scholarly journals Measurements of the local evoked potential from the cochlear nucleus in patients with an auditory brainstem implant and its implication to auditory perception and audio processor programming

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249535
Author(s):  
Lutz Gärtner ◽  
Thomas Lenarz ◽  
Andreas Büchner
Keyword(s):  
Cochlear Nucleus ◽  
Auditory Perception ◽  
False Positive Rate ◽  
Electrode Array ◽  
Compound Action Potential ◽  
Auditory Brainstem ◽  
Auditory Brainstem Implant ◽  
Evoked Compound Action Potential ◽  
Positive Rate ◽  
Fitting In

The measurement of the electrically evoked compound action potential (ECAP) in cochlear implant (CI) patients is widely used to provide evidence of a functioning electrode-nerve interface, to confirm proper location of the electrode array and to program the sound processor. In patients with an auditory brainstem implant (ABI), a likewise versatile measurement would be desirable. The ECAP measurement paradigm “Alternating Polarity” was utilized to record responses via the implanted ABI electrode array placed on the cochlear nucleus. Emphasizing on the different location of stimulation and recording, these responses are called local evoked potentials (LEP). LEP measurements were conducted during the clinical routine in 16 ABI patients (12 children and 4 adults), corresponding to 191 electrode contacts. A retrospective analysis of these data revealed, that LEP responses were observed in 64.9% of all measured electrode contacts. LEP responses predicted auditory perception with a sensitivity of 90.5%. False-positive rate was 33.7%. Objective LEP thresholds were highly significantly (p < 0.001) correlated both to behavioral thresholds (Pearson’s r = 0.697) and behavioral most comfortable levels (r = 0.840). Therefore, LEP measurements have the potential to support fitting in ABI patients.

Multichannel auditory brainstem implant: update on performance in 61 patients

2002 ◽  
Vol 96 (6) ◽  
pp. 1063-1071 ◽  
Author(s):  
Steven R. Otto ◽  
Derald E. Brackmann ◽  
William E. Hitselberger ◽  
Robert V. Shannon ◽  
Johannes Kuchta
Keyword(s):  
Cochlear Nucleus ◽  
Electrode Array ◽  
Neurofibromatosis Type ◽  
Auditory Brainstem ◽  
Surgical Removal ◽  
Content Type ◽  
Auditory Brainstem Implant ◽  
Vs Removal ◽  
Fine Print

Object. Neurofibromatosis Type 2 (NF2) has typically resulted in deafness after surgical removal of bilateral vestibular schwannomas (VSs). Cochlear implants are generally ineffective for this kind of deafness because of the loss of continuity in the auditory nerve after tumor removal. The first auditory brainstem implant (ABI) in such a patient was performed in 1979 at the House Ear Institute, and this individual continues to benefit from electrical stimulation of the cochlear nucleus complex. In 1992, an advanced multichannel ABI was developed and a series of patients with NF2 received this implant to study the safety and efficacy of the device. Methods. At the time of first- or second-side VS removal, patients received an eight-electrode array applied to the surface of the cochlear nucleus within the confines of the lateral recess of the fourth ventricle. The device was activated approximately 6 weeks after implantation, and patients were tested every 3 months for the 1st year after the initial stimulation, and annually thereafter. The protocol included a comprehensive battery of psychophysical and speech perception tests. Conclusions. The multichannel ABI proved to be effective and safe in providing useful auditory sensations in most patients with NF2. The ABI improved patients' ability to communicate compared with the lipreading-only condition, it allowed the detection and recognition of many environmental sounds, and in some cases it provided significant ability to understand speech by using just the sound from the ABI (with no lipreading cues). Its performance in most patients has continued to improve for up to 8 years after implantation.

scholarly journals New Protocol for Auditory Brainstem Implant Positioning

2021 ◽  
Vol 9 (5) ◽  
pp. 01-07
Author(s):  
Sheila Veronese ◽  
Marco Cambiaghi ◽  
Andrea Sbarbati
Keyword(s):  
Cochlear Nucleus ◽  
Electrode Array ◽  
Auditory Brainstem ◽  
New Method ◽  
Average Charge ◽  
Stimulation Protocol ◽  
Channel Interaction ◽  
Auditory Brainstem Implant ◽  
Implant Positioning ◽  
Saturation Effects

Background: Surgery for applying the auditory brainstem implant is an otoneurosurgery that requires careful intraoperative monitoring to optimize the placement of the electrode paddle. This study aimed to validate a new method capable of increasing the accuracy of electrode array placement, reducing channel interaction, electrical artefacts, and saturation effects, and providing the largest number of electrodes that can be activated with the lowest possible electric charge. Materials and methods: Thirty-six subjects aged between 1.42 and 69.92 years were tested during surgery for auditory brainstem implantation. We recorded auditory electrical responses of the brainstem using the implant supplier's suggested stimulation protocol and the new protocol. Results: Saturations effects and electric artefacts were noticed respectively in 81.85% and 53.25% of recordings using implant supplier's method, while in 70.34% and 24.75% of recordings using the new method, with a percentage variation of 11.51% and 28.50%. Considering the amount of charge required to activate the electrodes, with the implant supplier's method an average charge of 14 nC was needed, while with the new protocol an average charge of 8 nC was necessary. Conclusions: The new method improves the coupling between the auditory brainstem implant and the surface of the cochlear nucleus.

The Auditory Brainstem Implant

2019 ◽  
pp. 758-770
Author(s):  
Robert V. Shannon
Keyword(s):  
Surgical Technique ◽  
Cochlear Nucleus ◽  
Meta Analysis ◽  
Auditory Brainstem ◽  
Auditory Information ◽  
Speech Understanding ◽  
Auditory Neurons ◽  
Auditory Brainstem Implant ◽  
The Brain ◽  
Implanted Device

The auditory brainstem implant (ABI) is a surgically implanted device to electrically stimulate auditory neurons in the cochlear nucleus complex of the brainstem in humans to restore hearing sensations. The ABI is similar in function to a cochlear implant, but overall outcomes are poorer. However, recent applications of the ABI to new patient populations and improvements in surgical technique have led to significant improvements in outcomes. While the ABI provides hearing benefits to patients, the outcomes challenge our understanding of how the brain processes neural patterns of auditory information. The neural pattern of activation produced by an ABI is highly unnatural, yet some patients achieve high levels of speech understanding. Based on a meta-analysis of ABI surgeries and outcomes, a theory is proposed of a specialized sub-system of the cochlear nucleus that is critical for speech understanding.

Adult Auditory Brainstem Implant Outcomes and Three-Dimensional Electrode Array Position on Computed Tomography

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Dana Egra-Dagan ◽  
Isabeau van Beurden ◽  
Samuel R. Barber ◽  
Christine L. Carter ◽  
Mary E. Cunnane ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Electrode Array ◽  
Auditory Brainstem ◽  
Auditory Brainstem Implant ◽  
Array Position

Topographic anatomy of the cochlear nuclear region at the floor of the fourth ventricle in humans

1999 ◽  
Vol 91 (3) ◽  
pp. 466-476 ◽  
Author(s):  
Ralf Quester ◽  
Roland Schröder
Keyword(s):  
Surgical Approach ◽  
Cochlear Nucleus ◽  
Fourth Ventricle ◽  
Auditory Brainstem ◽  
Nuclear Surface ◽  
Content Type ◽  
Auditory Brainstem Implant ◽  
Ventral Cochlear Nucleus ◽  
Small Series ◽  
Fine Print

Object. The development of appropriate methods to stimulate the dorsal and ventral cochlear nucleus by means of an auditory brainstem implant in patients with acquired bilateral anacusis requires a detailed topoanatomical knowledge both of the location and extension of the nuclear surface in the fourth ventricle and lateral recess and of its variability. The goal of this study was to provide that information. Anatomically, it is possible to use a midline surgical approach to the fourth ventricle rather than the translabyrinthine and suboccipital routes of access used hitherto. This is especially useful if severe scarring, which occurs as a result of tumor removal in the cerebellopontine angle, make the orientation and placement of an auditory brainstem implant via a lateral surgical approach difficult. There have been only a few studies, involving single cases and small series of patients, in which the focus was the exact extension of the cochlear nuclei, whose microsurgically relevant position in relation to the surface structures is not known in detail.Methods. Landmarks that are important for the placement of an auditory brainstem implant through the fourth ventricle were examined and measured in a large series of 28 formalin-fixed human brainstems. In all cases, these examinations were supplemented by addition of a histological section series. For the first time values of unfixed fresh brainstem tissue were determined. Anatomical features are discussed with regard to their possible neurosurgical relevance, taking into account inter- and intraindividual variability.Conclusions. The midline approach would provide an opportunity to stimulate the whole area of the dorsal as well as the ventral cochlear nucleus with an auditory brainstem implant.

Children with Auditory Brainstem Implant: How Do They Perform in Motor and Language Skills?

2021 ◽  
pp. 1-9
Author(s):  
Gorkem Ertugrul ◽  
Filiz Aslan ◽  
Gonca Sennaroglu ◽  
Levent Sennaroglu
Keyword(s):  
Speech Perception ◽  
Auditory Perception ◽  
Language Skills ◽  
Expressive Language ◽  
Auditory Brainstem ◽  
Receptive Language ◽  
Manual Dexterity ◽  
Language Performance ◽  
Balance Beam ◽  
Auditory Brainstem Implant

<b><i>Background:</i></b> Young children are able to explore new objects and practice language through the acquisition of motor skills that lead to their overall development. Congenital hearing loss and total vestibular loss may contribute to the delay in speech and motor skill development. <b><i>Objectives:</i></b> To investigate the relationship between motor development performance, speech perception, and language performance in children with auditory brainstem implant (ABI). <b><i>Method:</i></b> Ten children, aged 4–17 years (mean age 9.76 ± 4.03), fitted with unilateral ABI for at least 2 years due to the presence of labyrinthine aplasia and rudimentary otocyst at least 1 side were included in the study. Several standardized tests, such as Bruininks-Oseretsky Motor Proficiency Test-2 (BOT-2), Children’s Auditory Perception Test Battery, Meaningful Auditory Integration Scale (MAIS), and Test of Early Language Development-3, were performed to evaluate their skills of fine motor control, balance, manual dexterity, language, and auditory perception. <b><i>Results:</i></b> A significant correlation was established between the BOT-2 manual dexterity and MAIS scores (<i>r</i> = 0.827, <i>p</i> &#x3c; 0.05) and between the manual dexterity and language skills (for expressive language, <i>r</i> = 0.762, <i>p</i> &#x3c; 0.05; for receptive language, <i>r</i> = 0.650, <i>p</i> &#x3c; 0.05). Some of the BOT-2 balance tasks, such as standing on 1 leg on a line with eyes closed, standing on 1 leg on a balance beam with eyes open, standing heel-to-toe on a balance beam, and walking forward heel-to-toe on a line, showed a strong correlation with their receptive and expressive language performance (<i>p</i> &#x3c; 0.05). <b><i>Conclusion:</i></b> The current study has indicated that significantly poor manual and balance performances are associated with poor speech perception and language skills in children with ABI. The authors recommend performing a vestibular assessment before and after ABI surgery and the use of a holistic rehabilitation approach, including auditory and vestibular rehabilitation, to support development of the children with ABI.

scholarly journals Correlation of Electrically Evoked Compound Action Potential Amplitude Growth Function Slope and Anamnestic Parameters in Cochlear Implant Patients—Identification of Predictors for the Neuronal Health Status

Life ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 203
Author(s):  
Lutz Gärtner ◽  
Katharina Klötzer ◽  
Thomas Lenarz ◽  
Verena Scheper
Keyword(s):  
Hearing Loss ◽  
Health Status ◽  
Cochlear Implantation ◽  
Electrode Array ◽  
Compound Action Potential ◽  
Growth Function ◽  
Evoked Compound Action Potential ◽  
The Mean ◽  
Amplitude Growth ◽  
Compound Action

Cochlear implants (CI) are the treatment of choice in profoundly deaf patients. Measuring the electrically evoked compound action potential (ECAP) has become an important tool for verifying the function of the spiral ganglion neurons (SGN), which are the target cells of the CI stimulation. ECAP measurement is only possible after electrode insertion. No information about the neuronal health status is available before cochlear implantation. We investigated possible correlations between the ECAP amplitude growth function (AGF) slope and anamnestic parameters to identify possible predictors for SGN health status and therefore for CI outcome. The study included patients being implanted with various electrode array lengths. Correlation analysis was performed for the mean AGF slope of the whole array, for separate electrodes as well as for grouped electrodes of the apical, medial, and basal region, with duration of deafness, age at implantation, residual hearing (grouped for electrode length), and etiology. The mean ECAP AGF slopes decreased from apical to basal. They were not correlated to the length of the electrode array or any etiology. For the mean of the full array or when grouped for the apical, middle, and basal part, the ECAP AGF slope was negatively correlated to the duration of hearing loss and the age at implantation. Since a significant negative correlation of the ECAP AGF slope and age at cochlear implantation and duration of deafness was observed, this study supports the statement that early implantation of a CI is recommended for sensorineural hearing loss. Additional factors such as the cochlear coverage and insertion angle influence the ECAP AGF slope and performance of the patient and should be included in future multifactorial analysis to study predictive parameters for the CI outcome.

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