Cochlear implantation in incomplete partition type I

Study on characteristics of wideband acoustic immittance in patients with Inner Ear Malformations

OBJECTIVE

To compare the differences in wideband absorbance and the resonance frequency (RF) between patients with inner ear malformations and normal control, and to explore the auditory diagnostic value of wideband acoustic immittance (WAI).

METHODS

A total of 38 patients (59 ears) with enlarged vestibular aqueduct (EVA), 13 patients (14 ears) with incomplete partition type I (IP-I) and 13 patients (26 ears) with incomplete partition type II (IP-II) were included. 50 normal control (100 ears). All subjects underwent WAI tests to compare the absorbance configuration and resonance frequency.

RESULTS

All the group showed lower absorbance at ambient pressure than at peak pressure in certain frequencies under 2000Hz. Under 1000Hz, the absorbance of EVA was higher than that of other groups. The average absorbance and highest absorbance of IP-I were the lowest(P＜0.05). However, IP-II and normal group had similarity on some characteristics. The three IEM groups mainly different at low and high frequencies, but not at medium frequencies. The highest absorbance of all the groups were appeared around 3000Hz. The RF of all the groups from low to high were EVA＜IP-II＜normal control＜IP-I, and the lowest was EVA(P＜0.05).

CONCLUSION

Inner ear malformations can affect energy absorbance and RF. WAI is sensitive and non-invasive to provide useful information about inner ear status and facilitate detection of ear pathology.

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

OBJECTIVE

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

DATA SOURCES

MEDLINE, Embase, and Cochrane Library.

REVIEW METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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

OBJECTIVE

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

MATERIAL AND METHOD

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

RESULT

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

CONCLUSION

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

Recurrent bacterial meningitis caused by incomplete Type I inner ear malformation: A case report

The incidence of incomplete partition Type I inner ear malformation is very low; therefore, bacterial meningitis caused by this malformation is also rare. Here, we report a case of such a patient. This case is a young female patient, who is 7 years old, began to have recurrent headaches, and after 5 years, also began to have chest and back pain. The doctor diagnosed meningitis, and the anti-infection treatment was effective. She was followed up annually and continued to have outbreaks repeatedly for 17 years, but the cause of repeated infection was not found. After a detailed diagnosis and treatment in our hospital, the patient was finally diagnosed with incomplete partition Type I inner ear malformation, resulting in repeated bacterial meningitis. The patient recovered well after surgical treatment, and the symptoms did not recur after 1-year follow-up.

Systematic review of cochlear implantation in patients with inner ear malformations

OBJECTIVES

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

DATA SOURCES

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

REVIEW METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Pre- and post-operative imaging of cochlear implants: a pictorial review

Cochlear implants are increasingly used to treat sensorineural hearing disorders in both children and adults. Pre-operative computed tomography and magnetic resonance imaging play a pivotal role in patient selection, to rule out findings that preclude surgery or identify conditions which may have an impact on the surgical procedure. The post-operative position of the electrode array within the cochlea can be reliably identified using cone-beam computed tomography. Recognition of scalar dislocation, cochlear dislocation, electrode fold, and malposition of the electrode array may have important consequences for the patient such as revision surgery or adapted fitting.

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.