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.

COVID-19 era: Hearing handicaps behind face mask use in hearing aid users.

BACKGROUND: The aim of this study was to assess the effect on speech perception and lack of hearing devices gain with surgical masks worn in hearing aid users. METHODS: This prospective cohort study enrolled consecutive patients between November 2020 and February 2021 in a tertiary care medical center from Spain. Fifty-five subjects have been included, 10 as control group, with normal hearing, and 45 patients with sensory-neural hearing loss and hearing aid users, ranging in age between 31 and 83 years old, and were recruited randomized in 4 months. Appropriate test was done previously to check adequate functioning from devices and suitable adaptation. Control group had no hearing impairment neither otologic disease. RESULTS: Disyllabic test in quiet get worse with face mask with a significant difference and stronger impact in noisy background. Age made no difference. Adding lipreading speech perception improved by 95.1 % for younger subjects (<50 years of age) and 91.2% for older subjects (>50 years of age). In the control sample, there was no differences in any condition. CONCLUSION: Despite advantages of wearing mask in preventing coronavirus disease 2019 spread, we must consider that they have also drawbacks for some groups like hearing aid users. In this research, we have not observed high frequencies perception decrease with surgical masks worn, but there was reduction in speech perception, most notably in hearing aids wearers in noisy environment.

Dynamic Visual Acuity Results in Otolith Electrical Stimulation in Bilateral Vestibular Dysfunction.

(1) Background. Patients with bilateral vestibular disease (BVD) experience oscillopsia with a detriment to visual acuity (VA). This VA is driven mainly by the VOR that has two components: rotational and translational. VA can be tested by using dynamic visual acuity (DVA) on a treadmill because both systems are activated. The aim of this study is to compare VA before and after chronic electrical stimulation of the otolith organ. (2) Materials and Method. Five patients suffering from bilateral vestibular dysfunction (BVD), previously implanted with a new vestibular implant prototype, were included in this study with the aim to check VA with and without vestibular implant use (W and W/O) in static, 2 km/h and 4 km/h walking situations. DVAtreadmill was measured on a treadmill with a dynamic illegible E (DIE) test in static and dynamic conditions (while walking on the treadmill at 2 and 4 km/h). The DVA score was registered in a logarithm of the minimum angle of resolution (LogMAR) for each speed. In addition, every patient completed the oscillopsia severity questionnaire (OSQ) and video head impulse test (vHIT) before and after activation of the vestibular implant. (3) Results. The analysis shows a significant difference in OSQ scores and DVA with an improvement in dynamic conditions. Organized corrective saccades during the use of a vestibular implant with no changes in gain were also detected in the video head impulse tests (vHIT). (4) Conclusion. The vestibular implant with otolithic stimulation offers changes in the response of DVA, which makes this paper one of the first to address the possible restoration of it. It is not possible to rule out other contributing factors (presence of covert saccades, somatosensory system, …). More work seems necessary to understand the neurophysiological basis of these findings, but this implant is added as a therapeutic alternative for the improvement of oscillopsia.

Assessing the Placement of the Cochlear Slim Perimodiolar Electrode Array by Trans Impedance Matrix Analysis: A Temporal Bone Study.

New cochlear implant (CI) electrode arrays provide softer insertion dynamics; however, due to their high flexibility, the possibilities of fold-overs or intraoperative displacements must be taken into account. The position of each individual electrode can only be determined by using high-resolution computed tomography or cone-beam CT. The trans-impedance matrix test (TIM) is an electrophysiological method based on electric field imaging that can provide images of electrode position and electrode folding. OBJECTIVE: In this experimental research, we evaluated the result of TIM as a method of monitoring cochlear insertion for a precurved slim modiolar electrode array in fresh human temporal bones by analyzing the transimpedance matrix patterns and their correlation with electrode position using high-resolution computed tomography. MATERIAL AND METHODS: Sixteen slim modiolar electrode arrays were inserted into eight fresh Human Temporal Bones. Eight electrodes were inserted according to the correct methodology of insertion, and eight were intentionally folded over. After all insertions, a trans-impedance matrix analysis and a Cone Beam CT (CBCT) were performed in each temporal bone. RESULTS: If we correlated the TIM patterns with the radiological electrode position, we observed that better electrode intracochlear positions indicated more "homogeneous" TIM patterns (intracochlear voltage dropped monotonically as the distance between stimulation and recording contact increased, both toward the apex and toward the base). A correlation where fold-over was detected in the TIM results was found in all eight temporal bone radiological findings. CONCLUSIONS: Trans-Impedance Matrix patterns were correlated with the radiological CI electrode position. When a tip fold-over appeared, a matrix with a secondary ridge in addition to the primary ridge was observed in all cases. TIM can be an effective method in the control of electrode positioning.

Tinnitus suppression with electrical stimulation in adults: long-term follow-up.

Objectives: To investigate the long-term effects of cochlear implants as a treatment for patients with severe to profound neurosensory loss associated with severe tinnitus. Methods: Prospective study in 17 adult patients with severe to profound sensorineural hearing loss associated with severe tinnitus, indicated with a Tinnitus Handicap Inventory (THI) score ≥ 58%, and hyperacusis. Measures were made on hearing, tinnitus, hyperacusis and quality of life up to 5 years after activation of the sound processor of the cochlear implant. It was evaluated by using the disyllabic test, THI, visual analogue scale and Glasgow Benefit Inventory questionnaire. Results: 60 months after cochlear implantation, improvements in loudness and discomfort of tinnitus, speech discrimination and hyperacusis were observed. Subjects perceive an important subjective benefit upon receiving the cochlear implant. Conclusions: Cochlear implants can be used as treatment for patients with severe to profound sensorineural hearing loss associated with severe tinnitus and hyperacusis with long-term benefits on quality of life and lasting relief of tinnitus.

MAMMALS IN PORTUGAL: A data set of terrestrial, volant, and marine mammal occurrences in Portugal.

Mammals are threatened worldwide, with ~26% of all species being included in the IUCN threatened categories. This overall pattern is primarily associated with habitat loss or degradation, and human persecution for terrestrial mammals, and pollution, open net fishing, climate change, and prey depletion for marine mammals. Mammals play a key role in maintaining ecosystems functionality and resilience, and therefore information on their distribution is crucial to delineate and support conservation actions. MAMMALS IN PORTUGAL is a publicly available data set compiling unpublished georeferenced occurrence records of 92 terrestrial, volant, and marine mammals in mainland Portugal and archipelagos of the Azores and Madeira that includes 105,026 data entries between 1873 and 2021 (72% of the data occurring in 2000 and 2021). The methods used to collect the data were: live observations/captures (43%), sign surveys (35%), camera trapping (16%), bioacoustics surveys (4%) and radiotracking, and inquiries that represent less than 1% of the records. The data set includes 13 types of records: (1) burrows | soil mounds | tunnel, (2) capture, (3) colony, (4) dead animal | hair | skulls | jaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8), observation in shelters, (9) photo trapping | video, (10) predators diet | pellets | pine cones/nuts, (11) scat | track | ditch, (12) telemetry and (13) vocalization | echolocation. The spatial uncertainty of most records ranges between 0 and 100 m (76%). Rodentia (n =31,573) has the highest number of records followed by Chiroptera (n = 18,857), Carnivora (n = 18,594), Lagomorpha (n = 17,496), Cetartiodactyla (n = 11,568) and Eulipotyphla (n = 7008). The data set includes records of species classified by the IUCN as threatened (e.g., Oryctolagus cuniculus [n = 12,159], Monachus monachus [n = 1,512], and Lynx pardinus [n = 197]). We believe that this data set may stimulate the publication of other European countries data sets that would certainly contribute to ecology and conservation-related research, and therefore assisting on the development of more accurate and tailored conservation management strategies for each species. There are no copyright restrictions; please cite this data paper when the data are used in publications.

A food web approach reveals the vulnerability of biocontrol services by birds and bats to landscape modification at regional scale.

Pest control services provided by naturally occurring species (the so-called biocontrol services) are widely recognized to provide key incentives for biodiversity conservation. This is particularly relevant for vertebrate-mediated biocontrol services as many vertebrate species are of conservation concern, with most of their decline associated to landscape modification for agricultural purposes. Yet, we still lack rigorous approaches evaluating landscape-level correlates of biocontrol potential by vertebrates over broad spatial extents to better inform land-use and management decisions. We performed a spatially-explicit interaction-based assessment of potential biocontrol services in Portugal, using 1853 pairwise trophic interactions between 78 flying vertebrate species (birds and bats) and 53 insect pests associated to two widespread and economically valuable crops in the Euro-Mediterranean region, olive groves (Olea europaea subsp. europaea) and vineyards (Vitis vinifera subsp. vinifera). The study area was framed using 1004 square cells, each 10 × 10 km in size. Potential biocontrol services were determined at all those 10 × 10 km grid-cells in which each crop was present as the proportion of the realized out of all potential pairwise interactions between vertebrates and pests. Landscape correlates of biocontrol potential were also explored. Our work suggests that both birds and bats can effectively provide biocontrol services in olive groves and vineyards as they prey many insect pest species associated to both crops. Moreover, it demonstrates that these potential services are impacted by landscape-scale features and that this impact is consistent when evaluated over broad spatial extents. Thus, biocontrol potential by vertebrates significantly increases with increasing amount of natural area, while decreases with increasing area devoted to target crops, particularly olive groves. Overall, our study highlights the suitability of our interaction-based approach to perform spatially-explicit assessments of potential biocontrol services by vertebrates at local spatial scales and suggest its utility for integrating biodiversity and ecosystem services in conservation planning over broad spatial extents.

Cochlear Implants in Single-Sided Deafness. Comparison Between Children and Adult Populations With Post-lingually Acquired Severe to Profound Hearing Loss.

Objective: To determine audiological and clinical results of cochlear implantation (CI) comparing two populations with single-sided deafness (SSD): post-lingually deaf children between 6 and 12 years of age, and post-lingually deaf adults, in order to evaluate the effect of CI in different age groups. Design: Retrospective case review. Setting: Tertiary clinic. Patients and Method: Twenty-three children and twenty-one adult patients that were candidates for CI with single-side deafness were included. In all cases we evaluate: Speech perception thresholds; disyllabic words test (65 dB SPL) were performed in the modalities S0-SCI-SNH and Auditory Lateralization Test. The Speech, Spatial, and Qualities of Hearing Scale (SSQ) questionnaire was also used. All results were obtained after 12 months of CI activation. Results: In children, the most common etiology was idiopathic sensory-neural hearing loss. They showed positive results in the Auditory Lateralization Test. In the Speech Test, word recognition in noise improved from 2% preoperatively to 61.1% at a mean follow-up of 1 year (S0 condition) in children [test with signal in CI side 60% and signal normal hearing side (plugged) 31%]. The processor was used for >12 h in all cases. With respect to the SSQ questionnaire, parents were more satisfied within the postoperative period than within the preoperative period. For adults, the most common etiology was idiopathic sudden sensorineural hearing loss (SNHL). Positive results in the Auditory Lateralization Test were found. With respect to the Speech Test in quiet conditions: Word recognition in noise improved from 5.7% preoperatively to 71.8% at a mean follow-up of 1 year [test with signal in CI side 68% and signal normal hearing side (plugged) 41%]. The processor was used for >12 h. In the SSQ questionnaire, the post-operative results showed a beneficial effect of the CI. No adverse events were reported during the study period. No differences were found between children and adults in all tests in this study. Conclusions: Cochlear implantation in post-lingually deaf adults and children with SSD can achieve a speech perception outcome comparable with CI in conventional candidates. Improvements in spatial hearing were also observed. Careful patient selection and counseling regarding potential benefits are important to optimize outcomes.

Transcutaneous Osseo-integrated Auditory Devices: Analysis of Two Different Implants in Adults With Different Audiological Inclusion Criteria.

OBJECTIVE: To determine and compare audiological and speech/language discrimination results in patients with osteo-integrated auditory devices, by comparing two different systems including different audiological indications in adult population. STUDY DESIGN: Descriptive and analytic, cross-sectional, cohort, and retrospective case review. SETTING: Tertiary referral center. MATERIALS AND METHODS: Fifty patients >14 years old, with conductive, mixed, or unilateral sensorineural hearing loss were compared. The variables studied were the following: pure tone audiometry results, air-bone gap, and the percentage of speech/language discrimination using Disyllabic Word Test. The patients were tested preoperative and 12 months after surgical procedure. Subsequently, a comparative analysis of the both systems was carried out. RESULTS: With both implants, pure tone audiometry results and the difference in auditory thresholds and between the air-bone gap improved significantly. Speech discrimination increased significantly after implantation too. A significant difference was observed after implantation of both devices. Patients implanted with one of the implants showed better audiological results, but no significant differences were found with the other device. So, it was shown that the type of device and the type of hearing loss have no influence on the audiological results or complications. CONCLUSION: Both implants represent a good choice for audiological rehabilitation in patients with transmissive hearing loss, mixed hearing loss, or unilateral sensorineural hearing loss with a high success and low complication rates.

Differences in Vestibular-Evoked Myogenic Potential Responses by Using Cochlear Implant and Otolith Organ Direct Stimulation.

Objective: Several studies have demonstrated the possibility to obtain vestibular potentials elicited with electrical stimulation from cochlear and vestibular implants. The objective of this study is to analyze the vestibular-evoked myogenic potentials (VEMPs) obtained from patients implanted with cochlear and vestibulo-cochlear implant. Material and Methods: We compared two groups: in the first group, four cochlear implant (CI) recipients with present acoustic cVEMPs before CI surgery were included. In the second group, three patients with bilaterally absent cVEMPs and bilateral vestibular dysfunction were selected. The latter group received a unilateral cochleo-vestibular implant. We analyze the electrically elicited cVEMPs in all patients after stimulation with cochlear and vestibular electrode array stimulation. Results: We present the results obtained post-operatively in both groups. All patients (100%) with direct electrical vestibular stimulation via the vestibular electrode array had present cVEMPs. The P1 and N1 latencies were 11.33-13.6 ms and 18.3-21 ms, respectively. In CI patients, electrical cVEMPs were present only in one of the four subjects (25%) with cochlear implant ("cross") stimulation, and P1 and N1 latencies were 9.67 and 16.33, respectively. In these patients, the responses present shorter latencies than those observed acoustically. Conclusions: Electrically evoked cVEMPs can be present after cochlear and vestibular stimulation and suggest stimulation of vestibular elements, although clinical effect must be further studied.

[Macrolides as a possible cause of hearing loss in childhood]. / Macrólidos como posible causa de hipoacusia en la infancia.

INTRODUCTION: Idiopathic sudden hearing loss (SHL) is a relatively frequent entity in the adult population with unk nown cause in most cases. There are few studies in pediatric age and its diagnosis and management are a challenge for health professionals. OBJECTIVE: To relate macrolide therapy as a causal agent of sudden hearing loss in pediatric patients. CLINICAL CASE: 3-year-old girl with no relevant pathological history, with normal neonatal hearing screening and age-appropriate language development. She consulted due to an upper airway infectious process, treated on an outpatient basis with azithromycin for 3 days. One week later, she developed bilateral hearing loss, confirmed with Brainstem Auditory Evoked Potentials (BAEP), and started treatment with oral methylprednisolone and intratympanic corticosteroids. During treatment, imaging, laboratory, and genetic studies were performed, ruling out other causes of SHL, so the recent use of macrolides was considered as a possible diagnosis. As no clinical improvement was observed 6 weeks after the treatment, confirmed by the absence of response in the steady-state auditory evoked potentials and BAEP, simultaneous bilateral cochlear implant surgery was carried out. Four years after surgery, the patient showed good speech-language develop ment and adequate school performance. CONCLUSIONS: Ototoxicity is a cause that must be considered in the case of SHL in childhood. A multidisciplinary approach will allow effective treatment in these patients, in which early management with an adequate hearing aid will restore hearing and achieve adequate speech development and linguistic competence.

Evaluation of the Curing of Adhesive Systems by Rheological and Thermal Testing.

The analysis of thermal processes associated to the curing of adhesives and the study of mechanical behavior once cured, provide key information to choose the best option for any specific application. The proposed methodology for the curing characterization, based on thermal analysis and rheology, is described through the comparison of three commercial adhesives. The experimental techniques used here are Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Rheology. TGA provides information about the thermal stability and filler content, DSC allows the evaluation of some thermal events associated to the cure reaction and to thermal changes of the cured material when subjected to temperature changes. Rheology complements the information of the thermal transformations from a mechanical point of view. Thus, the curing reaction can be tracked through the elastic modulus (mainly the storage modulus), the phase angle and the gap. In addition, it is also shown that although DSC is of no use to study the curing of moisture curable adhesives, it is a very convenient method to evaluate the low temperature glass transition of amorphous systems.

Electrical Vestibular Stimulation in Humans: A Narrative Review.

BACKGROUND: In patients with bilateral vestibulopathy, the regular treatment options, such as medication, surgery, and/or vestibular rehabilitation, do not always suffice. Therefore, the focus in this field of vestibular research shifted to electrical vestibular stimulation (EVS) and the development of a system capable of artificially restoring the vestibular function. Key Message: Currently, three approaches are being investigated: vestibular co-stimulation with a cochlear implant (CI), EVS with a vestibular implant (VI), and galvanic vestibular stimulation (GVS). All three applications show promising results but due to conceptual differences and the experimental state, a consensus on which application is the most ideal for which type of patient is still missing. SUMMARY: Vestibular co-stimulation with a CI is based on "spread of excitation," which is a phenomenon that occurs when the currents from the CI spread to the surrounding structures and stimulate them. It has been shown that CI activation can indeed result in stimulation of the vestibular structures. Therefore, the question was raised whether vestibular co-stimulation can be functionally used in patients with bilateral vestibulopathy. A more direct vestibular stimulation method can be accomplished by implantation and activation of a VI. The concept of the VI is based on the technology and principles of the CI. Different VI prototypes are currently being evaluated regarding feasibility and functionality. So far, all of them were capable of activating different types of vestibular reflexes. A third stimulation method is GVS, which requires the use of surface electrodes instead of an implanted electrode array. However, as the currents are sent through the skull from one mastoid to the other, GVS is rather unspecific. It should be mentioned though, that the reported spread of excitation in both CI and VI use also seems to induce a more unspecific stimulation. Although all three applications of EVS were shown to be effective, it has yet to be defined which option is more desirable based on applicability and efficiency. It is possible and even likely that there is a place for all three approaches, given the diversity of the patient population who serves to gain from such technologies.

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.

Evaluation of Intracochlear Position of a Slim Modiolar Electrode Array, by Using Different Radiological Analyses.

INTRODUCTION: The radiological analysis following a cochlear implantation offers insight into the audiological outcomes of cochlear implant recipients. The wrapping factor (WF) is the most common radiological analysis measuring the modiolar position and depth of insertion of an electrode array. New measurements like the intracochlear position index (ICPI) or the homogeneity factor (HF) can offer more accurate information regarding the electrode's intracochlear position. We have also studied a new method to calculate the WF, by normalizing it with a new methodology (WFn). OBJECTIVES: To analyze and compare the results of the WF, ICPI, HF, and WFn obtained using a cone beam computer tomography (CBCT) with the histological analysis on temporal bone. MATERIAL: A perimodiolar electrode array (Nucleus Slim CI532) was inserted in three temporal bones. A perfect insertion was performed in the first temporal bone, according to the correct specifications. In the second specimen, a slightly over-inserted electrode was analyzed and in the third specimen a completely over-inserted electrode array was studied. METHOD: A CBCT was performed following the implantations and then, a histological analysis with slices perpendicular to the cochlea axis (modiolus). Each measurement was made 10 times by 10 experts (radiologist and otologist) with a total amount of 600 measurements (100 for each data, 3 CBCT and 3 histology). A t test statistical analysis was performed to compare the measurements between CBCT and histology. RESULTS: It was observed that the ICPI and the HF correctly identify the three different insertions. Regarding the WF no significant difference in the two over-inserted specimens was found. The ICPI was the only measurement that shows no statistical difference between the CBCT and the histology, so it was considered the most accurate method. Finally, the WF shows a statistical difference between the CBCT and the histology in all cases, indicating the poor value of the radiological method. The WFn analysis includes the modiolar wall length in the measurement. This improves the final result as it reduces the error induced by the size of the cochlea. CONCLUSION: The ICPI and the HF provide better radiological information than the WF, regarding the intracochlear position of the electrode array. The most relevant difference is that the ICPI, HF, and WFn include modiolar and lateral wall dimensions, thereby using the diameter of the cochlear duct for the analysis.

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.

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.