Auditory brainstem implants for hearing rehabilitation in NF2-schwannomatosis: A systematic review and single-arm meta-analysis.

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.

Auditory brainstem implantation: surgical experience and audiometric outcomes in the pediatric population.

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.

Evaluation of language, attention, and memory skills in children with auditory brainstem implants.

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.

Comparing Speech Recognition Outcomes Between Cochlear Implants and Auditory Brainstem Implants in Patients With NF2-Related Schwannomatosis.

OBJECTIVE: To compare cochlear implant (CI) and auditory brainstem implant (ABI) performance in patients with NF2-related schwannomatosis (NF2). STUDY DESIGN: Historical cohort. SETTING: Tertiary academic center. PATIENTS: A total of 58 devices among 48 patients were studied, including 27 ABIs implanted from 1997 to 2022 and 31 CIs implanted from 2003 to 2022. Three patients had bilateral ABIs, three had bilateral CIs, three had an ABI on one side and a CI on the other, one had a CI that was later replaced with an ipsilateral ABI, and one had an ABI and CI concurrently on the same side. INTERVENTIONS: CI or ABI ipsilateral to vestibular schwannoma. MAIN OUTCOME MEASURES: Open-set speech perception, consonant-nucleus-consonant word scores, and AzBio sentence in quiet scores. RESULTS: Among all patients, 27 (47%) achieved open-set speech perception, with 35 (61%) daily users at a median of 24 months (interquartile range [IQR], 12-87 mo) after implantation. Comparing outcomes, CIs significantly outperformed ABIs; 24 (77%) CIs achieved open-set speech perception compared with 3 (12%) ABIs, with median consonant-nucleus-consonant and AzBio scores of 31% (IQR, 0-52%) and 57% (IQR, 5-83%), respectively, for CIs, compared with 0% (IQR, 0-0%) and 0% (IQR, 0-0%), respectively, for ABIs. Patients with ABIs were younger at diagnosis and at implantation, had larger tumors, and were more likely to have postoperative facial paresis. CONCLUSION: Many patients with NF2-associated vestibular schwannoma achieved auditory benefit with either a CI or an ABI; however, outcomes were significantly better in those patients who were able to receive a CI. When disease and anatomy permit, hearing rehabilitation with a CI should be considered over an ABI in these patients. Tumor management strategies that increase the ability to successfully use CIs should be strongly considered given the high risk of losing bilateral functional acoustic hearing in this population.

Hearing Rehabilitation in Patients With Neurofibromatosis Type 2: The Quebec's Experience With Auditory Implants.

OBJECTIVE: To review a single-center experience with hearing rehabilitation in patients with neurofibromatosis type 2 (NF2) and to describe the auditory outcomes of cochlear implants (CIs) and auditory brainstem implants (ABI) in this population. STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. PATIENTS: Twelve adult patients with NF2 who received a CI (n = 10) and/or an ABI (n = 5) between 2000 and 2021. INTERVENTIONS: Insertion of a CI and/or an ABI in NF2 patients with bilateral vestibular schwannomas (VSs). MAIN OUTCOME MEASURES: Patients' demographic data, treatment history, hearing evolution, hearing rehabilitation methods, implant details, and auditory outcomes after implantation. RESULTS: Among those who received a CI, five patients had a stable untreated VS, one patient underwent a cochlear nerve preserving surgery, and four patients received radiotherapy treatments. Six patients became regular users of their device. The median open-set sentence recognition scores were as follows: 0.5% preoperatively, 60% at 1 year postoperatively, and 80% on the most recent audiological evaluation. All patients with an ABI were implanted concomitantly with VS surgical excision, and three of them also received radiotherapy treatments. The median open-set sentence recognition scores were as follows: 4% preoperatively, 26% at 1 year postoperatively, and 0% on the most recent evaluation. Three patients became regular ABI users. CONCLUSION: Despite major technological advances, auditory outcomes with ABIs remain deceiving. Considering the overall improvement in postoperative auditory performances provided by CIs compared with ABIs, cochlear implantation standouts as a primary mean of hearing rehabilitation in NF2 patients.

Evaluation of auditory brainstem implant (ABI) users' auditory behavior in everyday life.

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.

Ten-year follow-up of auditory brainstem implants: From intra-operative electrical auditory brainstem responses to perceptual results.

The auditory brainstem implant (ABI) can provide hearing sensation to individuals where the auditory nerve is damaged. However, patient outcomes with the ABI are typically much poorer than those for cochlear implant recipients. A major limitation to ABI outcomes is the number of implanted electrodes that can produce auditory responses to electric stimulation. One of the greatest challenges in ABI surgery is the intraoperative positioning of the electrode paddle, which must fit snugly within the cochlear nucleus complex. While there presently is no optimal procedure for intraoperative electrode positioning, intraoperative assessments may provide useful information regarding viable electrodes that may be included in patients' clinical speech processors. Currently, there is limited knowledge regarding the relationship between intraoperative data and post-operative outcomes. Furthermore, the relationship between initial ABI stimulation with and long-term perceptual outcomes is unknown. In this retrospective study, we reviewed intraoperative electrophysiological data from 24 ABI patients (16 adults and 8 children) obtained with two stimulation approaches that differed in terms of neural recruitment. The interoperative electrophysiological recordings were used to estimate the number of viable electrodes and were compared to the number of activated electrodes at initial clinical fitting. Regardless of the stimulation approach, the intraoperative estimate of viable electrodes greatly overestimated the number of active electrodes in the clinical map. The number of active electrodes was associated with long-term perceptual outcomes. Among patients with 10-year follow-up, at least 11/21 active electrodes were needed to support good word detection and closed-set recognition and 14/21 electrodes to support good open-set word and sentence recognition. Perceptual outcomes were better for children than for adults, despite a lower number of active electrodes.

Evaluation of the non-auditory responses in individuals with auditory brainstem implant.

OBJECTIVES: After auditory brainstem implant (ABI) surgery, stimulation of certain cranial nerves may result in a non-auditory response, and the electrodes that stimulate these nerves may be deactivated. The goals of this study are to compare the number of active electrodes in the initial activation and the last fitting, to investigate non-auditory response types and their frequency as a result of non-auditory stimulation, to compare the placements of deactivated electrodes as a result of non-auditory stimulation in the initial activation and the last fitting. METHODS: The computer software system was used to perform a retrospective analysis of the fitting data of 69 ABI users who underwent auditory brainstem implant surgery between January 1997 and January 2019. The non-auditory response types, deactive electrodes, and the positioning of the deactive electrodes horizontally and vertically were recorded in these users during the initial activation and the last fitting. RESULTS: There was no statistically significant difference between the number of active electrodes in the initial activation and the last fitting. The proportion of the users with deactive electrodes in the initial activation and the last fitting was not statistically significant different. In the horizontal and vertical placement classification, the placement of the deactive electrodes was not statistically different between initial activation and last fitting. The most common type of non-auditory response was facial nerve stimulation at the initial activation and no auditory perception at the last fitting. According to the difference between the number of active and deactive electrodes in the initial activation and the last fitting, as well as the auditory and non-auditory responses, it was found that the ABI users were statistically different between the initial activation and the last fitting. CONCLUSION: The results of this study show that not only auditory but also non-auditory responses occur in most ABI users. In addition, to the best of our knowledge, this study is the first to examine the frequencies of non-auditory response types, and the placement of the electrodes that cause these responses according to horizontal and vertical classifications.

Hearing and language development in children with brainstem implants: a systematic review.

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.

Written language skills in children with auditory brainstem implants.

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.

Evaluation of phoneme recognition skills in pediatric auditory brainstem implant users.

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.

Revision Surgery for Pediatric Nontumor Auditory Brainstem Implant Users: Audiological, Rehabilitative, and Surgical Outcomes.

OBJECTIVE: To report the audiological, rehabilitative, and surgical outcomes of revision surgery for pediatric auditory brainstem implant (ABI) users. STUDY DESIGN: Retrospective cohort. SETTING: Tertiary referral center. PATIENTS: Five pediatric ABI users who had revision surgery for device malfunctions. INTERVENTIONS: Revision surgery for ABI malfunctions. MAIN OUTCOME MEASURES: The findings of free-field audiometry with the device, the Meaningful Auditory Integration Scale, and the pattern discrimination, word identification, sentence recognition, and expressive and receptive language tests before the device failure and after revision surgery were obtained from the patient records and compared. RESULTS: The revision rate for pediatric ABI was 6.45%. The Meaningful Auditory Integration Scale and expressive-receptive language scores showed improvements following revision surgery, while the aided thresholds, pattern perception, and word identification scores did not change. Individual differences in performance for these measures were observed. CONCLUSION: Equal or improved performance after the revision surgeries in the current study showed that revision surgery is successful and important for pediatric ABI users. It is essential to consider remedying the loss of auditory input in sensitive periods of pediatric development.

Safety of 3 Tesla Magnetic Resonance Imaging in Patients With Auditory Brainstem Implants.

OBJECTIVE: To evaluate the safety of 3 Tesla (T) magnetic resonance imaging (MRI) in patients with auditory brainstem implants (ABI) with the magnet removed at implantation and report incidence of complications. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary neurotology ambulatory practice. PATIENTS: Patients with diagnosis of Neurofibromatosis, type 2 (NF2) with functional ABIs. INTERVENTIONS: Observational recordings. MAIN OUTCOME MEASURES: Of the 89 patients meeting inclusion criteria, 7 patients underwent 3T MRI, with a total of 39 scans done. Three patients had 1 scan each, one patient had 4 scans, one patient had 5 scans, one patient had 6 scans, and one patient had 21 scans. The mean time between ABI placement and first 3 T scan was 118 ±â€Š73 months. The most common indication for imaging was surveillance of NF2 lesions. The most frequent scans were MRI brain (25.6%), followed by MRI of cervical (15%), thoracic (15%) and lumbar (15%) spine, and MRI IAC (8%). There were no reported complications for any of the scans. No scans were interrupted due to patient discomfort. There were no device malfunctions. CONCLUSIONS: 3 T MRIs are safe in patients with ABIs as long as the magnet is removed. It is recommended that the magnet be removed at the time of implantation in all NF2 patients, who require frequent surveillance.

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

OBJECTIVES: Factors contributing to auditory brainstem implant (ABI) outcomes are poorly understood. The aims of this study are to (1) characterize ABI electrode array position on postoperative imaging and (2) determine if variability in position is related to perceptual outcomes. DESIGN: Retrospective cohort study. Subjects were selected from the adult ABI recipient population at Massachusetts Eye and Ear. Postoperative three-dimensional (3D) computed tomography (CT) reconstruction of the head was used to measure ABI array position in 20 adult ABI recipients (17 with Neurofibromatosis Type 2 (NF2) and three non-NF2 recipients). Three-dimensional electrode array position was determined based on angles from the horizontal using posterior and lateral views and on distances between the proximal array tip superiorly from the basion (D1), laterally (D2P) and posteriorly (D2L) from the midline. Array position was correlated with perceptual data (in 15 of the 20 recipients who used their ABI). Perceptual data included the number of electrodes that provided auditory sensation, location and type of side effects, level of speech perception (from no sound to open-set word recognition of monosyllables) and the amount of charge required for auditory perception. RESULTS: Although the 3D orientation of the ABI array exhibited a variety of angles, all arrays were posteriorly tilted from the lateral view and most were medially tilted from the posterior view. ABI position relative to the basion from posterior showed mean distances of 1.71 ± 0.42 and 1.1 ± 0.29 cm for D1 and D2, respectively, and a mean D2 of 1.30 ± 0.45 cm from the lateral view. A strong linear negative correlation was found between the number of active electrodes and the distance of the proximal array tip laterally from the basion (D2P; rs = -0.73, p = 0.006) when measured in the posterior view. Although side effects were experienced in all recipients and varied in type and location across the array, electrodes in the middle part of the array tended to elicit auditory sensations while the proximal and distal tips of the array tended to elicit nonauditory side effects. Arrays with and without low charge thresholds appeared to generally overlap in position. However, the two recipients with the best (open-set) speech perception had low charge thresholds and had arrays that were tilted superiorly in the posterior view. CONCLUSION: ABI recipients with better speech perception appear to share a profile of arrays that are tilted superiorly as compared to recipients with lower speech perception levels. These ABI recipients have a high number of active electrodes (10 or more) and require less electrical charge on individual electrodes to achieve optimal stimulation.

ABI-auditory brainstem implant.

The Auditory Brainstem Implant (ABI) is based on the classic cochlear implant (CI) but uses a different stimulation electrode. At MED-EL, the early development activities on ABI started in the year 1994, with the suggestion coming from J. Helms and J. Müller from Würzburg, Germany in collaboration with the Univ. of Innsbruck Austria. The first ABI surgery in a neuro-fibromatosis (NF2) patient with the MED-EL device took place in the year 1997. Later, the indication of ABI was expanded to non-NF2 patients with severe inner-ear malformation, for whom a regular CI will not be beneficial. Key translational research activities at MED-EL in collaboration with numerous clinics investigating the factors that affect the hearing performance amongst ABI patients, importance of early ABI implantation in children, tools in pre-operative assessment of ABI candidates and new concepts that were pursued with the MED-EL ABI device. The CE-mark for the MED-EL ABI to be used in adults and children down to the age of 12 months without NF-2 was granted in 2017 mainly based on two long-term clinical studies in the pediatric population. This article covers the milestones of translational research from the first concept to the widespread clinical use of ABI in association with MED-EL.

Extended Middle Cranial Fossa Approach for Placement of Auditory Brainstem Implants.

OBJECTIVE: Traditionally, auditory brainstem implants (ABIs) have been placed via the translabyrinthine or retrosigmoid approaches. In select patients, a modified extended middle cranial fossa (xMCF) approach with tentorial ligation may be advantageous for vestibular schwannoma (VS) resection and auditory rehabilitation. This manuscript describes the application of this modification of the MCF approach for simultaneous VS resection and ABI placement. PATIENTS: Patients with neurofibromatosis type 2, profound bilateral sensorineural hearing loss, single functioning sigmoid/jugular venous system, and giant (>4 cm) VS. INTERVENTIONS: Simultaneous VS resection and ABI placement via a modified xMCF approach with tentorial ligation. MAIN OUTCOME MEASURES: Extent of tumor removal and brainstem decompression, access to lateral recess of the fourth ventricle, functional hearing improvement, surgical complications. RESULTS: Two patients met indications and underwent surgery. There were no immediate or delayed surgical complications. Both had subtotal tumor removal with significant decompression of the brainstem and ABI placement. One patient achieved voice and environmental sound awareness at 35 to 55 dbHL across frequencies. The second patient presented with failure to thrive and multiple lower cranial neuropathies in addition to the above-listed indications. She was hospitalized multiple times after surgery due to failure to thrive and recurrent aspiration pneumonia. Her device was never activated, and she expired 1 year after surgery. CONCLUSIONS: The xMCF with tentorial ligation is an additional approach for tumor resection and ABI placement in selected patients with neurofibromatosis type 2. Future studies will further define when this approach is most applicable as well as the challenges and pitfalls.

[Auditory brainstem implantation].

In this review, we discuss the auditory brainstem implant (ABI), which is a neuroprosthetic device being an advanced hearing aid in cases of bilateral, profound or complete hearing impairment due to a non-functional or absent cochlear nerve, or an inner ear malformation precluding cochlear implantation. Originally indicated in patients with bilateral vestibular schwannomas caused by neurofibromatosis type 2, the ABI has in recent years seen an increase in the aural rehabilitation of congenitally deaf children. Outcomes for patients are mixed, but generally the device leads to a reasonable improvement in speech perception.

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

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.

Bilateral Auditory Brainstem Implants in Patients With Neurofibromatosis 2.

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.