observations, in central dysfunctions the average caloric ASPV and the spontaneous nystagmus ASPV is increased (25.0°/s). This suggests that in central vestibular lesions the central inhibiting mechanisms of the caloric response are impaired. Our results show that electronystagmographical analysis of spontaneous and caloric nystagmus is very important in the evaluation of dizzy patients.     

Nystagmus induced by high frequency vibrations of the skull in total unilateral peripheral vestibular lesions

CONCLUSION: The skull vibration-induced nystagmus test (SVINT) is a useful complementary test to the caloric test, which evaluates very low frequencies, and the head shaking test (HST), which explores medium range frequencies. These three tests are fully correlated in total unilateral vestibular lesions (tUVL) with a sensitivity of 98% and a specificity of 94% for the SVINT. The results of the interference of the SVINT with the cold caloric test on the intact ear suggest that different vestibular sensory cells are involved in these two tests. The stimulus location optimization suggests that vibrations directly stimulate the inner ear on the intact side. OBJECTIVES: The aim of this study was to establish the effectiveness of a rapid, non-invasive test used to detect vestibular asymmetry at 30, 60 and 100 Hz stimulation in tUVL. PATIENTS AND METHODS: The high frequency vibration test applied to the skull using the SVINT was compared to the results of HST and caloric test in 134 patients and 95 normal subjects: 131 patients had a total unilateral vestibular dysfunction and 3 had a bilateral total lesion (tBVL). The effects of stimulus frequency, topography and head position were studied using a video-nystagmograph. RESULTS: In tUVL, the SVINT always revealed a lesional nystagmus beating toward the healthy side at all frequencies. The mastoid site was more efficient than the cervical and vertex sites (p0.005). The mean skull vibratory nystagmus (SVN) slow phase velocity (SPV) is 10.7 degrees (SD =7.5; n=20). Mastoid stimulation efficiency was not correlated with the side of stimulation. SVN SPV was correlated with the total caloric efficiency on the healthy ear (p=0.03). The interference of the SVINT during the cold caloric test on the intact ear demonstrated a reversal of the caloric nystagmus at each application of the vibrator. In tBVL, SVINT revealed no nystagmus.     

Rotatory evoked cortical potentials in normal subjects and patients with unilateral and bilateral vestibular loss

Summary Rotatory evoked late potentials following clockwise and counterclockwise rotational acceleration were measured in subjects with normal labyrinthine function and in patients with unilateral and bilateral vestibular loss. In the normal subjects the threshold of the evoked cortical responses ranged between 4°/s² and 7°/s², independent of the direction of rotation. For patients with unilateral vestibular loss thresholds were found to be dependent on the direction of rotation. The difference in threshold between clockwise and counter-clockwise rotation was at least 5°/s². The threshold for rotational accelerations in the direction of the healthy labyrinth was higher for patients with compensated unilateral losses. Those patients who still exhibited lesion-associated nystagmus manifested a higher threshold in the direction of the defective labyrinth. In those patients with bilateral vestibular loss, thresholds were found to be independent of the direction of rotation and were of the order of 20°/s². The results indicate that the late potentials reflect the interaction of somatosensory and vestibular stimulation. The difference in threshold (approx. 15%°/s²) between the normal subjects and patients with bilateral vestibular loss suggests that the vestibular component predominates at low accelerations, with the somatosensory component assuming significance at higher acceleration levels.     

A study on vestibular-evoked myogenic potentials via galvanic vestibular stimulation in normal people

Objectives

The aim of our study is to examine vestibular-evoked myogenic potentials (VEMPs) elicited by the galvanic vestibular stimulation in the sternocleidomastoid muscle (SCM) in healthy subjects for clinical applications of auditory neuropathy or vestibular neuropathy in the future.

Functional significance of peripheral head-shaking nystagmus

OBJECTIVES/HYPOTHESIS: The objective was to determine the characteristics of horizontal head-shaking nystagmus of peripheral origin and its relationship to vestibular dysfunction. STUDY DESIGN: Retrospective case series. METHODS: Eighty-three patients met the inclusion criteria of having peripheral and unilateral vestibular disease. Patients were tested with video nystagmography. Head-shaking nystagmus was performed in the horizontal plane during 30 cycles at a frequency of approximately 3 Hz. Head-shaking nystagmus was classified as monophasic or biphasic and, based on the pathological ear, as ipsilateral or contralateral related to nystagmus fast phases. The two-tailed t test, ANOVA, Mann-Whitney and chi2 tests, and lineal and polynomial regression tests were used for statistical analysis. RESULTS: Twenty-three patients showed a positive head-shaking nystagmus. All cases of head-shaking nystagmus observed were horizontal. There were four biphasic and 19 monophasic cases of head-shaking nystagmus. First phases of biphasic head-shaking nystagmus beat toward the normal ear. Eleven of the monophasic cases of head-shaking nystagmus were ipsilateral, and nine were contralateral. There was a statistically significant correlation between caloric weakness and head-shaking nystagmus. Ipsilateral head-shaking nystagmus corresponded to lower caloric asymmetries, and contralateral and biphasic head-shaking nystagmus corresponded to greater caloric weakness (P <.001). As the caloric asymmetry increased, the maximal slow-phase eye velocity of head-shaking nystagmus was greater (P =.01) and its duration shortened (P =.008). Ipsilateral responses could be distinguished from contralateral responses based on their latency (P =.03), maximal slow-phase eye velocity (P <.05), and duration (P =.02). The frequency of head-shaking nystagmus was significantly higher among older patients. There was no correlation between head-shaking nystagmus and clinical patterns. CONCLUSION: Head-shaking nystagmus of peripheral vestibular origin is a response both qualitatively and quantitatively associated with the degree of the vestibular loss.     

原发性良性阵发性位置性眩晕患者前庭诱发肌源性电位检测的意义

目的：探讨检测眼肌前庭诱发肌源性电位（oVEMP）和颈肌前庭诱发肌源性电位（cVEMP）对单侧原发性良性阵发性位置性眩晕（BPPV）患者进行可能发病部位的定位诊断价值。方法：对52例单侧原发性BP-PV患者（BPPV组）和38例正常人（对照组）分别进行气导短纯音诱发的oVEMP和cVEMP检测,分析两种反射的引出率、潜伏期、振幅等数据。结果;BPPV组患侧oVEMP的引出率为46．15％,cVEMP的引出率为67．31％;其健侧oVEMP的引出率为48．08％,cVEMP的引出率为65．38％。对照组左侧oVEMP的引出率84．21％,cVEMP的引出率92．11％;右侧oVEMP的引出率为81．58％,cVEMP的引出率为94．74％。对照组双侧cVEMP和oVEMP的P1、N1潜伏期及N1-P1振幅值差异均无统计学意义。BPPV组和对照组cVEMP和oVEMP耳间振幅比及不对称率差异有统计学意义（P〈0．05）。结论：单侧原发性BPPV患者双侧前庭耳石器传导通路功能受损状况,可以通过oVEMP和cVEMP检测进行客观评估,并且oVEMP的异常率比cVEMP高。     

全聋型突发性耳聋患者的预后与前庭症状及前庭功能关系的回顾性分析

目的 探讨全聋型突发性耳聋患者的预后与前庭症状及前庭功能的关系。 方法 回顾性分析52例单侧全聋型突发性耳聋患者的前庭症状,以及眼肌前庭诱发肌源性电位(oVEMP)、颈肌前庭诱发肌源性电位(cVEMP)、视频头脉冲试验(vHIT)和冷热试验结果,观察这些患者的听力结果与前庭症状及前庭功能的关系。 结果 在52例单侧全聋型突发性耳聋患者中,有前庭症状、前庭功能异常的全聋型患者与无前庭症状者、功能正常者相比疗效差异有统计学意义。oVEMP、cVEMP、vHIT和冷热试验四项结果异常的全聋型患者显示出更低的治疗总有效率,oVEMP、cVEMP、vHIT和冷热试验正常的突发性耳聋患者有更高的听力恢复数值。 结论 有前庭症状、前庭功能异常的全聋型突发性耳聋患者疗效较差,oVEMP、cVEMP、vHIT和冷热试验正常的全聋型突发性耳聋患者有更好的听力恢复。前庭功能异常提示突发性聋患者的内耳病变范围较大、程度较重。