Cochlear Malformation Research Articles

SLC26A4 mutation testing for hearing loss associated with enlargement of the vestibular aqueduct.

Pendred syndrome (PS) is characterized by autosomal recessive inheritance of goiter associated with a defect of iodide organification, hearing loss, enlargement of the vestibular aqueduct (EVA), and mutations of the SLC26A4 gene. However, not all EVA patients have PS or SLC26A4 mutations. Two mutant alleles of SLC26A4 are detected in ¼ of North American or European EVA populations, one mutant allele is detected in another ¼ of patient populations, and no mutations are detected in the other ½. The presence of two mutant alleles of SLC26A4 is associated with abnormal iodide organification, increased thyroid gland volume, increased severity of hearing loss, and bilateral EVA. The presence of a single mutant allele of SLC26A4 is associated with normal iodide organification, normal thyroid gland volume, less severe hearing loss and either bilateral or unilateral EVA. When other underlying correlations are accounted for, the presence of a cochlear malformation or the size of EVA does not have an effect on hearing thresholds. This is consistent with observations of an Slc26a4 mutant mouse model of EVA in which hearing loss is independent of endolymphatic hydrops or inner ear malformations. Segregation analyses of EVA in families suggest that the patients carrying one mutant allele of SLC26A4 have a second, undetected mutant allele of SLC26A4, and the probability of a sibling having EVA is consistent with its segregation as an autosomal recessive trait. Patients without any mutations are an etiologically heterogeneous group in which siblings have a lower probability of having EVA. SLC26A4 mutation testing can provide prognostic information to guide clinical surveillance and management, as well as the probability of EVA affecting a sibling.

High prevalence of inner-ear and/or internal auditory canal malformations in children with unilateral sensorineural hearing loss

ObjectiveRadiological and genetic examination has recently advanced for diagnosis of congenital hearing loss. The aim of this study was to elucidate the prevalence of inner-ear and/or internal auditory canal malformations in children with unilateral sensorineural hearing loss (USNHL) for better management of hearing loss and genetic and lifestyle counseling. MethodsWe conducted a retrospective study of charts and temporal bone computed tomography (CT) findings of 69 consecutive patients 0–15 years old with USNHL. In two cases, genetic examination was conducted. ResultsOf these patients, 66.7% had inner-ear and/or internal auditory canal malformations. The prevalence of malformations in infants (age <1 year) was 84.6%, which was significantly higher than that in children 1–15 years old (55.8%; p<0.01). Almost half of the patients (32; 46.4%) had cochlear nerve canal stenosis; 13 of them had cochlear nerve canal stenosis alone, and in 19 it accompanied other malformations. Internal auditory canal malformations were observed in 22 subjects (31.8%), 14 (20.3%) had cochlear malformations, and 5 (7.2%) had vestibular/semicircular canal malformations. These anomalies were seen only in the affected ear, except in two of five patients with vestibular and/or semicircular canal malformations. Two patients (2.9%) had bilateral enlarged vestibular aqueducts. Mutations were found in SLC26A4 in one of the two patients with bilateral large vestibular aqueducts. The prevalence of a narrow internal auditory canal was significantly higher in subjects with cochlear nerve canal stenosis (50.0%) than in subjects with normal cochlear nerve canals (11.1%; p<0.01). There were no correlations between the type and number of malformations and hearing level. ConclusionsThe prevalence of inner-ear and/or internal auditory canal malformations detected by high-resolution temporal bone CT in children with USNHL was very high. Radiological and genetic examination provided important information to consider the pathogenesis and management of hearing loss. Temporal bone CT should be recommended to children with USNHL early in life. SLC26A4 mutation also should be examined in cases with bilateral enlarged vestibular aqueduct.

Audiological and radiological characteristics of a family with T961G mitochondrial mutation

Objective: The aim of this study was to describe audiological and radiological characteristics, and other secondary aspects, in a family carrying a T961G mutation in the 12S rRNA mitochondrial gene. Design: Case report. Study sample: Six members of a family participated in an audiological evaluation that included pure-tone audiometry, immittance tests, auditory brainstem responses (ABR), and otoacoustic emissions (OAE). The radiological evaluation was conducted through temporal bone CT scans using a Toshiba 16 channels Aquilon Spirale. Neuropsychiatric evaluation was also administered. Results: Three participants were diagnosed with severe sensorineural hearing loss of cochlear origin and cochlear malformations visible in CT scans. One participant had a mild mixed-hearing loss and no cochlear malformations. Two participants had normal audiological and radiological findings. Conclusions: We believe our study can provide helpful insight on the clinical findings of a rare mutation, of which few data have been presented in literature.

Mondini Deformity in a Case of Turner Syndrome. A Radiological Finding

Turner syndrome (TS) is the human being's most frequent sex chromosome abnormality. Progressive sensorineural hearing loss is documented in more than 50% of the women affected by this syndrome. Although Mondini defect is the cochlear congenital malformation most frequently identified in other polymalformative syndromes, it has rarely been reported in TS. We describe the case of a 32-year-old woman with TS who presented progressive sensorineural hearing loss. The computed tomography of the ears showed bilateral Mondini deformity.

Characteristics and application of inner ear CT in 20 cases of sensorineural hearing loss in children

Conclusion: This study shows that a number of children with sensorineural hearing loss (SNHL) have inner ear malformations demonstrated by multi-slice spiral computed tomography (MSCT). MSCT allows a comprehensive assessment of various congenital inner ear malformations through high quality multiplanar reformation (MPR) and can display the site and degree of the malformation three-dimensionally and intuitively. This is very useful for cochlear implantation. Objective: To evaluate the feasibility and usability of MSCT in pediatric SNHL with inner ear malformations. Methods: Sixty-five patients were diagnosed with SNHL by brainstem auditory evoked response (BAER). Inner ear MSCT scan and coronal MPR reconstruction were performed in all cases. Results: This study demonstrated 20 cases (33 ears) with inner ear malformations, which included 10 ears with cochlear malformations, 7 with vestibular malformations, 5 with semicircular canal malformations, 8 with internal auditory canal (IAC) malformations, and 15 with vestibular malformations. Cochlear malformations included one ear with Michel deformity, two ears with common cavity deformity, one with cochlear aplasia, one with hypoplastic cochlea, two with incomplete partition type I, and three with incomplete partition type II (Mondini deformity).

Air-Bone Gap Component of Inner-Ear Origin in Audiograms of Cochlear Implant Candidates

Experimental studies have shown that creating a window in the bony cover of the cochlea and vestibular parts of the inner ear, with preservation of membranous and middle-ear functions, induces an air-bone gap (ABG). This study sought to determine if a similar mechanism explains the ABG frequently observed in audiograms of cochlear implant candidates. The study group included 47 candidates for a cochlear implant (94 ears) attending a university-affiliated tertiary medical center who had an ABG component in the audiogram in the absence of external or middle-ear abnormalities. Air- and bone-conduction thresholds on pure-tone audiometry were analyzed for 250 to 8,000 Hz and 250 to 4,000 Hz, respectively. In the 25 patients operated on during the study period, differences in the ABG and in cerebrospinal fluid (CSF) leak were compared between those with and without anomalies on computed tomography. Imaging revealed an abnormal inner-ear structure in 46% of cases, mostly a large vestibular aqueduct, alone or combined with other cochlear or vestibular malformations. ABG was evident over high and low frequencies and was significantly larger at low frequencies and in ears with structural anomalies. A high rate of CSF leak was observed in patients with an ABG and structural anomalies imaging as well as in those with an ABG and normal imaging findings. In cochlear implant candidates, the presence of a third window could cause an ABG because of stapes motion-induced shunting of acoustic energy outside the cochlear duct in response to air-conducted stimuli while bone conduction is preserved.

Auditory brainstem implant outcomes and MAP parameters: Report of experiences in adults and children

The auditory brainstem implant (ABI) was first developed to help neurofibromatosis type 2 patients. Recently, its use has been recently extended to adults with non-tumor etiologies and children with profound hearing loss who were not candidates for a cochlear implant (CI). Although the results has been extensively reported, the stimulation parameters involved behind the outcomes have received less attention. Objective The aim of this study is to describe the audiologic outcomes and the MAP parameters in ABI adults and children at our center. Methods Retrospective chart review. Five adults and four children were implanted with the ABI24M from September 2005 to June 2009. In the adult patients, four had Neurofibromatosis type 2, and one had postmeningitic deafness with complete ossification of both cochleae. Three of the children had cochlear malformation or dysplasia, and one had complete ossified cochlea due to meningitis. Map parameters as well as the intraoperative electrical auditory brainstem responses were collected. Evaluation was performed with at least six months of device use and included free-field hearing thresholds, speech perception tests in the adult patients and for the children, the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) and (ESP) were used to evaluate the development of auditory skills, besides the MUSS to evaluate. Results The number of active electrodes that did not cause any non-auditory sensation varied from three to nineteen. All of them were programmed with SPEAK strategy, and the pulse widths varied from 100 to 300 μs. Free-field thresholds with warble tones varied from very soft auditory sensation of 70 dBHL at 250 Hz to a pure tone average of 45 dBHL. Speech perception varied from none to 60% open-set recognition of sentences in silence in the adult population and from no auditory sensation at all to a slight improvement in the IT-MAIS/MAIS scores. Conclusion We observed that ABI may be a good option for offering some hearing attention to both adults and children. In children, the results might not be enough to ensure oral language development. Programming the speech processor in children demands higher care to the audiologist.

CT Scan Value Of Temporal Bone In Assessment Of Congenital Deafness

Background:. Computed tomography (CT) of the temporal bone is the first-line recommended imaging modality for SNHL. Because it can identify inner ear malformations that may be responsible for hearing impairment.Objectives: To demonstrate CT abnormalities encountered in children with congenital deafness and to assess the value of CT in the prediction for cochlear implantation. Also to evaluate the incidence and types of inner ear abnormalities in children with congenital deafness identified with CT scan for implantation difficulties.Patients &amp; Methods: This is a cross sectional study carried out during the period from October 2009 to October 2010 at Baghdad medical city complex on children patients who are suffering from congenital deafness. The study included 60 patients (120 ears), 27 males and 33 females, were evaluated by CT scan of temporal bone before cochlear implants.Results: Most of the cases undergo CT scan examination were normal (80%). Enlargement of the vestibular aqueduct is most common (10% ) causes of congenital inner ear malformations, followed by cochlear malformation (8.3%) while dysplasia of lateral semicircular canal found in (3.3%) of cases.Conclusion: High resolution CT scan is recommended in all patient for pre implant analysis of temporal bone morphology due to its reliability and easy availability. CT scan is the modality provided critical information on abnormalities of the otic capsule, pneumatisation of the mastoid, middle ear abnormalities, cochlear ducts patency and vascular abnormalities- thus helping to assess the suitability of the ear for implantation, determine the side to be implanted and to find any associated abnormality which could adversely influence the surgery or post operative period.

Implants cochléaires chez l’adulte

Cochlear implant in adults is a procedure, dedicated to rehabilitate severe to profound hearing loss. Because of technological progresses and their applications for signal strategies, new devices can improve hearing, even in noise conditions. Binaural stimulation, cochlear implant and hearing aid or bilateral cochlear implants are the best opportunities to access to better level of comprehension in all conditions and space localisation. By now minimally invasive surgery is possible to preserve residual hearing and use a double stimulation modality for the same ear: electrical for high frequencies and acoustic for low frequencies. In several conditions, cochlear implant is not possible due to cochlear nerve tumour or major malformations of the inner ear. In these cases, a brainstem implantation can be considered. Clinical data demonstrate that improvement in daily communication, for both cochlear and brainstem implants, is correlated with cerebral activation of auditory cortex.

Comparisons of Auditory Performance and Speech Intelligibility in Children With Cochlear Implants Placed Using Different Approaches

To demonstrate whether there are differences in the outcomes of children with cochlear implants using the techniques between mastoidectomy with posterior tympanotomy (MPTA) and suprameatal approach (SMA). A total of 44 congenitally deaf children who underwent cochlear implantation before the age of 5 years at the Sixth Hospital Affiliated to Shanghai Jiao tong University from January 2005 to March 2008 were included in this study. Children with severe mental retardation or with cochlear malformations were excluded. Each group had 22 patients; however, 4 patients in the SMA group and 5 in the MPTA group were not included in this study because the assessments for these patients were not available. All children were assessed before surgery and 6, 12, and 24 months after surgery with Categories of Auditory Performance (CAP) and Speech Intelligibility Rating (SIR). Each assessment was given by the child's speech therapist in the familiar environment of the child's home or school. At each interval, the CAP and SIR scores of each group were compared. For the both groups, CAP and SIR scores increased with the time of implant usage during the follow-up period after implantation. However, there were no significant differences in scores of CAP and SIR at the 4 time points between the SMA group and the MPTA group. Intelligible speech and auditory performance of children with cochlear implantation using the SMA were good. There were no differences between children implanted with the SMA technique versus the MPTA technique.

Redundant functions of Rac GTPases in inner ear morphogenesis

Development of the mammalian inner ear requires coordination of cell proliferation, cell fate determination and morphogenetic movements. While significant progress has been made in identifying developmental signals required for inner ear formation, less is known about how distinct signals are coordinated by their downstream mediators. Members of the Rac family of small GTPases are known regulators of cytoskeletal remodeling and numerous other cellular processes. However, the function of Rac GTPases in otic development is largely unexplored. Here, we show that Rac1 and Rac3 redundantly regulate many aspects of inner ear morphogenesis. While no morphological defects were observed in Rac3 −/− mice, Rac1 CKO ; Rac3 −/− double mutants displayed enhanced vestibular and cochlear malformations compared to Rac1 CKO single mutants. Moreover, in Rac1 CKO ; Rac3 −/− mutants, we observed compromised E-cadherin-mediated cell adhesion, reduced cell proliferation and increased cell death in the early developing otocyst, leading to a decreased size and malformation of the membranous labyrinth. Finally, cochlear extension was severely disrupted in Rac1 CKO ; Rac3 −/− mutants, accompanied by a loss of epithelial cohesion and formation of ectopic sensory patches underneath the cochlear duct. The compartmentalized expression of otic patterning genes within the Rac1 CKO ; Rac3 −/− mutant otocyst was largely normal, however, indicating that Rac proteins regulate inner ear morphogenesis without affecting cell fate specification. Taken together, our results reveal an essential role for Rac GTPases in coordinating cell adhesion, cell proliferation, cell death and cell movements during otic development.

Auditory maturity and hearing performance in inner ear malformations: a histological and electrical stimulation approach

The objective of this study was to assess the auditory performance of the neural structures in response to controlled electrical stimulation period. A prospective cohort study focused on the intracochlear electrical stimulation parameters and hearing performance of patients suffering different cochlear malformations who were treated by cochlear implants constituted the study design. The study sample constituted 16 patients, suffering profound prelingual hearing impairment, diagnosed on the basis of radiological criteria as having an inner ear malformation, and who underwent cochlear implantation and were followed for 24 months. Patients with common cavities, characterized by fewer nerve structures involved, less epithelial penetration, and deficient cochlear tonotopy distribution showed have higher thresholds and electrical charges than patients with cochlear hypoplasia, who in turn have higher thresholds than patients with minor malformations (p < 0.05). Furthermore, word perception was severely compromised in patients with a common cavity malformation and was also poor in patients with cochlear hypoplasia, who were unable to discriminate more than 50% of the words and relied on visual cues as a necessary aid to communication. Better results were reached by minor malformed inner ears. To conclude, the number of nerve structures involved, epithelial penetration and deficient cochlear tonotopy are responsible of inner ear functionality.

Evaluation of Objective Test Techniques in Cochlear Implant Users With Inner Ear Malformations

The aim of the study was to compare results of objective test techniques in cochlear implant users with inner ear malformations and incomplete partition anomalies with types I and II and to show which techniques should be used in the evaluation and fitting of cochlear implant users with inner ear malformations. Retrospective clinical study. The subjects in the control group were selected randomly from cochlear implant users with normal cochlea. Inclusion criteria for patients group were having inner ear malformation for the study group and at least 1 year cochlear implants use for both groups. For each individual subject, electrically evoked compound action potentials (ECAPs), electrically evoked stapedius reflex threshold (ESRT), and electrically evoked auditory brainstem response (EABR) thresholds were determined. These tests were applied after a normal cochlear implant fitting session. There were 20 subjects in inner ear malformation group and 15 subjects in the control group. For each subject, 6 intracochlear electrodes, representing apical, middle, and basal array of intracochlear electrode, were used. In the cochlear malformation group, percentage of acquired ECAP thresholds was 25%. However, in the control group, percentage of ECAP was 74%. Similarly with ECAP, percentage of ESRT in the cochlear malformation group was 17.5%, and that in the control group was 90%. The difference between these percentages was statistically significant. Both current levels and latencies of EABR wave V were significantly different from each other for the inner ear malformation group and the control group. For statistical analysis, Mann-Whitney U test for 2 independent samples, Kruskal-Wallis analysis and Dunn's Z test were used. For the inner ear malformation group, EABR is a more applicable objective test technique when compared with ECAP and ESRT.

An Anatomical Study of the Cochlea among Filipinos using High-Resolution Computed Tomography Scans

Objective: To describe the cochlear anatomy among Filipinos through high resolution computed&#x0D; tomography (HRCT) imaging.&#x0D; &#x0D; Methods:&#x0D; Design: Retrospective Study&#x0D; Setting: Tertiary Private University Hospital&#x0D; Patients: Cochlear images retrospectively obtained from computed tomography (CT) scans of subjects who underwent cranial, facial, paranasal sinus and temporal bone computed tomography from October 2009 to July 2010 were reconstructed and analyzed.&#x0D; &#x0D; Results: 388 cochlear images were obtained from the scans of 194 subjects (101 males and 93 females, aged 1 to 90 years old, mean = 52 years) and reconstructed for analysis. The mean coiled cochlear height measured 4.36 mm on the right (A.D.) and 4.34 mm on the left (A.S.). Measurement from the oval window to the distal end of the basal turn (equivalent to the horizontal dimension of the cochlea or the mean length of the basal turn) was 7.55 mm A.D. and 7.60 mm A.S. The vertical and horizontal dimensions of right and left cochleas were identical in all subjects (S.D. = 0.35). The right and left cochlear turns were identical in each subject, exhibiting 2 ½ turns in 92.3% of subjects and 2 ¾ turns in 7.7% of subjects.The cochlear dimensions were similar in all subjects, regardless of age. No cochlear ossification or malformation was noted on any CT image.&#x0D; &#x0D; Conclusion: The 7.55 mm mean length of the cochlear basal turn among Filipinos in this study was 1.24 mm shorter than the average length of the basal turn of 8.81 mm reported elsewhere. Further studies of the cochlear dimensions in specific age groups and its correlation to audiometric status are recommended to determine other significant physiologic correlations.&#x0D; &#x0D; Keywords: cochlea, cochlear turn, high-resolution computed tomography (HRCT), magnetic resonance imaging (MRI)

Deformidad de Mondini en un caso de síndrome de Turner. Un hallazgo radiológico

Turner syndrome (TS) is the human being's most frequent sex chromosome abnormality. Progressive sensorineural hearing loss is documented in more than 50% of the women affected by this syndrome. Although Mondini defect is the cochlear congenital malformation most frequently identified in other polymalformative syndromes, it has rarely been reported in TS. We describe the case of a 32-year-old woman with TS who presented progressive sensorineural hearing loss. The computed tomography of the ears showed bilateral Mondini deformity.

C037 Outcome of cochlear implantation in children with cochlear malformations

C037 Outcome of cochlear implantation in children with cochlear malformations

C010 Construction of a global performance indicator derived from a statistical analysis of outcomes for cochlear implants

The auditory brainstem implant (ABI) was first developed to help neurofibromatosis type 2 patients. Recently, its use has been recently extended to adults with non-tumor etiologies and children with profound hearing loss who were not candidates for a cochlear implant (CI). Although the results has been extensively reported, the stimulation parameters involved behind the outcomes have received less attention.The aim of this study is to describe the audiologic outcomes and the MAP parameters in ABI adults and children at our center.Retrospective chart review. Five adults and four children were implanted with the ABI24M from September 2005 to June 2009. In the adult patients, four had Neurofibromatosis type 2, and one had postmeningitic deafness with complete ossification of both cochleae. Three of the children had cochlear malformation or dysplasia, and one had complete ossified cochlea due to meningitis. Map parameters as well as the intraoperative electrical auditory brainstem responses were collected. Evaluation was performed with at least six months of device use and included free-field hearing thresholds, speech perception tests in the adult patients and for the children, the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) and (ESP) were used to evaluate the development of auditory skills, besides the MUSS to evaluate.The number of active electrodes that did not cause any non-auditory sensation varied from three to nineteen. All of them were programmed with SPEAK strategy, and the pulse widths varied from 100 to 300 μs. Free-field thresholds with warble tones varied from very soft auditory sensation of 70 dBHL at 250 Hz to a pure tone average of 45 dBHL. Speech perception varied from none to 60% open-set recognition of sentences in silence in the adult population and from no auditory sensation at all to a slight improvement in the IT-MAIS/MAIS scores.We observed that ABI may be a good option for offering some hearing attention to both adults and children. In children, the results might not be enough to ensure oral language development. Programming the speech processor in children demands higher care to the audiologist.

C007 Binaural results in children with bilateral implantation

The auditory brainstem implant (ABI) was first developed to help neurofibromatosis type 2 patients. Recently, its use has been recently extended to adults with non-tumor etiologies and children with profound hearing loss who were not candidates for a cochlear implant (CI). Although the results has been extensively reported, the stimulation parameters involved behind the outcomes have received less attention.The aim of this study is to describe the audiologic outcomes and the MAP parameters in ABI adults and children at our center.Retrospective chart review. Five adults and four children were implanted with the ABI24M from September 2005 to June 2009. In the adult patients, four had Neurofibromatosis type 2, and one had postmeningitic deafness with complete ossification of both cochleae. Three of the children had cochlear malformation or dysplasia, and one had complete ossified cochlea due to meningitis. Map parameters as well as the intraoperative electrical auditory brainstem responses were collected. Evaluation was performed with at least six months of device use and included free-field hearing thresholds, speech perception tests in the adult patients and for the children, the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) and (ESP) were used to evaluate the development of auditory skills, besides the MUSS to evaluate.The number of active electrodes that did not cause any non-auditory sensation varied from three to nineteen. All of them were programmed with SPEAK strategy, and the pulse widths varied from 100 to 300 μs. Free-field thresholds with warble tones varied from very soft auditory sensation of 70 dBHL at 250 Hz to a pure tone average of 45 dBHL. Speech perception varied from none to 60% open-set recognition of sentences in silence in the adult population and from no auditory sensation at all to a slight improvement in the IT-MAIS/MAIS scores.We observed that ABI may be a good option for offering some hearing attention to both adults and children. In children, the results might not be enough to ensure oral language development. Programming the speech processor in children demands higher care to the audiologist.

E105 Response to sound perception of cochlear implant in cochlear malformation and its surgical complications

Events happen within the organizational world not by chance but for reasons. It is surely the task of management research to try to explain why these events occur. This requires us to understand the nature of causality but, in general, this is seldom discussed in the management or IS literature. The standard, positivist view underlying statistical analysis is the Humean one of constant conjunctions of events leading to universal laws. Against this, many constructivists find the whole idea of external causality implausible. In this paper we explore a third alternative that is developing strongly within the philosophy of science, social theory and critical realism – the mechanisms view. This proposes that events are generated through the interaction of specific mechanisms endowed with causal powers that may or may not be triggered, and may or may not be countervailed. In particular, the paper develops some of the fundamental concepts such as the nature of events, emergent properties, the difference between properties and powers, casual interactions between levels, absences as causes, event causality and generative causality, and abstracting causal regularities. The paper concludes by illustrating these ideas with a series of empirical case studies.

Temporal bone abnormalities in children with GJB2 mutations

To determine the incidence of temporal bone abnormalities in children with sensorineural hearing loss (SNHL) and pathogenic biallelic GJB2 mutations. Retrospective analysis of a large cohort of pediatric patients with biallelic GJB2 mutations and SNHL (observational case series). Blinded review of all available temporal bone computed tomographic (CT) and magnetic resonance imaging (MRI) studies in this cohort. Out of 158 patients with biallelic GJB2 mutations, 113 had CT and/or MRI studies available for review. Definite, although generally subtle, inner ear abnormalities were present in 12/113. There were malformations of the semicircular canals (SCC) in 4/12, of the internal auditory canal in 2/12, of the cochlear nerve canal (CNC) in 6, and unilateral cochlear malformation in 1/12. MRI in 1/5 showed mildly hypoplastic cochlear nerve. There was no correlation between SNHL severity and presence/absence/type of malformations or genotype. Our study of 113 biallelic GJB2 patients with SNHL and temporal bone imaging is the largest study to date. We found only 10% had any abnormalities, most subtle, and none had EVA. Additionally, there was no correlation between SNHL severity and presence/absence/type of malformations or genotype. Disparities between our group and previous reports may be due to differences in degree of hearing loss, types of mutations, populations studied, and radiologic factors for both image acquisition and interpretation.