Computed tomography multi-planar and 3D image assessment protocol for detailed analysis of inner ear malformations in patients undergoing cochlear implantation counseling

<b><br>Introduction:</b> Congenital inner ear malformations resulting from embryogenesis may be visualized in radiological scans. Many attempts have been made to describe and classify the defects of the inner ear based on anatomical and radiological findings.</br> <b><br>Aim:</b> The aim was to propose and discuss computed tomography multi-planar and 3D image assessment protocols for detailed analysis of inner ear malformations in patients undergoing cochlear implantation counseling.</br> <b><br>Material and methods:</b> A retrospective analysis of 22 malformed inner ears. CT scans were analyzed using the Multi-Planar Reconstruction (MPR) option and 3D reconstruction.</br> <b><br>Results:</b> The protocol of image interpretation was developed to allow reproducibility for evaluating each set of images. The following malformations were identified: common cavity, cochlear hypoplasia type II, III, and IV, incomplete partition type II and III, and various combinations of vestibule labyrinth malformations. All anomalies have been presented and highlighted in figures with appropriate descriptions for easier identification. Figures of normal inner ears were also included for comparison. 3D reconstructions for each malformation were presented, adding clinical value to the detailed analysis.</br> <b><br>Conclusions:</b> Properly analyzing CT scans in cochlear implantation counseling is a necessary and beneficial tool for appropriate candidate selection and preparation for surgery. As proposed in this study, the unified scans evaluation scheme simplifies the identification of malformations and reduces the risk of omitting particular anomalies. Multi-planar assessment of scans provides most of the necessary details. The 3D reconstruction technique is valuable in addition to diagnostics influencing the decision-making process. It can minimize the risk of misdiagnosis. Disclosure of the inner ear defect and its precise imaging provides detailed anatomical knowledge of each ear, enabling the selection of the appropriate cochlear implant electrode and the optimal surgical technique.</br>.

Long-term outcomes and electrophysiological measures of children with inner ear malformations and cochlear implants

OBJECTIVES

To compared auditory and speech performance outcomes of children with cochlear implants (CI), between those with inner ear malformations (IEMs) and with normal ear anatomy; and to describe differences in electrophysiological measurements.

STUDY DESIGN

A retrospective study.

SETTING

A tertiary care pediatric medical center.

PATIENTS

Forty-one children with IEMs who underwent CI during 2003-2017, and 41 age-matched CI recipients with normal ear anatomy (control group).

MAIN OUTCOME MEASURES

Post-CI auditory performance outcomes including educational setting, Categories of Auditory Performance (CAP), and Speech Intelligibility Rating (SIR); and electrophysiological measurements, Including maximal comfortable electrical levels (CLs) and impedances along CI electrodes.

RESULTS

The ANOVA on ranks revealed lower CAP scores in the study than control group: H3 = 18.8, P < 0.001. Among children with IEMs, CAP scores were better in children with enlarged vestibular aqueduct (EVA) (P < 0.04). SIR scores of the control group did not differ from those with isolated EVA; however, SIR scores of the IEMs without EVA subgroup were lower than all the other study subgroups (P < 0.01). The proportion of the control group that was integrated with full inclusion educational settings into the regular mainstream schools was higher than for those with IEMs without EVA (47 % vs. 15 %, P < 0.05), but similar to those with isolated EVA. For the study group versus control group, maximal comfortable electrical levels (CLs) were higher)P > 0.03) while impedance measurements were similar.

CONCLUSIONS

Outcomes of pediatric recipients with normal anatomy were better than those with IEMs. Among pediatric recipients of CI with IEMs, auditory performance was better and CLs were lower among children with isolated EVA than all other IEM subgroups.

A Long-Term Follow-Up Study on the Auditory Performance and Speech Intelligibility of Mandarin-Speaking Prelingually Deaf Children With Isolated Large Vestibular Aqueduct Syndrome After Cochlear Implantation

PURPOSE

The purpose of this study was to evaluate the auditory performance and speech perception of 104 children with isolated large vestibular aqueduct syndrome (LVAS) and 523 children with no inner ear malformation (IEM) for 5 years after cochlear implantation, in order to explore whether isolated LVAS can affect the long-term hearing and speech rehabilitation of deaf children after cochlear implantation.

METHOD

A cohort study was established consisting of 627 children who underwent cochlear implantation at Beijing Tongren Hospital from 1999 to 2016. The children were examined at 0, 6, 12, 24, 36, 48, and 60 months after cochlear implantation to assess their auditory performance and speech perception using the Categories of Auditory Performance (CAP) and Speech Intelligibility Rating (SIR) questionnaires.

RESULTS

The CAP scores of the isolated LVAS group increased significantly during the baseline to the 24th month, after which they gradually rose until reaching the plateau during the 24th to the 60th month. The CAP scores of the non-IEM group increased significantly during the baseline to the 36th month and then increased steadily. The SIR scores went up significantly during the baseline to the 48th month, and increased in a gradual manner in other stages of isolated LVAS evaluation. In comparison, The SIR scores of non-IEM group grew remarkably from the baseline to the 60th month. There were no significant differences in the CAP or SIR scores between isolated LVAS and non-IEM groups in each stage of evaluation, with the only exception being the CAP score at baseline month after cochlear implantation.

CONCLUSIONS

The CAP and SIR questionnaires are helpful tools for quantifying the early hearing and speech skills of younger prelingually deafened cochlear implant recipients. This long-term follow-up study shows that the speech and hearing development of children in isolated LVAS and non-IEM groups follow similar patterns, and isolated LVAS does not affect the long-term rehabilitation of deaf children after cochlear implantation.

Subtotal Petrosectomy: Pictorial Review of Clinical Indications and Surgical Approach

Subtotal petrosectomy (STP) is characterized by obliteration of the middle ear and occlusion of the external auditory canal. The advent of the endoscope has allowed a reduction in morbidity for some conditions such as cholesteatoma and other middle ear disorders, but STP still plays an important role. A retrospective review of medical records and videos of patients who had undergone STP was performed. Perioperative data and images were collected from various clinical cases who had undergone subtotal petrosectomy at our tertiary referral university hospital in Verona. We confronted our experience with a review of the literature to present the main indications for this type of procedure. STP allows a variety of diseases to be managed effectively as it offers the possibility of a definitive healing with radical clearance of temporal bone. Moreover, it can be safely combined with other procedures with a very low complication rate. Although the endoscope represents a revolution in ear surgery, STP, when indicated, is nowadays a surgical option that should be included in the otosurgeon's portfolio.

Cochlear Implant Insertion Routes and Intra-operative Electrophysiological Measurements: A Retrospective Analysis at a Tertiary Care Centre

BACKGROUND

Cochlear implant surgeries are performed by different surgical routes, Round window (RW), Extended round window (Ext RW) and Cochleostomy (C). Optimum intracochlear electrode placement is important to achieve a successful outcome. Intra-operative electrophysiological testing (Impedance and ECAP) is crucial to assess the device function and appropriate electrode placement. The variability of portal of electrode insertion might affect the neural response and its characteristics.

OBJECTIVE

To compare the intraoperative electrophysiological measurements (Impedance and ECAP) for possible differences on auditory nerve stimulation across the three electrode insertion routes.

MATERIALS AND METHODS

This is a retrospective data analysis of 47 cochlear implant recipients at a tertiary care centre in Central India over a period of 4 years. They were broadly divided into two groups depending on the electrode design as full banded and half banded. Intraoperative impedances were recorded for different modes of stimulation and ECAP measured at E5, E10, E15, E20 electrodes in both the groups across the three insertion routes.

RESULTS

In the half-banded group, the impedance values in different modes CG, MP1, MP2, MP1 + 2 did not differ significantly among the surgical routes at all four electrodes. While in the full banded group, for CG mode impedance values at E5 differ significantly. Rest for other modes in full banded group, there was no statistically significant difference across the three routes.

CONCLUSION

The present study supports that there is no statistically significant difference in the intraoperative impedance and ECAP measurements in both, the full-banded and half- banded electrodes across the three surgical routes implying that, all the three surgical approaches provide equal stimulation of the auditory nerve. The CI surgeon can select the electrode insertion portal based on the surgical anatomy, the implant type and individual preferences.

Effect of congenital inner ear malformations (IEMs) on electrically evoked compound action potential (ECAP) responses in cochlear implant children

PURPOSE

The study was designed to assess the electrically evoked compound action potential (ECAP) responses in children with inner ear malformations compared to children with normal inner ear anatomy.

METHODS

The study included 235 prelingual deaf children who were implanted in cochlear implant unit in King Fahad University hospital-Imam Abdulrahman Bin Faisel University. Subjects were using either Cochlear Nucleus or Medel cochlear implant devices. We had 171 (64.5%) subjects with normal inner ear anatomy and 94 (35.5%) subjects with inner ear malformations (IEMs) and they were classified into 6 groups according to inner ear anatomy. Fourteen subjects (14.9%) subjects had enlarged vestibular aqueduct (EVA), 30 (32%) subjects had Mondini deformity, 25 (26.6%) subjects had incomplete partition type two (IPII), 9 (9.6%) subjects had incomplete partition type one (IPI) and 16 (17%) subjects had hypoplastic cochlea type III or IV. Intraoperative electrically evoked compound action potential (ECAP) responses were analyzed and compared in all subjects.

RESULTS AND CONCLUSIONS

Measurable ECAP responses can be elicited in patients with IEMs in most of the channels. Severe malformations can affect the prevalence of measuring ECAP and getting identifiable waveform morphology. Additionally, increased thresholds and lower slope of AGF was observed in IEMs specially in more severe malformations (e.g. IPI). IPI patients with better word recognition scores tended to show more identifiable ECAP measurements. This could suggest the presence of some correlation between ECAP responses and patients' performance after cochlear implantation.

Cochlear implantation programming characteristics and outcomes of cochlear nerve deficiency

PURPOSE

Due to the specificity of cochlear implantation (CI) programming parameters and outcomes in cochlear nerve deficiency (CND) patients, this study aimed to investigate the correlation between programming parameters and outcomes and further compare the difference between normal and CND groups.

METHODS

Ninety (95 ears) CND patients (normal cochlea, 39; malformed cochlea, 56) and seventy-nine (81 ears) normal cochlea patients who underwent CI surgery with either Med-El or Cochlear devices were included. The programming parameters and outcomes evaluated by the questionnaires were collected and compared among the normal CND, malformed CND, and normal groups in the two device groups, and their correlation was analyzed.

RESULTS

In the CND group, a reduced stimulation rate, higher pulse width, and triphasic pulse were needed in some cases. The stimulus levels of the CND group were significantly higher than that of the normal group (p < 0.05), but the outcomes of the CND group were significantly worse than that of the normal group (p < 0.05), and the stimulus level was significantly correlated with the outcomes (p < 0.05). However, there was no difference between normal and malformed CND groups. The non-auditory response was observed in the CND group, especially the ones with malformations.

CONCLUSION

The CI programming parameters of some CND patients need to be adjusted, and a slower stimulation rate and higher pulse width are required sometimes. CND patients need a higher stimulus level than normal patients but their outcomes are poorer. Non-auditory response should be noticed in CND patients during programming.

Incomplete Partition Type II Cochlear Malformations: Delineating the Three-Dimensional Structure from Digitized Human Histopathological Specimens

HYPOTHESIS

There are clinically relevant differences in scalae anatomy and spiral ganglion neuron (SGN) quantity between incomplete partition type II (IP-II) and normal cochleae.

BACKGROUND

IP-II is a commonly implanted cochlear malformation. Detailed knowledge of intracochlear three-dimensional (3D) morphology may assist with cochlear implant (CI) electrode selection/design and enable optimization of audiologic programming based on SGN maps.

METHODS

IP-II (n = 11) human temporal bone histological specimens were identified from the National Institute on Deafness and Other Communication Disorders National Temporal Bone Registry and digitized. The cochlear duct, scalae, and surgically relevant anatomy were reconstructed in 3D. A machine learning algorithm was applied to map the location and number of SGNs.

RESULTS

3D scalae morphology of the basal turn was normal. Scala tympani (ST) remained isolated for 540 degrees before fusing with scala vestibuli. Mean ST volume reduced below 1 mm 2 after the first 340 degrees. Scala media was a distinct endolymphatic compartment throughout; mean ± standard deviation cochlear duct length was 28 ± 3 mm. SGNs were reduced compared with age-matched norms (mean, 48%; range, 5-90%). In some cases, SGNs failed to ascend Rosenthal's canal, remaining in an abnormal basalward modiolar location. Two forms of IP-II were seen: type A and type B. A majority (98-100%) of SGNs were located in the basal modiolus in type B IP-II, compared with 76 to 85% in type A.

CONCLUSION

Hallmark features of IP-II cochleae include the following: 1) fusion of the ST and scala vestibuli at a mean of 540 degrees, 2) highly variable and overall reduced SGN quantity compared with normative controls, and 3) abnormal SGN distribution with cell bodies failing to ascend Rosenthal's canal.

Cochlear Implantation Outcomes in Pediatrics with Inner Ear Malformations in a Tertiary Care Hospital in Ahvaz

Cochlear implantation (CI) has been successful in individuals with sensorineural hearing loss (SNHL) over the last few years. This study assessed the auditory and speech performance results of pediatrics with inner ear malformations (IEMs) following cochlear implantation at the Ahvaz cochlear implantation center and compared the outcomes of various malformations. All pediatrics with IEMs undergoing CI were included in the study. This retrospective study was performed on pediatrics with congenital IEMs who underwent cochlear implantation in Ahvaz cochlear implantation center between 2014 and 2019. The Category of Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) scores are two of the most frequently administered tests. The CAP with ranging from 0 (displays no awareness of environmental sounds) to 7 (can use the telephone with a familiar talker), was used to measure the speech perception performance of the implanted children. Furthermore, SIR consists of five performance categories ranging from "prerecognizable words in spoken language" to "connected speech is intelligible to all listeners". Finally, the study included 22 patients. The evaluation of the CT-Scan revealed three types of inner ear malformation: Incomplete Partition (IP)-I in 2 (9.1%), IP-II in 12 (54.5%), and common cavity in 8 (36.4%) individuals. The results were shown that the median CAP score preoperative was 0.5 (interquartile range (IQR): 0-2) and postoperative was 3.5 (IQR: 3-7). There were statistically significant differences in CAP scores between preoperative and second-year follow-up postoperative (p value = 0.036). The results were shown that the median SIR score preoperative was 1 (IQR: 1-5) and postoperative was 2 (IQR: 1-5). There were statistically significant differences in SIR scores between preoperative and second-year follow-up postoperative (p value = 0.001). Following a thorough preoperative screening, patients with specific IEMs can be candidates for CI and not a contraindication. There were statistically significant differences in CAP and SIR scores between preoperative and second-year follow-up postoperative in the common cavity and IP-II groups.

Cochlear implantation in children with congenital inner ear malformations - Our experience

OBJECTIVE

To share our experience of the surgical challenges faced in cochlear implanted patients with inner ear malformation and to assess the auditory and speech perception outcomes.

MATERIAL AND METHOD

Clinical records of 502 cochlear implant procedures were reviewed and data of 122 patients who had inner ear malformations were enrolled in the study. Their auditory and speech performances were evaluated post implantation for 3 years.

RESULT

Cerebrospinal fluid gusher was encountered during opening of cochlea in 42 patients (34.4%) and one patient was re-explored within 24 h. In 30.3% of cases facial anomaly was found. Significant improvement in average performance was seen in all malformation types except in cochlear hypoplasia at 12 months postoperatively.

CONCLUSION

Surgical challenges can be overcome with expertise and giving special attention to preoperative imaging. Our experience suggests that outcomes are favourable in patients with inner ear malformations too.

Cochlear implantation in a patient with congenital microtia, cochlear hypoplasia, venous anomalies of the temporal bone and laryngomalacia: Challenges and surgical considerations

RATIONALE AND PATIENT CONCERNS

Congenital hearing loss is often caused by an inner ear malformation, in such cases, the presence of other anomalies, such as microtia, and venous anomalies of the temporal bone and laryngomalacia makes it challenging to perform cochlear implantation surgery.

DIAGNOSES

This study reports the case of a 28-month-old girl with congenital profound hearing loss, laryngomalacia, and malformed inner ear, who received cochlear implantation surgery. The bony structure, vessels and nerves were first assessed through magnetic resonance imaging and computed tomography before exploring the genetic basis of the condition using trio-based whole exome sequencing. Perioperative evaluation and management of the airway was then performed by experienced anesthesiologist, with the surgical challenges as well as problems encountered fully evaluated.

INTERVENTIONS

Cochlear implantation was eventually performed using a trans-mastoid approach under uneventful general anesthesia.

OUTCOMES

Due to the small size of the cochlea, a short electrode FLEX24 was inserted through the cochleostomy.

LESSONS

Considering the high risk of facial nerve injury and limited access to the cochlea when patients present significant bony and venous anomalies, cochlear implantation in such patients require careful preoperative evaluation and thoughtful planning. In these cases, airway assessment, magnetic resonance venography, magnetic resonance arteriography, and magnetic resonance imaging and computed tomography can be useful to minimize the risks. Intraoperative facial nerve monitoring is also recommended to assist in the safe location of facial nerve.

Speech Perception and Sound Localization Skills in Inner Ear Malformations: Children With Incomplete Partition Type-II

OBJECTIVE

The present study aimed to evaluate binaural auditory skills in bimodal and bilateral pediatric cochlear implant (CI) users with incomplete partition type-II (IP-II) and to reveal the effect of IP-II on performance by comparing the results to pediatric CI users with normal cochlear morphology.

STUDY DESIGN

Cross-sectional study.

SETTING

Tertiary referral center.

METHODS

Forty-one CI users (mean age 8.8 ± 1.9) were grouped as bimodal (BIM-IP) and bilateral (BIL-IP) users with IP-II; bimodal (BIM-N) and bilateral (BIL-N) users with normal cochlear anatomy. Speech perception in noise and sound localization skills were compared under 2 conditions; binaural (bilateral or bimodal) and monaural (first CI alone).

RESULTS

BIM-IP and BIL-IP showed no performance difference in binaural tasks. The BIM-N group showed remarkably poor performance in comparison to the groups of BIL-IP (p = .007), BIM-IP (p < .001), and BIL-N (p = .004) in terms of speech-in-noise skills. In sound localization abilities, similar significant differences were found between the group of BIM-N and the groups of BIL-IP (p = .001), BIM-IP (p < .001), and BIL-N (p = .004). All groups showed statistically significant improvements in binaural condition on both tasks (p < .05).

CONCLUSION

We revealed that bilateral and bimodal pediatric CI users with IP-II benefitted from implantation as much as bilateral users with normal anatomy. Differences in residual hearing between groups may explain the poor performance of bimodal users with normal cochlear morphology. To the best of our knowledge, it is the first study to unveil binaural performance characteristics in children diagnosed with a specific inner ear malformation subgroup.

A 3-Year Follow-Up and Radiological Analysis of Cochlear Implantation Patients with Cochlear Nerve Deficiency and Modiolar Deficiency-Type Malformations

OBJECTIVE

Cochlear nerve deficiency (CND) is often combined with modiolar deficiency-type inner ear malformations, which cause variable cochlear implantation (CI) outcomes. We aimed to assess the postoperative development of auditory and speech perception in CND patients with modiolar deficiency-type malformations after 3 years of follow-up to determine the factors correlated with CI outcomes.

METHODS

Sixty-seven CND patients with modiolar deficiency-type malformations who underwent CI surgery were retrospectively reviewed. Modiolar deficiency-type malformations included common cavity (CC), cochlear hypoplasia (CH) (including CH-I and CH-II) and incomplete partition-I (IP-I). Categorical auditory performance (CAP) and the infant-toddler meaningful auditory integration scale (MAIS) were used to assess auditory ability. The speech intelligibility rating (SIR) and meaningful use of speech scale (MUSS) were used to assess the speech intelligibility of these CI patients. The CI outcomes were evaluated at 0, 12, 24 and 36 months after implant activation.

RESULTS

All patients demonstrated improvements in auditory ability and speech intelligibility after CI. There were no significant differences in CI outcomes at any time point according to the malformation type. The number of nerve bundles within the internal auditory canal (IAC) showed significant differences at 12, 24 and 36 months after CI ( p < 0.05). Patients with one nerve bundle had relatively poor CI outcomes.

CONCLUSIONS

CND patients with modiolar deficiency-type malformations showed continuous improvement in auditory and speech abilities after CI. Compared with malformations, the number of nerve bundles should be given more attention when selecting the side for CI.

Outcomes of Acoustic and Linguistic Performances Following Cochlear Implantation in Large Vestibular Aqueduct Syndrome (LVAS)

AIM

This study aims to collate the outcomes in acoustic and linguistic performances after cochlear implantation in LVAS.

METHODS

In a hospital-based prospective interventional study, seven prelingual children with bilateral profound sensorineural hearing loss (SNHL) with LVAS were recruited. They underwent unilateral cochlear implantation between December 2013 and December 2015 in the Department of Otorhinolaryngology and Head Neck Surgery at a tertiary care center. Outcomes of auditory and speech performances were assessed in the form of revised categories of auditory perception (CAP), infant toddler meaningful auditory integration scale (IT-MAIS) and speech intelligibility rating (SIR) scores preoperatively, at one and two years follow up.

RESULTS

The mean age of implantation was 4 years. The median revised CAP, IT-MAIS, and SIR scores after one and two years of follow-up were 6, 27, 3, and 11, 36, 5 respectively. The mean follow-up duration was 21.3 months.

CONCLUSION

Pre op median revised CAP, IT-MAIS, and SIR scores of 0, 1, 1 showed improvement to 11, 36, 5 at two years follow up which was statistically significant. Hence, we conclude that good functional outcomes post-operatively advocate the significance of cochlear implantation in LVAS.

Cochlear Implantation in Children with Enlarged Vestibular Aqueduct: A Systematic Review of Surgical Implications and Outcomes

OBJECTIVES

This study investigated age at implantation, improvement in hearing and speech perception outcomes, as well as surgical complications in pediatric cochlear implant recipients with Pendred Syndrome (PS) or non-syndromic enlarged vestibular aqueduct (NSEVA).

DESIGN

A systematic review of the literature between 1984 and 2021 was performed. Two independent reviewers performed abstract and full-text screening using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The inclusion criteria were: English language, cochlear implant, age at implantation available, age <18 years, PS, Mondini malformation, and enlarged vestibular aqueduct. Full-text analysis was completed using the National Institute of Health assessment tool for case series and case-control studies. Studies were also graded according to the Oxford Centre for Evidence-Based Medicine grading system.

RESULTS

In total, 198 studies were identified and screened, and 55 studies were included for analysis. Audiological outcomes were available in 46 studies, and the four-frequency pure-tone audiogram average improved by 60 to 78 dB HL due to cochlear implantation. Auditory performance and speech intelligibility scores increased by 44%. The overall average implantation age was 60 months. The implantation age was 21 months lower in the studies where individuals were implanted after the year 2000 compared with those implanted before the year 2000. Perilymph gusher/oozing was the most common surgical incident reported, occurring in 187 of 1572 implantations.

CONCLUSIONS

In children with PS/NSEVA, cochlear implantation improves pure-tone average by 60 to 78 dB HL and capacity of auditory performance/speech intelligibility by 44%. The implantation age for these children has decreased during the last two decades but is still somewhat higher than reported for unselected pediatric cochlear implantation. Perilymph gusher/oozing is the most common surgical complication.

Systematic review of cochlear implantation in patients with inner ear malformations

OBJECTIVES

To evaluate the outcomes of cochlear implantation in patients with severe to profound sensorineural hearing loss due to inner ear malformations (IEMs) when compared to patients without IEMs. We discussed audiological outcomes such as open-set testing, closed-set testing, CAP score, and SIR score as well as postoperative outcomes such as cerebrospinal fluid gusher and incomplete insertion rate associated with cochlear implantation in individuals with IEMs.

DATA SOURCES

PubMed, Science Direct, Web of Science, Scopus, and EMBASE databases.

REVIEW METHODS

After screening a total of 222 studies, twelve eligible original articles were included in the review to analyze the speech and hearing outcomes of implanted patients with IEMs. Five reviewers independently screened, selected, and extracted data. The "Tool to Assess Risk of Bias in Cohort Studies" published by the CLARITY group was used to perform quality assessment on eligible studies. Systematic review registration number: CRD42021237489.

RESULTS

IEMs are more likely to be associated with abnormal position of the facial nerve, raising the risk of intraoperative complications. These patients may benefit from cochlear implantation, but audiological outcomes may also be less favorable than in individuals without IEMs. Furthermore, due to the risk of cerebrospinal fluid gusher, incomplete insertion of electrodes, and postoperative facial nerve stimulation, surgeons can employ precautionary measures such as preoperative imaging and proper counseling. Postoperative imaging is suggested to be beneficial in ensuring proper electrode placement.

CONCLUSIONS

Cochlear implants (CIs) have the potential to provide auditory rehabilitation to individuals with IEMs. Precise classification of the malformation, preoperative imaging and anatomical mapping, appropriate electrode selection, intra-operative techniques, and postoperative imaging are recommended in this population.

Hearing-related quality of life assessment of pediatric cochlear implant users with inner ear malformations

OBJECTIVES

To assess the quality of life (QoL) in child and adolescent cochlear implant users with inner ear malformations (IEM) and to compare their outcomes to their cochlear implant using peers with normal inner ear structures.

METHODS

The present sample consisted of 100 children (45 with IEM, 55 without IEM) and 100 adolescents (46 with IEM, 54 without IEM). The following QoL questionnaires were used to assess the hearing-related QoL: The Hearing Environments and Reflection on Quality of Life 26 (HEAR-QL-26 for children between 7 and 12 years of age) and HEAR-QL-28 (for adolescents between 13 and 18 years of age). Both questionnaires were based on a 5-points Likert scale from 0 to 4, with higher scores indicating a better perception of QoL. The scores were converted to percentage values (never = 100, almost never = 75, sometimes = 50, often = 25, almost always = 0).

RESULTS

For the patients with IEM, mean scores from the HEAR-QL-26 and HEAR-QL-28 were 50.4 (SD = 18.9) and 54.5 (SD = 19.6), respectively. For the patients without IEM, mean scores from the HEAR-QL-26 and HEAR-QL-28 were 72.7 (SD = 18.0) and 65.0 (SD = 19.1), respectively. For both child and adolescent subgroups, statistically significant differences were observed between QoL scores from patients with and without IEM (p < 0.001). There were no statistically significant effects of the malformation type on the QoL findings (p ≥ 0.05).

CONCLUSION

Child and adolescent cochlear implant users with IEM had significantly lower scores on validated HEAR-QL versions in comparison to their implanted peers without IEM.

Cochlear and Vestibular Volumes in Inner Ear Malformations

A "gold standard" for quantitatively diagnosing inner ear malformations (IEMs) and a consensus on normative measurements are lacking. Reference ranges and cutoff values of inner ear dimensions may add in distinguishing IEM types. This study evaluates the volumes of the cochlea and vestibular system in different types of IEM.

STUDY DESIGN

Retrospective cohort.

SETTING

Tertiary academic center.

PATIENTS

High-resolution CT scans of 115 temporal bones (70 with IEM; cochlear hypoplasia [CH]; n = 19), incomplete partition (IP) Types I and III (n = 16), IP Type II with an enlarged vestibular aqueduct (Mondini malformation; n = 16), enlarged vestibular aqueduct syndrome (n = 19), and 45 controls.

INTERVENTIONS

Volumetry by software-based, semiautomatic segmentation, and 3D reconstruction.

MAIN OUTCOME MEASURES

Differences in volumes among IEM and between IEM types and controls; interrater reliability.

RESULTS

Compared with controls (mean volume, 78.0 mm3), only CH showed a significantly different cochlear volume (mean volume, 30.2 mm3; p < 0.0001) among all types of IEM. A cutoff value of 60 mm3 separated 100% of CH cases from controls. Compared with controls, significantly larger vestibular system volumes were found in Mondini malformation (mean difference, 22.9 mm3; p = 0.009) and IP (mean difference, 24.1 mm3; p = 0.005). In contrast, CH showed a significantly smaller vestibular system volume (mean difference, 41.1 mm3; p < 0.0001). A good interrater reliability was found for all three-dimensional measurements (ICC = 0.86-0.91).

CONCLUSION

Quantitative reference values for IEM obtained in this study were in line with existing qualitative diagnostic characteristics. A cutoff value less than 60 mm3 may indicate an abnormally small cochlea. Normal reference values for volumes of the cochlea and vestibular system may aid in diagnosing IEM.

Assessment of the correlation between residual hearing and audiologic outcomes after cochlear implantation in patients with cochlear nerve deficiency

Objective

This study aimed to assess the correlation between residual hearing and audiologic outcomes after cochlear implant (CI) surgery in patients with cochlear nerve deficiency (CND).

Methods

This retrospective study included 57 patients with CND who underwent CI surgery. Patients were divided into four groups according to hearing level (80–95, 95–110, 110–120, and >120 dB) and three groups according to residual hearing (entire spectrum hearing, partial spectrum hearing, and no spectrum hearing) based on the measured response at each frequency. Auditory performance (categorical auditory performance [CAP], Infant–Toddler Meaningful Auditory Integration Scale [IT‐MAIS]) and speech perception (speech intelligibility rating [SIR] and meaningful use of speech scale [MUSS]) were assessed before and 2 years after the surgery.

Results

Forty‐seven (82.5%) patients had complete or total hearing loss (≥95 dB) and 17 (29.8%) had no spectrum hearing before CI surgery. Twenty‐nine (50.9%) patients did not exhibit residual hearing at 4 kHz. All patients demonstrated an improvement in auditory performance and speech perception: the CAP score in the 80–95 dB group was significantly higher than that in the 110–120 and >120 dB groups, and the entire spectrum hearing group showed significantly higher CAP, SIR, and IT‐MAIS scores than the partial spectrum hearing group and significantly higher CAP, SIR, IT‐MAIS, and MUSS scores than the no spectrum hearing group.

Conclusion

For patients with CND, residual hearing, especially high‐frequency residual hearing, was poor and postoperative audiologic outcomes were significantly associated with the range of residual hearing.

Level of Evidence

4

Cochlear base length as predictor for angular insertion depth in incomplete partition type 2 malformations

INTRODUCTION

The preoperative determination of suitable electrode array lengths for cochlear implantation in inner ear malformations is a matter of debate. The choice is usually based on individual experience and the use of intraoperative probe electrodes. The purpose of this case series was to evaluate the applicability and precision of an angular insertion depth (AID) prediction method, based on a single measurement of the cochlear base length (CBL).

METHODS

We retrospectively measured the CBL in preoperative computed tomography (CT) images in 10 ears (8 patients) with incomplete partition type 2 malformation. With the known electrode length (linear insertion depth, LID) the AID at full insertion was retrospectively predicted for each ear with a heuristic equation derived from non-malformed cochleae. Using the intra- or post-implantation cone beam CT images, the actual AID was assessed and compared. The deviations of the predicted from the actual insertion angles were quantified (clinical prediction error) to assess the precision of this single-measure estimation.

RESULTS

Electrode arrays with 15 mm (n = 3), 19 mm (n = 2), 24 mm (n = 3), and 26 mm (n = 2) length were implanted. Postoperative AIDs ranged from 211° to 625°. Clinical AID prediction errors from -64° to 62° were observed with a mean of 0° (SD of 44°). In two ears with partial insertion of the electrode, the predicted AID was overestimated. The probe electrode was intraoperatively used in 9/10 cases.

CONCLUSION

The analyzed method provides good predictions of the AID based on LID and CBL. It does not account for incomplete insertions, which lead to an overestimation of the AID. The probe electrode is useful and well established in clinical practice. The investigated method could be used for patient-specific electrode length selection in future patients.

Effect of inner ear malformations on intraoperative ECAP thresholds and postoperative auditory performance

Objectives

This study sought to characterize the influence of inner ear malformations (IEMs) on intraoperative electrically evoked compound action potential (ECAP) and auditory performance to better understand the underlying pathophysiology related to variabilities in cochlear implant (CI) outcomes that individuals with malformed cochlea may present.

Methods

The medical records of 222 ears implanted with Cochlear Nucleus CI were reviewed. Of the total, 64 ears had radiologic evidence of IEMs, and 158 ears were normal. Individuals with IEMs were grouped based on the severity of anomalies; 38 had mild IEMs (e.g., enlarged vestibular aqueduct, incomplete partition type II, etc.) and 26 had severe IEMs (e.g., cochlear nerve hypoplasia, common cavity, etc.). Intraoperative ECAP thresholds obtained via neural response telemetry (NRT) and the categories of auditory performance (CAP) scores measured at 12 months postoperative were compared and correlated.

Results

Absent ECAP responses were more apparent in the IEM group. ECAP thresholds were significantly elevated in the severe IEM group, while the mild IEM group had ECAP thresholds comparable to the normal group. The mild IEM group achieved CAP scores similar to the normal control. Patients in the severe IEM group showed significantly lower CAP scores at 12 months postoperative. Significant negative relationships existed between ECAP thresholds and CAP scores obtained from all subjects.

Conclusion

Measurable ECAP responses and NRT thresholds varied across groups. The inverse relationship between NRT thresholds and CAP scores may suggest that electrophysiological responses measured during surgery may potentially be indicative of postoperative performance in our CI population.

Level of Evidence

2b.

Cochlear Implantation in Inner Ear Malformations: Considerations Related to Surgical Complications and Communication Skills

INTRODUCTION

There are particular challenges in the implantation of malformed cochleae, such as in cases of facial nerve anomalies, cerebrospinal fluid (CSF) leaks, erroneous electrode insertion, or facial stimulation, and the outcomes may differ depending on the severity of the malformation. The aim of this study was to assess the impact of inner ear malformations (IEMs) on surgical complications and outcomes of cochlear implantation.

METHODS

In order to assess the impact of IEMs on cochlear implant (CI) outcomes, 2 groups of patients with similar epidemiological parameters were selected from among 863 patients. Both the study group (patients with an IEM) and control group (patients with a normal inner ear) included 25 patients who received a CI and completed at least 1 year of follow-up. Auditory performance, receptive and expressive language skills, and production and use of speech were evaluated preoperatively and at least 1 year after implantation. Types of surgical complications and rates of revision surgeries were determined in each group.

RESULTS

In the study group, the most common malformation was an isolated enlarged vestibular aqueduct (EVA) (44.8%). Overall, the patients with IEMs showed significant improvement in auditory-verbal skills. In general, the patients who had normal cochleae scored significantly better compared to patients with IEMs (p < 0.05). The complication rate was significantly lower in the control group compared to the study group (p = 0.001), but the rate of revision surgeries did not differ significantly (p = 0.637).

CONCLUSION

It is possible to improve communication skills with CIs in patients with IEMs despite the variations in postoperative performances. Patients with EVA, incomplete partition type 2, and cochlear hypoplasia type 2 were the best performers in terms of auditory-verbal skills. Patients with IEMs scored poorly compared to patients with normal cochleae. CSF leak (gusher or oozing) was the most common complication during surgery, which is highly likely in cases of incomplete partition type 3.

Complications of Cochlear Implant Surgery: A Public Implant Centre Experience

Objectives:

To determine the prevalence of complications of cochlear implant surgery in children with congenital profound sensorineural hearing loss.

Methods:

This study retrospectively & consecutively reviewed charts of children who underwent cochlear implantation from July 2015 to July 2019 at Cochlear Implant Centre of Otolaryngology Department of Capital Hospital, Islamabad Pakistan. These included cases of both genders aged one to 12 years operated at least one year before the time of data collection. Basic demographic data, complications including major and minor complications and treatment received was noted and statistically analyzed using SPSS-23. Results were presented using descriptive statistics.

Results:

Current study included a sample of N=251 having a mean age of 4.05±2.15 years including 154(61.4%) males and 97(38.6%) females revealed a prevalence of complications of 16(6.4%) with 4(1.6%) major and 12(4.8%) minor complications. Wound infection and acute otitis media with frequency of 3(1.2%) each were the commonest complications, followed by , facial nerve twitching, tinnitus and vertigo, infection and extrusion; and device failure in 2(0.8%) each. However, there was no significant association of complications with age group and gender with P=0.344 and P=0.519 respectively.

Conclusion:

Present public sector implant program is characterized with a very low prevalence of complications of 16(6.4%) with 4(1.6%) major and 12(4.8%) minor complications. Wound infection and acute otitis media were the commonest complications.

Sequential Bilateral Cochlear Implantation in a Child with Severe External, Middle, and Inner Ear Malformations: Surgical Considerations and Practical Aspects

Cochlear implantation (CI) is a safe and beneficial surgery for children with congenital inner ear malformations, with the exception of cochlear nerve aplasia. The combination of microtia with middle and inner ear abnormalities is extremely uncommon and sufficiently severe to make a surgical approach to the cochlea difficult. We report herein the case of a 2-year-old girl who presented with profound bilateral sensorineural hearing loss, congenital aural atresia, microtia, and inner ear malformations. High-resolution computed tomography revealed poor development of the bilateral middle ear spaces, absence of the incus and stapes, aberrant courses of facial nerves, aplastic lateral semicircular canals, and covered round windows. With intraoperative imaging assistance, sequential bilateral CI was performed using a transmastoid approach with no complication. We propose that CI is feasible in patients with severe external and middle ear malformations. However, major malformations increase the risk of complications. As the facial nerve and cochlea are difficult to locate due to the lack of important anatomical landmarks, detailed planning and adequate preparation, including review of the preoperative imaging data, and the use of facial nerve monitoring and intraoperative imaging are very important. In addition, experienced surgeons should perform CI to ensure the success of the operation.

Cochlear Implantation in Pediatric Patients With Enlarged Vestibular Aqueduct: A Systematic Review

OBJECTIVE(S)

To describe cochlear implantation (CI) outcomes, with speech perception, auditory, language, and parent-reported auditory and speech behaviors, in children with an enlarged vestibular aqueduct (EVA) and incomplete partition type 2 (IP-II) and compare to control children without inner ear malformations (IEMs) and to determine cerebrospinal fluid gusher rates and effect on outcomes.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, Embase, Cochrane, and CINAHL databases were searched from inception to February 2020. Studies reporting relevant outcomes in children with EVA or EVA + IP-II and controls without IEMs undergoing CI were included. Mean differences in speech perception, auditory, and language scores between cases and controls were meta-analyzed. Gusher rates were determined by proportion meta-analyses.

RESULTS

Of 214 identified articles, 42 met inclusion criteria, evaluating 775 cases and 2,191 controls. Of -cases, 578 (74.6%) had EVA and 197 (25.4%) had EVA + IP-II. Cases showed a significant improvement in speech perception, auditory and language performance, comparable to controls. Parent-reported auditory and speech production behaviors outcomes were positive among cases and comparable to controls. Pooled gusher proportions in EVA and EVA + IP-II cases were 27.7% (95% CI: 17.6-39.1) and 48.6% (95% CI: 28.6-69.0), respectively, with a proportion difference of 20.9% (95% CI: 11.0-30.1). Gusher occurrence did not impact speech perception or language outcomes.

CONCLUSION

Outcomes in children with EVA or EVA + IP-II undergoing CI are favorable and largely comparable to outcomes in children with hearing loss undergoing CI without IEMs. Intraoperative gusher is more prevalent among children with EVA + IP-II as compared to iEVA. Gusher does not influence speech perception and language development outcomes.

LEVEL OF EVIDENCE

NA Laryngoscope, 2021.

New Classification of Cochlear Hypoplasia Type Malformation: Relevance in Cochlear Implantation

OBJECTIVES

This paper attempts to create a new classification type of cochlear hypoplasia (CH)-type malformation taking into consideration of vestibular section and internal auditory canal (IAC).

MATERIALS AND METHODS

Preoperative computed-tomography (CT) scans of cochlear implant (CI) candidates (N=31) from various clinics across the world with CH type malformation were taken for analysis. CT dataset were loaded into 3D-slicer freeware for three-dimensional (3D) segmentation of the inner-ear by capturing complete inner-ear structures from the entire dataset. Cochlear size in terms of diameter of available cochlear basal turn and length of cochlear lumen was measured from the dataset. In addition, structural connection between IAC and cochlear portions was scrutinized, which is highly relevant to the proposed CH classification in this study.

RESULTS

CH group-I has the normal presence of IAC leading to cochlear and vestibular portions, whereas CH group-II is like CH group-I but with some degree of disruption in vestibular portion. In CH group-III, a disconnection between IAC and the cochlear portion irrespective of other features. Within all these three CH groups, the basal turn diameter varied between 3.1 mm and 9.6 mm, and the corresponding cochlear lumen length varied between 3 mm and 21 mm for the CI electrode array placement.

CONCLUSION

A new classification of CH mainly based on the IAC connecting the cochlear and vestibular portions is presented in this study. CI electrode array length could be selected based on the length of the cochlear lumen, which can be observed from the 3D image.

Cochlear Implantation in Cases of Inner Ear Malformation: A Novel and Simple Grading, Intracochlear EABR, and Outcomes of Hearing

OBJECTIVE

To propose a simple grading of inner ear malformation (IEM) and investigate intracochlear electrical auditory brainstem response (EABR) and outcomes for hearing in terms of the novel grading system.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Sixty patients with IEMs who received cochlear implants.

INTERVENTION

Grading according to observation of modiolus deficiency and/or internal auditory canal (IAC) cochlear nerve deficiency (CND).

MAIN OUTCOME MEASURE

Intracochlear EABR and categories of auditory performance (CAP) scores were assessed; children in school were categorized according to the type of school attended.

RESULTS

Among 60 patients, 38% were classified as Grade I (modiolus present + normal cochlear nerve), 22% as grade II (modiolus deficiency + normal cochlear nerve), 33% as grade III (modiolus present + IAC CND), and 7% as grade IV (modiolus deficiency + IAC CND). During the operation, 93% of Grade I, 36% of Grade II, 23% of Grade III, and 50% of Grade IV patients showed typical EABR waves. CAP scores of 4 or more were obtained from 91% of Grade I, 62% of Grade II, 35% of Grade III, and 25% of Grade IV. Whereas none of children in Grades III and IV entered main stream school, 55% of Grade I and 25% of Grade II entered mainstream schools.

CONCLUSIONS

Outcomes of hearing with cochlear implantations in IEM children depend on the severity of IEM and IAC CND. Our novel grading of IEM is simple and can be useful for understanding the severity of IEM.

Audiologic Outcomes of Cochlear Implantation in Cochlear Malformations: A Comparative Analysis of Lateral Wall and Perimodiolar Electrode Arrays

OBJECTIVE

Cochlear implantation in children with inner ear malformations has been shown to be beneficial. The aims of this study are to evaluate open set word recognition outcomes among children with cochlear implants who have cochlear malformations, and to further assess if either the lateral wall (LW) or perimodiolar (PM) electrode arrays confer any performance outcome advantages.

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary referral center.

PATIENTS

Pediatric cochlear implant recipients with cochlear malformations who were implanted at our institution within the last 10 years and had speech perception scores were eligible for inclusion in the study. Potential participants were excluded if they had less than 1 year of listening experience with the cochlear implant or suspected cochlear nerve deficiency.

INTERVENTION

None.

MAIN OUTCOME MEASURE

Most recent consonant-nucleus-consonant word score.

RESULTS

ANOVA analysis demonstrated that the type of cochlear malformation was significantly associated with speech perception outcome (p = 0.006). Those with IP2 malformations had significantly better word recognition outcomes than the remaining cochlear malformations. Array type (LW or PM) was not associated with better word recognition outcomes in long-term follow-up of patients with IP2 malformations (p = 0.13).

CONCLUSIONS

In children who have cochlear malformations, cochlear implantation results in varying word recognition outcomes based on the type of malformation. While the participants in this study demonstrated postoperative open set word recognition skills, those with IP2 malformations demonstrated the most benefit. Electrode type was not found to significantly impact outcomes in this cohort.

Screening Strategies for Deafness Genes and Functional Outcomes in Cochlear Implant Patients

OBJECTIVES

To review the current state of knowledge about the influence of specific genetic mutations that cause sensorineural hearing loss (SNHL) on cochlear implant (CI) functional outcomes, and how this knowledge may be integrated into clinical practice. A multistep and sequential population-based genetic algorithm suitable for the identification of congenital SNHL mutations before CI placement is also examined.

DATA SOURCES, STUDY SELECTION

A review was performed of the English literature from 2000 to 2019 using PubMed regarding the influence of specific mutations on CI outcomes and the use of next-generation sequencing for genetic screening of CI patients.

CONCLUSION

CI is an effective habilitation option for patients with severe-profound congenital SNHL. However, it is well known that CI outcomes show substantial inter-patient variation. Recent advances in genetic studies have improved our understanding of genotype-phenotype relationships for many of the mutations underlying congenital SNHL, and have explored how these relationships may account for some of the variance seen in CI performance outcomes. A sequential genetic screening strategy utilizing next-generation sequencing-based population-specific gene panels may allow for more efficient mutation identification before CI placement. Understanding the relationships between specific mutations and CI outcomes along with integrating routine comprehensive genetic testing into pre-CI evaluations will allow for more effective patient counseling and open the door for the development of mutation-specific treatment strategies.

Prevalence & features of inner ear malformations among children with congenital sensorineural hearing loss: A Public Cochlear Implant Centre Experience

OBJECTIVE

To determine the prevalence and features of inner ear anomalies in children with congenital profound hearing loss who presented at our cochlear implant center based on imaging studies.

METHODS

This retrospective study reviewed charts of children with congenital SNHL, who presented to Department of Otolaryngology & Auditory Implant Centre, Capital Hospital Islamabad over a period of 2 years from 1^st May 2017 to 30^th April 2019. These included 481 cases of both genders aged between 1 to 12 years. After gathering demographic data, audiological data, computed tomography findings of the temporal bone were analyzed. Data was analyzed using SPSS 22.

RESULTS

The Inner Ear Malformations were identified in 48(10%) children including 28 (58.33%) males and 20 (41.67%) female. Most 20(41.67%) presented at >3-5 years of age followed by 19(39.58%) at 2-3 years. However, no significant association of gender (p=0.57, p=0.076) and age of presentation (p=0.344, p=0.697) for right and left ears was noted with inner ear malformations. The most common anomaly noted were CLA, CH-III and CH-II in decreasing order of frequency in both ears.

CONCLUSION

The prevalence of IEM's was found to be 48(10%). Commonest anomalies noted were CLA, CH-III and CH-II. No significant association of gender and age of presentation was noted with type of anomaly in both ears.

FORM24 electrode array and perioperative cerebrospinal fluid leakage in cochlear implant recipients with cochleovestibular malformations

BACKGROUND

Cochlear implant (CI) recipients with a cochleovestibular malformation (CVM) are at a higher risk of experiencing an intra-operative cerebrospinal fluid (CSF) gusher and, therefore are at greater risk of developing postoperative meningitis than are CI recipients with normal cochlear anatomy. To control CSF gushers, the FORM electrode array was developed.

OBJECTIVES

To assess the ability of the FORM24 electrode array in managing intraoperative CSF gushers and preventing postoperative CSF leakage in a population of CI recipients.

DESIGN

Retrospective.

SETTING

Tertiary health care center.

PATIENTS AND METHODS

All CIs in which a FORM24 was used between January 2014 and March 2018 were reviewed for demographic and safety results.

MAIN OUTCOME MEASURES

Safety results were assessed as the intraoperative or postoperative presence of an episode of CSF leakage or meningitis.

SAMPLE SIZE

177 CI recipients.

RESULTS

Thirty-six (20.3%) had a CVM and 141 had normal anatomy (79.7%). Of the 36 participants with a CVM, 20 (55.6%) experienced an intraoperative CSF gusher, all of which were resolved. No cases of postoperative leakage or meningitis were recorded after a mean follow-up time of 36 months.

CONCLUSION

The FORM24 array is able to help surgeons stop intraoperative CSF gushers and prevent postoperative CSF leakage and meningitis in CI recipients with a CVM.

LIMITATIONS

Further studies are needed.

CONFLICT OF INTEREST

None.

A New Pathogenic Variant in the TRIOBP Associated with Profound Deafness Is Remediable with Cochlear Implantation

BACKGROUND AND OBJECTIVES

A rare type of nonsyndromic autosomal recessive hereditary hearing loss is caused by pathogenic mutations in the TRIOBP gene mostly involving exons 6 and 7. These mutations cause hearing loss originating from dysfunction of sensory inner ear hair cells. Of all the affected siblings, 2 brothers and 1 sister, part of an Afghan family, were referred to our clinic for diagnostic workup and candidacy selection for cochlear implantation (CI).

METHODS

Molecular analysis showed a homozygous c.1342C > T p. (Arg448*) pathogenic variant in exon 7 of the TRIOBP gene (reference sequence NM_001039141.2) in all 3 affected siblings. Clinical audiometry demonstrated profound sensorineural hearing loss in all 3 affected siblings (2 males and 1 female), and they were implanted unilaterally.

RESULTS

One month after activation, the pure-tone averages with the CI processor were between 30 and 23 dBHL. Ten months after the first activation of the implant, open-set speech audiometry test could be performed for the first time in the 2 younger CI recipients (S5 and S9), and they could identify up to a maximum 77% phonemes correctly. The oldest brother (S12) could not yet perform open-set speech audiometry at that moment.

CONCLUSIONS

Implant outcomes are better with normal inner ear anatomy in general. The earlier congenital patients are implanted, the better their outcomes. Here, we demonstrate both statements are true in a homozygous c.1342C > T p. (Arg448*) pathogenic variant in the TRIOBP gene in all 3 affected siblings.

Evaluation of Subtotal Petrosectomy Technique in Difficult Cases of Cochlear Implantation

OBJECTIVES

To assess the validity of the subtotal petrosectomy (STP) technique in problematic cases of cochlear implant (CI) surgery, and review indications, outcomes, and related controversies.

STUDY DESIGN

This is a retrospective review of data from a private quaternary referral center of otology and skull base surgery.

PATIENTS AND METHODS

A review of patients who underwent CI with STP (STP-CI) as the leading approach was performed. Demographics, indications, surgical details, and main outcomes were evaluated. The surgeries performed were usually single-stage procedures encompassing a comprehensive mastoidectomy, blind sac closure of the external auditory canal (EAC), and mastoid obliteration with autologous fat.

RESULTS

A total of 107 cases were included. Mean follow-up was 7.1 years (range 1-13 years). The most frequent indication for STP-CI was chronic otitis media with/without cholesteatoma (32.7%), followed by open mastoid cavity (26.1%), and cochlear ossification (17.7%). Other difficult conditions where STP facilitates successful implantation include inner-ear malformations, temporal-bone trauma, unfavorable anatomic conditions, and revision surgery. A planned staged procedure was performed in 3 cases. The rate of major complications was 5.6% (n = 6). Three patients developed postauricular wound dehiscence which eventually resulted in device extrusion. No cases of recurrent/entrapped cholesteatoma, EAC breakdown, or meningitis were encountered. This is the largest single-center series of STP-CI reported in the literature.

CONCLUSIONS

When CI is intended in technically challenging cases or associated with a high risk of complications, STP is effective and reliable. Safe implantation and excellent long-term outcomes can be achieved provided surgical steps are properly followed. Single-stage procedures can be performed in most cases, even when there is active middle-ear disease.

Cochlear implantation in children with inner ear malformation: A multicenter study on auditory performance and speech production outcomes

OBJECTIVES

This multicenter study evaluated the auditory performance and speech production outcomes of cochlear implantation in children with inner ear anomaly and compared the outcomes of patients with different kinds of malformation.

METHODS

Cochlear implantation was performed in 107 children with inner ear malformation at four tertiary academic centers. The categories of auditory performance (CAP) and speech intelligibility rating (SIR) scores were evaluated preoperatively and one year and two years postoperatively.

RESULTS

Types of inner ear malformation and their frequencies were: incomplete partition type-I, 19 (17.8%) patients; incomplete partition type-II, 31 (29%), common cavity, 17 (15.9%), cochlear hypoplasia, 17 (15.9%), and isolated enlarged vestibular aqueduct (isolated EVA), 23 (21.5%) patients. EVA was the coexisting anomaly in 27(25.2%) subjects. The median CAP and SIR scores improved significantly during the first two years after cochlear implantation in all groups (p-values <0.001 and < 0.001, respectively). No significant difference was seen in CAP and SIR scores of children with different inner ear malformations (p-value = 0.147 and 0.570, respectively) or in patients with isolated EVA compared to coexisting EVA (p-value = 0.538 and 0.075, respectively).

CONCLUSION

The median CAP and SIR scores two years after surgery were 5 (Understanding of common phrases without lip-reading) IQR: 4-6, and 3 (Connected speech is intelligible to a listener who concentrates and lip-reads within a known context) IQR: 3-4, respectively. Auditory performance and speech production were significantly improved in all inner ear malformation patient groups, and no significant difference was observed between the scores of patients with different types of anomaly.

Cochlear Implant

Cochlear implant is the first approved cranial nerve stimulator that works by directly stimulating the cochlear nerve. The medical and societal impact of this revolutionary device cannot be understated. This article reviews the evolving indications for cochlear implant, patient assessment, surgical approach, and outcomes for pediatric and adult cochlear implant that demonstrate its impact. Future concepts in cochlear implant are introduced briefly. This article covers a breadth of information; however, it is not intended be entirely comprehensive. Rather, it should serve as a foundation for understanding cochlear implant.

A de novo SIX1 variant in a patient with a rare nonsyndromic cochleovestibular nerve abnormality, cochlear hypoplasia, and bilateral sensorineural hearing loss

Background

Childhood hearing impairment affects language and cognitive development. Profound congenital sensorineural hearing impairment can be due to an abnormal cochleovestibular nerve (CVN) and cochleovestibular malformations, however, the etiology of these conditions remains unclear.

Methods

We used a trio‐based exome sequencing approach to unravel the underlying molecular etiology of a child with a rare nonsyndromic CVN abnormality and cochlear hypoplasia. Clinical and imaging data were also reviewed.

Results

We identified a de novo missense variant [p(Asn174Tyr)] in the DNA‐binding Homeodomain of SIX1, a gene which previously has been associated with autosomal dominant hearing loss (ADHL) and branchio‐oto‐renal or Branchio‐otic syndrome, a condition not seen in this patient.

Conclusions

SIX1 has an important function in otic vesicle patterning during embryogenesis, and mice show several abnormalities to their inner ear including loss of inner ear innervation. Previous reports on patients with SIX1 variants lack imaging data and nonsyndromic AD cases were reported to have no inner ear malformations. In conclusion, we show that a de novo variant in SIX1 in a patient with sensorineural hearing loss leads to cochleovestibular malformations and abnormalities of the CVN, without any other abnormalities. Without proper interventions, severe to profound hearing loss is devastating to both education and social integration. Choosing the correct intervention can be challenging and a molecular diagnosis may adjust intervention and improve outcomes, especially for rare cases.

Cochlear implantation in incomplete partition type I

OBJECTIVES

To share our experience in cochlear implanted patients with incomplete partition type I, to compare it with the literature results and to disclose difficulties facing cochlear implant teams dealing with these patients.

MATERIALS AND METHODS

Clinical records of 1089 cochlear implant procedures in a cochlear implant center were reviewed and data of patients who had incomplete partition type I were enrolled in this study. Their auditory and speech performances were evaluated 3 years after the implantation.

RESULTS

Eighteen cases (1.65%) had incomplete partition type I. Cerebrospinal fluid gusher was encountered during opening the cochlea in 15 patients (83.3%). There were no cases of persistent CSF leak or postoperative meningitis. In 61.1% of patients, some additional anomalies were found during the operation. Although in 55.6% of cases no electrically evoked compound action potential was detected even in long-term follow-up, all patients had satisfactory auditory and speech outcome.

CONCLUSION

Cochlear implantation is a relatively safe and effective treatment for patients who have incomplete partition type I, even if the procedure may be somehow challenging.

Outcome of Cochlear Implantation in Children With Narrow Bony Cochlear Nerve Canal

OBJECTIVE

To investigate the diameter of the bony cochlear nerve canal (BCNC) as a prognostic indicator of cochlear implantation (CI) in children.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

Two hundred ninety two prelingual deaf children (323 ears) who received CI before the age of 5 years.

INTERVENTIONS

CI in pediatric patients.

MAIN OUTCOME AND MEASURES

Postoperative auditory performance was analyzed according to the diameter of the BCNC using the Mann-Whitney U test. Using the images of temporal bone computed tomography, patients were grouped according to the diameter of the BCNC: narrow (<1.4 mm, Group 1), normal (Group 2), and other anomalies (Group 3).

RESULTS

Group 1 (10.5%) showed a less significant degree of improvement in category of audiological performance (CAP) score than Groups 2 (57.3%) and 3 (32.2%). Scores obtained from both the open-set monosyllabic words and sentence tests were lower in Group 1 than Groups 2 and 3. Of the patients with narrow BCNC, the CAP score of patient with complete stenosis of BCNC (<0.2 mm) was lower than that of patients with BCNC between 0.2 and 0.8 mm, also 0.8 and 1.4 mm.

CONCLUSIONS

The improvement in auditory performance was limited in children with narrow BCNC and the narrower the BCNC, the more severe the limitation. However, gradual improvement can be expected and even children with narrow BCNC may be candidates for early CI and rehabilitation.

Outcomes of cochlear implantation in children with inner ear malformations

PURPOSE

To evaluate the surgical experience and auditory functions and progress of speech development of cochlear implantation in malformed ears.

MATERIALS AND METHODS

Between November 1995 and July 2017, thirty-seven patients (26 females and 11 males; mean age: 138.275 ± 96.24 months) with diverse anomalies of the inner ear were retrospectively examined for surgical and audiological results. Speech Intelligibility Rating (SIR), Categories of Auditory Perception (CAP), Pure Tone Average (PTA), Speech Intelligibility Rating (SRT), and Word Discrimination Score (WDS) were the audiological tests used to evaluate the efficacy of CI in the malformed inner ears.

RESULTS

CSF gusher was experienced by six patients (three with LVA (large vestibular aqueduct), one with IP (incomplete partition) I, and two with both IP II Mondini malformations and LVA). Two patients had transient facial paresis after surgery. All patients fully recovered within 6 months. The postoperative PTA, SRT, and WDS test results showed significant differences between progressive and congenital sensorineural hearing loss (p values < 0.05 for all). On the other hand, the postoperative CAP and SIR test results revealed no significant differences between the two groups. According to etiology, the PTA and SRT values were significantly lower in common cavity patients than the LVA patients (p values < 0.01); no significant differences were found among the other etiological groups.

CONCLUSIONS

Cochlear implantation is safe in children with inner ear malformations. However, the success rate is low compared to patients with normal anatomy in terms of audiological results; the most successful group of patients with inner ear malformation is large vestibular aqueduct.

Speech development in young children with Mondini dysplasia who had undergone cochlear implantation

OBJECTIVE

The purpose of this study was to investigate the development of speech skills in young children with Mondini dysplasia and age-matched deaf children with radiologically normal inner ears over a period of 5 years after cochlear implantation (CI).

METHODS

In total, 700 congenitally severely to profoundly deaf children (281 girls and 419 boys) participated in this study. All of the participants had undergone unilateral CI surgery before 36 months of age. The participants were categorized into two groups based on the absence or presence of Mondini dysplasia in the implanted ear, as assessed via high-resolution, thin-slice computerized tomography or magnetic resonance imaging: group A comprised 592 children with radiologically normal inner ears and group B comprised 108 children with Mondini dysplasia. The Meaningful Use of Speech Scale (MUSS) and Speech Intelligibility Rating (SIR) were used to evaluate the speech performance of all young children at various time points: pre-surgery and at 1, 3, 6, 12, 24, 36, 48, and 60 months after switch-on programming.

RESULTS

The mean scores of SIR and MUSS in children from both group A and group B showed significant improvements over time. No significant differences were found in the mean scores of SIR between the two groups at any time interval during the 5-year follow-up. The mean score of MUSS was significantly different between group A and group B at 12, 24, and 36 months after implantation, whereas no obvious differences were noted pre-surgery, and at 1, 3, 6, 48, and 60 months post-operation.

CONCLUSIONS

Young children with Mondini dysplasia develop their speech skills at a fast rate and achieve similar speech acquisition compared to age-matched children with radiologically normal inner ears 5 years post-operation. Therefore, CI is an effective intervention method for young children with Mondini dysplasia.

Comparable Electrode Impedance and Speech Perception at 12 Months after Cochlear Implantation Using Round Window versus Cochleostomy: An Analysis of 40 Patients

OBJECTIVE

The objective of this study was to examine whether cochlear implantation using the round window (RW) route versus cochleostomy achieves comparable electrode impedance and hearing results.

METHODS

This retrospective analysis included 40 patients receiving a cochlear implant (REZ-1): 20 using the RW approach and the remaining 20 using cochleostomy. Electrode impedance and tone, vowel, consonant, disyllable and sentence perception were measured during and after the implantation.

RESULTS

Electrode impedance did not differ significantly between the 2 groups at any time points [F(1, 38) = 1.84; p = 0.184]: 1.87, 5.16, 6.47 and 6.70 kΩ in the RW group versus 2.86, 5.33, 6.92 and 8.16 kΩ in the cochleostomy group at 0, 1, 3 and 12 months, respectively. There was no significant difference between the RW and cochleostomy groups for tone (77.50 vs. 80.50%; p = 0.472), vowel (77.70 vs. 78.65%; p = 0.760), consonant (75.50 vs. 78.25%; p = 0.443), disyllable (78.60 vs. 81.50%; p = 0.317) and sentence (50.90 vs. 52.50%; p = 0.684) perception at 12 months.

CONCLUSION

The RW approach is comparable to cochleostomy in electrode placement as reflected by impedance and function as reflected by tone, vowel, consonant, disyllable and sentence perception.