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, 2023.

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.

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.

Ultrasound-guided pediatric vascular cannulation by inexperienced operators: outcomes in a training model.

OBJECTIVE: To present the results of an ultrasound vascular cannulation (UGVC) training program for inexperienced operators using a training model. METHOD: This was a descriptive observational study developed in the paediatric intensive care unit (PICU) of a third-level hospital. Operators received basic theoretical training in the USVC technique, followed by practical training with a model designed for USVC-inexperienced healthcare professionals. RESULTS: The study included 25 healthcare professionals, who carried out a total of 300 ultrasound-guided cannulation procedures (12 per participant) at equidistant sites on the longitudinal axis/in-plane (LA/IP) and the transverse axis/out-of-plane (TA/OP). The mean depth of cannulated vessels was 0.90 (0.34) cm and their mean diameter was 0.41 (0.1) cm. In 41.7% of cases, complete view of the needle (CVN) was accomplished; in 49% of cases, repositioning of the needle/guidewire (RNG) was necessary for successful UGVC. The rate of successful UGVC in the training model was 79.7%. The mean time required for the procedure was 74.70 (73.72) seconds. The time to successful cannulation was 58.72 (56.87) seconds. The mean number of attempts needed until successful UGVC was 1.31 (0.72). Complications were: (a) 26.3% vessel perforation/wrong guidewire positioning (VP/WGP) and (b) 4.3% successful vessel puncture followed by failure to accomplish subsequent cannulation. CONCLUSIONS: Through the present theoretical-practical training program for inexperienced operators using a training model: (a) high success rates and short procedural times were attained; (b) complete view of needle and need for repositioning the needle/guidewire occurred in half of the procedures; and (c) complications occurred in a third of the procedures.

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.

Analysis of Neural Interface When Using Modiolar Electrode Stimulation. Radiological Evaluation, Trans-Impedance Matrix Analysis and Effect on Listening Effort in Cochlear Implantation.

BACKGROUND: The proximity of the electrode to the modiolar wall may be of interest to investigate the effect of pitch discrimination. This research establishes the relation between these factors and whether perimodiolar positions may provide benefits regarding improved electrode discrimination. METHODS: A prospective randomized study including 24 post-lingual deaf adults was performed. A psychoacoustic study was done by using a psychoacoustic research platform. Radiological study, and a cone-beam computed tomography was used to assess post cochlear implantation electrodes' position. Trans-impedance matrix (TIM) analysis was performed after cochlear implant insertion in all cases, and pupillometry test was also performed. RESULTS: 12 patients received a slim perimodiolar electrode array, and 12 patients received a straight electrode array. Although all the patients showed similar speech test results after 12 months follow-up, those implanted with a perimodiolar electrode obtained better scores in electrode discrimination test and pupillometry test, and showed more homogenous TIM patterns. CONCLUSIONS: The better positioning of the electrode array seams to provide a better hearing resolution and less listening effort trans-impedance matrix seems to be a useful tool to analyze positioning of the perimodiolar array.

[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.

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.

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.

Epidemiología de los trastornos vestibulares en la consulta de otoneurología / Epidemiology of vestibular disorders in the otoneurology unit

Introducción y objetivos: El conjunto de síntomas relacionados con los trastornos del sistema de equilibrio son comunes en la población general. Sin embargo, hay pocos estudios que cuantifiquen la frecuencia de inicio de los diversos trastornos vestibulares que se presentan en unidades especializadas de otoneurología. El objetivo de este estudio es establecer la epidemiología de los trastornos vestibulares, La forma de presentación y la carga de atención esperada en una clínica especialista en otoneurología. Material y métodos: Estudio descriptivo observacional retrospectivo sobre los pacientes remitidos a la consulta de Otoneurología de un centro hospitalario de tercer nivel entre el 1/1/2015 y el 31/12/2015. Resultados: Fueron valorados 174 pacientes (121 mujeres y 53 hombres) con una media de edad de 5 3± 17 años. Durante el periodo de estudio se valoraron 43 individuos por cada 100.000 habitantes. Los pacientes fueron remitidos en su mayoría desde consultas externas de Otorrinolaringología (36,8%) y desde Atención Primaria (28,7%). El motivo de consulta más frecuente fue inestabilidad (40,2%), seguido de vértigo (31%). Los diagnósticos más frecuentes fueron vértigo posicional paroxístico benigno (28,2%) y migraña vestibular (28,2%) -definida (59%) o probable (41%)-, seguidos de enfermedad de Ménière (13.8%), trastornos de origen vascular (5.7%), mareo subjetivo crónico (4,6%) y neuritis vestibular (4%). Conclusiones: Disponer de información precisa acerca de la prevalencia e impacto de los trastornos vestibulares es importante para la correcta planificación de los servicios sanitarios con el objetivo de responder satisfactoriamente a la demanda asistencial esperada en la comunidad. El trastorno más frecuentemente diagnosticado en una consulta de Otoneurología es el vértigo posicional paroxístico benigno y la migraña vestibular. Para la comparación de resultados es indispensable la utilización de terminología sistemática (AU)

Introduction and objectives: The set of symptoms relating to disorders of the balance system are common in the general population. However, there are few studies quantifying the frequency of onset of the various vestibular disorders that present in specialist otoneurology units in the Spanish population. The aim of this study is to establish the epidemiology of vestibular disorders, their form of presentation, and the expected care burden in a specialist otoneurology clinic. Material and methods: A retrospective, descriptive, observational study of patients referred to the otoneurology unit of a third level hospital between 1/1/2015 and 31/12/2015. Results: One hundred and seventy-four patients were assessed (121 women and 53 men) with a mean age of 53 ± 17 years. Forty-three individuals per 100,000 inhabitants were assessed over the study period. The patients were referred in the majority from external ENT (36.8%) and primary care (28.7%) clinics. The most frequent reason for consultation was dizziness (40.2%) followed by vertigo (31%). The most frequent diagnoses were benign paroxysmal positional vertigo (28.2%) and vestibular migraine (28.2%) -defined (59%) or probable (41%)-, followed by Ménière's disease (13.8%), vascular disorders (5.7%), chronic subjective dizziness (4.6%) and vestibular neuritis (4%). Conclusions: The availability of precise information on the prevalence and impact of vestibular disorders is important to enable the health services to plan an appropriate response to the expected care demand in the community. Benign paroxysmal positional vertigo and vestibular migraine are the most commonly diagnosed disorders in otoneurology clinics. Systematic terminology is essential for the comparison of results (AU)

Mechanisms of electrode fold-over in cochlear implant surgery when using a flexible and slim perimodiolar electrode array.

OBJECTIVES: This study evaluates the design of a thin perimodiolar cochlear implant electrode array (CI532) and assesses insertion-related rotation and fold-over. METHODS: The study consisted on a cochlear model and temporal bone insertion studies. Twenty insertions were studied, under four different surgical insertion conditions in vitro, the intracochlear disposition of the electrode array and presence of tip fold over were recorded. Also, eight fresh human temporal bones were studied after insertion in two conditions: correct alignment of the electrode array during the insertion and misaligned. These surgical situations were investigated within this study using a video recording of the dynamics of insertion techniques and X-ray, including fluoroscopy, Cone Beam CT, and digital imaging analysis. RESULTS: For electrodes inserted with a correct surgical technique, the placement was perfect, within the scala tympani. The wrapping factor was 0.53, and the perimodiolar distance was below 0.3 mm, with a mean insertion depth of 405°. CONCLUSIONS: A perimodiolar position can be achieved with the new CI532 electrode array. The new electrode also seems to be reliable for atraumatic intracochlear placement in scala tympani (ST).

Vestibular Response to Electrical Stimulation of the Otolith Organs. Implications in the Development of A Vestibular Implant for the Improvement of the Sensation of Gravitoinertial Accelerations.

OBJECTIVE: Electrical stimulation of the utricular and saccular portions of the vestibular nerve improves stability in patients suffering from vestibular dysfunction. The main objective of this study was to evaluate a new technique, vestibular response telemetry (VRT), for measuring the electrically evoked vestibular compound action potential (saccular and utricular) after stimulating the otolith organ (saccular and utricular) in adults. This study used evidence that the otolith organ can be electrically stimulated in order to develop a new vestibular implant design to improve the sensation of gravitoinertial acceleration. MATERIALS AND METHODS: Four adult patients were evaluated by using a variety of measurement procedures with novel VRT software. VRT values were obtained by stimulating with three full-band Nucleus CI24RE (ST) electrodes. Specific stimuli were used. Simultaneously, electrical ocular vestibular evoked myogenic potentials (eoVEMPs) were recorded in the contralateral side. RESULTS: Electrically evoked compound action potentials were obtained in 10 of the 12 electrodes tested, and eoVEMPs were recorded when VRT was present. In addition to the validation of this technique, a set of default clinical test parameters was established. The VRT response morphology consisted of a biphasic waveform with an initial negative peak (N1) followed by a positive peak (P1), and latencies were typically 400 µs for N1 and 800 µs for P1. The consequences for the development of a vestibular implant for the improvement of gravitoinertial acceleration sensation are also presented. CONCLUSION: The VRT measurement technique has been shown to be a useful tool to record neural response on the otolith organ, and thus it is a convenient tool to evaluate whether the implanted electrodes provide a neural response or not. This can be used for the early development of vestibular implants to improve gravitoinertial acceleration sensation.