RESUMEN
Cochlear implant (CI) users experience diminished music enjoyment due to the technical limitations of the CI. Nonetheless, behavioral studies have reported that rhythmic features are well-transmitted through the CI. Still, the gradual improvement of rhythm perception after the CI switch-on has not yet been determined using neurophysiological measures. To fill this gap, we here reanalyzed the electroencephalographic responses of participants from two previous mismatch negativity studies. These studies included eight recently implanted CI users measured twice, within the first six weeks after CI switch-on and approximately three months later; thirteen experienced CI users with a median experience of 7 years; and fourteen normally hearing (NH) controls. All participants listened to a repetitive four-tone pattern (known in music as Alberti bass) for 35 min. Applying frequency tagging, we aimed to estimate the neural activity synchronized to the periodicities of the Alberti bass. We hypothesized that longer experience with the CI would be reflected in stronger frequency-tagged neural responses approaching the responses of NH controls. We found an increase in the frequency-tagged amplitudes after only 3 months of CI use. This increase in neural synchronization may reflect an early adaptation to the CI stimulation. Moreover, the frequency-tagged amplitudes of experienced CI users were significantly greater than those of recently implanted CI users, but still smaller than those of NH controls. The frequency-tagged neural responses did not just reflect spectrotemporal changes in the stimuli (i.e., intensity or spectral content fluctuating over time), but also showed non-linear transformations that seemed to enhance relevant periodicities of the Alberti bass. Our findings provide neurophysiological evidence indicating a gradual adaptation to the CI, which is noticeable already after three months, resulting in close to NH brain processing of spectrotemporal features of musical rhythms after extended CI use.
Asunto(s)
Estimulación Acústica , Implantación Coclear , Implantes Cocleares , Electroencefalografía , Música , Humanos , Femenino , Masculino , Persona de Mediana Edad , Adulto , Implantación Coclear/instrumentación , Factores de Tiempo , Estudios de Casos y Controles , Potenciales Evocados Auditivos , Personas con Deficiencia Auditiva/psicología , Personas con Deficiencia Auditiva/rehabilitación , Anciano , Percepción Auditiva , Adaptación Fisiológica , Percepción de la Altura TonalRESUMEN
Timing cues such as interaural time differences (ITDs) and temporal pitch are pivotal for sound localization and source segregation, but their perception is degraded in cochlear-implant (CI) listeners as compared to normal-hearing listeners. In multi-electrode stimulation, intra-aural channel interactions between electrodes are assumed to be an important factor limiting access to those cues. The monaural asynchrony of stimulation timing across electrodes is assumed to mediate the amount of these interactions. This study investigated the effect of the monaural temporal electrode asynchrony (mTEA) between two electrodes, applied similarly in both ears, on ITD-based left/right discrimination sensitivity in five CI listeners, using pulse trains with 100 pulses per second and per electrode. Forward-masked spatial tuning curves were measured at both ears to find electrode separations evoking controlled degrees of across-electrode masking. For electrode separations smaller than 3 mm, results showed an effect of mTEA. Patterns were u/v-shaped, consistent with an explanation in terms of the effective pulse rate that appears to be subject to the well-known rate limitation in electric hearing. For separations larger than 7 mm, no mTEA effects were observed. A comparison to monaural rate-pitch discrimination in a separate set of listeners and in a matched setup showed no systematic differences between percepts. Overall, an important role of the mTEA in both binaural and monaural dual-electrode stimulation is consistent with a monaural pulse-rate limitation whose effect is mediated by channel interactions. Future CI stimulation strategies aiming at improved timing-cue encoding should minimize the stimulation delay between nearby electrodes that need to be stimulated successively.
Asunto(s)
Estimulación Acústica , Implantación Coclear , Implantes Cocleares , Señales (Psicología) , Localización de Sonidos , Humanos , Persona de Mediana Edad , Masculino , Femenino , Localización de Sonidos/fisiología , Anciano , Implantación Coclear/instrumentación , Enmascaramiento Perceptual/fisiología , Factores de Tiempo , Personas con Deficiencia Auditiva/rehabilitación , Personas con Deficiencia Auditiva/psicología , Adulto , Estimulación Eléctrica , Discriminación de la Altura Tonal/fisiología , Umbral Auditivo/fisiologíaRESUMEN
HYPOTHESIS: Evaluation of the Slim Modiolar (SM) electrode in temporal bones (TB) will elucidate the electrode's insertion outcomes. BACKGROUND: The SM electrode was designed for atraumatic insertion into the scala tympani, for ideal perimodiolar positioning and with a smaller caliber to minimize interference with cochlear biological processes. METHODS: The SM electrode was inserted into TBs via a cochleostomy. First, the axial force of insertion was measured. Next, TBs were inserted under fluoroscopy to study insertion dynamics, followed by histologic evaluation of electrode placement and cochlear trauma. A subset of TBs were inserted with the Contour Advance (CA) electrode for comparison. RESULTS: Sixteen of 22 insertions performed to measure the axial force of insertion had flat or near zero insertion force profiles. Six insertions had increased insertion forces, which were attributed to improper sheath depth before electrode insertion. Under real-time fluoroscopy, 23 of 25 TBs had uneventful insertion and good perimodiolar placement. There was 1 scala vestibuli insertion due to suboptimal cochleostomy position and 1 tip roll over related to premature electrode deployment. When compared with the CA electrode, 14 of 15 insertions with the SM electrode resulted in a more perimodiolar electrode position. No evidence of trauma was found in histologic evaluation of the 24 TBs with scala tympani insertions. CONCLUSION: TB evaluation revealed that the SM electrode exerts minimal insertion forces on cochlear structures, produces no histologic evidence of trauma, and reliably assumes the perimodiolar position. Nonstandard cochleostomy location, improper sheath insertion depth, or premature deployment of the electrode may lead to suboptimal outcomes.
Asunto(s)
Cóclea , Implantación Coclear , Implantes Cocleares , Hueso Temporal , Hueso Temporal/cirugía , Humanos , Implantación Coclear/métodos , Implantación Coclear/instrumentación , Cóclea/cirugía , Cóclea/diagnóstico por imagen , Rampa Timpánica/cirugía , Electrodos ImplantadosRESUMEN
Many children with profound hearing loss have received cochlear implants (CI) to help restore some sense of hearing. There is, however, limited research on long-term neurocognitive outcomes in young adults who have grown up hearing through a CI. This study compared the cognitive outcomes of early-implanted (n = 20) and late-implanted (n = 21) young adult CI users, and typically hearing (TH) controls (n=56), all of whom were enrolled in college. Cognitive fluidity, nonverbal intelligence, and American Sign Language (ASL) comprehension were assessed, revealing no significant differences in cognition and nonverbal intelligence between the early and late-implanted groups. However, there was a difference in ASL comprehension, with the late-implanted group having significantly higher ASL comprehension. Although young adult CI users showed significantly lower scores in a working memory and processing speed task than TH age-matched controls, there were no significant differences in tasks involving executive function shifting, inhibitory control, and episodic memory between young adult CI and young adult TH participants. In an exploratory analysis of a subset of CI participants (n = 17) in whom we were able to examine crossmodal plasticity, we saw greater evidence of crossmodal recruitment from the visual system in late-implanted compared with early-implanted CI young adults. However, cortical visual evoked potential latency biomarkers of crossmodal plasticity were not correlated with cognitive measures or ASL comprehension. The results suggest that in the late-implanted CI users, early access to sign language may have served as a scaffold for appropriate cognitive development, while in the early-implanted group early access to oral language benefited cognitive development. Furthermore, our results suggest that the persistence of crossmodal neuroplasticity into adulthood does not necessarily impact cognitive development. In conclusion, early access to language - spoken or signed - may be important for cognitive development, with no observable effect of crossmodal plasticity on cognitive outcomes.
Asunto(s)
Implantación Coclear , Implantes Cocleares , Cognición , Comprensión , Plasticidad Neuronal , Personas con Deficiencia Auditiva , Humanos , Masculino , Adulto Joven , Femenino , Implantación Coclear/instrumentación , Personas con Deficiencia Auditiva/psicología , Personas con Deficiencia Auditiva/rehabilitación , Adulto , Estudios de Casos y Controles , Adolescente , Factores de Tiempo , Factores de Edad , Pruebas Neuropsicológicas , Memoria a Corto Plazo , Función Ejecutiva , Resultado del Tratamiento , Audición , Corrección de Deficiencia Auditiva/instrumentaciónRESUMEN
Combining a cochlear implant with contralateral acoustic hearing typically enhances speech understanding, although this improvement varies among CI users and can lead to an interference effect. This variability may be associated with the effectiveness of the integration between electric and acoustic stimulation, which might be affected by the temporal mismatch between the two listening sides. Finding methods to compensate for the temporal mismatch might contribute to the optimal adjustment of bimodal devices and to improve hearing in CI users with contralateral acoustic hearing. The current study investigates cortical auditory evoked potentials (CAEPs) in normal hearing listeners (NH) and CI users with contralateral acoustic hearing. In NH, the amplitude of the N1 peak and the maximum phase locking value (PLV) were analyzed under monaural, binaural, and binaural temporally mismatched conditions. In CI users, CAEPs were measured when listening with CI only (CIS_only), acoustically only (AS_only) and with both sides together (CIS+AS). When listening with CIS+AS, various interaural delays were introduced between the electric and acoustic stimuli. In NH listeners, interaural temporal mismatch resulted in decreased N1 amplitude and PLV. Moreover, PLV is suggested as a more sensitive measure to investigate the integration of information between the two listening sides. CI users showed varied N1 latencies between the AS_only and CIS_only listening conditions, with increased N1 amplitude when the temporal mismatch was compensated. A tendency towards increased PLV was also observed, however, to a lesser extent than in NH listeners, suggesting a limited integration between electric and acoustic stimulation. This work highlights the potential of CAEPs measurement to investigate cortical processing of the information between two listening sides in NH and bimodal CI users.
Asunto(s)
Estimulación Acústica , Corteza Auditiva , Implantación Coclear , Implantes Cocleares , Estimulación Eléctrica , Potenciales Evocados Auditivos , Personas con Deficiencia Auditiva , Percepción del Habla , Humanos , Femenino , Masculino , Adulto , Persona de Mediana Edad , Anciano , Implantación Coclear/instrumentación , Corteza Auditiva/fisiopatología , Adulto Joven , Factores de Tiempo , Personas con Deficiencia Auditiva/psicología , Personas con Deficiencia Auditiva/rehabilitación , Tiempo de Reacción , Estudios de Casos y Controles , Audición , Electroencefalografía , Umbral Auditivo , Percepción AuditivaRESUMEN
BACKGROUND: Cochlear implants (CI) are implantable medical devices that enable the perception of sounds and the understanding of speech by electrically stimulating the auditory nerve in case of inner ear damage. The stimulation takes place via an array of electrodes surgically inserted in the cochlea. After CI implantation, cone beam computed tomography (CBCT) is used to evaluate the position of the electrodes. Moreover, CBCT is used in research studies to investigate the relationship between the position of the electrodes and the hearing outcome of CI user. In clinical routine, the estimation of the position of the CI electrodes is done manually, which is very time-consuming. RESULTS: The aim of this study was to optimize procedures of automatic electrode localization from CBCT data following CI implantation. For this, we analyzed the performance of automatic electrode localization for 150 CBCT data sets of 10 different types of electrode arrays. Our own implementation of the method by Noble and Dawant (Lecture notes in computer science (Including subseries lecture notes in artificial intelligence and lecture notes in bioinformatics), Springer, pp 152-159, 2015. https://doi.org/10.1007/978-3-319-24571-3_19 ) for automated electrode localization served as a benchmark for evaluation. Differences in the detection rate and the localization accuracy across types of electrode arrays were evaluated and errors were classified. Based on this analysis, we developed a strategy to optimize procedures of automatic electrode localization. It was shown that particularly distantly spaced electrodes in combination with a deep insertion can lead to apical-basal confusions in the localization procedure. This confusion prevents electrodes from being detected or assigned correctly, leading to a deterioration in localization accuracy. CONCLUSIONS: We propose an extended cost function for automatic electrode localization methods that prevents double detection of electrodes to avoid apical-basal confusions. This significantly increased the detection rate by 11.15 percent points and improved the overall localization accuracy by 0.53 mm (1.75 voxels). In comparison to other methods, our proposed cost function does not require any prior knowledge about the individual cochlea anatomy.
Asunto(s)
Automatización , Implantes Cocleares , Tomografía Computarizada de Haz Cónico , Electrodos Implantados , Procesamiento de Imagen Asistido por Computador , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Implantación Coclear/instrumentación , Cóclea/diagnóstico por imagenRESUMEN
Objective. The cochlear implant (CI) belongs to the most successful neuro-prostheses. Traditionally, the stimulating electrode arrays are inserted into the scala tympani (ST), the lower cochlear cavity, which enables simple surgical access. However, often deep insertion is blocked, e.g. by ossification, and the auditory nerve fibers (ANFs) of lower frequency regions cannot be stimulated causing severe restrictions in speech understanding. As an alternative, the CI can be inserted into the scala vestibuli (SV), the other upper cochlear cavity.Approach. In this computational study, the excitability of 25 ANFs are compared for stimulation with ST and SV implants. We employed a 3-dimensional realistic human cochlear model with lateral wall electrodes based on aµ-CT dataset and manually traced fibers. A finite element approach in combination with a compartment model of a spiral ganglion cell was used to simulate monophasic stimulation with anodic (ANO) and cathodic (CAT) pulses of 50µs.Main results. ANO thresholds are lower in ST (mean/std =µ/σ= 189/55µA) stimulation compared to SV (µ/σ= 323/119µA) stimulation. Contrary, CAT thresholds are higher for the ST array (µ/σ= 165/42µA) compared to the SV array (µ/σ= 122/46µA). The threshold amplitude depends on the specific fiber-electrode spatial relationship, such as lateral distance from the cochlear axis, the angle between electrode and target ANF, and the curvature of the peripheral process. For CAT stimulation the SV electrodes show a higher selectivity leading to less cross-stimulation of additional fibers from different cochlear areas.Significance. We present a first simulation study with a human cochlear model that investigates an additional CI placement into the SV and its impact on the excitation behavior. Results predict comparable outcomes to ST electrodes which confirms that SV implantation might be an alternative for patients with a highly obstructed ST.
Asunto(s)
Implantación Coclear , Implantes Cocleares , Nervio Coclear , Rampa Timpánica , Escala Vestibular , Humanos , Nervio Coclear/fisiología , Rampa Timpánica/fisiología , Rampa Timpánica/cirugía , Escala Vestibular/fisiología , Implantación Coclear/métodos , Implantación Coclear/instrumentación , Electrodos Implantados , Estimulación Eléctrica/métodos , Estimulación Eléctrica/instrumentación , Cóclea/fisiología , Simulación por ComputadorRESUMEN
Contemporary cochlear implants (CIs) use cathodic-leading symmetric biphasic (C-BP) pulses for electrical stimulation. It remains unclear whether asymmetric pulses emphasizing the anodic or cathodic phase may improve spectral and temporal coding with CIs. This study tested place- and temporal-pitch sensitivity with C-BP, anodic-centered triphasic (A-TP), and cathodic-centered triphasic (C-TP) pulse trains on apical, middle, and basal electrodes in 10 implanted ears. Virtual channel ranking (VCR) thresholds (for place-pitch sensitivity) were measured at both a low and a high pulse rate of 99 (Experiment 1) and 1000 (Experiment 2) pulses per second (pps), and amplitude modulation frequency ranking (AMFR) thresholds (for temporal-pitch sensitivity) were measured at a 1000-pps pulse rate in Experiment 3. All stimuli were presented in monopolar mode. Results of all experiments showed that detection thresholds, most comfortable levels (MCLs), VCR thresholds, and AMFR thresholds were higher on more basal electrodes. C-BP pulses had longer active phase duration and thus lower detection thresholds and MCLs than A-TP and C-TP pulses. Compared to C-TP pulses, A-TP pulses had lower detection thresholds at the 99-pps but not the 1000-pps pulse rate, and had lower MCLs at both pulse rates. A-TP pulses led to lower VCR thresholds than C-BP pulses, and in turn than C-TP pulses, at the 1000-pps pulse rate. However, pulse shape did not affect VCR thresholds at the 99-pps pulse rate (possibly due to the fixed temporal pitch) or AMFR thresholds at the 1000-pps pulse rate (where the overall high performance may have reduced the changes with different pulse shapes). Notably, stronger polarity effect on VCR thresholds (or more improvement in VCR with A-TP than with C-TP pulses) at the 1000-pps pulse rate was associated with stronger polarity effect on detection thresholds at the 99-pps pulse rate (consistent with more degeneration of auditory nerve peripheral processes). The results suggest that A-TP pulses may improve place-pitch sensitivity or spectral coding for CI users, especially in situations with peripheral process degeneration.
Asunto(s)
Umbral Auditivo , Implantación Coclear , Implantes Cocleares , Estimulación Eléctrica , Percepción de la Altura Tonal , Humanos , Persona de Mediana Edad , Anciano , Implantación Coclear/instrumentación , Masculino , Femenino , Adulto , Personas con Deficiencia Auditiva/psicología , Personas con Deficiencia Auditiva/rehabilitación , Estimulación Acústica , Diseño de Prótesis , Discriminación de la Altura Tonal , Factores de TiempoRESUMEN
As part of a longitudinal study regarding the benefit of early cochlear implantation for children with single-sided deafness, the current work explored the children's daily device use, potential barriers to full-time device use, and the children's ability to understand speech with the cochlear implant (CI). Data were collected from 20 children with prelingual SSD who received a CI before the age of 2.5 years, from the initial activation of the sound processor until the children were 4.8 to 11.0 years old. Daily device use was extracted from the CI's data logging, while word perception in quiet was assessed using direct audio input to the children's sound processor. The children's caregivers completed a questionnaire about habits, motivations, and barriers to device use. The children with SSD and a CI used their device on average 8.3 h per day, corresponding to 63 % of their time spent awake. All children except one could understand speech through the CI, with an average score of 59 % on a closed-set test and 73 % on an open-set test. More device use was associated with higher speech perception scores. Parents were happy with their decision to pursue a CI for their child. Certain habits, like taking off the sound processor during illness, were associated with lower device use. Providing timely counselling to the children's parents, focused on SSD-specific challenges, may be helpful to improve daily device use in these children.
Asunto(s)
Implantación Coclear , Implantes Cocleares , Percepción del Habla , Humanos , Implantación Coclear/instrumentación , Femenino , Masculino , Niño , Preescolar , Factores de Tiempo , Estudios Longitudinales , Personas con Deficiencia Auditiva/psicología , Personas con Deficiencia Auditiva/rehabilitación , Encuestas y Cuestionarios , Inteligibilidad del Habla , Pérdida Auditiva Unilateral/rehabilitación , Pérdida Auditiva Unilateral/psicología , Pérdida Auditiva Unilateral/fisiopatología , Pérdida Auditiva Unilateral/cirugía , Comprensión , Resultado del Tratamiento , Lenguaje Infantil , Sordera/psicología , Sordera/rehabilitación , Sordera/fisiopatología , Sordera/diagnóstico , Sordera/cirugía , Factores de Edad , Conducta Infantil , Motivación , LactanteRESUMEN
Brain plasticity refers to the brain's ability to reorganize its structure or function in response to experiences, learning, and environmental influences. This phenomenon is particularly significant in individuals with deafness, as the brain adapts to compensate for the lack of auditory stimulation. The aim of this study is to investigate whether cochlear implantation can restore a normal pattern of brain activation following auditory stimulation in cases of asymmetric hearing loss. We used a PET-scan technique to assess brain activity after cochlear implantation, specifically during an auditory voice/non-voice discrimination task. The results indicated a nearly normal pattern of brain activity during the auditory discrimination task, except for increased activation in areas related to attentional processes compared to controls. Additionally, brain activity at rest showed significant changes in implanted participants, including cross modal visuo-auditory processing. Therefore, cochlear implants can restore the brain's activation pattern through long-term adaptive adjustments in intrinsic brain activity.
Asunto(s)
Estimulación Acústica , Adaptación Fisiológica , Implantación Coclear , Implantes Cocleares , Plasticidad Neuronal , Tomografía de Emisión de Positrones , Humanos , Implantación Coclear/instrumentación , Masculino , Femenino , Persona de Mediana Edad , Adulto , Mapeo Encefálico/métodos , Personas con Deficiencia Auditiva/psicología , Personas con Deficiencia Auditiva/rehabilitación , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Audición , Estudios de Casos y Controles , Percepción Auditiva , Pérdida Auditiva Unilateral/fisiopatología , Pérdida Auditiva Unilateral/rehabilitación , Pérdida Auditiva Unilateral/diagnóstico por imagen , Pérdida Auditiva Unilateral/psicología , Sordera/fisiopatología , Sordera/diagnóstico por imagen , Sordera/rehabilitación , Sordera/cirugía , Anciano , Corrección de Deficiencia Auditiva , Discriminación en PsicologíaRESUMEN
For cochlear implant (CI) listeners, holding a conversation in noisy and reverberant environments is often challenging. Deep-learning algorithms can potentially mitigate these difficulties by enhancing speech in everyday listening environments. This study compared several deep-learning algorithms with access to one, two unilateral, or six bilateral microphones that were trained to recover speech signals by jointly removing noise and reverberation. The noisy-reverberant speech and an ideal noise reduction algorithm served as lower and upper references, respectively. Objective signal metrics were compared with results from two listening tests, including 15 typical hearing listeners with CI simulations and 12 CI listeners. Large and statistically significant improvements in speech reception thresholds of 7.4 and 10.3 dB were found for the multi-microphone algorithms. For the single-microphone algorithm, there was an improvement of 2.3 dB but only for the CI listener group. The objective signal metrics correctly predicted the rank order of results for CI listeners, and there was an overall agreement for most effects and variances between results for CI simulations and CI listeners. These algorithms hold promise to improve speech intelligibility for CI listeners in environments with noise and reverberation and benefit from a boost in performance when using features extracted from multiple microphones.
Asunto(s)
Implantes Cocleares , Aprendizaje Profundo , Ruido , Inteligibilidad del Habla , Percepción del Habla , Humanos , Ruido/efectos adversos , Femenino , Masculino , Adulto , Persona de Mediana Edad , Anciano , Algoritmos , Adulto Joven , Implantación Coclear/instrumentaciónRESUMEN
BACKGROUND: The method of stem cell transfer to narrow cochlear canals in vivo to generate hair cells is still an unclear operation. Thus, the development of any possible method that will ensure the usage of medical microrobots in small cochlear workspaces is a challenging procedure. METHODS: The current study tries to introduce a macro-micro manipulator system composed of a 6-DoF industrial serial manipulator as a macro manipulator and a proposed 5-DoF parallel manipulator with dual end effectors as a micro manipulator carrying permanent magnets for tetherless microrobot actuation inside the cochlea. RESULTS: Throughout the study, structural synthesis and kinematic analysis of the proposed micro manipulator were introduced. A prototype of the manipulator was manufactured and its hardware verification procedures were carried out using motion capture cameras and surgical navigation registration methodologies. CONCLUSIONS: Following motion training, the assembled macro-micro manipulator was successfully utilised to actuate a microrobot placed inside a manufactured cochlea mockup model.
Asunto(s)
Cóclea , Diseño de Equipo , Procedimientos Quirúrgicos Robotizados , Cóclea/cirugía , Procedimientos Quirúrgicos Robotizados/instrumentación , Procedimientos Quirúrgicos Robotizados/métodos , Humanos , Movimiento (Física) , Implantación Coclear/métodos , Implantación Coclear/instrumentación , Cirugía Asistida por Computador/instrumentación , Cirugía Asistida por Computador/métodos , Fenómenos BiomecánicosRESUMEN
This multi-center study examined the safety and effectiveness of cochlear implantation of children between 9 and 11 months of age. The intended impact was to support practice regarding candidacy assessment and prognostic counseling of pediatric cochlear implant candidates. Data in the clinical chart of children implanted at 9-11 months of age with Cochlear Ltd devices at five cochlear implant centers in the United States and Canada were included in analyses. The study included data from two cohorts implanted with one or two Nucleus devices during the periods of January 1, 2012-December 31, 2017 (Cohort 1, n = 83) or between January 1, 2018 and May 15, 2020 (Cohort 2, n = 50). Major adverse events (requiring another procedure/hospitalization) and minor adverse events (managed with medication alone or underwent an expected course of treatment that did not require surgery or hospitalization) out to 2 years post-implant were monitored and outcomes measured by audiometric thresholds and parent-reports on the IT-MAIS and LittlEARS questionnaires were collected. Results revealed 60 adverse events in 41 children and 227 ears implanted (26%) of which 14 major events occurred in 11 children; all were transitory and resolved. Improved hearing with cochlear implant use was shown in all outcome measures. Findings reveal that the procedure is safe for infants and that they show clear benefits of cochlear implantation including increased audibility and hearing development.
Asunto(s)
Implantación Coclear , Implantes Cocleares , Humanos , Lactante , Implantación Coclear/instrumentación , Implantación Coclear/efectos adversos , Masculino , Femenino , Implantes Cocleares/efectos adversos , Resultado del Tratamiento , Canadá , Estados Unidos , Factores de Tiempo , Estudios Retrospectivos , Umbral Auditivo , Complicaciones PosoperatoriasRESUMEN
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.
Asunto(s)
Implantación Coclear , Implantes Cocleares , Sordera , Función Ejecutiva , Percepción del Habla , Humanos , Masculino , Niño , Femenino , Preescolar , Sordera/psicología , Sordera/rehabilitación , Sordera/fisiopatología , Sordera/cirugía , Implantación Coclear/instrumentación , Estudios de Casos y Controles , Lenguaje Infantil , Personas con Deficiencia Auditiva/psicología , Personas con Deficiencia Auditiva/rehabilitación , Comprensión , Desarrollo del Lenguaje , Vocabulario , Factores de Tiempo , Resultado del Tratamiento , Inteligencia , Factores de Edad , Pruebas del LenguajeRESUMEN
Frequency importance functions (FIFs) for simulated bimodal hearing were derived using sentence perception scores measured in quiet and noise. Acoustic hearing was simulated using low-pass filtering. Electric hearing was simulated using a six-channel vocoder with three input frequency ranges, resulting in overlap, meet, and gap maps, relative to the acoustic cutoff frequency. Spectral holes present in the speech spectra were created within electric stimulation by setting amplitude(s) of channels to zero. FIFs were significantly different between frequency maps. In quiet, the three FIFs were similar with gradually increasing weights with channels 5 and 6 compared to the first three channels. However, the most and least weighted channels slightly varied depending on the maps. In noise, the patterns of the three FIFs were similar to those in quiet, with steeper increasing weights with channels 5 and 6 compared to the first four channels. Thus, channels 5 and 6 contributed to speech perception the most, while channels 1 and 2 contributed the least, regardless of frequency maps. Results suggest that the contribution of cochlear implant frequency bands for bimodal speech perception depends on the degree of frequency overlap between acoustic and electric stimulation and if noise is absent or present.
Asunto(s)
Estimulación Acústica , Implantes Cocleares , Estimulación Eléctrica , Ruido , Percepción del Habla , Humanos , Ruido/efectos adversos , Implantación Coclear/instrumentación , Personas con Deficiencia Auditiva/psicología , Personas con Deficiencia Auditiva/rehabilitación , Enmascaramiento Perceptual , AdultoRESUMEN
Delayed loss of residual acoustic hearing after cochlear implantation is a common but poorly understood phenomenon due to the scarcity of relevant temporal bone tissues. Prior histopathological analysis of one case of post-implantation hearing loss suggested there were no interaural differences in hair cell or neural degeneration to explain the profound loss of low-frequency hearing on the implanted side (Quesnel et al., 2016) and attributed the threshold elevation to neo-ossification and fibrosis around the implant. Here we re-evaluated the histopathology in this case, applying immunostaining and improved microscopic techniques for differentiating surviving hair cells from supporting cells. The new analysis revealed dramatic interaural differences, with a > 80 % loss of inner hair cells in the cochlear apex on the implanted side, which can account for the post-implantation loss of residual hearing. Apical degeneration of the stria further contributed to threshold elevation on the implanted side. In contrast, spiral ganglion cell survival was reduced in the region of the electrode on the implanted side, but apical counts in the two ears were similar to that seen in age-matched unimplanted control ears. Almost none of the surviving auditory neurons retained peripheral axons throughout the basal half of the cochlea. Relevance to cochlear implant performance is discussed.
Asunto(s)
Umbral Auditivo , Implantación Coclear , Implantes Cocleares , Ganglio Espiral de la Cóclea , Implantación Coclear/instrumentación , Implantación Coclear/efectos adversos , Humanos , Ganglio Espiral de la Cóclea/patología , Ganglio Espiral de la Cóclea/fisiopatología , Células Ciliadas Auditivas Internas/patología , Factores de Tiempo , Supervivencia Celular , Masculino , Audición , Pérdida Auditiva/fisiopatología , Pérdida Auditiva/patología , Pérdida Auditiva/cirugía , Pérdida Auditiva/etiología , Femenino , Células Ciliadas Auditivas/patología , Anciano , Degeneración Nerviosa , Persona de Mediana Edad , Hueso Temporal/patología , Hueso Temporal/cirugíaRESUMEN
Cochlear implant (CI) users often report being unsatisfied by music listening through their hearing device. Vibrotactile stimulation could help alleviate those challenges. Previous research has shown that musical stimuli was given higher preference ratings by normal-hearing listeners when concurrent vibrotactile stimulation was congruent in intensity and timing with the corresponding auditory signal compared to incongruent. However, it is not known whether this is also the case for CI users. Therefore, in this experiment, we presented 18 CI users and 24 normal-hearing listeners with five melodies and five different audio-to-tactile maps. Each map varied the congruence between the audio and tactile signals related to intensity, fundamental frequency, and timing. Participants were asked to rate the maps from zero to 100, based on preference. It was shown that almost all normal-hearing listeners, as well as a subset of the CI users, preferred tactile stimulation, which was congruent with the audio in intensity and timing. However, many CI users had no difference in preference between timing aligned and timing unaligned stimuli. The results provide evidence that vibrotactile music enjoyment enhancement could be a solution for some CI users; however, more research is needed to understand which CI users can benefit from it most.
Asunto(s)
Estimulación Acústica , Percepción Auditiva , Implantes Cocleares , Música , Humanos , Femenino , Masculino , Adulto , Persona de Mediana Edad , Anciano , Percepción Auditiva/fisiología , Adulto Joven , Prioridad del Paciente , Implantación Coclear/instrumentación , Percepción del Tacto/fisiología , Vibración , TactoRESUMEN
PURPOSE: To evaluate a system for otomicrosurgery based on 4K three-dimensional (3D) exoscope technology and apply it to cochlear implantation. METHODS: An open stereoscopic vision-based surgical system, which differs from traditional surgical microscopes, was created by utilizing 4K stereo imaging technology and combining it with low-latency 4K ultra-high-definition 3D display. The system underwent evaluation based on 57 cochlear implantation operations, three designed microscopic manipulations, and a questionnaire survey. RESULTS: The surgical images displayed by the 4K-3D exoscope system (4K-3D-ES) are stereoscopic, clear, and smooth. The use of 4K-3D-ES in cochlear implantation is not inferior to traditional microscopes in terms of intraoperative bleeding and surgical complications, and the surgical duration is not slower or may even be faster than when using traditional microscopes. The results of micromanipulation experiments conducted on 16 students also confirmed this and demonstrated that 4K-3D-ES can be easily adapted. Furthermore, additional advantages of 4K-3D-ES were gathered. Significantly enlarged and high-definition stereoscopic images contribute to the visualization of finer anatomical microstructures such as chordae tympani, ensuring safer surgery. Users feel more comfortable in their necks, shoulders, waists, and backs. Real-time shared stereoscopic view for multiple people, convenient for collaboration and teaching. The ear endoscope and 4K-3D-ES enable seamless switching on the same screen. High-definition 3D images and videos can be saved with just one click, making future publication and communication convenient. CONCLUSION: The feasibility and safety of 4K-3D-ES for cochlear implantation surgery have been demonstrated. The 4K-3D-ES also offers numerous unique advantages and holds clinical application and promotional value.
Asunto(s)
Implantación Coclear , Humanos , Implantación Coclear/métodos , Implantación Coclear/instrumentación , Masculino , Femenino , Niño , Imagenología Tridimensional/métodos , Adulto , Persona de Mediana Edad , Microcirugia/métodos , Microcirugia/instrumentación , Preescolar , Adolescente , Adulto Joven , Anciano , LactanteRESUMEN
In recent years, tools for early detection of irreversible trauma to the basilar membrane during hearing preservation cochlear implant (CI) surgery were established in several clinics. A link with the degree of postoperative hearing preservation in patients was investigated, but patient populations were usually small. Therefore, this study's aim was to analyze data from intraoperative extracochlear electrocochleography (ECochG) recordings for a larger group.During hearing preservation CI surgery, extracochlear recordings were made before, during, and after CI electrode insertion using a cotton wick electrode placed at the promontory. Before and after insertion, amplitudes and stimulus response thresholds were recorded at 250, 500, and 1000 Hz. During insertion, response amplitudes were recorded at one frequency and one stimulus level. Data from 121 patient ears were analyzed.The key benefit of extracochlear recordings is that they can be performed before, during, and after CI electrode insertion. However, extracochlear ECochG threshold changes before and after CI insertion were relatively small and did not independently correlate well with hearing preservation, although at 250 Hz they added some significant information. Some tendencies-although no significant relationships-were detected between amplitude behavior and hearing preservation. Rising amplitudes seem favorable and falling amplitudes disadvantageous, but constant amplitudes do not appear to allow stringent predictions.Extracochlear ECochG measurements seem to only partially realize expected benefits. The questions now are: do gains justify the effort, and do other procedures or possible combinations lead to greater benefits for patients?