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ABSTRACT: This study aimed to determine the optimal bandpass filter (BPF) setting for acoustic stimuli in recording the ocular vestibular-evoked myogenic potential (oVEMP). Twelve healthy volunteers underwent oVEMP tests using acoustic stimuli with various high-pass filters (1, 10 and 100Hz) and low-pass filters (500, 1000 and 2000Hz). Initially, various effects of high-pass filter on the oVEMPs were examined under Conditions A (BPF of 1-1000Hz), B (BPF of 10-1000Hz) and C (BPF of 100-1000Hz). Of these conditions, Condition A showed 100% response rate and had larger nI-pI amplitude than Conditions B and C. Thus, Condition A was selected for subsequent analysis of the various effects of low-pass filter on the oVEMPs. However, Condition A (BPF of 1-1000Hz) did not significantly differ from Conditions D (BPF of 1-500Hz) and E (BPF of 1-2000Hz) in terms of the latencies and amplitudes of oVEMPs. Condition A thus is supposed to be the optimal recording condition for oVEMPs. In conclusion, the optimal BPF setting for acoustic stimuli in recording oVEMPs is suggested to be between 1-1000Hz.
Neuroscience Letters 03/2013; · 2.11 Impact Factor
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ABSTRACT: Background: Vestibular assessment in patients with acoustic tumor (so-called vestibular schwannoma, VS) via ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests are not often discussed in the neurosurgical literature. Objectives: This study conducted physiological and morphological assessments for VS patients before and after CyberKnife radiosurgery. Methods: Twenty patients with unilateral VS underwent a battery of tests comprising facial nerve function test, audiometry, and caloric, oVEMP and cVEMP tests before and 2 years after CyberKnife treatment at a mean dosage of 18 Gy in 3 fractions. Results: The abnormal percentages of caloric, oVEMP and cVEMP tests did not significantly differ before and after Cyberknife treatment, indicating that preservation of the superior and inferior vestibular nerves can be achieved after radiosurgery. Median tumor volumes, 1.49 cm3 before treatment versus 0.97 cm3 at 2 years after treatment, differed significantly. Conclusions: The use of oVEMP and cVEMP tests in VS patients before stereotactic radiosurgery may help to evaluate the tumor origin from the superior or inferior vestibular nerve. It takes a short time and costs less, and it would be practical to make this a routine examination in VS patients having stereotactic radiosurgery.
Stereotactic and Functional Neurosurgery 02/2013; 91(3):177-185. · 1.85 Impact Factor
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ABSTRACT: Objectives: This study investigated the feasibility of the cervical vestibular-evoked myogenic potential (cVEMP) test using bone-conducted vibration (BCV) tapping. Design: Prospective study. Study sample: Initially, 20 healthy volunteers aged 23-38 years underwent cVEMP tests in supine position using head elevation method by BCV tapping at the Fz and inion. On another day, the same subjects underwent cVEMP tests in seated position with head rotation method by BCV tapping at the Fz and inion. Another 20 healthy subjects aged 41-60 years undergoing cVEMP tests by BCV tapping at the inion were also included for comparison. Results: Tapping at the inion (100%) had significantly higher response rate of cVEMPs than tapping at Fz (65-70%), regardless of whether the head was elevated or rotated. Except for mean latencies of p13 and n23, the mean p13-n23 amplitude, corrected amplitude, and asymmetry ratio did not differ significantly between the elevation and rotation methods when cVEMPs were elicited by inion tapping; both methods showed excellent test-retest reliability. Conclusions: The BCV at the inion is the optimal method for eliciting BCV cVEMPs. These responses can be recorded using either the seated/head rotation method or supine/head elevation method.
International journal of audiology 01/2013; · 1.34 Impact Factor
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ABSTRACT: This study utilized audiometry, and cervical vestibular-evoked myogenic potential (cVEMP), ocular VEMP (oVEMP) and caloric tests to investigate the sequence of vestibular deficits in patients with noise-induced hearing loss (NIHL). Thirty patients with NIHL underwent an inner ear test battery. Another 30 normal controls with age- and sex-matched were included for comparison. The abnormal percentages of the audiometry, and cVEMP, oVEMP and caloric tests were 100, 70, 57 and 33 % in NIHL patients, which showed significant differences from 13, 13, 7 and 3 % in normal controls, respectively. A significantly decreasing trend among the four tests, with the sequence of damage from the cochlea, followed by the saccule, utricle, and semicircular canals was noted in NIHL patients, but not in normal controls. In conclusion, the decreasing order of abnormal percentages in the function of the cochlea, saccule, utricle and semicircular canals after chronic noise exposure further supports that the pars inferior (cochlea and saccule) is more vulnerable to noise exposure than the pars superior (utricle and semicircular canals).
Archives of Oto-Rhino-Laryngology 11/2012; · 1.29 Impact Factor
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ABSTRACT: Abstract Conclusion: The age-related changes in ocular vestibular-evoked myogenic potentials (oVEMPs) elicited by galvanic vestibular stimulation (GVS) and bone-conducted vibration (BCV) might be attributed to the morphological degeneration of the vestibular system. Objective: This study employed GVS and BCV modes for eliciting oVEMPs in healthy subjects to explore the effect of aging on the vestibulo-ocular reflex (VOR) pathway. Methods: Sixty-nine healthy subjects (aged 22-69 years) were divided into 5 groups of 12-19 subjects by decades of age. All subjects underwent oVEMPs using GVS and BCV modes. The prevalence and parameters of oVEMPs, including nI latency, pI latency, nI-pI interval, and nI-pI amplitude were measured and compared. Results: The prevalences of GVS-oVEMPs had nonsignificant differences among all age groups, whereas that of BCV-oVEMPs in the over-60 group was significantly lower than those in the under-60 groups. In GVS-oVEMPs, the group over 60 years had significantly longer nI, pI latencies, and smaller amplitudes when compared with those under 60 years. In BCV-oVEMPs, the nI and pI latencies in the over-60 group were significantly longer than those of the under-60 groups, while the nI-pI amplitudes of groups over 50 years were significantly smaller than those of groups under 50 years. All oVEMP parameters exhibited significant differences between GVS- and BCV-oVEMPs in each age group.
Acta oto-laryngologica 10/2012; · 0.98 Impact Factor
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ABSTRACT: OBJECTIVES/HYPOTHESIS: This study investigated the development of otolithic-ocular reflex in small children (<3 years old) via the ocular vestibular-evoked myogenic potential (oVEMP) test. STUDY DESIGN: Prospective study. METHODS: Twenty full-term newborns (group A), 15 children aged 1 to 3 years (group B), and 15 children aged 4 to 13 years (group C) were enrolled in this study. All children underwent auditory brainstem response testing or audiometry, and the oVEMP test. RESULTS: All subjects had normal hearing. Typical biphasic oVEMP waveforms were not observed in the 20 newborns, but were present in six (40%) of 15 children aged 1 to 3 years and all (100%) children aged 4 to 13 years, exhibiting a significant difference. In group B, except for the nine children aged 12 to 24 months, the remaining six children, aged 25 to 47 months, had clear oVEMPs, with the mean nI latency and nI-pI amplitude resembling those in children aged 4 to 13 years, indicating that the otolithic-ocular reflex is mature in children aged >2 years. CONCLUSIONS: Despite the well-developed caloric and cervical VEMP responses in early life, oVEMPs are not present in newborns, but are present in children aged >2 years who can walk with a gait resembling an adult. Maturation of the otolithic-ocular reflex is important to balance control, which is necessary in small children for independent gait. Laryngoscope, 2012.
The Laryngoscope 09/2012; · 1.75 Impact Factor
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ABSTRACT: This study applied ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests in Ménière's patients with Tumarkin falls to investigate the etiologic role of the saccule/utricle in the event of Tumarkin falls.
Retrospective study.
University hospital.
Twenty unilateral definite Ménière's patients were divided into 2 age- and sex-matched groups. Ten patients had a history of drop attacks, and 10 had no history of drop attacks.
All patients underwent audiometry and caloric, oVEMP, and cVEMP tests.
No significant differences were observed between the fall and nonfall groups in terms of Ménière staging, and caloric and cVEMP test results. In the fall group, oVEMP test via Fz tapping showed augmented, reduced, and absent responses in 1, 1, and 8 patients, respectively. In 3 of the latter 8 patients, however, oVEMPs could be obtained by lateral mastoid tapping. Thus, 100% of patients in the fall group had abnormal oVEMPs, which significantly differed from 50% oVEMP abnormalities in the nonfall group. Comparison of the abnormal results for the caloric, oVEMP, and cVEMP tests revealed that poorer residual vestibular function in the fall group than the nonfall group.
Absence of oVEMP by Fz tapping and presence of oVEMPs via lateral tapping indicates a residual utricular function. With residual canal function (canal paresis) and absent cVEMPs, subsequently residual utricular function may trigger the Tumarkin falls in Ménière's patients.
Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 08/2012; 33(7):1251-6. · 1.44 Impact Factor
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ABSTRACT: OBJECTIVE: As otolithic control of blood pressure has been the focus of recent interest, this study investigated the ocular and cervical vestibular-evoked myogenic potential (oVEMP and cVEMP) tests in patients with orthostatic dizziness. METHODS: Sixty patients with orthostatic dizziness and 20 normal controls were consecutively enrolled. All subjects received a battery of tests including audiometry, and caloric, oVEMP and cVEMP tests. RESULTS: Audiometry revealed normal hearing in all 60 patients. Caloric test identified hyperactive and normal responses in 35 and 65 % of patients, respectively. The oVEMP test showed normal responses in 36 patients, and abnormal (absent and reduced) responses in 24 patients (40 %). Most patients (22/24) with abnormal oVEMPs revealed asymmetrical responses. For the cVEMP test, 30 patients (50 %) had normal responses, and 23 and 7 patients showed delayed and absent cVEMPs, respectively. Significant differences existed in the abnormal percentage of oVEMP and cVEMP tests between the patient and control groups. When the oVEMP and cVEMP test results were combined, the abnormal rate increased to 70 % of the patients, resulting in stronger association as an elevated odds ratio of 13.2, greater than 12.7 and 5.7 in the corresponding individual oVEMP and cVEMP tests. INTERPRETATION: Patients with orthostatic dizziness may show asymmetric oVEMPs and abnormal (delayed) cVEMPs. If both test results were combined together, a high abnormality (70 %) was obtained, indicating that in addition to conventional autonomic test battery, the two VEMP tests may serve as a supplementary tool for evaluating orthostatic dizziness.
Clinical Autonomic Research 07/2012; · 1.30 Impact Factor
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ABSTRACT: Objective Patients with delayed endolymphatic hydrops (DEH) underwent a vestibular test battery to evaluate the residual function, assess their clinical stage, and predict outcome. Study Design Case series with chart review. Setting University hospital. Subjects and Methods Twenty patients with DEH, 15 with ipsilateral type and 5 with contralateral type, were enrolled. All patients underwent audiometry and caloric, ocular vestibular-evoked myogenic potential (oVEMP), and cervical VEMP (cVEMP) tests. The DEH staging was based on vestibular test results. Stage 0 indicates that all 3 vestibular tests are normal, while stages I through III indicate abnormal results in tests 1 through 3, respectively. Results Of the 20 DEH patients, 2 patients were stage 0, 12 patients were stage I, 4 patients were stage II, and 2 patients were stage III. The median frequency of vertigo in patients with stages II and III was 4 episodes monthly, significantly less than 15 episodes monthly in those with stages 0 and I. Ipsilateral and contralateral types did not differ significantly in the stage distribution. The percentages of abnormal cVEMP, oVEMP, and caloric test results for patients with ipsilateral type were 80%, 33%, and 13%, not significantly different from those for contralateral type. Conclusions As a vertiginous attack may subside spontaneously for patients with long-term DEH, one must identify its clinical stage based on cVEMP, oVEMP, and caloric test results. In early stage DEH, most vestibular function remained relatively intact, leading to repeated vertiginous attacks. Conversely, subsidence of vertiginous episode can be anticipated in patients with late stage DEH.
Otolaryngology Head and Neck Surgery 06/2012; 147(5):912-8. · 1.72 Impact Factor
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ABSTRACT: This study applied bone vibration (BV) stimulation to the Fz and Fpz sites to investigate the influence of head acceleration on the ocular vestibular-evoked myogenic potentials (oVEMPs).
Prospective study.
Fourteen healthy subjects underwent oVEMP tests combined with real-time triaxial accelerometry.
Under BV stimulation from a vibrator to the Fz and Fpz sites, acceleration magnitudes along x-, y- or z-axis did not significantly differ between the two sites. The mean nI and pI latencies of the oVEMPs stimulated at Fz were significantly earlier than those at Fpz. However, no statistical differences existed in the nI-pI interval and amplitude between the two sites. A blunt or double peak nI configuration was noted in three subjects (22%) when tapping at Fpz, but not at Fz, likely because different muscles contributing to the oVEMPs.
While both Fz and Fpz are effective sites for generating an oVEMP, the variation in human skull shapes and properties will lead to different acceleration profiles being transmitted to the vestibular apparatus. These differing stimuli may lead to different oVEMP profiles, so if one site does not produce the expected response, the clinician should try the other site.
International journal of audiology 04/2012; 51(7):551-6. · 1.34 Impact Factor
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ABSTRACT: This study combined bone-conducted vibration (BCV) stimulation with triaxial accelerometry to correlate the acceleration magnitudes of BCV stimuli with ocular vestibular-evoked myogenic potential (oVEMP) test results. Fourteen healthy volunteers underwent oVEMP test using BCV stimuli with simultaneous monitoring the triaxial acceleration. All (100%) subjects exhibited clear oVEMPs in response to BCV stimuli from a vibrator. The lowest acceleration magnitudes for eliciting oVEMPs along the x-, y- and z-axes were 0.05±0.01 g, 0.16±0.08 g, and 0.04±0.01 g, respectively, exhibiting significantly higher acceleration magnitude along the y-axis than those along the x- and z-axes. In addition, significantly positive correlations were noted between the acceleration magnitude along each axis and the oVEMP amplitude. In conclusion, measuring the acceleration magnitude throughout oVEMP testing revealed a significant correlation between linear acceleration and oVEMP responses. Restated, increasing acceleration magnitude may have more synchronization of firing of vestibular afferents, resulting in more synchronized evoked potentials and greater oVEMP amplitude.
Neuroscience Letters 03/2012; 516(1):75-8. · 2.11 Impact Factor
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ABSTRACT: This study utilized bone-conducted vibration (BCV) stimuli for eliciting ocular vestibular-evoked myogenic potentials (oVEMPs) to assess the vestibulo-ocular reflex (VOR) system in healthy children and adults.
Fifteen healthy children aged 3-14 years and 18 healthy adults aged 24-28 years underwent oVEMP testing. Structural factors such as body weight, body height and body mass index were measured for each healthy subject.
All healthy children and adults presented clear oVEMPs, bilaterally. The characteristic parameters (latencies and amplitude) of oVEMPs did not significantly differ between children and adults. The mean interaural (y-axis) acceleration magnitudes for eliciting oVEMPs were 0.37 ± 0.12 g for children and 0.41 ± 0.20 g for adults, a non-significant difference. As stimulation intensity increased stepwise, interaural acceleration magnitude increased correspondingly, leading to early nI latency and large nI-pI amplitude of oVEMPs. However, no structural factor was statistically correlated with interaural acceleration magnitude.
When children aged >3 years, the simple and quick oVEMP test via BCV stimulation can be used for investigating the integrity of the VOR system, with the characteristic parameters (latencies and amplitude) unaffected by structural factors.
Establishing the norm of oVEMP is essential for diagnosing VOR deficit in children aged >3 years.
Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 02/2012; 123(9):1880-5. · 3.12 Impact Factor
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ABSTRACT: The asymmetry ratio of ocular vestibular-evoked myogenic potential (oVEMP) >40% is interpreted as augmented or reduced response depending on whether the nI-pI amplitude of the lesion ear is larger or smaller than that of the opposite ear, respectively. This study compared unilateral Ménière disease patients with augmented oVEMPs vs reduced oVEMPs to elucidate the mechanism of augmented oVEMP.
Case series with chart review.
University hospital.
Forty patients with unilateral definite Ménière disease were enrolled in this study, including 20 patients with augmented oVEMPs and another 20 patients with reduced oVEMPs in the hydropic side. All patients underwent audiometry, caloric test, and oVEMP and cervical VEMP (cVEMP) tests via bone-conducted vibration stimuli. Then, the oVEMP and cVEMP test results were compared with the stage of Ménière disease, respectively.
The augmented group had earlier nI and pI latencies and larger nI-pI amplitude of oVEMPs compared with the reduced group. Caloric test also revealed a significant difference in abnormal responses between the augmented and reduced groups. However, both groups did not differ significantly in the abnormal percentage of cVEMP test results. A significant trend to decline in the prevalence of augmented oVEMPs was noted from stages I to III-IV but not in that of abnormal cVEMPs.
The augmented oVEMPs have earlier latencies and larger amplitudes compared with the reduced oVEMPs, indicating that a relatively larger population of intact utricular afferents is activated during the early stage of Ménière disease.
Otolaryngology Head and Neck Surgery 01/2012; 146(5):797-803. · 1.72 Impact Factor
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ABSTRACT: Patients with recurrent sudden deafness demonstrating normal vestibular-evoked myogenic potentials (VEMPs) in the lesion ear of the second episode may indicate a good hearing outcome.
This study retrospectively reviewed our experience of patients with recurrent sudden deafness during the past 20 years.
Sixteen (1.4 %) of 1156 patients with sudden deafness were diagnosed as having a recurrent episode, including ipsilateral type in 7 and contralateral type in 9. All patients underwent an audiovestibular test battery and blood and MRI examinations. After 2000, nine patients underwent the VEMP test.
In the ipsilateral type, the mean interval between two episodes was 2 ± 2 years, which did not differ significantly from 3 ± 3 years in the contralateral type. There were no significant differences in relation to age at onset of the second episode, inter-episode interval, gender, presence of vertigo, and abnormal caloric results. However, abnormal rate of VEMP test in the contralateral type (five of five patients) was significantly higher than that in the ipsilateral type (none of four patients). At the second episode, all four patients with normal VEMPs on the lesion ear had improved hearing, while four of five patients with absent or delayed VEMPs showed unchanged hearing. Altogether, the hearing improvement rate in both types of recurrent sudden deafness was 50%.
Acta oto-laryngologica 01/2012; 132(3):247-54. · 0.98 Impact Factor
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ABSTRACT: The ocular vestibular evoked myogenic potential (o-VEMP) test results correlate significantly with caloric test results for patients with acoustic neuroma (AN), but not for patients with Meniere's disease (MD), indicating that the o-VEMP test may replace the caloric test for evaluating the vestibular nerve from which the AN arises. Conversely, the caloric, o-VEMP, and cervical VEMP (c-VEMP) tests should be performed to map lesion sites in the vestibular labyrinth.
This study performed caloric, o-VEMP, and c-VEMP tests on patients with central and peripheral vestibular disorders to investigate their relationships.
In all, 66 patients comprising 16 with unilateral AN and 50 with unilateral definite MD were enrolled. All patients underwent caloric, o-VEMP, and c-VEMP tests.
In the AN group, the caloric test identified canal paresis and caloric areflexia in 10 ears, while the o-VEMP and c-VEMP tests identified abnormal (absent or delayed) responses in 12 and 11 ears, respectively. A significant correlation existed between caloric and o-VEMP test results, but not between caloric and c-VEMP test results, or between o-VEMP and c-VEMP test results. For the MD group, abnormal caloric, o-VEMP, and c-VEMP test results were obtained for 24%, 44%, and 38% of hydropic ears, respectively. No correlation existed between any two test results.
Acta oto-laryngologica 11/2011; 132(2):160-6. · 0.98 Impact Factor
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ABSTRACT: Objective. This study compared bone-conducted vibration (BCV) stimuli at forehead (Fz) and mastoid sites for eliciting ocular vestibular-evoked myogenic potentials (oVEMPs).Study Design. Prospective study.Setting. University hospital.Methods. Twenty healthy subjects underwent oVEMP testing via BCV stimuli at Fz and mastoid sites. Another 50 patients with unilateral Meniere's disease also underwent oVEMP testing.Results. All healthy subjects showed clear oVEMPs via BCV stimulation regardless of the tapping sites. The right oVEMPs stimulated by tapping at the right mastoid had earlier nI and pI latencies and a larger nI-pI amplitude compared with those stimulated by tapping at the Fz and left mastoid. Similar trends were also observed in left oVEMPs. However, the asymmetry ratio did not differ significantly between the ipsilateral mastoid and Fz sites. Clinically, tapping at the Fz revealed absent oVEMPs in 28% of Meniere's ears, which decreased to 16% when tapping at the ipsilesional (hydropic) mastoid site, exhibiting a significant difference.Conclusion. Tapping at the ipsilateral mastoid site elicits earlier oVEMP latencies and larger oVEMP amplitudes when compared with tapping at the Fz site. Thus, tapping at the Fz site is suggested to screen for the otolithic function, whereas tapping at the ipsilesional mastoid site is suitable for evaluating residual otolithic function.
Otolaryngology Head and Neck Surgery 10/2011; · 1.72 Impact Factor
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ABSTRACT: The fourth ventricle encompasses many vital structures including the brainstem as its floor and the cerebellum as its lateral wall and roof. Therefore, lesions affecting the fourth ventricle may present as cerebellar or brainstem manifestations. Herein, we presented our experience in the diagnosis of disorders affecting the fourth ventricle during the past 15 years.
Retrospective study.
University hospital.
From September 1995 to August 2010, 24,838 patients with vertigo/dizziness visited the clinic. Of them, 13 patients (0.5%) had tumor/stroke affecting the fourth ventricle.
All patients underwent a battery of audiovestibular function test.
All patients had vertigo (100%) and then ataxia (92%) and nausea/vomiting (85%). Eight patients (68%) displayed persistent nystagmus. Most (>75%) patients showed central signs in electronystagmographic recordings and abnormal caloric coupled with visual suppression test. Three patients underwent both ocular and cervical vestibular-evoked myogenic potential tests, and abnormal results were noted in all 3 patients indicating a brainstem involvement. However, magnetic resonance imaging failed to demonstrate brainstem lesion in these 3 patients. Final diagnoses consisted of the following: cavernoma, n = 3; metastatic cancer, n = 3; astrocytoma, n = 2; meningioma, n = 2; epidermoid cyst, n = 1; ependymoma, n = 1; and lymphoma, n = 1. The prognosis was poor as 10 patients (77%) died within 2 years.
When a vertiginous patient displayed ataxia, persistent vomiting, and persistent nystagmus, lesion affecting the fourth ventricle should be kept in mind because its prognosis is poor. Abnormal results in electronystagmography and in ocular and cervical vestibular-evoked myogenic potentials may serve as a supplementary to magnetic resonance imaging to delineate the involvement of the lesion.
Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 09/2011; 32(8):1329-35. · 1.44 Impact Factor
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Clinical neurology and neurosurgery 07/2011; 114(1):50-3. · 1.30 Impact Factor
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ABSTRACT: This study compared the characteristic parameters of ocular vestibular-evoked myogenic potential (oVEMP) test between eyes gazing up and eyes closed to evaluate the feasibility of oVEMP test with eyes closed.
Twenty-three healthy adults underwent oVEMP testing with upward gaze and with eyes closed in a randomized order. For each condition, the thickness of the inferior oblique and inferior rectus muscles, and the distance from the electrode on the skin to each muscle were measured via ultrasonography. Two patients with pathological ears were also included in this study for comparison.
Twenty of the 23 subjects showed clear oVEMPs regardless of whether eyes were gazing up or eyes were closed. Mean latencies of nI and pI, and nI-pI interval with eyes closed were significantly prolonged when compared with those measured with eyes up. The mean nI-pI amplitude with eyes closed was significantly smaller than that with eyes up. However, no significant difference existed in the mean asymmetry ratio of amplitude between the two conditions. With eyes closed, the mean distances from the skin to the inferior oblique and inferior rectus muscles are 0.17±0.03 and 0.40±0.09 cm, respectively. In contrast with eyes gazing up, the mean distance from the skin to the inferior rectus muscle reduces significantly to 0.23±0.09 cm, whereas the inferior oblique muscle slips out of ultrasonographic view.
Ocular VEMP can also be recorded with eyes closed in those who cannot perform upward gaze. However, the characteristic parameters of oVEMP are different between the eyes up and eyes closed conditions, probably because various extraocular muscles are involved in the generation of oVEMPs.
In those who cannot gaze upward such as small children, oVEMPs can be recorded by eyes closed.
Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 07/2011; 123(2):376-81. · 3.12 Impact Factor
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ABSTRACT: This study applied both ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests in patients with cerebellar disorders to determine whether VEMP test can differentiate between cerebellar and brainstem lesions. A total of 12 patients with cerebellar disorder, including extended cerebellar lesion (involving the brainstem) in 8 and localized cerebellar lesion (excluding the brainstem) in 4, were enrolled in this study. All patients underwent caloric, visual suppression, and oVEMP and cVEMP tests via bone-conducted vibration stimuli. The abnormal rates for the caloric, visual suppression, and oVEMP and cVEMP tests were 62, 83, 88 and 75% in patients with extended cerebellar lesion and 0, 25, 0 and 0% in those with localized cerebellar lesion, respectively. The rate of abnormal oVEMP results significantly differed between the two groups, but caloric, visual suppression and cVEMP test results did not differ. In another ten healthy subjects, characteristic parameters of oVEMPs obtained under light and dark conditions did not significantly differ. In conclusion, ocular VEMP test can differentiate between cerebellar and brainstem lesions. Abnormal oVEMPs in patients with cerebellar disorder may indicate adjacent brainstem involvement.
Archives of Oto-Rhino-Laryngology 06/2011; 268(6):923-30. · 1.29 Impact Factor
