|Special Issue of Audiology and Neurotology: Annual Autumn Meeting of the German Audiology & Neurotology Group (ADANO), Berlin October 19th to 20th, 2016|
No abstract available
|Superior Canal Dehiscence Syndrome: Relating Clinical Findings With Vestibular Neural Responses From a Guinea Pig Model|
Hypothesis: In superior canal dehiscence (SCD), fluid displacement of the endolymph activates type I vestibular hair cells in the crista of the affected canal and thus irregular superior canal (SC) neurons in Scarpa's ganglion, which provides the neurophysiological basis for the clinical presentation of SCD. Background: Patients with SCD display sound- and vibration-induced vertigo/nystagmus and increased amplitudes of vestibular evoked myogenic potentials. Methods: Extracellular recordings from n = 25 primary vestibular neurons of 16 female guinea pigs were analyzed. We recorded from the same vestibular neuron before, during and after creating the dehiscence and after closing the dehiscence. Neurobiotin labeling was employed in n = 11 neurons. Results: After SCD, previously unresponsive irregular SC neurons displayed a stimulus-locked increase in discharge during application of air-conducted sound (ACS) or bone-conducted vibration (BCV) for a broad range of frequencies (ACS: 200–4000 Hz; BCV: 500–1500 Hz). This typical response was only observed for irregular SC neurons (n = 19), but not regular SC neurons, or irregular/regular horizontal canal neurons (n = 2 each), and was abolished after closing the dehiscence. Eleven irregular SC neurons responsive to ACS and/or BCV were traced back to calyx synapses in the central crista of the affected superior canal by neurobiotin labeling. Conclusions: Stimulus-locked activation of irregular SC neurons by ACS and BCV is the neurophysiological basis for sound- and vibration-induced vertigo/nystagmus and increased VEMP amplitudes in SCD. The results of the present study help to improve vestibular diagnostics in patients with suspected SCD.
|The Obliteration of Noncritical Size Bone Defects With Bone Dust or Bone Replacement Material (Bioactive Glass S53P4)|
Hypothesis: Bone dust (BD) harvested during operation may be suitable as an autologous obliteration material for noncritical size defects. Bioactive glass (BA) can be an alternative. Background: To treat noncritical size defects, BD and BA are commonly used for obliteration techniques. However, the optimal harvesting method and parameters for BD have not been examined. In this study, we analyzed the osseoregenerative potential of both materials. Methods: Thirteen female merino sheep (7-yr old) underwent surgery on the frontal calvaria. Three defects were inserted. The first defect was considered a reference and remained unfilled, the second defect was filled with BD from the calvaria bone, and the third defect was filled with BA S53P4. The animals were sacrificed after 3 weeks. To evaluate bone regeneration, we used digital volume tomography, bone density measurement, fluorochrome sequence labeling, and histological analysis. Results: All analyses showed quantitative and qualitative bone regeneration 3 weeks after operation. The control blank defect showed significantly less new bone growth than the BD-filled defect. Moreover, bone regeneration occurred from the surrounding bone and showed only a defect bridge in the BD-filled defect. The BA completely filled the defect and had the highest density although the same amount of new mineralized bone generated as in the reference. Conclusion: BD and BA seemed to be suitable bone replacement materials for obliteration techniques because they completely filled the defects. Thus, BD harvested under standardized conditions provided a higher level of osteoreparation potential for the generation of woven bone and establishment of defect bridges.
|Changes of Electrocochleographic Responses During Cochlear Implantation Presented at the Annual Meeting of ADANO 2016 in Berlin|
Objective: To assess by electrocochleography (ECoG) at which times during cochlear implantation changes of cochlear function occur. Methods: Tone bursts with a frequency of 500 or 750 Hz were used as acoustic stimuli. The recording electrode was placed on the promontory and left in an unchanged position for all ECoG recordings. Results: Eight subjects were included. After opening the cochlea, an increase of the amplitude of the ECoG signal was detectable in four subjects (mean change 3.9 dB, range from 0.2 to 10.8 dB). No decreases were detectable after opening the cochlea or during the first half of the insertion of the CI electrode array (mean change 0.5 dB, range from −2.2 to 1.6 dB). During the second half of the insertion, the amplitude of the ECoG signal decreased in four subjects (mean change −2.5 dB, range from −0.04 to −4.8 dB). If a decrease occurred during the second half of the insertion, then the decrease continued in the earliest phase after insertion of the CI electrode array (mean change −2.1 dB, range from −0.5 to −5.8 dB). Conclusion: Pressure changes inside the cochlea can lead to an increase of ECoG signals after opening the cochlea. If detectable, then a decrease of ECoG signals occurs during the second half of the insertion of the CI electrode array and continues in the earliest phase after completed insertion. These findings suggest that cochlear trauma occurs toward the end of the insertion and that trauma-dependent postoperative mechanisms contribute to postoperative hearing loss.
|Long-term Benefit of Unilateral Cochlear Implantation on Quality of Life and Speech Perception in Bilaterally Deafened Patients|
Objective: Cochlear implantation (CI) is a common treatment modality for unilaterally and bilaterally deafened patients as well as patients with severe to profound hearing loss. The aim of our study is the complex evaluation of the improvement and influence of health related quality of life (HRQoL) and auditory performance in cochlear implant patients during a long-term follow-up. Methods: Sixty-one bilaterally, postlingually deafened patients with unilateral CI were included in this prospective study. Assessment tools for auditory performance and HRQoL included the Freiburg Monosyllabic Speech test, Oldenburg Inventory (OI) questionnaire, Nijmegen Cochlear Implant Questionnaire (NCIQ) and 36-item Short Form Survey (SF-36). Data were collected before CI, at 6, 12, and 24 months postoperatively. Results: The assessment tools for speech perception yielded a statistically significant improvement in the Freiburg Monosyllabic Speech test scores and of all subdomain scores of the OI during the 6-month follow-up period. The subdomain scores of the NCIQ and the psychological score of the SF-36 also improved significantly during this follow-up period. All results remained stable thereafter during the 12- and 24-month follow-up. There was a statistically significant correlation between subjective speech perception and HRQoL after CI. Conclusion: This is the first prospective study to show results in regard to speech perception and HRQoL and their correlation during a 2-year follow-up after unilateral CI in bilaterally deafened patients. Our results for speech perception and HRQoL showed a significant improvement during the 6-month follow-up that remained stable thereafter during a 24-month follow-up, even after finishing the hearing rehabilitation program.
|Age-Dependent Psychological Factors Influencing the Outcome of Cochlear Implantation in Elderly Patients|
Introduction: Increasing number of older adults undergo cochlear implantation (CI). Accumulating evidence implicates that the outcome of implantation may not only depend on physical and psychological health status of patients but also on their age. In the present work, we analyzed the elderly (70–80) and very old (80+) patients who underwent CI regarding their hearing abilities, health-related quality of life (HRQoL), and psychological comorbidities. Patients and Methods: Eighty-six patients were included in this prospective study. The patients were split into two groups: 70–80 years-old (n = 62) and ≥ 80 years-old (n = 24). Hearing performance was assessed with Freiburg monosyllabic test and Oldenburg inventory (OI); the health-related quality of life was measured with Nijmegen Cochlear Implantation Questionnaire (NCIQ); depressive symptoms with General Depression Scale (ADS-L); stress with Perceived Stress Questionnaire (PSQ) and anxiety with General Anxiety Disorder-7 (GAD-7). Results: Prior to CI, the hearing performance (Ol) impacted positively the HRQoL of both groups whereas the perceived stress (PSQ) had a negative impact. Six months after implantation, the HRQoL of 70–80 group was still positively influenced by the hearing performance (Ol) whereas HRQoL of 80+ group was influenced by stress perception (negative impact) and anxiety (positive impact). Twelve months later, anxiety and depressive symptoms correlated negatively with HRQoL of both age groups. Hearing performance had the positive and anxiety the negative impact on HRQoL in both groups but in addition, the 80+ group seemed to benefit from an increased level of anxious symptoms. Conclusion: In elderly patients, the outcome of CI depends on their psychological status. Differences found between the age groups imply a need for an age-group targeted psychological counselling, which might further improve outcome of CI.
|Pediatric Bilateral Cochlear Implantation: Simultaneous Versus Sequential Surgery|
Objective: To compare outcomes of bilateral cochlear implantation between simultaneous and sequential surgeries. Study Design: Retrospective study of surgical outcome for 54 children who received bilateral cochlear implants (CIs) over a five-year period. Setting: Tertiary health care Patients: We analyze surgical outcomes for 54 children who received two CIs over a five-year period. Thirty-two of these children received these implants simultaneously and 22 of these children received their implants sequentially (76 CI operations and 108 CI). Intervention: One hundred and eight CIs; Group A—bilateral simultaneous CI; Group B— bilateral sequential CI. Main Outcome Measures: Measurement of body temperature; recording drug administration measurement of the total length of hospital stay, surgery time, and total operating room utilization; recording complications. Results: Simultaneous bilateral CI-implantation is associated with a significantly reduced cumulative surgical time and cumulative operating room time. It shortens the total in-patient stay for children in comparison to sequential implantations. There were no clinically significant, adverse consequences of simultaneous implant surgery. Further information include medical history including cochlear malformations as well as complications after the surgery, use of analgesic and antiemetic medication and length of hospital stay. Conclusions: Simultaneous bilateral surgery is a safe option of pediatric cochlear implantation.
|Cochlear Implantation in Patients With Single-sided Deafness After the Translabyrinthine Resection of the Vestibular Schwannoma—Presented at the Annual Meeting of ADANO 2016 in Berlin|
Objective: To evaluate effectiveness of the cochlear implant (CI) to facilitate single-sided deafness (SSD) rehabilitation following translabyrinthine resection of the vestibular schwannoma. Study Design: Retrospective patient review. Setting: Single center, University hospital. Patients: Patients with SSD who underwent translabyrinthine resection of a vestibular schwannoma with anatomical preservation of the cochlear nerve and subsequent CI on the same ear. Interventions: CI at post-translabyrinthine resection of the acoustic neuroma to treat SSD, and evaluation by retrospective individual case review in a period from 2009 to 2016. Main Outcome Measures: Individual patients' clinical outcome and speech understanding. Results: Thirteen patients were provided CI. In all cases, complete removal of the tumor was achieved and the cochlear nerve was preserved; in one case, the CI was implanted simultaneously. In most cases, the follow-up interval was 2 years. In 9 of 13 cases, the implanted ear achieved capability to understand and discriminate monosyllabic words at 65 dB. Level of speech understanding of over 50% at 65 dB was possible in 7 patients at 12 months after the first fitting of CI. Conclusions: Under certain conditions, CI was an effective solution to restore hearing in patients with SSD following translabyrinthine access to the skull base. Study with prospective design is required to provide more significant results.
|Association Between Stress and Tinnitus—New Aspects|
This contribution focuses on the relationship between stress and tinnitus. While the causal and directional pathways between these constructs continue to remain unclear, this paper uses an allostasis-based framework to discuss associations between physiological stress responses, individuals' idiosyncratic experiences of the tinnitus percept, and psychological treatment approaches.
|How Do We Know That Our Patients Have Benefitted From Our ENT/Audiological Interventions? Presented at the Annual Meeting of ADANO 2016 in Berlin|
This short review article gives an introduction to some of the fundamental concepts and challenges facing measurement in hearing healthcare practice and research. The impact of hearing loss almost always extends beyond the sensory impairment itself, even when the measured degree of audiometric loss is mild. Yet, going beyond audibility, into the realm of measuring impact, takes us into a much more complex and less well-defined space. How does one therefore best measure the therapeutic benefit for evaluating efficacy or for clinical practice audit? Three case studies illustrate approaches to overcome such challenges. Each example highlights the importance of thinking critically about what it is one is seeking trying to measure, rather than selecting a questionnaire instrument based simply on its popularity or accessibility. We conclude by highlighting the important role that clinicians can play in collecting clinical data about their preferred instruments so that we have some evidence to inform decisions about good practice (content validity etc.). We would also strongly support open data sharing as we think that this is one of the best ways to make the most rapid progress the field.
Παρασκευή, 17 Μαΐου 2019
Otology & Neurotology - Papers Presented at the Annual Meeting of the German Audiology and Neurotology Group 2016 (ADANO) in Berlin
Otology & Neurotology - Highlights from the ACIA 15th Symposium on Cochlear Implants in Children in San Francisco
|Introduction to the Special Issue: 15th Symposium on Cochlear Implants in Children|
No abstract available
|Relationship Between Objective and Behavioral Audiology for Young Children Being Assessed for Cochlear Implantation: Implications for CI Candidacy Assessment|
Objective: This study aimed to evaluate the feasibility of making cochlear implant recommendations based on diagnostic ABR and ASSR results. The goal was to challenge the need for behavioral audiometry as part of the standard cochlear implant assessment battery for infants with profound hearing loss and to reduce the age at which cochlear implant recommendation was made. Study Design: A retrospective review of 123 patient files for children referred to the pediatric cochlear implant service before 3 years of age over a 3-year period was undertaken. Results for click-ABR, ASSR, and behavioral audiology at 500, 1k, 2k and 4k Hz, and tympanometry were collected and relationships were investigated for 64 children who met the inclusion criteria. Data were excluded for 59 children due to the presence of auditory neuropathy findings, middle ear pathology at the time of testing, if ASSR was not assessed at intensity levels >85 dB, and/or behavioral testing was judged to be unreliable by two experienced clinicians. Setting: Primary care pediatric cochlear implant program located within a hospital setting. Patients: Pediatric patients referred for cochlear implant evaluation before 3 years of age. Interventions(s): Children were assessed using ABR, ASSR, and behavioral audiometry for identification and confirmation of hearing loss. Main Outcome Measures(s): Correlation between diagnostic click-ABR and ASSR thresholds and subsequently obtained behavioral hearing thresholds. Results: Results for objective measures (click-ABR and ASSR) were significantly correlated with behavioral results. The correlations, however, were poorer than expected with limited predictive value. For 6 of the 64 children click-ABR and/or ASSR suggested profound hearing loss and corresponding behavioral hearing threshold was found to be in the severe hearing loss range. Conclusions: Findings of this study do not support making cochlear implant recommendations based on the findings of diagnostic click-ABR and ASSR alone. Investigating ways to reduce the average age children with severe-to-profound hearing loss receive a cochlear implant is a priority for the study institution. An alternate evaluation pathway for infants which incorporates a multifaceted assessment is warranted and will be the focus of future work at the study institution.
|Remote Programming of Cochlear Implants|
Objective: This study investigated the safety and efficacy of remote programming of cochlear implants. Study Design: Single-subject design Setting: Four North American clinical sites Patients: Forty cochlear implant recipients aged 12 years or older Intervention: Subjects had their cochlear implants programmed at a location that was remote from their audiologist using telecommunication with and without the support of a facilitator. Main Outcome Measures: Consonant-Nucleus-Consonant (CNC) word scores and the Speech, Spatial, and Qualities of Hearing Scale-C (SSQ-C) were compared using the subject's in-office MAP (program) and MAPs programmed remotely with and without the assistance of a facilitator. Additional subjective preference data were gathered from subjects and audiologists via questionnaires. Results: MAPs programmed via the three different models did not yield significantly different group mean CNC word scores. No device/procedure-related adverse events occurred. SSQ-C questionnaire results indicated that recipients received similar subjective benefit from familiar in-office, remote-facilitated, and remote-unassisted MAPs. Conclusions: Remote programming is an effective means of cochlear implant service delivery. The practice was approved by the FDA on November 17, 2017 supported by the results of this study.
|Bilateral Cochlear Implants Using Two Electrode Lengths in Infants With Profound Deafness|
Objective: The goal of this investigation was to determine if a short electrode in one ear and standard electrode in the contralateral ear could be an option for infants with congenital profound deafness to theoretically preserve the structures of the inner ear. Similarities in performance between ears and compared with a control group of infants implanted with bilateral standard electrodes was evaluated. Study Design: Repeated-measure, single-subject experiment. Setting: University of Iowa—Department of Otolaryngology. Participants: Nine infants with congenital profound bilateral sensorineural hearing loss. Intervention(s): Short and standard implants. Main Outcome Measure(s): Early speech perception test (ESP), children's vowel, phonetically balanced-kindergarten (PB-K) word test, and preschool language scales-3 (PLS-3). Results: ESP scores showed performance reaching a ceiling effect for the individual short and standard ears and bilaterally. The children's vowel and PB-K word results indicated significant (both p < 0.001) differences between the two ears. Bilateral comparisons to age-matched children with standard bilateral electrodes showed no significant differences (p = 0.321) in performance. Global language performance for six children demonstrated standard scores around 1 standard deviation (SD) of the mean. Two children showed scores below the mean, but can be attributed to inconsistent device usage. Averaged total language scores between groups showed no difference in performance (p = 0.293). Conclusions: The combined use of a short electrode and standard electrode might provide an option for implantation with the goal of preserving the cochlear anatomy. However, further studies are needed to understand why some children have or do not have symmetric performance.
|Hearing Preservation in Pediatric Recipients of Cochlear Implants|
Objective: To determine factors that influence low-frequency hearing preservation following pediatric cochlear implantation and compare hearing preservation outcomes between 20 and 24 mm depth lateral wall electrodes. Study Design: Retrospective chart review. Setting: Tertiary academic referral center. Patients: Pediatric cochlear implant recipients (under the age of 18) who presented preoperatively with a low-frequency pure tone average (LFPTA; 125, 250 and 500 Hz) ≤ 70 dB HL. Intervention: Cochlear implantation Main Outcome Measures: Multiple logistic regression evaluating the influence of variables on change in LFPTA including preoperative low-frequency hearing, lateral wall or perimodiolar electrode, progressive vs stable hearing, side, time from surgery, and the presence or the absence of enlarged vestibular aqueduct. A second analysis reviews the 12-month postactivation hearing preservation of a subset of subjects implanted with modern lateral wall electrodes. Results: A total of 105 subjects were included from the last 10 years for our multiple logistic regression analysis. This demonstrated a significant correlation of poorer preoperative low-frequency hearing with change in LFPTA. A significant negative effect of electrode type, specifically perimodiolar electrodes was also seen. Forty-five subjects from the last 3 years undergoing cochlear implantation with a lateral wall electrode demonstrated an overall 12-month preservation rate (LFPTA < 90 dB) of 82%. Differences in preservation rates existed between different electrodes. Conclusion: Preservation of low-frequency hearing following cochlear implantation is predicted both by preoperative low-frequency hearing as well as type of electrode implanted. Consistent low-frequency hearing preservation is possible in pediatric subjects receiving lateral wall electrodes, although differences exist between electrode types.
|Hybrid Music Perception Outcomes: Implications for Melody and Timbre Recognition in Cochlear Implant Recipients|
Objective: To examine whether or not electric–acoustic music perception outcomes, observed in a recent Hybrid L24 clinical trial, were related to the availability of low-frequency acoustic cues not present in the electric domain. Study Design: Prospective, repeated-measures, within-subject design. Setting: Academic research hospital. Subjects: Nine normally hearing individuals. Intervention: Simulated electric–acoustic hearing in normally hearing individuals. Main Outcomes Measures: Acutely measured melody and timbre recognition scores from the University of Washington Clinical Assessment of Music Perception (CAMP) test. Results: Melody recognition scores were consistently better for listening conditions that included low-frequency acoustic information. Mean scores for both acoustic (73.5%, S.D. = 15.5%) and electric–acoustic (67.9%, S.D. = 21.2%) conditions were significantly better (p < 0.001) than electric alone (39.2%, S.D. = 18.1%). This was not the case for timbre recognition for which scores were more variable across simulated listening modes with no significant differences found in mean scores across electric (36.1%, S.D. = 17.7%), acoustic (38.0%, S.D. = 20.4%), and electric–acoustic (40.7%, S.D. = 19.7%) conditions (p > 0.05). Conclusion: Recipients of hybrid cochlear implants demonstrate music perception abilities superior to those observed in traditional cochlear implant recipients. Results from the present study support the notion that electric–acoustic stimulation confers advantages related to the availability of low-frequency acoustic hearing, most particularly for melody recognition. However, timbre recognition remains more limited for both hybrid and traditional cochlear implant users. Opportunities remain for new coding strategies to improve timbre perception.
|Beyond Technology: The Interaction of Perceptual Accuracy and Experiential Factors in Pediatric Music Engagement|
Background: Music engagement (the active making of music, e.g., music lessons and ensembles) is a common part of educational and community experiences. Music making typically involves listening to and production of rapidly changing combinations of pitch, timbre, and rhythm, which can be challenging for cochlear implant (CI) recipients, given that pitch and timbre are poorly conveyed through the CI. Pediatric CI users have variable patterns of music engagement, but some have achieved, sustained participation despite the degraded CI signal. What factors contribute to their persistence in these demanding listening situations? Our study examined a cohort of pediatric CI recipients from our center to better understand those perceptual and experiential factors most influential in relation to music engagement. Method: Regressions and correlations were run for measures of pitch and speech perception, hearing history, familial involvement in music, personal importance of music, and extent of music engagement (years in music lessons; general involvement in music). Results: Pitch ranking accuracy was a significant predictor of sustained participation in music lessons (p = 0.0019), and sustained involvement in music (p = 0.0038), as well as performance on CNC words (p = −0.0060) and phonemes (p = −0.0174). Extent of familial involvement in music at the time of testing was significantly predictive of the user's musical engagement (p = 0.0007). Personal importance of music was not predicted by or significantly correlated with, any of the variables investigated. Conclusion: Better pitch perception was associated with sustained involvement in music lessons as well as better speech perception. However, familial involvement in music was of greater impact for sustained music engagement. Judicious choice of musical instrument also influenced persistence. The positive impact of familial involvement indicates that perceptual limitations associated with CI processing do not present insurmountable barriers to music engagement. Because music engagement provides normalizing social involvement and challenging auditory practice, the impact of parental involvement has implications for counseling parents of CI users.
|Comparison of Skull Radiograph and Computed Tomography Measurements of Cochlear Implant Insertion Angles|
Background: Measurement of the angular depth of insertion (aDOI) of cochlear implant electrode arrays has numerous clinical and research applications. Plain-film radiographs are easily obtained intraoperatively and have been described as a means to calculate aDOI. CT imaging with 3D reformatting can also be used for this measurement, but is less conveniently obtained and requires higher radiation doses, a particular concern in pediatrics. The extent to which plain-film and 3D CT image-based measurements are representative of the true position of the electrode within the cochlea is unknown. Methods: Cochlear implantation was performed on 10 cadaveric temporal bones. Five bones were implanted with perimodiolar electrodes (Contour Advance TM, Cochlear, Sydney, Australia) and five were implanted with lateral wall electrodes (Slim Straight, Cochlear). The insertion depths of the electrodes were varied. Each bone was imaged with a radiograph and CT. aDOI was measured for each bone in each imaging modality by a neurotologist and a neuroradiologist. To obtain a "gold standard" estimate of aDOI, the implanted temporal bones were embedded in an epoxy resin and methodically sectioned at 100 μm intervals; histologic images were captured at each interval. A 3D stack of the images was compounded, and a MATLAB script used to calculate aDOI of the most apical electrode. Measurements in the three modalities (radiograph, CT, and histology) were then compared. Results: The average aDOI across all bones was similar for all modalities: 423° for radiographs, 425° for CT scans, and 427° for histology, indicating that neither imaging modality resulted in large systematic errors. Using the histology-measured angles as a reference, the average error for CT-based measures (regardless of whether the error was in the positive or negative direction) was 12°, and that for radiograph-based measures was 15°. This small difference (12 vs 15° error) was not statistically significant. Conclusion: Based on this cadaveric temporal bone model, both radiographs and CTs can provide reasonably accurate aDOI measurements. In this small sample, and as expected, the CT-based estimates were more accurate than the radiograph-based measurements. However, the difference was small and not statistically significant. Thus, the use of plain radiographs to calculate aDOI seems judicious whenever it is desired to prevent unnecessary radiation exposure and expense.
|Surgical Experience and Early Outcomes With a Slim Perimodiolar Electrode|
Introduction: In 2016 the Cochlear CI532 received FDA approval and has since been the primary full-length electrode from this manufacturer implanted at our center. Our experience to date including surgical technique and early patient outcomes are reviewed here. Methods: Since 2016, this array was used as our standard full length Cochlear array, including children with normal anatomy, with 237 total implantations. Surgical experience and clinical outcomes including low frequency hearing preservation and speech perception on CNC words were analyzed in those with at least 6 months follow-up implanted through June 2017 (n = 94). Results: Speech perception scores are improving over clinical follow-up in accord with other electrode arrays. Hearing preservation is possible with a number of patients utilizing acoustic low frequency hearing in conjunction with electric stimulation from their CI. Tip fold overs were infrequent (4.6%) and always identified on intraoperative x-ray. No patients left the operating room with a tip fold over. Conclusions: Speech perception outcomes with the CI532 slim periomodiolar array are similar to other full length arrays with the added potential for at least short term preservation of residual acoustic hearing. There is a learning curve to its use and intraoperative x-rays are valuable to ensure optimal placement.
|Temporal Modulation Detection in Children and Adults With Cochlear Implants: Initial Results|
Objectives: The auditory experience of early deafened pediatric cochlear implant (CI) users is different from that of postlingually deafened adult CI users due to disparities in the developing auditory system. It is therefore expected that the auditory psychophysical capabilities between these two groups would differ. In this study, temporal resolving ability was investigated using a temporal modulation detection task to compare the performance outcomes between these two groups. Design: The minimum detectable modulation depth of amplitude modulated broadband noise at 100 Hz was measured for 11 early deafened children with a CI and 16 postlingually deafened adult CI users. Results: Amplitude modulation detection thresholds were significantly lower (i.e., better) for the pediatric CI users than for the adult CI users. Within each group, modulation detection thresholds were not significantly associated with chronologic age, age at implantation, or years of CI experience. Conclusions: Early implanted children whose auditory systems develop in response to electric stimulation demonstrate better temporal resolving abilities than postlingually deafened adult CI users. This finding provides evidence to suggest that early implanted children might benefit from sound coding strategies emphasizing temporal information.
Otology & Neurotology - Papers Presented at the Annual Meeting of the German Audiology and Neurotology Group 2015 (ADANO) in Bern
|Ocular Vestibular Evoked Myogenic Potentials: Where Are We Now?|
Objective: Over the last decade, ocular vestibular evoked myogenic potentials (oVEMPs) have evolved as a new clinical test for dynamic otolith (predominantly utricular) function. The aim of this review is to give an update on the neurophysiological foundations of oVEMPs and their implications for recording and interpreting oVEMP responses in clinical practice. Conclusion: Different lines of anatomical, neurophysiological, and clinical evidence support the notion that oVEMPs measure predominantly contralateral utricular function, while cervical cVEMPs are an indicator of ipsilateral saccular function. Bone-conducted vibration (BCV) in the midline of the forehead at the hairline (Fz) or unilateral air-conducted sound (ACS) are commonly used as stimuli for oVEMPs. It is recommended to apply short stimuli with short rise times for obtaining optimal oVEMP responses. Finally, this review summarizes the clinical application and interpretation of oVEMPs, particularly for vestibular neuritis, Ménière's disease, superior canal dehiscence and "challenging" patients.
|The Role of Auditory Evoked Potentials in the Context of Cochlear Implant Provision|
Auditory evoked potentials (AEP) are highly demanded during the whole process of equipping patients with cochlear implants (CI). They play an essential role in preoperative diagnostics, intraoperative testing, and postoperative monitoring of auditory performance and success. The versatility of AEP's is essentially enhanced by their property to be evokable by acoustic as well as electric stimuli. Thus, the electric responses of the auditory system following acoustic stimulation and recorded by the conventional surface technique as well as by transtympanic derivation from the promontory (Electrocochleography [ECochG]) are used for the quantitative determination of hearing loss and, additionally, electrically evoked compound actions potentials (ECAP) can be recorded with the intracochlear electrodes of the implant just adjacent to the stimulation electrode to check the functional integrity of the device and its coupling to the auditory system. The profile of ECAP thresholds is used as basis for speech processor fitting, the spread of excitation (SOE) allows the identification of electrode mislocations such as array foldover, and recovery functions may serve to optimize stimulus pulse rate. These techniques as well as those relying on scalp surface activity originating in the brainstem or the auditory cortex accompany the CI recipient during its whole life span and they offer valuable insights into functioning and possible adverse effects of the CI for clinical and scientific purposes.
|The Effect of Peripheral Vestibular Recovery on Improvements in Vestibulo-ocular Reflexes and Balance Control After Acute Unilateral Peripheral Vestibular Loss|
Background: Patients with an acute unilateral peripheral vestibular deficit (aUPVD), presumed to be caused by vestibular neuritis, show asymmetrical vestibular ocular reflexes (VORs) that improve over time. Questions arise regarding how much of the VOR improvement is due to peripheral recovery or central compensation, and whether differences in peripheral recovery influence balance control outcomes. Methods: Thirty patients were examined at aUPVD onset and 3, 6, and 13 weeks later with four different VOR tests: caloric tests; rotating (ROT) chair tests performed in yaw with angular accelerations of 5 and 20 degrees/s2; and video head impulse tests (vHIT) in the yaw plane. ROT and vHIT responses and balance control of 11 patients who had a caloric canal paresis (CP) more than 90% at aUPVD onset and no CP recovery (no-CPR) at 13 weeks in caloric tests were compared with those of 19 patients with CP recovery (CPR) to less than 30%, on average. Balance control was measured with a gyroscope system (SwayStar) recording trunk sway during stance and gait tasks. Results: ROT and vHIT asymmetries of no-CPR and CPR patients reduced over time. The reduction was less at 13 weeks (36.2% vs. 83.5% on average) for the no-CPR patients. The no-CPR group asymmetries at 13 weeks were greater than those of CPR patients who had normal asymmetries. The greater asymmetries were caused by weaker deficit side responses which remained deficient in no-CPR patients at 13 weeks. Contra-deficit side vHIT and ROT responses remained normal. For all balance tests, sway was slightly greater for no-CPR compared with CPR patients at aUPVD onset and 3 weeks later. At 13 weeks, only sway during walking eyes closed was greater for the no-CPR group. A combination of 5 degrees/s2 ROT and balance tests could predict at onset (90% accuracy) which patients would have no-CPR at 13 weeks. Conclusions: These results indicate that for ROT and vHIT tests, central compensation is observed in CPR and no-CPR patients. It acts primarily by increasing deficit side responses. Central compensation provides approximately 60% of the VOR improvement for CPR patients. The rest of the improvement is due to peripheral recovery which appears necessary to reduce VOR asymmetry to normal at 13 weeks on average. Balance control improvement is more rapid than that of the VOR and marginally affected by the lack of peripheral recovery. Both VOR and balance control measures at onset provide indicators of future peripheral recovery. For these reasons VOR and balance control needs to be tested at aUPVD onset and at 13 weeks.
|Menière and Friends: Imaging and Classification of Hydropic Ear Disease|
Background: Over 75 years ago, endolymphatic hydrops was discovered as the pathologic correlate of Menière's disease. However, this pathologic finding could be ascertained only in postmortem histologic studies. Due to this diagnostic dilemma and the variable manifestation of the various audiovestibular symptoms, diagnostic classification systems based on clinical findings have been used hitherto. Methods: A review of the literature of magnetic resonance (MR) imaging of hydropic ear disease. Results: Recent developments of high resolution MR imaging of the inner ear have now enabled us to visualize in vivo endolymphatic hydrops in patients with suspected Menière's disease. The existing knowledge from temporal bone histologic studies and from the emerging evidence on imaging based evaluation of patients with suspected Menière's disease indicate that endolymphatic hydrops not only is responsible for the full-blown clinical triad of simultaneous attacks of auditory and vestibular dysfunction, but also for other clinical presentations such as "vestibular" and "cochlear Menière's disease." Conclusion: As a consequence, we propose the term "Hydropic Ear Disease" as a new terminology which is based on symptomatic and imaging characteristics of these clinical entities to clarify and simplify their diagnostic classification.
|Cochlear Pericytes Are Capable of Reversibly Decreasing Capillary Diameter In Vivo After Tumor Necrosis Factor Exposure|
Objective: The aim of this work was to evaluate the effect of tumor necrosis factor (TNF) and its neutralization with etanercept on the capability of cochlear pericytes to alter capillary diameter in the stria vascularis. Methods: Twelve Dunkin–Hartley guinea pigs were randomly assigned to one of three groups. Each group was treated either with placebo and then placebo, TNF and then placebo, or TNF and then etanercept. Cochlear pericytes were visualized using diaminofluorescein-2-diacetate and intravasal blood flow by fluorescein-dextrane. Vessel diameter at sites of pericyte somas and downstream controls were quantified by specialized software. Values were obtained before treatment, after first treatment with tumor necrosis factor or placebo and after second treatment with etanercept or placebo. Results: Overall, 199 pericytes in 12 animals were visualized. After initial treatment with TNF, a significant decrease in vessel diameter at sites of pericyte somas (3.6 ±4.3%, n = 141) compared with placebo and downstream controls was observed. After initial treatment with TNF, the application of etanercept caused a significant increase (3.3 ±5.5%, n = 59) in vessel diameter at the sites of pericyte somata compared with placebo and downstream controls. Conclusion: We have been able to show that cochlear pericytes are capable of reducing capillary diameter after exposition to TNF. Moreover, the reduction in capillary diameter observed after the application of TNF is revertible after neutralization of tumor necrosis factor by the application of etanercept. It seems that contraction of cochlear pericytes contributes to the regulation of cochlear blood flow.
|Effectiveness of Directional Microphones in Bilateral/Bimodal Cochlear Implant Users—Impact of Spatial and Temporal Noise Characteristics|
Objective: To measure speech reception thresholds (SRTs) in co-located (S0N0) and diffuse noise conditions (multi-source noise field, MSNF) and to assess the impact of beamforming algorithms in MSNF in cochlear implant (CI) users. Study Design: Non-randomized, open, prospective study. Setting: Tertiary referral cochlear implantation center. Patients: Participants included 14 CI users (7 bimodal, 7 bilateral) and 14 normal hearing young adults. Interventions: Cochlear implantation. Main Outcome Measures: SRTs were assessed by means of a German matrix sentence test in either continuous or modulated noise. Loudspeakers were configured in two different conditions: S0N0 and MSNF (speech source in front, four speakers distributed at ±28.6 and ±151.4 degrees). In MSNF, the CI speech processor microphone was set in different directional sensitivity settings: standard (sub-cardioid), fixed (super-cardioid), and adaptive. Results: In continuous noise, SRTs of both CI groups were comparable. In modulated noise, bimodal CI users showed lower SRTs than bilateral CI group, but significant benefit from glimpsing was only demonstrated in normal hearing participants. All subject groups showed significant spatial release from masking (i.e., SRT improvement in MSNF compared with S0N0 condition) in continuous noise. A tendency of improved SRT (1 dB bimodal, 2 dB bilateral) with fixed and adaptive directional sensitivity was found which could not be statistically confirmed due to large between-subject variations. Conclusions: The absence of the glimpsing effect in CI users was reaffirmed in the present study. Although very effective in single noise source conditions, the beneficial impact of beamforming algorithms in multiple noise source conditions is poor.
|Evaluation of Cochlear Implant Receiver Position and Its Temporal Changes|
Hypothesis: It was the aim of this study to establish normative data regarding intended changes in cochlear implants (CI) receiver positioning by one surgeon over time. Background: With the increasing number of CI patients, the probability of needing magnetic resonance imaging (MRI) increases. The accessibility of cerebral structures is limited by MRI artifacts caused by CI. New studies show a dependence of the visibility of intracranial structures by the MRI sequences and the position of the CI receiver itself. Methods: Retrospective and interindividual investigation of topograms with regard to the nasion–external auditory canal–internal magnet angle and the distance between the internal magnet and the external auditory canal. We evaluated scans of 150 CI recipients implanted from 2008 until 2015. Results: The most common implant position in the years 2008 to 2015 was a nasion–external auditory canal–internal magnet angle between 121 and 140 degrees (mean, 127 degrees) and an internal magnet–external auditory canal distance between 61 and 80 mm (mean, 70 mm). Over time the nasion–external auditory canal–internal magnet angle increased and the internal magnet–external auditory canal distance decreased, both to a statistically significant degree. A difference between the manufacturers was not observed. Conclusion: The CI receiver position is important for an artifact-free examination of the internal auditory canal and the cochlea. The realization of the position over a time course supports awareness of artifact-related visibility limitations.
|Single-Sided Deafness: Impact of Cochlear Implantation on Speech Perception in Complex Noise and on Auditory Localization Accuracy|
Objective: To assess auditory localization accuracy and speech reception threshold (SRT) in complex noise conditions in adult patients with acquired single-sided deafness, after intervention with a cochlear implant (CI) in the deaf ear. Study Design: Nonrandomized, open, prospective patient series. Setting: Tertiary referral university hospital. Patients: Eleven patients with late-onset single-sided deafness (SSD) and normal hearing in the unaffected ear, who received a CI. All patients were experienced CI users. Intervention: Unilateral cochlear implantation. Main Outcome Measures: Speech perception was tested in a complex multitalker equivalent noise field consisting of multiple sound sources. Speech reception thresholds in noise were determined in aided (with CI) and unaided conditions. Localization accuracy was assessed in complete darkness. Acoustic stimuli were radiated by multiple loudspeakers distributed in the frontal horizontal plane between −60 and +60 degrees. Results: In the aided condition, results show slightly improved speech reception scores compared with the unaided condition in most of the patients. For 8 of the 11 subjects, SRT was improved between 0.37 and 1.70 dB. Three of the 11 subjects showed deteriorations between 1.22 and 3.24 dB SRT. Median localization error decreased significantly by 12.9 degrees compared with the unaided condition. Conclusion: CI in single-sided deafness is an effective treatment to improve the auditory localization accuracy. Speech reception in complex noise conditions is improved to a lesser extent in 73% of the participating CI SSD patients. However, the absence of true binaural interaction effects (summation, squelch) impedes further improvements. The development of speech processing strategies that respect binaural interaction seems to be mandatory to advance speech perception in demanding listening situations in SSD patients.
|Cochlear Implantation in Children With Congenital Unilateral Deafness: A Case Series|
Objectives: Cochlear implant is regarded as a treatment option for hearing rehabilitation of adults with unilateral sensorineural hearing loss. A clear benefit has been experienced in regard to speech comprehension in noise, localization, and quality of life. The aim of this study was to investigate the benefit of cochlear implantation for children with congenital unilateral hearing loss. Study Design: Retrospective case series. Setting: Tertiary referral center; cochlear implant program. Patients: Ten children with congenital unilateral hearing loss. Intervention: After extensive consultation with the families and intensive counseling, the children received a cochlear implant. Main Outcome Measures: Categories of auditory performance, speech discrimination in open set, subjective assessment by Speech, Spatial and Qualities scale questionnaire. Conclusion: Eight of ten children use their cochlear implant consistently on a daily basis. Two children who were equipped with an implanted device at a later age tend to nonuse of the device. The evaluation of binaural hearing in small children is still difficult and methods have to be developed to allow objective assessment.
Otology & Neurotology - ACIA: Highlights from the 14th International Symposium on Cochlear Implants, Toronto, Canada
|Introduction to the 14th International Symposium on Cochlear Implants and other Implantable Auditory Technologies, Toronto, Canada, May 11 to 14, 2016|
No abstract available
|Physiological Mechanisms in Combined Electric–Acoustic Stimulation|
Objective: Electrical stimulation is normally performed on ears that have no hearing function, i.e., lack functional hair cells. The properties of electrically-evoked responses in these cochleae were investigated in several previous studies. Recent clinical developments have introduced cochlear implantation (CI) in residually-hearing ears to improve speech understanding in noise. The present study documents the known physiological differences between electrical stimulation of hair cells and of spiral ganglion cells, respectively, and reviews the mechanisms of combined electric and acoustic stimulation in the hearing ears. Data Sources: Literature review from 1971 to 2016. Conclusions: Compared with pure electrical stimulation the combined electroacoustic stimulation provides additional low-frequency information and expands the dynamic range of the input. Physiological studies document a weaker synchronization of the evoked activity in electrically stimulated hearing ears compared with deaf ears that reduces the hypersynchronization of electrically-evoked activity. The findings suggest the possibility of balancing the information provided by acoustic and electric input using stimulus intensity. Absence of distorting acoustic–electric interactions allows exploiting these clinical benefits of electroacoustic stimulation.
|NANOCI—Nanotechnology Based Cochlear Implant With Gapless Interface to Auditory Neurons|
Cochlear implants (CI) restore functional hearing in the majority of deaf patients. Despite the tremendous success of these devices, some limitations remain. The bottleneck for optimal electrical stimulation with CI is caused by the anatomical gap between the electrode array and the auditory neurons in the inner ear. As a consequence, current devices are limited through 1) low frequency resolution, hence sub-optimal sound quality and 2), large stimulation currents, hence high energy consumption (responsible for significant battery costs and for impeding the development of fully implantable systems). A recently completed, multinational and interdisciplinary project called NANOCI aimed at overcoming current limitations by creating a gapless interface between auditory nerve fibers and the cochlear implant electrode array. This ambitious goal was achieved in vivo by neurotrophin-induced attraction of neurites through an intracochlear gel-nanomatrix onto a modified nanoCI electrode array located in the scala tympani of deafened guinea pigs. Functionally, the gapless interface led to lower stimulation thresholds and a larger dynamic range in vivo, and to reduced stimulation energy requirement (up to fivefold) in an in vitro model using auditory neurons cultured on multi-electrode arrays. In conclusion, the NANOCI project yielded proof of concept that a gapless interface between auditory neurons and cochlear implant electrode arrays is feasible. These findings may be of relevance for the development of future CI systems with better sound quality and performance and lower energy consumption. The present overview/review paper summarizes the NANOCI project history and highlights achievements of the individual work packages.
|Cochlear Implants Meet Regenerative Biology: State of the Science and Future Research Directions|
The cochlear implant, the first device to restore a human sense, is an electronic substitute for lost mechanosensory hair cells. It has been successful at providing hearing to people with severe to profound hearing loss and as of 2012, an estimated 324,000 patients worldwide have received cochlear implants. Users of cochlear implants however, suffer from difficulties in processing complex sounds such as music and in discriminating sounds in noisy environments. Recent advances in regenerative biology and medicine are opening new avenues for enhancing the efficacy of cochlear implants by improving the neural interface in the future and offer the possibility of an entirely biological solution for hearing loss in the long term. This report comprises the latest developments presented in the first Symposium on cochlear implants and regenerative biology, held at the 14th International Conference on Cochlear Implants in 2016 in Toronto, Canada.
|Linking Deafness and Dementia: Challenges and Opportunities|
The rising incidence of dementia locally and worldwide has now reached a critical level. The associated costs associated with these individuals will ultimately be untenable to most societies. Furthermore there is a paucity of highly effective treatments. However, the recent discovery of the association of hearing loss and dementia may open many potential opportunities. Although we still are acquiring knowledge on the pathophysiology of this association, clinicians are hopeful that our current highly effective treatments of hearing loss may ultimately be shown to have a positive effect on those with dementia.
|What Does Music Sound Like for a Cochlear Implant User?|
Objective: Cochlear implant research and product development over the past 40 years have been heavily focused on speech comprehension with little emphasis on music listening and enjoyment. The relatively little understanding of how music sounds in a cochlear implant user stands in stark contrast to the overall degree of importance the public places on music and quality of life. The purpose of this article is to describe what music sounds like to cochlear implant users, using a combination of existing research studies and listener descriptions. We examined the published literature on music perception in cochlear implant users, particularly postlingual cochlear implant users, with an emphasis on the primary elements of music and recorded music. Additionally, we administered an informal survey to cochlear implant users to gather first-hand descriptions of music listening experience and satisfaction from the cochlear implant population. Conclusion: Limitations in cochlear implant technology lead to a music listening experience that is significantly distorted compared with that of normal hearing listeners. On the basis of many studies and sources, we describe how music is frequently perceived as out-of-tune, dissonant, indistinct, emotionless, and weak in bass frequencies, especially for postlingual cochlear implant users—which may in part explain why music enjoyment and participation levels are lower after implantation. Additionally, cochlear implant users report difficulty in specific musical contexts based on factors including but not limited to genre, presence of lyrics, timbres (woodwinds, brass, instrument families), and complexity of the perceived music. Future research and cochlear implant development should target these areas as parameters for improvement in cochlear implant-mediated music perception.
|Cochlear Implantation in Postlingual Adult Patients With Long-Term Auditory Deprivation|
Objective: The role of long-term hearing deprivation in cochlear implant performance is not well established, and the limits for implanting an auditory deprived ear are still unknown. The objective of this study was to evaluate the effect of long-term auditory deprivation time on cochlear implant results. Study Design: Retrospective case review study. Setting: Cochlear implantation tertiary referral center. Patients: Adult patients with postlingual deafness. Intervention: Unilateral cochlear implantation between 2001 and January 2015. Main Outcome Measures: Age at implantation, sex, etiology of hearing loss, and duration of auditory deprivation in the implanted ear were collected. Cochlear implants results were expressed in terms of vowel identification, disyllabic word recognition, and sentence recognition. Spearman's correlation test was applied to determine the relationship between auditory deprivation time and speech recognition scores. Additionally, patients were divided according to their auditory deprivation time before implantation in group A (less than 10 yr) and group B (more than 10 yr). Results: One hundred three patients met inclusion criteria for this study. There were 61 patients in group A, with a mean deprivation time of 2.52 years. There were 42 patients in group B, with a mean deprivation time of 19.67 years. There were no statistically significant differences between both groups regarding speech recognition scores. Deprivation time in the implanted ear was not statistically correlated with cochlear implantation performance. Conclusions: Long-term auditory deprivation in the ear to be implanted does not negatively influence cochlear implantation results and should not be considered criterion to reject cochlear implantation.
|A Smartphone Application for Customized Frequency Table Selection in Cochlear Implants|
Hypothesis: A novel smartphone-based software application can facilitate self-selection of frequency allocation tables (FAT) in postlingually deaf cochlear implant (CI) users. Background: CIs use FATs to represent the tonotopic organization of a normal cochlea. Current CI fitting methods typically use a standard FAT for all patients regardless of individual differences in cochlear size and electrode location. In postlingually deaf patients, different amounts of mismatch can result between the frequency-place function they experienced when they had normal hearing and the frequency-place function that results from the standard FAT. For some CI users, an alternative FAT may enhance sound quality or speech perception. Currently, no widely available tools exist to aid real-time selection of different FATs. This study aims to develop a new smartphone tool for this purpose and to evaluate speech perception and sound quality measures in a pilot study of CI subjects using this application. Methods: A smartphone application for a widely available mobile platform (iOS) was developed to serve as a preprocessor of auditory input to a clinical CI speech processor and enable interactive real-time selection of FATs. The application's output was validated by measuring electrodograms for various inputs. A pilot study was conducted in six CI subjects. Speech perception was evaluated using word recognition tests. Results: All subjects successfully used the portable application with their clinical speech processors to experience different FATs while listening to running speech. The users were all able to select one table that they judged provided the best sound quality. All subjects chose a FAT different from the standard FAT in their everyday clinical processor. Using the smartphone application, the mean consonant–nucleus–consonant score with the default FAT selection was 28.5% (SD 16.8) and 29.5% (SD 16.4) when using a self-selected FAT. Conclusion: A portable smartphone application enables CI users to self-select frequency allocation tables in real time. Even though the self-selected FATs that were deemed to have better sound quality were only tested acutely (i.e., without long-term experience with them), speech perception scores were not inferior to those obtained with the clinical FATs. This software application may be a valuable tool for improving future methods of CI fitting.
|Musical Rehabilitation in Adult Cochlear Implant Recipients With a Self-administered Software|
Objective: The goal of this study was to determine if a self-administered computer-based rehabilitation program could improve music appreciation and speech understanding in adults who have a cochlear implant (CI). Study Design: Prospective study. Setting: Tertiary adult CI program. Patients: Twenty-one postlingually deafened cochlear implant users between the ages of 27 and 79 years were recruited. Interventions(s): A self-administered music rehabilitative software was designed to help improve the perception of musical patterns of increasing complexity, as well as pitch and timbre perception, premised on focused and divided attention. All participants completed a diagnostic music test before and after rehabilitative training, including tests of pitch and timbre perception and pattern identification with increasing levels of difficulty. Speech data in quiet and noise was also collected both pre- and post-training. Participants trained for a minimum of 3.5 hours a week, for 4 weeks. Main Outcome Measure(s): Mean changes in music perception and enjoyment as well as speech perception (IEEE sentence test in quiet and noise). Results: Post-training diagnostic test scores, as compared with pretraining scores, indicated significant improvements in musical pattern perception. Tests of speech perception in quiet and in noise were significantly improved in a subset of this cohort. All of the training participants thought that the training helped to improve their recognition skills, and found the program to be beneficial. Conclusion: Despite the limitations of current CI technology, the results of this study suggest that auditory training can improve music perception skills, and possibly speech intelligibility, lending further support to rehabilitation being an integral part of the postimplantation paradigm.
|The Sound Quality of Cochlear Implants: Studies With Single-sided Deaf Patients|
Objective: The goal of the present study was to assess the sound quality of a cochlear implant for single-sided deaf (SSD) patients fit with a cochlear implant (CI). Background: One of the fundamental, unanswered questions in CI research is "what does an implant sound like?" Conventional CI patients must use the memory of a clean signal, often decades old, to judge the sound quality of their CIs. In contrast, SSD-CI patients can rate the similarity of a clean signal presented to the CI ear and candidate, CI-like signals presented to the ear with normal hearing. Methods: For Experiment 1 four types of stimuli were created for presentation to the normal hearing ear: noise vocoded signals, sine vocoded signals, frequency shifted, sine vocoded signals and band-pass filtered, natural speech signals. Listeners rated the similarity of these signals to unmodified signals sent to the CI on a scale of 0 to 10 with 10 being a complete match to the CI signal. For Experiment 2 multitrack signal mixing was used to create natural speech signals that varied along multiple dimensions. Results: In Experiment 1 for eight adult SSD-CI listeners, the best median similarity rating to the sound of the CI for noise vocoded signals was 1.9; for sine vocoded signals 2.9; for frequency upshifted signals, 1.9; and for band pass filtered signals, 5.5. In Experiment 2 for three young listeners, combinations of band pass filtering and spectral smearing lead to ratings of 10. Conclusion: The sound quality of noise and sine vocoders does not generally correspond to the sound quality of cochlear implants fit to SSD patients. Our preliminary conclusion is that natural speech signals that have been muffled to one degree or another by band pass filtering and/or spectral smearing provide a close, but incomplete, match to CI sound quality for some patients.
Otology & Neurotology - Papers Presented at the Annual Meeting of the German Audiology and Neurotology Group 2014 (ADANO) in Dresden
|Special Issue for Papers Presented at the Annual Meeting of the German Audiology and Neurootology Group 2014 (ADANO) in Dresden/Germany|
No abstract available
|What Could Posturography Tell Us About Balance Problems in Parkinson's Disease?|
Objective: Impaired balance in patients with Parkinson's disease (PD) leads to loss of balance and frequent falls. Computerized dynamic posturography allows the assessment of stance tasks whereas mobile posturography analyzes the balance in free-field conditions, where falls among PD patients commonly occur (e.g. sitting down or standing up). The aim of the present study is to assess postural stability in PD patients with both techniques. Study Design: Prospective study. Setting: University Hospitals, ambulatory care (outpatient clinic). Patients: Thirty-three patients diagnosed with idiopathic PD. Intervention: Balance assessment. Main Outcome Measures: Dizziness handicap inventory (DHI), activities-specific balance confidence scale (ABC), composite score of sensory organization test (SOT), results of free-field body sway analysis (standard balance deficit test (SBDT)), or geriatric SBDT. Results: PD patients showed a significantly higher sway in the roll direction in almost all of the SBDT conditions. Also, pathological sway compared with normative values was more prominent in complex tasks. There is a significant correlation between the different objective variables of the postural study (SOT and SBDT) and the ABC, but not with the DHI. Finally, the percentage of PD patients with a pathological score in SOT-composite score was 54.5% whereas in SBDT-composite score it was significantly higher (93.9%). Conclusion: Mobile posturography is more accurate in depicting the reality of balance impairment in PD patients than platform posturography. Also, ABC relates better than DHI to the significant psychological consequences of balance impairments. An increased lateral trunk sway seems to be a key factor of postural instability in PD patients.
|Functional Result After Cochlear Implantation in Children and Adults With Single-sided Deafness|
Background: Patients with single-sided deafness (SSD) suffer from reduced binaural hearing (i.e., sound localization and speech in noise discrimination). Cochlear implantation has recently been introduced for patients with SSD, as an alternative to hearing devices that employ contralateral routing of the signal. Application to children has also been started. Methods: We retrospectively analyze a case series of 4 children and 17 adults with SSD, treated with cochlear implantation. The outcome of adult patients was compared with a control group of 27 patients with bilateral profound hearing loss using a cochlear implant. Results: During 12 months, the mean speech recognition score increased from 30 to 41% for monosyllabic words in adults, and from 58 to 89% for multisyllabic numbers. The cochlear implant (CI) improved hearing in noise in all SSD patients, as was demonstrated by a significant improvement of the speech reception threshold in different speech and noise configurations. Sound localization-correlated angle detection error improved with CI use at every time point. The maximum word recognition score for monosyllabic words in quiet correlated with the logarithm of the duration of deafness; improvement of the speech reception threshold and RMS angle detection error by the CI did not. Conclusion: All SSD patients benefitted from the CI in different hearing situations. Patients with SSD for a long period can improve after cochlear implantation.
|Management of Cochlear Implant Electrode Migration|
Objective: The present study reviewed a cochlear implant (CI) patient population after surgery, which received a free-fitting electrode carrier designed for hearing preservation. The aim was to determine the rate of electrode migration of the CI electrodes and present clinical and surgical implications. Study Design: Retrospective patient review. Setting: Tertiary referral university hospital. Patients: Two hundred seventy-eight patients implanted uni- or bilaterally with lateral wall electrodes designed for hearing preservation (358 implants). The control group was 323 patients implanted uni- or bilaterally with preformed perimodiolar electrodes (468 implants). Interventions: Determination of CI electrode migration was conducted according to a clinical test protocol. Revision surgery was offered in confirmed patients of electrode migration. A bone groove was considered to improve the fixation of the electrode. Main Outcome Measures: Audiological testing including speech audiometry, subjective sound quality rating, and bilateral pitch comparison in bilateral patients, as well as radiological examinations, were conducted. Results: Electrode migration was observed solely in patients implanted with lateral wall electrodes; 10 of 358 patients with free-fitting electrodes (2.8%) had electrode migration, which was successfully confirmed by the proposed clinical test protocol. Nine of the 10 confirmed patients underwent reinsertion surgery. Mean perception score decreased from 75.0% to 62.1% after electrode migration and recovered completely after reinsertion surgery. A flowchart to detect electrode migration was designed for clinical practice. Conclusion: Although electrode migration is a rare complication in CI surgery, long-term follow-up diagnostics should include a test protocol to detect electrode shifts of lateral wall electrode arrays. A reinsertion surgery should be conducted in confirmed patients to recover speech perception.
|Hearing Preservation With a Midscalar Electrode Comparison of a Regular and Steroid/Pressure Optimized Surgical Approach in Patients With Residual Hearing|
Objective: The aim of this study was to observe the rate of hearing preservation with a midscalar electrode with two surgical approaches. Study Design: Prospective study. Setting: Tertiary referral center. Patients: Twenty patients with residual hearing. Group A: 11 patients (mean age 56.1, 4 men, 7 women) mean HL 250 Hz, 36.4 dB; 500 Hz, 50.0 dB and 1 kHz, 81.4 dB. Group B: nine patients (mean age, 52.8 yr, 7 women, 2 men), 250 Hz, 36.7 dB; 500 Hz, 49.4 dB and 1 kHz, 87.8 dB. Intervention: Implantation with a midscalar electrode with two surgical approaches. Group A approach consisted of a slow insertion (2 min), careful round window opening, tool insertion, intraoperative and postoperative iv. prednisone, tool insertion and 24 hour postoperation bed-rest. In group B additionally the round window was widely opened and the electrode was wetted with triamcinolone. Main Outcome Measure: Measurement of the mean hearing loss in both groups. Results: We observed a statistically significant different hearing preservation for groups A and B. Although group A reached a mean hearing loss (250, 500, 1 kHz) of 42.6 dB, group B showed a mean loss of residual hearing of 9.1 dB after 1 month. Conclusion: A substantial rate of hearing preservation can be achieved with a midscalar electrode. A hearing preserving approach focusing on decreasing the intracochlear fluid pressure and local steroids has a strong effect on the hearing preservation.
|Long-term Hearing Preservation Outcomes After Cochlear Implantation for Electric-Acoustic Stimulation|
Objective: This study reviewed outcomes of hearing preservation (HP) surgery in a cochlear implant patient population, with clinical follow-up results up to 11 years after implantation. Study Design: Retrospective case review. Setting: Tertiary referral university hospital. Patients: Ninety six patients (103 ears) with partial deafness who underwent HP surgery at the University Hospital Frankfurt since 1999 were included. Electrode carriers were Cochlear Slim Straight, MED-EL Standard, Medium, Flex20, and Flex24. Intervention: Cochlear implantation using the HP surgery technique with either the cochleostomy or round window approach. Main Outcome Measures: Pure-tone averages for low frequencies (125 Hz, 250 Hz, 500 Hz, PTAlow) and speech perception scores of the Freiburg monosyllable and number tests in quiet. PTAlow shifts were used to evaluate HP as complete for ≤10 dB, partial between 10 and 30 dB, and minimal for ≥30 dB. Time intervals were: preoperative, postoperative, after 12 months, and long-term (>24 months, mean 51.4 months, range 2–11 years). Impacts of electrode design and surgical approach were analyzed. Results: Postoperatively (n = 103), HP was complete in 32 (31.1%), partial in 49 (47.6%), minimal in 14 (13.6%), and loss of hearing occurred in 8 cases (7.8%). After 12 months (n = 81), HP was complete in 22 (27.2%), partial in 33 (40.7%), minimal in 11 (13.6%), and loss of hearing occurred in 7 additional cases. For long-term outcomes (n = 62) HP was complete in 7 (11.3%), partial in 24 (38.7%), minimal in 9 (14.5%), and loss of hearing occurred in 7 additional cases (total 22/103, 21.4%). Cases with residual hearing who could utilize acoustic amplification (i.e., PTAlow < 80 dB HL) were 82/95 (85.3%) postoperatively, 58/66 (87.9%) after 12 months, and 38/40 (95.0%) for long-term outcomes. Conclusions: Long-term HP is feasible in a subset of patients. Patients with sufficient long-term residual hearing had the prerequisite to benefit from additional acoustic stimulation. No correlation of total hearing loss with etiology, electrode design, or surgical approach was evident. Apart from individual effects of structural damage or inflammation, genetic factors are suggested to influence HP. Cases with total hearing loss still demonstrated successful speech perception in long-term monosyllable recognition scores.
|Adult Cochlear Implant Users Are Able to Discriminate Basic Tonal Features in Musical Patterns: Evidence From Event-related Potentials|
Objective: Measurement of electrophysiological correlates of discrimination abilities of basic musical features in pre- and postlingually deafened adult cochlear implant (CI) users. Study Design: Electroencephalographic study. Comparison between CI users and matched normal hearing controls. Patients: Thirty-six hearing impaired adults using a cochlear implant for 4 to 15 months. Profound hearing impairment was acquired either before (N = 12) or after language acquisition (N = 17). Seven patients suffered from a single-sided deafness. Methods: Presentation of auditory stimuli consisting of musical four tone standard patterns and deviant patterns varying with regard to tone pitch, timbre, intensity, and rhythm of two different degrees. Analysis of electrophysiological, event-related mismatch responses. Results: Cochlear implant users elicited significant mismatch responses on most deviant features. Comparison to controls revealed significantly smaller mismatch negativity amplitudes. Except for one parameter (pitch) there were no reliable differences between pre- and postlingually deafened CI users. Conclusion: Despite a highly reduced complexity of neural auditory stimulation by the cochlear implant device in comparison to the physiological cochlear input, CI users exhibit cortical discriminatory responses to relatively subtle basic tonal alterations.
|Impact of Prosthesis Length on Tympanic Membrane's and Annular Ligament's Stiffness and the Resulting Middle Ear Sound Transmission|
Hypothesis: Prosthesis' length creates tension in ossicular reconstructions, which directly effects the middle ear sound transmission. Background: Relatively long prostheses are often used to stabilize the middle ear reconstruction to prevent dislocation. Thereby, tension on the flexible components such as the tympanic membrane (TM) and the annular ligament (AL) is increased. Only little is known on the amount of displacement-related stiffening of the TM and AL, as well as the consecutive reduction in middle ear transfer function (METF). Methods: An expandable total ossicular replacement prosthesis was tensionfree inserted in nine cadaveric temporal bones between the malleus handle and the stapes footplate. Upon heat activation the prosthesis was lengthened, thus inducing tension on the reconstruction. The METF was assessed before and after elongation. TM's and AL's stiffness were determined by measuring their force–displacement characteristics. Results: Upon activation the prostheses were elongated between 50 and 200 μm. A frequency-dependent METF reduction was measured with a decrease of 5 to 25 dB below 1.0 kHz. At frequencies >2.0 kHz the reduction was less prominent or the METF showed even an improvement of up to 10 dB. TM's stiffness remained constant during the elongation-induced displacement, whereas the AL's stiffness increased. The METF reduction below 1.0 kHz correlated with the increasing AL's stiffness. Conclusion: Tension has a significant impact on the METF after middle ear reconstruction. As little tension as possible should be used to enable best sound transmission. Stabilization of prosthesis should be achieved with dislocation devices to ensure secure coupling to the ossicular remnants without creating additional tension.
|Adaptive Mechanical Stabilization of a Free-Floating Fully Implantable Hearing Aid|
Hypothesis: An implantable acousto-mechanical transducer will yield a higher output if its mass can be virtually increased through the use of a secondary actuator. Background: Current hearing aids and implants rely on feedback compensation to prevent instability (e.g. howling), usually in the form of a digital or analogue filter. We examine the effect of mechanically stabilizing a piezo-driven mechanical amplifier inserted into the incudostapedial joint gap. The aim of this study is to determine whether this is possible and discern the advantages and disadvantages of the design. Methods: We examine a 10:1 scale model of a prospective implantable hearing aid comprising one piezoelectric sensor and two independent piezoelectric actuators in a single-titanium housing. As expected, the maximum gain of the device is limited by feedback between sensor input and the output of the primary actuator. The secondary actuator is used to provide a counter force to the recoil of the primary output piezo. This adds a virtual mass to the device, effectively reducing feedback in the mechano-acoustic path. The compensation unit (CU) described here is driven by a real-time adaptive control algorithm. Results: Using the above approach, we observe an added stable gain of >30 dB, and report a functional hearing gain of up to 40 dB. Physical and digital feedback compensation can be employed in parallel for best results. The experimental data is backed by computer simulations. Conclusion: These results compare favorably with previous studies of a two-piezo transducer with digital feedback control and show the potential for the transducer as a hearing aid for high-frequency hearing loss.
|Intracranial Pressure and Promontory Vibration With Soft Tissue Stimulation in Cadaveric Human Whole Heads|
Hypothesis: Intracranial pressure and skull vibrations are correlated and depend on the stimulation position and frequency. Background: A hearing sensation can be elicited by vibratory stimulation on the skin covered skull, or by stimulation on soft tissue such as the neck. It is not fully understood whether different stimulation sites induce the skull vibrations responsible for the perception or whether other transmission pathways are dominant. The aim of this study was to assess the correlation between intracranial pressure and skull vibration measured on the promontory for stimulation to different sites on the head. Methods: Measurements were performed on four human cadaver heads. A bone conduction hearing aid was held in place with a 5-Newton steel headband at four locations (mastoid, forehead, eye, and neck). While stimulating in the frequency range of 0.3 to 10 kHz, acceleration of the cochlear promontory was measured with a Laser Doppler Vibrometer, and intracranial pressure at the center of the head with a hydrophone. Results: Promontory acceleration and intracranial pressure was measurable for all stimulation sites. The ratios were comparable between all stimulation sites for frequencies below 2 kHz. Conclusion: These findings indicate that both promontory acceleration and intracranial pressure are involved for stimulation on the sites investigated. The transmission pathway of sound energy is comparable for the four stimulation sites.
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