Prognostic Value of Electrophysiological and MRI Findings for Pediatric Cochlear Implant Outcomes: A Systematic Review

PURPOSE

Magnetic resonance imaging (MRI), electric compound action potential (eCAP), and electric auditory brainstem response (eABR) are among the routine assessments performed before and/or after cochlear implantation. The objective of this review was to systematically summarize and critically appraise existing evidence of the prognostic value of eCAP, eABR, and MRI for predicting post-cochlear implant (CI) speech perception outcomes in children, with a particular focus on the lesion site.

METHOD

The present systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. Three electronic databases (ProQuest, PubMed, and Scopus) were searched with no restrictions on language, publication status, or year of publication. Studies on children identified with sensorineural hearing loss, auditory neuropathy spectrum disorder, cochlear nerve deficiency, or cochleovestibular nerve abnormalities reporting the relevance of eCAP, eABR, and/or MRI results to CI speech perception outcomes were included. The literature search yielded 1,887 publications. Methodological quality and strength of evidence were assessed by the Crowe Critical Appraisal Tool and the Grading of Recommendations Assessment, Development, and Evaluation tool, respectively.

RESULTS

Of the 25 included studies, the relevance of eCAP, eABR, and/or MRI findings to post-CI speech perception outcomes was reported in 10, 11, and 11 studies, respectively. The studies were strongly in support of the prognostic value of eABR and MRI for CI outcomes. However, the relevance of eCAP findings to speech perception outcomes was uncertain.

CONCLUSION

Despite the promising findings, caution is warranted in interpreting them due to the observational and retrospective design of the included studies, as well as the heterogeneity of the population and the limited control of confounding factors within these studies.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.26169859.

Trends in research on cochlear implantation with inner ear malformation: a bibliometric and visualization analysis from 1986 to 2024

OBJECTIVE

The aim of this study was to conduct a bibliometric and visualization analysis of research on cochlear implantation (CI) for inner ear malformations (IEMs) from 1986 to 2024.

METHODS

A comprehensive literature search was performed using the Web of Science Core Collection Database, resulting in the identification of 431 relevant publications. Various data analysis and visualization tools, including VOSviewer, CiteSpace, and Bibliometrix, were utilized to analyze annual publication outputs, countries/regions and institutions, authors, journals and studies, keywords, and theme evolution.

RESULTS

The study revealed an overall increasing trend in research output on CI for IEMs, with significant contributions from countries such as the United States, China, Turkey, Germany, and Italy. The analysis also identified key authors, research teams, journals, and studies that have made substantial contributions to the field. Furthermore, the study highlighted important research hotspots and trends, such as the classification of IEMs, outcomes of CI for IEMs, and the management of pediatric patients with IEMs.

CONCLUSION

The findings of this study provide a comprehensive overview of the research landscape surrounding CI for IEMs. The results serve as a basis for future research topic selection and emphasize the need for enhanced international collaboration and the publication of high-impact research to further advance this field.

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.

The Acoustic Change Complex in Response to Frequency Changes and Its Correlation to Cochlear Implant Speech Outcomes

One of the biggest challenges that face cochlear implant (CI) users is the highly variable hearing outcomes of implantation across patients. Since speech perception requires the detection of various dynamic changes in acoustic features (e.g., frequency, intensity, timing) in speech sounds, it is critical to examine the ability to detect the within-stimulus acoustic changes in CI users. The primary objective of this study was to examine the auditory event-related potential (ERP) evoked by the within-stimulus frequency changes (F-changes), one type of the acoustic change complex (ACC), in adult CI users, and its correlation to speech outcomes. Twenty-one adult CI users (29 individual CI ears) were tested with psychoacoustic frequency change detection tasks, speech tests including the Consonant-Nucleus-Consonant (CNC) word recognition, Arizona Biomedical Sentence Recognition in quiet and noise (AzBio-Q and AzBio-N), and the Digit-in-Noise (DIN) tests, and electroencephalographic (EEG) recordings. The stimuli for the psychoacoustic tests and EEG recordings were pure tones at three different base frequencies (0.25, 1, and 4 kHz) that contained a F-change at the midpoint of the tone. Results showed that the frequency change detection threshold (FCDT), ACC N1' latency, and P2' latency did not differ across frequencies (p > 0.05). ACC N1'-P2 amplitude was significantly larger for 0.25 kHz than for other base frequencies (p < 0.05). The mean N1' latency across three base frequencies was negatively correlated with CNC word recognition (r = -0.40, p < 0.05) and CNC phoneme (r = -0.40, p < 0.05), and positively correlated with mean FCDT (r = 0.46, p < 0.05). The P2' latency was positively correlated with DIN (r = 0.47, p < 0.05) and mean FCDT (r = 0.47, p < 0.05). There was no statistically significant correlation between N1'-P2' amplitude and speech outcomes (all ps > 0.05). Results of this study indicated that variability in CI speech outcomes assessed with the CNC, AzBio-Q, and DIN tests can be partially explained (approximately 16-21%) by the variability of cortical sensory encoding of F-changes reflected by the ACC.

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

OBJECTIVE

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

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary referral center.

PATIENTS

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

INTERVENTION

None.

MAIN OUTCOME MEASURE

Most recent consonant-nucleus-consonant word score.

RESULTS

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

CONCLUSIONS

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

Clinical evaluation of cochlear implantation in children younger than 12 months of age

IMPORTANCE

Cochlear implantation (CI) is an effective therapy for patients with severe to profound sensorineural hearing loss. It remains controversial whether children younger than 12 months of age should undergo CI.

OBJECTIVE

To evaluate the safety and effectiveness of CI in children younger than 12 months of age.

METHODS

We performed a retrospective study of clinical data of pediatric patients younger than 12 months of age who underwent CI and were followed up for 1 to 2 years. Patients' developmental levels were evaluated by the Gesell score before CI. Intraoperative and postoperative complications were recorded to evaluate the safety of CI. Auditory and speech abilities were scored by the LittlEARS® auditory questionnaire (LEAQ), categories of auditory performance (CAP), speech intelligibility rating (SIR), infant-toddler meaningful auditory integration scale (IT-MAIS), and meaningful use of speech scale (MUSS) at 1, 2, 3, 6, 9, and 12 months after CI. The associations between clinical characteristics before CI and postoperative scores at 1 year after CI were analyzed by the linear mixed-effects model.

RESULTS

Eighty-nine children (47 boys and 42 girls) were included in this study (mean age at CI, 9.2 ± 1.6 months). Sixteen patients were diagnosed with cochlear malformation and 16 underwent bilateral CI. No severe complications occurred in any patients. The mean developmental quotient of the Gesell score was 78.00 ± 10.03. The median LEAQ scores were 0, 5, 10, 16, 22, 26 and 30 before and at 1, 2, 3, 6, 9, and 12 months after CI, respectively. These findings implied that the LEAQ score greatly improved in the first year after CI. The overall CAP, SIR, IT-MAIS, and MUSS scores also increased with increasing duration after CI. No significant associations were detected between clinical characteristics (age, sex, implant number, pre-CI Gesell score, and inner ear malformation) and LEAQ outcomes at 12 months after CI.

INTERPRETATION

With increasing duration after CI, auditory and speech behavior dramatically improve in young children. Our findings indicate that CI is feasible for children younger than 12 months of age.

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.

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.

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.

The new classification system for inner ear malformations: the INCAV system

CONCLUSIONS

The proposed INCAV system standardizes reporting of inner ear malformations; gives adequate information about the structures of inner ear; defines the ears which could not be classified before; and helps in the selection of the ear as the cochlear implant candidate. Also it is easy-to-use for radiologists, and useful to the referring otolaryngologists.

OBJECTIVE

This study was conducted to explore a more specific, definitive classification system which was based on radiological criteria for inner ear malformations.

METHOD

This study found 43 patients who had inner ear malformations, magnetic resonance (MR), and computed tomography (CT) imaging, together with the retrospective evaluation of the medical records between August 2010 and February 2015. It analyzed inner ear structures by dividing five sub-groups and each sub-group was given a letter: internal acoustic canal (I), cochlear nerve (N), cochlea (C), vestibular aqueduct (A) and vestibule (V). Based on their malformations, these anatomical structures have been assigned grades and have been classified by using increasing numbers which were dependent to increasing order of severity of the malformation.

RESULTS

Among these 43 patients, there were six normal (I₀N₀C₀A₀V₀) and 80 inner ear malformations. All of the ears were defined successfully by the INCAV system.

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.

Correlation analysis of phenotype and genotype of GJB2 in patients with non-syndromic hearing loss in China

BACKGROUND

Disease-associated mutations in GJB2 gene are one of the major reasons that can cause non-syndromic sensorineural hearing loss (NSHL). GJB2 gene deafness has various clinical phenotypes. This study aims to analyze characteristics and relationships of clinical phenotypes through analyzing 1481 NSHL cases and 190 GJB2 deafness patients (with dual gene mutations).

PATIENTS AND METHODS

All the patients diagnosed as deaf disease molecular diagnostics were obtained from the people's liberation army general hospital from March 2007 to March 2011. The accession number of GJB2 was NM_004004 in GenBank, and sequence alignment and annotation were performed using GeneTool software.

RESULTS

In NSHL patients, mutated allele frequency in GJB2 was 20.57%, and the preponderant type was c.235delC (11.84%) followed by c.109G>A (3.75%). Mutation rate of double allelic gene was 16.18%, including 8.43% of homozygous mutation rate and 7.75% of recombination heterozygosis mutation. Moreover, auditory threshold of GJB2 biallelic marker was associated with ages of onset, while no significant correlation was detected with disease time and whether the inner ear malformation. Similar clinical phenotype could be detected between patients with c.109G>A dual gene mutation and dual gene mutation. However, in the aspect of hearing impairment, the phenomenon of pathopoiesia caused by mutation of c.109G>A was poorer than the other mutations, and even near those patients without pathogenic mutations.

CONCLUSION

Our study further shows the definite relationship of clinical phenotype and genotype in GJB2 gene correlated deafness, and these results can provide basis for revealing pathogenesis, gene diagnosis and consult of deafness. The level of evidence in the study is level 4 (case series).