Frankfurt concept of early inpatient rehabilitation after cochlear implant treatment : Feasibility for aftercare.

BACKGROUND: The Association of the Scientific Medical Societies in Germany (AWMF) clinical practice guideline on cochlear implant (CI) treatment, which was updated in 2020, defined the entire process of CI care for the first time. In the present study, the feasibility and results of very early rehabilitation were examined. MATERIALS AND METHODS: The intervention group (IG) comprised 54 patients in whom rehabilitation was initiated within 14 (maximally 28) days after implantation. Patients with a significantly longer waiting time were included in the control group (CG, n = 21). In addition to the start and duration of rehabilitation, the speech intelligibility achieved with CI was recorded at different timepoints within a 12-month period. In addition, questionnaires were used to assess the effort of fitting the CI processor and the patients' satisfaction with the outcome as well as the timing of the start of rehabilitation. RESULTS: Median waiting time between implantation and start of rehabilitation was 14 days in the IG and 106 days in the CG; 92.6% of IG patients were able to start rehabilitation within 14 days. The effect of rehabilitation in the IG was 35 and in the CG 25 percentage points (Freiburg monosyllabic test). After 6 and 12 months of CI use, both groups showed comparable results in the test condition in quiet (IG/CG 6 months: 70%/70%; 12 months: 70%/60%, Freiburg monosyllabic test) and in noise (IG/CG 6 months: -1.1 dB SNR/-0.85 dB SNR; 12 months: -0.65 dB SNR/+0.3 dB SNR, Oldenburg sentence test). Hearing quality assessment scores collected by SSQ (Speech, Spatial and Qualities of Hearing Scale) questionnaire showed better scores in the IG at 6 months, which converged to CG scores at 12 months. The IG was significantly more satisfied with the timing of the start of rehab than the CG. All other data obtained from questionnaires showed no differences between the two groups. CONCLUSION: A very early start of inpatient rehabilitation after cochlear implantation was successfully implemented. The rehabilitation was completed within 7 weeks of CI surgery. Comparison of speech recognition test results before and after rehabilitation showed a significant improvement. A clear rehabilitation effect can therefore be demonstrated. Inclusion of CI rehabilitation in the German catalog of follow-up treatments is thus scientifically justified and therefore strongly recommended.

Outcome Prediction of Speech Perception in Quiet and in Noise for Cochlear Implant Candidates Based on Pre-Operative Measures.

(1) Background: The fitting of cochlear implants (CI) is an established treatment, even in cases with considerable residual hearing but insufficient speech perception. The aim of this study was to evaluate a prediction model for speech in quiet and to provide reference data and a predictive model for postoperative speech perception in noise (SPiN) after CI provision. (2) Methods: CI candidates with substantial residual hearing (either in hearing threshold or in word recognition scores) were included in a retrospective analysis (n = 87). Speech perception scores in quiet 12 months post-surgery were compared with the predicted scores. A generalized linear model was fitted to speech reception thresholds (SRTs) after CI fitting to identify predictive variables for SPiN. (3) Results: About two-thirds of the recipients achieved the expected outcome in quiet or were better than expected. The mean absolute error of the prediction was 13.5 percentage points. Age at implantation was the only predictive factor for SPiN showing a significant correlation (r = 0.354; p = 0.007). (4) Conclusions: Outcome prediction accuracy for speech in quiet was comparable to previous studies. For CI recipients in the included study population, the SPiN outcome could be predicted only based on the factor age.

[Frankfurt concept of early inpatient rehabilitation after cochlear implant treatment : Feasibility for aftercare. German version]. / Frankfurter Konzept einer stationären Cochleaimplantat-Frührehabilitation : Untersuchung zur Durchführbarkeit als Anschlussheilbehandlung.

BACKGROUND: The Association of the Scientific Medical Societies in Germany (AWMF) clinical practice guideline on cochlear implant (CI) treatment, which was updated in 2020, defined the entire process of CI care for the first time. In the present study, the feasibility and results of very early rehabilitation were examined. MATERIALS AND METHODS: The intervention group (IG) comprised 54 patients in whom rehabilitation was initiated within 14 (maximally 28) days after implantation. Patients with a significantly longer waiting time were included in the control group (CG, n = 21). In addition to the start and duration of rehabilitation, the speech intelligibility achieved with CI was recorded at different timepoints within a 12-month period. In addition, questionnaires were used to assess the effort of fitting the CI processor and the patients' satisfaction with the outcome as well as the timing of the start of rehabilitation. RESULTS: Median waiting time between implantation and start of rehabilitation was 14 days in the IG and 106 days in the CG; 92.6% of IG patients were able to start rehabilitation within 14 days. The effect of rehabilitation in the IG was 35 and in the CG 25 percentage points (Freiburg monosyllabic test). After 6 and 12 months of CI use, both groups showed comparable results in the test condition in quiet (IG/CG 6 months: 70%/70%; 12 months: 70%/60%, Freiburg monosyllabic test) and in noise (IG/CG 6 months: -1.1-0.85 dB SNR; 12 months: -0.65 dB SNR/0.3 dB SNR, Oldenburg sentence test). Hearing quality assessment scores collected by SSQ (Speech, Spatial and Qualities of Hearing Scale) questionnaire showed better scores in the IG at 6 months, which converged to CG scores at 12 months. The IG was significantly more satisfied with the timing of the start of rehab than the CG. All other data obtained from questionnaires showed no differences between the two groups. CONCLUSION: A very early start of inpatient rehabilitation after cochlear implantation was successfully implemented. The rehabilitation was completed within 7 weeks of CI surgery. Comparison of speech recognition test results before and after rehabilitation showed a significant improvement. A clear rehabilitation effect can therefore be demonstrated. Inclusion of CI rehabilitation in the German catalog of follow-up treatments is thus scientifically justified and therefore strongly recommended.

Cochlear implant therapy improves the quality of life and social participation in the elderly: a prospective long-term evaluation.

PURPOSE: In recent years, the number of elderly cochlear implant (CI) candidates is continuously rising. In addition to the audiological improvement, other positive effects of CI treatment can also be observed in clinical routine. The "quality of life" as a parameter of success directly experienced by the patient is increasingly becoming the focus of clinical research. Although there are already clear indications of a rapid and significant improvement in quality of life, there is still a lack of systematic, prospectively collected longitudinal long-term data in patients over the age of 65. METHODS: This prospective longitudinal observational study included 31 patients between the age of 71 and 92 years who had first been treated unilaterally with a CI 6 years ago. In addition to free-field monosyllable recognition, quality of life was assessed using the World Health Organization Quality-of-Life Scale-old (WHOQL-OLD). The results were compared with the data from our previous study, in which we focused on the short- and medium-term effects on quality of life. In both studies, the same patient population was examined. In addition, these study data were compared with an age-matched average population. RESULTS: In speech recognition, there was no significant change from the control 6 months postoperatively compared with the results 6 years postoperatively. No significant changes occurred in the total quality of life score or any of the other six facets of quality of life when comparing the results 6 months postoperatively with the results 6 years postoperatively. In "Social participation", the CI patients even exceed the values of the age-matched average population 6 years after treatment. CONCLUSION: Improvement in the quality of life and especially in social participation appears stable over many years in elderly patients after hearing rehabilitation with a CI.

Comparison of hearing performance in patients with borderline indication for active middle ear or cochlear implants: clinical outcomes to guide preoperative counseling and decision making.

PURPOSE: The aim of the presented study was to compare the audiological benefit achieved in cochlear implant (CI) patients who, in principle, could still have been treated with an active middle ear implant (AMEI) with a group of AMEI users. METHODS: Results of 20 CI patients with a pure-tone average (PTA) of 70 dB HL prior to surgery were compared with a group of 12 subjects treated with a Vibrant Soundbridge (VSB). Pre-surgical comparison included PTA for air conduction and bone conduction, maximum speech recognition score for monosyllabic words (WRSmax), and aided monosyllabic word recognition at 65 dB SPL. One year after surgery, aided monosyllabic speech recognition score at 65 dB SPL was compared. RESULTS: Mean PTA for air conduction in the VSB group was significantly lower than in the CI group (4.8 dB, Z = - 2.011, p < 0.05). Mean PTA for bone conduction in the VSB group was also significantly lower than in the CI group (23.4 dB, Z = - 4.673, p < 0.001). WRSmax in the VSB group was significantly better than in the CI group (40.7%, Z = - 3.705, p < 0.001). One year after treatment, there was no significant difference in aided speech perception in quiet between both subject groups. CONCLUSION: Comparison of the two methods showed equivalent results for both treatments in subjects with a borderline indication. Not only pure-tone audiometry results but, particularly, speech perception scores pre-surgery should be taken into account in preoperative counseling.

Speech perception in modulated noise assessed in bimodal CI users.

BACKGROUND: Although good speech perception in quiet is achievable with cochlear implants (CIs), speech perception in noise is severely impaired compared to normal hearing (NH). In the case of a bimodal CI fitting with a hearing aid (HA) in the opposite ear, the amount of residual acoustic hearing influences speech perception in noise. OBJECTIVE: The aim of this work was to investigate speech perception in noise in a group of bimodal CI users and compare the results to age-matched HA users and people without subjective hearing loss, as well as with a young NH group. MATERIALS AND METHODS: Study participants comprised 19 bimodal CI users, 39 HA users, and 40 subjectively NH subjects in the age group 60-90 years and 14 young NH subjects. Speech reception thresholds (SRTs) in noise were adaptively measured using the Oldenburg Sentence Test for the two spatial test conditions S0N0 (speech and noise from the front) and multisource-noise field (MSNF; speech from the front, four spatially distributed noise sources) in continuous noise of the Oldenburg Sentence Test (Ol-noise) and amplitude-modulated Fastl noise (Fastl-noise). RESULTS: With increasing hearing loss, the median SRT worsened significantly in all conditions. In test condition S0N0, the SRT of the CI group was 5.6 dB worse in Ol-noise than in the young NH group (mean age 26.4 years) and 22.5 dB worse in Fastl-noise; in MSNF, the differences were 6.6 dB (Ol-noise) and 17.3 dB (Fastl-noise), respectively. In the young NH group, median SRT in condition S0N0 improved by 11 dB due to gap listening; in the older NH group, SRTs improved by only 3.1 dB. In the HA and bimodal CI groups there was no gap listening effect and SRTs in Fastl-noise were even worse than in Ol-noise. CONCLUSION: With increasing hearing loss, speech perception in modulated noise is even more impaired than in continuous noise.

[Speech perception in modulated noise assessed in bimodal CI users-German version]. / Sprachverstehen im modulierten Störgeräusch bei bimodal versorgten CI-Tragenden.

BACKGROUND: Although good speech perception in quiet is achievable with cochlear implants (CIs), speech perception in noise is severely impaired compared to normal hearing (NH). In the case of a bimodal CI fitting with a hearing aid (HA) in the opposite ear, the amount of residual acoustic hearing influences speech perception in noise. OBJECTIVE: The aim of this work was to investigate speech perception in noise in a group of bimodal CI users and compare the results to age-matched HA users and people without subjective hearing loss, as well as with a young NH group. MATERIALS AND METHODS: Study participants comprised 19 bimodal CI users, 39 HA users, and 40 subjectively NH subjects in the age group 60-90 years and 14 young NH subjects. Speech reception thresholds (SRTs) in noise were adaptively measured using the Oldenburg Sentence Test for the two spatial test conditions S0N0 (speech and noise from the front) and multisource-noise field (MSNF; speech from the front, four spatially distributed noise sources) in continuous noise of the Oldenburg Sentence Test (Ol-noise) and amplitude-modulated Fastl noise (Fastl-noise). RESULTS: With increasing hearing loss, the median SRT worsened significantly in all conditions. In test condition S0N0, the SRT of the CI group was 5.6 dB worse in Ol-noise than in the young NH group (mean age 26.4 years) and 22.5 dB worse in Fastl-noise; in MSNF, the differences were 6.6 dB (Ol-noise) and 17.3 dB (Fastl-noise), respectively. In the young NH group, median SRT in condition S0N0 improved by 11 dB due to gap listening; in the older NH group, SRTs improved by only 3.1 dB. In the HA and bimodal CI groups there was no gap listening effect and SRTs in Fastl-noise were even worse than in Ol-noise. CONCLUSION: With increasing hearing loss, speech perception in modulated noise is even more impaired than in continuous noise.

Factors influencing the relationship between cochlear health measures and speech recognition in cochlear implant users.

Background: One factor which influences the speech intelligibility of cochlear implant (CI) users is the number and the extent of the functionality of spiral ganglion neurons (SGNs), referred to as "cochlear health." To explain the interindividual variability in speech perception of CI users, a clinically applicable estimate of cochlear health could be insightful. The change in the slope of the electrically evoked compound action potentials (eCAP), amplitude growth function (AGF) as a response to increased interphase gap (IPG) (IPGEslope) has been introduced as a potential measure of cochlear health. Although this measure has been widely used in research, its relationship to other parameters requires further investigation. Methods: This study investigated the relationship between IPGEslope, demographics and speech intelligibility by (1) considering the relative importance of each frequency band to speech perception, and (2) investigating the effect of the stimulus polarity of the stimulating pulse. The eCAPs were measured in three different conditions: (1) Forward masking with anodic-leading (FMA) pulse, (2) Forward masking with cathodic-leading (FMC) pulse, and (3) with alternating polarity (AP). This allowed the investigation of the effect of polarity on the diagnosis of cochlear health. For an accurate investigation of the correlation between IPGEslope and speech intelligibility, a weighting function was applied to the measured IPGEslopes on each electrode in the array to consider the relative importance of each frequency band for speech perception. A weighted Pearson correlation analysis was also applied to compensate for the effect of missing data by giving higher weights to the ears with more successful IPGEslope measurements. Results: A significant correlation was observed between IPGEslope and speech perception in both quiet and noise for between-subject data especially when the relative importance of frequency bands was considered. A strong and significant correlation was also observed between IPGEslope and age when stimulation was performed with cathodic-leading pulses but not for the anodic-leading pulse condition. Conclusion: Based on the outcome of this study it can be concluded that IPGEslope has potential as a relevant clinical measure indicative of cochlear health and its relationship to speech intelligibility. The polarity of the stimulating pulse could influence the diagnostic potential of IPGEslope.

Impact of processing-latency induced interaural delay and level discrepancy on sensitivity to interaural level differences in cochlear implant users.

PURPOSE: This study investigated whether an interaural delay, e.g. caused by the processing latency of a hearing device, can affect sensitivity to interaural level differences (ILDs) in normal hearing subjects or cochlear implant (CI) users with contralateral normal hearing (SSD-CI). METHODS: Sensitivity to ILD was measured in 10 SSD-CI subjects and in 24 normal hearing subjects. The stimulus was a noise burst presented via headphones and via a direct cable connection (CI). ILD sensitivity was measured for different interaural delays in the range induced by hearing devices. ILD sensitivity was correlated with results obtained in a sound localization task using seven loudspeakers in the frontal horizontal plane. RESULTS: In the normal hearing subjects the sensitivity to interaural level differences deteriorated significantly with increasing interaural delays. In the CI group, no significant effect of interaural delays on ILD sensitivity was found. The NH subjects were significantly more sensitive to ILDs. The mean localization error in the CI group was 10.8° higher than in the normal hearing group. No correlation between sound localization ability and ILD sensitivity was found. CONCLUSION: Interaural delays influence the perception of ILDs. For normal hearing subjects a significant decrement in sensitivity to ILD was measured. The effect could not be confirmed in the tested SSD-CI group, probably due to a small subject group with large variations. The temporal matching of the two sides may be beneficial for ILD processing and thus sound localization for CI patients. However, further studies are needed for verification.

Exponential fitting of spread of excitation response measurements in cochlear implants.

BACKGROUND: Hearing performance in cochlear implant (CI) users is variable. An objective measure which can allow a prediction of this performance is desirable. Spread of neural excitation (SoE) curves are an objective measure that can be obtained using the fitting software of cochlear implants and might be able to be used as a predictor. A novel method to interpret SoE curves is presented. NEW METHOD: Spread of excitation measurements for three recording sites were fitted using two exponential functions. An asymmetric width measure was developed, defined as the distance in mm to the point, where 25% or 50% of peak normalized amplitude was reached, for each half of the SoE separately. Also, a novel population of subjects with MED-EL CIs is used. Furthermore, speech perception (speech reception threshold, SRT) was evaluated using a matrix sentence test in a multi-source noise field. RESULTS: SoE width was narrowest for the basal recording site and widest for the apical recording site. Fitted SoE exponential functions were most asymmetric for the apical recording site. A significant positive correlation between sentence test SRT and SoE width at the apical recording site was found. COMPARISON WITH EXISTING METHODS: The use of an asymmetric width measure correlated strongly and positively with speech perception for apical recording sites, unlike the symmetric width measure used in previous studies. Presumably, longer electrodes allow stimulation of a more apical part of the cochlear. At the apical part of the cochlea, dendrites from a large region of the basilar membrane map to a narrow portion on the spiral ganglion, which might explain the observed asymmetry. CONCLUSIONS: For subjects implanted with long electrode arrays, an asymmetric width measure correlates positively with apical SoE distance. However, due to lack of a sufficient amount of data, the results are currently less conclusive and need to be consolidated in a larger cohort of subjects.

Residual low-frequency hearing after early device activation in cochlear implantation.

PURPOSE: The cochlear implant (CI) is a standard treatment for patients with severe to profound hearing loss. In recent years, early device activation of the sound processor after 2-3 days following surgery has been established. The aim of this study is to evaluate the residual hearing of CI patients with substantial preoperative low-frequency hearing after early device activation over a period of 12 months. METHODS: Results were compared between an early fitted group (EF) with device activation to less than 15 days after CI surgery and a control group (CG) with device activation after 3-6 weeks. In total, 57 patients were divided into EF group (n = 32), and CG (n = 25). Low-frequency residual hearing and speech recognition in quiet and in noise were compared over an observation period of 12 months. RESULTS: No significant difference (p > 0.05) in the residual low-frequency hearing PTAlow between EF and CG was found, neither preoperatively (EF 33.2 dB HL/CG 35.0 dB HL), nor postoperatively (EF 46.8 dB HL/CG 46.2 dB HL). In both groups, postoperative residual hearing decreased compared to preoperative and remained stable within the first year after CI surgery. Furthermore, both groups showed no significant differences (p > 0.05) in speech recognition in quiet and in noise within the first year. CONCLUSION: Early device activation is feasible in CI patients with preoperative low-frequency residual hearing, without an additional effect on postoperative hearing preservation.

[Has the SARS-CoV-2 pandemic improved teaching?-Virtual education in otorhinolaryngology from the students' perspective]. / Hat die SARS-CoV-2-Pandemie die Lehre verbessert? ­ Virtueller Unterricht im Fach HNO-Heilkunde aus Sicht der Studierenden.

BACKGROUND: The Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV­2) pandemic has significantly changed the education of medical students. Due to the contact restrictions and the associated requirement for distance learning, digital teaching formats had to be implemented within a short period of time. The aim of our work was to analyze student evaluation data for virtual teaching in otorhinolaryngology (ORL) during the SARS-CoV­2 pandemic and to compare the data with previously obtained evaluation data under face-to-face conditions. MATERIALS AND METHODS: Evaluation data for the block practical courses in winter semester 2020/21 and summer semester 2021, which were carried out in a virtual format with a short face-to-face phase as well as those for the block practical courses from summer semester 2018 to winter semester 2019/20, which had been performed completely in a conventional face-to-face format, were analyzed. The anonymous survey of the students focused on various aspects of the courses such as organization, didactics and learning atmosphere. RESULTS: Of 16 surveyed categories, 14 (87.5%) showed significantly better evaluation results for the virtual courses compared to the courses carried out previously under face-to-face conditions. This very positive assessment of the digital teaching offer showed no significant change during the course of the pandemic over the period of two semesters. CONCLUSIONS: Our data show a high acceptance of digital teaching in ORL for students. Even though essential components of the medical education such as teaching on the patient and clinical-practical skills can still only be realized in a face-to-face format, our data suggest that digital elements could also play a role in medical education after the SARS-CoV­2 pandemic.

The Importance of a Preinsertion Integrity Device Test of Cochlear Implants.

OBJECTIVES: The surgery of a cochlear implant is a complex interdisciplinary procedure with high quality standards to ensure patients safety and implant durability. An integrity test of the device prior to insertion is an additional tool to improve quality standards by detecting potentially malfunctioning implants without burdening the patient. METHODS: At the Department of Otorhinolaryngology, University Hospital Frankfurt a. M. (Germany) since 2010 an integrity device test ("pre-insertion telemetry") has been performed prior to the implantation of a cochlear implant. The preinsertion telemetry measures the electrical impedances of the implant electrode contacts in conductive saline solution and thereby confirms regular bidirectional data transmission and electrode integrity. In the case of irregular results with suspected implant malfunction, the device was discarded during surgery and returned to the manufacturer for further technical review. Data and test results of the preinsertion telemetry and from rejected implants (manufacturers' reports) between January 2010 and December 2020 were analyzed. RESULTS: From 2010 to 2020, 1,926 cochlear implants from three manufacturers were implanted at our institution. All implants had fully functioning bidirectional data transmission. 15 implants had irregular preinsertion telemetry results (electrode circuit failures) and were rejected during surgery. In 13 cases, the manufacturer confirmed implant malfunction. In the last 5 years, only one implant with irregular preinsertion telemetry was detected. CONCLUSION: Preinsertion telemetry is strongly recommended as a quick and reliable integrity test of the device to confirm the functionality of a cochlear implant.

Age Differences in Speech Perception in Noise and Sound Localization in Individuals With Subjective Normal Hearing.

Hearing loss in old age, which often goes untreated, has far-reaching consequences. Furthermore, reduction of cognitive abilities and dementia can also occur, which also affects quality of life. The aim of this study was to investigate the hearing performance of seniors without hearing complaints with respect to speech perception in noise and the ability to localize sounds. Results were tested for correlations with age and cognitive performance. The study included 40 subjects aged between 60 and 90 years (mean age: 69.3 years) with not self-reported hearing problems. The subjects were screened for dementia. Audiological tests included pure-tone audiometry and speech perception in two types of background noise (continuous and amplitude-modulated noise) which was either co-located or spatially separated (multi-source noise field, MSNF) from the target speech. Sound localization ability was assessed and hearing performance was self-evaluated by a questionnaire. Speech in noise and sound localization was compared with young normal hearing adults. Although considering themselves as hearing normal, 17 subjects had at least a mild hearing loss. There was a significant negative correlation between hearing loss and dementia screening (DemTect) score. Speech perception in noise decreased significantly with age. There were significant negative correlations between speech perception in noise and DemTect score for both spatial configurations. Mean SRTs obtained in the co-located noise condition with amplitude-modulated noise were on average 3.1 dB better than with continuous noise. This gap-listening effect was severely diminished compared to a younger normal hearing subject group. In continuous noise, spatial separation of speech and noise led to better SRTs compared to the co-located masker condition. SRTs in MSNF deteriorated in modulated noise compared to continuous noise by 2.6 dB. Highest impact of age was found for speech perception scores using noise stimuli with temporal modulation in binaural test conditions. Mean localization error was in the range of young adults. Mean amount of front/back confusions was 11.5% higher than for young adults. Speech perception tests in the presence of temporally modulated noise can serve as a screening method for early detection of hearing disorders in older adults. This allows for early prescription of hearing aids.

Long-term effects on the quality of life following cochlear implant treatment in older patients.

PURPOSE: Even in older patients, hearing rehabilitation with a cochlear implant has become an established method for deafened or severely hearing-impaired patients. In addition to the hearing improvement, numerous other effects of CI treatment can be observed in clinical routine. In the literature, there is multiple evidence for a rapid and significant improvement in quality of life with CI treatment. The aim of this study was to evaluate the long-term effects of hearing rehabilitation using CI on the quality of life in older patients (≥ 65 years). METHODS: This prospective cross-sectional study examined 84 patients between the age of 65 and 101 years who received unilateral CI treatment for the first time between one and 10 years ago. The World Health Organization Quality-of-Life Scale-Old (WHOQL-OLD) was used to determine the quality of life. The study cohort was divided into three groups to compare the quality of life over time: group I (1-3 years after CI treatment), group II (4-6 years after CI treatment), and group III (7-10 years after CI treatment). In addition, the data from this study were compared with the results of our previous study (Issing et al. 2020) in which we focused on the first 6 months after CI treatment. RESULTS: In all three groups, there was a significant improvement in monosyllabic discrimination within 1 year after CI fitting (p > 0.001). No significant differences were found between the three groups. There were no significant differences between the three groups in the WHOQOL-OLD total score (p = 0.487) or any of the other six facets. Moreover, no significant differences were found compared to the study group of our previous study 6 months after CI treatment. CONCLUSION: This study demonstrates the long-term stability of the improved quality of life following unilateral CI treatment in patients aged 65 years or older.

Evaluation of a Transimpedance Matrix Algorithm to Detect Anomalous Cochlear Implant Electrode Position.

INTRODUCTION: Transimpedance measurements from cochlear implant electrodes have the potential to identify anomalous electrode array placement, such as tip fold-over (TFO) or fold-back, basal electrode kinking, or buckling. Analysing transimpedance may thus replace intraoperative or post-operative radiological imaging to detect any potential misplacements. A transimpedance algorithm was previously developed to detect deviations from a normal electrode position with the aim of intraoperatively detecting TFO. The algorithm had been calibrated on 35 forced, tip folded electrode arrays in six temporal bones to determine the threshold criterion required to achieve a sensitivity of 100%. Our primary objective here was to estimate the specificity of this TFO algorithm in patients, in a prospective study, for a series of electrode arrays shown to be normally inserted by post-operative imaging. METHODS: Intracochlear voltages were intraoperatively recorded for 157 ears, using Cochlear's Custom Sound™ EP 5 electrophysiological software (Cochlear Ltd., Sydney, NSW, Australia), for both Nucleus® CI512 and CI532 electrode arrays. The algorithm analysed the recorded 22 × 22 transimpedance matrix (TIM) and results were displayed as a heatmap intraoperatively, only visible to the technician in the operating theatre. After all clinical data were collected, the algorithm was evaluated on the bench. The algorithm measures the transimpedance gradients and corresponding phase angles (θ) throughout the TIM and calculates the gradient phase range. If this was greater than the predetermined threshold, the algorithm classified the electrode array insertion as having a TFO. RESULTS: Five ears had no intraoperative TIM and four anomalous matrices were identified from heatmaps and removed from the specificity analysis. Using the 148 remaining data sets (n = 103 CI532 and n = 45 CI512), the algorithm had an average specificity of 98.6% (95.80%-99.75%). CONCLUSION: The algorithm was found to be an effective screening tool for the identification of TFOs. Its specificity was within acceptable levels and resulted in a positive predictive value of 76%, with an estimated incidence of fold-over of 4% in perimodiolar arrays. This would mean 3 out of 4 cases flagged as a fold-over would be correctly identified by the algorithm, with the other being a false positive. The measurements were applied easily in theatre allowing it to be used as a routine clinical tool for confirming correct electrode placement.

Impact of Reverberation on Speech Perception and Sound Localization Accuracy in Cochlear Implant Users With Single-Sided Deafness.

OBJECTIVES: The aim of this study was to compare the impact of reverberation on sound localization accuracy and speech perception in noise between subjects with single-sided deafness using a cochlear implant (SSD-CI) and a normal-hearing control group. METHODS: Nine SSD-CI subjects and 21 normal-hearing subjects participated in the study. In Experiment 1, the sound localization accuracy was measured with and without reverberation. In Experiment 2, speech reception thresholds were determined with four asymmetrically arranged noise sources in free-field and in reverberation. For the realization of reverberation, a room simulation system comprising of 128 loudspeakers was used. RESULTS: No significant impact of reverberation was found on the sound localization accuracy of the SSD-CI subjects (free-field: 12.6°, reverberation: 11.9°), whereas the normal-hearing subjects performed significantly worse in reverberation (free-field: 1.8°, reverberation: 3.3°).Both subject groups experienced significantly deteriorated speech reception thresholds due to reverberation (pSSD-CI = 0.008, pNH < 0.001). Mean speech reception thresholds in the SSD-CI subjects were -9.7 dB SNR (free-field) and -4.2 dB SNR (reverberation) and a median individual decrease of 5.7 dB SNR in reverberation. Mean speech reception thresholds in the normal-hearing group were -14.0 dB SNR (free-field) and -10.3 dB SNR (reverberation). CONCLUSION: A strong deterioration of sound localization accuracy due to reverberation did not occur. However, although partial restoration of binaural hearing is assumed in SSD-CI users, the impact of reverberation on speech perception in noise is much stronger compared to normal-hearing.

Vertigo Associated With Cochlear Implant Surgery: Correlation With Vertigo Diagnostic Result, Electrode Carrier, and Insertion Angle.

Objective: Vertigo is a common side effect of cochlear implant (CI) treatment. This prospective study examines the incidence of postoperative vertigo over time and aims to analyze influencing factors such as electrode design and insertion angle (IA). Study Design and Setting: This is a prospective study which has been conducted at a tertiary referral center (academic hospital). Patients: A total of 29 adults were enrolled and received a unilateral CI using one of six different electrode carriers, which were categorized into "structure-preserving" (I), "potentially structure-preserving" (II), and "not structure-preserving" (III). Intervention: Subjective vertigo was assessed by questionnaires at five different time-points before up to 6 months after surgery. The participants were divided into four groups depending on the time of the presence of vertigo before and after surgery. Preoperatively and at 6 months postoperatively, a comprehensive vertigo diagnosis consisting of Romberg test, Unterberger test, subjective visual vertical, optokinetic test, video head impulse test, and caloric irrigation test was performed. In addition, the IA was determined, and the patients were divided in two groups (<430°; ≥430°). Main Outcome Measures: The incidence of vertigo after CI surgery (group 1) was reported, as well as the correlation of subjective vertigo with electrode array categories (I-III) and IA. Results: Among the participants, 45.8% experienced new vertigo after implantation. Based on the questionnaire data, a vestibular origin was suspected in 72.7%. The results did not show a significant correlation with subjective vertigo for any of the performed tests. In group 1 with postoperative vertigo, 18% of patients showed conspicuous results in a quantitative analysis of caloric irrigation test despite the fact that the category I or II electrodes were implanted, which are suitable for structure preservation. Average IA was 404° for the overall group and 409° for group 1. There was no statistically significant correlation between IA and perceived vertigo. Conclusions: Though vertigo after CI surgery seems to be a common complication, the test battery used here could not objectify the symptoms. Further studies should clarify whether this is due to the multifactorial cause of vertigo or to the lack of sensitivity of the tests currently in use. The proof of reduced probability for vertigo when using atraumatic electrode carrier was not successful, nor was the proof of a negative influence of the insertion depth.

Interleaved Acoustic Environments: Impact of an Auditory Scene Classification Procedure on Speech Perception in Cochlear Implant Users.

Clinical speech perception tests with simple presentation conditions often overestimate the impact of signal preprocessing on speech perception in complex listening environments. A new procedure was developed to assess speech perception in interleaved acoustic environments of different complexity that allows investigation of the impact of an automatic scene classification (ASC) algorithm on speech perception. The procedure was applied in cohorts of normal hearing (NH) controls and uni- and bilateral cochlear implant (CI) users. Speech reception thresholds (SRTs) were measured by means of a matrix sentence test in five acoustic environments that included different noise conditions (amplitude modulated and continuous), two spatial configurations, and reverberation. The acoustic environments were encapsulated in a randomized, mixed order single experimental run. Acoustic room simulation was played back with a loudspeaker auralization setup with 128 loudspeakers. 18 NH, 16 unilateral, and 16 bilateral CI users participated. SRTs were evaluated for each individual acoustic environment and as mean-SRT. Mean-SRTs improved by 2.4 dB signal-to-noise ratio for unilateral and 1.3 dB signal-to-noise ratio for bilateral CI users with activated ASC. Without ASC, the mean-SRT of bilateral CI users was 3.7 dB better than the SRT of unilateral CI users. The mean-SRT indicated significant differences, with NH group performing best and unilateral CI users performing worse with a difference of up to 13 dB compared to NH. The proposed speech test procedure successfully demonstrated that speech perception and benefit with ASC depend on the acoustic environment.

Impact of Hearing Rehabilitation Using Cochlear Implants on Cognitive Function in Older Patients.

OBJECTIVE: To assess the effects of hearing rehabilitation with cochlear implants on a subset of cognitive domains in older patients (≥65 yr). STUDY DESIGN: Prospective observational study. SETTING: Department of Oto-Rhino-Laryngology, Goethe-University Frankfurt/Main. PATIENTS: Patients aged between 65 and 86 years who have received unilateral cochlear implant (CI) therapy. INTERVENTION: Unilateral cochlear implantation. MAIN OUTCOME MEASURES: The dementia screening test (DemTect) and the trail making test (TMT) were carried out on three occasions: previous to the surgery, at the initial fitting (about 1 month after surgery) and 6 months after surgery. RESULTS: The average overall score on the DemTect scale increased significantly within 6 months of CI treatment (p = 0.049), with verbal aspects improving particularly markedly. The results of the trail making test showed that within 6 months of CI treatment, processing speed increased significantly (TMT A: p = 0.003; TMT B: p = 0.001). CONCLUSION: A pre-post comparison showed that aural rehabilitation with a CI results in an improvement in cognitive subdomains. Further comprehensive randomized-controlled studies may be necessary to evaluate possible confounding variables and to assess long-term results.