Recurrent missense variant identified in two unrelated families with MPZL2-related hearing loss, expanding the variant spectrum associated with DFNB111.

MPZL2-related hearing loss is a rare form of autosomal recessive hearing loss characterized by progressive, mild sloping to severe sensorineural hearing loss. Thirty-five previously reported patients had biallelic truncating variants in MPZL2, with the exception of one patient with a missense variant of uncertain significance and a truncating variant. Here, we describe the clinical characteristics and genotypes of five patients from four families with confirmed MPZL2-related hearing loss. A rare missense likely pathogenic variant [NM_005797.4(MPZL2):c.280C>T,p.(Arg94Trp)] located in exon 3 was confirmed to be in trans with a recurrent pathogenic truncating variant that segregated with hearing loss in three of the patients from two unrelated families. This is the first recurrent likely pathogenic missense variant identified in MPZL2. Apparently milder or later-onset hearing loss associated with rare missense variants in MPZL2 indicates that some missense variants in this gene may cause a milder phenotype than that resulting from homozygous or compound heterozygous truncating variants. This study, along with the identification of truncating loss of function and missense MPZL2 variants in several diverse populations, suggests that MPZL2-related hearing loss may be more common than previously appreciated and demonstrates the need for MPZL2 inclusion in hearing loss testing panels.

Comprehensive Gene Panel Testing for Hearing Loss in Children: Understanding Factors Influencing Diagnostic Yield.

OBJECTIVE: To evaluate factors influencing the diagnostic yield of comprehensive gene panel testing (CGPT) for hearing loss (HL) in children and to understand the characteristics of undiagnosed probands. STUDY DESIGN: This was a retrospective cohort study of 474 probands with childhood-onset HL who underwent CGPT between 2016 and 2020 at a single center. Main outcomes and measures included the association between clinical variables and diagnostic yield and the genetic and clinical characteristics of undiagnosed probands. RESULTS: The overall diagnostic yield was 44% (209/474) with causative variants involving 41 genes. While the diagnostic yield was high in the probands with congenital, bilateral, and severe HL, it was low in those with unilateral, noncongenital, or mild HL; cochlear nerve deficiency; preterm birth; neonatal intensive care unit admittance; certain ancestry; and developmental delay. Follow-up studies on 49 probands with initially inconclusive CGPT results changed the diagnostic status to likely positive or negative outcomes in 39 of them (80%). Reflex to exome sequencing on 128 undiagnosed probands by CGPT revealed diagnostic findings in 8 individuals, 5 of whom had developmental delays. The remaining 255 probands were undiagnosed, with 173 (173/255) having only a single variant in the gene(s) associated with autosomal recessive HL and 28% (48/173) having a matched phenotype. CONCLUSION: CGPT efficiently identifies the genetic etiologies of HL in children. CGPT-undiagnosed probands may benefit from follow-up studies or expanded testing.

Perspective on the Development of a Large-Scale Clinical Data Repository for Pediatric Hearing Research.

The use of "big data" for pediatric hearing research requires new approaches to both data collection and research methods. The widespread deployment of electronic health record systems creates new opportunities and corresponding challenges in the secondary use of large volumes of audiological and medical data. Opportunities include cost-effective hypothesis generation, rapid cohort expansion for rare conditions, and observational studies based on sample sizes in the thousands to tens of thousands. Challenges include finding and forming appropriately skilled teams, access to data, data quality assessment, and engagement with a research community new to big data. The authors share their experience and perspective on the work required to build and validate a pediatric hearing research database that integrates clinical data for over 185,000 patients from the electronic health record systems of three major academic medical centers.

Temporal bone radiology report classification using open source machine learning and natural langue processing libraries.

BACKGROUND: Radiology reports are a rich resource for biomedical research. Prior to utilization, trained experts must manually review reports to identify discrete outcomes. The Audiological and Genetic Database (AudGenDB) is a public, de-identified research database that contains over 16,000 radiology reports. Because the reports are unlabeled, it is difficult to select those with specific abnormalities. We implemented a classification pipeline using a human-in-the-loop machine learning approach and open source libraries to label the reports with one or more of four abnormality region labels: inner, middle, outer, and mastoid, indicating the presence of an abnormality in the specified ear region. METHODS: Trained abstractors labeled radiology reports taken from AudGenDB to form a gold standard. These were split into training (80 %) and test (20 %) sets. We applied open source libraries to normalize and convert every report to an n-gram feature vector. We trained logistic regression, support vector machine (linear and Gaussian), decision tree, random forest, and naïve Bayes models for each ear region. The models were evaluated on the hold-out test set. RESULTS: Our gold-standard data set contained 726 reports. The best classifiers were linear support vector machine for inner and outer ear, logistic regression for middle ear, and decision tree for mastoid. Classifier test set accuracy was 90 %, 90 %, 93 %, and 82 % for the inner, middle, outer and mastoid regions, respectively. The logistic regression method was very consistent, achieving accuracy scores within 2.75 % of the best classifier across regions and a receiver operator characteristic area under the curve of 0.92 or greater across all regions. CONCLUSIONS: Our results indicate that the applied methods achieve accuracy scores sufficient to support our objective of extracting discrete features from radiology reports to enhance cohort identification in AudGenDB. The models described here are available in several free, open source libraries that make them more accessible and simplify their utilization as demonstrated in this work. We additionally implemented the models as a web service that accepts radiology report text in an HTTP request and provides the predicted region labels. This service has been used to label the reports in AudGenDB and is freely available.

Macrophage migration inhibitory factor acts as a neurotrophin in the developing inner ear.

This study is the first to demonstrate that macrophage migration inhibitory factor (MIF), an immune system 'inflammatory' cytokine that is released by the developing otocyst, plays a role in regulating early innervation of the mouse and chick inner ear. We demonstrate that MIF is a major bioactive component of the previously uncharacterized otocyst-derived factor, which directs initial neurite outgrowth from the statoacoustic ganglion (SAG) to the developing inner ear. Recombinant MIF acts as a neurotrophin in promoting both SAG directional neurite outgrowth and neuronal survival and is expressed in both the developing and mature inner ear of chick and mouse. A MIF receptor, CD74, is found on both embryonic SAG neurons and adult mouse spiral ganglion neurons. Mif knockout mice are hearing impaired and demonstrate altered innervation to the organ of Corti, as well as fewer sensory hair cells. Furthermore, mouse embryonic stem cells become neuron-like when exposed to picomolar levels of MIF, suggesting the general importance of this cytokine in neural development.

Children With Sensorineural Hearing Loss And Referral To Early Intervention.

OBJECTIVE: Sensorineural hearing loss (SNHL) is identified at a rate of 1-3 per 1,000 newborns in the United States. Timely referral to Early Intervention (EI) services is critical, as early EI referral has been shown to improve outcomes, including speech and language development, social and emotional development, and academic performance. The objective of this study was to determine the rate at which children diagnosed with SNHL at a large tertiary referral center were referred to EI, and, if so, by whom. In addition, we sought to determine the time from the diagnosis of SNHL to the completion of the referral, and what services were received. DESIGN: Prospective observational study METHODS: Data were collected by telephone survey and review of the electronic medical record RESULTS: Children with SNHL were referred to and participated in EI at a high rate. All children in this study (100%) were referred to EI. Most (92%) of the children were referred by 6 months of age, and almost all (98%) participated in EI. CONCLUSION: At our institution, children with SNHL are being consistently referred to EI, meeting the goals of the Early Hearing Detection and Intervention program. Future outcomes research can now be designed to determine whether achieving these benchmark goals improves children's academic performance, expressive and receptive language skills, and development as compared to age-matched, normal hearing peers.

Congenital Cytomegalovirus Testing Outcomes From the ValEAR Trial.

OBJECTIVE: To determine the positivity rate of congenital cytomegalovirus (cCMV) testing among universal, hearing-targeted CMV testing (HT-cCMV) and delayed targeted dried blood spot (DBS) testing newborn screening programs, and to examine the characteristics of successful HT-cCMV testing programs. STUDY DESIGN: Prospective survey of birth hospitals performing early CMV testing. SETTING: Multiple institutions. METHODS: Birth hospitals participating in the National Institutes of Health ValEAR clinical trial were surveyed to determine the rates of cCMV positivity associated with 3 different testing approaches: universal testing, HT-cCMV, and DBS testing. A mixed methods model was created to determine associations between successful HT-cCMV screening and specific screening protocols. RESULTS: Eighty-two birth hospitals were surveyed from February 2019 to December 2021. Seven thousand six hundred seventy infants underwent universal screening, 9017 infants HT-cCMV and 535 infants delayed DBS testing. The rates of cCMV positivity were 0.5%, 1.5%, and 7.3%, respectively. The positivity rate for universal CMV screening was less during the COVID-19 pandemic than that reported prior to the pandemic. There were no statistically significant drops in positivity for any approach during the pandemic. For HT-cCMV testing, unique order sets and rigorous posttesting protocols were associated with successful screening programs. CONCLUSION: Rates of cCMV positivity differed among the 3 approaches. The rates are comparable to cohort studies reported in the literature. Universal CMV prevalence decreased during the pandemic but not significantly. Institutions with specific order set for CMV testing where the primary care physician orders the test and the nurse facilitates the testing process exhibited higher rates of HT-cCMV testing.

High-Dose Celecoxib for Pain After Pediatric Tonsillectomy: A Randomized Controlled Trial.

OBJECTIVE: Pediatric tonsillectomy causes significant postoperative pain. Newer nonsteroidal anti-inflammatory drugs such as celecoxib control pain without increasing bleeding risk, but in prior studies provided only modest pain reduction at standard doses. We aimed to determine if high-dose celecoxib (double the usual pediatric dose) is effective for pain, without increasing bleeding or other risks. STUDY DESIGN: Randomized double-blind trial. SETTING: Pediatric tertiary center. METHODS: Children aged 3 to 11 years undergoing total tonsillectomy were randomized to receive celecoxib (6 mg/kg/dose) or placebo, twice daily, for up to 10 days. All cases were supplemented with acetaminophen and oxycodone as needed. All participants and personnel were blinded to treatment group. Subjects recorded coanalgesic consumption, pain, diet, and activity. RESULTS: The celecoxib group (n = 68) consumed 0.72 mg/kg of oxycodone, as compared with 1.12 mg/kg in the placebo group (n = 62), a 36% difference that was not significant. However, multivariate analysis by treatment group, separate from pain levels, confirmed that this reduction was due to celecoxib treatment (P = .03). In subjects with more prolonged pain (n = 88), celecoxib reduced consumption by 52% (P = .02). Celecoxib showed greater benefit for subjects in the prolonged pain group than for those in the lesser pain group (P = .006). Incidence of adverse events was similar between groups. Minor hemorrhage occurred in 4.6% (5 placebo, 3 celecoxib). CONCLUSION: High-dose celecoxib is effective in controlling pain after tonsillectomy, with no adverse effects in this relatively small sample. It reduces narcotic consumption, and its impact appears greater in children with higher degrees of pain. Celecoxib can be considered an effective alternative to ibuprofen after tonsillectomy. This trial was registered at ClinicalTrials.gov: NCT02934191.

Association of Diet Patterns and Post-Operative Tympanostomy Tube Otorrhea: A Pilot Study.

OBJECTIVE: The objective of this study was to explore diet patterns in children with tympanostomy tube placement (TTP) complicated by postoperative tympanostomy tube otorrhea. STUDY DESIGN: Cross-sectional survey and retrospective cohort study. METHODS: Caregivers of children (0-12 years old), at a tertiary-care pediatric hospital who underwent TTP within 6 months to 2 years prior to enrollment were included. Children with a history of Down syndrome, cleft palate, craniofacial syndromes, known immunodeficiency, or a non-English-speaking family were excluded. Our primary outcome variable was the number of otorrhea episodes. The primary predictor was diet patterns, particularly dessert intake, which was captured through a short food questionnaire. RESULTS: A total of 286 participants were included in this study. The median age was 1.8 years (IQR, 1.3, 2.9). A total of 174 (61%) participants reported at least one episode of otorrhea. Children who consumed dessert at least two times per week had a higher risk of otorrhea compared to children who consumed one time per week or less (odds ratio [OR], 3.22, 95% Confidence Interval [CI]: 1.69, 6.12). The odds ratio increase continued when considering more stringent criteria for otorrhea (multiple episodes or one episode occurring 4 weeks after surgery), with a 2.33 (95% CI: 1.24, 4.39) higher odds of otorrhea in children with dessert intake at least 2 times per week. CONCLUSIONS: Our pilot data suggest that episodes of otorrhea among children with TTP were associated with more frequent dessert intake. Future studies using prospectively administered diet questionnaires are necessary to confirm these findings. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:3575-3581, 2023.

Audiologic Phenotype and Progression in Pediatric STRC-Related Autosomal Recessive Hearing Loss.

OBJECTIVES: Sensorineural hearing loss (SNHL) is a common sensory deficit affecting pediatric populations. The majority of pediatric SNHL is genetic in etiology, with over 123 identified nonsyndromic causative genes. One such gene is STRC, which has been identified as the second most frequent autosomal recessive nonsyndromic gene associated with SNHL in multiple populations. The objective of this study was to investigate the phenotypic presentation and incidence of audiologic progression in pediatric patients with STRC-related hearing loss (HL). METHODS: Thirty-nine pediatric patients with confirmed HL and biallelic pathogenic STRC mutations were identified at two pediatric hospitals. A retrospective chart review was completed including demographics, medical history, genetic testing results, and audiologic data. HL progression was assessed using air conduction thresholds from pure-tone audiograms and auditory brain stem responses, and masked bone conduction thresholds from pure-tone audiograms. RESULTS: Thirty-six patients had homozygous STRC deletions. Three were compound heterozygotes. All patients had bilateral, symmetric SNHL. Baseline HL was mild in 39% of ears, moderate in 52%, and moderate-severe in 3%. Of the 31 patients for which sufficient data were available to evaluate progression, 18 (58%) had some degree of progressive HL. Among these 31 patients assessed for progression, the mean hearing threshold declined by 0.6 dB per year (95% confidence interval: 0.5, 0.8; P < .001). CONCLUSIONS: These biallelic STRC patients displayed HL ranging from mild to moderate-severe at baseline and progressing in 58%. The variability of the STRC phenotype and the possibility of audiologic progression should be considered in the clinical management of pediatric STRC-related SNHL. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E2897-E2903, 2021.

Gadolinium-based contrast agent for Magnetic Resonance Imaging as a predictor of postmeningitic hearing loss in children.

OBJECTIVE: To determine if Gadolinium-based enhanced Magnetic Resonance Imaging (GdMRI) can be used to predict sensorineural hearing loss (SNHL) in pediatric patients diagnosed with bacterial meningitis. STUDY: Design: Retrospective chart review. SETTING: Primary Children's Hospital, Salt Lake City, Utah. SUBJECTS: and Methods: We studied forty-two pediatric patients diagnosed with bacterial meningitis who underwent brain GdMRI during their index hospital admission and for whom ear specific audiometric data were available (August 2008-July 2018). A pediatric neuroradiologist, blinded to both disease and audiometric data, rated cochlear enhancement of each GdMRI (0-3; none to markedly enhanced). RESULTS: Ear specific MRI scores were statistically significantly related to ear specific hearing outcomes (p < 0.01). SNHL occurred in 19 out of 82 ears (12 out of 42 patients; 2 ears were excluded due to pre-existing SNHL in one ear and inability to read the GdMRI on the other ear). Ten of 19 ears (53%) that developed SNHL showed mild/moderate/marked enhancement (MRI score of 1, 2, or 3 respectively). Fifty-three of the 63 unaffected ears (84%) showed no enhancement (MRI score of 0). Ten of 13 (77%) ears that developed severe to profound SNHL showed mild/moderate/marked enhancement. GdMRI was 58% sensitive and 84% specific in predicting which ears would develop SNHL. GdMRI was 77% sensitive and 84% specific in identifying severe to profound SNHL. CONCLUSION: Our study demonstrates that GdMRI is a promising tool for predicting specifically severe-profound hearing loss in pediatric patients following bacterial meningitis infection.

Validation of a Parent Proxy Quality-of-Life Measure for Young Children With Hearing Loss.

OBJECTIVES: No hearing-related quality of life (QL) questionnaire currently exists for children < 7 years. This study aimed to develop and evaluate the construct validity and reliability of a new parent-proxy Preschool Hearing Environments and Reflection on Quality of Life (HEAR-QL) questionnaire. METHODS: Parents of children 2 to 6 years old with any hearing loss (HL) were recruited from multiple sites. To evaluate the new measure's construct validity, participants completed a 70-item preschool HEAR-QL and validated questionnaires measuring hearing and communication functioning (Parents' Evaluation of Aural/Oral Performance of Children), generic pediatric QL (Pediatric Quality of Life Inventory Parent Report, PedsQL), family functioning (PedsQL Family Impact Module), and parent well-being (Patient Reported Outcomes Measurement Information System Adult Global Report). Participants completed the preschool HEAR-QL 2 weeks later to measure test-retest reliability. Exploratory principal components analysis was used to reduce the number of items and determine the underlying HEAR-QL factor structure. Analysis of variance examined HEAR-QL differences by HL. RESULTS: Among 205 parents, 144 had children with bilateral HL, 50 had children with unilateral HL, 10 had children with normal hearing (NH), and one child's hearing status was unspecified. The 70-item questionnaire was reduced to 23 items with five underlying factors: Behavior and Attention, Hearing Environments, New Social Situations, Social Interactions, and Communication. Cronbach's alpha for each factor ranged from 0.80 to 0.91. Test-retest reliability was 0.93. Moderate-to-strong correlations (r > .300) were observed between each Preschool HEAR-QL factor and previously validated measures. Hearing Environments scores differed significantly between children with NH and any HL. CONCLUSION: Preschool HEAR-QL correlations with other measures supported its construct validity. Discriminant validity testing requires a larger sample of children with NH. LEVEL OF EVIDENCE: NA Laryngoscope, 131:663-670, 2021.

Drug delivery to the pediatric upper airway.

Pediatric upper airway disorders are frequently life-threatening and require precise assessment and intervention. Targeting these pathologies remains a challenge for clinicians due to the high complexity of pediatric upper airway anatomy and numerous potential etiologies; the most common treatments include systemic delivery of high dose steroids and antibiotics or complex and invasive surgeries. Furthermore, the majority of innovative airway management technologies are only designed and tested for adults, limiting their widespread implementation in the pediatric population. Here, we provide a comprehensive review of the most recent challenges of managing common pediatric upper airway disorders, describe the limitations of current clinical treatments, and elaborate on how to circumvent those limitations via local controlled drug delivery. Furthermore, we propose future advancements in the field of drug-eluting technologies to improve pediatric upper airway management outcomes.

ESRP1 Mutations Cause Hearing Loss due to Defects in Alternative Splicing that Disrupt Cochlear Development.

Alternative splicing contributes to gene expression dynamics in many tissues, yet its role in auditory development remains unclear. We performed whole-exome sequencing in individuals with sensorineural hearing loss (SNHL) and identified pathogenic mutations in Epithelial Splicing-Regulatory Protein 1 (ESRP1). Patient-derived induced pluripotent stem cells showed alternative splicing defects that were restored upon repair of an ESRP1 mutant allele. To determine how ESRP1 mutations cause hearing loss, we evaluated Esrp1-/- mouse embryos and uncovered alterations in cochlear morphogenesis, auditory hair cell differentiation, and cell fate specification. Transcriptome analysis revealed impaired expression and splicing of genes with essential roles in cochlea development and auditory function. Aberrant splicing of Fgfr2 blocked stria vascularis formation due to erroneous ligand usage, which was corrected by reducing Fgf9 gene dosage. These findings implicate mutations in ESRP1 as a cause of SNHL and demonstrate the complex interplay between alternative splicing, inner ear development, and auditory function.

Intracranial complications of sinusitis in children and adolescents and their outcomes.

OBJECTIVE: To gain insight into patterns of presentation, imaging, microbiological aspects, therapy, disease course, and outcome of intracranial complications of sinusitis (ICS), which are challenging conditions with the potential to cause significant morbidity and mortality. We reviewed our experience with ICS in children and adolescents. DESIGN: Consecutive case series with a mean follow-up of 12 months. SETTING: Tertiary pediatric referral center. PATIENTS: Consecutive sample of 25 children and adolescents treated for 35 intracranial complications (mean age, 13.2 years [range, 4-18 years]). INTERVENTIONS: Medical and surgical management. MAIN OUTCOME MEASURES: Survival and temporary and permanent neurologic sequelae. RESULTS: Most patients were adolescents (n = 19; 76%) and male (n = 19; 76%). Epidural abscess was most common (13 complications), followed by subdural empyema (n = 9), meningitis (n = 6), encephalitis (n = 2), intracerebral abscess (n = 2), and dural sinus thrombophlebitis (n = 2). Abscesses were primarily located in the frontal or frontoparietal regions. Magnetic resonance imaging was extensively used and was superior to contrast computed tomography in diagnosis. All patients received intravenous antibiotics, 21 underwent endoscopic sinus surgery, and 13 underwent neurosurgical drainage. Only 1 death occurred from sepsis secondary to meningitis (mortality, 4%). Overall, neurologic outcome was excellent. Although 10 patients (40%) had neurologic deficits, most resolved within 2 months. Only 2 patients had permanent neurologic sequelae. Among ICS, epidural abscess appeared to be a distinct clinical entity. Epidural abscesses typically presented without specific neurologic symptoms or signs, were more often associated with orbital complications, and had outcomes considerably better than the other ICS. CONCLUSION: Intracranial complications of sinusitis are challenging, but prognosis can be favorable in children and adolescents by using aggressive medical and surgical management.

Infectious complications and ventilation tubes in pediatric cochlear implant recipients.

OBJECTIVES/HYPOTHESIS: At many centers, ventilating tubes (VTs) are placed routinely in otitis-prone pediatric cochlear implant recipients. However, this practice is controversial, as many otologists believe VTs represent a possible route for contamination of the device. Toward better understanding of the safety of VTs, we reviewed our center's infectious complications and their relationship to the presence of tubes. STUDY DESIGN: Retrospective cohort study. METHODS: All patients undergoing cochlear implantation at our institution between 1990 and 2012 were reviewed for complications and their association with the presence of VTs. RESULTS: A total of 478 patients (557 ears) were reviewed, representing over 2,978 patient-years of follow-up. In 135 ears (24.2%), a VT was present at time of, or placed at some point after, implantation. The remainder either never had a VT or it had extruded prior to implantation. Overall, 63 complications occurred, of which 17 were infectious. The most common were cellulitis (four), device infection (five), and meningitis (four). Only one occurred while a tube was present, and was a device infection in an ear having a retained VT in place for almost 4 years. No difference was observed in overall rates of infectious complications between the group with VTs and those who never had VTs. CONCLUSIONS: This series, the largest to date, indicates that infectious complications after cochlear implantation are rarely associated with the presence of VTs, supporting the concept that, overall, VTs are safe in cochlear implant recipients. Close monitoring is essential, including prompt removal of tubes when they are no longer needed. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:1671-1676, 2016.

International Pediatric Otolaryngology Group (IPOG) consensus recommendations: Hearing loss in the pediatric patient.

OBJECTIVE: To provide recommendations for the workup of hearing loss in the pediatric patient. METHODS: Expert opinion by the members of the International Pediatric Otolaryngology Group. RESULTS: Consensus recommendations include initial screening and diagnosis as well as the workup of sensorineural, conductive and mixed hearing loss in children. The consensus statement discusses the role of genetic testing and imaging and provides algorithms to guide the workup of children with hearing loss. CONCLUSION: The workup of children with hearing loss can be guided by the recommendations provided herein.

Chronic Pseudomonas infections of cochlear implants.

OBJECTIVE: To discuss chronic, refractory Pseudomonas infections of cochlear implants and their management. DESIGN: Retrospective case series. SETTING: Two university-based cochlear implant programs. PATIENTS: Twenty-eight-year-old (Case 1) and 4-year-old (Case 2), different devices. INTERVENTIONS: Medical and surgical management. MAIN OUTCOME MEASURES: Clinical course. RESULTS: Both patients had delayed presentations, 4 months and 3 years postimplantation, respectively, with fluctuating scalp edema and pain resistant to multiple courses of oral antibiotics. Infections began as localized granulation and progressed to complete encasement of both devices with rubbery, poorly vascularized tissue. In each case, two different strains of multiresistant Pseudomonas aeruginosa were cultured. Infections progressed despite local debridement and targeted antipseudomonal antibiotic coverage, and sensitive organisms continued to appear in cultures of refractory granulation tissue. Both patients underwent partial explantation, with the electrode array left in the cochlea, then received 2 to 3 more months of further medical therapy and observation and then were reimplanted successfully with new devices. Both have shown excellent performance and no sign of recurrent infection. CONCLUSIONS: Infections of cochlear implants are uncommon, and cases of successful conservative management without device explantation have been reported. However, our experience and the implanted device literature suggest that chronic Pseudomonas infections may represent a distinct clinical entity, likely to fail protracted therapy and ultimately require device removal. Fortunately, successful reimplantation is possible.

Unilateral cochlear nerve deficiency in children.

OBJECTIVE: Cochlear nerve deficiency (CND) is increasingly diagnosed in children with sensorineural hearing loss (SNHL). We sought to determine the prevalence of CND, its imaging characteristics, and correlations with audiologic phenotype in children with unilateral SNHL. DESIGN: Case series with chart review. SETTING: Tertiary pediatric hospital. SUBJECTS/METHODS: In 128 consecutive children with unilateral SNHL who underwent high-resolution magnetic resonance imaging, the diameters, area, and signal intensity of the cochlear nerve (CN) were measured and normalized to the ipsilateral facial nerve. Presence of CND was determined by comparison to normative data. Relationships among hearing loss severity, progression, and nerve size were investigated. RESULTS: Cochlear nerve deficiency was present in 26% of children with unilateral SNHL. Its prevalence was higher (48%) in severe to profound SNHL, especially when in infants (100%). Width of the bony cochlear nerve canal (BCNC) correlated strongly with relative CN diameter, density, and area (R = 0.5); furthermore, a narrow BCNC (<1.7 mm) strongly predicted CND. Severity of hearing loss modestly correlated with nerve size, although significant variability was observed. Progression never occurred unless there were other inner ear malformations, whereas in the non-CND group, it occurred in 22%. Ophthalmologic abnormalities were very common (67%) in CND children, particularly oculomotor disturbances. CONCLUSION: Cochlear nerve deficiency is a common cause of unilateral SNHL, particularly in congenital unilateral deafness. Width of the BCNC effectively predicts CND, a finding useful when only computed tomography imaging is available. In an ear with CND, hearing can be expected to remain stable over time. Diagnosis should prompt evaluation by an ophthalmologist.