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The ocular vestibular evoked myogenic potential (oVEMP) is a relatively new method used to assess otolith-ocular pathways in humans. When elicited using air-conducted (AC) sound stimulation, the oVEMP is thought to reflect mostly ...
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The ocular vestibular evoked myogenic potential (oVEMP) is a relatively new method used to assess otolith-ocular pathways in humans. When elicited using air-conducted (AC) sound stimulation, the oVEMP is thought to reflect mostly saccular activation. However, it has been recently suggested that utricular afferents may also contribute to the AC evoked oVEMP. While previous frequency tuning studies of the AC evoked oVEMP report predominately high frequency sensitivity (>400 Hz), few have included the lower frequencies (<200 Hz) at which it has been proposed the utricle is most sensitive. In this study, ten normal subjects were stimulated with AC sound delivered unilaterally using headphones over frequencies from 50 to 1,200 Hz at a near constant A-weighted intensity of 120 dB peak sound pressure level. For AC stimulation, the oVEMP demonstrated maximum amplitudes around 600 Hz, with a second, smaller peak occurring around 100 Hz. The AC evoked oVEMP tuning has two peaks, a dominant one consistent with excitation of the saccule and a smaller one consistent with excitation of the utricle.
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Purpose Ageing is process that brings about steady decline in most of the systems, and vestibular system is no different. Although the effects of advancing age on the functioning of the semicircular canals and saccule has been wel...
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Purpose Ageing is process that brings about steady decline in most of the systems, and vestibular system is no different. Although the effects of advancing age on the functioning of the semicircular canals and saccule has been well explored, its impact on the utricle remains the least studied component. While some researchers have investigated the effect of advancing age on the utricular functioning by virtue of studying ocular-vestibular evoked myogenic potentials (oVEMP), the use of smaller sample sizes would hamper the generalization of their results. Therefore, the present study aimed at investigating the effect of advancing age on oVEMP using a substantially larger sample size than the predecessors.
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Objective: To define and compare the input-output properties of 500 Hz and 100 Hz bone-conducted (BC) transmastoid stimulation when evoking cVEMPs and oVEMPs. The findings for 500 Hz were compared with those previously reported fo...
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Objective: To define and compare the input-output properties of 500 Hz and 100 Hz bone-conducted (BC) transmastoid stimulation when evoking cVEMPs and oVEMPs. The findings for 500 Hz were compared with those previously reported for air-conducted (AC) 500 Hz stimulation.
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Background: It has been shown that vestibule structural alterations may have an impact on the physiological alterations that take place during menstruation. As the cycle progresses, the hormone levels change at various times. As a...
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Background: It has been shown that vestibule structural alterations may have an impact on the physiological alterations that take place during menstruation. As the cycle progresses, the hormone levels change at various times. As a consequence, it is critical to research the hormonal impacts on females' otolith-ocular pathways because otherwise, the findings of oVEMP might be misinterpreted depending on the menstrual cycle's various phases. Objective: The current research set out to quantify the variations in the delay and amplitude of the oVEMP test throughout the course of three mensuration cycles. Methods: Methods: The study was conducted at Jinnah Hospital Lahore. It involved twenty females who were in good health, and their otolith-ocular systems were evaluated using oVEMP throughout the menstrual cycle. The research looked at three unique menstrual cycle phases: the monthly phase, which lasts for four days, the ovulation phase, which lasts for six days between days 12 and 17, and the luteal phase, which lasts for five days between days 18 and 22. The final evaluation was performed on days 22-28 of the same menstrual cycle. Results:oVEMP was present in each of the three menstrual cycle phases for every individual. Freidman's Chi-square test, which is nonparametric, was used on the acquired non-normal data. The findings revealed no significant differences in participants' three oVEMP recordings in terms of latency or amplitude characteristics, showing that hormonal shifts had no discernible impact on female participants' oVEMP recordings. Conclusions:It's possible to argue that using an electrical test like the oVEMP to evaluate the vestibular system won't distinguish between women depending on the timing of their menstrual cycles.
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Objectives: To investigate the properties of lateral electrode locations compared to the conventional ones and to bipolar compared to chin-referenced montages for recording ocular vestibular evoked myogenic potentials (oVEMPs).
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Objective Literature investigating otolith reflexes in patients with vestibular migraine (VM) is variable and primarily describes the descending saccular pathway. This research aimed to study ocular vestibular evoked myogenic pote...
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Objective Literature investigating otolith reflexes in patients with vestibular migraine (VM) is variable and primarily describes the descending saccular pathway. This research aimed to study ocular vestibular evoked myogenic potential (oVEMP) and cervical vestibular evoked myogenic potential (cVEMP) prevalence and response characteristics in patients with suspected VM and in control patients. The purpose is to assess vulnerabilities within the ascending utricular and descending saccular pathways in the VM population.
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Objective: Chronically increased blood glucose levels may affect the vestibular system by damaging cells and neural structures in diabetes mellitus (DM). We aimed to search the effects of neurovascular degeneration on the vestibul...
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Objective: Chronically increased blood glucose levels may affect the vestibular system by damaging cells and neural structures in diabetes mellitus (DM). We aimed to search the effects of neurovascular degeneration on the vestibular system in type 2 DM and prediabetic patients by using air-conducted ocular (oVEMP) and cervical (cVEMP) vestibular evoked myogenic potentials. Design: Prospective study. Study sample: Thirty diabetic, 30 prediabetic patients, and 31 age-and sex-matched controls having no peripheral or central vestibular disease, were enrolled. All participants were evaluated by audiovestibular tests, oVEMP, and cVEMP. Results: In the diabetic group, mean values of both oVEMP and cVEMP p1, n1 latencies were significantly longer compared to the prediabetic group and the control group, whereas latencies were similar in prediabetic and the control groups. Bilateral neural dysfunction was recognized in both tests and lateralization was not seen in VEMP asymmetric ratios. In the diabetic group, prevalence of pathological p1 and n1 latencies in oVEMP were 30.4% and 37.5%, whereas they were 53.7%, 59.3% in cVEMP, respectively. p1 latencies of cVEMP and oVEMP were positively correlated with HbA1c and fasting plasma glucose level in the diabetic group. Conclusion: Subclinical vestibular neuropathy can be a newly defined diabetes-related complication.
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BACKGROUND: The ocular vestibular evoked myogenic potential is otolith-dependent and has been suggested to be a manifestation of the linear vestibulo-ocular reflex (L-VOR). A characteristic feature of the translational LVOR (t-LVO...
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BACKGROUND: The ocular vestibular evoked myogenic potential is otolith-dependent and has been suggested to be a manifestation of the linear vestibulo-ocular reflex (L-VOR). A characteristic feature of the translational LVOR (t-LVOR) is its dependence on the distance of a target. OBJECTIVE: To assess if viewing distance affects amplitude and latency properties of the ocular vestibular evoked myogenic potential (oVEMPs). METHODS: Bone- and air-conducted (BC and AC) stimuli were used to evoke oVEMPs in 10 healthy subjects. BC stimuli consisted of impulsive accelerations applied at the mastoids, AFz, Oz and Iz. AC stimuli consisted of 500?Hz tones delivered unilaterally to each ear. Target distances of 40?cm (near), 190?cm (intermediate) and 340?cm (far) were used for all stimuli. RESULTS: The largest amplitude oVEMP was obtained from Iz and the latency for AFz was shorter than for BC stimulation at other sites. We found no significant effect of target distance on oVEMP amplitudes for any of the stimuli used. There was a small but significant effect on latency with the nearest target having a longer latency (overall 12.4?ms vs 12.0?ms for the 2 more distant sites). CONCLUSIONS: Previously reported differences between latencies and stimulus sites for midline BC stimulation were confirmed. Target distance had no significant effect on oVEMP amplitude, which suggests it is not modified like other components of the t-LVOR.
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Ocular vestibular-evoked myogenic potentials (OVEMPs) in our hands provide us with reproducible and consistent results; however, it has been shown that the OVEMP amplitude decreases with increased stimulus duration. The exact numb...
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Ocular vestibular-evoked myogenic potentials (OVEMPs) in our hands provide us with reproducible and consistent results; however, it has been shown that the OVEMP amplitude decreases with increased stimulus duration. The exact number of stimuli for OVEMP recording is not consistent among the published papers describing this test. We aimed to determine the number of stimuli needed to produce a satisfactory OVEMP response and the consequences of a more prolonged stimulation to the OVEMP response. We retrospectively analyzed 50 OVEMP patient recordings and found that the average number of sweeps carried out was 26. We carried out three different OVEMP recordings using our standard protocol of (1) a "standard" OVEMP protocol, in which we record until the OVEMP wave becomes obvious; (2) an OVEMP recording using our average of 26 sweeps; and (3) an OVEMP recording with twice as many sweeps. OVEMP latencies did not change when using different number of sweeps; however, the amplitudes showed a significant decrease with an increasing number of sweeps. OVEMPs can be completed in a satisfactory manner with a much lower number of stimuli than those usually carried out. Reducing the stimulus number reduces the time taken for the test, minimizes the cochlear insult while not reducing the valuable information obtained, and maximizes the amplitude of the stimulus, possibly increasing the accuracy of measuring interaural amplitudes and helping to measure asymmetry.
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Objective: Recently, it could be demonstrated that an increased intracranial pressure causes a modulation of the air conducted sound evoked ocular vestibular evoked myogenic potential (oVEMP). The mechanism for this modulation is ...
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Objective: Recently, it could be demonstrated that an increased intracranial pressure causes a modulation of the air conducted sound evoked ocular vestibular evoked myogenic potential (oVEMP). The mechanism for this modulation is not resolved and may depend on a change of either receptor excitability or sound energy transmission.
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