Verification of a new test of endolymphatic hydrops

1989 ◽  
Vol 103 (12) ◽  
pp. 1136-1139 ◽  
Author(s):  
A. R. D. Thornton ◽  
G. Farrell ◽  
A. J. Phillips ◽  
N. P. Haacke ◽  
S. Rhys-Williams
Keyword(s):  
Blood Sample ◽  
Wave Velocity ◽  
Basilar Membrane ◽  
Endolymphatic Hydrops ◽  
Plasma Osmolality ◽  
Prognostic Indicator ◽  
Auditory Brainstem ◽  
Travelling Wave ◽  
Lemon Juice ◽  
Brainstem Response

AbstractA new objective test of endolymphatic hydrops has been described previously. The test uses auditory brainstem response (ABR) techniques to estimate the basilar membrane travelling wave velocity (TWV). The underlying hypothesis is that raised pressure in the scala media will lead to an increase in the stiffness of the basilar membrane and that this will give rise to a travelling wave velocity that is greater than normal.It was considered that verification of the technique could be obtained by carrying out the new test before and during a glycerol dehydration procedure. Patients who required this procedure for verification of the diagnosis or as a prognostic indicator for sacculotomy, underwent the following tests. Prior to dehydration an audiogram, the ABR TWV test and a blood sample (for plasma osmolality) were taken. The patient was then given the appropriate amount of glycerol mixed with lemon juice and laid on a bed in a test room. The audiogram and a blood sample were repeated every hour and the ABR TWV test was repeatedly carried out every twenty minutes between the other tests.Six of these procedures have been carried out. In five of them the 0.5 and 1kHz average threshold improved by at least 10dB and in all those cases the ABR TWV test showed an abnormal pre-dehydration result which moved towards the normal value following dehydration. One patient gave ABR TWV results that were within normal limits before and during the procedure and gave an audiometric change of only 5dB.These data indicate that the ABR TWV test does detect endolymphatic hydrops. The additional hardware to carry out this test has been constructed and parallel clinical trials at IHR Southampton, Addenbrooke's Hospital, Cambridge, and Queen's Medical Centre, Nottingham, are in hand.

Analysis of Click and Swept-Tone Auditory Brainstem Response Results for Moderate and Severe Sensorineural Hearing Loss

2020 ◽  
Vol 25 (6) ◽  
pp. 336-344
Author(s):  
Jingqian Tan ◽  
Jia Luo ◽  
Xin Wang ◽  
Yanbing Jiang ◽  
Xiangli Zeng ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Auditory Brainstem Response ◽  
Basilar Membrane ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Control Group ◽  
Hearing Sensitivity ◽  
Brainstem Response ◽  
Frequency Components

<b><i>Introduction:</i></b> Auditory brainstem response (ABR) is one of the commonly used methods in clinical settings to evaluate the hearing sensitivity and auditory function. The current ABR measurement usually adopts click sound as the stimuli. However, there may be partial ABR amplitude attenuation due to the delay characteristics of the cochlear traveling wave along the basilar membrane. To solve that problem, a swept-tone method was proposed, in which the show-up time of different frequency components was adjusted to compensate the delay characteristics of the cochlear basilar membrane; therefore, different ABR subcomponents of different frequencies were synchronized. <b><i>Methods:</i></b> The normal hearing group, moderate sensorineural hearing loss group, and severe sensorineural hearing loss group underwent click ABR and swept-tone ABR with different stimulus intensities. The latencies and amplitudes of waves I, III, and V in 2 detections were recorded. <b><i>Results:</i></b> It was found that the latency of each of the recorded I, III, and V waves detected by swept-tone ABR was shorter than that by click ABR in both the control group and experimental groups. In addition, the amplitude of each of the recorded I, III, and V waves, except V waves under 60 dB nHL in the moderate sensorineural hearing loss group, detected by swept-tone ABR was larger than that by click ABR. The results also showed that the swept-tone ABR could measure the visible V waves at lower stimulus levels in the severe sensorineural hearing loss group. <b><i>Conclusion:</i></b> Swept-tone improves the ABR waveforms and helps to obtain more accurate threshold to some extent. Therefore, the proposed swept-tone ABR may provide a new solution for better morphology of ABR waveform, which can help to make more accurate diagnosis about the hearing functionality in the clinic.

scholarly journals Similarities and Differences Between Vestibular and Cochlear Systems – A Review of Clinical and Physiological Evidence

2021 ◽  
Vol 15 ◽  
Author(s):  
Ian S. Curthoys ◽  
John Wally Grant ◽  
Christopher J. Pastras ◽  
Laura Fröhlich ◽  
Daniel J. Brown
Keyword(s):  
Structural Changes ◽  
Endolymphatic Hydrops ◽  
Vestibular Function ◽  
Auditory Brainstem ◽  
Type I ◽  
Vestibular Evoked Myogenic Potential ◽  
Unique Type ◽  
Myogenic Potential ◽  
Brainstem Response ◽  
Similarities And Differences

The evoked response to repeated brief stimuli, such as clicks or short tone bursts, is used for clinical evaluation of the function of both the auditory and vestibular systems. One auditory response is a neural potential — the Auditory Brainstem Response (ABR) — recorded by surface electrodes on the head. The clinical analogue for testing the otolithic response to abrupt sounds and vibration is the myogenic potential recorded from tensed muscles — the vestibular evoked myogenic potential (VEMP). VEMPs have provided clinicians with a long sought-after tool — a simple, clinically realistic indicator of the function of each of the 4 otolithic sensory regions. We review the basic neural evidence for VEMPs and discuss the similarities and differences between otolithic and cochlear receptors and afferents. VEMPs are probably initiated by sound or vibration selectively activating afferent neurons with irregular resting discharge originating from the unique type I receptors at a specialized region of the otolithic maculae (the striola). We review how changes in VEMP responses indicate the functional state of peripheral vestibular function and the likely transduction mechanisms allowing otolithic receptors and afferents to trigger such very short latency responses. In section “ELECTROPHYSIOLOGY” we show how cochlear and vestibular receptors and afferents have many similar electrophysiological characteristics [e.g., both generate microphonics, summating potentials, and compound action potentials (the vestibular evoked potential, VsEP)]. Recent electrophysiological evidence shows that the hydrodynamic changes in the labyrinth caused by increased fluid volume (endolymphatic hydrops), change the responses of utricular receptors and afferents in a way which mimics the changes in vestibular function attributed to endolymphatic hydrops in human patients. In section “MECHANICS OF OTOLITHS IN VEMPS TESTING” we show how the major VEMP results (latency and frequency response) follow from modeling the physical characteristics of the macula (dimensions, stiffness etc.). In particular, the structure and mechanical operation of the utricular macula explains the very fast response of the type I receptors and irregular afferents which is the very basis of VEMPs and these structural changes of the macula in Menière’s Disease (MD) predict the upward shift of VEMP tuning in these patients.

scholarly journals Auditory evoked potentials as yardstick for tinnitus

2021 ◽  
Vol 7 (5) ◽  
pp. 789
Author(s):  
Shrutinath Banerjee ◽  
Nilanjan Paul ◽  
Indranil Chatterjee ◽  
Ishita Das ◽  
Rima Das ◽  
...  
Keyword(s):  
Auditory Evoked Potentials ◽  
Otoacoustic Emission ◽  
Prognostic Indicator ◽  
Auditory Brainstem ◽  
Tinnitus Retraining Therapy ◽  
Middle Latency Response ◽  
Retraining Therapy ◽  
Brainstem Response ◽  
Latency Response ◽  
Middle Latency

<p class="abstract"><strong>Background:</strong> Aiming to evaluate the recent theoretical postulates on tinnitus underscoring the role of thalamocortical neural tracts, the present study: explores middle latency response (MLR) as a possible physiological measure of tinnitus: thus investigates the predicted exaggeration of P<sub>a</sub>-N<sub>a</sub>, N<sub>a</sub>-P<sub>b</sub> interpeak amplitudes in tinnitus patients and; explores middle latency response (MLR) as a prognostic indicator of tinnitus retraining therapy (TRT), thus evaluates possible decrease in P<sub>a</sub>-N<sub>a</sub> and N<sub>a</sub>-P<sub>b</sub> amplitude after 2 weeks exposure to tinnitus retraining therapy.</p><p class="abstract"><strong>Methods:</strong> An experimental group was constructed by randomly assigning 30 patients with mean age 38.5 years and complaining of debilitating tinnitus but with normal hearing for the study. MLR was administered on patients with normal auditory brainstem response (ABR) and otoacoustic emission (OAE) both pre- and post-tinnitus retraining therapy.  </p><p class="abstract"><strong>Results:</strong> Results demonstrated no significant effect on P<sub>a</sub>, N<sub>a</sub> and N<sub>b</sub> absolute and interpeak latencies. However, significantly exaggerated P<sub>a</sub>-N<sub>a</sub> and N<sub>a</sub>-P<sub>b</sub> interpeak amplitudes between experimental and control groups as well as pre and post therapeutic groups were found.</p><p class="abstract"><strong>Conclusions:</strong> This proves that MLR may adequately reflect thalamocortical hyperactivity in cases with distressing tinnitus and demonstrable improvement post TRT warrants the use of MLR as its prognostic indicator.</p>

scholarly journals Audiovestibular Function Deficits in Vestibular Schwannoma

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Constantin von Kirschbaum ◽  
Robert Gürkov
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Otoacoustic Emissions ◽  
Endolymphatic Hydrops ◽  
Tumour Size ◽  
Auditory Brainstem ◽  
Vestibular Evoked Myogenic Potentials ◽  
Prognostic Information ◽  
Brainstem Response ◽  
Benign Tumours

Introduction. Vestibular schwannomas (VS) are benign tumours of the vestibular nerve and can lead to hearing loss, tinnitus, vertigo, facial palsy, and brainstem compression. Audiovestibular diagnostic tests are essential for detection and treatment planning.Methods. Medline was used to perform a systematic literature review with regard to how audiovestibular test parameters correlate with symptoms, tumour size, and tumour location.Results. The auditory brainstem response can be used to diagnose retrocochlear lesions caused by VS. Since hearing loss correlates poorly with tumour size, a retrocochlear lesion is probably not the only cause for hearing loss. Also cochlear mechanisms seem to play a role. This can be revealed by abnormal otoacoustic emissions, despite normal ABR and new MRI techniques which have demonstrated endolymphatic hydrops of the inner ear. Caloric and head impulse tests show frequency specific dynamics and vestibular evoked myogenic potentials may help to identify the location of the tumour regarding the involved nerve parts.Conclusion. In order to preserve audiovestibular function in VS, it is important to stop the growth of the tumour and to avoid degenerative changes in the inner ear. A detailed neurotological workup helps to diagnose VS of all sizes and can also provide useful prognostic information.

Hit and False-Alarm Rates of Selected ABR Indices in Differentiating Cochlear Disorders From Acoustic Tumors

1996 ◽  
Vol 5 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Frank E. Musiek ◽  
Cynthia A. McCormick ◽  
Raymond M. Hurley
Keyword(s):  
False Alarm ◽  
Amplitude Ratio ◽  
High Specificity ◽  
Auditory Brainstem ◽  
Latency Difference ◽  
Cochlear Pathology ◽  
Brainstem Response ◽  
Absolute Latency ◽  
Two Indices ◽  
Low Sensitivity

We performed a retrospective study of 26 patients with acoustic tumors and 26 patients with otologically diagnosed cochlear pathology to determine the sensitivity (hit rate), specificity (false-alarm rate), and efficiency of six auditory brainstem response indices. In addition, a utility value was determined for each of these six indices. The I–V interwave interval, the interaural latency difference, and the absolute latency of wave V provided the highest hit rates, the best A’ values and good utility. The V/I amplitude ratio index provided high specificity but low sensitivity scores. In regard to sensitivity and specificity, using the combination of two indices provided little overall improvement over the best one-index measures.

The Effect of Kalman-Weighted Averaging and Artifact Rejection on Residual Noise During Auditory Brainstem Response Testing

2019 ◽  
Vol 28 (1) ◽  
pp. 114-124
Author(s):  
Linda W. Norrix ◽  
Julie Thein ◽  
David Velenovsky
Keyword(s):  
Repeated Measures ◽  
Auditory Brainstem ◽  
Weighted Averaging ◽  
Auditory Brainstem Responses ◽  
Residual Noise ◽  
Electrophysiological Recordings ◽  
Artifact Rejection ◽  
Brainstem Response ◽  
Active Motor ◽  
Averaging Time

Purpose Low residual noise (RN) levels are critically important when obtaining electrophysiological recordings of threshold auditory brainstem responses. In this study, we examine the effectiveness and efficiency of Kalman-weighted averaging (KWA) implemented on the Vivosonic Integrity System and artifact rejection (AR) implemented on the Intelligent Hearing Systems SmartEP system for obtaining low RN levels. Method Sixteen adults participated. Electrophysiological measures were obtained using simultaneous recordings by the Vivosonic and Intelligent Hearing Systems for subjects in 2 relaxed conditions and 4 active motor conditions. Three averaging times were used for the relaxed states (1, 1.5, and 3 min) and for the active states (1.5, 3, and 6 min). Repeated-measures analyses of variance were used to examine RN levels as a function of noise reduction strategy (i.e., KWA, AR) and averaging time. Results Lower RN levels were obtained using KWA than AR in both the relaxed and active motor states. Thus, KWA was more effective than was AR under the conditions examined in this study. Using KWA, approximately 3 min of averaging was needed in the relaxed condition to obtain an average RN level of 0.025 μV. In contrast, in the active motor conditions, approximately 6 min of averaging was required using KWA. Mean RN levels of 0.025 μV were not attained using AR. Conclusions When patients are not physiologically quiet, low RN levels are more likely to be obtained and more efficiently obtained using KWA than AR. However, even when using KWA, in active motor states, 6 min of averaging or more may be required to obtain threshold responses. Averaging time needed and whether a low RN level can be attained will depend on the level of motor activity exhibited by the patient.

Comparisons of Auditory Brainstem Responses Between a Laboratory and Simulated Home Environment

2020 ◽  
Vol 63 (11) ◽  
pp. 3877-3892
Author(s):  
Ashley Parker ◽  
Candace Slack ◽  
Erika Skoe
Keyword(s):  
Home Environment ◽  
Signal To Noise Ratio ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Single Family ◽  
Adult Participants ◽  
Simulated Home Environment ◽  
Brainstem Response ◽  
Research Populations ◽  
Response Consistency

Purpose Miniaturization of digital technologies has created new opportunities for remote health care and neuroscientific fieldwork. The current study assesses comparisons between in-home auditory brainstem response (ABR) recordings and recordings obtained in a traditional lab setting. Method Click-evoked and speech-evoked ABRs were recorded in 12 normal-hearing, young adult participants over three test sessions in (a) a shielded sound booth within a research lab, (b) a simulated home environment, and (c) the research lab once more. The same single-family house was used for all home testing. Results Analyses of ABR latencies, a common clinical metric, showed high repeatability between the home and lab environments across both the click-evoked and speech-evoked ABRs. Like ABR latencies, response consistency and signal-to-noise ratio (SNR) were robust both in the lab and in the home and did not show significant differences between locations, although variability between the home and lab was higher than latencies, with two participants influencing this lower repeatability between locations. Response consistency and SNR also patterned together, with a trend for higher SNRs to pair with more consistent responses in both the home and lab environments. Conclusions Our findings demonstrate the feasibility of obtaining high-quality ABR recordings within a simulated home environment that closely approximate those recorded in a more traditional recording environment. This line of work may open doors to greater accessibility to underserved clinical and research populations.

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