scholarly journals PromBERA: A preoperative eABR: An update

2018 ◽  
Vol 4 (1) ◽  
pp. 563-565 ◽  
Author(s):  
Daniel Polterauer ◽  
Maike Neuling ◽  
Joachim Müller ◽  
John-Martin Hempel ◽  
Giacomo Mandruzzato ◽  
...  

AbstractPrior to cochlear implantation, audiological tests are performed to determine candidacy in subjects with a hearing loss. This is usually done by measuring the acoustic auditory brainstem response (ABR). Unfortunately, for some subjects, a reproducible ABR recording cannot be obtained, even at high acoustic levels. Having a healthy stimulating auditory nerve is required for cochlear implantation in order to benefit from the electrical pulses that are generated by the implant and to improve speech comprehension. In some subjects, this prerequisite cannot be measured using routine audiological tests. In this study, the feasibility of recording electrically evoked auditory brainstem responses (eABR) using a stimulating transtympanic electrode, placed on the round window niche, together with MED-EL clinical system is investigated. The results show that it is possible to record reproducible eABR measurements using PromBERA. The response was also confirmed with intraoperative eABR measurements that were stimulated using the implanted CI electrode array. Similarities between the intraoperative measurements and the preoperative recorded waveforms were observed. In summary, the integrity and excitability of the auditory nerve can be objectively measured using the PromBERA in subjects where standard clinical testing procedures are unable to provide the information required.


Author(s):  
Eriko Aiba ◽  
◽  
Koji Kazai ◽  
Takayuki Shimotomai ◽  
Toshie Matsui ◽  
...  

Synchrony judgment is one of the most important abilities for musicians. Only a few milliseconds of onset asynchrony result in a significant difference in musical expression. Using behavioural responses and Auditory Brainstem Responses (ABR), this study investigates whether synchrony judgment accuracy improves with training and, if so, whether physiological responses are also changed through training. Psychoacoustic experiments showed that accuracy of synchrony judgment of pianists was higher than that of non-pianists, implying that pianists’ ability to perceive tones increased through training. ABRmeasurements also showed differences between pianists and non-pianists. However, cochlear delay, an asymmetric aspect of temporal processing in the human auditory system, did not change with training. It is possible that training improved ability related to temporal tone perception and that training may increase synchrony in auditory nerve firing.



2017 ◽  
Vol 131 (3) ◽  
pp. 245-252
Author(s):  
H Gur ◽  
Y Alimoglu ◽  
U Duzenli ◽  
S Korkmaz ◽  
S Inan ◽  
...  

AbstractBackground:Electrode insertion during cochlear implantation causes cochlear damage and apoptosis. Insulin-like growth factor applied locally was investigated in 21 rats.Methods:In the sham group, an intracochlear dummy electrode was inserted through the round window. In the control group, after the same insertion procedure, saline-soaked porcine skin gelatine was placed on the round window. In the study group, insulin-like growth factor 1 soaked gelatine was placed on the round window. Auditory brainstem response thresholds were measured and histopathological examination was performed.Results:In the study group, at 2–4 kHz, one rat had deterioration, one showed improvement and the rest had stable thresholds 14 days after intervention. At 6 kHz, four rats showed improvement and the rest remained stable. At 8 kHz, four showed improvement, one had deterioration and two remained stable. In the other groups, hearing loss deteriorated in about half of the rats and remained stable in the rest. The mean post-operative 6 kHz threshold was significantly lower than that immediately after the intervention in the study group, contrary to the other groups. The study group had significantly better mean histopathological grading than the other groups.Conclusion:Local insulin-like growth factor 1 application may protect hearing after cochlear implantation.



2015 ◽  
Vol 35 (5) ◽  
pp. 1905-1923 ◽  
Author(s):  
Dan Bing ◽  
Sze Chim Lee ◽  
Dario Campanelli ◽  
Hao Xiong ◽  
Masahiro Matsumoto ◽  
...  

Background: Accumulating evidence suggests that tinnitus may occur despite normal auditory sensitivity, probably linked to partial degeneration of the cochlear nerve and damage of the inner hair cell (IHC) synapse. Damage to the IHC synapses and deafferentation may occur even after moderate noise exposure. For both salicylate- and noise-induced tinnitus, aberrant N-methyl-d-aspartate (NMDA) receptor activation and related auditory nerve excitation have been suggested as origin of cochlear tinnitus. Accordingly, NMDA receptor inhibition has been proposed as a pharmacologic approach for treatment of synaptopathic tinnitus. Methods: Round-window application of the NMDA receptor antagonist AM-101 (Esketamine hydrochloride gel; Auris Medical AG, Basel, Switzerland) was tested in an animal model of tinnitus induced by acute traumatic noise. The study included the quantification of IHC ribbon synapses as a correlate for deafferentation as well as the measurement of the auditory brainstem response (ABR) to close-threshold sensation level stimuli as an indication of sound-induced auditory nerve activity. Results: We have shown that AM-101 reduced the trauma-induced loss of IHC ribbons and counteracted the decline of ABR wave I amplitude generated in the cochlea/auditory nerve. Conclusion: Local round-window application of AM-101 may be a promising therapeutic intervention for the treatment of synaptopathic tinnitus.



2020 ◽  
Vol 134 (3) ◽  
pp. 219-221 ◽  
Author(s):  
A Jain ◽  
R Sharma ◽  
J C Passey ◽  
R Meher ◽  
R Bansal

AbstractBackgroundEndoscopes provide a magnified view of the middle ear and visualisation of hidden areas. Otoendoscopes facilitate excellent visualisation of the round window niche during cochlear implantation.ObjectiveTo compare microscopic and endoscopic visualisation of the round window membrane during cochlear implantation in 20 patients.MethodsTwenty patients who underwent cochlear implantation were included in the study. After maximum exposure of the round window, the accessibility of the round window membrane was graded according to the St Thomas Hospital classification, first by microscope and then by endoscope.ResultsWith the use of the endoscope, visualisation of the round window membrane improved in all the patients as compared to the microscope. The electrode array was inserted via a round window or extended round window approach in all but two cases; the latter cases required bony cochleostomy because of unfavourable anatomy.ConclusionThe main benefit of endoscope-assisted cochlear implantation is improved visibility of the round window region.



1984 ◽  
Vol 93 (4_suppl) ◽  
pp. 97-100 ◽  
Author(s):  
F. Blair Simmons ◽  
Tom Meyers ◽  
Hugh S. Lusted ◽  
Clough Shelton

Nerve survival estimates in totally deaf ears of cats and humans can be easily obtained by auditory brainstem responses to electrical stimulation at the round window. In humans, electrically induced auditory brainstem responses require considerably more current than concurrently observed perceptual thresholds and “maximum loudnesses,” and there is much variability from patient to patient. In cats, in which we also compared efficacy of stimulation sites, preliminary data analysis suggests that the scala tympani is clearly much more efficient than the round window, and the round window better than the promontory in ears with large populations of ganglion cells. In ears with no or nearly no ganglion cells, scala tympani and round window stimulations are about equal.



2011 ◽  
Vol 125 (7) ◽  
pp. 673-685 ◽  
Author(s):  
F-L Chi ◽  
M-Q Yang ◽  
Y-D Zhou ◽  
B Wang

AbstractObjective:To assess the therapeutic efficacy of dexamethasone administered topically to the round window niche, following acoustic trauma induced by intensive impulse noise, in guinea pigs.Methods:Adult, male, albino guinea pigs with a normal Preyer's reflex were exposed to 80 impulse noises (peak value 167 dB, duration 0.5 ms, interval 2 s). Dexamethasone (40 mg/ml) or saline was then topically applied to the round window niche. Each animal's auditory brainstem response was measured before and one day after exposure, and three weeks after topical treatment. Cochlear morphology was examined to assess hair cell loss and spiral ganglion cell damage. To assess oxidative activity, cochlear malondialdehyde and superoxide dismutase concentrations were determined three weeks post-treatment. Following topical application, the pharmacokinetic characteristics of dexamethasone in cochlear perilymph were analysed using high-performance liquid chromatography.Results:Animals receiving dexamethasone showed reduced noise-induced outer hair cell loss (three weeks post-treatment), and significant attenuation of noise-induced auditory brainstem response threshold shifts (one day post-exposure and three weeks post-treatment), compared with controls. There was no difference in spiral ganglion morphology. Animals receiving dexamethasone also showed a significantly lower malondialdehyde concentration and a higher superoxide dismutase concentration, post-exposure. Following topical application, the perilymph dexamethasone level peaked at 5330.522 µg/ml (15 minutes post-treatment), and was 299.797 µg/ml 360 minutes later.Conclusion:Topical application of dexamethasone to the round window niche has protective effects against intensive impulse noise induced trauma in the guinea pig cochlea. This drug can diffuse into the inner ear through the round window membrane and persist in the perilymph for a relatively long period. The mechanism of protection may involve an anti-oxidant effect.



Author(s):  
S N Dutt ◽  
A Kumar ◽  
A A Mittal ◽  
S Vadlamani ◽  
S K Gaur

Abstract Objective To evaluate the utility of pre-operative transtympanic electrically evoked auditory brainstem responses and post-operative neural response telemetry in auditory neuropathy spectrum disorder patients. Methods Four auditory neuropathy spectrum disorder patients who had undergone cochlear implantation and used it for more than one year were studied. All four patients underwent pre-operative transtympanic electrically evoked auditory brainstem response testing, intra-operative and post-operative (at 3, 6 and 12 months after switch-on) neural response telemetry, and out-patient cochlear implant electrically evoked auditory brainstem response testing (at 12 months). Results Patients with better waveforms on transtympanic electrically evoked auditory brainstem response testing showed superior performance after one year of implant use. Neural response telemetry and electrically evoked auditory brainstem response measures improved in all patients. Conclusion Inferences related to cochlear implantation outcomes can be based on the waveform of transtympanic electrically evoked auditory brainstem responses. Robust transtympanic electrically evoked auditory brainstem responses suggest better performance. Improvements in electrically evoked auditory brainstem responses and neural response telemetry over time indicate that electrical stimulation is favourable in auditory neuropathy spectrum disorder patients. These measures provide an objective way to monitor changes and progress in auditory pathways following cochlear implantation.



2019 ◽  
Author(s):  
Brad N. Buran ◽  
Sean Elkins ◽  
J. Beth Kempton ◽  
Edward V. Porsov ◽  
John V. Brigande ◽  
...  

AbstractAuditory brainstem responses (ABRs) require averaging responses to hundreds or thousands of repetitions of a stimulus (e.g., tone pip) to obtain a measurable evoked response at the scalp. Fast repetition rates lead to changes in ABR amplitude and latency due to adaptation. To minimize the effect of adaptation, stimulus rates are sometimes as low as 10 to 13.3 stimuli per second, requiring long acquisition times. The trade-off between reducing acquisition time and minimizing the effect of adaptation on ABR responses is an especially important consideration for studies of cochlear synaptopathy, which use the amplitude of short latency responses (wave 1) to assess auditory nerve survival. It has been proposed that adaptation during ABR acquisition can be reduced by interleaving tones at different frequencies, rather than testing each frequency serially. With careful ordering of frequencies and levels in the stimulus train, adaptation in the auditory nerve can be minimized, thereby permitting an increase in the rate at which tone bursts are presented. However, widespread adoption of this stimulus design has been hindered by lack of available software. Here, we develop and validate an interleaved stimulus design to optimize the rate of ABR measurement while minimizing adaptation. We implement this method in an open-source data acquisition software tool that permits either serial or interleaved ABR measurements. The open-source software library, psiexperiment, is compatible with widely-used ABR hardware. Consistent with previous studies, careful design of an interleaved stimulus train can reduce ABR acquisition time by more than half, with minimal effect on ABR thresholds and wave 1 latency, while improving measures of wave 1 amplitude.



2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
P. Bhatti ◽  
J. Van Beek-King ◽  
A. Sharpe ◽  
J. Crawford ◽  
S. Tridandapani ◽  
...  

We present an effective method for tailoring the flexibility of a commercial thin-film polymer electrode array for intracochlear electrical stimulation. Using a pneumatically driven dispensing system, an average232±64 μm (mean ± SD) thickness layer of silicone adhesive coating was applied to stiffen the underside of polyimide multisite arrays. Additional silicone was applied to the tip to protect neural tissue during insertion and along the array to improve surgical handling. Each array supported 20 platinum sites (180 μm dia., 250 μm pitch), spanning nearly 28 mm in length and 400 μm in width. We report an average intracochlear stimulating current threshold of170±93 μA to evoke an auditory brainstem response in 7 acutely deafened felines. A total of 10 arrays were each inserted through a round window approach into the cochlea’s basal turn of eight felines with one delamination occurring upon insertion (preliminary results of thein vivodata presented at the 48th Annual Meeting American Neurotology Society, Orlando, FL, April 2013, and reported in Van Beek-King 2014). Using microcomputed tomography imaging (50 μm resolution), distances ranging from 100 to 565 μm from the cochlea’s central modiolus were measured. Our method combines the utility of readily available commercial devices with a straightforward postprocessing step on the order of 24 hours.



2020 ◽  
Author(s):  
Melissa J Polonenko ◽  
Ross K Maddox

ABSTRACTThe auditory brainstem is important for processing speech, yet we have much to learn regarding the contributions of different subcortical structures. These deep neural generators respond quickly, making them difficult to study during dynamic, ongoing speech. Recently developed techniques have paved the way to use natural speech stimuli, but the auditory brainstem responses (ABRs) they provide are temporally broad and thus have ambiguous neural sources. Here we describe a new method that uses re-synthesized “peaky” speech stimuli and deconvolution analysis of EEG data to measure canonical ABRs to continuous naturalistic speech of male and female narrators. We show that in adults with normal hearing, peaky speech quickly yields robust ABRs that can be used to investigate speech processing at distinct subcortical structures from auditory nerve to rostral brainstem. We further demonstrate the versatility of peaky speech by simultaneously measuring bilateral and ear-specific responses across different frequency bands. Thus, the peaky speech method holds promise as a powerful tool for investigating speech processing and for clinical applications.



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