Is the spread of excitation different between adults and children cochlear implants users?

PURPOSE: While cochlea is adult size at birth, etiologies and bone density may differ between children and adults. Differences in neural response thresholds (tNRT) and the spread of excitation (SOE) width may impact the use of artificial intelligence algorithms in speech processor fitting. AIM: To identify whether neural response telemetry threshold and spread of excitation width are similar in adults and children. METHODS: Retrospective cross-sectional study approved by the Ethical Board. Intraoperative tNRT and SOE recordings of consecutive cochlear implant surgeries in adults and children implanted with Cochlear devices (Cochlear™, Australia) were selected. SOE was recorded on electrode 11 (or adjacent, corresponding to the medial region of the cochlea) through the standard forward-masking technique in Custom Sound EP software, which provides SOE width in millimeters. Statistical comparison between adults and children was performed using the Mann-Whitney test (p ≤ 0.05). RESULTS: Of 1282 recordings of intraoperative evaluations, 414 measurements were selected from children and adults. Despite the tNRT being similar between adults and children, SOE width was significantly different, with lower values in children with perimodiolar arrays. Besides, it was observed that there is a difference in the electrode where the SOE function peak occurred, more frequently shifted to electrode 12 in adults implanted. In straight arrays, there was no difference in any of the parameters analyzed on electrode 11. CONCLUSION: Although eCAP thresholds are similar, SOE measurements differ between adults and children in perimodiolar electrodes.

Molecular and genetic characterization of a large Brazilian cohort presenting hearing loss.

Hearing loss is one of the most common sensory defects, affecting 5.5% of the worldwide population and significantly impacting health and social life. It is mainly attributed to genetic causes, but their relative contribution reflects the geographical region's socio-economic development. Extreme genetic heterogeneity with hundreds of deafness genes involved poses challenges for molecular diagnosis. Here we report the investigation of 542 hearing-impaired subjects from all Brazilian regions to search for genetic causes. Biallelic GJB2/GJB6 causative variants were identified in 12.9% (the lowest frequency was found in the Northern region, 7.7%), 0.4% carried GJB2 dominant variants, and 0.6% had the m.1555A > G variant (one aminoglycoside-related). In addition, other genetic screenings, employed in selected probands according to clinical presentation and presumptive inheritance patterns, identified causative variants in 2.4%. Ear malformations and auditory neuropathy were diagnosed in 10.8% and 3.5% of probands, respectively. In 3.8% of prelingual/perilingual cases, Waardenburg syndrome was clinically diagnosed, and in 71.4%, these diagnoses were confirmed with pathogenic variants revealed; seven out of them were novel, including one CNV. All these genetic screening strategies revealed causative variants in 16.2% of the cases. Based on causative variants in the molecular diagnosis and genealogy analyses, a probable genetic etiology was found in ~ 50% of the cases. The present study highlights the relevance of GJB2/GJB6 as a cause of hearing loss in all Brazilian regions and the importance of screening unselected samples for estimating frequencies. Moreover, when a comprehensive screening is not available, molecular diagnosis can be enhanced by selecting probands for specific screenings.

Is There Any Correlation between Spread of Excitation Width and the Refractory Properties of the Auditory Nerve in Cochlear Implant Users?

BACKGROUND: The spread of excitation (SOE) and auditory nerve recovery function (REC) are objective measures recorded by neural response telemetry and may interfere in cochlear implant (CI) stimulation. OBJECTIVE: To analyze and correlate SOE with the refractory periods in subjects with pre- and postlingual deafness implanted with different electrode arrays. METHODS: This was a retrospective study of 323 ears separated by perimodiolar or straight arrays and by pre- or postlingually deaf recipients. Measures were collected intraoperatively on electrode 11. The SOE width was measured in millimeters at the 0.75 point of the curve, and the relative (tau) and absolute (t0) refractory periods were measured in microseconds. RESULTS: There was a statistical correlation between the SOE and the t0 in the patients with postlingual deafness implanted with the perimodiolar array. The SOE width was statistically different between the straight and perimodiolar arrays and between the pre- and postlingual groups in the perimodiolar array. Tau was statistically different between the pre- and postlingual groups with the straight array and the t0, between the pre- and postlingual groups with the perimodiolar array. Neural response threshold and amplitude of the neural response were not statistically different among groups. CONCLUSION: There was a correlation between SOE width and t0 only in patients with acquired deafness. The findings suggest that different factors influence SOE and REC, considering SOE is different according to the electrode array and REC being different according the onset of deafness.

Is the spread of excitation width correlated to the speech recognition in cochlear implant users?

PURPOSE: To assess whether there is an interference of the spread of excitation (SOE) on speech recognition. METHODS: Retrospective cross-sectional study, approved by the institution's ethics committee (CAAE03409212.8.0000.0068). Adult patients with intraoperative neural response telemetry (NRT) performed on electrodes 6, 11 and 16 implanted with Cochlear Ltd (Sydney, Australia) devices were selected. Patients with partial array insertion, pre-lingual hearing loss, deafness etiology due to and CI experience less than 12 months were excluded. SOE was recorded at 10 current units above the NRT threshold (tNRT) and its width in millimeters was collected at point 0.75 of the function. Speech recognition test was 25-recorded monosyllables list, presented at 65 dBHL at 0° azimuth in a sound treated booth. The analysis was divided into groups by electrode array type, regarding the tNRT, SOE width, SOE's peak amplitude and electrode peak. RESULTS: A 126 SOE measurements of the 3 tested electrodes were obtained from 43 patients. Patients with straight array had significantly wider SOE, greater peak amplitude at electrode 6 and higher tNRTs. In the perimodiolar array, there was a negative correlation between SOE and monosyllables recognition at electrodes 6 and 11, and in the combined average of the three electrodes, with a significant difference in electrode 11. Sixty-six percent of the SOE measurements had their peak shifted to adjacent electrodes. CONCLUSION: It was observed, in perimodiolar array, the greater the dispersion of electrical current, the worse the speech recognition, especially in the medial electrode.

Hearing Performance in Cochlear Implant Users Who Have Facial Nerve Stimulation.

Introduction Facial nerve stimulation (FNS) is a complication in cochlear implant (CI) when the electrical current escapes from the cochlea to the nearby facial nerve. Different management to reduce its effects are available, although changes might result in a less-than-ideal fitting for the CI user, eventually reducing speech perception. Objective To verify the etiologies that cause FNS, to identify strategies in managing FNS, and to evaluate speech recognition in patients who present FNS. Methods Retrospective study approved by the Ethical Board of the Institution. From the files of a CI group, patients who were identified with FNS either during surgery or at any time postoperatively were selected. Data collection included: CI manufacturer, electrode array type, age at implantation, etiology of hearing loss, FNS identification date, number of electrodes that generated FNS, FNS management actions, and speech recognition in quiet and in noise. Results Data were collected from 7 children and 25 adults. Etiologies that cause FNS were cochlear malformation, head trauma, meningitis, and otosclerosis; the main actions included decrease in the stimulation levels followed by the deactivation of electrodes. Average speech recognition in quiet before FNS was 86% and 80% after in patients who were able to accomplish the test. However, there was great variability, ranging from 0% in quiet to 90% of speech recognition in noise. Conclusion Etiologies that cause FNS are related to cochlear morphology alterations. Facial nerve stimulation can be solved using speech processor programming parameters; however, it is not possible to predict outcomes, since results depend on other variables.

Inside-Out Transcanal Endoscopic Mastoidectomy: Literature Revision.

Introduction Recently, there have been significant advancements in transcanal endoscopic ear surgery (TEES). The combination of rigid and thin otoendoscopes with high-definition cameras enabled a less invasive transcanal access to the middle ear and a clearer view of the surgical field. Several surgeons have recently published studies about cholesteatoma resection via transcanal endoscopic surgery, even in cases where the disease has extended to the mastoid, requiring transcanal endoscopic mastoidectomy. Objectives To analyze the currently available literature on transcanal endoscopic inside-out mastoidectomy, and to determine its efficacy as a surgical technique by evaluating the disease's relapse/recurrence rate. Data Synthesis Initially, the titles and abstracts of articles identified were analyzed. At this stage, 117 articles were analyzed, 97 of which were excluded for not meeting the inclusion criteria. The 20 remaining articles were further evaluated. The articles were classified on the basis of five levels of scientific evidence. Final Comments The analysis of the studies showed that the transcanal endoscopic approach is effective in providing access to the attic or antrum, especially in cases of sclerotic mastoids. There was only one study with grade A recommendation, which showed the efficacy of endoscopic ear surgery in the treatment of cholesteatoma. Furthermore, there were three studies with grade B recommendation, showing less relapse/recurrence after TEES. More studies with grade A and B recommendations are needed to better evaluate the effectiveness of TEES, especially compared with that of traditional microscopic surgery.

Programming peculiarities in two cochlear implant users with superficial siderosis of the central nervous system.

OBJECTIVE: To report the audiological outcomes of cochlear implantation in two patients with severe to profound sensorineural hearing loss secondary to superficial siderosis of the CNS and discuss some programming peculiarities that were found in these cases. METHOD: Retrospective review. Data concerning clinical presentation, diagnosis and audiological assessment pre- and post-implantation were collected of two patients with superficial siderosis of the CNS. RESULTS: Both patients showed good hearing thresholds but variable speech perception outcomes. One patient did not achieve open-set speech recognition, but the other achieved 70% speech recognition in quiet. Electrical compound action potentials could not be elicited in either patient. Map parameters showed the need for increased charge. Electrode impedances showed high longitudinal variability. CONCLUSION: The implants were fairly beneficial in restoring hearing and improving communication abilities although many reprogramming sessions have been required. The hurdle in programming was the need of frequent adjustments due to the physiologic variations in electrical discharges and neural conduction, besides the changes in the impedances. Patients diagnosed with superficial siderosis may achieve limited results in speech perception scores due to both cochlear and retrocochlear reasons. Careful counseling about the results must be given to the patients and their families before the cochlear implantation indication.

Can the use of the CROS system provide head shadow effect contribution to unilateral Cochlear Implant Users?

PURPOSE: The aim of this study was to evaluate the contribution of the CROS system on the head shadow effect in unilateral implant users. METHODS: Prospective cross-sectional study, approved by the ethics committee under protocol 2.128.869. Eleven adults with post-lingual deafness users of unilateral Advanced Bionics CI were selected. Speech recognition was evaluated with recorded words presented at 65dBA at 0o azimuth and at 90o on the side contralateral to the CI, with noise at 55dBA, using CI alone and CI + CROS system. The results were analyzed using paired t-test with a 0.05 alpha. RESULTS: The mean speech recognition scores were significantly better with CI + CROS in relation to the condition of CI alone (p <0.05, p <0.005 and p <0.005 respectively). In the presentation at 0o azimuth, no significant differences were found. CONCLUSION: Users of unilateral CI without useful residual hearing for the use of hearing aids or unable to undergo bilateral surgery can benefit from the CROS device for speech recognition, especially when the speech is presented on the side contralateral to the CI.

Do the minimum and maximum comfortable stimulation levels influence the cortical potential latencies or the speech recognition in adult cochlear implant users?

INTRODUCTION: Cochlear implants (CI) programming is based on both the measurement of the minimum levels required to stimulate the auditory nerve and the maximum levels to generate loud, yet comfortable loudness. Seeking for guidance in the adequacy of this programming, the cortical auditory evoked potentials (CAEP) have been gaining space as an important tool in the evaluation of CI users, providing information on the central auditory system. OBJECTIVE: To evaluate the influence of mishandling of electrical stimulation levels on speech processor programming on hearing thresholds, speech recognition and cortical auditory evoked potential in adult CI users. MATERIAL AND METHODS: This is a prospective cross-sectional study, with a sample of adult unilateral CI users of both sexes, aged at least 18 years, post-lingual deafness, with minimum experience of 12 months of device use. Selected subjects should have average free field hearing thresholds with cochlear implant equal to or better than 34 dBHL and monosyllable recognition different from 0%. Individuals who could not collaborate with the procedures or who had no CAEP recordings were excluded. Participants were routinely programmed, and the map was named MO (optimized original map). Then three experimentally wrong maps were made: optimized original map with 10 current units below the maximum comfort level (C), named MC- (map minus C); optimized original map with minus 10 current units at minimum threshold level (T), named MT- (map minus T) and optimized original map with 10 current units above minimum level (T), named MT + (map plus T). In all programs, participants underwent free-field auditory thresholds from 250Hz to 6000Hz, recorded sentences and monosyllabic recognition tests presented at 65dB SPL in quiet and in noise, and free field CAEP evaluation. All tests were performed in an acoustically treated booth, in a randomized order of map presentation. Data were compared by Wilcoxon test. RESULTS: Thirty individuals were selected and signed an informed consent form. The MC- map provided worsening of all free field thresholds, quiet and noise speech recognition, and P1 wave latency delay with significant difference from the results with the MO map. The MT- map worsened the hearing thresholds and statistically significantly reduced the P2 wave latency; MT+ map improved free field thresholds except 6000Hz, worsening speech recognition, without statistical significance. CONCLUSIONS: The results suggest that maximum levels below the optimal thresholds lead to worse cochlear implant performance in both hearing thresholds and speech recognition tests in quiet and noise, increasing CAEP component P1 latency. On the other hand, the manipulation of minimum threshold levels showed alteration in audibility without significant impact on speech recognition.

Balancing the Loudness in Speech Processors and Contralateral Hearing Aids in Users of Unilateral Cochlear Implants.

Introduction The use of cochlear implants and hearing aids (bimodal) has been growing with the expansion of the indication for them, and it is important to ensure protocols so that there is a balance of the loudness regarding the two devices. Objective To evaluate if the limited complex sounds present in the frequency bands of the current devices enable the balance of the loudness in adult users of bimodal stimulation, and to analyze if speech recognition improves after balancing. Methods A prospective cross-sectional study with convenience sampling. The sample was composed of 25 adults who had used either a cochlear implant for at least 6 months or a contralateral hearing aid, with a mean age of 46 years. The balancing of the loudness was performed in an acoustic room with the computer's sound box (0° azimuth at 70 dB SPL). The instrumental sounds were filtered through eight different frequency bands. The patients used both hearing devices and were asked if the sound was perceived to be louder in one of the ears or centrally. The speech test was evaluated with sentence silence (65 dB SPL) and/or noise signal ratio of 0 dB/+ 10 dB in free field at 0° azimuth, before and after balancing. Results : Out of the 25 patients, 5 failed to achieve balance at every tested frequency, and 3 achieved balance at almost every frequency, except 8 kHz. There was a significant difference between the speech recognition test only in silence before and after balancing. Conclusion : Most patients achieved sound equalization at all evaluated frequencies under the complex-sound protocol. Additionally, most patients experienced improved speech recognition after balancing.

Neural response telemetry in patients with the double-array cochlear implant.

This study aimed to evaluate the neural response in double-array cochlear implant as well as to describe the refractory recovery and the spread of excitation functions. In a prospective study 11 patients were implanted with the double-array cochlear implant. Neural response telemetry (NRT) was performed intra-operatively. NRT threshold could be registered in 6 of the 11 patients, at least in one electrode. The remaining five patients did not show measurable neural response intra-operatively. It was noted that although recovery and spread of excitation functions could be recorded in all the tested electrodes with measurable neural responses, the responses were shown to be different from the usual register in patients with other etiologies.

Auditory and language skills in children with auditory brainstem implants.

OBJECTIVE: The aim of this study is to characterize the development of auditory and language skills in children during the first 3 years of auditory brainstem implant (ABI) use. METHOD: It is a retrospective longitudinal analysis of auditory and language skills in 12 children and pre-adolescents with pre-lingual deafness following ABI surgery (mean age at surgery: 4 years; age range: 2-11 years). Responses were analyzed aboutInfant Toddler Meaningful Auditory Integration Scale (IT-MAIS), MAIS, and Meaningful Use of Speech Scale (MUSS) at 1, 3, 6, 12, 18, 24, and 36 months after ABI activation. RESULTS: Maximum IT-MAIS/MAIS and MUSS scores after 3 years of ABI use were 45.35% and 35.28%, respectively. CONCLUSION: Pediatric patients exhibit slow progressive development of auditory and language skills following ABI activation.

Tecnologia auditiva assistiva em usuários de implante coclear em ambientes reverberantes com múltiplas fontes de ruído / Assistive listening technology in cochlear implant users in reverberant environments with multiple noise sources

RESUMO Objetivo Avaliar a contribuição da tecnologia de escuta assistida em usuários de implante coclear (IC) em situações de reverberação e ruído. Métodos Estudo transversal prospectivo aprovado pelo Comitê de Ética Institucional (CAAE 8 3031418.4.0000.0068). Foram selecionados adolescentes e adultos usuários de IC com surdez pré ou pós-lingual. Para usuários bilaterais, cada orelha foi avaliada separadamente. O reconhecimento de fala foi avaliado por meio de listas gravadas de palavras dissílabas apresentadas a 65 dBA a 0° azimute com e sem o Mini Microfone2 (Cochlear™) conectado ao processador de fala Nucleus®6. A reverberação da sala foi medida como 550 ms. Para avaliar a contribuição do dispositivo de escuta assistida (DEA) em ambiente reverberante, o reconhecimento de fala foi avaliado no silêncio. Para avaliar a contribuição do DEA em reverberação e ruído, o reconhecimento de fala foi apresentado a 0° azimute com o ruído proveniente de 8 alto-falantes dispostos simetricamente a 2 metros de distância do centro com ruído de múltiplos falantes usando relação sinal-ruído de +10dB. Para evitar viés de aprendizado ou fadiga, a ordem dos testes foi randomizada. A comparação das médias foi analisada pelo teste t para amostras pareadas, adotando-se nível de significância de p<0,005. Resultados Dezessete pacientes com idade média de 40 anos foram convidados e concordaram em participar, sendo 2 participantes bilaterais, totalizando 19 orelhas. Houve contribuição positiva significante do Mini Mic2 na reverberação e ruído+reverberação (p<0,001). Conclusão DEA foi capaz de melhorar o reconhecimento de fala de usuários de IC tanto em situações de reverberação quanto ruidosas.

ABSTRACT Purpose This study aimed to evaluate the contribution of assistive listening technology with wireless connectivity in cochlear implant (CI) users in reverberating and noise situations. Methods Prospective cross-sectional study approved by the Institutional Ethics Committee (CAAE 8 3031418.4.0000.0068). Adolescents and adults CI users with pre- or post-lingual deafness were selected. For bilateral users, each ear was assessed separately. Speech recognition was assessed using recorded lists of disyllabic words presented at 65 dBA at 0° azimuth with and without the Wireless Mini Microphone 2 (Cochlear™) connected to the Nucleus®6 speech processor. Room reverberation was measured as 550 ms. To assess the contribution of the assistive listening device (ALD) in a reverberating environment, speech recognition was assessed in quiet. To assess the contribution of the ALD in reverberation and noise, speech recognition was presented at 0° azimuth along with the noise coming from 8 loudspeakers symmetrically arranged 2 meters away from the center with multi-talker babble noise using signal to noise ratio of +10dB. To avoid learning bias or fatigue, the order of the tests was randomized. Comparison of means was analyzed by t test for paired samples, adopting significance level of p <0.005. Results Seventeen patients with a mean age of 40 years were invited and agreed to participate, with 2 bilateral participants, totaling 19 ears assessed. There was a significant positive contribution from the Mini Mic2 in reverberation, and noise+reverberation (p <0.001). Conclusion ALD was able to improve speech recognition of CI users in both reverberation and noisy situations.

Hearing Performance in Cochlear Implant Users Who Have Facial Nerve Stimulation

Abstract Introduction Facial nerve stimulation (FNS) is a complication in cochlear implant (CI) when the electrical current escapes from the cochlea to the nearby facial nerve. Different management to reduce its effects are available, although changes might result in a less-than-ideal fitting for the CI user, eventually reducing speech perception. Objective To verify the etiologies that cause FNS, to identify strategies in managing FNS, and to evaluate speech recognition in patients who present FNS. Methods Retrospective study approved by the Ethical Board of the Institution. From the files of a CI group, patients who were identified with FNS either during surgery or at any time postoperatively were selected. Data collection included: CI manufacturer, electrode array type, age at implantation, etiology of hearing loss, FNS identification date, number of electrodes that generated FNS, FNS management actions, and speech recognition in quiet and in noise. Results Data were collected from 7 children and 25 adults. Etiologies that cause FNS were cochlear malformation, head trauma, meningitis, and otosclerosis; the main actions included decrease in the stimulation levels followed by the deactivation of electrodes. Average speech recognition in quiet before FNS was 86% and 80% after in patients who were able to accomplish the test. However, there was great variability, ranging from 0% in quiet to 90% of speech recognition in noise. Conclusion Etiologies that cause FNS are related to cochlear morphology alterations. Facial nerve stimulation can be solved using speech processor programming parameters; however, it is not possible to predict outcomes, since results depend on other variables.

Caloric test and video head impulse test sensitivity as vestibular impairment predictors before cochlear implant surgery.

OBJECTIVES: Currently, cochlear implant procedures are becoming increasingly broad and have greatly expanded. Bilateral cochlear implants and cochlear implants are more frequently applied in children. Our hypothesis is that the video head impulse test may be more sensitive than the caloric test in detecting abnormal vestibular function before cochlear implant surgery. The objective of this study was to compare the video head impulse test and caloric test results of patients selected for cochlear implant procedures before surgery. METHODS: The patients selected for cochlear implant surgery were submitted to a bithermal caloric test and video head impulse test. RESULTS: By comparing angular slow phase velocity values below 5° in the bithermal caloric test (hypofunction) and video head impulse test with a gain lower than 0.8, we identified 37 (64.9%) patients with vestibular hypofunction or canal paresis and 21 (36.8%) patients with abnormal video head impulse test gain before the cochlear implant procedure. Of the 37 patients with caloric test vestibular hypofunction, 20 (54%) patients exhibited an abnormal gain in the video head impulse test. CONCLUSION: The caloric test is more sensitive than the video head impulse test (Fisher's exact test, p=0.0002) in detecting the impaired ear before cochlear implant delivery. The proportion of caloric test/video head impulse test positive identification of abnormal vestibular function or caloric test/video head impulse test sensitivity was 1.8:1.

The Influence of Auditory Feedback and Vocal Rehabilitation on Prelingual Hearing-Impaired Individuals Post Cochlear Implant.

OBJECTIVE: To verify changes in the perceptual and acoustic vocal parameters in prelingual hearing-impaired adults with cochlear implants after vocal rehabilitation. HYPOTHESIS: Auditory feedback restoration alone after cochlear implant is not enough for vocal adjustments. A targeted and specific voice therapy intervention is required. STUDY DESIGN: Prospective and pre-post repeated measures design. METHODS: Twenty literate adults with severe to profound prelingual bilateral sensorineural hearing loss participated in the study; individuals were implanted late and were fluent users of oral language. Ages ranged from 17 to 48 years. All individuals presented normal results in laryngoscopy, and hearing thresholds with the cochlear implant were over 40 dB HL. Individuals were randomly distributed into two groups: Group 1 (treatment group) and Group 2 (control group), both with ten patients each, five men and five women, matching mean age and hearing deprivation time before the cochlear implantation. Patients from Group 1 underwent a protocol of vocal therapy including 12 individual sessions with the same clinician. Group 2 only underwent vocal recordings. The vocal recordings occurred before and after the participation in the therapy protocol for Group 1 and after the same period, 3 months later, without any intervention, for Group 2. The recording sessions used the Consensus Auditory-Perceptual Evaluation of Voice protocol sentence reading and emission of sustained vowel /a/. Auditory-perceptual evaluation of voices was performed by three judges, and the acoustical analysis used the Praat program. RESULTS: Statistically significant reductions in the overall vocal degree, vocal instability, and degree of resonance change were observed after vocal rehabilitation in Group 1. Statistically, individuals from Group 1 did not differ in regard to the modification of acoustic parameters. Group 2 did not present significant changes in any of the analyzed parameters. CONCLUSIONS: The cochlear implanted adults submitted to vocal rehabilitation presented changes in the auditory-perceptual parameters, with reduction of the overall voice severity, vocal instability, and degree of resonance after vocal intervention. There were no changes in the acoustic parameters in the implanted prelingual hearing-impaired adult subjects.

Video head impulse test relevance in the early postoperative period after cochlear implantation.

BACKGROUND: Cochlear implantation (CI) is the gold standard therapy for profound or severe sensorineural hearing loss. It is a safe surgical procedure but, because of the proximity of the cochlea and vestibule, postoperative vestibular disorder may occur. Our hypothesis is that the video head impulse test (vHIT) may be a good tool to achieve a topographic diagnosis of dizziness in the early postoperative period after CI. AIMS/OBJECTIVES: To evaluate patients with instability, imbalance and vertigo between 7 and 14 days after CI procedure. MATERIAL AND METHODS: A total of 31patients scheduled for unilateral CI were included in this study. vHIT for horizontal semicircular canal was performed before CI and between days 7 to 14 after the surgery. RESULTS: Six subjects had dizziness complaints after CI: instability (N = 2), imbalance (N = 2) and vertigo (N = 2). The postoperative vHIT test turned abnormal only in subjects with vertigo as compared to the preoperative vHIT test results. CONCLUSION AND SIGNIFICANCE: vHIT is a good vestibular function test during the first 2 weeks after CI surgery when vertigo is the main complaint.

Cochlear anatomy study used to design surgical instruments for cochlear implants with two bundles of electrodes in ossified cochleas.

UNLABELLED: Cochlear ossification, mainly secondary to meningitis, prevents the complete conventional cochlear implant insertion. Implants with two electrode bundles shorter than the conventional ones were specifically developed for ossified cochleas. However, during surgery there is a high risk of damaging the internal carotid artery (ICA). Therefore, measuring cochleostomy depth in order to insert the two electrode bundles would greatly increase the procedure's safety. AIMS: 1) Find the distances between cochleostomies and ICA in cadaver temporal bones. 2) Design an instrument that can be used in cochlear implant surgery to introduce an implant with two bundles of electrodes. STUDY DESIGN: Experimental prospective. MATERIALS AND METHODS: In 21 temporal bones from cadavers we performed: 1) canal wall down mastoidectomy; 2) cochleostomy in the cochlear basal and middle turns; 3) ICA identification; 4) Length determination between the cochleostomies and the artery. RESULTS: the average distance +/- standard deviation obtained for the upper tunnel was of 8.2 +/- 1.1 mm and for the lower tunnel it was of 8.1+/- 1.3 mm. The shortest distance found was of 6.5 mm for the upper tunnel and 6.0 mm for the lower tunnel. CONCLUSION: Despite the values calculated, we concluded that the best value to be considered in creating a surgical instrument are the minimum lengths obtained for each one of the cochlear turns, because this is the safest way to avoid damaging the ICA, that can be fatal.

Auditory Brainstem Implant: surgical technique and early audiological results in patients with neurofibromatosis type 2.

UNLABELLED: Auditory Brainstem Implants were developed to partially restore the hearing capabilities of patients without cochlear nerves bilaterally. AIM: this paper aims to discuss the clinical and surgical findings of four ABI patients. MATERIALS AND METHOD: Four patients diagnosed with bilateral schwannomas received auditory brainstem implants (ABI) and had one of their tumors resected in the same surgical procedure. Clinical aspects, surgical technique, anatomic landmarks, and outcomes were analyzed. RESULTS: the anatomic landmarks were identified in all four patients in relation to the foramina of Luschka. Two patients had CSF leaks. The electrodes were well positioned and hearing sensation was good enough to allow for sound recognition and assist patients perform lip reading. CONCLUSION: the outcomes observed in our patients were quite encouraging and offer great perspectives for those suffering from deep bilateral deafness and impaired central auditory pathways.

Inside-Out Transcanal Endoscopic Mastoidectomy: Literature Revision

Abstract Introduction Recently, there have been significant advancements in transcanal endoscopic ear surgery (TEES). The combination of rigid and thin otoendoscopes with highdefinition cameras enabled a less invasive transcanal access to the middle ear and a clearer view of the surgical field. Several surgeons have recently published studies about cholesteatoma resection via transcanal endoscopic surgery, even in cases where the disease has extended to the mastoid, requiring transcanal endoscopic mastoidectomy. Objectives To analyze the currently available literature on transcanal endoscopic inside-out mastoidectomy, and to determine its efficacy as a surgical technique by evaluating the disease's relapse/recurrence rate. Data Synthesis Initially, the titles and abstracts of articles identified were analyzed. At this stage, 117 articles were analyzed, 97 of which were excluded for not meeting the inclusion criteria. The 20 remaining articles were further evaluated. The articles were classified on the basis of five levels of scientific evidence. Final Comments The analysis of the studies showed that the transcanal endoscopic approach is effective in providing access to the attic or antrum, especially in cases of sclerotic mastoids. There was only one study with grade A recommendation, which showed the efficacy of endoscopic ear surgery in the treatment of cholesteatoma. Furthermore, there were three studies with grade B recommendation, showing less relapse/recurrence after TEES. More studies with grade A and B recommendations are needed to better evaluate the effectiveness of TEES, especially compared with that of traditional microscopic surgery.