Cochlear Dysplasia Research Articles

The imaging appearances of stapical footplate fistula related to inner ear malformation

Objective: To summarize the HRCT and MRI appearances of stapical footplate fistula related to inner ear malformation (SFF-Re-IEM). Methods: The HRCT and MRI materials of 48 cases (53 ears) SFF-Re-IEM were retrospectively analyzed. Among them, 25 SFF-Re-IEM ears were confirmed by surgery. Their CT and MRI findings including associated IEM type, internal auditory canal (IAC) malformation, tympanic fluid, its density and signal features, and accompanied labyrinthitis were recorded. Results: Among 48 cases (53 ears) with SFF-Re-IEM, 17 ears with incomplete partition type Ⅰ, accounting for 32.1%, 13 ears with common cavity for 24.5%, 13 ears with cochlear aplasia for 24.5%, 7 ears with cochlear dysplasia Ⅱ for 13.2%, and 3 ears with Mondini for 5.7%,were found respectively. 94.3% of them were associated with a defect or dysplasia in the found of the IAC. They were divided into 4 types according to the intact of the stapical footplate and accompanied CSF otorrhea: 22 ears were diagnosed as the stapical footplate leaking, of them, 2 ears might come from the stapical footplate bony defect, 6 ears were from the stapical footplate hernia. 1 ear belonged to the peristapical footplate leaking. 30 ears with the isolated the stapical footplate hernia were another found. The bony defect in 2 ears with the stapical footplate bony defect were not presented on CT and MRI.The focal bony defect of the affected stapical footplate of 36 ears with the stapical footplate hernia were demonstrated, which presented the hemispherical protruding into the tympana, the soft-tissue density on CT, and CSF-like signal on the MR heaved-T2WI images. Among 22 ears with the stapical footplate leaking, their imaging appearances varied from the different amount of the leaking CSF. Besides the focal bony defects of the affected stapical footplates, there were much more CSF-like density or signal in the ipsilateral tympanic cavity in 17 affected ears connecting with the vestibule through the defect area. In the CSF leaking ears with less CSF leaking in 5 ears, the CSF-like cysts like SFH were shown on the stapical footplate defect area, but their outer edges were irregular, and the CSF-like signal scattering in the tympanic cavity did not connect with the protruding cysts at the stapical area. Conclusion: The variable appearances of the SFF-Re-IEM ears based on the different subtypes are its characteristic HRCT and MRI appearances. This is helpful for the SFF-Re-IEM diagnosing to grasp its imaging features.

Clinical features and temporal CT findings in patients with Branchio-Oto-Renal or Branchio-Oto Syndrome

Objective: To assess the clinical features and CT diagnostic characteristics of Branchio-Oto-Renal or Branchio-Oto Syndrome. Methods: The temporal CT findings and clinical features observations of 13 patients with Branchio-Oto-Renal Syndrome (BORS) or Branchio-Oto Syndrome(BOS) confirmed by genetic testing were retrospectively analyzed. There were 8 males and 5 females, aged from 1 to 39 years, with a median age of 9 years, in which 3 pairs (6 cases) were parent-child relationship. Results: All of 13 cases had hearing loss and preauricular fistula, 11 cases accompanied by 2nd branchial fistulas. There were 20 ears of mixed hearing loss, 3 ears of sensorineural hearing loss, and 2 ears of conductive hearing loss. The mutation point of gene testing was located in EYA1 in 12 cases and SIX1 in 1 case. Twenty ears showed gradually narrowing of the diameter of basal turn, with hypoplasia in the second turn and aplasia in apical turn. There were irregular wall of vestibule and horizontal semicircular canal in 10 ears,widened vestibular in 7 ears, and vestibular fusion with horizontal semicircular canal in 3 ears. Three ears had an enlarged vestibular aqueduct, 8 ears showed enlargement of internal auditory canal. Seventeen ears had adhesion of malleolus to tympanic cavity. Six ears could not measured the incudostapedial joint angle by reason of tympanic inflammatory cover, 3 ears could not show incudostapedial joint, and 8 ears showed the incudostapedial joint angle more than 122°. Six ears showed poor oval window, and 1 ear had poor round window. Eighteen ears showed distended eustachian tube, and accompanied by tympanic or mastoiditis in 11 ears. Anterolateral shift of tympanum was found in 22 ears, 17 ears had low middle cranial fossa, and 3 ears had stenotic external auditory canal. Conclusions: Cochlear dysplasia, ossicular chain malformation and distended eustachian tube comprise the characteristic CT signs of BOS/BORS, which possesses versatile and complex CT findings. Temporal CT can accurately assess the important structures such as cochlea, ossicles, vestibule, semicircular canal, vestibular aqueduct and internal auditory canal. Combing with the clinical characteristics of bilateral, mixed hearing loss, preauricular fistula and branchial fistula can provide valuable information for early diagnosis and treatment.

Hearing characteristics and otoradiological abnormalities in three patients with novel pathogenic variants of KMT2D-related Kabuki syndrome.

Kabuki syndrome 1 (KS1; OMIM:147920), which is characterized by distinctive dysmorphic facial features (such as arched eyebrows, long palpebral fissures with eversion of the lower lid, and large protuberant ears), intellectual disability, short stature, and dermatoglyphic and skeletal abnormalities, is brought on by pathogenic variants in KMT2D (OMIM:602113). In this work, three individuals with novel pathogenic KMT2D gene variants had their longitudinal audiological manifestations and ear structural characteristics outlined. The longitudinal audiological data from neonatal hearing screening and a battery of several hearing tests were evaluated. The battery of hearing tests included tympanometry, distortion product otoacoustic emission (DPOAE), click-evoked air-conduction auditory brain-stem response (AC-ABR), click-evoked bone-conduction auditory brain-stem response (BC-ABR), narrow band CE-chirp auditory steady-state response (NB CE-chirp ASSR), and pure-tone audiometry (PTA). Phenotype identification and whole exome sequencing (WES) were performed on recruited individuals. All three patients (two females and on male; last evaluations at 14 months, 11 months, and 5.7 years, respectively) failed the newborn hearing screening, and the audiological follow-up data revealed mild to profound fluctuating hearing loss, which was directly influenced by the incidence and severity of otitis media with effusion (OME). When OME occurred, the AC-ABR thresholds increased from 30-75 dBnHL to 45-90 dBnHL. The threshold for the BC-ABR and BC-PTA was between 25 and 50 dBnHL, indicating mild to moderate sensorineural hearing loss (SNHL). The high-resolution computed tomography (HRCT) pictures indicated that all three patients had middle and inner ear abnormalities. Middle ear anomalies showed as diminished mastoid gasification and ossicle dysplasia. Cochlear dysplasia, a dilated vestibule, fusion of the vestibule with the horizontal semicircular canals, and a short and thick horizontal semicircular canal were visible on images of the inner ear. This study recruited three individuals with three novel pathogenic variants (c.5104C>T, c.10205delA, and c.12840delC) of KMT2D who were identified at ages 27 days, 2 months, and 5.5 years. Hearing characteristics of three individuals with three novel pathogenic variants of KMT2D range from mild to profound fluctuating hearing loss with mild to moderate SNHL. HRCT scans showed that all three individuals had anatomical middle and inner ear abnormalities. KS 1 patients must get clinical therapy for OME, frequent auditory monitoring, and prompt intervention.

The Prevalence of Hearing Aid Use in Children With Single-Sided Sensorineural Deafness in Oxfordshire

The Prevalence of Hearing Aid Use in Children With Single-Sided Sensorineural Deafness in Oxfordshire

Cochlear implantation in patients with Pendred syndrome

ObjectiveTo examine the outcomes of cochlear implantation in children with Pendred Syndrome. Material and methodsA retrospective case series of nine pediatric patients with Pendred syndrome undergoing cochlear implantation at a tertiary academic medical center from 2003 to 2017. ResultsAll patients were diagnosed with bilateral mild-to-profound to severe-to-profound sensorineural hearing loss and used hearing aids prior to implantation. Preoperative imaging results revealed that all patients exhibited bilateral enlarged vestibular aqueducts and 8 of 9 had cochlear dysplasia equivalent to Incomplete Partition II. Despite inner ear malformations, all electrodes were successfully implanted with minimal complications and favorable post-operative audiological outcomes. ConclusionsCochlear implantation is an effective and successful treatment for severe-to-profound hearing loss in children with Pendred syndrome and for whom traditional amplification aids provide limited benefit. With early intervention, cochlear implantation allows speech and cognitive development in Pendred children comparable to that of normal hearing individuals, allowing patients to learn in a mainstream educational setting.

An analysis of surgical management of difficulties during cochlear implant with inner ear anomalies

Objective:The purpose of this study is to review the difficulties that can occur during cochlear implant surgery in patients with inner ear abnormalities and the management. Method:A retrospective analysis was made on 186 cases of cochlear implant with inner ear malformation, the types of inner ear malformations included 6 cases（3.23%） of isolated semicircular dysplasia, 137 cases（73.66%） of isolated large vestibular aqueducts, 26 cases（13.98%） of Mondini malformations, 6 cases（3.23%） of incomplete septal type Ⅲ, 3 cases（1.61%） of internal auditory stenosis, 7 cases（3.76%） of cochlear dysplasia and 1 case（0.54%） of incomplete septal typeⅠ. Two hundred patients with normal inner ear structures were randomly selected as the control group. The data collected included the types of inner ear abnormalities, intraoperative manifestations, clinical management strategies, and postoperative speech rehabilitation, and the literature was reviewed. Result:148 patients（77.49%） with inner ear malformation underwent successful surgery, electrode insertion was incomplete in 6 patients（3.14%）, and cerebrospinal fluid blowout occurred in 29 patients（15.18%）, it was difficult to locate the window because of the abnormal structure of the window in 8 cases（4.19%）. In 191 patients, the facial recess approach was adopted intraoperatively, and 17.8% of the patients had significant structural abnormalities of the facial nerve, significantly more than the group with normal inner ear structure. Only 1 patient showed delayed facial nerve paralysis 1 week after surgery, and recovered well after treatment. 6.81% of the patients adopted the expanded round window approach, which was significantly lower than that of the group with normal inner ear structure（28%）. There was no significant difference between patients with inner ear malformation and patients with extremely severe deafness with normal inner ear structure who received cochlear implant in speech rehabilitation. Conclusion:Cochlear implant is safe, feasible and effective for patients with inner ear malformation. For patients with inner ear malformation, special attention should be paid to the preoperative imaging reading to predict the possible risks during the operation. The safest surgical plan, including the type of electrode and the manner in which the window is opened, must be prepared before the operation, and the operation must be performed or directed by an experienced surgeon who can adjust the optimal surgical plan according to what is seen during the operation.

Imaging findings in pediatric single-sided deafness and asymmetric hearing loss.

To examine the imaging findings on computer tomography (CT) and magnetic resonance imaging (MRI) in pediatric single-sided deafness (SSD) and asymmetric hearing loss (ASH). The medical records of 189 pediatric patients with SSD and ASH were retrospectively reviewed, and imaging findings were compared. SSD was defined as unilateral profound hearing loss and contralateral normal hearing ear. In the ASH group, ASHw was defined as the worse hearing ear with profound hearing loss, while ASHb was defined as the better hearing ear with mild-moderate hearing loss. There were 170 patients with SSD and 19 patients with ASH. In the SSD group, 83 patients (48.8%) had imaging findings associated with hearing loss. In the ASH group, such imaging findings were found in six (31.6%) of the ASHw and in five (26.3%) of the ASHb ears. The most common finding in the SSD group was cochlear nerve deficiency (50.6%), followed by cochlear dysplasia (39.8%) and enlarged vestibular aqueduct (26.5%). In the ASH groups, cochlear dysplasia was seen in three (50%) of ASHw ears and in two (40%) of the ASHb ears, and enlarged vestibular aqueduct was seen in three (50%) of ASHw ears and in two (40%) of the ASHb ears. Imaging studies identified the etiology in half of the cases of SSD and in one-third of ASH patients. Our findings strongly support the use of imaging studies in the evaluation of pediatric SSD and ASH. 4 Laryngoscope, 130:1007-1010, 2020.

The Modified Rambo Transcanal Approach for Cochlear Implantation in CHARGE Syndrome.

CHARGE syndrome is associated with a variety of temporal bone anomalies and deafness. The lack of surgical landmarks and facial nerve irregularities make cochlear implantation in this population a challenging endeavor. This study aims to describe a safe and efficacious transcanal approach for cochlear implantation that obviates the need to perform a mastoidectomy and facial recess. Three children with profound hearing loss secondary to CHARGE syndrome. Transcanal cochlear implantation with closure of the ear canal via a modified Rambo meatoplasty. Retrospective chart review of temporal bone anomalies associated with CHARGE syndrome, technical nuances of this transcanal approach, and cochlear implant outcomes. The mean patient age was 2.5 years (range 1.5-3.8 yr). Two were male and two were left ears. All patients had a hypoplastic mastoid, semicircular canal aplasia, and had some degree of cochlear dysplasia. A full cochlear implant insertion was achieved in all cases, even in the presence of grossly abnormal middle ear and facial nerve anatomy. There were no intraoperative or postoperative complications. The mean follow-up was 12.4 months (range, 3.9-25.2 mo). All three patients use their device daily. Their guardians report improved vocalization and environmental awareness. The modified Rambo transcanal approach provides a safe corridor for cochlear implantation in patients with CHARGE syndrome. This approach minimizes the anatomical variations associated with the syndrome and may reduce the risk of electrode extrusion. Implant outcomes in this patient population remain highly variable based on the patient's global cognitive capacity.

Clinical outcomes following cochlear implantation in children with inner ear anomalies

ObjectiveA 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. MethodsThe 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. ResultsThe 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%). ConclusionsCochlear 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.

Evaluation of embryological sequences of ear anomalies and its radiological relevance

Aim: To correlate the sequence of embryological development of ear with radiological imaging. Materials and Methods: The study enrolled 23 patients of age group 11 months to 27 years with malformed external ear/microtia and hearing loss. The children with postoperative changes, acute hearing loss (such as infection, trauma) were excluded from the study. We used high-resolution computed tomography, with axial and coronal sections to examine the temporal bones of patients. Results: Of the 23 cases, 12 cases had external ear anomaly and 11 cases had cochlear anomaly. In patients with the external ear anomaly, seven cases had associated middle ear malformations, one patient had associated middle and inner ear anomaly, one had anomalous course of facial nerve, and three cases had isolated external ear anomalies. In patients with inner ear anomalies, one patient had complete labyrinthine aplasia, one had cochlear dysplasia with incomplete cochlear turns, four had common cavity malformations, one had cystic featureless cochlea with dilated and cystic vestibule, two patients had small cochlea with the middle and apical turns coalescing to form a cystic apex, one patient had small rudimentary cochlea, and the other one had dilated vestibule and enlarged endolymphatic duct and sac with cochlear dysmorphism. Conclusion: Most of the children with malformed pinna had external auditory canal atresia with associated middle ear anomalies. Though the inner ear development is independent of external and middle ear development, we insist on the fact that insult during the 1 st month of embryogenesis can result in associated abnormalities involving external, middle, and inner ear. Developmental arrest at various stages of inner ear development results in various types of cochlear anomalies with associated vestibular, semicircular canal abnormalities, and rarely associated with middle and external ear anomalies. Hence, clear knowledge about embryology will help to guide the management.

Ganglion cell populations in normal and pathological human cochleae. Implications for cochlear implantation. 1978.

A histological study of 100 hearing ears showed that some capability for speech discrimination requires at least 10,000 spiral ganglion cells. The spiral ganglion cell populations were then estimated in another group of 62 ears which were profoundly deaf for a variety of causes and it was found that 45% of these met the criterion of having 10,000 ganglion cells. The ganglion cell populations were largest in ears deafened by sudden deafness, Meniere's Disease, and ototoxic drugs; they were somewhat less for those with vascular occlusion, temporal bone fracture, otosclerosis, and cochlear dysplasias; they were least in those with measles, bacterial labyrinthitis and congenital syphilis. The data is of relevance in the selection of patients for cochlear implantation.

Imaging Evaluation of Pediatric Sensorineural Hearing Loss in Potential Candidates for Cochlear Implantation.

Computerized tomography (CT) and magnetic resonance (MR) are complementary in the imaging of the labyrinth, the internal auditory canal and the brain in children with sensorineural hearing loss who are being evaluated for cochlear implantation. An accurate anatomical description of the inner ear is essential in the preoperative work up. Computerized tomography visualizes the bony structures, whereas MR can discern soft-tissue components including intra labyrinthine fluid, cerebrospinal fluid (CSF), nerves, and vessels within the IAC. This prospective study was conducted in the Department of Otorhinolaryngology, Head & Neck Surgery, Government Medical College, Srinagar. 40 children in the age group of 1-16years with unidentified causes of bilateral SNHL were analysed radiologically over the period of 2years from Dec 2011 to Jan 2014. Each patient underwent MRI and high resolution CT scanning of temporal bone in axial and coronal planes. Out of the 40 patients 22 were males (55%) and 18 were females (45%). 30 patients (72.5%)in our study had normal radiological scans. Five patients (12.5%) had B/L large vestibular aqueduct and two patients (5%) had internal auditory canal stenosis with cochlear nerve hypoplasia on CT and MR imaging. Cochlear dysplasia was present in two patients (5%) and semicircular canal dysplasia was present in one patient (2.5%) as an isolated finding on HRCT. In addition isolated cochlear nerve hypoplasia was present in one patient (2.5%). Hyperintense basal ganglia lesion suggestive of kernicterus was present in one patient (2.5%) and hyperintense posterior parietal and occipital white matter lesions suggestive of congenital CMV infection was present in one patient (2.5%) on MR imaging. Arachnoid cysts of middle cranial fossa was an incidental finding present in one patient. Radiological abnormalities of the inner ear are not uncommon. Computerized tomography and MRI are important modalities to analyze the inner ear in children with unexplained SNHL. MRI with an extremely small field of view should be used to study possible abnormalities of the vestibulocochlear nerves.

Barriers to early pediatric cochlear implantation

ObjectivesUniversal newborn hearing screening has significantly improved the ability to identify patients with congenital sensorineural hearing loss (SNHL), which results in earlier treatment and better hearing and development outcomes. It is recommended that patients born with SNHL who meet criteria receive cochlear implants (CIs) by a target age of 12 months, however many children are being implanted at an older age. This study aims to describe populations of pre-lingual patients with SNHL that are at risk for delayed implantation and to identify and analyze barriers that cause this delay. MethodsCharts of patients receiving a CI between January 2008 and June 2012 at a tertiary care cochlear implant center were reviewed retrospectively. We looked at patient demographics, age at hearing loss diagnosis, age at implantation, and etiology of hearing loss. Barriers to implantation were identified through surveys completed by team members. ResultsFifty-seven CI recipients were identified of which 42 were in patients with pre-lingual SNHL. SNHL etiology included: cochlear dysplasia (18%), GJB2/GJB6 (17%), acquired (10%) extreme prematurity (9%), and idiopathic (46%). The median age of SNHL diagnosis for pre-lingual patients was 15 months. Compared to private insurance, public insurance status was associated with SNHL diagnosis at a significantly later median age (20.0 vs. 4.0 months, p=0.024), and with a significantly longer median interval from diagnosis to implantation (25.5 vs. 11.0 months, p=0.029). While cochlear implant team members identified delayed insurance approval and medical comorbidities as reasons for delayed implantation, the most significant factor identified was parental, with delayed/missed appointments or reluctance for evaluations or surgery. Conclusion52% of patients with pre-lingual SNHL that met criteria for CI were implanted more than 12 months after diagnosis. Having public or no insurance was significantly associated with delayed implantation. Parental barriers were most common factors cited for delays in implantation. Overcoming these delays necessitates appropriate identification of at risk patients and creating a system to educate families and chaperone them through the process.

Cochlear implant: what the radiologist should know

Cochlear implant is the method of choice in the treatment of deep sensorineural hypoacusis, particularly in patients where conventional amplification devices do not imply noticeable clinical improvement. Imaging findings are crucial in the indication or contraindication for such surgical procedure. In the assessment of the temporal bone, radiologists should be familiar with relative or absolute contraindication factors, as well as with factors that might significantly complicate the implantation. Some criteria such as cochlear nerve aplasia, labyrinthine and/or cochlear aplasia are still considered as absolute contraindications, in spite of studies bringing such criteria into question. Cochlear dysplasias constitute relative contraindications, among them labyrinthitis ossificans is highlighted. Other alterations may be mentioned as complicating agents in the temporal bone assessment, namely, hypoplasia of the mastoid process, aberrant facial nerve, otomastoiditis, otosclerosis, dehiscent jugular bulb, enlarged endolymphatic duct and sac. The experienced radiologist assumes an important role in the evaluation of this condition.

Xq26.3 Microdeletion in a Male with Wildervanck Syndrome

ABSTRACTBackground: Wildervanck Syndrome (WS; cervico-oculo-acoustic syndrome) consists of Duane retraction syndrome (DRS), the Klippel-Feil anomaly, and congenital deafness. It is much more common in females than males and could be due to an X-linked mutation that is lethal to hemizygous males. We present the genetic evaluation of a male with WS and his family.Materials and Methods: Clinical evaluation and neuroimaging, sequencing of candidate genes, and array comparative genomic hybridization.Results: The patient had bilateral type 1 DRS, fusion of almost the entire cervical spine, and bilateral severe sensorineural hearing loss due to bilateral cochlear dysplasia; he also had congenital heart disease requiring surgery. His parents were unrelated, and he had eight unaffected siblings. The patient had no mutation found by Sanger sequencing of HOXA1, KIF21A, SALL4, and CHN1. He had a 3kB deletion in the X-chromosome at Xq26.3 that was not found in his mother, one unaffected sibling, or 56 healthy controls of matching ethnicity. This deletion encompassed only one gene, Fibroblast Growth Factor Homologous Factor 13 (FGF13), which encodes a 216-amino acid protein that acts intracellularly in neurons throughout brain development.Conclusions: Analysis of this patient’s phenotype and genotype open the possibility that X-chromosome deletions may be a cause of WS with larger deletions being lethal to males and that FGF13 mutations may be a cause of WS.

A case of palmoplantar lichen planus in a patient with congenital sensorineural deafness

We report a case of palmoplantar lichen planus in a 7-year-old Japanese girl with congenital deafness, who presented with erythematous eruptions and hyperkeratosis, with peeling and fissures on her soles, palms and digits. On histological examination of a skin biopsy from the lesion on her wrist, lichen planus was identified. Using computed tomography of the inner ears, bilateral cochlear dysplasia was found. The patient's DNA was sequenced; no sequence variants were detected in the GJB2 gene encoding connexin-26, but she had a missense mutation in SLC26A4 (solute carrier family 26, member 4). Mutations in SLC26A4 are known causes of hearing loss, but this is a novel mutation, which has not been reported previously. In addition, there have been no reports of cutaneous symptoms in previously reported patients with mutations in SLC26A4. To our knowledge, therefore, this is the first report of palmoplantar lichen planus associated with sensorineural deafness accompanied by a mutation in the SLC26A4 gene.

Simultaneous cerebrospinal fluid otorrhea and rhinorrhea as a cause of recurrent meningitis in a patient with cochlear dysplasia

Inner ear dysplasia is a rare cause of cerebrospinal fluid otorhinorrhea and presents in a variety of ways, ranging from asymptomatic to recurrent bacterial meningitis. We describe a 6-year-old boy who presented with clear watery nasal discharge and recurrent bacterial meningitis. Magnetic resonance cisternogram showed cerebrospinal fluid leak through the cribriform plate of ethmoid. High-resolution computed tomographic scan of temporal bones confirmed the diagnosis of cochlear dysplasia, with cerebrospinal fluid leak coming through a defect near the oval window and through the eustachian tube orifice into the nose. Surgical closure of the defects was performed successfully. Recurrent meningitis in a child should be investigated for inner ear malformations. Awareness of this condition, a high index of suspicion and early imaging can prevent complications and give excellent results in these children.

Pontine Tegmental Cap Dysplasia

Pontine tegmental cap dysplasia (PTCD) is a rare congenital malformation. Clinical and imaging findings in 3 patients and the authors' experience with bilateral cochlear implantation in 1 patient are described. Retrospective review. Two tertiary medical centers. Three patients were evaluated by an otolaryngologist and underwent magnetic resonance imaging (MRI) of the temporal bones and brain. High-resolution computed tomography (CT) scanning of the temporal bones was performed in 2 patients. Imaging findings of the brain, the presence and course of resolvable cranial nerves, the membranous labyrinth, and internal auditory canals were reviewed. Clinical data were reviewed. All patients demonstrated typical brain characteristics of PTCD. Mild, bilateral cochlear dysplasia was noted in 2, and all had a normal vestibular labyrinth. The cochleovestibular nerves were universally absent bilaterally. The facial nerves were subjectively deficient bilaterally in 1 patient, unilaterally in the second patient, and normal in the third. An accessory canal for the seventh cranial nerve, referred to as a duplicated internal auditory canal, was present in all patients. Auditory brainstem response testing revealed profound bilateral sensorineural hearing loss in all of the patients; none suffered facial weakness. A single patient underwent bilateral cochlear implantation with only minimal response. The authors report 3 cases of PTCD with emphasis on imaging of the seventh and eighth cranial nerves and clinical neurotologic findings. All patients manifested duplicated internal auditory canals, a previously unreported finding in PTCD. Bilateral profound sensorineural hearing loss is due to absence of the cochleovestibular nerve. Prognosis for cochlear implantation is poor.

Recurrent meningitis via a cerebrospinal fluid fistula with cochlear dysplasia in a child

Recurrent meningitis via a cerebrospinal fluid fistula with cochlear dysplasia in a child

Current Status of Bacterial Meningitis After Cochlear Implantation

Meningitis after cochlear implantation continues to be a concern. Recent studies and anecdotal reports support the belief that intracochlear trauma, lack of appropriate immunizations, and a previously used dual-component electrode predispose patients to a higher rate of contracting meningitis. In addition, a history of meningitis, cochlear dysplasia, and certain variations of surgical technique such as the cochleostomy, very young age, immunocompromise, and the presence of neural prostheses such as shunts, are all potentially predisposing factors. Because many of these factors are beyond our control, there is likely to be an inevitable baseline incidence of meningitis, perhaps related to the underlying deafness, but by controlling other factors, we can hope to minimize the incidence. Despite the efforts of multiple individuals and organizations, there continue to be new cases of meningitis, including a small number of fatalities, each year. There is recent evidence that a sizeable percentage of children with implants have not been vaccinated as suggested by governmental agencies, otolaryngologic societies, implant manufacturers, and many cochlear implant centers. Clearly, efforts must be made to ensure age-appropriate vaccination for all cochlear implant recipients.