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Background Many patients with neurofibromatosis type 2 (NF2) suffer from sensorineural hearing loss, and associated cochlear nerve compromise in NF2 patients makes auditory brainstem implant (ABI) an attractive treatment option. The long-term outcomes and benefits of the device are still being explored. Methods A retrospective review was conducted for 11 ABI recipients at a single-institution tertiary center between November 2017 and August 2022. Patients diagnosed with NF2 undergoing resection for concurrent vestibular schwannoma (VS) were included. Pre- and postaudiometric assessments were reviewed. Evaluation included pure-tone audiometry and speech testing. Results Our cohort included 11 patients with a median age of 34 years. All patients underwent a translabyrinthine approach for implant placement with concurrent VS resection. Average tumor size of VS was 2.87 cm. Preoperatively, 8 patients had pure-tone averages with no response at 110 dB, 2 were within mild–moderate hearing loss (25–45 dB), and one patient had a PTA of profound loss (92 dB). Postoperatively, 9 (81%) patients had improvement in PTA. In total, seven patients reported mild side effects upon ABI activation which included dizziness (n = 2), tinnitus (n = 1), and abdominal and lower extremity tingling sensation (n = 3). Of the seven patients with early speech perception (ESP) scores, five had a score >75%, indicating the auditory ability to detect pattern perception upon auditory stimulation through the ABI alone. Conclusion Nine of 11 patients derived benefits from ABI placement. These findings demonstrate that ABI placement during concurrent VS resection can provide a significant hearing benefit for NF2 patients. [ABSTRACT FROM AUTHOR]

Objective·To develope an auditory brainstem implant (ABI) vocoder based on cochlear implant (CI) vocoder characteristics and ABI electrode array topology, and to verify its reliability.Methods·An "n-of-m" coding strategy CI/ABI vocoder was constructed based on MATLAB. Within each frame, only the envelopes of the n channels with the highest energy were selected. The interaction coefficient (IC) (range: 1‒3), channel numbers (range: 5‒22), and electrode array topology (CI/ABI) were adjustable parameters, allowing for the synthesis of simulated speech. Psychoacoustic evaluation was employed, recruiting normal hearing subjects to perform closed-set simulated phoneme perception. The phoneme recognition accuracy (20 vowel questions/condition, 11 consonant questions/condition) was compared with the corresponding conditions of CI and ABI from reference literature to determine the IC value of the vocoder and verify its reliability.Results·The vocoder successfully synthesized all test stimuli. In the closed-set CI-simulated speech recognition, the simulated vowel and consonant recognition accuracy for IC2 and IC3 conditions showed no significant difference compared to the accuracy reported in the CI reference literature (P>0.05). The difference in vowel and consonant accuracy between IC2 and the literature was smaller than that between IC3 and the literature (vowel |d|=1.6% vs. 20%, consonant |d|=8.4% vs. 9.9%), thus determining the optimal interaction coefficient of this model as 2. Subsequently, when modifying the electrode array topology to ABI, it was found that the simulated phoneme recognition accuracy for a 16-channel ABI was significantly lower than that for the 16-channel CI group, consistent with the reported literature. The simulated vowel and consonant accuracy within the 5‒8 channel range for ABI showed no significant difference (P>0.05), also aligning with the trend reported in the literature.Conclusion·A CI/ABI vocoder based on "n-of-m" coding strategy is established and the optimal IC is determined. The established ABI encoder has been evaluated for high reliability through psychoacoustic experiments. It provides suitable technical means for validating ABI-specific coding strategies.

Introduction: Auditory performance and language proficiency in young children who utilize auditory brainstem implants (ABIs) throughout the first 3 years of life are difficult to predict. ABI users have challenges as a result of delays in language proficiency and the acquisition of reading comprehension, even if ABI technology offers auditory experiences that enhance spoken language development. The aim of this study was to evaluate about the impact of language proficiency on reading comprehension skills in children with ABI. Method: In this study, 20 children with ABI were evaluated for their reading comprehension abilities and language proficiency using an Informal Reading Inventory, Test of Early Language Development-Third Edition (TELD-3), Categories of Auditory Performance-II (CAP-II), and Speech Intelligibility Rating (SIR). Three distinct aspects of reading comprehension were assessed and analyzed to provide a composite score for reading comprehension abilities. TELD-3, which measures receptive and expressive language proficiency, was presented through spoken language. Results: Studies have shown that there was a relationship between language proficiency and reading comprehension in children with ABI. In the present study, it was determined that the total scores of reading comprehension skills of the children who had poor language proficiency and enrolled in the school for the deaf were also low. The children use short, basic sentences, often repeat words and phrases, and have a restricted vocabulary. In addition, the children had difficulty reading characters and detailed paragraphs and could not remember events in a logical order. Conclusion: Children with ABI may potentially have complicated reading comprehension abilities due to lack of access to all the speech formants needed to develop spoken language. In addition, variables affecting the reading levels of children with ABI include factors such as age at implantation, duration of implant use, presence of additional disability, communication model, and access to auditory rehabilitation. The reading comprehension skills of ABI users were evaluated in this study for the first time in the literature and may constitute a starting point for the examination of variables affecting reading comprehension in this area. [ABSTRACT FROM AUTHOR]

Purpose: This retrospective monocentric study aimed to evaluate long-term auditory brainstem implant (ABI) function in patients with neurofibromatosis type 2, and to investigate the prognostic factors for ABI use. Methods: Between 1997 and 2022, 27 patients with at least five years of follow-up underwent implantation with 32 ABIs. At 1- and 5-years post-implantation and at last follow-up, ABIs were classified as used or non-used and the size of the ipsilateral tumor was recorded. For patients who used their ABIs, we assessed speech perception (disyllabic words, MBAA sentences) in quiet conditions with the ABI only, by lip-reading (LR), and with a combination of the two (ABI + LR). Hearing improvement was calculated as Δ ABI = (ABI + LR)–LR scores. Predictive factors for ABI use were analyzed. Results: One year post-implantation, 74% patients were ABI-users and 66% of the ABIs were used. Two of these patients were non-users at five years, and another two at last follow-up (14 ± 5.2 years); 54% of the patients were ABI-users at last follow-up. Δ ABI revealed a hearing improvement of 32–41% (disyllabic words) and 28–37% (MBAA sentences). Among 16 ABIs with at least LR improvement at 1-year post-implantation, 4 decreased their performance, coinciding with a large growing ipsilateral tumor in 3/4 ABIs. We identified no significant prognostic factors for ABI use. Conclusions: ABIs are indicated in case of bilateral deafness with a non-functional cochlear nerve. Half the patients with ABIs used their implants and auditory performance remained stable over time, except in cases of ipsilateral tumor growth. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiaotong University (Medical Science) is the property of Journal of Shanghai Jiaotong University (Medical Science) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: This study aimed to evaluate attention, memory, and language skills in children with auditory brainstem implants and cochlear implants. Methods: This study included 20 children with auditory brainstem implants (ABI) and 20 cochlear implanted (CI) children between the ages of 6 years and 8 years 11 months and their families. "Test of Language Development: Primary (TOLD-P:4)" was used to assess language skills, "STROOP Test, Visual-Aural Digit Span (VADS) test, and Cancellation Test" were used to evaluate attention and memory skills. In addition, the functional outcomes of hearing skills in daily life were scored by "Auditory Behavior in Everyday Life (ABEL) scale". The significance level was determined as 0.05. Results: Children with ABI showed lower language skills than children with CI in terms of TOLD-P:4 language test scores, STROOP sub-test completion times, and the VADS and Cancellation test scores (p < 0.05). In addition, statistically significant correlations were found between language, attention, memory skills, and auditory behavior scale. Conclusions: This study is one of the limited numbers of studies investigating cognitive processes in children with ABI. Since attention and memory are correlated with language skills, it is recommended that the development of cognition should be considered in follow-up and intervention approaches of children with ABI and/or CI. [ABSTRACT FROM AUTHOR]

BACKGROUND: NF2-schwannomatosis (NF2) is an autosomal dominant disorder prone to hearing loss. Auditory brainstem implants (ABIs) offer a promising solution for hearing rehabilitation in NF2. OBJECTIVE: To synthesize existing literature on ABI implantation in NF2, focusing on audiological outcomes and ABI-related complications. METHODS: The systematic review followed PRISMA guidelines and was registered in the PROSPERO database (CRD42022362155). Relevant studies were identified by searching PubMed, EMBASE, CENTRAL, CMB, and CNKI from inception to August 2023. Data on environmental sound discrimination, open-set discrimination, closed-set discrimination, and ABI-related complications were extracted and subjected to meta-analysis. Publication bias was evaluated using funnel plots and Egger's test. RESULTS: Thirty-three studies were included. The pooled estimate was 58% (95% CI 49–66%) for environmental sound discrimination and 55% (95% CI 40–69%) for closed-set discrimination. Regarding open-set discrimination, the pooled estimates were 30% (95% CI 19–42%) for sound only, 46% (95% CI 37–54%) for lip-reading only, and 63% (95% CI 55–70%) for sound plus lip-reading. The pooled occurrence of ABI-related complications was 33% (95% CI 15–52%). CONCLUSION: This meta-analysis underscores the effectiveness and safety of ABIs in NF2, providing valuable insights for evidence-based decision-making and hearing rehabilitation strategies. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the everyday listening status of pediatric ABI users using the Turkish ABEL questionnaire. Methods: The study included 33 parents of children with auditory brainstem implant, and 28 parents of children with cochlear implant were included as a control group. All implant users were between the ages of 4–14. Parents answered the ABEL questionnaire to assess their child's auditory behavior in their daily living environment. In addition, Categories of Auditory Performance (CAP) and Speech Intelligibility Rating (SIR) scales were used to evaluate speech perception and production. Results: Auditory-aural, auditory awareness and ABEL total score of ABI users were statistically significantly lower than the CI group (p < 0.05). There was no statistically significant difference between the groups in the Conversational/Social skills subgroups. It was found that as the duration of ABI use increased, auditory-verbal, social skills and total scores increased significantly. In addition, correlations were obtained between ABEL total and subscale scores and CAP and SIR scores. Conclusions: Parents believe that their children adapt nicely to ABI and are aware of environmental sounds. This study reveals the auditory, aural, and social skills of children using ABI through the regards of their parents. This study showed that the ABEL questionnaire, which was used in previous studies to express parental views of children with hearing aids and cochlear implants, can also be used for parents of children using ABI. [ABSTRACT FROM AUTHOR]

• First priority in electrically evoked auditory brainstem responses (EABR) is the differentiation of biological from artifact responses by verifying the adequate time frame between > 0.2 ms and < 4 ms. • The New EABR Classification is easy to apply by identification of 3-, 2- or 1-peak morphologies or complete absence. • Presence of any EABR peaks is superior for prediction of auditory function than any evaluation of deformation. In auditory brainstem implant (ABI) surgery, array placement may be optimized by electrophysiological information of adequate brainstem activation gained from electrically evoked auditory brainstem responses (EABR). This study aims 1) to characterize in detail the EABR from ABI implantation, 2) to introduce an EABR Classification Scheme, and 3) to analyze data for their correlation with individual patients' findings. Out of a continuous series of 54 patients who received an ABI between 2005 and 2019, 23 Neurofibromatosis Type 2 patients with complete documentation of 154 recordings were selected for offline analysis and for development and evaluation of a new EABR Classification Scheme comprising Class A: three vertex positive peaks, Class B:two peaks, Class C: a combination of one peak and a second melted double peak, Class D: one sole vertex positive peak and Class E: no peaks. All 23 subjects showed EABR at final ABI position and experienced auditory sensations at first activation. The most frequent morphology consisted of two peaks, Classes B and C. Identified mean latencies were for P1 0.42 ms (±0.095), P2 1.42 ms (±0.244) and P3 2.41 ms (±0.329). Peak latencies correlated positively with tumor extensions (p < 0.005). This study provides clear instructions on optimal EABR performance and evaluation. The new EABR Classification Scheme relies on a fast "online" identification of vertex positive peaks at the estimated post-artifact phase. The variability in EABR morphology provides an individual snapshot of the actual structural and functional status of the brainstem. [ABSTRACT FROM AUTHOR]

We present a pitch discrimination test performed by five experienced adult auditory brainstem implant (ABI) users with neurofibromatosis type 2 (NF2). The ability to discriminate frequency/pitch from different channels on the implant may be an important factor in improving speech performance. The pitch discrimination ability was evaluated by using a triangle test compared to adjacent contacts and the speech perception was measured by the Swedish three-digit test. The test was easy to perform, and all patients were able to answer reliably, even though it cannot be ruled out that patients used attributes other than pitch to differentiate between sounds. Due to the limited number of patients and small variation in results, no conclusive correlations could be made regarding pitch discrimination and auditory outcome. There was a tendency for poorer ability to discriminate pitch (discrimination of tonotopically adjacent electrodes) at testing to result in poorer speech results.

Objective: To investigate the results of cochlear implantation in subjects with neurofibromatosis type 2 (NF2) and bilateral vestibular schwannomas (VS). Study Design: Retrospective case series. Setting: University-based tertiary referral center. Subjects: Five subjects with NF2 and severe-to-profound sensorineural hearing loss. Intervention: Cochlear implantation. Main Outcome Measure: Surgical outcomes and audiometric performance after cochlear implantation. Results: Five subjects (3 female, 2 male) were included in the study. The mean age at the time of implantation was 54 years old (range 35-78 years). Follow-up after cochlear implantation averaged 38 months (range 21-106 months). In the 5 implanted ears, 2 had no prior treatment, 1 had undergone prior radiation therapy, 1 underwent prior microsurgical removal, and 1 underwent prior microsurgical removal with adjuvant radiation therapy. The mean ipsilateral VS dimensions at time of implantation were 14 mm × 7.2 mm × 6.1 mm (mediolateral × anteroposterior × craniocaudal). Following cochlear implant activation, all 5 subjects achieved sound awareness, open set speech recognition, and 4 continue to be daily users of the devices. Conclusion: Cochlear implantation is a viable hearing rehabilitation option for subjects with NF2 and severe-to-profound sensorineural hearing loss. All subjects reported benefit with their cochlear implant, including open set speech recognition, enhanced lip-reading skills and environmental awareness of sound. Four subjects continued to demonstrate improved open-set speech recognition at the time of their last evaluations. [ABSTRACT FROM AUTHOR]

Auditory brainstem implantation (ABI) is a relative recent development in paediatric hearing restoration. Consequently, young-implanted children's productive language has not received much attention. This study investigated speech intelligibility of children with ABI (N = 3) in comparison to children with cochlear implants (CI) and children with typical hearing (TH). Spontaneous speech samples were recorded from children representing the three groups matched on cumulative vocabulary level. Untrained listeners (N = 101) rated the intelligibility of one-word utterances on a continuous scale and transcribed each utterance. The rating task yielded a numerical score between 0 and 100, and similarities and differences between the listeners' transcriptions were captured by a relative entropy score. The speech intelligibility of children with CI and children with TH was similar. Speech intelligibility of children with ABI was well below that of the children with CI and TH. But whereas one child with ABI's intelligibility approached that of the control groups with increasing lexicon size, the intelligibility of the two other children with ABI did not develop in a similar direction. Overall, speech intelligibility was only moderate in the three groups of children, with quite low ratings and considerable differences in the listeners' transcriptions, resulting in high relative entropy scores. [ABSTRACT FROM AUTHOR]

We present a pitch discrimination test performed by five experienced adult auditory brainstem implant (ABI) users with neurofibromatosis type 2 (NF2). The ability to discriminate frequency/pitch from different channels on the implant may be an important factor in improving speech performance. The pitch discrimination ability was evaluated by using a triangle test compared to adjacent contacts and the speech perception was measured by the Swedish three-digit test. The test was easy to perform, and all patients were able to answer reliably, even though it cannot be ruled out that patients used attributes other than pitch to differentiate between sounds. Due to the limited number of patients and small variation in results, no conclusive correlations could be made regarding pitch discrimination and auditory outcome. There was a tendency for poorer ability to discriminate pitch (discrimination of tonotopically adjacent electrodes) at testing to result in poorer speech results. [ABSTRACT FROM AUTHOR]

Objective: To present scientific evidence, based on a systematic review of the literature, on the benefit of brainstem implants in auditory rehabilitation and language development in children. Methods: A systematic search was used to identify studies that contain information about the benefit of brainstem implants in the auditory rehabilitation and language development of children. The review was conducted based on a structured literature search, following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) checklist. The search was carried out in the PubMed, Web of Science and Scopus databases, using the combination “Auditory brainstem implants” AND “Pediatric”, without restriction of language, period, and location. The quality assessment of the articles was performed using the Study Quality Assessment Tools. Results: Regarding hearing, children with brainstem implants showed sound detection, access to most speech sounds, basic auditory perception skills, recognition of ambient sounds, recognition of some frequently used words and phrases, in addition to some closed-set word discrimination capability. Expressive and comprehensive language were identified in children using auditory brainstem implants, increasing significantly in the short and long terms in most cases; however, in some of the children, such skills remained stable. Conclusion: The auditory brainstem implant can be considered an effective alternative for children with cochlear malformation and/or auditory nerve deficiency and for those who cannot benefit from cochlear implant surgery.

Purpose: This study aimed to assess the written language skills of children with auditory brainstem implants (ABI). Methods: In this study, 15 children (from second to eighth grades) with ABI were evaluated for their written language abilities using a written expression skill assessment form. Five different features of written expression points were scored and analyzed, yielding a composite score for written expression skills. Results: This study showed that all children with ABI needed more verbal cues than spontaneously written samples. Moreover, these children used short and simple sentences with limited vocabulary and repeated words and sentences. Furthermore, these children were deficient in writing an introduction, the body, and the conclusion paragraphs and could not write events in a logical sequence. Conclusions: The written language skills of children with ABI depend on age at implantation, duration of implant use, and additional handicaps. Written expression skills in children with ABI are highly complex skills. The findings highlight the importance of ABI during the critical language development period and the enhancement of training programs for written language skills in children who underwent ABI. [ABSTRACT FROM AUTHOR]

Background: An electrophysiological investigation with auditory brainstem response (ABR), round window electrocochleography (RW-ECoG), and electrical-ABR (E-ABR) was performed in children with suspected hearing loss with the purpose of early diagnosis and treatment. The effectiveness of the electrophysiological measures as diagnostic tools was assessed in this study. Methods: In this retrospective case series with chart review, 790 children below 3 years of age with suspected profound hearing loss were tested with impedance audiometry and underwent electrophysiological investigation (ABR, RW-ECoG, and E-ABR). All implanted cases underwent pure-tone audiometry (PTA) of the non-implanted ear at least 5 years after surgery for a long-term assessment of the reliability of the protocol. Results: Two hundred and fourteen children showed bilateral severe-to-profound hearing loss. In 56 children with either ABR thresholds between 70 and 90 dB nHL or no response, RW-ECoG showed thresholds below 70 dB nHL. In the 21 infants with bilateral profound sensorineural hearing loss receiving a unilateral cochlear implant, no statistically significant differences were found in auditory thresholds in the non-implanted ear between electrophysiological measures and PTA at the last follow-up (p > 0.05). Eight implanted children showed residual hearing below 2000 Hz worse than 100 dB nHL and 2 children showed pantonal residual hearing worse than 100 dB nHL (p > 0.05). Conclusion: The audiological evaluation of infants with a comprehensive protocol is highly reliable. RW-ECoG provided a better definition of hearing thresholds, while E-ABR added useful information in cases of auditory nerve deficiency. [ABSTRACT FROM AUTHOR]

The auditory brainstem implant (ABI) was originally developed to provide rehabilitation of retrocochlear deafness caused by neurofibromatosis type 2 (NF2). Recent studies of the ABI have investigated outcomes in non-NF2 cohorts, such as patients with cochlear nerve aplasia or cochlear ossification and more recently, intractable tinnitus. New technologies that improve the ABI-neural tissue interface are being explored as means to improve performance and decrease side effects. Innovative discoveries in optogenetics and bioengineering present opportunities to continually evolve this technology into the future, enhancing spatial selectivity of neuronal activation in the cochlear nucleus and preventing side effects through reduction in activation of non-target neuronal circuitry. These advances will improve surgical planning and ultimately improve patients’ audiological capabilities. ABI research has rapidly increased in the 21st century and applications of this technology are likely to continually evolve. Herein, we aim to characterize ongoing clinical, basic science, and bioengineering advances in ABIs and discuss future directions of this technology.

Objectives: This study aims to evaluate the relationship between phoneme recognition skills and language development skills in pediatric auditory brainstem implant (ABI) users. It further intends to identify the delays and problems that may occur in the phoneme recognition skills of children with ABI and shed light on rehabilitation programs. Methods: Our study included 20 children using ABI and another 20 using cochlear implants (CI). They were aged between 6 and 8 years 11 months. The participants exhibited homogenous demographic and audiological characteristics. The Turkish version of the Test of Language Development-Primary: Fourth Edition (TOLDP:4) was used to evaluate the language development skills, and the Turkish version of the Phoneme Recognition Test (PRT) was applied to assess the phoneme recognition skills. Results: There was a statistically significant difference (p < 0.05) in the PRT values as well as in the language development skills between the children with ABI and those with CI. It was observed that the values of the children with CI were significantly higher than those of children with ABI. Conclusion: Although children with ABI were not able to match the skills of their peers with CI, their language development and communication skills improved. It is believed that this study will contribute to the literature by demonstrating that the use of ABI improves phoneme recognition skills in children who are not eligible for CI or who do not adequately benefit from CI. [ABSTRACT FROM AUTHOR]

An auditory brainstem implant (ABI) attempts to restore hearing at patients with bilateral damaged hearing nerve. The optimal placement of the ABI is challenging even with available auditory measures on the brainstem. We present a visual guidance system that aims to assist during intraoperative ABI placement. As a starting point, a surgical probe is navigated and intuitively visualized in the microscope oculars. The system is developed using modular and agile software design techniques. In a usability study, the participants were able to detect invisible targets marked in a phantom image with a millimetric precision. To the best of our knowledge, this is the first time that this kind of visual guidance is presented. In the future, the system will be expanded with surgical instruments used for the ABI placement.

Here, we describe two congenitally deaf male siblings with the same compound heterozygotic, likely pathogenic mutations in the FGF3 gene, associated with the labyrinthine aplasia, microtia and microdontia (LAMM) syndrome. Both children had bilateral cochleovestibular aplasia, precluding cochlear implantation. The elder brother received an auditory brainstem implant (ABI) with very limited auditory responses. During the ABI-surgery of the younger subject, it was discovered that excellent auditory responses could be obtained when the electrode array was placed considerably more caudally and more medially than standard. It was observed that the foramen of Luschka, the entrance to the lateral recess of the fourth ventricle was located more caudally. In view of this observation the good auditory development of the latter child, it was decided to give the older child a contralateral ABI. Again, it turned out that the anatomy of the brainstem was abnormal with a more caudal location of the foramen of Luschka and the cochlear nucleus, and this child is showing good progress with his auditory development. It is concluded that one should be aware of the anatomical differences at the level of the brainstem when placing an ABI in children with this genetic disorder (and most likely also in the LAMM syndrome). This also underpins the need of a multidisciplinary approach with closely collaborating team members and good family guidance when diagnosing and treating children with rare deafness., Competing Interests: The authors declare that there is no conflict of interest., (© The Author(s), 2024.)

Objective: Auditory Brainstem Implants (ABI) are used to restore hearing in patients lacking appropriate cochlear anatomy and/or cochlear nerve. The objective of this study was to examine the Manufacture and User Facility Device Experience (MAUDE) database to analyze adverse events., Study Design: This is a study of a multi-institutional database maintained by the US FDA., Setting: A database analysis was performed via collaboration of multiple clinicians at tertiary referral centers., Methods: The MAUDE database was queried for Medical Device Reports (MDRs) relating to ABIs. MDRs were identified using the advanced search term "Implant, Auditory Brainstem" and reviewing all reports with the basic search term "Brainstem Implant". All collected reports were individually reviewed., Results: A total of 265 individual patient reports were reviewed, of which 55 reports met inclusion criteria. Reports regarding audiologic outcome included failure to provide hearing benefit (n = 27), implant failure/device malfunction (n = 10), and device non-use (n = 6). Postoperative complications included local skin infection (n = 3), CSF leak (n = 3), elevated ICP (n = 1), surgical site dehiscence (n = 1), swelling (n = 1), seroma formation requiring drainage (n = 1), and meningitis (n = 2). Two patients had dislodged magnets during 1.5 Tesla MRI acquisition. There were 35 instances of full explantation of the device and 1 partial removal; 13 patients had a new device implanted following explantation., Conclusions: Poor hearing results, device failure, and non-use were commonly reported causes for explanation in this analysis. This information can aid physicians in counseling patients and family members and managing device expectations., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Purpose: An auditory brainstem implant (ABI) represents an alternative for patients with profound hearing loss who are constrained from receiving a cochlear implant. The positioning of the ABI electrode influences the patient's auditory capacity and, therefore, quality of life and is challenging even with available intraoperative electrophysiological monitoring. This work aims to provide and assess the feasibility of visual-spatial assistance for ABI positioning. Methods: The pose of the forceps instrument that grasps the electrode was electromagnetically navigated and interactively projected in the eyepieces of a surgical microscope with respect to a target point. Intraoperative navigation was established with an experimental technique for automated nasopharyngeal patient registration. Two ABI procedures were completed in a human specimen head. Results: An intraoperative usability study demonstrated lower localization error when using the proposed visual display versus standard cross-sectional views. The postoperative evaluations of the preclinical study showed that the center of the electrode was misplaced to the planned position by 1.58 mm and 3.16 mm for the left and the right ear procedure, respectively. Conclusion: The results indicate the potential to enhance intraoperative feedback during ABI positioning with the presented system. Further improvements consider estimating the pose of the electrode itself to allow for better orientation during placement. [ABSTRACT FROM AUTHOR]

Purpose of reviewElectric stimulation is a potent means of neuromodulation that has been used to restore hearing and minimize tremor, but its application on tinnitus symptoms has been limited. We examine recent evidence to identify the knowledge gaps in the use of electric stimulation for tinnitus treatment.Recent findingsRecent studies using electric stimulation to suppress tinnitus in humans are categorized according to their points of attacks. First, noninvasive, direct current stimulation uses an active electrode in the ear canal, tympanic membrane, or temporal scalp. Second, inner ear stimulation uses charge-balanced biphasic stimulation by placing an active electrode on the promontory or round window, or a cochlear implant array in the cochlea. Third, intraneural implants can provide targeted stimulation of specific sites along the auditory pathway. Although these studies demonstrated some success in tinnitus suppression, none established a link between tinnitus suppression efficacy and tinnitus-generating mechanisms.SummaryElectric stimulation provides a unique opportunity to suppress tinnitus. Challenges include matching electric stimulation sites and patterns to tinnitus locus and type, meeting the oftentimes-contradictory demands between tinnitus suppression and other indications, such as speech understanding, and justifying the costs and risks of electric stimulation for tinnitus symptoms.

Purpose: Magnetic resonance imaging (MRI) is often used to visualize and diagnose soft tissues. Hearing implant (HI) recipients are likely to require at least one MRI scan during their lifetime. However, the MRI scanner can interact with the implant magnet, resulting in complications for the HI recipient. This survey, which was conducted in two phases, aimed to evaluate the safety and performance of MRI scans for individuals with a HI manufactured by MED-EL (MED-EL GmbH, Innsbruck, Austria). Methods: A survey was developed and distributed in two phases to HEARRING clinics to obtain information about the use of MRI for recipients of MED-EL devices. Phase 1 focused on how often MRI is used in diagnostic imaging of the head region of the cochlear implant (CI) recipients. Phase 2 collected safety information about MRI scans performed on HI recipients. Results: 106 of the 126 MRI scans reported in this survey were performed at a field strength of 1.5 T, on HI recipients who wore the SYNCHRONY CI or SYNCHRONY ABI. The head and spine were the most frequently imaged regions. 123 of the 126 scans were performed without any complications; two HI recipients experienced discomfort/pain. One recipient required reimplantation after an MRI was performed using a scanner that had not been approved for that implant. There was only one case that required surgical removal of the implant to reduce the imaging artefact. Conclusion: Individuals with either a SYNCHRONY CI or SYNCHRONY ABI from MED-EL can safely undergo a 1.5 T MRI when it is performed according to the manufacturer's safety policies and procedures. [ABSTRACT FROM AUTHOR]

Copyright of Turkiye Klinikleri Journal of Health Sciences / Türkiye Klinikleri Sağlık Bilimleri Dergisi is the property of Turkiye Klinikleri and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To discuss indications for bilateral auditory brainstem implants (ABIs), compare audiometric outcomes of unilateral vs bilateral ABIs, and determine if patients have improved outcomes with addition of a second-side implant. Study Design: Retrospective review of 24 patients with neurofibromatosis 2 (NF2) who underwent sequential placement of ABIs from 1989 to 2019. Setting: Tertiary referral center. Methods: Charts were reviewed for indication for second-side surgery, use of implants, and audiometric outcomes. Implants placed in the past 30 years were included in the study. Northwestern University Children's Perception of Speech (NU-CHIPS) and/or City University of New York (CUNY) sentence scores were compared in unilateral and bilateral conditions. Results: Indications for a second-side implant included first-side implants with severe nonauditory symptoms (11), marginal audiometric results (9), outdated technology (2), or deterioration of first side (2). Seven patients are bilateral users and 1 patient discontinued bilateral use after a year due to no significant improvement over unilateral use. One patient with initial bilateral use was lost to follow-up. Thirteen patients are unilateral users due to nonaudiometric side effects or poor audiometric outcomes with the first side. Two patients are complete nonusers. Seventy-five percent had improved audiometric outcomes after the second-side implant, and 20% had stable findings. Conclusions: Second-side ABIs should be consider in patients with poor performance from a first-side implant. Most patients demonstrate subjective improvement with the second ABI. More research is needed for better objective assessments of improvements. [ABSTRACT FROM AUTHOR]

Background: 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. Objectives: To investigate the relationship between motor development performance, speech perception, and language performance in children with auditory brainstem implant (ABI). Method: 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. Results: A significant correlation was established between the BOT-2 manual dexterity and MAIS scores (r = 0.827, p < 0.05) and between the manual dexterity and language skills (for expressive language, r = 0.762, p < 0.05; for receptive language, r = 0.650, p < 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 (p < 0.05). Conclusion: 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. [ABSTRACT FROM AUTHOR]

To investigate the postural instability and vestibular functions in children with severe inner ear malformations (IEMs). A prospective case-control study. The study group consisted of 10 children using unilateral auditory brainstem implant (ABI) with labyrinthine aplasia or rudimentary otocyst. The age-matched control groups consisted of 10 unilateral cochlear implant (CI) users with normal inner ear structures and 10 healthy peers. All tests were performed to implant users when the implants were off. All median VOR gains in the ABI group (median anterior, lateral, and posterior canal 0.15, 0.05, and 0.05, respectively, for the non-implanted sides) were significantly lower than those of the control groups (median VOR gains ≥ 0.90 in both control groups). There were no oVEMP and cVEMP responses in the study group. The mean BOT-2 balance scores of the ABI (3.70 ± 1.34) group was dramatically lower than those of the CI (9.40 ± 2.88) and healthy control (16.20 ± 4.16, p < 0.001). The postural instability in children with severe IEMs was higher than those in CI users with normal inner ear structures and healthy peers. The level of deficiency in the labyrinthine was more important for postural stability in children. [ABSTRACT FROM AUTHOR]

Introduction: Preoperative imaging, besides audiological evaluation, plays a major role in evaluation of candidacy for auditory implants, and in particular cochlear implants. It is essential to assess whether the basic criteria necessary for implantation are met. Diagnostic imaging is crucial not only in determining candidacy, but also determining the feasibility of cochlear implantation as it allow to anticipate surgical difficulties which could preclude or complicate the implantation of the device. The aim of the study is to present the protocol for the evaluation of preoperative imaging studies with particular focus on the factors potentially affecting clinical decisions in children qualified for cochlear implantation. Material and method: Preoperative imaging studies of 111 children performed prior to cochlear implantation were analyzed: high-resolution computed tomography (HRCT) of temporal bones and MRI. The assessment was made according to the presented protocol. Results: Pathologies and anomalies identified during the assessment of preoperative imaging studies significantly altered clinical decisions in 30% of patients. In the study group, in 17% of patients inner ear malformations were identified. 2.7% of children were disqualified from a cochlear implantation due to severe congenital inner ear malformations. 9% of the patients have had bacterial meningitis. In 50% of them difficulties related to complete or progressive cochlear ossification occurred. In 4.5% of patients less common surgical approaches other than mastoidectomy with a posterior tympanotomy were applied. Discussion: Preoperative imaging allow for the identification of significant pathologies and anomalies affecting qualification decisions and further treatment. HRCT and MRI are complementary to each other for preoperative imaging. The two modalities in combination allow accurate and optimal evaluation of the anatomical structures prior to implantation. Inner ear malformations and cochlear ossification following meningitis are relatively frequently encountered in children qualified for a cochlear implant. [ABSTRACT FROM AUTHOR]

Objectives: Historically, eventual loss of cochlear nerve function has limited patients with neurofibromatosis type 2 (NF2) to auditory brainstem implants (ABI), which in general are less effective than modern cochlear implants (CI). Our objective is to evaluate hearing outcomes following ipsilateral cochlear implantation in patients with NF2 and irradiated vestibular schwannomas (VS), and sporadic VS that have been irradiated or observed. Methods: Multi-center retrospective analysis of ipsilateral cochlear implantation in the presence of observed and irradiated VS. MESH search in NCBI PubMed database between 1992 and 2019 for reported cases of cochlear implantation with unresected vestibular schwannoma. Results: Seven patients underwent ipsilateral cochlear implantation in the presence of observed or irradiated vestibular schwannomas. Four patients had sporadic tumors with severe-profound contralateral hearing loss caused by presbycusis/hereditary sensorineural hearing loss, and three patients with NF2 lost contralateral hearing after prior surgical resection. Prior to implantation, one VS was observed without growth for a period of 7 years and the others were treated with radiotherapy. Mean post-operative sentence score was 63.9% (range 48-91) at an average of 28 (range 2-84) months follow up. All patients in this cohort obtained open set speech perception. While analysis of the literature is limited by heterogenous data reporting, 85% of implants with observed schwannomas achieved some open set perception, and 67% of patients previously radiated schwannomas. Furthermore, blending literature outcomes for post implantation sentence testing in quiet without lip-reading show 59.0 ± 35% for patients with CI and observed tumors and 55.7 ± 35% for patients with radiated tumors, with both groups ranging 0 to 100%. Conclusion: This retrospective series and literature review highlight that hearing outcomes with CI for VS patients are superior to those achieved with ABI. However, important considerations including imaging, delayed hearing loss, and observation time cannot be ignored in this population. [ABSTRACT FROM AUTHOR]

Purpose: In this article, we will review the mechanisms and natural history of hearing loss in neurofibromatosis type 2 (NF2) and discuss the hearing outcomes with different rehabilitation options. Methods: Review of the published literature. Results: NF2 is a rare autosomal dominant syndrome characterized by vestibular schwannomas and other intracranial and spinal tumors. Bilateral vestibular schwannomas are the hallmark of the disease which occur in 90 to 95% of the patients. As a result, hearing loss will eventually occur in almost all NF2 patients. Deafness can occur from tumor progression or from treatment of vestibular schwannomas and is among the most debilitating aspects of NF2. A number of surgical and non-surgical rehabilitation options are available for these patients including cochlear and auditory brainstem implants. The audiologic outcomes with surgical rehabilitation options have been variable but most patients are able to achieve sound awareness and benefit from auditory cues in lip reading. Conclusion: Early identification and treatment of NF2 patients can help in achieving better hearing outcomes in the pediatric population. An increasing number of NF2 patients are receiving open set word understanding with refinement in surgical techniques. [ABSTRACT FROM AUTHOR]

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Objectives/hypothesis: To outline a possible decision-making process for sporadic vestibular schwannoma (VS) with contralateral nonserviceable hearing at diagnosis.Study Design: Retrospective case series.Methods: Diagnosed VS was studied in a tertiary referral center from 1995 to 2013.Results: Twenty-eight patients were included, with a mean follow-up of 6.9 years (range = 0.5-20 years). Ten were stage 1, 10 were stage 2, five were stage 3, and three were stage 4. Ipsilateral hearing levels were A (n = 3), B (n = 10), C (n = 7) and D (n = 8) American Academy of Otolaryngology-Head and Neck Surgery classification. Contralateral hearing levels were C (n = 11) and D (n = 17). Initial VS management included surveillance (n = 12) or surgery (n = 16), and four patients were later treated with surgery (n = 3) or stereotactic irradiation (n = 1). Hearing was improved by hearing aids and/or etiological treatment (n = 8), restored by contralateral (n = 15) or ipsilateral (n = 4) cochlear implants (CIs), or ipsilateral auditory brainstem implants (ABIs) (n = 3). Finally, 18 CIs were active daily; 14 of them presented high or moderate benefit with mean open-set dissyllabic word scores (WRS) of 58.1% and sentence recognition scores (SRS) of 69.7%, but only one ABI was still active (WRS of 70% and SRS of 87% with lip reading).Conclusions: When early removal of VS was not necessary, contralateral CI or etiological treatment for hearing loss might be recommended initially. Ipsilateral CI is proposed, whereas VS should be operated on if previous hearing restoration was not successful. ABI should be reserved for the rare cases where a contralateral CI could not be implanted or the cochlear nerve was sectioned during VS removal.Level Of Evidence: 3 Laryngoscope, 130:E407-E415, 2020. [ABSTRACT FROM AUTHOR]

Objectives: To assess the safety and communication performance of auditory brainstem implant (ABI) provision in children who were contraindicated for cochlear implantation and do not have neurofibromatosis type II (NF2).Methods: Communication performance was assessed via a battery of tests up to 24 months after first fitting. Safety was assessed intra-operatively and via post-operative adverse event reports.Results: Ten children participated in the study. The mean communication skills on all 8 tests for which inferential statistics were possible increased significantly from pre-operatively to 12 months and either again increased significantly or remained stable from 12 to 24 months. Communication development was variable: some children achieved high scores while others did not. Two serious adverse events that were device or procedure-related were reported and successfully resolved.Discussion: ABI provision in this population group was safe. Participants' auditory abilities were significantly better after 24 months of ABI use than at pre-implantation. Development was slower than that of children with a cochlear implant but may continue progressing after 24 months of use.Conclusion: ABI provision and use is safe and allows significant auditory development in children without NF2 who are contradicted for cochlear implantation. [ABSTRACT FROM AUTHOR]

Radiotracers offer unique options for brain imaging of functional and molecular processes related to hearing. Such imaging can be applied in a broad spectrum of situations from preclinical research to clinical patient care. Functional imaging to assess activation in brain regions and networks involved in auditory processing uses markers of blood flow or energy-metabolism in well-defined conditions with and without auditory stimulation. Molecular markers can be used in hearing research for example to study changes in inhibitory neurotransmission systems related to hearing loss. For imaging either positron emission tomography (PET) or single-photon emission computed tomography (SPECT) are employed. Data analysis can encompasses voxel-wise statistical analysis of activation and calculation of quantitative parameters like receptor binding-potentials based on bio-kinetic modeling. Functional imaging has been frequently used in the context of auditory implantation. Before implantation it aims to assess intactness of the central auditory pathway and prognosis. After implantation it is used to improve understanding of the outcome with respect to auditory function and finally speech understanding, e.g. by measuring correlates of central auditory processing and neuroplasticity.

Objective: Pediatric data regarding treatment via an auditory brainstem implant (ABI) remains sparse. The authors aimed to describe their experience at their institution and to delineate associated demographic data, audiometric outcomes, and surgical parameters., Methods: An IRB-approved, retrospective chart review was conducted among the authors' pediatric patients who had undergone auditory brainstem implantation between 2012 and 2021. Demographic information including sex, age, race, coexisting syndrome(s), history of cochlear implant placement, average duration of implant use, and follow-up outcomes were collected. Surgical parameters collected included approach, intraoperative findings, number of electrodes activated, and complications., Results: A total of 19 pediatric patients had an ABI placed at the authors' institution, with a mean age at surgery of 4.7 years (range 1.5-17.8 years). A total of 17 patients (89.5%) had bilateral cochlear nerve aplasia/dysplasia, 1 (5.3%) had unilateral cochlear nerve aplasia/dysplasia, and 1 (5.3%) had a hypoplastic cochlea with ossification. A total of 11 patients (57.9%) had a history of cochlear implants that were ineffective and required removal. The mean length of implant use was 5.31 years (0.25-10 years). Two patients (10.5%) experienced CSF-related complications requiring further surgical intervention. The most recent audiometric outcomes demonstrated that 15 patients (78.9%) showed improvement in their hearing ability: 5 with sound/speech awareness, 5 able to discriminate among speech and environmental sounds, and 5 able to understand common phrases/conversation without lip reading. Nine patients (47.4%) are in a school for the deaf and 7 (36.8%) are in a mainstream school with support., Conclusions: The authors' surgical experience with a multidisciplinary team demonstrates that the retrosigmoid approach for ABI placement in children with inner ear pathologies and severe sensorineural hearing loss is a safe and effective treatment modality. Audiometric outcome data showed that nearly 79% of these patients had an improvement in their environmental and speech awareness. Further multicenter collaborations are necessary to improve these outcomes and potentially standardize/enhance electrode placement.

Patients with neurofibromatosis type 2 develop bilateral vestibular schwannomas with progressive hearing loss. Auditory brainstem implants (ABIs) stimulate hearing in the cochlear nuclei and show promise in improving hearing. Here, we assess the impact of ABI on hearing over time by systematically reviewing the literature and re-analyzing available individual patient data. A multidatabase search identified 3 studies with individual patient data of longitudinal hearing outcomes after ABI insertion in adults. Data were collected on hearing outcomes of different sound complexities from sound to speech using an ABI ± lip reading ability plus demographic data. Because of heterogeneity each study was analyzed separately using random effects multilevel mixed linear modeling. Across all 3 studies (n = 111 total) there were significant improvements in hearing over time from ABI placement (P < 0.000 in all). Improvements in comprehension of sounds, words, sentences, and speech occurred over time with ABI use + lip reading but lip reading ability did not improve over time. All categories of hearing complexity had over 50% comprehension after over 1 year of ABI use and some subsets had over 75% or near 100% comprehension. Vowel comprehension was greater than consonant, and word comprehension was greater than sentence comprehension (P < 0.0001 in both). Age and sex did not predict outcomes. ABIs improve hearing beyond lip reading alone, which represents baseline patient function prior to treatment, and the benefits continue to improve with time. These findings may be used to guide patient counseling regarding ABI insertion, rehabilitation course after insertion, and future studies. [ABSTRACT FROM AUTHOR]

Auditory brainstem implants (ABIs) restore hearing to deaf individuals not eligible for cochlear implants. Speech comprehension in ABI users is generally poor compared to that of cochlear implant users, and side effects are common. The poor performance may result from activating broad areas and multiple neuronal populations of the cochlear nucleus, however detailed studies of the responses to surface stimulation of the cochlear nucleus are lacking. A conformable electrode array was microfabricated to fit on the rat's dorsal cochlear nucleus (DCN). It hosts 20 small electrodes (each 100 μm diam.). The array was tested by recording evoked potentials and neural activity along the tonotopic axis of the inferior colliculus (IC). Almost all bipolar electrode pairs elicited responses, in some cases with an even, or relatively constant, pattern of thresholds and supra-threshold measures along the long axis of the array. This pattern suggests that conformable arrays can provide relatively constant excitation along the surface of the DCN and thus might decrease the ABI side effects caused by spread of high current to adjacent structures. We also examined tonotopic patterns of the IC responses. Compared to sound-evoked responses, electrically-evoked response mappings had less tonotopic organization and were broader in width. They became more tonotopic when the evoked activity common to all electrodes and the late phase of response were subtracted out, perhaps because the remaining activity is from tonotopically organized principal cells of the DCN. Responses became less tonotopic when inter-electrode distance was increased from 400 μm to 800 μm but were relatively unaffected by changing to monopolar stimulation. The results illustrate the challenges of using a surface array to present tonotopic cues and improve speech comprehension in humans who use the ABI. • A microfabricated conformable electrode array evoked responses when placed on the DCN surface in rats. • The eABR and neural IC responses showed little variation along the long axis of the array, suggesting an even stimulation pattern. • Compared to sound-evoked responses, electrically-evoked responses had less tonotopic organization and were broader. • Tonotopy increased after subtracting the common activity and the late phase of response, perhaps leaving activity of DCN principal cells. [ABSTRACT FROM AUTHOR]

An auditory brainstem implant (ABI) is a surgically implanted central neural auditory prosthesis for the treatment of profound sensorineural hearing loss in children and adults who are not cochlear implant candidates due to a lack of anatomically intact cochlear nerves or implantable cochleae. The device consists of a multielectrode surface array which is placed within the lateral recess of the fourth ventricle along the brainstem and directly stimulates the cochlear nucleus, thereby bypassing the peripheral auditory system. In the United States, candidacy criteria for ABI include deaf patients with neurofibromatosis type 2 (NF2) who are 12 years or older undergoing first- or second-side vestibular schwannoma resection. In recent years, several non-NF2 indications for ABI have been explored, including bilateral cochlear nerve avulsion from trauma, complete ossification of the cochlea due to meningitis, or a severe cochlear malformation not amenable to cochlear implantation. In addition, growing experience with ABI in infants and children has been documented with encouraging outcomes. While cochlear implantation generally remains the first-line option for hearing rehabilitation in NF2 patients with stable tumors or post hearing preservation surgery where hearing is lost but a cochlear nerve remains accessible for stimulation, an ABI is the next alternative in cases where the cochlear nerve is absent and/or if the cochlea cannot be implanted. Herein, we review ABI device design, clinical evaluation, indications, operative technique, and outcomes as it relates to lateral skull base pathology. [ABSTRACT FROM AUTHOR]