Auditory Brainstem Implant Surgery Research Articles

Anatomy of the IV Ventricle Applied to the Auditory Brainstem Implant (ABI)

Introduction: Hearing loss in its different degrees is widely recognized as one of the most common disabilities of humanity, it affects approximately 100 million people around the world, only in the United States there are more than 28 million1 Americans who suffer from it and it is expected These figures will increase significantly in the coming decades. The first Auditory Brainstem Implant (ABI) was developed in 1979 at the House Ear Institute in the United States by Dr. William House and Dr. William Hitselberger. The intricate anatomy of the IV ventricle is of great importance in ABI surgery. The IV ventricle in an ependymal cavity of the rhombencephalon, limited anteriorly by the brainstem and posteriorly by the cerebellum, in terms of its structure it can be divided into a roof, floor and two lateral recesses, it continues towards the cephalad with the cerebral aqueduct and caudally with the central medullary canal. Objective: To value the complex anatomy of the fourth ventricle Materials And Methods: A descriptive observational study was carried out in the chair of Normal Anatomy and Imaging Dr. Luis Dellepiane, from the Universidad del Salvador, CABA. During the months of August and September 2022. 6 cerebellums with brain stem and 3 formolized heads were used. Results: The fourth ventricle is a cavity that lies dorsal to the brainstem, ventral to the cerebellum, and medial to the cerebral peduncles. A floor and a roof are described as limits, in addition to two extensions called lateral recesses. The arrangement of these can be seen when performing a sagittal cut where the fourth ventricle shows the shape of a tent, with the floor being the base with a vental orientation, and the walls the roof with a dorsal orientation. Conclusions: The anatomical knowledge of the complex structure of the fourth ventricle is of vital importance in ABI surgery, it is necessary that the neurosurgeon and the otolaryngologist know the above for a better understanding of its intricate anatomy.

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.

Auditory and language skills in children with auditory brainstem implants

ObjectiveThe aim of this study is to characterize the development of auditory and language skills in children during the first 3 years of auditory brainstem implant (ABI) use. MethodIt is a retrospective longitudinal analysis of auditory and language skills in 12 children and pre-adolescents with pre-lingual deafness following ABI surgery (mean age at surgery: 4 years; age range: 2–11 years). Responses were analyzed aboutInfant Toddler Meaningful Auditory Integration Scale (IT-MAIS), MAIS, and Meaningful Use of Speech Scale (MUSS) at 1, 3, 6, 12, 18, 24, and 36 months after ABI activation. ResultsMaximum IT-MAIS/MAIS and MUSS scores after 3 years of ABI use were 45.35% and 35.28%, respectively. ConclusionPediatric patients exhibit slow progressive development of auditory and language skills following ABI activation.

Bimodal stimulation in children with inner ear malformation: One side cochlear implant and contralateral auditory brainstem implant.

To determine audiological outcomes of children who use a cochlear implant (CI) in one ear and an auditory brainstem implant (ABI) in the contralateral ear. Retrospective case review. Tertiary referral hospital. Twelve children followed with CI and contralateral auditory brainstem implant (ABI) by Hacettepe University Department of Otorhinolaryngology and Audiology in Turkey. All children were diagnosed with different inner ear malformations with cochlear nerve aplasia/hypoplasia. CI was planned in the ear with better sound detection during behavioural testing with inserted ear phones and with better CN as seen on MRI. Due to the limited auditory and speech progress with the cochlear implant, ABI was performed on the contralateral ear in all subjects. Audiological performance and auditory perception skills of children with cochlear nerve deficiency (CND) who use bimodal electrical stimulation with CI and contralateral ABI. Mean age of the subjects was 84.00±33.94months. Age at CI surgery and ABI surgery was 25.00±10.98months and 41.50±16.14months, respectively. However, hearing thresholds only with CI and only with ABI did not reveal significant difference, and auditory perception scores improved with bimodal stimulation. The MAIS scores were significantly improved from unilateral CI to bimodal stimulation (P=.002). Pattern perception and word recognition scores were significantly higher with the bimodal condition when compared to CI only and ABI only conditions. Children with CND showed better performance with CI and contralateral ABI combined. Depending on the audiological and radiological results, bimodal stimulation should be advised for children with CND.

Effect of anesthesia on evoked auditory responses in pediatric auditory brainstem implant surgery.

Electrically evoked auditory brainstem responses (EABR) guide placement of the multichannel auditory brainstem implant (ABI) array during surgery. EABRs are also recorded under anesthesia in nontumor pediatric ABI recipients prior to device activation to confirm placement and guide device programming. We examine the influence of anesthesia on evoked response morphology in pediatric ABI users by comparing intraoperative with postoperative EABR recordings. Retrospective review. Seven children underwent ABI surgery by way of retrosigmoid craniotomy. General anesthesia included inhaled sevoflurane induction and propofol maintenance during which EABRs were recorded to confirm accurate positioning of the ABI. A mean of 7.7 ± 2.8 weeks following surgery, the ABI was activated under general anesthesia or sedation (dexmedetomidine) and EABR recordings were made. A qualitative analysis of intraoperative and postoperative waveform morphology was performed. Seven subjects (mean age 20.6 months) underwent nine ABI surgeries (seven primary, two revisions) and nine activations. EABRs were observed in eight of nine postoperative recordings. In three cases, intraoperative EABRs during general anesthesia were similar to postoperative EABRs with sedation. In one case, sevoflurane and propofol were used for intra- and postoperative recordings, and waveforms were also similar. In four cases, amplitude and latency changes were observed for intraoperative versus postoperative EABRs. Similarity of EABR morphology in the anesthetized versus sedated condition suggests that anesthesia does not have a large effect on far-field evoked potentials. Changes in EABR waveform morphology observed postoperatively may be influenced by other factors such as movements of the surface array. 4 Laryngoscope, 130:507-513, 2020.

Pediatric Auditory Brainstem Implantation: Surgical, Electrophysiologic, and Behavioral Outcomes.

The objectives of this study were to demonstrate the safety of auditory brainstem implant (ABI) surgery and document the subsequent development of auditory and spoken language skills in children without neurofibromatosis type II (NFII). A prospective, single-subject observational study of ABI in children without NFII was undertaken at the University of North Carolina at Chapel Hill. Five children were enrolled under an investigational device exemption sponsored by the investigators. Over 3 years, patient demographics, medical/surgical findings, complications, device mapping, electrophysiologic measures, audiologic outcomes, and speech and language measures were collected. Five children without NFII have received ABIs to date without permanent medical sequelae, although 2 children required treatment after surgery for temporary complications. All children wear their device daily, and the benefits of sound awareness have developed slowly. Intra-and postoperative electrophysiologic measures augmented surgical placement and device programming. The slow development of audition skills precipitated limited changes in speech production but had little impact on growth in spoken language. ABI surgery is safe in young children without NFII. Benefits from device use develop slowly and include sound awareness and the use of pattern and timing aspects of sound. These skills may augment progress in speech production but progress in language development is dependent upon visual communication. Further monitoring of this cohort is needed to better delineate the benefits of this intervention in this patient population.

Paediatric Auditory Brainstem Implantation (ABI): A Journey through Surgery and Outcomes

Introduction: Auditory brain stem implantation (ABI) is an implantable electrode device to treat neural hearing loss, where cochlear implantation (CI) is not possible. ABI system consists of a receiver-stimulator, electrode array and electrode plate internally and a speech processor, microphone and transmitter coil externally. The device is kept on the cochlear nucleus and it stimulates the nucleus by which the patient perceives sound. Knowledge of the anatomical landmarks and variants in anatomy of the brainstem is vital for auditory brainstem implant surgery. Pediatric Auditory Brainstem Implantation is indicated for children with congenital cochlear aplasia, absent/hypoplastic vestibulocochlear nerve (VCN), for whom cochlear implantation is not possible. Methodology: Retro prospective study (From 2006 till 2017) at Auditory implant centre in Madras ENT Research Foundation, which includes 24 children who had undergone ABI surgery and are being followed up for 1 year, post operatively. Aims were to study the anatomical variants and the outcomes of auditory brainstem implant implantation. To determine if different anatomical variants effect placement of ABI electrode. To assess the outcomes by Categories of auditory Performance (CAP) scores and Speech Intelligibility Ratings (SIR) scores. Results: All the candidates had significant audiological and verbal outcomes after the auditory brainstem implantation. Though, there was difficulty in insertion of the electrode in subjects with anatomical variants, the outcomes were comparable with other subjects.

Outcomes following Pediatric Auditory Brainstem Implant Surgery: Early Experiences in a North American Center.

There are no approved Food and Drug Administration indications for pediatric auditory brainstem implant (ABI) surgery in the United States. Our prospective case series aims to determine the safety and feasibility of ABI surgery in pediatric patients <5 years old with congenital deafness at a tertiary North American center. The inclusion criterion was pre- or postlinguistic deafness in children not eligible for cochlear implantation. Seventeen candidates were evaluated (mean ± SD: age, 2.52 ± 0.39 years). Four patients underwent ABI surgery (age, 19.2 ± 3.43 months), including 4 primary procedures and 1 revision for device failure. Spontaneous device failure occurred in another subject postoperatively. No major/minor complications occurred, including cerebrospinal fluid leak, facial nerve injury, hematoma, and nonauditory stimulation. All subjects detected sound with environmental awareness, and several demonstrated babbling and mimicry. Poor durability of older implants underscores need for updated technology.

Pediatric Auditory Brainstem Implant Surgery: A New Option for Auditory Habilitation in Congenital Deafness?

The auditory brainstem implant (ABI) is a neuroprosthetic device that provides sound sensations to individuals with profound hearing loss who are not candidates for a cochlear implant (CI) because of anatomic constraints. Herein we describe the ABI for family physicians. PubMed was searched to identify articles relevant to the ABI, as well as articles that contain outcomes data for pediatric patients (age <18 years) who have undergone ABI surgery. The ABI was originally developed for patients with neurofibromatosis type 2 (NF2) who become deaf from bilateral vestibular schwannomas. Over the past decade, indications for an ABI have expanded to adult patients without tumors (without NF2) who cannot receive a CI and children with no cochlea or cochlear nerve. Outcomes among NF2 ABI users are modest compared to cochlear implant patients, but recent studies from Europe suggest that some non-tumor adult and pediatric ABI users achieve speech perception. The ABI is a reasonable surgical option for children with profound hearing loss due to severe cochlear or cochlear nerve deformities. Continued prospective data collection from several clinical trials in the U.S. will provide greater understanding on long term outcomes that focus on speech intelligibility.

Recent Rehabilitation Experience with Pediatric ABI Users.

The aim of this study is to describe the rehabilitative outcomes of pediatric auditory brainstem implant (ABI) users in the Department of Otolaryngology in the Hacettepe University. It was a retrospective study, and all patients' files were reviewed. The data was collected from 41 children who were fitted with ABI between 2005 and 2013. Inclusion criteria for children in our study are profound, congenital bilateral sensory-neural hearing loss with anomalies (such as cochlear, labyrinthine, and cochlear nerve aplasia) and more than one year of auditory experience with ABI. Post-meningitis patients and neurofibromatosis type 2 (NF2) patients were excluded. Auditory perception was evaluated using the Meaningful Auditory Integration Scale (MAIS), Functioning after Pediatric Cochlear Implantation (FAPCI) instrument, Categories of Auditory Performance (CAP), and Children's Auditory Perception Skills Test in Turkish (CIAT). Speech intelligibility was categorized with speech intelligibility rating (SIR), and language development was assessed using the Test of Early Language Development-Third Edition (TELD-3) and Manchester Spoken Language Development Scale (MSLD). All patients gained basic audiological functions and were able to recognize and discriminate sounds by the third month of ABI surgery. According to the duration of ABI use and learning skills, patients revealed development from word identification to sentence recognition level in a wide spectrum. Preliminary results indicate that all children have gained basic auditory perception skills. On the other hand, language and speech development data were varying among children. Additional handicaps seemed to slow down progression. Secondary improvement was seen at psychosocial areas with respect to behavioral and social adjustment as well as eagerness to start communication.

Systematic Review of Nontumor Pediatric Auditory Brainstem Implant Outcomes.

The auditory brainstem implant (ABI) was initially developed for patients with deafness as a result of neurofibromatosis type 2. ABI indications have recently extended to children with congenital deafness who are not cochlear implant candidates. Few multi-institutional outcome data exist. Herein, we aim to provide a systematic review of outcomes following implantation of the ABI in pediatric patients with nontumor diagnosis, with a focus on audiometric outcomes. PubMed, Embase, and Cochrane. A systematic review of literature was performed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) recommendations. Variables assessed included age at implantation, diagnosis, medical history, cochlear implant history, radiographic findings, ABI device implanted, surgical approach, complications, side effects, and auditory outcomes. The initial search identified 304 articles; 21 met inclusion criteria for a total of 162 children. The majority of these patients had cochlear nerve aplasia (63.6%, 103 of 162). Cerebrospinal fluid leak occurred in up to 8.5% of cases. Audiometric outcomes improved over time. After 5 years, almost 50% of patients reached Categories of Auditory Performance scores >4; however, patients with nonauditory disabilities did not demonstrate a similar increase in scores. ABI surgery is a reasonable option for the habilitation of deaf children who are not cochlear implant candidates. Although improvement in Categories of Auditory Performance scores was seen across studies, pediatric ABI users with nonauditory disabilities have inferior audiometric outcomes.

New outcomes with auditory brainstem implants in NF2 patients.

To determine factors related to high levels of speech recognition in patients with the auditory brainstem implant (ABI). Retrospective case review. International multicenter data from hospitals and tertiary referral facilities. Patients with neurofibromatosis type 2 (NF2) and bilateral vestibular schwannomas. ABIs were placed after the removal of vestibular schwannomas. Demographic and surgical data were collected from 26 patients with ABIs who achieved scores of better than 30% correct identification of sentences presented in quiet listening conditions and without lipreading cues. Scores better than 30% speech recognition of standard sentence test materials (HINT or equivalent) in quiet listening conditions were obtained in 26 of the 84 NF2 patients (31%). ABI speech recognition was correlated with surgical position, length of deafness, the number of distinct pitch electrodes, perceptual levels, and ABI stimulation rate, but not correlated with tumor size, tumor stage, the number of electrodes used, or electrophysiological recordings. This paper presents the consensus opinion from a meeting of surgeons to compare outcomes across ABI surgical centers. The consensus opinion was that brainstem trauma is a primary factor in the variability of outcomes in NF2 patients. The significant co-factors in outcomes implied that ABI surgery should be accomplished with great care to minimize physical and venous trauma to the brainstem. It is clear that high levels of speech recognition, including high levels of open-set speech recognition, are possible with the ABI even in patients with NF2 and large tumors.

Complications in Auditory Brainstem Implant Surgery in Adults and Children

Surgery for hearing restoration with auditory brainstem implantation (ABI) in patients with neurofibromatosis type 2 (NF2) is considered safe, as no increase in postoperative complications related to surgery or device implantation has been observed. Over the last 10 years, we have extended the use of ABI to nontumor (NT) adults and children with cochlear or cochlear nerve malfunctions who would not or did not benefit from a cochlear implant (CI). This article examines the complications encountered in ABI surgery in all patient groups. Retrospective case review. Tertiary referral center. : One hundred fourteen ABI operations were performed in Verona (Italy) from 1997 to 2008 in 83 adults and 31 children. Thirty-six had NF2 (34 adults and 2 children), and 78 (49 adults and 29 children) had NT cochlear and cochlear nerve disorders. A retrosigmoid-transmeatal approach was used in the NF2 cases, and a simple retrosigmoid approach was used in the NT patients. Surgical complications are tabulated according to standard reporting categories and are presented separately and analyzed statistically for NF2, NT adults, and NT children. Complication rates are compared with those of CI and microvascular decompression surgery. ABI surgery has a very low major complication rate, particularly in non-NF2 patients. Minor complications were easily controlled with complete resolution in all cases. Although the potential complications of intradural ABI implantation are more severe than those of a transmastoid approach for CIs, the actual observed complication rates in ABI candidates without NF2 tumors are comparable to those of CI surgery in both adults and children. This study demonstrates that the ABI is a safe procedure when performed by an experienced surgical and rehabilitation team, and its benefits can be extended to a larger population of deaf patients.