Cochlear Malformation Research Articles

Identifying DNA Variants in a Turkish Cohort with Inner Ear Anomalies.

To determine the genetic causes of sensorineural hearing loss (SNHL) associated with inner ear anomalies, 11 unrelated Turkish individuals diagnosed with SNHL and an inner ear anomaly using temporal bone computed tomography and inner ear magnetic resonance imaging underwent exome or whole genome sequencing to identify underlying genetic defects. None of the individuals was diagnosed with a recognized syndrome. Four of the 11 probands were homozygous for SLC26A4 variants, c.283G>A, c.845G>A, c.1061T>C, and c.1198delT. Another proband was homozygous for a TECTA variant, c.4163G>A. Patients with variants of the SLC26A4 gene had bilateral enlarged vestibular aqueduct, bilateral incomplete partition type 2 anomaly, bilateral hypoplastic cochlea and bilateral enlarged vestibular aqueduct plus hypoplastic cochlea anomaly. Patients with the variant TECTA gene had bilateral hypoplastic cochlea. This study identified variants of SLC26A4 in 36% of probands with inner ear anomalies. While we identified a variant of the TECTA gene in a proband with cochlear hypoplasia, further studies are needed to see if TECTA variants can cause cochlear malformations.

Genomic and phenotypic landscapes of X-linked hereditary hearing loss in the Chinese population

BackgroundHearing loss (HL) is the most common sensory birth deficit worldwide, with causative variants in more than 150 genes. However, the etiological contribution and clinical manifestations of X-linked inheritance in HL remain unclear within the Chinese HL population. In this study, we focused on X-linked hereditary HL and aimed to assess its contribution to hereditary HL and identify the genotype–phenotype relationship.MethodsWe performed a molecular epidemiological investigation of X-linked hereditary HL based on next-generation sequencing and third-generation sequencing in 3646 unrelated patients with HL. We also discussed the clinical features associated with X-linked non-syndromic HL-related genes based on a review of the literature.ResultsWe obtained a diagnostic rate of 52.72% (1922/3646) among our patients; the aggregate contribution of HL caused by genes on the X chromosome in this cohort was ~ 1.14% (22/1922), and POU3F4 variants caused ~ 59% (13/22) of these cases. We found that X-linked HL was congenital or began during childhood in all cases, with representative audiological profiles or typical cochlear malformations in certain genes. Genotypic and phenotypic analyses showed that causative variants in PRPS1 and AIFM1 were mainly of the missense type, suggesting that phenotypic variability was correlated with the different effects that the replaced residues exert on structure and function. Variations in SMPX causing truncation of the protein product were associated with DFNX4, which resulted in typical audiological profiles before and after the age of 10 years, whereas nontruncated proteins typically led to distal myopathy. No phenotypic differences were identified in patients carrying POU3F4 or COL4A6 variants.ConclusionsOur work constitutes a preliminary evaluation of the molecular contribution of X-linked genes in heritable HL (~ 1.14%). The 15 novel variants reported here expand the mutational spectrum of these genes. Analysis of the genotype–phenotype relationship is valuable for X-linked HL precise diagnostics and genetic counseling. Elucidation of the pathogenic mechanisms and audiological profiles of HL can also guide choices regarding treatment modalities.

Cochlear reimplantation outcomes over 20 years: Expertise in reimplantation surgery and auditory-speech rehabilitation

ObjectivesThe aim of this study was to present an institution's experience with cochlear reimplantation (CRI), to assess surgical challenges and post-operative outcomes and to increase the success rate of CRI. Study designRetrospective single-institution study. SettingTertiary medical center. MethodsWe retrospectively evaluated data from 76 reimplantation cases treated in a tertiary center between 2001 and 2022. Clinical features including etiology of hearing loss, type of failure, surgical issues, and auditory speech performance were analyzed. Categorical Auditory Performance (CAP) and Speech Intelligibility Rating (SIR) scores were used to evaluate pre- and post-CRI outcomes. ResultsThe CRI population comprises of 7 patients from our institute,69 referred patients from other centers. Device failure was the most common reason (68/76, 89.5 %) for CRI; in addition, there were 7 medical failures and 1 had both soft device failure. Medical failures included flap rupture and device extrusion, magnet migration, auditory neuropathy, leukoencephalopathy, foreign-body residue and meningitis. In 21/76 patients, the electrode technology was upgraded. The mean time to failure was 0.58–13 years, with a mean of 4.97 years. The mean (± SD) CAP and SIR scores before and after CRI were 5.2 ± 1.2 versus 5.5 ± 1.1 and 3.4 ± 1.1 versus 3.5 ± 1.1, respectively. Performance was poor in six patients with severe cochlear malformation, auditory nerve dysplasia, leukoencephalopathy, and epilepsy. ConclusionCRI surgery is a challenging but relatively safe procedure, and most reimplanted patients experience favorable postoperative outcomes. Medical complications and intracochlear damage are the main causes of poor postoperative results. Therefore, adequate preoperative preparation and atraumatic CRI should be carried out for optimal results.

Human Organoids for Rapid Validation of Gene Variants Linked to Cochlear Malformations.

Developmental anomalies of the hearing organ, the cochlea, are diagnosed in approximately one-fourth of individuals with congenital deafness. Most patients with cochlear malformations remain etiologically undiagnosed due to insufficient knowledge about underlying genes or the inability to make conclusive interpretations of identified genetic variants. We used exome sequencing for genetic evaluation of hearing loss associated with cochlear malformations in three probands from unrelated families. We subsequently generated monoclonal induced pluripotent stem cell (iPSC) lines, bearing patient-specific knockins and knockouts using CRISPR/Cas9 to assess pathogenicity of candidate variants. We detected FGF3 (p.Arg165Gly) and GREB1L (p.Cys186Arg), variants of uncertain significance in two recognized genes for deafness, and PBXIP1(p.Trp574*) in a candidate gene. Upon differentiation of iPSCs towards inner ear organoids, we observed significant developmental aberrations in knockout lines compared to their isogenic controls. Patient-specific single nucleotide variants (SNVs) showed similar abnormalities as the knockout lines, functionally supporting their causality in the observed phenotype. Therefore, we present human inner ear organoids as a tool to rapidly validate the pathogenicity of DNA variants associated with cochlear malformations.

Clinical features of congenitally enlarged bony portion of Eustachian tube

Objective:To investigate the clinical features of patients with congenitally enlarged bony portions of the Eustachian tube（ET）. Methods:The medical history, physical examination, hearing test, temporal bone high resolution computed tomography（HRCT） of six patients（nine ears） with congenitally enlarged bony portion of the ET were retrospectively analyzed. Results:Four patients were men and two were women. The minimum, maximum, and average ages were 5, 21, and（14.7±6.4） years, respectively. Three malformations were bilateral and three were left-sided. Three ears had conductive hearing loss（average bone and air conduction thresholds were 13.7 dB and 71.3 dB）, three had mixed hearing loss（average bone and air conduction thresholds were 27.7 dB and 83.7 dB）, and one had extremely severe sensorineural hearing loss. The average maximum length and width of the enlarged bony ET on temporal bone HRCT were（22.61±2.94） mm and（6.50±2.33） mm, respectively. The enlargement was combined with an external auditory canal malformation in six ears, narrow tympanic cavity in six, tympanic antrum malformation in five, ossicular chain malformation in seven, cochlear malformation in six, helicotrema malformation in three, vestibule widening in two, semicircular canal malformation in three, vestibular window malformation in six, facial nerve abnormality in five, internal auditory meatus malformation in two, low middle cranial fossa in eight, and severe internal carotid artery malformation in one. Conclusion:Bony ET enlargement is a rare congenital middle ear malformation which could combined with other ear malformations. Patients can have no ET dysfunction but different patterns of hearing loss. The defect is usually found unintentionally during imaging, and the HRCT of temporal bone is significant.

Aberrant Course of the Intratemporal Facial Nerve in Children with Congenital Hearing Loss.

Congenital facial nerve (FN) malformations are uncommon. Our aim is to determine the clinical and radiological features of FN malformations along with the associated cochlear and vestibular malformations. We conducted a retrospective study including children with a profound sensorineural hearing loss who were candidates for cochlear implantation. We evaluated the presence of FN malformations through temporal bone computed tomography scan and magnetic resonance imaging. We recorded an aberrant FN course in five out of 165 patients in a total of 9 ears. They consisted of a bifurcation of the mastoid segment, an anterior or posterior displacement of the labyrinthine segment and a hypoplasia of the geniculate ganglion. Associated inner ear malformations included vestibular aqueduct dilation, cochlear hypoplasia and total labyrinthine aplasia. We noted a bilateral agenesis of the cochlear nerve in three patients. Facial nerve malformations should be suspected in patients presenting a congenital hearing loss especially in association with other temporal bone malformations. Their pre-operative discovery is helpful in planning the surgical procedure.

Electrically evoked auditory brainstem responses in deaf children with cochlear nerve canal stenosis

Background Deaf children with cochlear nerve canal stenosis (CNCs) are always considered poor candidates for cochlear implantation. Objectives To investigate the function of the peripheral auditory pathway in deaf children with CNCs, as revealed by the electrically evoked auditory brainstem response (EABR), and postoperative cochlear implants (CIs) outcomes. Materials and Methods Thirteen children with CNCs and 13 children with no inner ear malformations (IEMs) who received CIs were recruited. The EABR evoked by electrical stimulation from the CI electrode was recorded. Postoperative CI outcomes were assessed using Categories of Auditory Performance (CAP) and Speech Intelligibility Rate (SIR). Results Compared with children with no IEMs, children with CNCs showed lower EABR extraction rates, higher thresholds, a longer wave V (eV) latency and lower CAP and SIR scores. The auditory and speech performance was positively correlated with the diameter of the cochlear nerve canal and the number of channels showing wave III (eIII) and eV in children with CNCs. Conclusions and Significance The physiological function of the peripheral auditory pathway in children with CNCs is poorer than that in children with no IEMs. Postoperative auditory and speech abilities may depend on the severity of cochlear nerve malformation and auditory conduction function.

A Case Report of Cochlear Malformations: A Rare Case of Unilateral Type I Incomplete Partition with Cochlear Nerve Aplasia and Contralateral Common Cavity Malformation with Normal Vestibulocochlear Nerve

A Case Report of Cochlear Malformations: A Rare Case of Unilateral Type I Incomplete Partition with Cochlear Nerve Aplasia and Contralateral Common Cavity Malformation with Normal Vestibulocochlear Nerve

Sensorineural Hearing Loss and Cochleovestibular Malformations in Children in Côte d’Ivoire

Objective: to find the distribution of various malformations and to report the clinical features of commonly encountered IEMs in our practice. Methods: This was a retrospective cross-sectional study, over a period of 14 months (January 2019 to March 2020), in the ENT departments of University Hospitals and the Mother and Child Hospital in Bingerville. All patients, aged up 15 years with computed tomography and/or MRI available, who had a cochleovestibular malformation and sensorineural or predominantly sensorineural mixed hearing loss confirmed were included. Results: The prevalence of sensorineural hearing loss related to cochleovestibular malformations was 3.75% (6 cases out of 160 patients). Patients ranged in age from 2 to 14 years. The diagnosis was made before the age of 3.5 years in 5/6 cases. The sex ratio was 1. Language delay was noted in 5/6 cases. No contributing risk factors were identified. All patients had profound and bilateral hearing loss. Associated malformations were present in 2/6 cases. The most common abnormalities were semicircular canal hypoplasia, internal auditory canal abnormalities and cochlear malformations. There was an association between sensorineural hearing loss linked to malformation and the profound degree of hearing loss. Conclusion: Sensorineural deafness linked to cochleovestibular malformations in children appears to be uncommon. However, they are associated with a risk of profound sensorineural hearing loss. It is therefore important, in the face of any sensorineural hearing loss in the child, to systematically carry out an imaging assessment, even in our low income’s countries.

Hearing Performance in Cochlear Implant Users Who Have Facial Nerve Stimulation.

Introduction Facial nerve stimulation (FNS) is a complication in cochlear implant (CI) when the electrical current escapes from the cochlea to the nearby facial nerve. Different management to reduce its effects are available, although changes might result in a less-than-ideal fitting for the CI user, eventually reducing speech perception. Objective To verify the etiologies that cause FNS, to identify strategies in managing FNS, and to evaluate speech recognition in patients who present FNS. Methods Retrospective study approved by the Ethical Board of the Institution. From the files of a CI group, patients who were identified with FNS either during surgery or at any time postoperatively were selected. Data collection included: CI manufacturer, electrode array type, age at implantation, etiology of hearing loss, FNS identification date, number of electrodes that generated FNS, FNS management actions, and speech recognition in quiet and in noise. Results Data were collected from 7 children and 25 adults. Etiologies that cause FNS were cochlear malformation, head trauma, meningitis, and otosclerosis; the main actions included decrease in the stimulation levels followed by the deactivation of electrodes. Average speech recognition in quiet before FNS was 86% and 80% after in patients who were able to accomplish the test. However, there was great variability, ranging from 0% in quiet to 90% of speech recognition in noise. Conclusion Etiologies that cause FNS are related to cochlear morphology alterations. Facial nerve stimulation can be solved using speech processor programming parameters; however, it is not possible to predict outcomes, since results depend on other variables.

Utility of deep learning for the diagnosis of cochlear malformation on temporal bone CT.

Diagnosis of cochlear malformation on temporal bone CT images is often difficult. Our aim was to assess the utility of deep learning analysis in diagnosing cochlear malformation on temporal bone CT images. A total of 654 images from 165 temporal bone CTs were divided into the training set (n = 534) and the testing set (n = 120). A target region that includes the area of the cochlear was extracted to create a diagnostic model. 4 models were used: ResNet10, ResNet50, SE-ResNet50, and DenseNet121. The testing data set was subsequently analyzed using these models and by 4 doctors. The areas under the curve was 0.91, 0.94, 0.93, and 0.73 in ResNet10, ResNet50, SE-ResNet50, and DenseNet121. The accuracy of ResNet10, ResNet50, and SE-ResNet50 is better than chief physician. Deep learning technique implied a promising prospect for clinical application of artificial intelligence in the diagnosis of cochlear malformation based on CT images.

Incomplete Partition Type II Cochlear Malformations: Delineating the Three-Dimensional Structure from Digitized Human Histopathological Specimens.

There are clinically relevant differences in scalae anatomy and spiral ganglion neuron (SGN) quantity between incomplete partition type II (IP-II) and normal cochleae. IP-II is a commonly implanted cochlear malformation. Detailed knowledge of intracochlear three-dimensional (3D) morphology may assist with cochlear implant (CI) electrode selection/design and enable optimization of audiologic programming based on SGN maps. IP-II (n = 11) human temporal bone histological specimens were identified from the National Institute on Deafness and Other Communication Disorders National Temporal Bone Registry and digitized. The cochlear duct, scalae, and surgically relevant anatomy were reconstructed in 3D. A machine learning algorithm was applied to map the location and number of SGNs. 3D scalae morphology of the basal turn was normal. Scala tympani (ST) remained isolated for 540 degrees before fusing with scala vestibuli. Mean ST volume reduced below 1 mm 2 after the first 340 degrees. Scala media was a distinct endolymphatic compartment throughout; mean ± standard deviation cochlear duct length was 28 ± 3 mm. SGNs were reduced compared with age-matched norms (mean, 48%; range, 5-90%). In some cases, SGNs failed to ascend Rosenthal's canal, remaining in an abnormal basalward modiolar location. Two forms of IP-II were seen: type A and type B. A majority (98-100%) of SGNs were located in the basal modiolus in type B IP-II, compared with 76 to 85% in type A. Hallmark features of IP-II cochleae include the following: 1) fusion of the ST and scala vestibuli at a mean of 540 degrees, 2) highly variable and overall reduced SGN quantity compared with normative controls, and 3) abnormal SGN distribution with cell bodies failing to ascend Rosenthal's canal.

Evaluation of the Performance of OTOPLAN-Based Cochlear Implant Electrode Array Selection: A Retrospective Study.

Otoplan is a surgical planning software designed to assist with cochlear implant surgery. One of its outputs is a recommendation of electrode array type based on imaging parameters. In this retrospective study, we evaluated the differences in auditory outcomes between patients who were implanted with arrays corresponding to those recommended by the Otoplan software versus those in which the array selection differed from the Otoplan recommendation. Pre-operative CT images from 114 patients were imported into the software, and array recommendations were generated. These were compared to the arrays which had actually been implanted during surgery, both in terms of array type and length. As recommended, 47% of patients received the same array, 34% received a shorter array, and 18% received a longer array. For reasons relating to structure and hearing preservation, 83% received the more flexible arrays. Those who received stiffer arrays had cochlear malformations or ossification. A negative, although non-statistically significant correlation was observed between the CNC scores at 12 months and the absolute value of the difference between recommended array and implanted array. In conclusion, clinicians may be slightly biased toward shorter electrode arrays due to their perceived greater ability to achieve full insertion. Using 3D imaging during the pre-operative planning may improve clinicians' confidence to implant longer electrode arrays, where appropriate, to achieve optimum hearing outcomes.

Three-dimensionally visualized ossification and mineralization process of the otic capsule in a postnatal developmental mouse.

We aimed to elucidate the ossification process of the otic capsule in postnatal C57BL/6 mice and depict the three-dimensional (3D) process of otoconial mineralization in vivo. The otic capsules of C57BL/6 mice were stained with alizarin red and imaged/compared using micro-computed tomography on postnatal day (P) between P0 and P8, P10, P15, and P30 and 3-4 months old (P3-4Mo). We reconstructed 3D images of the otic capsule and otoconia and measured the bone mineral density using x-ray absorptiometry on each age. The 3D reconstructed otic capsule images revealed two ossification centers of the otic capsule at P0. One was observed around the ampulla of the superior semicircular canal and utricle, and the other was observed around the ampulla of the posterior semicircular canal. The cross-sectional views demonstrated that modiolar ossification developed from the base to the apex from P4 to P8. The inter-scalar septum ossified bidirectionally from the modiolus and bony otic capsule from P8 to P15. The mineralized otoconia were first detected in the utricle at P3 and saccular otoconia at P6. The density of the utricle and saccular otoconia showed different growth trends. To the best of our knowledge, this is the first study to demonstrate the 3D appearance of the otic capsule and otoconia in different developmental stages of mice. We also revealed that modiolar and inter-scalar septal calcification is the final event in the cochlea and that it can be susceptible to pathological conditions (cochlear congenital malformations and hereditary vestibular diseases). The unique features of the ossification process and duration may explain these pathological conditions observed in humans. 3.

Our Experience in 576 Cases of Cochlear Implant Surgery by Veria Technique.

To study and analyse the result obtained in cochlear implantation by Veria technique and evaluate the incidence of surgical complications and their management. Between Jan 1, 2014 to Jan 1, 2019, 602 cochlear implantations by Veria technique were done out of which 576 patients were analysed retrospectively for the study. The age range was between 18 months and 60 years. All 576 patients were operated by Veria technique. Out of 576 patients, 57 (9.9%) had abnormal cochlear malformation. Cytomegalovirus (CMV) being the most common non genetic cause of congenital hearing loss accounting to 60%. The overall complication rate of 5.5% was observed in 576 implanted patients. The analysis of the results shows that this method has certain advantages, which are: it is simple and therefore the learning curve is fast; it is safe for the facial nerve, as the drilling is precisely controlled by the special perforator; it produces minimal bone trauma and due fast healing, it permits early fitting a few days after operation; it can be used for very small children where the mastoid may have not been yet sufficiently developed.

Cochlear Implant in cochlear Hypoplasia type 4 with Chiari Malformation- Case Report.

Cochlear hypoplasia type IV is a rare cochlear malformation with hypoplastic middle and apical turns while basal turn develops normally, it often coexist with other genetic mutations. We present a case of 4 year old with chiari malformation type 1 along with bilateral Cochlear hypoplasia type IV who underwent cochlear implantation.

A New Treatment Option in Incomplete Partition Type III: The Varese Bone-Air Stimulation (B.A.S.).

The incomplete partition type III is a severe cochlear malformation present in X-linked deafness. It is a rare, non-syndromic cause of severe to profound mixed hearing loss, often progressive. The complete absence of bony modiolus and the wide communication between the cochlea and the internal auditory canal make cochlear implantation challenging, with still no consensus on the management of these patients. To the best of our knowledge, no results have ever been published in the literature on the treatment of these patients with hybrid stimulation (bone and air). We present three cases in which this hybrid stimulation gave better audiological results then air stimulation alone. A literature review on audiological results of the current treatment options in children affected by IPIII malformation was conducted independently by two researchers. Ethical considerations on the treatment of these patients were conducted by the Bioethics department of the University of Insubria. In two of the patients, the bone-air stimulation, associated with prosthetic-cognitive rehabilitation, meant that surgery was avoided, obtaining similar communication performances of those present in the literature. We believe that, when the bone threshold appears partially preserved, a stimulation through the bone or hybrid modality, such as the Varese B.A.S. stimulation, should be attempted.

Vestibular Loss in Children Affected by LVAS and IP2 Malformation and Operated with Cochlear Implant.

This is a single center cohort study regarding the prevalence of vestibular loss in hearing impaired children affected by large vestibular aqueduct syndrome (LVAS) with incomplete cochlear partition malformation type II (IP2), fitted with cochlear implant (CI). Twenty-seven children received CI operations at 0.4-13 years on one or both ears and tested for vestibular loss with head impulse test, video head impulse test, mini ice-water test and cervical VEMP. Vestibular loss was found in 19% of operated ears and in 13.9% of non-operated ears. The difference was not statistically significant and was not significantly modified by age at implantation, age at testing, sex, presence of SLC26A4 gene mutation or bilaterality. However, the presence of anatomic anomalies at the level of the vestibulum or semicircular canals was significantly associated with a higher incidence of vestibular loss in CI operated children but not in those non-operated. No other factors, such as the surgical access, the electrode type, the presence of Gusher perioperatively, or post-operative vertigo modified significantly the prevalence of vestibular loss. In conclusion, LVAS/IP2 appears to be the major determinant of vestibular loss in these children, with a less obvious impact of CI, excluding the cases with vestibulum/canal anomalies: this group might have a higher risk for vestibular loss after CI surgery.

The Genetic Background of Hearing Loss in Patients with EVA and Cochlear Malformation.

The most frequently observed congenital inner ear malformation is enlarged vestibular aqueduct (EVA). It is often accompanied with incomplete partition type 2 (IP2) of the cochlea and a dilated vestibule, which together constitute Mondini malformation. Pathogenic SLC26A4 variants are considered the major cause of inner ear malformation but the genetics still needs clarification. The aim of this study was to identify the cause of EVA in patients with hearing loss (HL). Genomic DNA was isolated from HL patients with radiologically confirmed bilateral EVA (n = 23) and analyzed by next generation sequencing using a custom HL gene panel encompassing 237 HL-related genes or a clinical exome. The presence and segregation of selected variants and the CEVA haplotype (in the 5' region of SLC26A4) was verified by Sanger sequencing. Minigene assay was used to evaluate the impact of novel synonymous variant on splicing. Genetic testing identified the cause of EVA in 17/23 individuals (74%). Two pathogenic variants in the SLC26A4 gene were identified as the cause of EVA in 8 of them (35%), and a CEVA haplotype was regarded as the cause of EVA in 6 of 7 patients (86%) who carried only one SLC26A4 genetic variant. In two individuals with a phenotype matching branchio-oto-renal (BOR) spectrum disorder, cochlear hypoplasia resulted from EYA1 pathogenic variants. In one patient, a novel variant in CHD7 was detected. Our study shows that SLC26A4, together with the CEVA haplotype, accounts for more than half of EVA cases. Syndromic forms of HL should also be considered in patients with EVA. We conclude that to better understand inner ear development and the pathogenesis of its malformations, there is a need to look for pathogenic variants in noncoding regions of known HL genes or to link them with novel candidate HL genes.

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.