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.

Association of Ear Anomalies and Hearing Loss Among Children With 22q11.2 Deletion Syndrome

OBJECTIVE

To identify inner and middle ear anomalies in children with 22q11.2 deletion syndrome (22q11DS) and determine associations with hearing thresholds.

STUDY DESIGN

Retrospective study.

SETTING

Two tertiary care academic centers.

METHODS

Children presenting with 22q11DS between 2010 and 2020 were included. Temporal bone imaging with computed tomography or magnetic resonance imaging was reviewed by 2 neuroradiologists.

RESULTS

Twenty-two patients (12 female, 10 male) were identified. Forty-four ears were evaluated on imaging. There were 15 (34%) ears with abnormal semicircular canals, 14 (32%) with abnormal vestibules, 8 (18%) with abnormal ossicles, 6 (14%) with enlarged vestibular aqueducts, 4 (9.1%) with abnormal facial nerve canals, and 4 (9.1%) with cochlear anomalies. There were 25 ears with imaging and audiometric data. The median pure tone average (PTA) for ears with any structural abnormality was 41.0 dB, as compared with 28.5 dB for ears without any structural abnormality (P = .21). Of 23 ears with normal imaging, 6 (26%) had hearing loss in comparison with 13 (62%) of 21 ears with abnormalities (P = .02). Total number of anomalies per ear was positively correlated with PTA (Pearson correlation coefficient, R = 0.479, P = .01). PTA was significantly higher in patients with facial nerve canal anomalies (P = .002), vestibular aqueduct anomalies (P = .05), and vestibule anomalies (P = .02).

CONCLUSIONS

Semicircular canal, ossicular, vestibular aqueduct, and vestibular anomalies were detected in children with 22q11DS, especially in the setting of hearing loss. Careful evaluation of anatomic anomalies is needed prior to surgical intervention in these patients.

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.

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.

The Effects of GJB2 or SLC26A4 Gene Mutations on Neural Response of the Electrically Stimulated Auditory Nerve in Children

OBJECTIVES

This study aimed to (1) investigate the effect of GJB2 and SLC26A4 gene mutations on auditory nerve function in pediatric cochlear implant users and (2) compare their results with those measured in implanted children with idiopathic hearing loss.

DESIGN

Participants included 20 children with biallelic GJB2 mutations, 16 children with biallelic SLC26A4 mutations, and 19 children with idiopathic hearing loss. All subjects except for two in the SLC26A4 group had concurrent Mondini malformation and enlarged vestibular aqueduct. All subjects used Cochlear Nucleus devices in their test ears. For each subject, electrophysiological measures of the electrically evoked compound action potential (eCAP) were recorded using both anodic- and cathodic-leading biphasic pulses. Dependent variables (DVs) of interest included slope of eCAP input/output (I/O) function, the eCAP threshold, and eCAP amplitude measured at the maximum comfortable level (C level) of the anodic-leading stimulus (i.e., the anodic C level). Slopes of eCAP I/O functions were estimated using statistical modeling with a linear regression function. These DVs were measured at three electrode locations across the electrode array. Generalized linear mixed effect models were used to evaluate the effects of study group, stimulus polarity, and electrode location on each DV.

RESULTS

Steeper slopes of eCAP I/O function, lower eCAP thresholds, and larger eCAP amplitude at the anodic C level were measured for the anodic-leading stimulus compared with the cathodic-leading stimulus in all subject groups. Children with GJB2 mutations showed steeper slopes of eCAP I/O function and larger eCAP amplitudes at the anodic C level than children with SLC26A4 mutations and children with idiopathic hearing loss for both the anodic- and cathodic-leading stimuli. In addition, children with GJB2 mutations showed a smaller increase in eCAP amplitude when the stimulus changed from the cathodic-leading pulse to the anodic-leading pulse (i.e., smaller polarity effect) than children with idiopathic hearing loss. There was no statistically significant difference in slope of eCAP I/O function, eCAP amplitude at the anodic C level, or the size of polarity effect on all three DVs between children with SLC26A4 mutations and children with idiopathic hearing loss. These results suggested that better auditory nerve function was associated with GJB2 but not with SLC26A4 mutations when compared with idiopathic hearing loss. In addition, significant effects of electrode location were observed for slope of eCAP I/O function and the eCAP threshold.

CONCLUSIONS

GJB2 and SLC26A4 gene mutations did not alter polarity sensitivity of auditory nerve fibers to electrical stimulation. The anodic-leading stimulus was generally more effective in activating auditory nerve fibers than the cathodic-leading stimulus, despite the presence of GJB2 or SLC26A4 mutations. Patients with GJB2 mutations appeared to have better functional status of the auditory nerve than patients with SLC26A4 mutations who had concurrent Mondini malformation and enlarged vestibular aqueduct and patients with idiopathic hearing loss.

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.

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 Novel Surgical Technique for the Management of Cerebrospinal Fluid Gusher Encountered During Cochlear Implantation

: Cerebrospinal fluid (CSF) gusher encountered during cochlear implantation are most commonly encountered in the setting of an inner ear abnormality. Repair of the gusher is essential to prevent CSF egress postoperatively and to decrease the risk of meningitis. Various methods to repair a CSF gusher have been described, including tight packing of the cochleostomy with fascia, lumbar drainage, and Eustachian tube packing with ear canal overclosure. We describe a novel and simple technique using a fascia ring placed around the cochlear implantation electrode (Cochlear Corporation, CI522) as a means to treat CSF gusher. The fascia is slid down the electrode after insertion, allowing circumferential coverage of the defect. The following video will provide an overview of patients at risk for CSF gusher and demonstrate the technique described above.SDC video link: http://links.lww.com/MAO/B52.

Effects of Age at Auditory Brainstem Implantation: Impact on Auditory Perception, Language Development, Speech Intelligibility

OBJECTIVE

To study the effect of age at auditory brainstem implant (ABI) surgery on auditory perception, language, and speech intelligibility.

STUDY DESIGN

Retrospective single cohort design.

SETTING

Tertiary referral center.

PATIENTS

In this study, 30 pediatric ABI users with no significant developmental issues were included. Participants were divided into two groups, according to age at surgery (Early Group: < 3 yr old [n = 15], Late Group: ≥ 3 yr old [n = 15]). Groups were matched by duration of ABI use and participants were evaluated after 5 years (±1 yr) experience with their device. The mean age at ABI surgery was 22.27 (ranged ± 6.5) months in the early group, 45.53 (ranged ± 7.9) months in the late group.

INTERVENTION(S)

Retrosigmoid craniotomy and ABI placement.

MAIN OUTCOME MEASURE(S)

Auditory perception skills were evaluated using the Meaningful Auditory Integration Scale and Categories of Auditory Performance from the Children's Auditory Perception Test Battery. We used a closed-set pattern perception subtest, a closed-set word identification subtest, and an open-set sentence recognition subtest. Language performance was assessed with the Test of Early Language Development and Speech Intelligibility Rating, which was administered in a quiet room.

RESULTS

In this study, the results demonstrated that the Early Group's auditory perception performance was better than the Late Group after 5 years of ABI use, when children had no additional needs (U = 12, p < 0.001). Speech intelligibility was the most challenging skill to develop, in both groups. Due to multiple regression analysis, we found that auditory perception categories can be estimated with speech intelligibility scores, pattern perception scores, receptive language scores, and age at ABI surgery variables in ABI users with no additional handicaps.

CONCLUSIONS

ABI is a viable option to provide auditory sensations for children with cochlear anomalies. ABI surgery under age 3 is associated with improved auditory perception and language development compared with older users.

Evolving Criteria for Adult and Pediatric Cochlear Implantation

The indications for cochlear implantation have gradually expanded as advancements in technology have evolved, resulting in improved audiologic outcomes for both adult and children. There remains a significant underutilization of cochlear implant technology in the United States, and recognition of the potential benefits of cochlear implantation for non-traditional indications is critical for encouraging the evolution of candidacy criteria. Adult cochlear implantation candidacy has progressed from patients with bilateral profound sensorineural hearing loss (SNHL) to include patients with greater degrees of residual hearing, single-sided deafness and asymmetric hearing, and atypical etiologies of hearing loss (eg, vestibular schwannoma, Ménière's disease, and otosclerosis). Indications for pediatric cochlear implantation have similarly evolved from children with bilateral severe to profound SNHL to implanting children at a younger age, including those with residual hearing, asymmetric hearing loss, inner ear malformations, as well as cochlear nerve deficiency. In this editorial, the literature investigating cochlear implantation for nontraditional indications is reviewed with an aim to use the best available evidence to encourage the evolution of candidacy criteria.

Cochlear implant surgery through oval window: A novel approach in a child with facial nerve aberration

Cochlear implantation is safe for simple case presentations. However, facial nerve (FN) aberrations may impede insertion of the electrode through a round window and increase the risk of iatrogenic FN injury. We developed a novel method of cochlear implantation, a present the case of a child with FN aberrations. Inferior displacement of a horizontal segment of FN lay on the surface of th e promontory, obscuring the round window. The oval window was used and the electrode successfully inserted. No postoperative complications occurred, and significant improvement in speech perception was achieved. This novel approach is suitable for patients with FN aberrations.

Balance function after cochlear implant and inner ear anomaly: Comparison of dynamic posturography

INTRODUCTION

Patients with sensorineural hearing loss suffer concomitant vestibular dysfunction that is more prevalent in patients with inner ear anomaly and could be aggravated with cochlear implantation. To assess the vestibular dysfunction in patients with cochlear implantation, we compared their results with those of patients with and without inner ear anomaly.

MATERIALS AND METHODS

This is a historical cohort study lasting for 20 years on 50 patients with cochlear implantation. All patients underwent dynamic posturography and Bruininks-Oseretsky Test.

RESULTS

Twenty-two (44%) of the participants showed some types of inner ear anomaly. The frequency of abnormal Bruininks-Oseretsky Test was 45.5% and 10.7% (P = .005, odds ratio [OR] = 6.9). Abnormal composite was seen in 77.3% and 21.4%, respectively (P < .001; OR = 12.5). The mean strategy score in the fifth condition of the sensory organization test was 25.0 ± 20.4 in patients with inner ear anomaly, whereas it was 44.1 ± 18.9 in those without it (P = .001).

CONCLUSION

Balance capability in cochlear implantation patients with inner ear anomaly compared to those without inner ear anomaly was worse. More vestibular rehabilitation treatment plans are suggested for these patients.

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.

Impact of cochlear abnormalities on hearing outcomes for children with cochlear implants

OBJECTIVE

Evaluate the impact of cochlear anomalies on hearing outcomes for pediatric patients with cochlear implants.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary care center.

SUBJECTS AND METHODS

Charts were retrospectively reviewed for cases where pediatric cochlear implant surgery was performed between 2002 and 2018 at a single, tertiary care institution. Patients were divided into groups based on the presence or absence of radiological cochlear abnormalities, which were further classified as low or high risk anomalies. Hearing outcomes were evaluated by measuring pure tone averages and word recognition scores preoperatively, 3 and 12 months postoperatively, in addition to the most recent test results.

RESULTS

There were 154 ears implanted in our cohort of 100 patients. 107 ears had normal cochlear anatomy, 31 had low risk, and 16 had high risk abnormalities. The most common modality of preoperative imaging was CT scan. Postoperative mean pure tone average (PTA) was significantly higher in patients with inner ear anomalies compared to those with normal anatomy. No significant difference in PTA was noted between low versus high risk patients. <50% of patients had word recognition scores available within the first year following surgery.

CONCLUSION

Abnormalities of the inner ear significantly influenced hearing outcomes over time following cochlear implant surgery when compared to pediatric patients with normal anatomy. Obtaining hearing testing can be difficult in very young children and therefore future studies are warranted to further investigate the impact that cochlear abnormalities may have on hearing outcomes following cochlear implant surgery.

A Ten-Year Review of Audiological Performance in Children with Inner Ear Abnormalities after Cochlear Implantation in Singapore

OBJECTIVES

To evaluate children with inner ear malformations following cochlear implantation (CI) in a tertiary pediatric hospital in Singapore to identify factors influencing outcomes after CI.

METHODS

This is a retrospective cohort study of children aged 0 to 18 years, who had CI between 2000 and 2013. Demographic information, data on risk factors, type of inner ear malformation (IEM), age at implantation, speech pre- and postimplantation, and duration of follow-up were collected from clinical records. Operative details and audiological outcomes were also analyzed.

RESULTS

A total of 70 children underwent 83 CI surgeries. The mean age of the patients was 4.05 ± 3.17 years (range 1-18 years). Twenty patients (28.57%) had abnormal CT scan findings. CSF gusher occurred in 15 out of 26 CI (57.69%) in the group with IEM. Nine out of twenty patients (45.00%) had poor IT-MAIS scores prior to implantation. The average preoperative IT-MAIS score for children with anomalous inner ear anatomy was 14.1. The older CI patients, 3/20 (15.00%), mean age 8.33 years (range 7-10 years), were mostly referred for persistently unclear speech following hearing aids. Eleven patients (55.00%) had good speech and aided hearing threshold within speech limits after CI and were eligible for reintegration into mainstream schools. Five patients (25.00%) had improvement in speech but continued to receive education in special schools. Four patients (20.00%) had poor progress after surgery.

CONCLUSION

The presence of absent cochlear nerve, electrode folding, and underlying neurological disorders seemed to be associated with poorer outcomes.

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.

E-ABR in Patients with Cochlear Implant: A Comparison between Patients with Malformed Cochlea and Normal Cochlea

OBJECTIVES

This study aims to compare the electrical auditory brainstem response (EABR) following cochlear implant (CI) surgery in pediatric subjects with cochlear malformation and a normal cochlea, in order to assess the sensitivity of EABR and to evaluate the surgery outcome.

MATERIALS AND METHODS

A total of 26 pediatric subjects who were deaf and scheduled for CI surgery were enrolled into this case control study. Group A (n=20) included subjects with a normo-conformed cochlea. Group B (n=6) included subjects with cochlear malformation. Subjects were evaluated with EABR immediately (T0) and 6 months (T1) post-CI surgery. The EABR Waves III and V average amplitude and latency were compared across time, separately for each group, and across groups, separately for each time.

RESULTS

Auditory brainstem response (ABR) could only be recorded in Group A. We were able to record EABR from all subjects at T0 and T1, and waves III and V were present in all the recorded signals. There were no statistically significant differences between T0 and T1 in EABR Waves III and V in terms of average amplitude and latency in neither group. When comparing Groups A and B, the only statistically significant difference was the average amplitude of wave V, both at T0 and T1.

CONCLUSION

EABR is a valid tool to measure the auditory nerve integrity after CI surgery in patients with a normal and malformed cochlea, as shown by its ability to measure waves III and V when ABR is absent. The EABR testing should be performed before and after CI surgery, and EABR should be used as a measure of outcome, especially in patients with a malformed cochlea.

Sensorineural Hearing Loss in the Nonimplanted Ear Following Cochlear Implantation in a Patient With Bilateral Enlarged Vestibular Aqueducts

OBJECTIVE

To document the case of a patient with bilateral enlarged vestibular aqueducts who experienced sensorineural hearing loss in the nonimplanted ear following unilateral cochlear implantation complicated by perilymph gusher requiring lumbar drain insertion and to highlight the need to counsel regarding the risk of potential hearing loss to the contralateral ear when preparing for cochlear implants in the setting of inner ear malformations.

PATIENTS

One patient with bilateral enlarged vestibular aqueducts in a tertiary referral center.

INTERVENTION(S)

Cochlear implantation complicated by perilymph gusher requiring lumbar drain insertion.

MAIN OUTCOME MEASURE(S)

Bone conduction hearing thresholds, word recognition scores.

RESULTS

The patient underwent unilateral cochlear implantation, which was complicated by a perilymphatic gusher and necessitated placement of an intraoperative lumbar drain. On postoperative day 1, the patient reported hearing loss in the opposite ear. The word recognition score in the contralateral ear dropped from 24% at preimplantation to 8% at 2-weeks postimplantation, and did not improve at 6 months postimplantation. Moreover, the bone conduction threshold at 1 kHz worsened from 20 dB preoperatively to no response at 75 dB (the limit of the testing equipment) at 2-weeks postoperatively and only partially improved to 40 dB at 6 months postimplantation.

CONCLUSION

As patients with inner ear malformations potentially have direct high-pressure anatomical connections between the perilymphatic spaces and the cerebrospinal fluid, they are at risk of hearing loss in the nonimplanted ear during cochlear implantation. This case highlights the need for potential additional patient counseling regarding this risk in the nonimplanted ear.

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.

Rare case of bilateral aural atresia and cochlear dysplasia: when cochlear implantation is not the answer

OBJECTIVE AND IMPORTANCE

Reports of patients with concurrent middle and inner ear anomalies are rare. These patients present a surgical challenge for cochlear implantation. The surgical risk must be weighed against the predicted benefit of the patient's hearing outcome and subsequent development of speech and language as well as their quality of life.

CLINICAL PRESENTATION

Thirteen-year-old boy presented to the Otology clinic for auditory rehabilitation options. He has mild developmental delay, is non-verbal and communicates via American Sign Language. He was born with bilateral aural atresia and never wore amplification. On exam he has grade 1 microtia and complete ear canal atresia bilaterally. His behavioural hearing test shows profound sensorineural hearing loss of both ears. The computed tomography scan shows bilateral underdeveloped and completely opacified mastoid and middle ear, complete bony atresia of the ear canals, and an under-partitioned cochlea with poorly defined modiolus, among other abnormalities. The patient and his family were counselled on the available options as well as the need for any further studies.

INTERVENTION

Counselling of patient and family.

CONCLUSION

While there have been reports in the literature of performing cochlear implantations in patients with a concurrent atresia and cochlear dysplasia, these were patients whose degree of inner ear anomalies was relatively minor and their prognosis of a good audiological outcome was favourable. The presented case is that of a patient for whom the surgical approach to the cochlea alone would be difficult. More importantly, his quality of life would not significantly improve in light of the predicted limited hearing and language development outcomes, given the severity of his inner ear abnormalities, limited communication abilities, prolonged period of deafness and developmental delays.

Preoperative simulation unveiled undetected surgical difficulties in a case of cochlear implantation

We herein report a case in which extensive preparation changed a difficult-to-treat patient into an easy one. We performed a revision cochlear implantation on a patient whose first procedure had been aborted due to unidentified difficulties. During a series of thorough three-dimensional simulations, we found that the patient in question had a normal cochlea but the cochlea was placed in an unusual position and orientation. This condition is difficult to detect on standard preoperative radiographic images. Through this simulation, we were able to propose a surgical plan to avoid making the same mistakes as the first surgeon. We present this case not as a rare difficult case of an unfortunate patient but instead emphasise the importance of performing surgical simulation and looking for non-obvious difficulties. This case is an example of the success that can be achieved with such extensive preparation.

The Use of Lexical Neighborhood Test (LNT) in the Assessment of Speech Recognition Performance of Cochlear Implantees with Normal and Malformed Cochlea

The present study aims to use the model-based test Lexical Neighborhood Test (LNT), to assess speech recognition performance in early and late implanted hearing impaired children with normal and malformed cochlea. The LNT was administered to 46 children with congenital (prelingual) bilateral severe-profound sensorineural hearing loss, using Nucleus 24 cochlear implant. The children were grouped into Group 1-(early implantees with normal cochlea-EI); n = 15, 31/2-61/2 years of age; mean age at implantation-3½ years. Group 2-(late implantees with normal cochlea-LI); n = 15, 6-12 years of age; mean age at implantation-5 years. Group 3-(early implantees with malformed cochlea-EIMC); n = 9; 4.9-10.6 years of age; mean age at implantation-3.10 years. Group 4-(late implantees with malformed cochlea-LIMC); n = 7; 7-12.6 years of age; mean age at implantation-6.3 years. The following were the malformations: dysplastic cochlea, common cavity, Mondini's, incomplete partition-1 and 2 (IP-1 and 2), enlarged IAC. The children were instructed to repeat the words on hearing them. Means of the word and phoneme scores were computed. The LNT can also be used to assess speech recognition performance of hearing impaired children with malformed cochlea. When both easy and hard lists of LNT are considered, although, late implantees (with or without normal cochlea), have achieved higher word scores than early implantees, the differences are not statistically significant. Using LNT for assessing speech recognition enables a quantitative as well as descriptive report of phonological processes used by the children.

Clinical outcomes following cochlear implantation in children with inner ear anomalies

OBJECTIVE

A significant proportion of children with congenital hearing loss who are candidates for cochlear implants (CIs) may have inner ear malformations (IEMs). Surgical and speech outcomes following CI in these children have not been widely reported.

METHODS

The charts of children who were evaluated for a CI between 1/1/1986 and 12/31/2014 at a university-based tertiary level pediatric cochlear implant center were reviewed. Principal inclusion criteria included (i) age 1-18 years, (ii) history of bilateral severe to profound sensorineural hearing loss, and (iii) limited benefit from binaural amplification. Exclusion criteria included (i) underlying diagnosis of neurodevelopmental disorder and (ii) lack of follow up for speech assessment if a CI was performed. The following outcome measures were reviewed: (i) imaging findings with magnetic resonance imaging or high resolution computed tomography, (ii) intraoperative complications, and (iii) speech perception categorized as the ability to perceive closed set, open set, or none.

RESULTS

The prevalence of IEMs was 27% (102 of 381), of which 79% were bilateral. Cochlear dysplasia accounted for 30% (40 of 136) of the anomalies. Seventy-eight of the 102 patients received a CI (78%). Surgery was noted to be challenging in 24% (19 of 78), with a perilymphatic gusher being the most common intraoperative finding. Cochlear dysplasia, vestibular dysplasia and cochlear nerve hypoplasia were associated with poor speech perception (open OR closed set speech recognition scores, 0-23%), although the outcomes in children with enlarged vestibular aqueduct were similar to those of children with normal inner ear anatomy (65%).

CONCLUSIONS

Cochlear implantation is safe in children with IEMs. However, the speech perception outcomes are notably below those of patients with normal anatomy, with the exception of when an enlarged vestibular aqueduct is present.

Inner ear malformations: a practical diagnostic approach

Pediatric sensorineural hearing loss is a major cause of disability; although inner ear malformations account for only 20-40% of all cases, recognition and characterization will be vital for the proper management of these patients. In this article relevant anatomy and development of inner ear are surveyed. The role of neuroimaging in pediatric sensorineural hearing loss and cochlear preimplantation study are assessed. The need for a universal system of classification of inner ear malformations with therapeutic and prognostic implications is highlighted. And finally, the radiological findings of each type of malformation are concisely described and depicted. Computed tomography and magnetic resonance imaging play a crucial role in the characterization of inner ear malformations and allow the assessment of the anatomical structures that enable the selection of appropriate treatment and surgical approach.

Management of surgical difficulties during cochlear implant with inner ear anomalies

OBJECTIVE

To review the difficulties that can occur during cochlear implant surgery in patients with inner ear abnormalities and the management thereof.

METHODS

A retrospective chart review of 316 patients who received cochlear implants was conducted. The data collected included the types of inner ear anomalies, intraoperative findings, and the clinical management strategies. A review of the literature was also performed.

RESULTS

A total of 24 patients with inner ear malformations who underwent 28 total cochlear implant procedures were identified. The anomalies included isolated large vestibular aqueducts in 8 (33.3%) patients, isolated semicircular canal dysplasia in 8 (33.3%) patients, classical Mondini malformation in 7 (29.1%) patients, and cochlear hypoplasia in 1 (4.1%) patient. Four (14.2%) patients exhibited intraoperative cerebrospinal fluid (CSF) gushers. One patient experienced delayed facial nerve paralysis, and an electrode was partially inserted into one patient. In 2 (7.14%) cases, the surgeries were aborted because of difficulties.

CONCLUSION

Cochlear implantation for inner ear anomalies can be performed safely. Special attention should be given to preoperative imaging to anticipate the potential intraoperative risks that can occur in inner ear anomaly cases. Every surgery should be planned with a safe approach and specific requirements, e.g., regarding electrode type, and the surgeries must be performed by experienced surgeons who are capable of modifying their technique according to the surgical findings.

Facial nerve anomalies in paediatric cochlear implant candidates: radiological evaluation

Background:

Pre-operative radiological identification of facial nerve anomalies can help prevent intra-operative facial nerve injury during cochlear implantation. This study aimed to evaluate the incidence and configuration of facial nerve anomalies and their concurrence with inner-ear anomalies in cochlear implant candidates.

Methods:

Inner-ear and concomitant facial nerve anomalies were evaluated by magnetic resonance imaging and temporal high-resolution computed tomography in 48 children with congenital sensorineural hearing loss who were cochlear implant candidates.

Results:

Inner-ear anomalies were present in 11 out of 48 patients (23 per cent) and concomitant facial nerve anomalies were present on 7 sides in 4 patients (7 per cent of the total). Facial nerve anomalies were accompanied by cochlear or vestibular malformation.

Conclusion:

Potential facial nerve abnormalities should always be considered in patients with inner-ear anomalies. Pre-operative facial nerve imaging can increase the surgeon's confidence to plan and perform cochlear implantation. Magnetic resonance imaging should be used to detect inner-ear anomalies; if these are identified, temporal high-resolution computed tomography should be used to evaluate the facial nerve.

Cerebrospinal Fluid Leak in Cochlear Implantation: Enlarged Cochlear versus Enlarged Vestibular Aqueduct (Common Cavity Excluded)

Objective. To share our experience of cerebrospinal fluid gusher in cochlear implantation in patients with enlarged cochlear or vestibular aqueduct. Study Design. Case series with comparison and a review of the literature. Methods. A retrospective study was performed. Demographic and radiological results of patients with enlarged cochlear aqueduct or enlarged vestibular aqueduct in 278 consecutive cochlear implant recipients, including children and adults, were evaluated between January 2000 and December 2015. Results. Six patients with enlarged cochlear aqueduct and eight patients with enlarged vestibular aqueduct were identified. Cerebrospinal fluid gusher occurs in five subjects with enlarged cochlear aqueduct and in only one case of enlarged vestibular aqueduct. Conclusion. Based on these findings, enlarged cochlear aqueduct may be the best risk predictor of cerebrospinal fluid gusher at cochleostomy during cochlear implant surgery despite enlarged vestibular aqueduct.

Cochlear implantation in Pendred syndrome and non-syndromic enlarged vestibular aqueduct - clinical challenges, surgical results, and complications

OBJECTIVE

To explore specific clinical issues, surgical results, and complications of 80 cochlear implantations (CI) in 55 patients with Pendred syndrome (PS) or non-syndromic enlarged vestibular aqueduct (NSEVA).

BACKGROUND

Previous studies have focused either on unselected case series or on populations with mixed cochlear malformations. PS/NSEVA accounts for up to 10% of congenital SNHL, rendering this a large group of cochlear implant candidates. The abnormal inner ear anatomy of these patients may be associated with a lower surgical success rate and a higher rate of complications.

STUDY DESIGN

Retrospective review of patients' medical records and CT/MRI.

SETTING

Tertiary referral center.

MATERIALS AND METHODS

The medical records and CT/MRI images of 55 PS/NSEVA patients receiving 80 cochlear implantations from 1982-2014 were reviewed. Demographic data, surgical results, intra-operative incidents, and post-operative complications were retrieved.

RESULTS

Complications occurred in 36% of implantations; 5% hereof major complications. Gushing/oozing from the cochleostoma occurred in 10% of implantations and was related to transient, but not prolonged post-operative vertigo.

CONCLUSION

Intra-operative risks of gushing/oozing and post-operative vertigo are the primary clinical issues in PS/NSEVA patients regarding CI. Nonetheless, the surgical success rate is high and the major complication rate is low; similar to studies of unselected series of CI recipients.

Bilateral Sequential Cochlear Implantation in Patients With Enlarged Vestibular Aqueduct (EVA) Syndrome

OBJECTIVES

To analyze audiometric outcomes after bilateral cochlear implantation in patients with isolated enlarged vestibular aqueduct (EVA) syndrome and associated incomplete partition (IP) malformations. Secondary objective was to analyze rate of cerebrospinal fluid (CSF) gusher in patients with IP-EVA spectrum deformities and compare this with the existing literature.

STUDY DESIGN

Retrospective chart review.

METHODS

Thirty-two patients with EVA syndrome who received unilateral or bilateral cochlear implants between June 1999 and January 2014 were identified in the University Hospitals Case Medical Center cochlear implant database. Isolated EVA (IEVA) and Incomplete Partition Type II (IP-II) malformations were identified by reviewing high-resolution computed tomography (HRCT) imaging. Demographic information, age at implantation, surgical details, postimplantation audiometric data including speech reception thresholds (SRT), word, and sentence scores were reviewed and analyzed. Intra- and postoperative complications were analyzed as well and compared with the literature.

RESULTS

Seventeen patients (32 implanted ears) had pediatric cochlear implantation for EVA-associated hearing loss. Data from 16 controls (32 implanted ears) were used to compare audiometric and speech outcomes of EVA cohort. Mean age at implantation was 6.8 years for EVA cohort and 6.0 years for controls. There was no statistically significant difference in long-term postoperative SRT, monaurally aided word scores, and binaurally tested word scores between pediatric EVA group and controls. The EVA patients had a long-term mean sentence score of 85.92%. A subset of EVA patients implanted at mean age of 3.18 years (n = 15 ears) had similar audiometric outcomes to another control group with Connexin 26 mutations (n = 20 ears) implanted at a similar age. Further subset analysis revealed no significant differences in age at implantation, SRT, and word scores in patients with IEVA and IP-II malformation. There was no significant association between size of vestibular aqueduct and age at implantation. There was no CSF gusher or other intra- or postoperative complications reported in our series.

CONCLUSION

Bilateral sequential cochlear implantation can be performed safely in patients with EVA. Audiometric outcomes are excellent and comparable to pediatric cochlear implant patients with no malformations. CSF gusher rates can be minimized by trans-round window approach. Further long-term studies are needed to identify differences within IP-EVA spectrum deformities, audiometric outcomes, and proportions of EVA patients who will need cochlear implantation for hearing rehabilitation.

Temporal High-Resolution Computed Tomography and Magnetic Resonance Imaging of Congenital Inner Ear Anomalies in Children

Imaging plays an important role in determining indications of cochlear implantation and choosing candidates for the procedure in children. Temporal high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) can display precisely the complex anatomic structure of inner ear. Although HRCT permits detailed imaging of bony structures, MRI gives valuable information about membranous labyrinth, internal acoustic canal, and vestibulocochlear nerve. Magnetic resonance imaging examination of the brain should be performed at the same time to evaluate any coexistent brain parenchymal abnormality. These imaging modalities are complementary methods in evaluating congenital inner ear anomalies. The aim of this pictorial essay is to reviewing temporal HRCT and MRI findings of congenital inner ear anomalies.

Communication outcomes following cochlear implantation in a child with cystic cochleovestibular anomaly

Cochlear implantation is one of the best amongst the various management options available for children and adults with severe to profound sensorineural hearing loss. Inner ear and internal auditory canal (IAC) malformations accounts to approximately 25% of congenital sensorineural hearing loss in children. The primary goal of this report was to evaluate the communication outcomes after cochlear implantation in a child with cystic cochleovestibular anomaly (CCVA). The child was evaluated through various standardized outcome measures at regular intervals to track the progress in terms of auditory and spoken language skills. The scores on Categories of Auditory Perception (CAP), Meaningful Auditory Integration Scale (MAIS), Speech Intelligibility Rating (SIR), Meaningful Use of Speech Scale (MUSS), and listening and spoken language skills showed a significant leap in 12 months duration post implantation. The report thus highlights and correlates the significant progress in auditory and spoken language skills of the child with congenital malformations to appropriate auditory rehabilitation and intensive parental training.

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.

Usefulness of measuring electrically evoked auditory brainstem responses in children with inner ear malformations during cochlear implantation

CONCLUSIONS

EABR is a reliable and effective way of objectively confirming device function and implant-responsiveness of the peripheral auditory neurons up to the level of the brainstem in cases of inner ear malformation.

OBJECTIVE

To investigate the usefulness of measuring the intra-operative electrically evoked compound action potential (ECAP) and electrically evoked auditory brainstem response (EABR) in patients with and without congenital inner ear anomalies during cochlear implantation.

METHOD

Thirty-eight consecutive children (40 ears) aged 5 or younger with congenital profound hearing loss. Twenty-four (25 ears) lacked congenital inner ear anomalies. The 14 patients (15 ears) with a malformation had common cavities (four ears), incomplete partition type I (three ears), cochlea hypoplasia type III (three ears), enlarged vestibular aqueduct (four ears), and cochlear nerve canal stenosis (one ear). Main outcome measures are ECAP and EABR responses.

RESULTS

Of the 25 ears lacking any malformation, 21, three, and one showed 'Good', 'Variable', and 'No' ECAP responses, respectively, and 24 and one showed 'Good' and 'Variable' intra-cochlear responses, respectively. Of the 15 ears with a malformation, two showed 'Good' ECAP responses, nine had 'Variable' ECAP responses, and four showed 'No' ECAP responses. Moreover, five showed 'Good' EABR responses and 10 showed 'Variable' EABR responses.

Vaccination recommendations and risk of meningitis following cochlear implantation

PURPOSE OF REVIEW

The Centers for Disease Control and Prevention has established vaccination guidelines for cochlear implant recipients to address the concern for implant-associated bacterial meningitis. Since their inception in 2002, these guidelines have undergone several revisions. We review the rationale and development of the current vaccination schedule.

RECENT FINDINGS

Bacterial meningitis is a rare yet potentially life-threatening complication of cochlear implantation. The recommendations for pneumococcal vaccination have evolved to a state in which nearly all cochlear implant patients receive a combination of both the PCV7 or PCV13 and PPSV23.

SUMMARY

Streptococcus pneumoniae vaccinations have dramatically decreased the incidence of serotype-specific invasive pneumococcal disease across all age groups. However, the optimal timing of immunization remains unclear in cochlear implant candidates.

Non-syndromic hereditary sensorineural hearing loss: review of the genes involved

BACKGROUND

Hereditary sensorineural hearing loss is the most frequently occurring birth defect. It has profound effects for the individual and is a substantial burden on society. Insight into disease mechanisms can help to broaden therapeutic options and considerably lower lifetime social costs. In the past few decades, the identification of genes that can cause this type of hearing loss has developed rapidly.

OBJECTIVE

This paper provides a concise overview of the currently known genes involved in non-syndromic hereditary hearing loss and their function in the inner ear.