UNASSIGNED: Proper electrode placement is essential for favorable hearing outcomes following cochlear implantation. Though often used, traditional intraoperative X-ray imaging is time consuming, exposes patients and staff to radiation, and poses interpretational challenges. The Nucleus® SmartNav System, utilizes electrode voltage telemetry (EVT) to analyze the positioning of the electrode array intraoperatively. This study investigates the efficacy of SmartNav in optimizing the efficiency and accuracy of assessing electrode placement.
UNASSIGNED: This prospective clinical study analyzed placement of 50 consecutive Cochlear Corporation cochlear implants conducted at a single institution between March of 2022 and June of 2023. Placement check of electrode array using SmartNav and X-ray was completed and individually assessed. A comparative analysis of SmartNav and X-ray completion times for electrode placement assessment was conducted.
UNASSIGNED: Subjects included nine ears with abnormal anatomy and three reimplants. SmartNav placement check required a total time of 2.12 min compared to X-ray imaging at 14.23 min (p = 1.6E-16, CI 95%). Both SmartNav and X-ray had excellent sensitivity of 100% in identifying appropriate electrode position (p = 1.0). Tip fold-over was identified using both modalities in 3 cases with noted easier interpretation using SmartNav.
UNASSIGNED: The Nucleus® SmartNav System significantly outperformed traditional X-ray imaging, offering a faster and more straightforward approach to assessing electrode positioning during cochlear implant surgery, thereby enhancing surgical efficiency and patient safety.

BACKGROUND: The cochlear implant (CI) is effective for rehabilitating patients with severe to profound sensorineural hearing loss. However, its placement and use have been associated with various complications, such as those affecting the vestibular system. The objective of this study was to compare vestibular function using the video head impulse test (vHIT) in pediatric patients before and after CI placement.
METHODS: A descriptive and retrospective study was conducted. The outcomes of 11 pediatric patients of both sexes with a history of profound hearing loss were evaluated. The results of vestibular-ocular reflex (VOR) gain, saccades, asymmetry, Pérez Rey (PR) index, and VOR/saccade ratio for both ears obtained by the vHIT test before and after CI placement were compared.
RESULTS: Of the 11 patients evaluated, the VOR gain showed that 81.8% had normal function, 18.2% had hypofunction, and no patients had hyperfunction before implantation. No statistically significant differences were found when compared with post-implant off and post-implant on conditions (p > 0.05). The extracted variables, asymmetry, PR index, and the VOR/saccades ratio also showed no statistically significant differences between the pre- and post-implant conditions, whether off or on.
CONCLUSIONS: The vestibular function of pediatric patients did not show significant changes before and after CI placement. The vHIT test is a valuable tool for assessing vestibular function and could be considered a criterion for surgical and rehabilitation decisions in patients undergoing CI placement.
UNASSIGNED: El implante coclear es un dispositivo eficaz para la rehabilitación de pacientes con hipoacusia neurosensorial severa a profunda. Sin embargo, su colocación y uso se ha asociado a diversas complicaciones, entre ellas a nivel del sistema vestibular. El objetivo del presente estudio fue comparar la función vestibular mediante la prueba de videoimpulso cefálico (vHIT) de pacientes pediátricos antes y después de la colocación del implante coclear.
UNASSIGNED: Se llevó a cabo un estudio descriptivo y retrospectivo. Se evaluaron los resultados de 11 pacientes pediátricos de ambos sexos con antecedente de hipoacusia profunda. Se compararon los resultados de ganancia del VOR, sacadas, asimetría, índice PR así como la relación VOR/sacadas para ambos oídos obtenidos mediante la prueba vHIT antes y después de la colocación del implante coclear.
RESULTS: De los 11 pacientes evaluados, la ganancia del VOR mostró que el 81.8% tenía normofunción, 18.2% hipofunción y ningún paciente hiperfunción antes del implante. Al compararlo con la ganancia post implante apagado y post implante encendido no se encontraron diferencias estadísticamente significativas (p > 0.05). Las variables sacadas, asimetría, índice PR así como la relación VOR/sacadas tampoco mostraron diferencias estadísticamente significativas entre las condiciones pre y pos implante ya sea apagado o encendido.
CONCLUSIONS: La función vestibular de pacientes pediátricos no mostró cambios significativos previo y posterior a la colocación del implante coclear. La prueba vHIT es una herramienta útil que permite evaluar la función vestibular y que podría considerarse como criterio para tomar decisiones quirúrgicas en pacientes que se encuentran en protocolo para implante coclear.

We examined the impact of exposure to a signed language (American Sign Language, or ASL) at different ages on the neural systems that support spoken language phonemic discrimination in deaf individuals with cochlear implants (CIs). Deaf CI users (N = 18, age = 18-24 yrs) who were exposed to a signed language at different ages and hearing individuals (N = 18, age = 18-21 yrs) completed a phonemic discrimination task in a spoken native (English) and non-native (Hindi) language while undergoing functional near-infrared spectroscopy neuroimaging. Behaviorally, deaf CI users who received a CI early versus later in life showed better English phonemic discrimination, albeit phonemic discrimination was poor relative to hearing individuals. Importantly, the age of exposure to ASL was not related to phonemic discrimination. Neurally, early-life language exposure, irrespective of modality, was associated with greater neural activation of left-hemisphere language areas critically involved in phonological processing during the phonemic discrimination task in deaf CI users. In particular, early exposure to ASL was associated with increased activation in the left hemisphere\'s classic language regions for native versus non-native language phonemic contrasts for deaf CI users who received a CI later in life. For deaf CI users who received a CI early in life, the age of exposure to ASL was not related to neural activation during phonemic discrimination. Together, the findings suggest that early signed language exposure does not negatively impact spoken language processing in deaf CI users, but may instead potentially offset the negative effects of language deprivation that deaf children without any signed language exposure experience prior to implantation. This empirical evidence aligns with and lends support to recent perspectives regarding the impact of ASL exposure in the context of CI usage.

UNASSIGNED: To characterize practice patterns of intraoperative imaging and/or functional confirmation of cochlear implant electrode location worldwide.
UNASSIGNED: A cross-sectional survey of otolaryngologists performing cochlear implantation was conducted between March 1 and May 6, 2023. Participants were recruited worldwide using an international otologic society membership email list and at professional meetings. Ninety-seven of the 125 invited participants (78%) completed the survey. Participants were categorized by continent.
UNASSIGNED: North American surgeons use intraoperative X-rays more frequently than surgeons in Europe and Asia (p < 0.001). Otolaryngologists in Europe and Asia more frequently use no intraoperative imaging (p = 0.02). There is no regional difference between the intraoperative use of electrophysiologic instruments. European and Asian surgeons implant MED-EL devices (p = 0.012) more frequently than North American surgeons, who more frequently use Cochlear Corporation devices (p = 0.003). MED-EL use is related to less frequent intraoperative X-ray use (p = 0.02). Advanced Bionics use is related to more frequent intraoperative CT use (p = 0.03). No significant association existed between years of practice, number of cochlear implantation surgeries performed yearly, volume of pediatric CI practice, and use of intraoperative tools.
UNASSIGNED: Intraoperative practice for radiologic and functional verification of cochlear implant electrode positioning varies worldwide. Practice guidelines may help establish a standard of care for cochlear implantation.

BACKGROUND: Sensory information obtained from the visual, somatosensory, and vestibular systems is responsible for regulating postural control, and if damage occurs in one or more of these sensory systems, postural control may be altered.
OBJECTIVE: To evaluate and compare the postural sway velocity between children with normal hearing and with sensorineural hearing loss (SNHL), matched by sex and age group, and to compare the postural sway velocity between children with normal hearing and with SNHL, with and without vestibular dysfunction.
METHODS: Cross-sectional study that evaluated 130 children (65 with normal hearing and 65 with SNHL), of both sexes and aged between 7 and 11 years, from public schools of the city of Caruaru, Pernambuco state, Brazil. The postural sway velocity of the center of pressure (COP) was assessed by a force platform, in two directions, anteroposterior (AP) and mediolateral (ML)), in three positions, namely bipedal support with feet together and parallel (parallel feet (PF)), bipedal support with one foot in front of the other (tandem foot (TF)), and single-leg support (one foot (OF)), evaluated with the eyes open and closed.
RESULTS: Children with SNHL demonstrated greater postural sway velocity compared to children with normal hearing in all the positions evaluated, with significant differences in the AP direction, with the eyes open (PF: p = 0.001; TF: p = 0.000; OF: p = 0.003) and closed (PF: p = 0.050; TF: p = 0.005). The same occurred in the ML direction, with the eyes open (PF: p = 0.001; TF: p = 0.000; OF: p = 0.001) and closed (PF: p = 0.002; TF: p = 0.000). The same occurred in relation to vestibular function, where the children with SNHL with an associated vestibular dysfunction demonstrated greater postural sway velocity compared to children with normal hearing in all the positions evaluated, demonstrating significant differences in the AP direction, with the eyes open (TF: p = 0.001; OF: p = 0.029) and eyes closed (PF: p = 0.036; TF: p = 0.033). The same occurred in the ML direction, with the eyes open (TF: p = 0.000) and with the eyes closed (PF: p = 0.008; TF: p = 0.009).
CONCLUSIONS: Children with SNHL demonstrated greater instability of postural control than children with normal hearing in all the directions assessed. Children with SNHL and an associated vestibular dysfunction demonstrated the greatest instability of postural control in this study.

Background: Various representations exist in the literature to visualize electrocochleography (ECochG) recordings along the basilar membrane (BM). This lack of generalization complicates comparisons within and between cochlear implant (CI) users, as well as between publications. This study synthesized the visual representations available in the literature via a systematic review and provides a novel approach to visualize ECochG data in CI users. Methods: A systematic review was conducted within PubMed and EMBASE to evaluate studies investigating ECochG and CI. Figures that visualized ECochG responses were selected and analyzed. A novel visualization of individual ECochG data, the ZH-ECochG Bode plot (ZH = Zurich), was devised, and the recordings from three CI recipients were used to demonstrate and assess the new framework. Results: Within the database search, 74 articles with a total of 115 figures met the inclusion criteria. Analysis revealed various types of representations using different axes; their advantages were incorporated into the novel visualization framework. The ZH-ECochG Bode plot visualizes the amplitude and phase of the ECochG recordings along the different tonotopic regions and angular insertion depths of the recording sites. The graph includes the pre- and postoperative audiograms to enable a comparison of ECochG responses with the audiometric profile, and allows different measurements to be shown in the same graph. Conclusions: The ZH-ECochG Bode plot provides a generalized visual representation of ECochG data, using well-defined axes. This will facilitate the investigation of the complex ECochG potentials generated along the BM and allows for better comparisons of ECochG recordings within and among CI users and publications. The scripts used to construct the ZH-ECochG Bode plot are provided by the authors.

OBJECTIVE: Despite the widespread use and technical improvement of cochlear implant (CI) devices over past decades, further research into the bioelectric bases of CI stimulation is still needed. Various stimulation modes implemented by different CI manufacturers coexist, but their true clinical benefit remains unclear, probably due to the high inter-subject variability reported, which makes the prediction of CI outcomes and the optimal fitting of stimulation parameters challenging. A highly detailed full head model that includes a cochlea and an electrode array is developed in this study to emulate intracochlear voltages and extracochlear current pathways through the head in CI stimulation.
METHODS: Simulations based on the finite element method were conducted under monopolar, bipolar, tripolar, and partial tripolar modes, as well as for apical, medial, and basal electrodes. Variables simulated included: intracochlear voltages, electric field (EF) decay, electric potentials at the scalp and extracochlear currents through the head. To better understand CI side effects such as facial nerve stimulation, caused by spurious current leakage out from the cochlea, special emphasis is given to the analysis of the EF over the facial nerve.
RESULTS: The model reasonably predicts EF magnitudes and trends previously reported in CI users. New relevant extracochlear current pathways through the head and brain tissues have been identified. Simulated results also show differences in the magnitude and distribution of the EF through different segments of the facial nerve upon different stimulation modes and electrodes, dependent on nerve and bone tissue conductivities.
CONCLUSIONS: Full head models prove useful tools to model intra and extracochlear EFs in CI stimulation. Our findings could prove useful in the design of future experimental studies to contrast FNS mechanisms upon stimulation of different electrodes and CI modes. The full-head model developed is freely available for the CI community for further research and use.

Background: In most cases, intralabyrinthine schwannoma (ILS) occurs in patients with unilateral hearing deterioration or neurofibromatosis type II (NF II). The pattern of localization of these tumors varies but mostly affects the cochlea. Extirpation of the cochlear schwannoma, if hidden by the cochlea modiolus, is difficult under the aspect of complete removal. Therefore, a tissue removal device (TRD) was designed and tested in temporal bones. The principle of handling the new device is a pushing and pipe cleaner handling inside the cochlea. This present study aimed to describe the first in vivo experience with the newly developed TRD for removing cochlear intralabyrinthine schwannomas. Methods: In three patients, the TRD was used for the tumor removal of cochlear schwannomas. In two patients with a cochlear schwannoma in combination with a cochlea implantation and one patient suffering from NF II, a cochlear schwannoma was removed with the TRD. The access was performed with a posterior tympanotomy, an enlarged round window approach and an additional second turn access. The device was inserted and extracted gradually from the second turn access until the rings were visible in the second turn access. By pushing and pipe cleaner handling, the tumors were removed. An MRI control was performed on the day postoperatively with a T1 GAD sequence. Results: Tumor removal with the TRD was performed in a 15-min procedure without any complications. An MRI control confirmed complete removal on the postoperative day in all cases. Conclusions: In vivo handling of the device confirmed straightforward handling for the tumor removal. MRI scanning showed complete removal of the tumor by the TRD.

Objectives: The growing adoption of cochlear implants (CIs) necessitates understanding the factors influencing long-term performance and improved outcomes. This work investigated the long-term effect of early activation of CIs on electrode impedance in a large sample of CI users at different time points. Methods: A retrospective study on 915 ears from CI patients who were implanted between 2015 and 2020. According to their CI audio processor activation time, the patients were categorized into early activation (activated 1 day after surgery, n = 481) and classical activation (activated 4 weeks after surgery, n = 434) groups. Then, the impact of the activation times on the electrode impedance values, along the electrode array contacts, at different time points up to two years was studied and analyzed. Results: The early activation group demonstrated lower impedance values across all the electrode array sections compared to the classical activation at 1 month, 1 year, and 2 years post-implantation. At 1 month, early activation was associated with a reduction of 0.34 kΩ, 0.46 kΩ, and 0.37 kΩ in the apical, middle, and basal sections, respectively. These differences persisted at subsequent intervals. Conclusions: Early activation leads to sustained reductions in the electrode impedance compared to classical activation (CA), suggesting that earlier activation might positively affect long-term CI outcomes.

Spoken language development after pediatric cochlear implantation requires rapid and efficient processing of novel, degraded auditory signals and linguistic information. These demands for rapid adaptation tax the information processing speed ability of children who receive cochlear implants. This study investigated the association of speed of information processing ability with spoken language outcomes after cochlear implantation in prelingually deaf children aged 4-6 years. Two domain-general (visual, non-linguistic) speed of information processing measures were administered to 21 preschool-aged children with cochlear implants and 23 normal-hearing peers. Measures of speech recognition, language (vocabulary and comprehension), nonverbal intelligence, and executive functioning skills were also obtained from each participant. Speed of information processing was positively associated with speech recognition and language skills in preschool-aged children with cochlear implants but not in normal-hearing peers. This association remained significant after controlling for hearing group, age, nonverbal intelligence, and executive functioning skills. These findings are consistent with models suggesting that domain-general, fast-efficient information processing speed underlies adaptation to speech perception and language learning following implantation. Assessment and intervention strategies targeting speed of information processing may provide better understanding and development of speech-language skills after cochlear implantation.