International Consensus Statements on Intraoperative Testing for Cochlear Implantation Surgery.

OBJECTIVES: A wide variety of intraoperative tests are available in cochlear implantation. However, no consensus exists on which tests constitute the minimum necessary battery. We assembled an international panel of clinical experts to develop, refine, and vote upon a set of core consensus statements. DESIGN: A literature review was used to identify intraoperative tests currently used in the field and draft a set of provisional statements. For statement evaluation and refinement, we used a modified Delphi consensus panel structure. Multiple interactive rounds of voting, evaluation, and feedback were conducted to achieve convergence. RESULTS: Twenty-nine provisional statements were included in the original draft. In the first voting round, consensus was reached on 15 statements. Of the 14 statements that did not reach consensus, 12 were revised based on feedback provided by the expert practitioners, and 2 were eliminated. In the second voting round, 10 of the 12 revised statements reached a consensus. The two statements which did not achieve consensus were further revised and subjected to a third voting round. However, both statements failed to achieve consensus in the third round. In addition, during the final revision, one more statement was decided to be deleted due to overlap with another modified statement. CONCLUSIONS: A final core set of 24 consensus statements was generated, covering wide areas of intraoperative testing during CI surgery. These statements may provide utility as evidence-based guidelines to improve quality and achieve uniformity of surgical practice.

Minimum intraoperative testing battery for cochlear implantation: the international practice trend.

PURPOSE: In cochlear implantation (CI) surgery, there are a wide variety of intraoperative tests available. However, no clear guide exists on which tests must be performed as the minimum intraoperative testing battery. Toward this end, we studied the usage patterns, recommendations, and attitudes of practitioners toward intraoperative testing. METHODS: This study is a multicentric international survey of tertiary referral CI centers. A survey was developed and administered to a group of CI practitioners (n = 34) including otologists, audiologists and biomedical engineers. Thirty six participants were invited to participate in this study based on a their scientific outputs to the literature on the intraoperative testing in CI field and based on their high load of CI surgeries. Thirty four, from 15 countries have accepted the invitation to participate. The participants were asked to indicate the usage trends, perceived value, influence on decision making and duration of each intraoperative test. They were also asked to indicate which tests they believe should be included in a minimum test battery for routine cases. RESULTS: Thirty-two (94%) experts provided responses. The most frequently recommended tests for a minimum battery were facial nerve monitoring, electrode impedance measurements, and measurements of electrically evoked compound action potentials (ECAPs). The perceived value and influence on surgical decision-making also varied, with high-resolution CT being rated the highest on both measures. CONCLUSION: Facial nerve monitoring, electrode impedance measurements, and ECAP measurements are currently the core tests of the intraoperative test battery for CI surgery.

A phenomenological computational model of the evoked action potential fitted to human cochlear implant responses.

There is a growing interest in biomedical engineering in developing procedures that provide accurate simulations of the neural response to electrical stimulus produced by implants. Moreover, recent research focuses on models that take into account individual patient characteristics. We present a phenomenological computational model that is customized with the patient's data provided by the electrically evoked compound action potential (ECAP) for simulating the neural response to electrical stimulus produced by the electrodes of cochlear implants (CIs). The model links the input currents of the electrodes to the simulated ECAP. Potentials and currents are calculated by solving the quasi-static approximation of the Maxwell equations with the finite element method (FEM). In ECAPs recording, an active electrode generates a current that elicits action potentials in the surrounding auditory nerve fibers (ANFs). The sum of these action potentials is registered by other nearby electrode. Our computational model emulates this phenomenon introducing a set of line current sources replacing the ANFs by a set of virtual neurons (VNs). To fit the ECAP amplitudes we assign a suitable weight to each VN related with the probability of an ANF to be excited. This probability is expressed by a cumulative beta distribution parameterized by two shape parameters that are calculated by means of a differential evolution algorithm (DE). Being the weights function of the current density, any change in the design of the CI affecting the current density produces changes in the weights and, therefore, in the simulated ECAP, which confers to our model a predictive capacity. The results of the validation with ECAP data from two patients are presented, achieving a satisfactory fit of the experimental data with those provided by the proposed computational model.

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.

The Superiority of the Otolith System.

BACKGROUND: The peripheral vestibular end organ is considered to consist of semi-circular canals (SCC) for detection of angular accelerations and the otoliths for detection of linear accelerations. However, otoliths being phylogenetically the oldest part of the vestibular sensory organs are involved in detection of all motions. SUMMARY: This study elaborates on this property of the otolith organ, as this concept can be of importance for the currently designed vestibular implant devices. Key Message: The analysis of the evolution of the inner ear and examination of clinical examples shows the robustness of the otolith system and inhibition capacity of the SCC. The otolith system must be considered superior to the SCC system as illustrated by evolution, clinical evidence, and physical principles.

Chronic Electrical Stimulation of the Otolith Organ: Preliminary Results in Humans with Bilateral Vestibulopathy and Sensorineural Hearing Loss.

INTRODUCTION: Bilateral vestibulopathy is an important cause of imbalance that is misdiagnosed. The clinical management of patients with bilateral vestibular loss remains difficult as there is no clear evidence for an effective treatment. In this paper, we try to analyze the effect of chronic electrical stimulation and adaptation to electrical stimulation of the vestibular system in humans when stimulating the otolith organ with a constant pulse train to mitigate imbalance due to bilateral vestibular dysfunction (BVD). METHODS: We included 2 patients in our study with BVD according to Criteria Consensus of the Classification Committee of the Bárány Society. Both cases were implanted by using a full-band straight electrode to stimulate the otoliths organs and simultaneously for the cochlear stimulation we use a perimodiolar electrode. RESULTS: In both cases Vestibular and clinical test (video head impulse test, videonistagmography cervical vestibular evoked myogenic potentials, cVEMP and oVEMP), subjective visual vertical test, computerized dynamic posturography, dynamic gait index, Time UP and Go test and dizziness handicap index) were performed. Posture and gait metrics reveal important improvement if compare with preoperartive situation. Oscillopsia, unsteadiness, independence and quality of life improved to almost normal situation. DISCUSSION/CONCLUSION: Prosthetic implantation of the otolith organ in humans is technically feasible. Electrical stimulation might have potential effects on balance and this is stable after 1 year follow-up. This research provides new possibilities for the development of vestibular implants to improve gravito-inertial acceleration sensation, in this case by the otoliths stimulation.

Single-sided deafness and cochlear implantation in congenital and acquired hearing loss in children.

OBJECTIVE: To determine the audiological and clinical results of cochlear implantation in children below the age of 12 years old with congenital and acquired single-sided deafness. DESIGN: Observational, descriptive, transversal study. MAIN OUTCOME MEASURES: Speech reception thresholds, Cortical responses, Auditory Lateralization Test and SSQ questionnaire. PARTICIPANTS: Children < 12 implanted for congenital or acquired SSD. RESULTS: All the children with congenital SSD showed positive cortical responses. Positive results were obtained in the Auditory Lateralization Test for the following modalities: 0º, 45º and 90º. With respect to the Speech Test, the children with acquired SSD showed the following results: 92% and 100% in recognition and 48% and 68% (Azimuth modalities), Signal CI side 52% and 68% and Signal normal hearing side 44% - 60% (p < 0.05). In both group the processor was used for 6-12 hours. With respect to the SSQ questionnaire results, the parents were more satisfied within the post-operative period than within the pre-operative period (P<0.001). CONCLUSIONS: Cochlear implant provides children with congenital SSD with significant audiological and subjective benefits. Children with congenital SSD and implanted after a longer period may not have an important benefit (binaural) although other bilateral effects can be achieved. Children with post-lingual unilateral deafness and after a short period of hearing deprivation probably integrated the normal acoustic hearing with the cochlear implant electrical signal and showed binaural benefits.

One-Year Results for Patients with Unilateral Hearing Loss and Accompanying Severe Tinnitus and Hyperacusis Treated with a Cochlear Implant.

OBJECTIVE: To show that patients with unilateral hearing loss (UHL), with one ear fulfilling cochlear implant (CI) indication criteria, and an additional severe tinnitus handicap can be treated effectively with a CI. METHOD: A prospective multi-centre study was conducted in five Spanish centres. Sixteen adult patients with UHL and a mean Tinnitus Handicap Inventory (THI) score of at least 58 were implanted. The study design included repeated within-subject measures of quality of life (Health Utility Index Mark 3 [HUI3]), tinnitus (THI, Visual Analogue Scale [VAS] on tinnitus loudness), hearing (Speech, Spatial, and Qualities of Hearing Scale- [SSQ]), and hyperacusis (Test de Hipersensibilidad al Sonido [THS]) up to 12 months after the initial CI fitting. RESULTS: Group data showed significant subjective benefit from CI treatment: the preoperative HUI3 total utility score of 0.45 went up to 0.57 at 6 months and 0.63 at 12 months; the preoperative THI total score of 75 decreased to 40 at 6 months and 35 at 12 months. The preoperative tinnitus loudness VAS score of 8.2 decreased to 2.4 at 6 months and 2.2 at 12 months with the implant "On" and to 6.7 at 6 months and 6.5 at 12 months with the implant "Off." The preoperative THS total score of 26 decreased to 17 at 12 months. The preoperative SSQ total score of 4.2 increased to 5.1 at 6 months and 6.3 at 12 months. No unanticipated adverse events were reported during the study period. At 12 months after CI activation all subjects (except 1 subject who used the device 6 days a week) wore their devices all day and every day. The primary reason for CI use was split evenly between tinnitus suppression (n = 6) and both hearing and tinnitus (n = 6). CONCLUSION: A CI should be considered as a treatment option in patients with UHL and a concomitant severe tinnitus handicap. However, appropriate counselling of candidates on the anticipated risks, benefits, and limitations that are inherent to cochlear implantation is imperative.

Imaging evaluation of electrode placement and effect on electrode discrimination on different cochlear implant electrode arrays.

OBJECTIVE: The aim of the present study is to evaluate the effect of electrode discrimination based on electrode to modiolus distance in different cochlear implant models, using image information to estimate the outcomes after an implantation on electrode discrimination METHODS: A descriptive prospective randomized study performed during 16 months. A psychoacoustic platform was used to evaluate patients' electrode discrimination capabilities of patients. For the acquisition of the images, a cone beam computed tomography was used to assess postcochlear implantation of electrodes' position. We considered two other new measurements: the intracochlear position index, which indicates how far is the electrode from the modiolar wall, and the homogeneity factor (HF), which provides us with information about the distance between the electrodes and the modiolus RESULTS: 21 postlingually deaf adults showing different CI models [CI522 (n = 7), CI512 (n = 7), and CI532 (n = 7)] that corresponded to the lateral and perimodiolar array electrodes. The average success rate of the CI522 group was 47%, of the CI512 group was 48%, and of the CI532 group was 77%. There is statistically significant difference between groups CI532-CI522 (p = 0.0033) and CI532-CI512 (p = 0.0027) CONCLUSION: The Nucleus CI532 offers a better perimodiolar placement. HF and IPI measurements provide information about the electrodes location inside the cochlea, being related to electrode discrimination.

Hearing Preservation with the Slim Modiolar Electrode Nucleus CI532® Cochlear Implant: A Preliminary Experience.

As the indications for cochlear implant have expanded to include younger patients and individuals with greater degrees of residual hearing, increasing emphasis has been placed on atraumatic surgery and the preservation of the cochlear structure. Here, a descriptive prospective randomized study was performed. It was shown that residual hearing preservation is possible 12 months postoperatively with an atraumatic perimodiolar flexible electrode array CI532® (Cochlear Ltd, Sydney, Australia). Residual hearing preservation, considered as < 15 dB, was obtained in 70% of the cases. Better clinical outcomes and performance could be obtained compared with the previous perimodiolar CI512®, but further research and a longer follow-up are necessary to verify the impact of outcomes.

Health-Related Quality of Life in Adult Cochlear Implant Users: A Descriptive Observational Study.

Cochlear implantation has a significant impact on patients' social life, performance of activities, and self-esteem. The objective of this retrospective study was to assess the health-related quality of life of cochlear implant users aged under and over 60 years by a self-report using the Glasgow Health Status Inventory and the Abbreviated Profile of Hearing Aid Benefit. It was observed that quality of life values increased very rapidly straight after implantation regardless of age. Bilateral cochlear implant users showed better results in environments with background noise and in a reverberant room than unilateral cochlear implant users. Quality of life improved independently of hearing performance benefits for patients over 60 years at implantation.

Air traffic controllers' long-term speech-in-noise training effects: A control group study.

INTRODUCTION: Speech perception in noise relies on the capacity of the auditory system to process complex sounds using sensory and cognitive skills. The possibility that these can be trained during adulthood is of special interest in auditory disorders, where speech in noise perception becomes compromised. Air traffic controllers (ATC) are constantly exposed to radio communication, a situation that seems to produce auditory learning. The objective of this study has been to quantify this effect. SUBJECTS AND METHODS: 19 ATC and 19 normal hearing individuals underwent a speech in noise test with three signal to noise ratios: 5, 0 and -5 dB. Noise and speech were presented through two different loudspeakers in azimuth position. Speech tokes were presented at 65 dB SPL, while white noise files were at 60, 65 and 70 dB respectively. RESULTS: Air traffic controllers outperform the control group in all conditions [P<0.05 in ANOVA and Mann-Whitney U tests]. Group differences were largest in the most difficult condition, SNR=-5 dB. However, no correlation between experience and performance were found for any of the conditions tested. The reason might be that ceiling performance is achieved much faster than the minimum experience time recorded, 5 years, although intrinsic cognitive abilities cannot be disregarded. DISCUSSION: ATC demonstrated enhanced ability to hear speech in challenging listening environments. This study provides evidence that long-term auditory training is indeed useful in achieving better speech-in-noise understanding even in adverse conditions, although good cognitive qualities are likely to be a basic requirement for this training to be effective. CONCLUSION: Our results show that ATC outperform the control group in all conditions. Thus, this study provides evidence that long-term auditory training is indeed useful in achieving better speech-in-noise understanding even in adverse conditions.

Cochlear implants as a treatment option for unilateral hearing loss, severe tinnitus and hyperacusis.

Tinnitus is an incapacitating condition commonly affecting cochlear implant (CI) candidates. The aim of this clinical study is to assess the long-term effects of CI treatment in patients with severe-to-profound, sensorineural, unilateral hearing loss (UHL) and incapacitating tinnitus. We performed a prospective Cochlear™ company-sponsored multicentre study in five Spanish centres. Sixteen patients with UHL and incapacitating tinnitus, which was indicated by a Tinnitus Handicap Inventory (THI) score >58%, received a Nucleus® CI in their deaf ear. The study design includes repeated within-subject measures on hearing, tinnitus, hyperacusis and quality of life up to 12 months after initial CI fitting. In addition to hearing loss and tinnitus, all patients suffered from hyperacusis. Most patients had a sudden hearing loss and received a CI within 2 years after their hearing loss. Preliminary 6-month, post-CI activation data of 13 subjects showed that the majority of patients perceived a subjective benefit from CI treatment, which was assessed using the THI, a Visual Analogue Scale of tinnitus loudness/annoyance and the Speech, Spatial and Qualities of Hearing Scale. Preliminary 12-month data of 7 subjects showed that most patients also perceived a degree of relief from their hyperacusis. One patient showed no improvements in any of the applied scales, which could be explained by partial insertion of the electrode due to obstruction of the cochlea by otosclerosis. In conclusion, CI can successfully be used in the treatment of UHL patients with accompanying severe tinnitus and hyperacusis. Implantation resulted in hearing benefits and a durable relief from tinnitus and hyperacusis in the majority of patients. These findings support the hypothesis that pathophysiological mechanisms after peripheral sensorineural hearing loss are at least partly reversible when hearing is restored with a CI.

A comparative study on speech in noise understanding with a direct acoustic cochlear implant in subjects with severe to profound mixed hearing loss.

The aim of this study was to investigate the efficacy of a direct acoustic cochlear implant (DACI) for speech understanding in noise in patients suffering from severe to profound mixed hearing loss (MHL) due to various etiologies compared to the preoperative best-aided condition. The study was performed at five tertiary referral centers in Europe (Belgium, Germany, Poland and Spain). Nineteen adult subjects with severe to profound MHL due to (advanced) otosclerosis, ear canal fibrosis, chronic otitis media, tympanosclerosis or previous cholesteatoma were implanted with a DACI (Codacs™ Investigational Device) combined with a conventional stapes prosthesis. Unaided and aided speech reception scores in quiet and in noise, preoperative and postoperative air and bone conduction thresholds and aided and unaided sound field thresholds were measured prospectively during the study. Subjective benefit analysis was determined through the Abbreviated Profile of Hearing Aid Benefit questionnaire. Quality of life was measured by the Health Utilities Index. All subjects were fitted preoperatively with hearing aids and/or a bone conduction implant on a headband before DACI implantation. This allows direct comparison between different hearing rehabilitation solutions. The mean speech reception threshold in noise improved significantly by 7.9 dB signal-to-noise ratio (SNR) after activation of the DACI compared to the preoperative best-aided condition. For all 19 subjects, a mean postoperative aided speech reception threshold of 2.6 dB SNR (standard deviation: 8.3 dB) was measured. On average, no significant shift in the bone conduction thresholds was noted 4-5 months after implantation. A mean sound field threshold improvement of 46 and 16 dB was measured compared to the preoperative unaided and best-aided condition, respectively. Speech perception tests in quiet showed a mean improvement of the word recognition scores by 65 and 48% at 65 dB SPL compared to the preoperative unaided and best-aided condition, respectively. In summary, DACI provides an effective improvement of the speech perception in noise compared to the best-aided condition in subjects suffering from severe to profound MHL.

Stimulation Crosstalk Between Cochlear And Vestibular Spaces During Cochlear Electrical Stimulation.

OBJECTIVES: Possible beneficial "crosstalk" during cochlear implant stimulation on otolith end organs has been hypothesized. The aim of this case-control study is to analyze the effect of electrical cochlear stimulation on the vestibule (otolith end-organ), when using a cochleo-vestibular implant, comparing vestibular stimulation (VI) and cochlear stimulation (CI). METHODS: Four patients with bilateral vestibulopathy were included. A double electrode array research implant was implanted in all cases. Dynamic Gait Index (DGI), VOR gain measured by using vestibular head impulse test (vHIT), acoustic cervical myogenic responses (cVEMP) recordings, and electrical cVEMP were used in all cases. Trans-impedance Matrix (TIM) analysis was used to evaluate the current flow from the cochlea to the vestibule. RESULTS: While patients did not have any clinical vestibular improvement with the CI stimulation alone, gait metrics of the patients revealed improvement when the vestibular electrode was stimulated. The average improvement in the DGI was 38% when the vestibular implant was activated, returning to the normal range in all cases. Our findings suggest that any current flow from the cochlear space to the otolith organs was insufficient for effective cross-stimulation. The functional results correlated with the data obtained in TIM analysis, confirming that there is no current flow from the cochlea to the vestibule. CONCLUSION: The only way to produce effective electrical otolith end-organ stimulation, demonstrated with this research implant, is by direct electrical stimulation of the otolith end organs. No effective cross-stimulation was found from cochlear electrode stimulation. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:2349-2355, 2024.

Using Pupillometry to Evaluate Balance in Patients Implanted with a Cochleo-Vestibular Implant.

Maintaining balance comes naturally to healthy people. In subjects with vestibulopathy, even when compensated, and especially if it is bilateral, maintaining balance requires cognitive effort. Pupillometry is an established method of quantifying cognitive effort. Background/Objectives: We hypothesized that pupillometry would be able to capture the increased effort required to maintain posture in subjects with bilateral vestibulopathy in increasingly difficult conditions. Additionally, we hypothesized that the cognitive workload during balance tasks, indexed by pupil size, would decrease with the activation of the BionicVEST cochleo-vestibular implants. Methods: Subjects with a cochleo-vestibular implant as of March 2023 were recruited, excluding those with ophthalmological issues that precluded pupillometry. Pupillometry was performed using a validated modified videonystagmography system. Computed dynamic posturography and a Modified Clinical Test of Sensory Integration on Balance were performed while the pupil was recorded. Tests were first performed after 24 h of deactivating the vestibular component of the implant. Thereafter, it was reactivated, and after 1 h of rest, the tests were repeated. The pupil recording was processed using custom software and the mean relative pupil diameter (MRPD) was calculated. Results: There was an average of 10.7% to 24.2% reduction in MRPD when the vestibular implant was active, with a greater effect seen in tasks of moderate difficulty, and lesser effect when the task was easy or of great difficulty. Conclusions: Despite technical challenges, pupillometry appears to be a promising method of quantifying the cognitive effort required for maintaining posture in subjects with bilateral vestibulopathy before and after vestibular implantation.

Genotyping of rams based on melatonin receptor 1A gene polymorphisms: a tool in sire selection?

Context Several polymorphisms in the melatonin receptor 1A gene (MTNR1A ) have been related to reproductive performance in ovine. Aims To investigate the effect of the Rsa I and Mnl I polymorphisms on ram seminal quality. Methods Eighteen Rasa Aragonesa rams were genotyped for the Rsa I (C/C, C/T, T/T) and Mnl I (G/G, G/A, A/A) allelic variants of the MTNR1A gene. Individual ejaculates were analysed once a month throughout the whole year. Sperm motility, morphology, membrane integrity, levels of reactive oxygen species (ROS), phosphatidylserine (PS) inversion, DNA fragmentation and capacitation status were assessed. The effect of the season and polymorphisms on seminal quality was evaluated by mixed ANOVA. Key results Both polymorphisms had an effect on membrane integrity and viable spermatozoa with low levels of ROS and without PS translocation, and Rsa I also on motile and DNA-intact spermatozoa. An interaction between both polymorphisms was found, pointing to a negative effect on seminal quality of carrying the T or A allele in homozygosity. Differences were higher in the reproductive than in the non-reproductive season. Conclusions Mutations substituting C by T and G by A at Rsa I and Mnl I polymorphic sites, respectively, in the MTNR1A gene in rams could decrease the seminal quality. Implications Genotyping of rams based on melatonin receptor 1A could be a powerful tool in sire selection.

Cognitive processing speed improvement after cochlear implantation.

Background: Untreated hearing loss has an effect on cognition. It is hypothesized that the additional processing required to compensate for the sensory loss affects the cognitive resources available for other tasks and that this could be mitigated by a hearing device. Methods: The impact on cognition of cochlear implants (CIs) was tested in 100 subjects, ≥60 years old, with bilateral moderately-severe to profound post linguistic deafness using hearing aids. Data was compared pre and 12 and 18 months after cochlear implantation for the speech spatial qualities questionnaire, Mini Mental State Examination (MMSE), Trail making test B (TMTB) and digit symbol coding (DSC) from the Wechsler Adult Intelligence Scale version IV and finally the timed up and go test (TUG). Subjects were divided into young old (60-64), middle old (65-75) and old old (75+) groups. Cognitive test scores and times were standardized according to available normative data. Results: Hearing significantly improved pre- to post-operatively across all age groups. There was no change post-implant in outcomes for TMTB, TUG or MMSE tests. Age-corrected values were within normal expectations for all age groups for the TUG and MMSE. However, DSC scores and TMTB times were worse than normal. There was a significant increase in DSC scores between baseline and 12-months for 60- to 64-year-olds (t[153] = 2.608, p = 0.027), which remained at 18 months (t[153] = 2.663, p = 0.023). Discussion: The improved attention and processing speed in the youngest age group may be a consequence of reallocation of cognitive resources away from auditory processing due to greatly improved hearing. The oldest age group of participants had cognition scores closest to normal values, suggesting that only the most able older seniors tend to come forward for a CI. Severe to profoundly deaf individuals with hearing aids or cochlear implants were still poorer than age-equivalent normally hearing individuals with respect to cognitive flexibility, attention, working memory, processing speed and visuoperceptual functions. Due to a lack of data for the TUG, TMTB and DSC in the literature for hearing impaired individuals, the results reported here provide an important set of reference data for use in future research.

European multi-centre study of the Nucleus Hybrid L24 cochlear implant.

OBJECTIVES: To investigate the preservation of residual hearing in subjects who received the Nucleus Hybrid L24 cochlear implant. To investigate the performance benefits up to one year post-implantation in terms of speech recognition, sound quality, and quality of life. DESIGN: Prospective, with sequential enrolment and within-subject comparisons. Post-operative performance using a Freedom Hybrid sound processor was compared with that of pre-operative hearing aids. STUDY SAMPLE: Sixty-six adult hearing-impaired subjects with bilateral severe-to-profound high frequency hearing loss. RESULTS: Group median increase in air-conduction thresholds in the implanted ear for test frequencies 125-1000 Hz was < 15 dB across the population; both immediately and one year post-operatively. Eighty-eight percent of subjects used the Hybrid processor at one year post-op. Sixty-five percent of subjects had significant gain in speech recognition in quiet, and 73% in noise (≥ 20 percentage points/2 dB SNR). Mean SSQ subscale scores were significantly improved (+ 1.2, + 1.3, + 1.8 points, p < 0.001), as was mean HUI3 score (+ 0.117, p < 0.01). Combining residual hearing with CI gave 22-26 %age points mean benefit in speech recognition scores over CI alone (p < 0.01). CONCLUSIONS: Useful residual hearing was conserved in 88% of subjects. Speech perception was significantly improved over preoperative hearing aids, as was sound quality and quality of life.

Recent Advances in the Diagnosis and Treatment of Vestibular Disorders.

Vestibular medicine "embraces a wide approach to the potential causes of vestibular symptoms, acknowledging that vertigo, dizziness, and unsteadiness are non-specific symptoms that may arise from a broad spectrum of disorders, spanning from the inner ear to the brainstem, cerebellum and supratentorial cerebral networks, to many disorders beyond these structures" [...].