Internal Auditory Canal Diverticula in Children: A Congenital Variant.

OBJECTIVES/HYPOTHESIS: Internal auditory diverticula in adults have been found to exist independent of otosclerosis, and in the presence of otosclerosis. We sought to determine the prevalence of internal auditory canal (IAC) diverticula in a pediatric cohort, to assess whether IAC diverticula are a risk factor for hearing loss, and the co-occurrence of otic capsule hypoattenuation. STUDY DESIGN: Retrospective review. METHODS: A single-site retrospective review of high-resolution temporal bones computed tomography (CT) scans including the presence and size of diverticula and hypoattenuation of the otic capsule. Demographic, imaging, and audiometric data were collected and descriptively analyzed. Bivariate analysis of collected variables was conducted. Comparisons between sides in unilateral cases were also performed. RESULTS: 16/600 (2.7%; 95% CI [2.0%, 3.4%]) were found to have IAC diverticula. Six were bilateral. Thirty-one patients (5.2%) were found to have hypoattenuation of the otic capsule. There were no coincident cases of IAC diverticulum and hypoattenuation of the otic capsule. There was no association between the presence of IAC diverticula and age (P = .13). In six patients with unilateral diverticula, pure tone average (P = .42), and word recognition (P = .27) scores were not significantly different when compared to the normal, contralateral side. CONCLUSIONS: The prevalence of IAC diverticula in children is lower than the prevalence in adults. IAC diverticula in children likely represent congenital variants of temporal bone anatomy. Similar to adult populations, there is evidence that IAC diverticula in children are likely not an independent risk factor for hearing loss. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1683-E1687, 2021.

Inner-ear malformations as a cause of single-sided deafness.

OBJECTIVE: To determine the prevalence and distribution of inner-ear malformations in congenital single-sided deafness cases, as details of malformation type are crucial for disease prognosis and management. METHODS: A retrospective study was conducted of 90 patients aged under 16 years with congenital single-sided deafness. Radiological findings were evaluated using computed tomography and magnetic resonance imaging. Inner-ear malformations were identified and cochlear nerve status was determined in affected ears. RESULTS: Out of 90 ears, 42 (46.7 per cent) were found to have inner-ear malformation. Isolated cochlear aperture stenosis was the most common anomaly (n = 18, 20 per cent), followed by isolated cochlear aperture atresia (n = 11, 12.2 per cent) and cochlear hypoplasia (n = 7, 7.8 per cent). Cochlear nerve deficiency was encountered in 41 ears (45.6 per cent). The internal auditory canal was also stenotic in 49 ears (54.4 per cent). CONCLUSION: Inner-ear malformations, especially cochlear aperture anomalies, are involved in the aetiology of single-sided deafness more than expected. The cause of single-sided deafness differs greatly between congenital and adult-onset cases. All children with single-sided deafness should undergo radiological evaluation, as the prognosis and management, as well as the aetiology, may be significantly influenced by inner-ear malformation type.

Clinical outcomes following cochlear implantation in children with inner ear anomalies.

OBJECTIVE: A significant proportion of children with congenital hearing loss who are candidates for cochlear implants (CIs) may have inner ear malformations (IEMs). Surgical and speech outcomes following CI in these children have not been widely reported. METHODS: The charts of children who were evaluated for a CI between 1/1/1986 and 12/31/2014 at a university-based tertiary level pediatric cochlear implant center were reviewed. Principal inclusion criteria included (i) age 1-18 years, (ii) history of bilateral severe to profound sensorineural hearing loss, and (iii) limited benefit from binaural amplification. Exclusion criteria included (i) underlying diagnosis of neurodevelopmental disorder and (ii) lack of follow up for speech assessment if a CI was performed. The following outcome measures were reviewed: (i) imaging findings with magnetic resonance imaging or high resolution computed tomography, (ii) intraoperative complications, and (iii) speech perception categorized as the ability to perceive closed set, open set, or none. RESULTS: The prevalence of IEMs was 27% (102 of 381), of which 79% were bilateral. Cochlear dysplasia accounted for 30% (40 of 136) of the anomalies. Seventy-eight of the 102 patients received a CI (78%). Surgery was noted to be challenging in 24% (19 of 78), with a perilymphatic gusher being the most common intraoperative finding. Cochlear dysplasia, vestibular dysplasia and cochlear nerve hypoplasia were associated with poor speech perception (open OR closed set speech recognition scores, 0-23%), although the outcomes in children with enlarged vestibular aqueduct were similar to those of children with normal inner ear anatomy (65%). CONCLUSIONS: Cochlear implantation is safe in children with IEMs. However, the speech perception outcomes are notably below those of patients with normal anatomy, with the exception of when an enlarged vestibular aqueduct is present.

Temporal High-Resolution Computed Tomography and Magnetic Resonance Imaging of Congenital Inner Ear Anomalies in Children.

Imaging plays an important role in determining indications of cochlear implantation and choosing candidates for the procedure in children. Temporal high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) can display precisely the complex anatomic structure of inner ear. Although HRCT permits detailed imaging of bony structures, MRI gives valuable information about membranous labyrinth, internal acoustic canal, and vestibulocochlear nerve. Magnetic resonance imaging examination of the brain should be performed at the same time to evaluate any coexistent brain parenchymal abnormality. These imaging modalities are complementary methods in evaluating congenital inner ear anomalies. The aim of this pictorial essay is to reviewing temporal HRCT and MRI findings of congenital inner ear anomalies.

[Optimization of the approach to the spiral (Rosenthal's) canal of the cochlea in the patients presenting with cochlear-vestibular abnormalities].

The objective of the present study was to improve the effectiveness of cochlear implantation (CI) in the patients presenting with cochlear-vestibular abnormalities based on the development and practical application of the algorithm for the insertion of an electrode arrayinto the spiral (Rosenthal's) canal of the cochlea taking into consideration the specific anatomical features of the middle and inner ears. The study included 25 patients with congenital malformations of the inner ear and bilateral grade IV sensorineural loss of hearing or deafness selected for CI. Indications for drilling a cochleostomy were the high localizationof the jugular bulb and the absence of its bone wall (5 patients, 20%). In the remaining cases, it proved possible to identify the round window and perform the transmembrane insertion of the active electrode. In 15 (69%) patients, the surgical intervention provoked intraoperative leakage of the cerebrospinal fluid that was successfully stopped by the careful tamponade of either the cochleostoma or the round window niche with the use of an automuscular flap. Taken together, good visualization of the round window and the transmembrane insertion of the active electrode into the spiral (Rosenthal's) canal of the cochlea in the patients presenting with cochlear-vestibular abnormalities made it possible to reduce to a minimum the injury to the spiral organ of the cochlea, control liquorrhea, and improve auditory performance in the postoperative period.

Congenital Malformations of the Inner Ear: Case Series and Review of the Literature.

Patients with craniofacial anomalies often present to doctors due to their noticeable disfigurement and are routinely assessed by otolaryngologists for hearing evaluation. However, small percentage of craniofacial anomaly patients may present with delayed speech though they may not have initial obvious external deformation. The objective of case series is to identify the congenital inner ear malformation. The series of clinical presentation, physical examination, investigations, treatments and follow-up results were demonstrated followed by the discussion.

Restudy of malformations of the internal auditory meatus, cochlear nerve canal and cochlear nerve.

The present study aims to restudy the correlation between the internal auditory meatus (IAM), the cochlear nerve canal (CNC), the cochlear nerve (CN) and inner ear malformations. In this retrospective study design, the abnormal diameter of the IAM, CNC and CN in patients with any kind of inner ear malformations was evaluated using multi-slice spiral computed tomography (MSCT) (37 patients) and magnetic resonance imaging (MRI) (18 patients). Of 37 MSCT-diagnosed patients, 2 had IAM atresia, 11 IAM stenosis, 22 enlarged IAM, and 2 normal IAM with an abnormal CN. MRI diagnoses of 18 patients revealed 8 cases of aplastic CN, 6 hypoplastic CN, and 4 normal CN. CNC stenosis was associated with CN hypoplasia (P < 0.001). Patients with absent or stenotic IAM had less CN development than those with normal or enlarged IAM (P = 0.001). We propose a modification of the existing classification systems with a view to distinguishing malformations of the IAM, CNC and CN.

Hearing and vertigo outcomes after congenital labyrinthine cholesteatoma resection.

Congenital labyrinthine cholesteatoma can cause varying degrees of hearing loss and vertigo. Hearing preservation is not always possible when treatment involves total labyrinthectomy. Since 1969, there have been several case reports and case series documenting hearing preservation following surgical treatment of congenital labyrinthine cholesteatoma. However, none of the case reports or case series documents the patients' vestibular complaints after surgery. Herein, we report a case series of four patients who were treated with the goal of hearing preservation and resolution of vertigo after partial or complete removal of the bony labyrinth for congenital inner ear cholesteatoma. We will also discuss possible explanations for the mechanisms of preservation of hearing and vestibular function with a review of the current literature.

Congenital dehiscence in the posterior semicircular canal.

HYPOTHESIS: Posterior semicircular canal dehiscence (PSCD) may be of congenital origin. BACKGROUND: PSCD is characterized by the lack of bone coverage, which results in its lumen being exposed to the meninges of the posterior cranial fossa or to the gulf of the jugular vein. It has an incidence of 0.2%. Its presence has been associated with several well-defined entities, although a congenital origin has not been proven. METHODS: We have analyzed, from a macroscopic, microscopic, and radiologic (computed tomography) viewpoint, the right temporal bone of a 32-week-old human fetus that presented a defect in the bone coverage located in the rear. RESULTS: The macroscopic study showed a solution of continuity in the posterior semicircular canal, with elliptic morphology and smooth edges. This defect was 3.4 mm long with a width that varied between 0.67 mm in its apical portion and 1.42 in the basal portion. The radiologic study (computed tomography) showed the absence of bone coverage of the posterior semicircular canal, which was open to the intracranial space in the posterior fossa. Its histologic study showed good bone coverage of this canal at the expense of compact bone tissue. However, at the medial end, there is a lack of bone coverage, resulting in the lumen of the canal being open to the intracranial space. The bone edges of the defect did not present any osteoclast activity. CONCLUSION: The lack of bone coverage (dehiscence) of the posterior semicircular canal in a 32-week-old fetus suggests a congenital component of bony dehiscences of this canal. Even so, this single finding does not conclusively prove the congenital component, and the dehiscence is a finding that can be part of and not by itself a syndrome.

Implantation of the common cavity malformation may prevent meningitis.

UNLABELLED: OBJECTIVES AND IMPORTANCE: Children with certain congenital malformations of the inner ear, including those with a common cavity defect, have a higher incidence of spontaneous cerebrospinal fluid (CSF) leak and resulting meningitis. However, they may also benefit from cochlear implantation. We suggest that surgical management may be possible that both prevents meningitis and provides hearing rehabilitation during the same procedure. CLINICAL PRESENTATION: A 2-year-old girl with bilateral common cavity defects who had previously undergone cochlear implantation developed contralateral CSF leak resulting in meningitis. INTERVENTION: After resolution of the infection, cochlear implantation was performed at the same time as definitive CSF leak repair. Simultaneous cochlear implantation and repair of the CSF leak successfully decreased the chance of recurrent meningitis in this case. She has been deriving hearing benefit from the bilateral implants. CONCLUSION: This case suggests a role for cochlear implantation to be combined with simultaneous CSF leak repair in children with a cochlear malformation. Furthermore, bilateral cochlear implantation at an early age may be warranted in these patients before CSF leaks and meningitis have occurred.

Recurrent bacterial meningitis in a child with hearing impairment, mondini dysplasia: a case report.

Recurrent bacterial meningitis is not a common disease and makes physicians seek underlying predisposing factors which can result from anatomic anomalies or immunodeficiency. In this paper we present a boy with recurrent bacterial meningitis with the history of trauma and sensorineural hearing loss. Mondini dysplasia was demonstrated with computed homographic scans (CT-Scan) of temporal bones.

Inner ear lesions in congenital cytomegalovirus infection of human fetuses.

Congenital cytomegalovirus (CMV) infection is the leading cause of non-hereditary congenital sensorineural hearing loss (SNHL). The natural course and the pathophysiology of inner ear lesions during human fetal CMV infection have not yet been reported. Inner ear lesions were investigated in six CMV-infected fetuses aged 19-35 postconceptional weeks and correlated with central nervous system (CNS) lesions. All the fetuses had high viral loads in the amniotic fluid and severe visceral and CNS lesions visible by ultrasound. Diffuse lesions consisting of both cytomegalic cells containing inclusion bodies and inflammation were found within all studied structures including the inner ear, brain, other organs, and placenta, suggesting hematogenous dissemination. Cochlear infection was consistently present and predominated in the stria vascularis (5/6), whereas the supporting cells in the organ of Corti were less often involved (2/6). Vestibular infection, found in 4/6 cases, was florid; the non-sensory epithelia, including the dark cells, were extensively infected. The endolymphatic sac was infected in 1 of 3 cases. The severity of inner ear infection was correlated with the CNS lesions, confirming the neurotropism of CMV. This study documenting infection of the structures involved in endolymph secretion and potassium homeostasis in fetuses with high amniotic fluid viral loads suggests that potassium dysregulation in the endolymphatic compartment of the inner ear may lead to secondary degeneration of the sensory structures. In addition, the occurrence of SNHL depends on the intensity and duration of the viral infection and inflammation.

Is superior canal dehiscence congenital or acquired? A case report and review of the literature.

This article presents a detailed case report of a patient who was diagnosed with superior canal dehiscence at 37 years of age, but who had a suspicious history for that syndrome from at least 10 years of age. The authors hypothesize several reasons for this late diagnosis, with the goal of helping pediatricians, otolaryngologists, and neurologists consider this syndrome in their differential diagnosis of children, adolescents, or adults experiencing dizziness.

Superior semicircular canal dehiscence: congenital or acquired condition?

BACKGROUND AND PURPOSE: It remains unclear whether SSCD syndrome, characterized by onset of vestibular symptoms in the setting of loud noises, is a congenital or acquired condition. The purpose of this investigation was to assess the prevalence of SSCD on imaging among multiple age groups to determine whether this condition is more likely to be congenital or acquired. MATERIALS AND METHODS: Following approval of the institutional review board, 306 consecutive temporal bone CT examinations performed between July 2005 and March 2007 were retrospectively reviewed. Of these, 2 patients were eliminated due to destructive processes in the inner ear. Patients ranged in age from 7 months to 89 years. Images were independently evaluated by 2 neuroradiologists, and the superior semicircular canal was characterized as normal, thin, or frankly dehiscent in each temporal bone. Any discrepancies were resolved by consensus. The patient list was then subcategorized into 5 age groups, and the prevalence of SSCD was calculated for each group. RESULTS: Twenty-four patients were identified with SSCD, of which 6 demonstrated dehiscence bilaterally. One hundred thirty-seven subjects were identified with thinning, of which 50 demonstrated thinning bilaterally. Each successively older age category experienced a 93% increase (95% CI, 30%-187%) in the prevalence of SSCD (P = .001) and a 9% increase (95% CI, -5%-25%) in the prevalence of thinning (P = .21). Neither crude nor age-adjusted models demonstrated a significant association between thinning and contralateral dehiscence or vice versa. CONCLUSIONS: The increased radiologic prevalence of SSCD among older age groups suggests that this is more commonly an acquired rather than congenital condition.

Delineating the hearing loss in children with enlarged vestibular aqueduct.

OBJECTIVE/HYPOTHESIS: To explore the clinical characteristics and audiologic outcomes in children with enlarged vestibular aqueduct (EVA). STUDY DESIGN: Retrospective study in a pediatric tertiary care facility. METHODS: A total of 54 cases (82 ears) of children with EVA were identified with complete records, including otologic evaluation, imaging studies, and audiologic assessments. The diagnosis of EVA was confirmed by computerized tomography scan/magnetic resonance imaging of the temporal bone. Hearing status was assessed using behavioral testing or auditory brainstem response (ABR). Tympanometry, acoustic reflex, and vestibular evoked myogenic potential (VEMP) testing were also performed when appropriate. RESULTS: Fifty-two percent of our EVA cases showed bilateral involvement, and 43% of all ears with EVA also had cochlear malformations, such as Mondini dysplasia. Sensorineural HL was initially diagnosed in 16 ears (20% of the total) with EVA whereas conductive or mixed HL was found in 66 ears (80% of the total). Further review of all EVA cases with sensorineural HL showed lack of proper bone conduction testing, so air-bone gaps were missed. Despite air-bone gaps in EVA ears, middle ear pressure and mobility were usually normal, along with present acoustic reflexes. VEMP responses were present with abnormally low thresholds. CONCLUSIONS: Air-bone gap(s) can be found in most ears with EVA if both air and bone conduction thresholds are properly tested. Normal tympanometry, presence of acoustic reflex and low threshold VEMP responses suggest that the air-bone gap in EVA is due to an inner ear anomaly, similar to the "third" labyrinthine window syndrome.

Imaging of congenital anomalies and acquired lesions of the inner ear.

Imaging of the temporal bone is under continous developement. In the recent decades the technical advances of magnetic resonance imaging and computed tomography have contributed to improved imaging quality in assessment of the temporal bone. Dedicated imaging protocols have been developed and are routinely employed in most institutions. However, imaging interpretation remains challenging, since the temporal bone is an anatomically highly complex region and most diseases of the inner ear occur with low incidence, so that even radiologists experienced in the field may be confronted with such entities for the first time. The current review gives an overview about symptoms and imaging appearance of malformations and acquired lesion of the inner ear.

SNP genome scanning localizes oto-dental syndrome to chromosome 11q13 and microdeletions at this locus implicate FGF3 in dental and inner-ear disease and FADD in ocular coloboma.

We ascertained three different families affected with oto-dental syndrome, a rare but severe autosomal-dominant craniofacial anomaly. All affected patients had the unique phenotype of grossly enlarged molar teeth (globodontia) segregating with a high-frequency sensorineural hearing loss. In addition, ocular coloboma segregated with disease in one family (oculo-oto-dental syndrome). A genome-wide scan was performed using the Affymetrix GeneChip10K 2.0 Array. Parametric linkage analysis gave a single LOD score peak of 3.9 identifying linkage to chromosome 11q13. Haplotype analysis revealed three obligatory recombination events defining a 4.8 Mb linked interval between D11S1889 and SNP rs2077955. Higher resolution mapping and Southern blot analysis in each family identified overlapping hemizygous microdeletions. SNP expression analysis and real-time quantitative RT-PCR in patient lymphoblast cell lines excluded a positional effect on the flanking genes ORAOV1, PPFIA1 and CTTN. The smallest 43 kb deletion resulted in the loss of only one gene, FGF3, which was also deleted in all other otodental families. These data suggest that FGF3 haploinsufficiency is likely to be the cause of otodental syndrome. In addition, the Fas-associated death domain (FADD) gene was also deleted in the one family segregating ocular coloboma. Spatiotemporal in situ hybridization in zebrafish embryos established for the first time that fadd is expressed during eye development. We therefore propose that FADD haploinsufficiency is likely to be responsible for ocular coloboma in this family. This study therefore implicates FGF3 and FADD in human craniofacial disease.

Audiological performance after cochlear implantation in children with inner ear malformations.

OBJECTIVES: To prove that cochlear implantation is a beneficial method of rehabilitation in deaf children with malformations of the inner ear. DESIGN: The evaluation of auditory responses to speech (EARS) test battery was performed on the children in this study after an average implant use of 3 years. RESULTS: Individual results of six children with inner ear anomalies receiving cochlear implants are presented in this study. Three of the patients showed an incomplete partition (Mondini dysplasia), one had a cochlear hypoplasia and two suffered from an intraoperative cerebrospinal fluid leak. The majority of the children in this study are successful implant users. Wherever possible, test scores are included and subjective case reports given. CONCLUSIONS: Results are similar to those in children with normal cochleas, therefore inner ear malformations found in as many as 20% of patients with congenital sensorineural hearing loss are no contraindication for cochlear implantation. Nevertheless, factors influencing the success of implantation are multiple, including a thorough preoperative radiological examination, a well-performed surgery and an individually tailored postoperative rehabilitation programme.