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Magnitude Estimates Of Angular Motion: Perception Of Speed And Spatial Orientation Across Visual And Vestibular Modalities, Erin Hernon
Dissertations, 2020-current
Both the vestibular system and optokinetic system generate conjugate eye movements in response to either movement of the head or movement of the visual surround. Both systems help to maintain gaze stability. While the VOR is most sensitive to input frequencies above .2 Hz, the optokinetic system helps maintain gaze stability at lower frequencies. Previous research on perceptual thresholds across the two sensory modalities shows that there are frequency-dependent differences between vestibular and visual perception. The purpose of this study is to extend previous vestibular psychophysics work by 1) comparing magnitude estimates from vestibular stimulation to visual stimulation across multiple …
Role Of Emg Monitoring On Cvemp Testing In Preschool Age Children, Brenna Murray
Role Of Emg Monitoring On Cvemp Testing In Preschool Age Children, Brenna Murray
Dissertations, 2020-current
While cervical vestibular evoked myogenic potential (cVEMP) testing has largely been studied and practiced on the adult population, less is known about the best practices for performing cVEMPs on a pediatric population, especially in young children under the age of 5 years. Further, very young children (i.e., 2-3 years) often prefer to sit with their caregiver during the testing, yet there is very little data on how much electromyographic (EMG) activity a child generates if in a seated position as opposed to a supine position. The purpose of this study was to assess the role of EMG on cVEMP recordings …
The Relationship Between The Vestibular Ocular Reflex And Perception In Young Healthy Adults, Susanne Nelson
The Relationship Between The Vestibular Ocular Reflex And Perception In Young Healthy Adults, Susanne Nelson
Dissertations, 2020-current
Vestibular impairments are often identified through measures of vestibular reflexes such as the vestibulo-ocular reflex (VOR). However, in clinical practice measures of the VOR do not always correlate with the patient’s reported symptoms. In contrast to physiologic measures like the VOR, psychophysical methods can be used to assess a person’s perception of movement. Previous psychophysics research shows that perceptual thresholds of angular motion do not correlate with VOR measures, but this has not been assessed at suprathreshold levels. The purpose of this study was to assess whether vestibular reflexive responses (i.e., VOR) were correlated to the patient’s perception of movement …
Amplitude-Modulated Cvemp (Amcvemps) Versus Transient Cvemp Response Properties: Possible Implications, Andrew Thorne
Amplitude-Modulated Cvemp (Amcvemps) Versus Transient Cvemp Response Properties: Possible Implications, Andrew Thorne
Dissertations, 2020-current
Cervical vestibular evoked myogenic potentials (cVEMPs) elicited by steady-state amplitude-modulated (AM) tones yield different information than conventional cVEMPs elicited by transient tonebursts, such as signal-to-noise ratio (SNR) and phase coherence (PC). This study systematically examined the effects of tonic EMG activation on AMcVEMP response properties versus conventional transient cVEMPs. Thirty five young, healthy adults (ages 19–23) with normal audiograms and no known vestibular lesions participated in this study. AMcVEMPs were elicited with bone-conducted tones with a carrier frequency of 500 Hz and an amplitude modulation frequency of 37 Hz, and transient cVEMPs were elicited by 4-0-4 Blackman-gated 500 Hz tonebursts …
Temporal Modulation Transfer Functions Of Amplitude-Modulated Cervical Vestibular Evoked Myogenic Potentials In Young Adults, Kerri Lawlor
Temporal Modulation Transfer Functions Of Amplitude-Modulated Cervical Vestibular Evoked Myogenic Potentials In Young Adults, Kerri Lawlor
Dissertations, 2020-current
Cervical vestibular evoked myogenic potentials (cVEMPs) are widely used to evaluate saccular function in clinical and research applications. Typically, transient tonebursts are used to elicit cVEMPs. In this study, we used bone-conducted amplitude-modulated (AM) tones to elicit AMcVEMPs. This new approach allows the examination of phase-locked vestibular responses across a range of modulation frequencies. Currently, cVEMP temporal modulation transfer functions (TMTFs) are not well defined. The purposes of the present study were 1) to characterize the AMcVEMP TMTF in young, healthy individuals, 2) to compare AMcVEMP TMTFs across different analysis approaches, and 3) to determine the upper frequency limit of …
Objective Detection Of Vestibular Evoked Myogenic Potentials, Daniel J. Romero
Objective Detection Of Vestibular Evoked Myogenic Potentials, Daniel J. Romero
Dissertations, 2020-current
Cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs, respectfully) are considered objective tests of vestibular function measured using surface electromyography (EMG). In addition, VEMPs are visually detected by an examiner, often requiring a high level of stimulation to the ear to easily visualize a waveform plotted across time. However, a high level of stimulation, like those used during routine VEMP testing, is problematic since it has been shown to be unsafe in children when compared to adults. Visual interpretation can also vary between examiners in cases of reduced vestibular function or when the level of required muscle contraction …
Dual Task Study Of Cognitive And Postural Interference: Development Of A Methodology For Use In Vestibular Disorders, Valerie Beacham
Dual Task Study Of Cognitive And Postural Interference: Development Of A Methodology For Use In Vestibular Disorders, Valerie Beacham
Dissertations, 2020-current
For patients with vestibular impairments, postural stability alone can be demanding but is more taxing when an individual’s attention is focused on both maintaining balance and a secondary/cognitive task simultaneously. Thus, dual task paradigms where balance must be maintained while performing postural and cognitive tasks concurrently provides an assessment on one’s attentional resources available for balance. Previous studies show varying levels of dual task effects in patients with vestibular loss with little consistency between studies regarding choice of balance and cognitive tasks. The purpose of this study was to assess the feasibility of a dual task paradigm using portable instrumentation …
Induction Of Nocebo Effects By Verbal Suggestions During The Caloric Test, Abbey Weist
Induction Of Nocebo Effects By Verbal Suggestions During The Caloric Test, Abbey Weist
Dissertations, 2020-current
The caloric test is the most frequently performed vestibular diagnostic test and is considered the “gold-standard” for the assessment of the peripheral vestibular system. Using a warm or cool stimulus, the caloric test alters the temperature gradient in the vestibular system resulting in nausea and dizziness. The nocebo effect is a phenomenon that can occur when negative expectations result in negative effects. No study has examined whether expectations of nausea and dizziness during the caloric test enhance the experience of unwanted symptoms. The purpose of this investigation was to determine whether a nocebo response can be elicited during the caloric …
Cervical Vestibular-Evoked Myogenic Potentials (Cvemps): "Differentiation Of Inter-Neck Emg Symmetry Between Children And Adults", Ellen Jones
Senior Honors Projects, 2010-2019
A cervical Vestibular-Evoked Myogenic Potential (cVEMP) is one of the few objective vestibular diagnostic tests available for pediatric populations. This test evaluates the functionality of the saccule end organ through an inhibitory reflex on the sternocleidomastoid (SCM) muscle that inhibits the level of electromyographic (EMG) activity (Wiener-Vacher, 2013). Because the saccule response is measured as an inhibition of EMG in the SCM, it is imperative that the SCM have a tonic contraction prior to eliciting the response and that the contraction of the SCM is equal on the right and left sides. It is generally accepted that young, healthy adults …
The Feasibility Of Standardized Cognitive Assessments For Vestibular Patients, Brynn Morales
The Feasibility Of Standardized Cognitive Assessments For Vestibular Patients, Brynn Morales
Senior Honors Projects, 2010-2019
Vestibular dysfunction, or impairments in the inner ear and/or brain structures that process sensory information and help control balance, has a high correlation with cognitive deficits, or problems with mental processes. This relationship negatively affects daily activities and quality of life in persons that live with vestibular dysfunction. Though there is sufficient research proving the relationship, few studies have applied that information in ways to better help the population with vestibular dysfunction. The purpose of this study was to assess the feasibility of a cognitive assessment battery (a set of correlated assessments delivered in one session) tailored to measuring performance …
Does Emg Monitoring In A Cvemp Matter?, Kimberly Fleck
Does Emg Monitoring In A Cvemp Matter?, Kimberly Fleck
Senior Honors Projects, 2010-2019
To determine if EMG monitoring or the use of amplitude normalization would significantly reduce the amplitude variability and amplitude asymmetry of the cVEMP in children ages 3 and under, we first needed to create a control group with young, healthy adults to compare the pediatric group to. We also wanted to replicate earlier studies that showed EMG monitoring and amplitude normalization does not have an impact on the VEMP in young, healthy adults. We tested two different positions, sitting and supine. Supine is the optimal position to generate EMG, but we wanted to have control data in case the pediatric …