Cochlear Implantation in Children with Inner Ear Malformations

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.

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.

The Risk of Meningitis After Cochlear Implantation: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aims to estimate the rate of postoperative meningitis (both immediate and long-term) in patients following cochlear implants (CIs). It aims to do so through a systematic review and meta-analysis of published studies tracking complications after CIs.

DATA SOURCES

MEDLINE, Embase, and Cochrane Library.

REVIEW METHODS

This review was performed in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies tracking complications following CIs in patients were included. Exclusion criteria included non-English language studies and case series reporting <10 patients. Bias risk was evaluated using the Newcastle-Ottawa Scale. Meta-analysis was performed through DerSimonian and Laird random-effects models.

RESULTS

A total of 116/1931 studies met the inclusion criteria and were included in the meta-analysis. Overall, there were 112 cases of meningitis in 58,940 patients after CIs. Meta-analysis estimated an overall rate of postoperative meningitis of 0.07% (95% confidence interval [CIs], 0.03%-0.1%; I2  = 55%). Subgroup meta-analysis showed this rate had 95% CIs crossing 0% in implanted patients who received the pneumococcal vaccine, antibiotic prophylaxis, those with postoperative acute otitis media (AOM), and those implanted less than 5 years.

CONCLUSION

Meningitis is a rare complication following CIs. Our estimated rates of meningitis after CIs appear lower than prior estimates based on epidemiological studies in the early 2000s. However, the rate still appears higher than the baseline rate in the general population. The risk was very low in implanted patients who received the pneumococcal vaccine, antibiotic prophylaxis, received unilateral or bilateral implantations, developed AOM, those implanted with a round window or cochleostomy techniques, and those under 5 years.

Audiological and Speech Outcomes of Cochlear Implantation in Inner Ear Malformation Compared to the Normal Inner Ear

To compare the overall clinical outcomes of cochlear implantation in children with structural inner ear abnormalities, with results of implantation in children with radiologically 'normal' inner ears. To study the incidence and performance outcomes of cochlear implantation in children with inner ear malformations (IEMs). It is a retrospective case control study of 57 normal and 57 abnormal inner ear patients operated for cochlear implant between Jan 1, 2014 and Aug 1, 2017, by Veria technique. The age range was between 12 months and 15 years. The prevalence of IEMs was 13.8%. Of the 57 cases with IEMs, 33.3% were of enlarged vestibular acqueduct, 7% were of isolated Incomplete Partition type-2, 21.1% cases were of Mondini's dysplasia, 3.5% of Incomplete partition type-1 and 8.8% of cochlear nerve hypoplasia. Most commonly encountered malformation was EVA while IP-1 was the least common malformation. A CSF gusher was experienced in 11 cases. There was a statistically significant difference between the CAP and SIR scores of both IEM and control groups, both at 1 year and at 2 years (1 year CAP score p value < 0.001, 2 year CAP score p value 0.002 and 1 year SIR score, p value < 0.001, 2 year SIR score, p value 0.013). There was progressive improvement in the scores (of both groups) at the 2 year mark, compared to 1 year scores. Cochlear implantation is safe and surgically feasible in children with IEMs. However, the hearing outcome and speech perception outcomes are poor than those of patients with normal anatomy, with an exception seen in enlarged vestibular aqueduct.

Our Experience in 576 Cases of Cochlear Implant Surgery by Veria Technique

OBJECTIVE

To study and analyse the result obtained in cochlear implantation by Veria technique and evaluate the incidence of surgical complications and their management.

METHOD

Between Jan 1, 2014 to Jan 1, 2019, 602 cochlear implantations by Veria technique were done out of which 576 patients were analysed retrospectively for the study. The age range was between 18 months and 60 years.

RESULT

All 576 patients were operated by Veria technique. Out of 576 patients, 57 (9.9%) had abnormal cochlear malformation. Cytomegalovirus (CMV) being the most common non genetic cause of congenital hearing loss accounting to 60%. The overall complication rate of 5.5% was observed in 576 implanted patients.

CONCLUSION

The analysis of the results shows that this method has certain advantages, which are: it is simple and therefore the learning curve is fast; it is safe for the facial nerve, as the drilling is precisely controlled by the special perforator; it produces minimal bone trauma and due fast healing, it permits early fitting a few days after operation; it can be used for very small children where the mastoid may have not been yet sufficiently developed.

Cochlear Implant Induced Labyrinthine Ossificans in Mondini Malformation: A Case Series

Cochlear implantation is relatively a safe procedure with a favorable outcome. Labyrinthine ossification is one of the rare complications that has been observed in some occasions post-cochlear implantation. This paper report two cases of Mondini inner ear malformation cochlear implant failure associated with labyrinthine ossification, mandating revision surgery, and a literature review focusing on the reported cases, risk factors, surgical and non-surgical measures to mitigate this complication and to improve overall cochlear implant outcomes.

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.

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 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.

Language Outcomes in Cochlear Implanted Children with White Matter Disturbances

Introduction:

The present study reviews our experience with children with white matter disturbances and the benefits they get from rehabilitation post cochlear implantation.

Materials and Methods:

It is a retrospective cohort study of 7 cochlear implanted children with white matter disturbances. Preoperatively all the subjects had undergone a complete Audiological test battery for confirmation of hearing thresholds. Post assessment, a digital hearing aid trial was followed by three months’ therapy. Unilateral cochlear implant surgery and monitored auditory-verbal therapy sessions were the next line of treatment for at least one year. The therapist regularly monitored hearing and communication outcomes on an Auditory verbal ongoing scale, revised CAP, MAIS, word, and sentence discrimination scores.

Results:

The age range of Implantation was between 48 to 60 months. 5 out of 7 participants showed remarkable improvement with regular therapy. Their Meaningful Auditory Integration Scale (MAIS) scores were greater than 35 indicating good auditory integration and Categories of Auditory Performance (CAP) revealed scores of even 9 and higher indicating good telephone conversation. Speech Intelligibility Rating (SIR) showed a rating of 4 meaning thereby that an unfamiliar Listener could understand Speech without additional cues. However, all of them reported difficulty perceiving speech in noisy environments. Two cochlear implantees needed speech reading cues in conjunction with the audition.

Conclusion:

Our experience with cochlear Implantation in children with white matter abnormalities has been positive and satisfactory. The presence of white matter abnormalities on MRI should not be a contraindication for Implantation. Successful outcomes can be expected with regular and dedicated auditory-verbal therapy sessions.

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.

Peristapedial bulb: an indicator of spontaneous CSF leak in cochlear candidates with Mondini dysplasia

BACKGROUND

Mondini dysplasia with spontaneous cerebrospinal fluid (CSF) leak is rare in cochlear implantation (CI) candidates but lethal. Detailed evaluation and surgical intervention are needed for these patients.

AIM/OBJECTIVE

To report our findings of the peristapedial bulb in computer tomography (CT) as diagnostic evidence of spontaneous CSF leak and discuss its clinical value to direct the surgical plan for patients with profound sensorineural hearing loss (SNHL) and meningitis.

MATERIAL AND METHODS

A retrospective review was conducted, including patients' demographic features, radiographic examination, operation records, auditory/speech evaluation. The patients presented with a peristapedial bulb were included.

RESULTS

In 2775 CI recipients, 7 out of 219 (3.2%) patients with Mondini anomaly had detectable peristapedial bulbs in HRCT, among whom 6 patients have a history of meningitis. Surgical exploration verified the radiographic findings in 6 out of 7 patients. All patients received CI and vestibular obliteration. Control of meningitis was acceptable. The threshold of hearing significantly decreased from 74.1 dB ± 6.9 dB to 37.1 ± 4.8 dB after CI and the word recognition score elevated from 21.4 ± 14.9% to 78.6 ± 9.3%.

CONCLUSIONS AND SIGNIFICANCE

Peristapedial bulb is an indicator of spontaneous CSF leak in patients with profound SHNL and Mondini anomaly. Patients will benefit from CI and surgical intervention.

Abnormal cochleovestibular anatomy and imaging: Lack of consistency across quality of images, sequences obtained, and official reports

OBJECTIVES

There are significant variations across centers on how to acquire and interpret imaging of children with congenital sensorineural hearing loss and cochleovestibular abnormalities. This study assesses the quality of imaging, sequences included, and accuracy of official radiology reports, to determine if these children are being assessed appropriately.

METHODS

This study is retrospective review of CTs and MRIs from 40 pediatric patients diagnosed with profound sensorineural hearing loss and cochleovestibular structure/nerve abnormalities presenting to a tertiary referral academic center. Images were reviewed by two experienced neuroradiologists and a neurotologist. Findings were compared to official reports, when available.

RESULTS

Twelve (30%) patients had an MRI only, while 28 (70%) had both an MRI and a CT. There were 3 (10.7%) CTs and 7 (17.5%) MRIs noted to be of poor quality. Children received an average of 6.8 (±2.7) CT acquisitions and 10.9 (±5.7) MRI acquisitions. There was non-concordance between the official report and expert review for 27 (71.1%) ears on CT and 27 (56.3%) ears on MRI.

CONCLUSIONS

These data demonstrate high variability in protocols and quality of medical imaging of children with sensorineural hearing loss. Interpretation of images is highly discordant between official reports and tertiary review. Given these results, we recommend that these children be imaged and evaluated at centers with neuroradiologists who are experienced in interpreting congenital abnormalities of the cochleovestibular system.

Assessing the Benefit-Risk Profile for Pediatric Implantable Auditory Prostheses

BACKGROUND/AIMS

Children with congenital cochleovestibular abnormalities associated with profound hearing loss have few treatment options if cochlear implantation does not yield benefit. An alternative is the auditory brainstem implant (ABI). Regulatory authority device approvals currently include a structured benefit-risk assessment. Such an assessment, for regulatory purposes or to guide clinical decision making, has not been published, to our knowledge, for the ABI and may lead to the design of a research program that incorporates regulatory authority, family, and professional input.

METHODS

Much structured benefit-risk research has been conducted in the context of drug trials; here we apply this approach to device studies. A qualitative framework organized benefit (speech recognition, parent self-report measures) and risk (surgery- and device-related) information to guide the selection of candidates thought to have potential benefit from ABI.

RESULTS

Children with cochleovestibular anatomical abnormalities are challenging for appropriate assessment of candidacy for a cochlear implant or an ABI. While the research is still preliminary, children with an ABI appear to slowly obtain benefit over time. A team of professionals, including audiological, occupational, and educational therapy, affords maximum opportunity for benefit.

CONCLUSIONS

Pediatric patients who have abnormal anatomy and are candidates for an implantable auditory prosthetic require an individualized, multisystems review. The qualitative benefit-risk assessment used here to characterize the condition, the medical need, potential benefits, risks, and risk management strategies has revealed the complex factors involved. After implantation, continued team support for the family during extensive postimplant therapy is needed to develop maximum auditory skill benefit.

Favorable Long-Term Functional Outcomes and Safety of Auditory Brainstem Implants in Nontumor Patients

BACKGROUND

Auditory brainstem implants (ABIs) were designed to restore hearing in deaf patients with auditory tumors or those unable to receive cochlear implants. Although ABIs may help some patients, their long-term outcomes have been rarely studied.

OBJECTIVE

To assess the long-term benefits and safety of ABIs in nontumor patients with sensorineural hearing loss (SNHL).

METHODS

We retrospectively reviewed the histories of 15 deaf patients (8 females, 7 males; mean age, 15.5 yr; range, 1-56 yr) who received ABIs for treatment of SNHL at our hospital from July 2008 to November 2015. These included 11 children with narrow internal auditory canals and 4 deaf adults with severe cochlear ossification. In each patient, a 12-channel ABI electrode was placed in the cochlear nucleus complex via a retrosigmoid approach. Auditory performance was evaluated using the Categories of Auditory Performance (CAP) index and sound detection and word identification tests.

RESULTS

One year after ABI placement, 13 of 15 patients showed adequate or significantly improved auditory function based on the CAP scores at the last follow-up. Generally, adult patients tended to show better CAP scores (3.50) than pediatric patients (2.15), but the difference was not significant (P = .058). Postoperative complications included electrode migration, cerebrospinal fluid leakage, nonauditory stimulation, and minor seizures without severe sequelae or mortality.

CONCLUSION

ABIs show favorable functional outcomes and long-term safety in nontumor deaf patients with limited treatment options. Collectively, our data indicate that ABIs represent an important treatment option for SNHL.

Prevalence of inner ear anomalies among cochlear implant candidates

OBJECTIVES

To determine the prevalence of inner ear anomalies and the frequency of different anomaly types among cochlear implant recipients.

METHODS

This study included a retrospective chart review of all patients who received cochlear implants between January 2009 and January 2013 in King Abdulaziz University Hospital cochlear implant program in Riyadh, Saudi Arabia. All subjects underwent thin-cut CT of the temporal bone and MRI. The collected data included age, gender, and CT and MRI findings regarding temporal bone anomalies. Patients with any identified congenital inner ear anomalies were included in the study. 

RESULTS

In total, 316 patients' cases were reviewed. Inner ear malformations were identified in 24 patients, which represented a prevalence of 7.5%. Among these 24 patients, 8 (33.3%) presented with a large vestibular aqueduct (LVA), 8 (33.3%) semicircular canal (SCC) dysplasia, 7 (29.1%) classical Mondini deformity, and one (4.1%) cochlear hypoplasia.

CONCLUSION

The prevalence of inner ear anomalies among cochlear implant recipients was 7.5%. This result is consistent with findings worldwide. The most common anomalies were LVA and SCC hypoplasia; by contrast, in other regions, the most common anomaly is either the Mondini deformity, or LVA.

Cochlear Implantation in Inner Ear Malformations: Systematic Review of Speech Perception Outcomes and Intraoperative Findings

Objective

(1) To analyze reported speech perception outcomes in patients with inner ear malformations who undergo cochlear implantation, (2) to review the surgical complications and findings, and (3) to compare the 2 classification systems of Jackler and Sennaroglu.

Data Sources

PubMed, Scopus (including Embase), Medline, and CINAHL Plus.

Review Methods

Fifty-nine articles were included that contained speech perception and/or intraoperative data. Cases were differentiated depending on whether the Jackler or Sennaroglu malformation classification was used. A meta-analysis of proportions examined incidences of complete insertion, gusher, and facial nerve aberrancy. For speech perception data, weighted means and standard deviations were calculated for all malformations for short-, medium-, and long-term follow-up. Speech tests were grouped into 3 categories—closed-set words, open-set words, and open-set sentences—and then compared through a comparison-of-means t test.

Results

Complete insertion was seen in 81.8% of all inner ear malformations (95% CI: 72.6-89.5); gusher was reported in 39.1% of cases (95% CI: 30.3-48.2); and facial nerve anomalies were encountered in 34.4% (95% CI: 20.1-50.3). Significant improvements in average performance were seen for closed- and open-set tests across all malformation types at 12 months postoperatively.

Conclusions

Cochlear implantation outcomes are favorable for those with inner ear malformations from a surgical and speech outcome standpoint. Accurate classification of anatomic malformations, as well as standardization of postimplantation speech outcomes, is necessary to improve understanding of the impact of implantation in this difficult patient population.

Predictors of pediatric cochlear implantation outcomes in South Africa

OBJECTIVE

To identify and describe predictors of pediatric cochlear implantation outcomes in a South African population.

METHODS

A retrospective study of 301 pediatric cochlear implant (CI) recipients from five CI programs was conducted and cross-sectional outcome data were added at the time of data collection. Twenty potential prognostic factors were identified from the retrospective dataset, including demographical, CI, risk and family factors. Multiple regression analyses were performed to identify predictor variables that influence outcomes in terms of auditory performance (CAP scores), speech production (SIR scores), communication mode and educational placement.

RESULTS

Although implanted children within this sample did not have equal opportunity to access a second implant, bilateral implantation was strongly predictive of better auditory performance and speech production scores, an oral mode of communication and mainstream education. NICU admittance/prematurity were associated with poorer auditory performance and speech production scores, together with a higher probability for non-oral communication and non-mainstream education. The presence of one or more additional developmental condition was predictive of poorer outcomes in terms of speech production and educational placement, while a delay between diagnosis and implantation of more than one year was also related to non-mainstream education. Ethnicities other than Caucasian were predictive of poorer auditory performance scores and a lower probability for mainstream education.

CONCLUSION

An extensive range of prognostic indicators were identified for pediatric CI outcomes in South Africa. These predictive factors of better and poorer outcomes should guide pediatric CI services to promote optimal outcomes and assist professionals in providing evidence-based informational counseling.

A semi-supervised Support Vector Machine model for predicting the language outcomes following cochlear implantation based on pre-implant brain fMRI imaging

INTRODUCTION

We developed a machine learning model to predict whether or not a cochlear implant (CI) candidate will develop effective language skills within 2 years after the CI surgery by using the pre-implant brain fMRI data from the candidate.

METHODS

The language performance was measured 2 years after the CI surgery by the Clinical Evaluation of Language Fundamentals-Preschool, Second Edition (CELF-P2). Based on the CELF-P2 scores, the CI recipients were designated as either effective or ineffective CI users. For feature extraction from the fMRI data, we constructed contrast maps using the general linear model, and then utilized the Bag-of-Words (BoW) approach that we previously published to convert the contrast maps into feature vectors. We trained both supervised models and semi-supervised models to classify CI users as effective or ineffective.

RESULTS

Compared with the conventional feature extraction approach, which used each single voxel as a feature, our BoW approach gave rise to much better performance for the classification of effective versus ineffective CI users. The semi-supervised model with the feature set extracted by the BoW approach from the contrast of speech versus silence achieved a leave-one-out cross-validation AUC as high as 0.97. Recursive feature elimination unexpectedly revealed that two features were sufficient to provide highly accurate classification of effective versus ineffective CI users based on our current dataset.

CONCLUSION

We have validated the hypothesis that pre-implant cortical activation patterns revealed by fMRI during infancy correlate with language performance 2 years after cochlear implantation. The two brain regions highlighted by our classifier are potential biomarkers for the prediction of CI outcomes. Our study also demonstrated the superiority of the semi-supervised model over the supervised model. It is always worthwhile to try a semi-supervised model when unlabeled data are available.

Development of auditory skills after cochlear implantation in children with inner ear malformations

CONCLUSIONS

CI improves hearing thresholds and auditory skills in children with most types of inner ear malformations. However, the development of sound detection skills is not as good as it is in children without inner ear malformations.

OBJECTIVES

To investigate the influence of inner ear malformations on development of auditory skills after cochlear implantation (CI).

METHODS

Records of 20 children with inner ear malformations who underwent cochlear implantation before 4 years of age and followed up for more than 2 years were retrospectively reviewed. Hearing thresholds, the Meaningful Auditory Integration Scale (MAIS), and Meaningful Use of Speech Scale (MUSS) scores before and after CI were analyzed and compared with 20 age-matched deaf children who underwent CI.

RESULTS

The children with inner ear malformations showed significant improvements in hearing thresholds and the MAIS and MUSS scores 1 year after CI (p < 0.01). However, their development of the MAIS scores was significantly delayed compared to children without inner ear malformations (p < 0.05), while there was no significant difference in development of the MUSS scores between them. Significant improvements in hearing thresholds and the MAIS and MUSS scores were observed in cochlear hypoplasia and incomplete partition (p < 0.05).

Cochlear Implant Outcomes and Genetic Mutations in Children with Ear and Brain Anomalies

Background. Specific clinical conditions could compromise cochlear implantation outcomes and drastically reduce the chance of an acceptable development of perceptual and linguistic capabilities. These conditions should certainly include the presence of inner ear malformations or brain abnormalities. The aims of this work were to study the diagnostic value of high resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in children with sensorineural hearing loss who were candidates for cochlear implants and to analyse the anatomic abnormalities of the ear and brain in patients who underwent cochlear implantation. We also analysed the effects of ear malformations and brain anomalies on the CI outcomes, speculating on their potential role in the management of language developmental disorders. Methods. The present study is a retrospective observational review of cochlear implant outcomes among hearing-impaired children who presented ear and/or brain anomalies at neuroimaging investigations with MRI and HRCT. Furthermore, genetic results from molecular genetic investigations (GJB2/GJB6 and, additionally, in selected cases, SLC26A4 or mitochondrial-DNA mutations) on this study group were herein described. Longitudinal and cross-sectional analysis was conducted using statistical tests. Results. Between January 1, 1996 and April 1, 2012, at the ENT-Audiology Department of the University Hospital of Ferrara, 620 cochlear implantations were performed. There were 426 implanted children at the time of the present study (who were <18 years). Among these, 143 patients (64 females and 79 males) presented ear and/or brain anomalies/lesions/malformations at neuroimaging investigations with MRI and HRCT. The age of the main study group (143 implanted children) ranged from 9 months and 16 years (average = 4.4; median = 3.0). Conclusions. Good outcomes with cochlear implants are possible in patients who present with inner ear or brain abnormalities, even if central nervous system anomalies represent a negative prognostic factor that is made worse by the concomitant presence of cochlear malformations. Common cavity and stenosis of the internal auditory canal (less than 2 mm) are negative prognostic factors even if brain lesions are absent.

Role of HRCT and MRI of the Temporal Bone in Predicting and Grading the Degree of Difficulty of Cochlear Implant Surgery

This study proposes a grading system based on a 10-point scoring chart of high resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) imaging findings in patients being assessed preoperatively for cochlear implantation. This system helps in objectively assessing the degree of difficulty of the surgical procedure and alerts the surgeons to any potential intraoperative complications. This is a prospective study carried out at a tertiary referral center where 55 patients with bilateral profound sensorineural hearing loss were evaluated by HRCT and MRI and subsequently underwent cochlear implantation. HRCT examinations were performed on a 64 slice multidetector CT scanner. MRI examinations were performed on a 3.0 Tesla MRI scanner. A 10-point scoring chart was devised based on specific imaging findings and all patients were assigned potential difficulty scores (PDS) based on HRCT and MRI findings. Surgical times were documented in each case and each imaging point on the scoring chart was correlated with the surgical times. Eight out of theó ten points in the scoring chart proved to be statistically significant in predicting the degree of difficulty of the surgical procedure. After grading the pre-operative imaging examinations based on the 10-point scoring chart we concluded that patients who have PDS between 0 and 3 (Grade 1) have uneventful and uncomplicated surgery with the lowest intraoperative times. Patients with PDS between 4 and 7 alert the surgeon to moderate surgical difficulty and longer intraoperative times. PDS of 8 and above indicate prolonged and difficult surgery.

Effectiveness of cochlear implant in inner ear bone malformations with anterior labyrinth involvement

OBJECTIVE

To study electrical stimulation, auditory functionality, and language development in patients with inner ear malformations involving the anterior labyrinth who underwent cochlear implantation.

STUDY DESIGN

Retrospective case review.

SETTING

Reference hospital for cochlear implantation.

PATIENTS

Review of 14 cases of severe hearing loss with major (common cavity deformity and cochlear hypoplasia) or minor (e.g., incomplete partition and basal turn aplasia) malformations.

INTERVENTIONS

After cochlear implantation, data were gathered on the threshold (THR) and maximum comfort level (MCL) of the electrical stimulation and the number of functioning electrodes. Auditory responses to speech (EARS protocol) subtests were used to evaluate auditory functionality and language acquisition at 6, 12, and 24 months post-implantation. Tests used were: LIP profile, MTP (3, 6 and 12 words), OLD (open set test) and CLD (close set test). Results were compared with findings in a control group of 28 cochlear implantation patients without these malformations and with congenital hearing loss.

RESULTS

The mean THR was 11.02μC in patients with malformations versus 3.5μC in those without, a significant difference. The THR also significantly differed between groups with major and minor malformations. Fewer functioning electrodes were used in patients with malformations. Auditory functionality scores were best in controls than in patients with malformations, who scored ≤50%, finding the lowest scores in those with major malformations.

CONCLUSION

Patients with inner ear malformations undergoing cochlear implantation require greater stimuli to obtain an auditory response and have worse auditory functionality outcomes; these differences are greater in those with major versus minor malformations Nevertheless, cochlear implantation appears to be beneficial for all patients with these malformations to a greater or lesser extent.

The development of auditory skills in young children with Mondini dysplasia after cochlear implantation

The aim of this study is to survey and compare the development of auditory skills in young children with Mondini dysplasia and profoundly-deaf young children with radiologically normal inner ears over a period of 3 years after cochlear implantation. A total of 545 young children (age 7 to 36 months) with prelingual, severe to profound hearing loss participated in this study. All children received cochlear implantation. Based on whether or not there was a Mondini dysplasia as diagnosed with CT scanning, the subjects were divided into 2 groups: (A) 514 young children with radiologically normal inner ears and (B) 31 young children with Mondini dysplasia. The Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) was used to assess the children's auditory skills that include vocalization changes, spontaneous alerting to sounds in everyday living environments, and the ability to derive meaning from sounds. The assessment was performed prior to surgery and at 1, 3, 6, 9, 12, 24, and 36 months after implant device switch-on. The mean scores for overall auditory skills were not significantly different between groups A and B at pre-surgery, 1, 12, 24, and 36 months post-surgery, but were significantly different at 3, 6, and 9 months post-surgery. The mean scores for all auditory skills in children with Mondini dysplasia showed significant improvement over time. The mean scores for the three subcategories of auditory skills in children with Mondini dysplasia also showed significant differences at pre-surgery, 1, 3, 6, and 9 months, however, there were no significant differences at 12, 24, and 36 months. Overall, the auditory skills of young children with Mondini dysplasia developed rapidly after cochlear implantation, in a similar manner to that of young children with radiologically normal inner ears. Cochlear implantation is an effective intervention for young children with Mondini dysplasia.

MAP optimization as a predictor of cochlear implant outcomes in children with narrow internal auditory canal

OBJECTIVES

The purposes of this study were to investigate the auditory performance and MAP characteristics of implanted children with narrow internal auditory canal (IAC), and to examine the clinical usefulness of MAP optimization as a predictor of their cochlear implant (CI) outcomes by analyzing their auditory performance and habilitation methods in relation to MAP optimization.

METHODS

Eight children with narrow IAC who had used a CI over 3 years were included. We retrospectively examined their auditory performance and MAPs. Auditory performance was measured by the Categories of Auditory Performance (CAP) and monosyllabic word tests before and after implantation. The relationship between auditory performance and MAP parameters was explored, and their habilitation methods were analyzed.

RESULTS

Mean CAP scores improved from .25 preoperatively to 3.5 3 years postoperatively. Mean scores for monosyllabic word tests improved from 0% preoperatively to 27.8% 3 years postoperatively. The children used MAPs with a wider pulse width than the default setting. Four children using optimal MAPs achieved open-set speech perception, so were trained in the oral approach. The other four using suboptimal MAPs because of non-auditory stimulation achieved no open-set speech perception, so were trained in the total communication approach.

CONCLUSIONS

MAP optimization had a predictable value in determining the postoperative performance of children with narrow IAC who received a CI. The most suitable habilitation method can be determined early after implantation by identifying the presence of MAP optimization.

Cochlear implantation in children with cochlear aplasia

CONCLUSION

Children with cochlear aplasia can achieve favorable speech perception abilities from cochlear implantation (CI) by inserting an electrode array into the vestibule if an audiological response is reliably demonstrated before surgery by behavioral audiometry and objective measures.

OBJECTIVES

The purpose of this study was to evaluate the surgical outcome of CI in children with cochlear aplasia.

METHODS

The medical records of 454 children who underwent CI at the Dong-A University Hospital between January 1994 and September 2011 were reviewed. The prevalence of cochlear aplasia and the preoperative evaluations, operative findings, and postoperative speech perception abilities of implanted children with cochlear aplasia were evaluated.

RESULTS

The implanted children with cochlear aplasia accounted for 2% of those with inner ear malformations and 0.4% of all pediatric cochlear implantees. They showed audiological responses in preoperative electrophysiologic tests, and the eighth nerve was present in magnetic resonance imaging. The electrode array was inserted into the vestibule through an oval window after removing the stapes or through a transmastoid labyrinthotomy site. Electrical compound action potential and electrical auditory brainstem response tests showed clear neural responses after implantation. The hearing thresholds of the implanted ear improved to 25 dB HL and the children achieved significant open set speech perception abilities.

Speech perception and production in children with inner ear malformations after cochlear implantation

OBJECTIVE

The aim of this study was to assess the speech perception and speech intelligibility outcome after cochlear implantation in children with malformed inner ear and to compare them with a group of congenitally deaf children implantees without inner ear malformation.

METHODS

Six deaf children (five boys and one girl) with inner ear malformations who were implanted and followed in our clinic were included. These children were matched with six implanted children with normal cochlea for age at implantation and duration of cochlear implant use. All subjects were tested with the internationally used battery tests of listening progress profile (LiP), capacity of auditory performance (CAP), and speech intelligibility rating (SIR). A closed and open set word perception test adapted to the Modern Greek language was also used. In the dysplastic group, two children suffered from CHARGE syndrome, another two from mental retardation, and two children grew up in bilingual homes.

RESULTS

At least two years after switch-on, the dysplastic group scored mean LiP 62%, CAP 3.8, SIR 2.1, closed-set 61%, and open-set 49%. The children without inner ear dysplasia achieved significantly better scores, except for CAP which this difference was marginally statistically significant (p=0.009 for LiP, p=0.080 for CAP, p=0.041 for SIR, p=0.011 for closed-set, and p=0.006 for open-set tests).

CONCLUSION

All of the implanted children with malformed inner ear showed benefit of auditory perception and speech production. However, the children with inner ear malformation performed less well compared with the children without inner ear dysplasia. This was possibly due to the high proportion of disabilities detected in the dysplastic group, such as CHARGE syndrome and mental retardation. Bilingualism could also be considered as a factor which possibly affects the outcome of implanted children. Therefore, children with malformed inner ear should be preoperatively evaluated for cognitive and developmental delay. In this case, counseling for the parents is mandatory in order to explain the possible impact of the diagnosed disabilities on performance and habilitation.

Pediatric cochlear implantation: candidacy evaluation, medical and surgical considerations, and expanding criteria

Since the first cochlear implant approved by the US Food and Drug Administration in the early 1980s, great advances have occurred in cochlear implant technology. With these advances, patient selection, preoperative evaluation, and rehabilitation consideration continue to evolve. This article describes the current practice in pediatric candidacy evaluation, reviews the medical and surgical considerations in pediatric cochlear implantation, and explores the expanding criteria for cochlear implantation within the pediatric population.

Early surgical results of auditory brainstem implantation in nontumor patients

OBJECTIVES/HYPOTHESIS

An auditory brainstem implant (ABI) that stimulates the cochlear nucleus in the brainstem was initially designed for patients with neurofibromatosis type-2. Recently, promising surgical outcomes after ABI have been reported in nontumor patients with sensorineural hearing loss including those with cochlear nerve aplasia or ossified cochlea. We herein describe the surgical results and auditory outcomes of ABI in nontumor patients.

STUDY DESIGN

Retrospective case series at a tertiary hospital.

METHODS

Eleven deaf patients who received ABI from 2008 to 2010 were included in this study. The first group included eight patients with narrow internal auditory canals (IACs) and the second group consisted of three postlingually deaf adults with cochlear ossification. Pulsar CI100 ABI (Med-El Co., Innsbruck, Austria) was implanted via the suboccipital approach.

RESULTS

All eight patients with narrow IACs clearly demonstrated behavioral responses following initial stimulation using an ABI. The category of auditory performance (CAP) scores were progressively improved to reach auditory performances of CAP 4 in three patients, CAP 3 in two patients, CAP 2 in two patients, and CAP 1 in one patient. The three patients with ossified cochlea also reported auditory sensations when the ABI was activated. Two of them showed an auditory performance of CAP 4 or 5, but the third patient could not use the device due to nonauditory stimulation.

CONCLUSIONS

Based on our experience, ideal nontumor candidates for ABI include congenitally deaf children who experienced failure after cochlear implantation owing to cochlear nerve deficiency and postlingually deaf adults with severe cochlear ossification.

The cochleovestibular nerve identified during auditory brainstem implantation in patients with narrow internal auditory canals: can preoperative evaluation predict cochleovestibular nerve deficiency?

OBJECTIVES/HYPOTHESIS

To analyze the value of preoperative diagnostic tools in predicting the status of the cochleovestibular nerve (CVN) in patients with narrow internal auditory canals (IAC).

STUDY DESIGN

Retrospective case series at a tertiary hospital.

METHODS

Eight profoundly deaf patients with narrow IACs who received auditory brainstem implantation were included in this study. The results of preoperative imaging, electrophysiologic, and auditory tests were correlated with the CVN status identified during auditory brainstem implantation.

RESULTS

Temporal bone computed tomography (CT) findings, including the patency of the bony cochlear nerve canal and the diameter of the IAC, were limited in accurately reflecting the status of the CVN. Magnetic resonance imaging (MRI) and preoperative auditory responses to either pure tone or environmental sounds were more accurate markers for detecting the presence of a CVN than CT; however, there were limitations in cases with a very thin CVN or combined severe mental retardation. Absence of promontory or intracochlear electrically evoked auditory brainstem responses were not always indicative of an absent CVN.

CONCLUSIONS

Visualization on MRI and detection of auditory responses suggested the presence of a CVN in patients with narrow IACs; however, the possibility of the presence of a CVN should be considered even when there is no clear evidence of a CVN on preoperative evaluations. Therefore, physicians should be prudent when determining candidacy for cochlear implantation or auditory brainstem implantation in patients with narrow IACs.

The development of auditory skills in infants with isolated Large Vestibular Aqueduct Syndrome after cochlear implantation

OBJECTIVE

The purpose of this study was to investigate the auditory performance of infants with isolated Large Vestibular Aqueduct Syndrome (LVAS) after cochlear implantation, compare their performance with those of infants with a normal inner ear, and establish a database of auditory development.

METHOD

435 infants with congenital severe to profound hearing loss participated in this study. 62 infants in group A were diagnosed with isolated LVAS. 373 infants in group B had a normal inner ear. Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) was used to evaluate the development of auditory skills.

RESULTS

The mean scores for auditory ability showed no significant difference between groups A and B. The mean scores for the three different auditory skills increased significantly over time. The differences were statistically significant in mean scores among the three different auditory skills for group B.

CONCLUSION

Auditory skills of infants with isolated LVAS developed rapidly after cochlear implantation, in a similar manner to those of infants with a normal inner ear. Cochlear implantation is an effective interventional approach and an established therapeutic option for infants with isolated LVAS.

Complications in auditory brainstem implant surgery in adults and children

OBJECTIVE

Surgery for hearing restoration with auditory brainstem implantation (ABI) in patients with neurofibromatosis type 2 (NF2) is considered safe, as no increase in postoperative complications related to surgery or device implantation has been observed. Over the last 10 years, we have extended the use of ABI to nontumor (NT) adults and children with cochlear or cochlear nerve malfunctions who would not or did not benefit from a cochlear implant (CI). This article examines the complications encountered in ABI surgery in all patient groups.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

: One hundred fourteen ABI operations were performed in Verona (Italy) from 1997 to 2008 in 83 adults and 31 children. Thirty-six had NF2 (34 adults and 2 children), and 78 (49 adults and 29 children) had NT cochlear and cochlear nerve disorders.

INTERVENTION

A retrosigmoid-transmeatal approach was used in the NF2 cases, and a simple retrosigmoid approach was used in the NT patients.

MAIN OUTCOME MEASURES

Surgical complications are tabulated according to standard reporting categories and are presented separately and analyzed statistically for NF2, NT adults, and NT children. Complication rates are compared with those of CI and microvascular decompression surgery.

RESULTS

ABI surgery has a very low major complication rate, particularly in non-NF2 patients. Minor complications were easily controlled with complete resolution in all cases. Although the potential complications of intradural ABI implantation are more severe than those of a transmastoid approach for CIs, the actual observed complication rates in ABI candidates without NF2 tumors are comparable to those of CI surgery in both adults and children.

CONCLUSION

This study demonstrates that the ABI is a safe procedure when performed by an experienced surgical and rehabilitation team, and its benefits can be extended to a larger population of deaf patients.

The effects of age at cochlear implantation and hearing aid trial on auditory performance of Chinese infants

CONCLUSION

Most of the infants demonstrated rapid improvement in the three different auditory skills within the first year after switch-on. Infants undergoing hearing aid trial and habilitation demonstrated a significant positive effect on the development of auditory skills in comparison with infants without trial and habilitation.

OBJECTIVE

This paper aims to evaluate the auditory performance of infants of different age at cochlear implantation, emphasize the importance of the hearing aid trial and habilitation before implant, and provide baseline data of auditory development.

METHODS

In all, 259 infants with prelingually profound hearing loss participated in this study. The Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) was used to assess auditory skills in infants at different intervals.

RESULTS

The mean scores for the auditory skills improved significantly over time. The mean scores of three skills for each group at each interval were significantly different. The mean scores of the auditory skills were significantly superior for infants undergoing hearing aid trial and habilitation in comparison with those of infants without hearing aid trial and habilitation.