Surgical Outcomes After Cochlear Implantation in Children With Incomplete Partition Type I: Comparison With Deaf Children With a Normal Inner Ear Structure

[Relationship between imaging features and intraoperative perilymph gusher in patients with Mondini inner ear malformation]

Objective:To investigate the relationship between imaging characteristics and intraoperative perilymph gusher in patients with Mondini inner ear malformation in cochlear implantation, in order to provide basis and clinical guidance for predicting of intraoperative perilymph gusher before cochlear implantation. Methods:According to Sennaroglu's classification method, children with severe sensorineural hearing loss screened from January 2020 to December 2021 were divided into Mondini group, simple enlarged vestibular aqueduct group and normal inner ear group according to inclusion criteria strictly. The images of temporal bone HRCT and inner ear MRI were post-processed, some relative indicators were measured, including cochlear height and width of vestibular aqueduct, etc., and the gusher situation during cochlear implantation was recorded. The mean value of each indicator among the three groups were compared respectively, and the differences of each indicator between the gusher group and the non-gusher group were analyzed. Results:There were statistically significant differences in cochlear height, length of cochlear bottom turn, width of cochlear aperture, vestibular length and vestibular width among the Mondini group（24 cases）, simple EVA group（15 cases） and normal inner ear group（28 cases）. The incidence of gusher of Mondini group in cochlear implantation was 30.77%（8/26）. The outer diameter of the VA（[3.10±0.74]mm） and the middle width of the VA（[1.90±0.68] mm） in the gusher group were wider than those in the non-gusher group, and the difference was statistically significant. The incidence of intraoperative gusher in patients with EVA was 20.00%（3/15）, and there was statistically significant difference in the length of endolymph sac between gusher group and non-gusher group（P<0.05）. Conclusion:The causes of intraoperative perilymph gusher in patients with Mondini inner ear malformation are complex. The enlarged vestibular aqueduct may be one of the anatomical basis. Whether it can be used to guide the preoperative assessment of the risk of intraoperative perilymph gusher need to be further confirmed by a large sample of clinical research from multiple centers in the future.

Electrostatic Discharge (ESD) as a Cause of Facial Nerve Stimulation After Cochlear Implantation: A Case Report

OBJECTIVE

To discuss persistent facial nerve stimulation (FNS) related to repeated electrostatic discharge (ESD) shock following cochlear implantation.

METHODS

Single case report with literature review.

RESULTS

FNS is a feared complication after cochlear implantation, occurring in approximately 7% of cases, with most patients having anatomic abnormalities. The presented case has no anatomical abnormalities but reported frequent environmental static shock. FNS during the first 1 to 3 seconds of processor attachment caused a significant decrease in the patient's quality of life, requiring subsequent re-implantation with full resolution.

CONCLUSIONS

FNS is a complication of cochlear implantation that can cause a great deal of distress and discomfort. Frequent electrostatic discharge (ESD) contributed to device malfunctioning and FNS in a patient with otherwise normal anatomy and should be avoided if possible.

Potential Implications of Slim Modiolar Electrodes for Severely Malformed Cochleae: A Comparison With the Straight Array With Circumferential Electrodes

Objectives

Malformations of the inner ear account for approximately 20% of cases of congenital deafness. In current practice, straight arrays with circumferential electrodes (i.e., full-banded electrodes) are widely used in severely malformed cochleae. However, the unpredictability of the location of residual spiral ganglion neurons in such malformations argues against obligatorily using full-banded electrodes in all cases. Here, we present our experience of electrically evoked compound action potential (ECAP) and radiography-based selection of an appropriate electrode for severely malformed cochleae.

Methods

Three patients with severely malformed cochleae, showing cochlear hypoplasia type II (CH-II), incomplete partition type I (IP-I), and cochlear aplasia with a dilated vestibule (CADV), respectively, were included, and the cochlear nerve deficiency (CND) was evaluated. A full-banded electrode (CI24RE(ST)) and slim modiolar electrode (CI632) were alternately inserted to compare ECAP responses and electrode position.

Results

In patient 1 (CH-II with CND), who had initially undergone cochlear implantation (CI) using a lateral wall electrode (CI422), revision CI was performed due to incomplete insertion of CI422 and resultant unsatisfactory performance by explanting the CI422 and re-inserting the CI24RE(ST) and CI632 sequentially. Although both electrodes elicited reliable ECAP responses with correct positioning, CI24RE(ST) showed overall lower ECAP thresholds compared to CI632; thus, CI24RE(ST) was selected. In patient 2 (IP-I with CND), CI632 elicited superior ECAP responses relative to CI24RE(ST), with correct positioning of the electrode; CI632 was chosen. In patient 3 (CADV), CI632 did not elicit an ECAP response, while meaningful ECAP responses were obtained with the CI24RE(ST) array once correct positioning was achieved. All patients’ auditory performance markedly improved postoperatively.

Conclusion

The ECAP and radiography-based strategy to identify an appropriate electrode may be useful for severely malformed cochleae, leading to enhanced functional outcomes. The practice of sticking to full-banded straight electrodes may not always be optimal for IP-I and CH-II.

Factors Influencing Aberrant Facial Nerve Stimulation Following Cochlear Implantation: A Systematic Review and Meta-analysis

OBJECTIVE

The purpose of this study was to systematically evaluate the literature to evaluate the rate of and associated factors with aberrant facial nerve stimulation (AFNS) following cochlear implantation. Additionally, management strategies for AFNS were assessed.

DATA SOURCES

A systematic search was performed in PubMed, Cochrane Database of Systematic Reviews, and Web of Science to identify peer reviewed research.

STUDY SELECTION

Eligible studies were those containing peer-reviewed research in English addressing AFNS following cochlear implantation. Studies with paired data were included in the meta-analysis.

DATA EXTRACTION

Three investigators independently reviewed all articles and extracted data. Bias was assessed using the National Institutes of Health Study Quality Assessment Tool.

DATA SYNTHESIS

Thirty-seven articles were included, representing 5,694 patients. The overall reported AFNS rate was 5.6% (range, 0.68-43%). Array type demonstrated a significant association with AFNS with lateral wall electrodes having a higher odds ratio than perimodiolar electrodes (odds ratio [OR] = 3.92, 95% confidence interval [CI] 1.46-10.47, p = 0.01). CI recipients with otosclerosis were also more likely to experience AFNS compared with non-otosclerosis pathology (OR = 13.73, 95% CI 3.57-52.78, p < 0.01). Patients with cochlear malformations had an overall AFNS rate of 28% (range, 5.3-43%) and those with otosclerosis had an overall rate of 26% (range, 6.25-75%). Reprogramming with or without electrode deactivation was successful for AFNS elimination. Four patients of 3,015 required explantation.

CONCLUSION

Array type and underlying cochlear pathology are associated with AFNS and implant reprogramming is an overall successful management strategy. Further research is needed to elucidate mechanism of AFNS and develop management strategies that limit impact on hearing outcomes.

The role of preoperative imaging for auditory implants in children

&lt;b&gt;Introduction:&lt;/b&gt; Preoperative imaging, besides audiological evaluation, plays a major role in evaluation of candidacy for auditory implants, and in particular cochlear implants. It is essential to assess whether the basic criteria necessary for implantation are met. Diagnostic imaging is crucial not only in determining candidacy, but also determining the feasibility of cochlear implantation as it allow to anticipate surgical difficulties which could preclude or complicate the implantation of the device. The aim of the study is to present the protocol for the evaluation of preoperative imaging studies with particular focus on the factors potentially affecting clinical decisions in children qualified for cochlear implantation. &lt;br&gt;&lt;b&gt;Material and method:&lt;/b&gt; Preoperative imaging studies of 111 children performed prior to cochlear implantation were analyzed: high-resolution computed tomography (HRCT) of temporal bones and MRI. The assessment was made according to the presented protocol. &lt;br&gt;&lt;b&gt;Results:&lt;/b&gt; Pathologies and anomalies identified during the assessment of preoperative imaging studies significantly altered clinical decisions in 30% of patients. In the study group, in 17% of patients inner ear malformations were identified. 2.7% of children were disqualified from a cochlear implantation due to severe congenital inner ear malformations. 9% of the patients have had bacterial meningitis. In 50% of them difficulties related to complete or progressive cochlear ossification occurred. In 4.5% of patients less common surgical approaches other than mastoidectomy with a posterior tympanotomy were applied. &lt;br&gt;&lt;b&gt;Discussion:&lt;/b&gt; Preoperative imaging allow for the identification of significant pathologies and anomalies affecting qualification decisions and further treatment. HRCT and MRI are complementary to each other for preoperative imaging. The two modalities in combination allow accurate and optimal evaluation of the anatomical structures prior to implantation. Inner ear malformations and cochlear ossification following meningitis are relatively frequently encountered in children qualified for a cochlear implant.

Cochlear implantation in incomplete partition type I

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

Unilateral common cavity deformity: Recurrent meningitis due to insufficient newborn hearing screening

Insufficient newborn hearing screening may leave the other ear with undetected hearing loss. Subsequently, the missed pathology behind the impairment may have potential risk for severe infections. We describe a case of recurrent Streptococcus pneumoniae meningitis in an infant with unilateral common cavity deformity. The diagnosis of the deaf left ear was delayed due to insufficient newborn hearing screening and not until the second meningitis the pathology behind the deafness was confirmed. Subtotal petrosectomy was performed unsuccessfully and resulted in another meningitis. We highlight the importance of proper newborn hearing screening and surgical technique to treat cochlear malformations.