Ocular Vestibular Myogenic Potentials Research Articles

Genç Erişkinlerde Servikal ve Oküler Vestibüler Uyarılmış Miyojenik Potansiyellerin Normatif Değerleri

Genç Erişkinlerde Servikal ve Oküler Vestibüler Uyarılmış Miyojenik Potansiyellerin Normatif Değerleri

The Effect of Elevated Intracranial Pressure on Frequency Tuning of Air-Conducted Ocular Vestibular Myogenic Potentials in Ménière's Disease Patients.

To investigate the effect of increased intracranial pressure on ocular vestibular-evoked myogenic potential (oVEMP) amplitudes and frequency tuning in patients with Ménière's disease (MD) to elucidate whether oVEMPS recorded under such conditions could provide a simple and accurate diagnostic test for MD. Tertiary referral center for otology and neurotology. Ten patients with certain unilateral MD (mean age = 48.2 yr, range 25-75 yr, 6 males and 4 females) as confirmed by a locally enhanced inner ear MRI (LEIM) were enrolled in this study. Air-conducted tone-burst oVEMP amplitudes were measured in response to 500 Hz and 1000 Hz in the horizontal plane (0 degree), a 20-degree head-down position. Tilting the patients from the horizontal position to the 20-degree head-down position led to a large reduction in oVEMP amplitudes to the 500 Hz tone burst (3.02 μV vs 1.17 μV, p = 0.005) and to a smaller one in the 1000 Hz tone burst (2.28 μV vs 1.78 μV, p = 0.013) in the Ménière's ear. Accordingly, the 500/1000 Hz frequency-tuning ratio was significantly decreased in the Ménière's ear as a result of this manoeuver (1.36 vs 0.75, p = 0.005). oVEMP amplitudes and frequency tuning in MD patients show a similar behavior to that found in healthy control subjects. oVEMP testing of putative MD patients in the tilted position is therefore unlikely to be diagnostically useful.

Vestibular Evoked Myogenic Potentials in Vestibular Migraine: Do They Help Differentiating From Menière's Disease?

To investigate whether both cervical and ocular vestibular myogenic potentials (cVEMPs and oVEMPs) to air-conducted sound (ACS) and bone-conducted vibration (BCV) can help to differentiate vestibular migraine (VM) and Menière's disease (MD). Retrospective study. A tertiary referral center. Twenty-eight patients with VM, 28 patients with definite unilateral MD, and 28 age-matched controls were included. Cervical VEMPs to 500 Hz ACS (cVEMPs-air) and 500 Hz BCV (cVEMPs-bone), oVEMPs to 500 Hz ACS (oVEMPs-air) and 500 Hz BCV (oVEMPs-bone), and caloric tests were performed. Results of these vestibular function tests were compared between the groups. The prevalence of abnormality was significantly higher in VM than in controls only for the caloric test (P < .05). Asymmetry ratios (ARs) for cVEMPs-air and oVEMPs-air were significantly larger in VM than in controls (P < .05). Between VM and MD, the prevalence of abnormality was significantly different only for oVEMPs-air. The ARs for oVEMPs-air and caloric test asymmetries were significantly smaller in VM than in MD (P < .05). Among the vestibular function tests, oVEMPs-air may be most helpful for the differentiation of VM from MD as a group.

Ocular vestibular evoked myogenic potentials in response to air-conducted 500 Hz short tones: Effect of stimulation procedure (monaural or binaural), age and gender.

The ocular vestibular myogenic potentials (oVEMP) can be elicited by monaural air-conducted sound stimulation, and are usually recorded from the contralateral eye. In clinical setting a binaural stimulation would save time and require less effort from the subjects. We evaluated the differences between monaural and binaural stimulation, and the possible effect of age and gender on oVEMP parameters. Air-conducted oVEMP were recorded by binaural and by monaural stimulation in a group of 54 normal subjects, aged from 12 to 83 years, and in 50 vestibular patients. From each side, we measured the latency of the N1 component, and the peak-to-peak N1-P1 amplitude. For both parameters we also computed the asymmetry ratio. In normal subjects binaural stimulation produced slightly larger responses than monaural stimulation; detectability, latency and amplitude ratio were the same for the two techniques. We found no differences related to gender, and the age-induced amplitude decline was likely to be negligible.oVEMP recorded not in an acute phase of their disorder, proved to be abnormal in about 20% of the patients, and the normal or abnormal findings obtained either with monaural or with binaural stimulation were always concordant. The oVEMP obtained after binaural and monaural stimulation are very similar, and they are largely independent from age and gender.

Selective changes of ocular vestibular myogenic potentials in Parkinson's disease.

Vestibular evoked myogenic potentials represent electrophysiological tools to measure vestibular reflex actions at different levels of the brainstem in Parkinson's disease. To investigate cervical and ocular vestibular myogenic potentials in Parkinsonian patients with mild disability. In 13 Parkinsonian patients and 13 age-matched healthy controls, cervical and ocular vestibular myogenic potentials were recorded after unilateral air-conducted tone bursts and bone-conducted stimuli delivered at the forehead or mastoids. In contrast to relatively preserved cervical vestibular evoked myogenic potentials, ocular vestibular evoked myogenic potentials were significantly delayed and of reduced amplitude, particularly after impulsive stimulation in Parkinsonian patients. Levodopa had no significant effect on either type of response. In mild to moderate Parkinson's disease, altered ocular vestibular myogenic potentials may indicate early functional involvement of the upper brainstem, in contrast to preserved lower brainstem function as reflected by normal cervical vestibular myogenic potentials.

Ocular vestibular-evoked myogenic potentials (oVEMPs) in response to bone-conducted vertex vibration

ObjectiveTo investigate low-frequency vertex bone-conducted (BC) vibration for evoking ocular vestibular myogenic potentials (oVEMPs) and its ability to discriminate between lesioned and healthy ears. MethodsoVEMPs were analysed in response to 125-Hz single cycle vertex BC vibration in healthy subjects (n=50) and in patients with severe unilateral vestibular loss (n=10). Both positive and negative initial stimulus motions were used. ResultsIn most healthy subjects, vertex BC vibration oVEMPs was successfully and symmetrically evoked from both ears. The response was dependent on the direction of the stimulus motion. The latency was shorter with negative initial stimulus motion; however, a positive initial stimulus motion generated somewhat larger amplitudes. Furthermore, there was no significant response from lesioned ears, whereas oVEMPs from the patients’ healthy ears were similar to the responses in healthy subjects. ConclusionThe oVEMP low-frequency BC response was dependent on the direction of the initial stimulus motion. Testing oVEMPs in response to low-frequency vertex vibration can discriminate patients with unilateral vestibular function loss from healthy controls. SignificanceLow-frequency vertex BC vibration oVEMPs should be considered a possible clinical screening test to evaluate vestibular function.

Comparison of Cervical and Ocular Vestibular Evoked Myogenic Potentials in Dancers and Non-Dancers.

The objective of the study was to assess the sacculocollic and otolith ocular pathway function using cervical vestibular evoked myogenic potentials (cVEMP) and ocular vestibular myogenic potentials (oVEMP) in dancers and non dancers. Total 16 subjects participated in the study. Out of 16 participants, 8 were trained in Indian classical form of dance (dancers) and other 8 participants who were not trained in any dance form (non dancers). cVEMP and oVEMP responses were recorded for all the subjects. Non Parametric Mann-Whitney U test revealed no significant difference between dancers and non dancers for the latency and amplitude parameter for cVEMP and oVEMP, i.e. P13, N23 latency and P13-N23 complex amplitude and N10, P14 latency, N10-P14 complex amplitude respectively. The vestibular system comprises of several structures. It is possible that the dance style practiced by the dancer’s group assessed in this study does not contribute towards improving the plasticity of the sacculocollic and otolith-ocular pathways. It can be concluded that not all forms of dance training brings about a change in the plasticity of the sacculocollic and otolithocular pathways.

UŻYTECZNOŚĆ MIOGENNYCH PRZEDSIONKOWYCH POTENCJAŁÓW WYWOŁANYCH W DIAGNOSTYCE CHOROBY MENIERE’A: PRZEGLĄD

Meniere’s disease is an inner ear disorder characterized by aural fullness, spontaneous attacks of vertigo, fluctuating low-frequency sensorineural hearing loss and tinnitus. There are various tests such as puretone audiometry, electrocochleography, glycerol test, Caloric test, Cochlear hydrops analysis masking which have been utilised in diagnosing the Meniere’s disease. Recently cervical vestibular evoked myogenic potentials and ocular vestibular myogenic potentials have been utilised to measure the functioning of the sacculocollic and otolith ocular pathway respectively. The objective of the present study is to provide an overview of the cervical and ocular vestibular evoked myogenic potentials tests findings in individuals with Meniere’s disease.

Spontaneous Plugging of the Horizontal Semicircular Canal With Reversible Canal Dysfunction and Recovery of Vestibular Evoked Myogenic Potentials

To evaluate the clinical pathophysiology of oculomotor changes in a patient presenting with a spontaneous semicircular horizontal canal plug. A 42-year-old man with acute spontaneous vertigo with spinning and persistent left-horizontal nystagmus, intensity but not direction dependent on head orientation with respect to gravity, indicating a benign paroxysmal positional vertigo due to otoconia causing a plug in the horizontal semicircular canal. Electrophysiological and video-oculographic testing; vestibular rehabilitation. Cervical and ocular vestibular evoked myogenic potentials (VEMPs); video head impulse testing. The video head-impulse test revealed an eye velocity cutoff at 80°/s in the time interval from 40 to 90 ms after initiation of head impulses to the right. This normalized within 2 days after liberatory maneuvers, documenting for the first time a reversible deficiency of the cupular-endolymph high-frequency system dynamics. Cervical and ocular vestibular myogenic potentials were absent during stimulation of the affected side before the liberatory maneuvers but normalized within 30 to 80 days. This case is special in 4 respects: 1) nystagmus intensity, but not direction, was dependent on head orientation with respect to gravity, indicating a horizontal canal plug; 2) VEMPs were asymmetrical before liberatory maneuvers; 3) VEMPs recovered after Day 30; and 4) video head-impulse test asymmetry recovered. These observations challenge the common belief that VEMPs are evoked by otolith stimulation only. Instead, the assumption of a reversible canal dysfunction by a plug offers a more plausible explanation for all effects.