Does Electrode Impedance Affect the Recording of Ocular Vestibular-Evoked Myogenic Potentials?

2014 ◽  
Vol 25 (10) ◽  
pp. 969-974 ◽  
Author(s):  
Rachael L. Taylor ◽  
Mikael Schulin ◽  
Samanthi Goonetilleke ◽  
Miriam S. Welgampola
Keyword(s):  
Repeated Measures ◽  
Isopropyl Alcohol ◽  
Skin Surface ◽  
Estimating Equation ◽  
Vestibular Evoked Myogenic Potentials ◽  
Electrode Impedance ◽  
Vestibular Evoked Myogenic Potential ◽  
Skin Preparation ◽  
Skin Abrasion ◽  
Stimulus Artifact

Background: In evoked potential testing, it is common practice to abrade the skin surface as a means of reducing and balancing electrode impedance. The effects of skin preparation and electrode impedance on ocular vestibular-evoked myogenic potential (oVEMP) prevalence and amplitudes are not known. Purpose: We sought to determine whether comparable oVEMP waveforms could be recorded without excessive skin preparation. Research Design: This was a prospective study with a repeated-measures (within-subjects) design. Study Sample: The study group comprised 20 healthy participants (12 females and 8 males) ages 21–57 yr. Data Collection and Analysis: oVEMP reflexes were recorded in response to air-conducted and bone-conducted (AC and BC) stimuli in three conditions. In the first condition (no skin preparation), electrodes were simply placed over the skin surface. For the second condition (moderate skin preparation), oVEMP testing was repeated after the skin had been prepared with 70% isopropyl alcohol swabs. oVEMPs recorded in these two conditions were then compared with those recorded using a third conventional protocol whereby the skin was abraded with skin preparation gel until electrode impedances were low and balanced. For BC stimuli, reflex amplitudes and latencies were compared using a repeated-measures general linear model. For AC stimuli, rates of reflex detection were analyzed using a generalized estimating equation. Nonparametric Friedman tests were used to compare AC oVEMP amplitudes across the three conditions. Results: There was no significant effect of electrode impedance on reflex amplitudes, latencies, or rates of detection (p > 0.05). The results indicated significant stimulus-related artifact (≥3 μV) in 25 of 40 recordings under the high-impedance condition in response to BC stimulation. The stimulus artifact was detectable in 12 of 40 recordings after moderate skin preparation and in 5 recordings after skin abrasion. Conclusions: Comparable rates of reflex detection and oVEMP amplitudes were recorded in the three conditions, implying that rigorous rubbing of the facial skin is largely unnecessary in clinical oVEMP testing. However, for oVEMPs recorded in response to a single-polarity stimulus, reducing and balancing electrode impedances with either isopropyl alcohol wipes or skin abrasion may help reduce unwanted stimulus artifact.

Jendrassik Maneuver Facilitates cVEMP Amplitude: Some Preliminary Observations

2014 ◽  
Vol 25 (03) ◽  
pp. 237-243
Author(s):  
Lauren Roberts ◽  
Anthony T. Cacace
Keyword(s):  
Head Trauma ◽  
Repeated Measures ◽  
Neurological Disease ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
Experimental Conditions ◽  
Hearing Sensitivity ◽  
History Of ◽  
Post Hoc ◽  
Jendrassik Maneuver

Background: The cervical vestibular evoked myogenic potential (cVEMP) is an acoustically driven electrophysiological measure of saccular and inferior nerve function that requires tonic sternocleidomastoid muscle (SCM) activity in order to be elicited. The cVEMP is gaining increased interest in the clinical and research communities based on the anatomical specificity it adds to vestibular test batteries, because it is noninvasive, and since it can be performed with instrumentation commonly found in audiology clinics worldwide. Purpose: Because maintaining a constant level of tonic background electromyography (EMG) over the entire course of the recording epoch is a requirement for response elicitation, active participation for some individuals including the elderly and those with cervical problems can be difficult. As a way to facilitate the response for some clinical populations, this study addressed whether cVEMPs could be modulated by remote or local changes in EMG related neural activity by applying various maneuvers during the course of the recording epoch. Research Design: Keeping acoustic stimulation and recording parameters constant, three separate experimental conditions, Jendrassik maneuver, jaw (teeth) clenching, and forced-eye closure, were used to determine whether cVEMP amplitudes could be enhanced from the control condition. Study Sample: Nine adults (2 males; 7 females) ranging in age from 24 to 42 yr with normal pure-tone hearing sensitivity and a negative history of otological disease, neurological disease, and head trauma. Data Collection and Analysis: Cervical vestibular evoked myogenic potentials were recorded from the SCM using surface electrodes in response to suprathreshold 500 Hz Blackman windowed tone bursts under a control and three experimental conditions. Three separate one-way repeated measures analyses of variance (ANOVAs) were used to evaluate the effects of these maneuvers on P1/N1 peak-to-peak amplitudes and P1 and N1 peak latencies. Results: A significant main effect of experimental condition was shown to increase P1/N1 peak-to-peak cVEMP amplitude. Post hoc analysis found that Jendrassik maneuver versus control was the only the condition that produced significantly increased response amplitudes in comparison to all other post hoc contrasts. P1 and N1 peak latencies were unchanged across the various experimental conditions. Conclusions: In adults with normal hearing sensitivity and a negative history of otological disease, neurological disease, and head trauma, Jendrassik maneuver increased cVEMP amplitude by over 39% in comparison to the control condition. Such a simple modulation effect warrants further investigation for application in clinical studies.

scholarly journals State-of-the-art assessment allows for improved vestibular evoked myogenic potential test-retest reliability

2018 ◽  
Vol 8 (2) ◽  
Author(s):  
Lydia Behtani ◽  
Maxime Maheu ◽  
Audrey Delcenserie ◽  
Mujda Nooristani ◽  
François Champoux
Keyword(s):  
State Of The Art ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
Retest Reliability ◽  
Vestibular Assessment ◽  
Myogenic Responses ◽  
Neurologically Normal ◽  
Test Retest Reliability ◽  
The Impact ◽  
Potential Test

The goal of the present study was to evaluate the test-retest reliability values of myogenic responses using the latest guidelines for vestibular assessment. Twenty-two otologically and neurologically normal adults were assessed twice, on two different days. The analyses were carried out using interclass correlations. The results showed that the latest recommendations for vestibular assessment lead to test-retest reliability values that are as high, or greater, than those reported in previous studies. The results suggest that state-of-the-art testing, using the latest recommendations as well as electromyography control, improves reliability values of myogenic responses, more specifically for the cervical vestibular evoked myogenic potentials. The impact of small differences in experimental procedures on the reliability values of myogenic responses is also addressed.

Association of magnesium intake with sleep duration and sleep quality: findings from the CARDIA study

SLEEP ◽  
2021 ◽  
Author(s):  
Yijia Zhang ◽  
Cheng Chen ◽  
Liping Lu ◽  
Kristen L Knutson ◽  
Mercedes R Carnethon ◽  
...  
Keyword(s):  
Sleep Quality ◽  
Sleep Duration ◽  
Repeated Measures ◽  
Depressive Disorders ◽  
Estimating Equation ◽  
Dietary History ◽  
Short Sleep ◽  
Randomized Controlled ◽  
Depression Status ◽  
Intake Ratio

Abstract Study Objectives As an antagonist of calcium (Ca), magnesium (Mg) has been implicated in the regulation of sleep. We aimed to examine the longitudinal associations of Mg intake and Ca-to-Mg intake ratio (Ca:Mg) with sleep quality and duration. Methods The study sample consisted of 3,964 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary and supplementary intake of Mg were obtained using the CARDIA Dietary History at baseline (1985–1986), exam years 7 and 20. Self-reported sleep outcomes were measured at years 15 and 20. Sleep quality was rating from 1 (very good) to 5 (very bad). We categorized sleep duration to <7, 7–9, and >9 h. Generalized estimating equation was used to examine the associations of interest as repeated measures at the two time points. Results After adjustment for potential confounders, Mg intake was borderline associated with better sleep quality [highest quartile (Q4) vs. intake quartile (Q1): odds ratio (OR) = 1.23; 95% CI = 0.999, 1.50, ptrend = 0.051]. Participants in Q4 were also less likely to have short sleep (<7 h) compared to those in Q1 (OR = 0.64; 95% CI = 0.51, 0.81, ptrend = 0.012). The observed association with short sleep persisted among participants without depressive disorders (Q4 vs. Q1: OR = 0.64; 95% CI = 0.49, 0.82, ptrend < 0.001), but not among individuals with depressive disorder. Ca:Mg was not associated with either outcomes, regardless of depression status. Conclusions Mg intake was associated with both sleep outcomes in this longitudinal analysis. Randomized controlled trials with objective measures of sleep are warranted to establish the potential causal inference.

Comparison of vestibular evoked myogenic potentials elicited by click and short duration tone burst stimuli

2010 ◽  
Vol 125 (4) ◽  
pp. 343-347 ◽  
Author(s):  
K Kumar ◽  
S Kumar Sinha ◽  
A Kumar Bharti ◽  
A Barman
Keyword(s):  
Short Duration ◽  
Clinical Assessment ◽  
Low Frequency ◽  
Tone Burst ◽  
Normal Hearing ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
Acoustic Stimuli ◽  
Myogenic Potential ◽  
Electrical Impulses

AbstractIntroduction:Vestibular evoked myogenic potentials are short latency electrical impulses that are produced in response to higher level acoustic stimuli. They are used clinically to diagnose sacculocollic pathway dysfunction.Aim:This study aimed to compare the vestibular evoked myogenic potential responses elicited by click stimuli and short duration tone burst stimuli, in normal hearing individuals.Method:Seventeen subjects participated. In all subjects, we assessed vestibular evoked myogenic potentials elicited by click and short duration tone burst stimuli.Results and conclusion:The latency of the vestibular evoked myogenic potential responses (i.e. the p13 and n23 peaks) was longer for tone burst stimuli compared with click stimuli. The amplitude of the p13–n23 waveform was greater for tone burst stimuli than click stimuli. Thus, the click stimulus may be preferable for clinical assessment and identification of abnormalities as this stimulus has less variability, while a low frequency tone burst stimulus may be preferable when assessing the presence or absence of vestibular evoked myogenic potential responses.

Determination of Positional Skin-Surface Pressures in Premature Infants

2004 ◽  
Vol 23 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Lenora Marcellus
Keyword(s):  
Premature Infants ◽  
Repeated Measures ◽  
Skin Surface ◽  
Repeated Measures Design ◽  
Pressure Distributions ◽  
Body Tissues ◽  
Starting Point ◽  
Postconceptional Age ◽  
Maximal Pressure ◽  
The Mean

Purpose: To describe the skin-surface pressure distributions and points of maximal pressure that are generated by healthy premature infants in the supine, prone, and right side–lying positions.Design: A descriptive, repeated-measures design.Sample: Four medically stable premature infants of 34 weeks postconceptional age. The mean weight was 2,180 gm, and the mean age was 24.5 days.Results: Similar regions of increased skin-surface pressures were identified for the four infants. Within areas of peak pressure, some sensor cells reached 28–32 millimeters of mercury, which is considered to be the critical compressive pressure for obstruction of nutritive flow to the underlying body tissues. These descriptive results may be a starting point for development of research studies to determine positioning strategies to optimize the skin integrity of premature infants while minimizing unnecessary handling.

Vestibular evoked myogenic potentials: review

2010 ◽  
Vol 124 (10) ◽  
pp. 1043-1050 ◽  
Author(s):  
R Mudduwa ◽  
N Kara ◽  
D Whelan ◽  
Anirvan Banerjee
Keyword(s):  
Vestibular Function ◽  
Extensive Study ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
Clinical Role ◽  
Myogenic Potential ◽  
Future Developments ◽  
Early Results ◽  
Clinical Conditions ◽  
Based Medicine

AbstractBackground:Disorders of balance often pose a diagnostic conundrum for clinicians, and a multitude of investigations have emerged over the years. Vestibular evoked myogenic potential testing is a diagnostic tool which can be used to assess vestibular function. Over recent years, extensive study has begun to establish a broader clinical role for vestibular evoked myogenic potential testing.Objectives:To provide an overview of vestibular evoked myogenic potential testing, and to present the evidence for its clinical application.Review type:Structured literature search according to evidence-based medicine guidelines, performed between November 2008 and April 2009. No restrictions were applied to the dates searched.Conclusion:The benefits of vestibular evoked myogenic potential testing have already been established as regards the diagnosis and monitoring of several clinical conditions. Researchers continue to delve deeper into potential new clinical applications, with early results suggesting promising future developments.

scholarly journals Vestibular evoked myogenic potential

2014 ◽  
Vol 67 (suppl. 1) ◽  
pp. 38-45
Author(s):  
Slobodanka Lemajic-Komazec ◽  
Zoran Komazec ◽  
Ljiljana Vlaski ◽  
Slobodan Savovic ◽  
Maja Buljcik-Cupic ◽  
...  
Keyword(s):  
Tone Burst ◽  
Acoustic Stimulation ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
Average Value ◽  
Myogenic Potential ◽  
The Difference ◽  
Interaural Differences ◽  
The Right ◽  
A Prospective Study

Introduction. Vestibular evoked myogenic potentials are neurophysiological method for examining of saccular function, the bottom of the vestibular nerve that in nervates the sacculus and central vestibular pathways. Those are inhibitory potentials of the sternocleido mastoid musclein response to ipsilateral acoustic stimulation of the sacculus. Parameters of vestibular evoked myogenic potential testing include threshold, latencies of p1 and n1 wave and interamplitude p13-n23, interaural difference of p13 and n23 latency and interaural amplitude difference ratio. The aim of this study was to compire parameters standardization of vestibular evoked myogenic potentials responses, latency p13 and n23 of waves, the amplitude of responses and interaural differences in the amplitude andto determinewhether there is a difference in values between the sexes. Material and methods. This research was meant to be a prospective study which included 30 normal audiovestibular volunteers of both sexes. The group consisted of 53.3% women and 46.7% men. The saccular function testing by vestibular evoked myogenic potentials was performed monoaurally using air-conductive 500 Hz tone burst auditory stimulation. Results. The average value of the p13 wave latency in healthy subjects of this study was 15.18 ms (?1.24) while the mean latency of n23 waves in the same subjects was 25.00 ms (?2.23). The average value of the amplitude of the p13-n23 waves was 80.28 (34. ?04) microvolts. Conclusion. The difference in the values of the basic parameters of vestibular evoked myogenic potential responses between men and women does not exist. No differences between the right and the left ear in the values of latency and amplitude were observed.

Effects of Stimulus and Recording Parameters on the Air Conduction Ocular Vestibular Evoked Myogenic Potential

2011 ◽  
Vol 22 (07) ◽  
pp. 469-480 ◽  
Author(s):  
Owen D. Murnane ◽  
Faith W. Akin ◽  
J. Kip Kelly ◽  
Stephanie Byrd
Keyword(s):  
Repeated Measures ◽  
Normative Data ◽  
Stimulus Frequency ◽  
Stimulus Level ◽  
Diagnostic Information ◽  
Vestibular Nerve ◽  
Vestibular Evoked Myogenic Potentials ◽  
Repeated Measures Design ◽  
Electrode Location ◽  
Air Conduction

Background: Vestibular evoked myogenic potentials (VEMPs) have been recorded from the sternocleidomastoid muscle (cervical VEMP or cVEMP) and more recently from the eye muscles (ocular VEMP or oVEMP) in response to air conduction and bone conduction stimuli. Both cVEMPs and oVEMPs are mediated by the otoliths and thereby provide diagnostic information that is complementary to videonystagmography and rotational chair tests. In contrast to the air conduction cVEMP, which originates from the saccule/inferior vestibular nerve, recent evidence suggests the possibility that the air conduction oVEMP may be mediated by the utricle/superior vestibular nerve. The oVEMP, therefore, may provide complementary diagnostic information relative to the cVEMP. There are relatively few studies, however, that have quantified the effects of stimulus and recording parameters on the air conduction oVEMP, and there is a paucity of normative data. Purpose: To evaluate the effects of several stimulus and recording parameters on the air conduction oVEMP and to establish normative data for clinical use. Research Design: A prospective repeated measures design was utilized. Study Sample: Forty-seven young adults with no history of neurologic disease, hearing loss, middle ear pathology, open or closed head injury, cervical injury, or audiovestibular disorder participated in the study. Data Collection and Analysis: The effects of stimulus frequency, stimulus level, gaze elevation, and recording electrode location on the amplitude and latency of the oVEMP for monaural air conduction stimuli were assessed using repeated measures analyses of variance in an initial group of 17 participants. The optimal stimulus and recording parameters obtained in the initial group were used subsequently to obtain oVEMPs from 30 additional participants. Results: The effects of stimulus frequency, stimulus level, gaze elevation, and electrode location on the response prevalence, amplitude, and latency of the oVEMP for monaural air conduction stimuli were significant. The maximum N1-P1 amplitude and response prevalence were obtained for contralateral oVEMPs using a 500 Hz tone burst presented at 125 dB peak SPL during upward gaze at an elevation of 30°. Conclusions: The optimal stimulus and recording parameters quantified in this study were used to establish normative data that may be useful for the clinical application of the air conduction oVEMP.

scholarly journals The Importance of Isopropyl Alcohol in Skin Preparation Solutions

2011 ◽  
Vol 32 (4) ◽  
pp. 405-406 ◽  
Author(s):  
Lin M. Riccio ◽  
Brian R. Swenson ◽  
Robert G. Sawyer
Keyword(s):  
Isopropyl Alcohol ◽  
Skin Preparation
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