Inner Ear Malformations Research Articles

Meningitis Risk in Patients with Inner Ear Malformations after Cochlear Implants: A Systematic Review and Meta-Analysis.

The objective of this study is to determine the rate of postoperative meningitis after cochlear implantation in those with inner ear malformations (IEMs) via meta-analysis. Medline, EMBASE, and the Cochrane Library. This study was reported following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist. Proportion meta-analysis was conducted through an inverse variance random-effect model based on arcsin transformation and presented as forest plots. Quality assessment of the included studies was performed through the National Institutes of Health Quality Assessment Tool. Overall, 38 of 2966 studies met the inclusion criteria and were included in the analysis. There were 10 cases of meningitis after cochlear implantation in 1300 malformed ears. The overall rate of meningitis after cochlear implantation in IEMs was 0.12% (95% confidence interval, 0.006-0.380%; I2 = 0%). Cases occurred in incomplete partition (n = 5), Mondini deformity (n = 2), common cavity (n = 2), and enlarged internal auditory canal (n = 1). Six of 10 cases of postoperative meningitis occurred with an intraoperative cerebrospinal fluid leak. In those with IEMs, the risk of meningitis after cochlear implantation is very low.

Imaging evaluation of cerebrospinal fluid otorrhea associated with inner ear malformation in children

Objective: To explore the imaging evaluation of cerebrospinal fluid (CSF) otorrhea associated with inner ear malformation (IEM) in children. Methods: The clinical data of 28 children with CSF otorrhea associated with IEM confirmed by surgical exploration in Beijing Children's Hospital, from Nov, 2016 to Jan, 2021, were analyzed retrospectively,including 16 boys and 12 girls, aged from 8-month to 15-year and 8-month old, with a median age of 4-year old. The shapes of stapes were observed during the exploration surgery, and the imaging features of temporal bone high resolution CT(HRCT) and inner ear MRI pre- and post-operation were analyzed. Results: In 28 children with CSF otorrhea, 89.3%(25/28) had stapes footplates defect during exploration. Preoperative CT showed indirect signs such as IEM, tympanic membrane bulging, soft tissue in the tympanum and mastoid cavity. IEM included four kinds: incomplete partition type I (IP-Ⅰ), common cavity (CC), incomplete partition type Ⅱ (IP-Ⅱ), and cochlear aplasia (CA); 100%(28/28) presented with vestibule dilation; 85.7%(24/28) with a defect in the lamina cribrosa of the internal auditory canal. The direct diagnostic sign of CSF otorrrhea could be seen in 73.9%(17/23) pre-operative MRI: two T2-weighted hyperintense signals between vestibule and middle ear cavity were connected by slightly lower or mixed intense T2-weighted signals, and obvious in the coronal-plane; 100%(23/23) hyperintense T2-weighted signals in the tympanum connected with those in the Eustachian tube.In post-operative CT, the soft tissues in the tympanum and mastoid cavity decreased or disappeared as early as one week. In post-operative MRI, the hyperintense T2-weighted signals of tympanum and mastoid decreased or disappeared in 3 days to 1 month,soft tissues tamponade with moderate intense T2-weighted signal were seen in the vestibule in 1-4 months. Conclusions: IP-Ⅰ, CC, IP-Ⅱ and CA with dilated vestibule can lead to CSF otorrhea. Combined with special medical history, T2-weighted signal of inner ear MRI can provide diagnostic basie for most children with IEM and CSF otorrhea.HRCT and MRI of inner ear can also be used to evaluate the effect of surgery.

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 12months and 15years. 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 1year and at 2years (1year CAP score p value < 0.001, 2year CAP score p value 0.002 and 1year SIR score, p value < 0.001, 2year SIR score, p value 0.013). There was progressive improvement in the scores (of both groups) at the 2year mark, compared to 1year 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.

The effect of cochlear size on electrically evoked auditory brainstem responses in deaf children.

To investigate the relationship between auditory pathway function and cochlear size in deaf children with a radiologically normal inner ear or Mondini malformation. Thirty-five deaf children without inner ear malformations (IEMs) and forty cases with Mondini malformation were included in this study. The electrically evoked auditory brainstem responses (EABRs) evoked by electrical stimulation at the round window niche (RWN) and round window membrane (RWM) were recorded during cochlear implantation (CI) surgery. The anatomical parameters of the cochlea were assessed by high-resolution computed tomography and OTOPLAN 3-D construction software. Correlations between EABRs and cochlear sizes were analyzed. The EABR thresholds and/or latencies were negatively correlated with the basal cochlear diameter, cochlear width and/or cochlear duct length in both patients without IEMs and those with Mondini malformation. The physiological function of the peripheral auditory system depends on the anatomical structure of the cochlea to an extent. A larger cochlear size appears to be associated with better auditory conduction function. Our findings may be beneficial to selection of the proper electrode type and prediction of postoperative auditory rehabilitation. Level 4.

Anatomical and clinical aspects and outcomes of bilateral cochlear implantation in cochlear hypoplasia type IV - a case report

Cochlear hypoplasia is a congenital inner ear malformation (IEM) characterized by a reduced external cochlear dimension, usually accompanied by an abnormal internal architecture. Type IV cochlear hypoplasia is a cochlea with hypoplastic middle and apical turns. It may occur along with dislocation of the facial nerve, associated with semicircular abnormalities, less clearly marked promontory, or stapedial fixation. Such patients can present a broad spectrum of audiological test results, from sensorineural or mixed mild or profound hearing loss. The above anatomical changes may be responsible for intraoperative difficulties during cochlear implantation. In the studied case, a 6-month-old patient was diagnosed with an inner ear malformation - cochlear hypoplasia type IV on both sides. Computed tomography with multiplanar and 3D reconstruction was performed to analyze the middle and inner ear anatomy in detail. Both types of imaging reconstruction helped decide which cochlear implant electrode to choose. Perimodiolar-positioned cochlear implant electrode was found to be the most suitable choice. The patient underwent sequential bilateral cochlear implantation with expected incomplete electrode array insertion on both sides. First repeatable auditory responses were observed two months after the second implant activation. Good parental cooperation with therapists and adequately defined developmental goals in the presented patient allowed the multidisciplinary team to take advantage of the child's intellectual abilities and choose the suitable communication method; however, the patient's auditory responses were obtained slowly. The final auditory results cannot be predicted in inner ear malformations due to abnormal anatomical structure and, thus, heterogeneous innervation within the deformed cochlea. The programming of the sound processor must be individual in each case, based on the child's behavior observation and, if possible, objective test results. Patients with cochlear malformations usually require higher stimulation intensities to obtain sound sensations than patients with a typical cochlear structure.

Method to estimate the basal turn length in inner ear malformation types

The mathematical equations to estimate cochlear duct length (CDL) using cochlear parameters such as basal turn diameter (A-value) and width (B-value) are currently applied for cochleae with two and a half turns of normal development. Most of the inner ear malformation (IEM) types have either less than two and a half cochlear turns or have a cystic apex, making the current available CDL equations unsuitable for cochleae with abnormal anatomies. Therefore, this study aimed to estimate the basal turn length (BTL) from the cochlear parameters of different anatomical types, including normal anatomy; enlarged vestibular aqueduct; incomplete partition types I, II, and III; and cochlear hypoplasia. The lateral wall was manually tracked for 360° of the angular depth, along with the A and B values in the oblique coronal view for all anatomical types. A strong positive linear correlation was observed between BTL and the A- (r2 = 0.74) and B-values (r2 = 0.84). The multiple linear regression model to predict the BTL from the A-and B-values resulted in the following equation (estimated BTL = [A × 1.04] + [B × 1.89] − 0.92). The manually measured and estimated BTL differed by 1.12%. The proposed equation could be beneficial in adequately selecting an electrode that covers the basal turn in deformed cochleae.

Electrically Evoked Auditory Brainstem Responses in Children Fitted with Hearing Aids Prior to Cochlear Implantation.

This study investigates the effect of hearing aid use on the peripheral auditory pathways in children with sensorineural hearing loss prior to cochlear implantation, as revealed by the electrically evoked auditory brainstem response (EABR). Forty children with hearing aids were recruited. Half of them had normal inner ear structures and the other half had inner ear malformations (IEMs). The EABR was evoked by electrically stimulating the round window niche (RWN) and round window membrane (RWM) during the cochlear implantation operation. The onset age of hearing aid use was significantly correlated with the peak latencies, but not amplitudes, of the wave III (eIII) and wave V (eV). Higher EABR thresholds were found for RWN stimulation than for RWM stimulation and in the children with IEMs than in those without IEMs. Our study provides neurophysiological evidence that earlier use of hearing aids may ameliorate physiological functions of the peripheral auditory pathway in children with and without IEMs. The EABR evoked by the electrical stimulation at RWM is more sensitive compared with that at RWN for evaluating functions of the auditory conduction pathway.

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.

A novel three-step process for the identification of inner ear malformation types.

We hypothesize that visualizing inner-ear systematically in both cochlear view (oblique coronal plane) and in mid-modiolar section (axial plane) and following three sequential steps simplifies, identification of inner-ear malformation types. Pre-operative computer-tomography (CT) scans of temporal bones of 112 ears with various inner ear malformation (IEM) types were taken for analysis. Images were analyzed using DICOM viewers, 3D slicer, and OTOPLAN®. The inner-ear was captured in the oblique-coronal plane for the measurement of length and width of cochlear basal turn which is also called as A-, and B-values respectively (Step 1). In the same plane, the angular-turns of lateral-wall (LW) of cochlear basal turn were measured (Step 2). As Step 3, the mid-modiolar section of inner ear was captured in the axial plane by following the A-value and perpendicular to cochlear view. From the mid-modiolar section, the outer-contour of inner ear was captured manually by following contrasting gray area between fluid filled and bony promontory and was compared to known resembling objects to identify IEM types (Step 3). Following reference values have emerged from our analysis: A-, and B-values (Step 1) on average are >8 mm and >5.5 mm respectively, in normal cochleae (NA), enlarged vestibular aqueduct syndrome (EVAS), incomplete partition (IP) type-I and -II, whereas it is <8 mm and <5.5 mm respectively, in IP type-III and cochlear hypoplasia (CH). Angular-turn of LW is consistently observed in cochlear basal turn (Step 2), is 540° in NA and EVAS, 450° in IP-II, and 360° in IP types I & III. In subjects with CH type, angular-turn of LW is either 360° or 450° or 540°. In true mid-modiolar section, outer-contour of inner-ear (Step-3), other than in CH and cystic inner-ear malformations, resembles recognizable shapes of known objects. Absence of EVA is an additional characteristic that confirms diagnosis of CH when the A-, B-values, and angular-turn of LW can be similar to other anatomical types. Drawing a straight line along posterior edge of internal auditory canal (IAC) in axial view can differentiate a true common cavity (CC) from cochlear aplasia-vestibular cavity (VC). Three-step process proposed in this study captures inner-ear in cochlear view as well in mid-modiolar sections visualizing key features of inner-ear in identification of IEM types. Level 1.

Cerebrospinal Fluid Gusher in Cochlear Implantation and Its Association with Inner-Ear Malformations.

It is aimed to investigate the incidence of cerebrospinal fluid gusher in cochlear implantation and the association between cerebrospinal fluid gusher and inner-ear malformations in adult and pediatric patients. A retrospective case review of 1025 primary cochlear implantation procedures was performed. Patients with inner-ear malformation or cerebrospinal fluid gusher during primary cochlear implantation were included and divided into 2 groups according to age: pediatric and adult groups. The incidence of inner-ear malformation was 4.19% (17/405) and 7.6% (47/620) in the adult and pediatric groups, respectively. There was a significant difference in the incidence of inner-ear malformation in the pediatric group. The incidence of cerebrospinal fluid gusher was 0.9% (4/405) and 4.1% (26/620) in the adult and pediatric groups, respectively. There was a significant difference in the incidence of gusher between the adult and pediatric groups. The incidence of a cerebrospinal fluid gusher is higher in the pediatric group, compared to adults due to a higher rate of inner-ear malformation. Inner-ear malformation poses a risk factor for cerebrospinal fluid gusher.

Systematic review of cochlear implantation in patients with inner ear malformations.

ObjectivesTo 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 sourcesPubMed, Science Direct, Web of Science, Scopus, and EMBASE databases.Review methodsAfter 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.ResultsIEMs 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.ConclusionsCochlear 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.

Volumetry improves the assessment of the vestibular aqueduct size in inner ear malformation

ObjectivesEnlarged vestibular aqueduct (EVA) is a common finding associated with inner ear malformations (IEM). However, uniform radiologic definitions for EVA are missing and various 2D-measurement methods to define EVA have been reported. This study evaluates VA volume in different types of IEM and compares 3D-reconstructed VA volume to 2D-measurements.MethodsA total of 98 high-resolution CT (HRCT) data sets from temporal bones were analyzed (56 with IEM; [cochlear hypoplasia (CH; n = 18), incomplete partition type I (IPI; n = 12) and type II (IPII; n = 11) and EVA (n = 15)]; 42 controls). VA diameter was measured in axial images. VA volume was analyzed by software-based, semi-automatic segmentation and 3D-reconstruction. Differences in VA volume between the groups and associations between VA volume and VA diameter were assessed. Inter-rater-reliability (IRR) was assessed using the intra-class-correlation-coefficient (ICC).ResultsLarger VA volumes were found in IEM compared to controls. Significant differences in VA volume between patients with EVA and controls (p < 0.001) as well as between IPII and controls (p < 0.001) were found. VA diameter at the midpoint (VA midpoint) and at the operculum (VA operculum) correlated to VA volume in IPI (VA midpoint: r = 0.78, VA operculum: r = 0.91), in CH (VA midpoint: r = 0.59, VA operculum: r = 0.61), in EVA (VA midpoint: r = 0.55, VA operculum: r = 0.66) and in controls (VA midpoint: r = 0.36, VA operculum: r = 0.42). The highest IRR was found for VA volume (ICC = 0.90).ConclusionsThe VA diameter may be an insufficient estimate of VA volume, since (1) measurement of VA diameter does not reliably correlate with VA volume and (2) VA diameter shows a lower IRR than VA volume. 3D-reconstruction and VA volumetry may add information in diagnosing EVA in cases with or without additional IEM.

Internal auditory canal volume in normal and malformed inner ears

PurposeA narrow bony internal auditory canal (IAC) may be associated with a hypoplastic cochlear nerve and poorer hearing performances after cochlear implantation. However, definitions for a narrow IAC vary widely and commonly, qualitative grading or two-dimensional measures are used to characterize a narrow IAC. We aimed to refine the definition of a narrow IAC by determining IAC volume in both control patients and patients with inner ear malformations (IEMs).MethodsIn this multicentric study, we included high-resolution CT (HRCT) scans of 128 temporal bones (85 with IEMs: cochlear aplasia, n = 11; common cavity, n = 2; cochlear hypoplasia type, n = 19; incomplete partition type I/III, n = 8/8; Mondini malformation, n = 16; enlarged vestibular aqueduct syndrome, n = 19; 45 controls). The IAC diameter was measured in the axial plane and the IAC volume was measured by semi-automatic segmentation and three-dimensional reconstruction.ResultsIn controls, the mean IAC diameter was 5.5 mm (SD 1.1 mm) and the mean IAC volume was 175.3 mm3 (SD 52.6 mm3). Statistically significant differences in IAC volumes were found in cochlear aplasia (68.3 mm3, p < 0.0001), IPI (107.4 mm3, p = 0.04), and IPIII (277.5 mm3, p = 0.0004 mm3). Inter-rater reliability was higher in IAC volume than in IAC diameter (intraclass correlation coefficient 0.92 vs. 0.77).ConclusionsVolumetric measurement of IAC in cases of IEMs reduces measurement variability and may add to classifying IEMs. Since a hypoplastic IAC can be associated with a hypoplastic cochlear nerve and sensorineural hearing loss, radiologic assessment of the IAC is crucial in patients with severe sensorineural hearing loss undergoing cochlear implantation.

Surgical methods of cerebrospinal fluid otorhinorrhea due to inner ear malformation in children

Objective:To discuss the application of two surgical methods, trans-mastoid approach and trans-canal endoscopic approach, in the treatment of CerebroSpinal Fluid（CSF） otorhinorrhea due to inner ear malformation（IEM） in children. Methods:Children with CSF otorhinorrhea due to IEM, from July 2015 to Jan 2021, in ENT department, Beijing Children's Hospital were retrospectively analyzed, and the clinical data, surgical methods, complications, recurrence and follow-up were recorded. Results:30 children with CSF otorhinorrhea due to IEM were included. Half of them had a history of otorhinorrhea, and 53.3% of them were diagnosed as cerebrospinal fluid（CSF） otorrhea at the first onset Unilateral and bilateral IEM were 22 cases and 8 cases respectively. All unilateral IEM children had secondary infections such as meningitis or/and pneumonia, and 9.1% had cochlear implantation（CI） due to deafness after meningitis. 87.5% bilateral IEM children had CI due to profound/severe hearing loss. 96.7% CSF otorhinorrhea were unilateral, there was no relationship between CSF otorhinorrhea and the malformation side or the time of CI surgery. Trans-mastoid approach was used in 14 cases, usually involving CI or other operations; and endoscopic approach in 16 cases. The age of trans-mastoid group was younger than that of endoscopic group. No recurrence and complications occured in the trans-mastoid group. In the endoscopic group, 2 cases recurred; 3 cases had complications（2 with temporary facial paralysis and 1 with labyrinth and intracranial pneumatosis）. Except one case lost, the others were followed up for 1.2-6.7 years, and no recurrence of pneumonia, meningitis and CSF otorhinorrhea happened. Conclusion:Unilateral IEM usually leads to meningitis or/and pneumonia, and bilateral IEM requires CI. Both trans-mastoid and trans-canal endoscopic approach were effective for CSF otorrhea repair. Trans-mastoid approach is suitable for those who need mastoid exploration, CI or combined with other operations. Trans-canal endoscopic approach was choosed when fistula was confined to the tympanum and ear canal diameter was wide enough.

Cochlear and Vestibular Volumes in Inner Ear Malformations.

Retrospective cohort. Tertiary academic center. High-resolution CT scans of 115 temporal bones (70 with IEM; cochlear hypoplasia [CH]; n = 19), incomplete partition (IP) Types I and III (n = 16), IP Type II with an enlarged vestibular aqueduct (Mondini malformation; n = 16), enlarged vestibular aqueduct syndrome (n = 19), and 45 controls. Volumetry by software-based, semiautomatic segmentation, and 3D reconstruction. Differences in volumes among IEM and between IEM types and controls; interrater reliability. Compared with controls (mean volume, 78.0 mm3), only CH showed a significantly different cochlear volume (mean volume, 30.2 mm3; p < 0.0001) among all types of IEM. A cutoff value of 60 mm3 separated 100% of CH cases from controls. Compared with controls, significantly larger vestibular system volumes were found in Mondini malformation (mean difference, 22.9 mm3; p = 0.009) and IP (mean difference, 24.1 mm3; p = 0.005). In contrast, CH showed a significantly smaller vestibular system volume (mean difference, 41.1 mm3; p < 0.0001). A good interrater reliability was found for all three-dimensional measurements (ICC = 0.86-0.91). Quantitative reference values for IEM obtained in this study were in line with existing qualitative diagnostic characteristics. A cutoff value less than 60 mm3 may indicate an abnormally small cochlea. Normal reference values for volumes of the cochlea and vestibular system may aid in diagnosing IEM.

Inner Ear Malformations in Cochlear Implantation Candidates at Mother and Child Hospital of Bingerville (Côte d’Ivoire)

Abstract Objective The aim of this study was to determine the prevalence and types of inner ear and/or cochlear nerve anomalies in children who are candidates for cochlear implantation. Methods This was a descriptive cross-sectional study with a retrospective review of medical and imaging records performed in a tertiary care children's hospital. All cochlear implants candidates under 15 years old with imaging assessment between January 2019 and December 2021 were concerned. The studied parameters were reason for consultation, risks factors, inner ear malformations (IEMs) classified and stratified by sensorineural hearing loss (SNHL) degree, gender, and age at diagnosis. Results In total, 81 children (162 ears) were included in the study. Abnormalities of the inner ear were found in nine children representing a prevalence of 11.1%. These children were aged between 2 and 14 years. The average age at diagnosis of SNHL was 3.5 years. Seven children had bilateral anomalies and two unilateral anomalies, that is, 16 ears presenting 40 malformations. These included 1 complete labyrinthine aplasia (2.5%), 12 cochlear malformations (30%), 1 common cavity (2.5%), 17 vestibular/squamous cell carcinoma (SCC) malformations (42.5%), and 5 internal auditory canal malformations (12.5%). Three ear out of 16 with abnormalities demonstrated a deficient cochlear nerve. There was an association between IEMs and profound deafness, and age at diagnosis of SNHL less than 2 years. Conclusion This study shows that 11.1% of children with profound deafness have IEMs. SCC malformations and cochlear hypoplasia were the most common. A precise description of these malformations during the imaging assessment is particularly useful for cochlear implantation to better plan this surgery.

Hearing-related quality of life assessment of pediatric cochlear implant users with inner ear malformations

ObjectivesTo assess the quality of life (QoL) in child and adolescent cochlear implant users with inner ear malformations (IEM) and to compare their outcomes to their cochlear implant using peers with normal inner ear structures. MethodsThe present sample consisted of 100 children (45 with IEM, 55 without IEM) and 100 adolescents (46 with IEM, 54 without IEM). The following QoL questionnaires were used to assess the hearing-related QoL: The Hearing Environments and Reflection on Quality of Life 26 (HEAR-QL-26 for children between 7 and 12 years of age) and HEAR-QL-28 (for adolescents between 13 and 18 years of age). Both questionnaires were based on a 5-points Likert scale from 0 to 4, with higher scores indicating a better perception of QoL. The scores were converted to percentage values (never = 100, almost never = 75, sometimes = 50, often = 25, almost always = 0). ResultsFor the patients with IEM, mean scores from the HEAR-QL-26 and HEAR-QL-28 were 50.4 (SD = 18.9) and 54.5 (SD = 19.6), respectively. For the patients without IEM, mean scores from the HEAR-QL-26 and HEAR-QL-28 were 72.7 (SD = 18.0) and 65.0 (SD = 19.1), respectively. For both child and adolescent subgroups, statistically significant differences were observed between QoL scores from patients with and without IEM (p < 0.001). There were no statistically significant effects of the malformation type on the QoL findings (p ≥ 0.05). ConclusionChild and adolescent cochlear implant users with IEM had significantly lower scores on validated HEAR-QL versions in comparison to their implanted peers without IEM.

Effect of inner ear malformations on intraoperative ECAP thresholds and postoperative auditory performance.

ObjectivesThis study sought to characterize the influence of inner ear malformations (IEMs) on intraoperative electrically evoked compound action potential (ECAP) and auditory performance to better understand the underlying pathophysiology related to variabilities in cochlear implant (CI) outcomes that individuals with malformed cochlea may present.MethodsThe medical records of 222 ears implanted with Cochlear Nucleus CI were reviewed. Of the total, 64 ears had radiologic evidence of IEMs, and 158 ears were normal. Individuals with IEMs were grouped based on the severity of anomalies; 38 had mild IEMs (e.g., enlarged vestibular aqueduct, incomplete partition type II, etc.) and 26 had severe IEMs (e.g., cochlear nerve hypoplasia, common cavity, etc.). Intraoperative ECAP thresholds obtained via neural response telemetry (NRT) and the categories of auditory performance (CAP) scores measured at 12 months postoperative were compared and correlated.ResultsAbsent ECAP responses were more apparent in the IEM group. ECAP thresholds were significantly elevated in the severe IEM group, while the mild IEM group had ECAP thresholds comparable to the normal group. The mild IEM group achieved CAP scores similar to the normal control. Patients in the severe IEM group showed significantly lower CAP scores at 12 months postoperative. Significant negative relationships existed between ECAP thresholds and CAP scores obtained from all subjects.ConclusionMeasurable ECAP responses and NRT thresholds varied across groups. The inverse relationship between NRT thresholds and CAP scores may suggest that electrophysiological responses measured during surgery may potentially be indicative of postoperative performance in our CI population.Level of Evidence2b.

Electrically evoked auditory brainstem responses in deaf patients with Mondini malformation during cochlear implantation.

To investigate the auditory pathway functions in deaf patients with Mondini malformation using the electrically evoked auditory brainstem response (EABR) during cochlear implantation (CI). A total of 58 patients with severe to profound sensorineural hearing loss (SNHL) were included in this study. Of these patients, 27 cases had Mondini malformation and 31 control cases had no inner ear malformations (IEMs). Intraoperative EABRs evoked by electrical stimulation at the round window niche (RWN) and round window membrane (RWM) were recorded. Patients with Mondini malformation showed significantly lower EABR extraction rates than those with no IEMs did. However, for patients who showed EABRs, no significant difference in EABR thresholds, wave III (eIII) latencies, wave V (eV) latencies or eIII-eV latency intervals was found between two groups. The physiological functions of the peripheral auditory system in patients with Mondini malformation may divide into opposite extremes, as revealed by a robust EABR and the absence of the EABR, respectively. The auditory conduction function should be objectively and individually evaluated for patients with Mondini malformation by the EABR.

Pediatric cochlear implant fitting parameters in inner ear malformation: Is it same with normal cochlea?

ObjectivesThe aim was to evaluate the cochlear implant (CI) mapping parameters of CI users with inner ear malformation (IEM) and to reveal the changes in parameters over time. MethodsIn total, 118 CI users were included with 127 ears (68-IEM; 59-normal cochlear anatomy) in present retrospective study. The impedance measurements, thresholds levels-THR, most comfortable levels- MCL, pulse width-PW and rate values were analyzed in both IEM and control group at the initial activation, 6th,12th and 24th months postoperatively. ResultsThere were statistically significant differences in impedance measurements in several time points. And also, there was a remarkable difference in THR & MCL and PW values between IEM and control groups in all time points (p < 0.05). THR & MCL levels and PW values increased significantly between all time periods in both groups (p < 0,008) and values of parameters in IEM-group were higher than those of control group. When comparing rates, statistically significant difference was observed only at the initial activation in both within (p < 0.001) and between groups (p = 0.03). ConclusionPediatric CI users with IEM need individual changes in fitting parameters. More frequent map sessions should be planned as they require more PW, THR and MCL increase over time. The increase rate differs between IEM subgroups depending on the deviation of malformation from the normal cochlear anatomy. This study is the first to in its attempt to reveal the mapping characteristics and long-term changes in pediatric CI users with different IEM subgroups.