Stimulation In Healthy Subjects Research Articles

P50 potential-associated gamma band activity: modulation by distraction.

We aimed to evaluate the effect of changing attentional demands towards stimulation in healthy subjects on P50 potential-related high-frequency beta and gamma oscillatory responses, P50 and N100 peak amplitudes and their gating measures. There are no data showing effect of attention on P50 potential-related beta and gamma oscillatory responses and previous results of attention effects on P50 and N100 amplitudes and gating measures are inconclusive. Nevertheless the variation in the level of attention may be a source of variance in the recordings as well as it may provide additional information about the pathology under study. Nine healthy volunteers participated in the study. A standard paired stimuli auditory P50 potential paradigm was applied. Four stimulation conditions were selected: focused attention (stimuli pair counting), unfocused attention (sitting with open eyes), easy distraction (reading a magazine article), and difficult distraction (searching for Landolt rings with appropriate gap orientation). Time-frequency responses to both S1 and S2 were evaluated in slow beta (13-16 Hz, 45-175 ms window); fast beta (20-30 Hz, 45-105 ms window) and gamma (32-46 Hz, 45-65 ms window) ranges. P50 and N100 peak amplitudes in response to both S1 and S2 and their ratio were evaluated. The phase-locked P50 potential-associated gamma activity was attenuated during distraction tasks as compared to focused attention and an unfocused attention condition. The amplitudes and gating measures of P50 and N100 waves and beta activity were not sensitive to the competing distraction task performance. The use of a distraction task is not favorable when phase-locked gamma range activity is a key interest in auditory potential studies.

Evaluation of the immediate effects of manual acupuncture on brachial bicep muscle function in healthy individuals and poststroke patients: a study protocol of a parallel-group randomized clinical trial

Stroke is a morbid entity in Chinese medicine recognized for over 2 000 years with sensory-motor impairments reported by several classical authors. However, the majority of controlled clinical trials of acupuncture in the treatment of post stroke recovery failed to obtain significant long-term results on functional recovery. Moreover, contradictory results have been obtained regarding the immediate effects of acupuncture stimulation on the electrical activity of human skeletal muscles as observed using surface electromyography. These results raise the question of whether acupuncture has any effect on the neuromuscular level. This study aims to evaluate the immediate effects of manual acupoint stimulation on the electrical activity and strength of the biceps brachii of healthy individuals and patients with chronic hypertonic hemiparesis. The study proposes a single-blinded randomized clinical trial with four parallel groups. Healthy subjects and post stroke patients with chronic spastic hemiparesis will be submitted to a single acupuncture intervention puncturing either Quchi (LI11) or Tianquan (PC2). The immediate effects on muscle function will be assessed by surface electromyography and isometric force of the biceps brachii muscle as the primary outcome. Secondary outcomes comprise the frequency of patterns in each group, as well as the frequency distribution of manifestations. The proposed study design includes some improvements on common methodological issues on clinical trials with an integrative design. This study design is expected to provide new insights on the neuromuscular effects of acupuncture stimulation in healthy subjects and post stroke patients. Brazilian Clinical Trials Registry (www.ensaiosclinicos.gov.br) in English and Portuguese in October 2011. RBR-5g7xqh.

The Efficiency of Simultaneous Binaural Ocular Vestibular Evoked Myogenic Potentials: A Comparative Study with Monaural Acoustic Stimulation in Healthy Subjects

ObjectivesTo evaluate the test-retest reliability and convenience of simultaneous binaural acoustic-evoked ocular vestibular evoked myogenic potentials (oVEMP).MethodsThirteen healthy subjects with no history of ear diseases participated in this study. All subjects underwent oVEMP test with both separated monaural acoustic stimulation and simultaneous binaural acoustic stimulation. For evaluating test-retest reliability, three repetitive sessions were performed in each ear for calculating the intraclass correlation coefficient (ICC) for both monaural and binaural tests. We analyzed data from the biphasic n1-p1 complex, such as latency of peak, inter-peak amplitude, and asymmetric ratio of amplitude in both ears. Finally, we checked the total time required to complete each test for evaluating test convenience.ResultsNo significant difference was observed in amplitude and asymmetric ratio in comparison between monaural and binaural oVEMP. However, latency was slightly delayed in binaural oVEMP. In test-retest reliability analysis, binaural oVEMP showed excellent ICC values ranging from 0.68 to 0.98 in latency, asymmetric ratio, and inter-peak amplitude. Additionally, the test time was shorter in binaural than monaural oVEMP.ConclusionoVEMP elicited from binaural acoustic stimulation yields similar satisfactory results as monaural stimulation. Further, excellent test-retest reliability and shorter test time were achieved in binaural than in monaural oVEMP.

State-Dependent and Timing-Dependent Bidirectional Associative Plasticity in the Human SMA-M1 Network

The supplementary motor area (SMA-proper) plays a key role in the preparation and execution of voluntary movements. Anatomically, SMA-proper is densely reciprocally connected to primary motor cortex (M1), but neuronal coordination within the SMA-M1 network and its modification by external perturbation are not well understood. Here we modulated the SMA-M1 network using MR-navigated multicoil associative transcranial magnetic stimulation in healthy subjects. Changes in corticospinal excitability were assessed by recording motor evoked potential (MEP) amplitude bilaterally in a hand muscle. We found timing-dependent bidirectional Hebbian-like MEP changes during and for at least 30 min after paired associative SMA-M1 stimulation. MEP amplitude increased if SMA stimulation preceded M1 stimulation by 6 ms, but decreased if SMA stimulation lagged M1 stimulation by 15 ms. This associative plasticity in the SMA-M1 network was highly topographically specific because paired associative stimulation of pre-SMA and M1 did not result in any significant MEP change. Furthermore, associative plasticity in the SMA-M1 network was strongly state-dependent because it required priming by near-simultaneous M1 stimulation to occur. We conclude that timing-dependent bidirectional associative plasticity is demonstrated for the first time at the systems level of a human corticocortical neuronal network. The properties of this form of plasticity are fully compatible with spike-timing-dependent plasticity as defined at the cellular level. The necessity of priming may reflect the strong interhemispheric connectivity of the SMA-M1 network. Findings are relevant for better understanding reorganization and potentially therapeutic modification of neuronal coordination in the SMA-M1 network after cerebral lesions such as stroke.

Changes of Blood Flow Volume in the Superior Mesenteric Artery and Brachial Artery with Abdominal Thermal Stimulation

In traditional Chinese medicine, moxibustion is a local thermal therapy that is used for several conditions. Quantifying the effects of moxibustion therapy has been difficult because the treatment temperature depends on the physician's experience, and the temperature distribution in the target area is not uniform. This prospective observational study aims to quantify the effect of local thermal stimulation to the abdomen. We developed a heat transfer control device (HTCD) for local thermal stimulation. Twenty-four healthy subjects were enrolled and they underwent abdominal thermal stimulation to the para-umbilical region with the device for 20 min. Blood flow volume in the superior mesenteric artery (SMA) and brachial artery (BA), the heart rate and the blood pressure were measured at rest, 15 min after starting thermal stimulation and 10, 20, 30 and 40 min after completing thermal stimulation. Blood flow parameters were measured by high-resolution ultrasound. In the SMA, blood flow volume was significantly increased during thermal stimulation (P < .01), as well as at 10 min (P < .01) and 20 min (P < .05) after stimulation. In the BA, blood flow volume decreased at 40 min after stimulation (P < .01). In conclusion we could quantify the effect of local thermal stimulation with an HTCD and high-resolution ultrasound. Thermal stimulation of the para-umbilical region increased blood flow in the SMA 20 min after stimulation in healthy subjects.

Interocular amplitude differences of multifocal electroretinograms obtained under monocular and binocular stimulation conditions

To compare the interocular amplitude differences of the multifocal electroretinograms (mfERGs) evoked by either monocular or binocular stimulation in healthy subjects with good vision. Thirty-five subjects were included in the study. A Roland Consult RETIscan system was used. DTL electrodes were employed. First, the right and left eyes were stimulated separately, then, binocular stimulation was applied. The amplitudes of the scalar products were averaged over five concentric retinal regions (rings). The interocular amplitude differences were 21.55% (SD: ±12.72) under monocular conditions and 18.69% (SD: ±11.64) under binocular conditions. No significant differences were found between the amplitudes and variability values obtained under either monocular or binocular stimulation. Our results provided no evidence for the advantage of either binocular or monocular stimulating conditions in obtaining mfERGs. A considerable side difference was found between the mfERGs of the two eyes in almost all individual cases.

Determinants of the induction of cortical plasticity by non‐invasive brain stimulation in healthy subjects

The ability to induce cortical plasticity with non-invasive brain stimulation (NBS) techniques has provided novel and exciting opportunities for examining the role of the human cortex during a variety of behaviours. Additionally, and importantly, the induction of lasting changes in cortical excitability can, under some conditions, reversibly modify behaviour and interact with normal learning. Such findings have driven a large number of recent studies examining whether by using such approaches it might be possible to induce functionally significant changes in patients with a large variety of neurological and psychiatric conditions including stroke, Parkinson's disease and depression. However, even in neurologically normal subjects the variability in the neurophysiological and behavioural response to such brain stimulation techniques is high. This variability at present limits the therapeutic usefulness of these techniques. The cause of this variability is multifactorial and to some degree still unknown. However, a number of factors that can influence the induction of plasticity have been identified. This review will summarise what is known about the causes of variability in healthy subjects and propose additional factors that are likely to be important determinants. A greater understanding of these determinants is critical for optimising the therapeutic applications of non-invasive brain stimulation techniques.

Changes of blood flow volume in the superior mesenteric artery and brachial artery with abdominal thermal stimulation

Background In traditional Chinese medicine, moxibustion is a local thermal therapy that is used for several conditions. Quantifying the effects of moxibustion therapy has been difficult because the treatment temperature depends on the physician's experience, and the temperature distribution in the target area is not uniform. Aims This prospective observational study aims to quantify the effect of local thermal stimulation to the abdomen. Methods We developed a heat transfer control device (HTCD) for local thermal stimulation. Twenty-four healthy subjects were enrolled and they underwent abdominal thermal stimulation to the para-umbilical region with the device for 20 min. Blood flow volume in the superior mesenteric artery (SMA) and brachial artery, the heart rate, and the blood pressure were measured at rest, 15 min after starting thermal stimulation, and 10, 20, 30, and 40 min after completing thermal stimulation. Blood flow parameters were measured by high-resolution ultrasound. Results In the SMA, blood flow volume was significantly increased during thermal stimulation ( p p p p Conclusions We could quantify the effect of local thermal stimulation with an HTCD and high-resolution ultrasound. Thermal stimulation of the para-umbilical region increased blood flow in the SMA 20 min after stimulation in healthy subjects.

Cognitive modulation of endocrine responses to CRH stimulation in healthy subjects

The hypothalamic-pituitary adrenal (HPA) axis is critical for biobehavioral adaptation to challenge and appears dysregulated in a range of psychiatric disorders. Its precise role in psychopathology remains unclear and discrepant and difficult to explain findings abound in the clinical literature. Basic research suggests this system is sensitive to psychosocial cues, but psychosocial milieu factors are rarely controlled or examined in psychiatric studies using biological probes of the HPA axis. To test the hypothesis that psychological factors might complicate HPA study results even in direct, pharmacological challenge paradigms, endocrine responses to corticotropin-releasing hormone (CRH) were examined under two different cognitive preparation conditions. Healthy subjects (n=32) received standard instructions or a cognitive intervention (CI) prior to injection with CRH and placebo, given on separate days in random order. The CI combined access to control over drug exposure with novelty reduction and coping enhancement. Blood samples were obtained via intravenous catheter before and after CRH. Cognitive intervention reduced corticotropin (ACTH) levels, but only when CRH was given first (intervention by order interaction). It did not reduce cortisol response. The CI and visit (1st or 2nd) both impacted cortisol levels on placebo day. Modifiable psychological factors may amplify or inhibit HPA axis activity in pharmacological activation paradigms, including CRH stimulation tests. The factors manipulated by the CI (novelty/familiarity, control and coping) may have particular salience to the HPA axis. Differential sensitivity to such factors could impact results in studies applying biological HPA probes to psychiatric populations.

Levodopa does not enhance the effect of low-frequency repetitive transcranial magnetic stimulation in tinnitus treatment

Objective: Low-frequency repetitive transcranial magnetic stimulation (rTMS) has shown promise for the treatment of tinnitus. Experimental data from motor cortex stimulation in healthy subjects indicates that the suppressing effect of low-frequency rTMS can be enhanced by dopaminergic receptor activation. Here we investigated whether administration of the dopamine precursor Levodopa before low-frequency rTMS enhances its efficacy in tinnitus treatment.

Effects of combined inhibitory and excitatory theta-burst stimulation in healthy subjects

Effects of combined inhibitory and excitatory theta-burst stimulation in healthy subjects

Effects of Gaze Positions on Ocular Vestibular Evoked Myogenic Potentials

Background and Objectives：Recent works have demonstrated the existence of ocular vestibular evoked myogenic potentials (OVEMPs), which reflects otolith-ocular reflex. The purpose of this study was to identify an appropriate gaze position to detect OVEMPs produced by air-conducted sound stimulation in healthy subjects. Subjects and Method：Twenty four healthy subjects (35 ears) were included in this study. Surface electromyographic activity was recorded from active electrodes placed inferior to each eye. Stimulation with 500 Hz short tone bursts was used to activate the vestibular end-organs. Results：Sound stimulation evoked negative-positive biphasic responses on both ipsilateral and contralateral eyes, while responses were contralateral eye-dominant. Contralateral eye responses had higher response incidence and larger amplitudes. Altering the direction of gaze generally changed the incidence and size of the inter-peak amplitudes. The higher incidence and larger amplitudes were recorded when the eyes are directed to the superior and ipsilateral side to the sound stimulation. In that gaze position, the amplitude was 5.3 μV, the first negative peak latency was 10.5 ms and the following positive peak latency was 15.4 ms on the average. Conclusion：OVEMPs can be evoked using an air-conducted 500 Hz tone burst and are best recorded contralaterally with a upward gaze towards the source of sound stimulation. Further changes of the test parameters are needed for higher and consistent responses. (Korean J Otorhinolaryngol-Head Neck Surg 2009;52:215-9)

Levodopa does not enhance the effect of low-frequency repetitive transcranial magnetic stimulation in tinnitus treatment

Low-frequency repetitive transcranial magnetic stimulation (rTMS) has shown promise for the treatment of tinnitus. Experimental data from motor cortex stimulation in healthy subjects indicate that the suppressing effect of low-frequency rTMS can be enhanced by dopaminergic receptor activation. Here we investigated whether administration of the dopamine precursor levodopa before low-frequency rTMS enhances its efficacy in tinnitus treatment. Sixteen patients with chronic tinnitus received 100 mg of levodopa before each session of low-frequency rTMS. Results were compared with a matched control group of 16 patients who received the same treatment, but without levodopa. Treatment outcome was assessed with a standardized tinnitus questionnaire. Both stimulation protocols resulted in a significant reduction of tinnitus scores after 10 days of stimulation; however, there was no significant difference between the two groups. Our data suggest that 100 mg of levodopa does not enhance the effect of rTMS in the treatment of tinnitus.

Motor Potentials Evoked by Navigated Transcranial Magnetic Stimulation in Healthy Subjects

Navigated transcranial magnetic stimulation (TMS) is a tool for targeted, noninvasive stimulation of cerebral cortex. Transcranial stimuli can depolarize neurons and evoke measurable effects which are unique in two ways: the effects are caused directly and without a consciousness of the subject, and, the responses from peripheral muscles provide a direct measure for the integrity of the whole motor pathway. The clinical relevance of the method has not always been fully exposed because localizing the optimal stimulation site and determining the optimal stimulation strength have been dependent on time-consuming experimentation and skill. Moreover, in many disorders it has been uncertain, whether the lack of motor responses is the result of true pathophysiological changes or merely because of unoptimal stimulation. We characterized the muscle responses from human primary motor cortex system by navigated TMS to provide normative values for the clinically relevant TMS parameters on 65 healthy volunteers aged 22 to 81 years. We delivered focal TMS pulses on the primary motor area (M1) and recorded muscle responses on thenar and anterior tibial muscles. Motor threshold, latencies and amplitudes of motor-evoked potentials, and silent period duration were measured. The correction of the motor-evoked potential latency for subjects' height is provided. In conclusion, we provide a modified baseline of TMS-related parameters for healthy subjects. Earlier such large-scale baseline material has not been available.

Cigarette smoking leads to reduced relaxant responses of the cutaneous microcirculation

Smoking is a major risk factor for cardiovascular disease. The present study was undertaken to examine if cigarette smoking translates into reduced relaxant responses of the peripheral microcirculation. The cutaneous forearm blood flow was measured by laser Doppler flowmetry. The vasodilator response to the iontophorectic administration of acetylcholine (ACh), acting via an endothelial mechanism, and sodium nitroprusside (SNP), and acting via a smooth muscle mechanism were studied. The study population consisted of 17 nonsmokers and 17 current smokers (mean age 64+/-2 years, 13 females and 4 males) in each matched group. There was no difference between the groups in baseline characteristics or in basal flow. Smokers showed however significantly reduced responses to both ACh (mean +/- SEM, from 973+/-137% in nonsmokers to 651+/-114% in smokers, p<0.05) and SNP (from 575+/-111% in nonsmokers to 355+/-83% in smokers, p<0.05). The response to the local heating (44 degrees C) was reduced in smokers (from 1188+/-215% in nonsmokers to 714+/-107% in smokers, p<0.01). In addition, there was no difference between men and women within the groups. The data show that cigarette smoking results in reduced peripheral microvascular responses to both endothelial and smooth muscle cell stimulation in healthy subjects, suggesting a generalized microvascular vasomotor function.

Pancreatic Perfusion: Noninvasive Quantitative Assessment with Dynamic Contrast-enhanced MR Imaging without and with Secretin Stimulation in Healthy Volunteers—Initial Results

To prospectively quantify pancreatic regional perfusion with dynamic contrast material-enhanced magnetic resonance (MR) imaging by using a one-compartment model and to assess perfusion changes during secretin stimulation in healthy volunteers. The study had institutional review board approval, and written informed consent was obtained. Ten healthy volunteers (five men, five women; mean age, 24.7 years +/- 1.9 [standard deviation]; range, 22-29 years) underwent MR imaging pancreatic perfusion studies performed twice without secretin and twice during secretin stimulation. Dynamic contrast-enhanced MR imaging consisted of saturation-recovery T1-weighted turbo-field-echo imaging with peripheral pulse triggering and respiratory tracking. A dose of 0.05 mmol gadodiamide per kilogram of body weight was injected at a rate of 3.5 mL/sec. Regional perfusion parameters were fitted with a one-compartment model. The analysis of variance test for repeated measurements was used to assess differences in pancreatic perfusion without and that with secretin administration. Significant differences in perfusion parameters between the three pancreatic regions were observed (P < .05). During secretin stimulation, a significant difference was observed only between the body and the tail of the pancreas (P = .02). A significant increase (P = .003) in pancreatic perfusion was observed after secretin administration. Mean pancreatic perfusion was 184 mL/min/100 g of tissue +/- 71, 207 mL/min/100 g +/- 77, and 230 mL/min/100 g +/- 87 without secretin and 342 mL/min/100 g +/- 154, 338 mL/min/100 g +/- 156, and 373 mL/min/100 g +/- 176 after secretin stimulation in the head, body, and tail of the pancreas, respectively. Intraindividual variability was 21% without secretin stimulation and 46% with secretin stimulation. Dynamic contrast-enhanced MR imaging enables noninvasive quantification of regional pancreatic perfusion in resting conditions and demonstrates the increase in pancreatic perfusion during secretin stimulation in healthy subjects.

Spinothalamic tract conduction velocity estimated using contact heat evoked potentials: What needs to be considered

Objective Laser-evoked potentials have been shown to be clinically useful for the electrophysiological assessment of nociceptive pathways. Contact heat evoked potentials (CHEP) are less established but might be advantageous for clinical purposes. This study aimed at determining the conduction velocity (CV) of central pain (spinothalamic tract, STT) pathways using contact heat stimulation in order to replicate previous findings using laser stimulation. Methods Contact heat stimulation 3 °C higher than the pain threshold was applied at different body locations in 20 subjects. Results The CHEP latencies correlated significantly with the respective pain thresholds. Without normalization for this effect no significant linear regression between distance to the brain and the latencies was found. Conversely, if thresholds were considered, the regression was significant and the CV of the STT (ranging between 11.2 and 13.4 m/s) was comparable to CVs estimated after laser stimulation. Conclusions Pain thresholds seem crucial in interpreting CHEP latencies. It is suggested that the rather low heating rate is responsible for the dependence of latencies on the pain thresholds. Significance This study shows the importance of pain thresholds and their control to attain valid CV of the STT after contact heat stimulation in healthy subjects.

Effects of attention on inhibitory and facilitatory phenomena elicited by paired-pulse transcranial magnetic stimulation in healthy subjects

We investigated whether human attentional processes influence the activity of intracortical inhibitory and excitatory circuits--short-interval intracortical inhibition (SICI), long-interval intracortical inhibition (LICI), and the intracortical facilitation (ICF)--elicited by paired-pulse transcranial magnetic stimulation (TMS) in healthy subjects. In eight healthy subjects we tested SICI, LICI and ICF under different attention-demanding conditions: "relaxed", "target hand" and "non-target hand". To compare the effects of attentional levels on SICI, LICI and ICF with those produced on the MEPs elicited by repetitive TMS (rTMS), in the same subjects we also delivered supra-threshold 5-Hz rTMS under the same three experimental conditions. To disclose whether attentional processes act selectively on circuits engaged by TMS delivered at 5 Hz frequency and at an interstimulus interval (ISI) of 200 ms, we also investigated the effects of different attention levels on paired-pulse TMS delivered at the 200 ms ISI and on the MEP size during 1-Hz rTMS. Attentional levels had no influence on SICI, ICF and LICI activated by paired-pulse TMS, but increased the MEP facilitation elicited by 5-Hz rTMS. Varying the attention level left the findings from 1-Hz rTMS unchanged. The finding that attention leaves the activity of intracortical inhibitory and excitatory circuits elicited by paired-pulse TMS unchanged but influences the MEP facilitation elicited by 5-Hz rTMS suggests that attention operates only when the stimulation entrains neural circuits made up of a large number of cortical cells with plasticity properties.

High-frequency priming stimulation does not enhance the effect of low-frequency rTMS in the treatment of tinnitus

Based on its ability to reduce the excitability of the cortex locally, low-frequency repetitive transcranial magnetic stimulation (rTMS) has been investigated for the treatment of hyperexcitability disorders such as auditory hallucinations and tinnitus. Results are promising, but characterized by only moderate improvement and a high inter-individual variability. Experimental data from motor cortex stimulation in healthy subjects indicates that the depressant effect of low-frequency rTMS can be enhanced by high-frequency priming stimulation. Here we will investigate whether high-frequency priming also improves the therapeutic efficacy of low-frequency rTMS in a clinical application. 32 patients with chronic tinnitus were randomly assigned to either a standard protocol of low-frequency rTMS (110% motor threshold, 1 Hz, 2000 stimuli/day) or a stimulation protocol in which priming stimulation with 6 Hz (90% motor threshold, 960 stimuli) preceded low-frequency rTMS (110% motor threshold, 1 Hz, 1040 stimuli/day). Stimulation was applied over the left auditory cortex by using MRI-guided coil positioning. The treatment outcome was assessed with a standardized tinnitus questionnaire. There was no significant difference between the standard protocol and the protocol involving priming stimulation. Both stimulation protocols resulted in significant clinical improvement after 10 days of stimulation, as compared to baseline. Our data does not support an enhancing effect of higher frequency priming on low-frequency rTMS in the treatment of tinnitus.

Vestibular-evoked extraocular potentials by air-conducted sound: Another clinical test for vestibular function

Objective The purpose of this study was to identify an appropriate way to detect vestibular-evoked extraocular potentials (oVEMPs) produced by air-conducted sound stimulation in healthy subjects and to apply this test clinically in patients with various vestibular disorders. Methods Ten healthy subjects were included in this study. Surface electromyographic (EMG) activity was recorded from active electrodes placed on the face just inferior to each eye. Stimulation with 0.1 ms clicks and 500 Hz short tone bursts was used to activate the vestibular end-organs in healthy subjects. We also tested 12 patients with unilateral vestibular disorders using 500 Hz short tone bursts. Results In healthy subjects, negative–positive biphasic responses with short latency by air-conducted click (the first negative peak latency = 8.8 ms and the following positive peak latency = 14.5 ms on the average) (oVEMP) were only identified beneath the eye contralateral to the stimulating ear. On the other hand, stimulation with 500 Hz short tone bursts evoked negative–positive biphasic responses (the first negative peak latency = 10.5 ms and the following positive peak latency = 15.9 ms on the average) on both ipsilateral and contralateral eyes, while responses were contralateral eye-dominant. Contralateral eye responses by 500 Hz short tone bursts had higher response prevalence and larger amplitudes than clicks. In patients, oVEMPs evoked by the affected side stimulation tended to decrease or lacked a response. The presence of oVEMPs and cVEMPs coincided well in patients when 500 Hz short tone bursts were presented. Conclusions oVEMPs can be evoked using air-conducted 500 Hz tone burst and are best recorded contralaterally on upgaze. Significance oVEMPs by air-conducted sounds could be a useful alternative clinical test for patients with vestibular lesions.