Diagnostic yield of computed tomography scan for pediatric hearing loss: a systematic review

Brazilian Society of Otology task force - cochlear implant ‒ recommendations based on strength of evidence

OBJECTIVE

To make evidence-based recommendations for the indications and complications of Cochlear Implant (CI) surgery in adults and children.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on cochlear implantation were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: (1) Evaluation of candidate patients and indications for CI surgery; (2) CI surgery - techniques and complications.

CONCLUSIONS

CI is a safe device for auditory rehabilitation of patients with severe-to-profound hearing loss. In recent years, indications for unilateral hearing loss and vestibular schwannoma have been expanded, with encouraging results. However, for a successful surgery, commitment of family members and patients in the hearing rehabilitation process is essential.

Utilization of computed tomography in pediatric temporal fractures: A dose reduction approach

OBJECTIVES

METHODS: Retrospective chart review was performed of pediatric patients who underwent CT brain as part of a trauma pan-scan and dedicated temporal bone CT in the setting of head trauma. The original CT images were re-reviewed by two board certified Neuroradiologists in a blinded manner to determine the presence or absence of temporal bone fracture and if present, fracture line involvement of the 5 critical temporal bone anatomic structures. The dose length product (DLP), a measure of approximate total radiation dose delivered during CT scan (mGy-cm), was noted from the data available.

RESULTS

There were 24 temporal bone fractures in a total of 29 patients (4 with bilateral fractures). There were 21 of 24 fractures that were correctly identified on trauma pan-scan CT with dedicated temporal bone CT considered as the diagnostic gold standard. There was a combined sensitivity and specificity of 91 % and 100 % respectively. The sensitivity and specificity in identifying involvement of critical structures were as follows: carotid canal (100 % and 100 %); ossicular chain (75 % and 100 %); tegmen tympani (60 % and 97.9 %); facial nerve canal (25 % and 100 %); otic capsule (N/A and 98.5 %). The median DLP for trauma pan-scan CT and temporal bone CT were 627 mGy-cm and 267 mGy-cm respectively.

CONCLUSION

Dedicated TBCT is not required to accurately diagnose and characterize temporal bone fractures seen on trauma pan-scan CT. The radiation exposure of concurrent or subsequent dedicated temporal bone imaging is equal to approximately one half of the original trauma pan-scan CT.

Task force Guideline of Brazilian Society of Otology ‒ hearing loss in children - Part I ‒ Evaluation

OBJECTIVES

To provide an overview of the main evidence-based recommendations for the diagnosis of hearing loss in children and adolescents aged 0 to 18 years.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on childhood hearing loss were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The evaluation and diagnosis of hearing loss: universal newborn hearing screening, laboratory testing, congenital infections (especially cytomegalovirus), genetic testing and main syndromes, radiologic imaging studies, vestibular assessment of children with hearing loss, auditory neuropathy spectrum disorder, autism spectrum disorder, and noise-induced hearing loss.

CONCLUSIONS

Every child with suspected hearing loss has the right to diagnosis and appropriate treatment if necessary. This task force considers 5 essential rights: (1) Otolaryngologist consultation; (2) Speech assessment and therapy; (3) Diagnostic tests; (4) Treatment; (5) Ophthalmologist consultation.

Functional Brain Connections Identify Sensorineural Hearing Loss and Predict the Outcome of Cochlear Implantation

Identification of congenital sensorineural hearing loss (SNHL) and early intervention, especially by cochlear implantation (CI), are crucial for restoring hearing in patients. However, high accuracy diagnostics of SNHL and prognostic prediction of CI are lacking to date. To diagnose SNHL and predict the outcome of CI, we propose a method combining functional connections (FCs) measured by functional magnetic resonance imaging (fMRI) and machine learning. A total of 68 children with SNHL and 34 healthy controls (HC) of matched age and gender were recruited to construct classification models for SNHL and HC. A total of 52 children with SNHL that underwent CI were selected to establish a predictive model of the outcome measured by the category of auditory performance (CAP), and their resting-state fMRI images were acquired. After the dimensional reduction of FCs by kernel principal component analysis, three machine learning methods including the support vector machine, logistic regression, and k-nearest neighbor and their voting were used as the classifiers. A multiple logistic regression method was performed to predict the CAP of CI. The classification model of voting achieves an area under the curve of 0.84, which is higher than that of three single classifiers. The multiple logistic regression model predicts CAP after CI in SNHL with an average accuracy of 82.7%. These models may improve the identification of SNHL through fMRI images and prognosis prediction of CI in SNHL.

Clinical and genetic analysis of children with hearing loss and bilateral enlarged vestibular aqueducts

OBJECTIVES

To evaluate the clinical and genetic features of children with hearing loss associated with one of the most common malformations of the inner ear: bilateral enlargement of vestibular aqueducts (EVA).

METHODS

Clinical and genetic features were investigated in 28 children with hearing loss diagnosed with bilateral EVA by computed tomography from January 2008 to September 2019.

RESULTS

Fourteen subjects had undergone newborn hearing screening (NHS). Nine subjects (64.3%) were referred in both ears, 4 subjects (28.6%) were referred in one ear, and one subject (7.1%) passed in both ears. Nineteen of 26 subjects (73.1%) who were followed for more than 3 years had hearing fluctuations, while 17 (65.4%) had hearing loss progression. Eleven of 28 subjects (39.2%) had vertigo attacks. Pathogenic variants were identified in two alleles of the SLC26A4 gene in 24 of 27 subjects (88.9%) by sequencing of all exons and flanking introns, leading to genetic diagnosis of Pendred syndrome/DFNB4. Our results indicate that genetic screening for specific SLC26A4 variants using a commercial clinical laboratory test in Japan would have achieved genetic diagnoses in 13 of the 27 subjects (54.2%). Although there was no statistically significance in the frequency of hearing fluctuation or progression depending on the presence or absence of the gene variant, mean hearing level was severe in subjects with two pathogenic variants in SLC26A4 gene. The most common variant detected in our subjects was p.His723Arg (13 alleles, 27.1%), followed by c. 919-2A > G (four alleles, 8.3%). Two novel variants were detected in this study: c.1544+1G > T and c.1614+5G > A.

CONCLUSIONS

Our data suggest that some subjects may present with bilateral EVA that cannot be detected by NHS. We estimated that genetic diagnosis for SLC264 gene would not have been made in almost half subjects with the commercial genetic screening approach used in the present study in Japan. Although there were some limitations in this study, the subjects with pathogenic variants in two alleles of the SLC26A4 gene could have more severe hearing loss.

Comprehensive medical evaluation of pediatric bilateral sensorineural hearing loss

Children with bilateral sensorineural hearing loss (SNHL) should undergo a comprehensive medical evaluation to determine the underlying etiology and help guide treatment and counseling. In this article, we review the indications and rationale for medical evaluation of pediatric bilateral SNHL, including history and physical examination, imaging, genetic testing, specialist referrals, cytomegalovirus (CMV) testing, and other laboratory tests. Workup begins with a history and physical examination, which can provide clues to the etiology of SNHL, particularly with syndromic causes. If SNHL is diagnosed within the first 3 weeks of life, CMV testing should be performed to identify patients that may benefit from antiviral treatment. If SNHL is diagnosed after 3 weeks, testing can be done using dried blood spots samples, if testing capability is available. Genetic testing is oftentimes successful in identifying causes of hearing loss as a result of recent technological advances in testing and an ever-increasing number of identified genes and genetic mutations. Therefore, where available, genetic testing should be performed, ideally with next generation sequencing techniques. Ophthalmological evaluation must be done on all children with SNHL. Imaging (high-resolution computed tomography and/or magnetic resonance imaging) should be performed to assess for anatomic causes of hearing loss and to determine candidacy for cochlear implantation when indicated. Laboratory testing is indicated for certain etiologies, but should not be ordered indiscriminately since the yield overall is low.

Imaging in pediatric bilateral sensorineural hearing loss: Diagnostic yield with computed tomography versus magnetic resonance imaging

OBJECTIVES

To evaluate the findings and compare the diagnostic yield of computed tomography (CT) versus magnetic resonance imaging (MRI) in children with bilateral sensorineural hearing loss (BSNHL).

STUDY DESIGN

Multi-institutional retrospective review.

SETTING

Three tertiary referral centers.

METHODS

A multi-institutional retrospective chart review was performed in patients under the age of 18 years with BSNHL (diagnosis codes 389.00-389.22) who underwent both CT and MRI from 2010 to 2012. An abnormal imaging finding was defined as an abnormality of the cochleovestibular or central nervous system known to directly correlate with sensorineural hearing loss. Diagnostic yield of CT versus MRI was compared by McNemar's test.

RESULTS

Of 2081 charts reviewed, 313 patients met inclusion criteria. The diagnostic yield of CT and MRI were 25% and 18%, respectively. Approximately one-quarter of patients had an abnormal finding on CT or MRI. The concordance rate was 92%. CT was more likely to yield an abnormal finding versus MRI (p-value = 0.0001). The most common findings on CT were cochlear and semicircular canal abnormalities. On MRI, the most common findings were cochlear nerve aplasia/hypoplasia and semicircular canal abnormalities.

CONCLUSIONS

This study evaluates and directly compares the diagnostic yield of CT versus MRI for pediatric BSNHL. While both modalities have important and often complementary diagnostic utility, CT had superior diagnostic yield in identifying abnormalities associated with BSNHL.

Congenital Hearing Loss Is Associated With a High Incidence of Central Nervous System Abnormalities

OBJECTIVE(S)

To assess the incidence of central nervous system abnormalities in pediatric subjects with sensorineural hearing loss (SNHL).

METHODS

One hundred forty-three pediatric subjects evaluated for SNHL at a single academic center from 2007 to 2014 were included and divided into eight diagnosis groups based on etiology of SNHL. One hundred forty-three age- and gender-matched control subjects with no known brain-related pathology or history of hearing loss were included as healthy controls for comparison. Two neuroradiologists independently evaluated magnetic resonance imaging (MRI) and computed tomography (CT) scans for each subject. Comparison of abnormal cerebral development was performed using an ordinal logistic regression model. Concordance between CT and MRI of the temporal bone was assessed using the kappa statistic.

RESULTS

The etiologies of hearing loss in our cohort were 37.8% genetic, 12.6% infectious, 1.4% ototoxin-induced, and 48.3% idiopathic. Brain MRI revealed cerebral developmental abnormalities in defined regions in >30% of the SNHL cohort, significantly more than in normal-hearing pediatric controls. The Sylvian fissure, Virchow-Robin spaces, and lateral ventricles were most commonly affected. In the temporal bone, the percentage of subjects with concordant findings on CT and MRI was ≥92% across all anatomical structures.

CONCLUSION

MRI revealed a high incidence of intracranial abnormalities, suggestive of aberrant development of auditory and nonauditory neural structures associated with SNHL. CT and MRI share a high degree of concordance in detecting temporal bone anomalies. Inclusion of MRI as part of the workup of congenital SNHL may facilitate the detection of developmental anomalies of the brain associated with SNHL.

[Computer tomography demonstrations of single-sided deafness]

Objective:To investigate the distribution of common inner ear and internal auditory canal malformations in children with single-sided deafness（SSD） ,and to explore the imaging etiology of SSD by comparing the quantitative parameters of key bone structures between deaf and normal ears in children with congenital SSD. Method:Forty children with SSD diagnosed in the Second Hospital of Lanzhou University from September 2016 to March 2019 were collected. All of them underwent HRCT examinations of temporal bone . The area of bone island, the width of vestibular, the width of internal auditory canal, the height of cochlear and the width of cochlear basal axis were measured. Paired t test was used to compare the difference between the hearing abnormality and normal hearing in children with SSD. Result:The rate of inner ear deformity was 62.5% in SSD group,the most common deformity was cochlear nerve canal deformity, 20 cases （50.0%） of cochlear canal stenosis and 3 cases （7.5%） of cochlear canal atresia.The second most common deformity was internal auditory canal deformity, including 5 cases （12.5%） of internal auditory canal stenosis and 1 case （2.5%） of internal auditory canal atresia. Other malformations included 1 case（2.5%） of RO, 2 cases （5.0%） of incomplete partition （IP） type II and 1 case （2.5%） of enlargement of vestibular aqueduct （EVA）. There are no significant difference in the measured results of the key structures of the inner ear between two groups except the width of cochlear nerve canal, internal auditory canal and the area of bone island. Conclusion:The main inner ear deformities in children with SSD are cochlear nerve canal stenosis and inner auditory canal stenosis. HRCT of temporal bone has high diagnostic value for inner ear deformities in children with SSD.

Medical Referral Patterns and Etiologies for Children With Mild-to-Severe Hearing Loss

OBJECTIVES

To (1) identify the etiologies and risk factors of the patient cohort and determine the degree to which they reflected the incidence for children with hearing loss and (2) quantify practice management patterns in three catchment areas of the United States with available centers of excellence in pediatric hearing loss.

DESIGN

Medical information for 307 children with bilateral, mild-to-severe hearing loss was examined retrospectively. Children were participants in the Outcomes of Children with Hearing Loss (OCHL) study, a 5-year longitudinal study that recruited subjects at three different sites. Children aged 6 months to 7 years at time of OCHL enrollment were participants in this study. Children with cochlear implants, children with severe or profound hearing loss, and children with significant cognitive or motor delays were excluded from the OCHL study and, by extension, from this analysis. Medical information was gathered using medical records and participant intake forms, the latter reflecting a caregiver's report. A comparison group included 134 children with normal hearing. A Chi-square test on two-way tables was used to assess for differences in referral patterns by site for the children who are hard of hearing (CHH). Linear regression was performed on gestational age and birth weight as continuous variables. Risk factors were assessed using t tests. The alpha value was set at p < 0.05.

RESULTS

Neonatal intensive care unit stay, mechanical ventilation, oxygen requirement, aminoglycoside exposure, and family history were correlated with hearing loss. For this study cohort, congenital cytomegalovirus, strep positivity, bacterial meningitis, extracorporeal membrane oxygenation, and loop diuretic exposure were not associated with hearing loss. Less than 50% of children underwent imaging, although 34.2% of those scanned had abnormalities identified. No single imaging modality was preferred. Differences in referral rates were apparent for neurology, radiology, genetics, and ophthalmology.

CONCLUSIONS

The OCHL cohort reflects known etiologies of CHH. Despite available guidelines, centers of excellence, and high-yield rates for imaging, the medical workup for children with hearing loss remains inconsistently implemented and widely variable. There remains limited awareness as to what constitutes appropriate medical assessment for CHH.

Evaluating diagnostic yield of computed tomography (CT) and magnetic resonance imaging (MRI) in pediatric unilateral sensorineural hearing loss

INTRODUCTION

Options for imaging for evaluation of pediatric patients with unilateral sensorineural hearing loss (USNHL) include computed tomography (CT) and magnetic resonance imaging (MRI). Although both CT and MR imaging provide valuable information in the evaluation of pediatric patients with USNHL, debate remains regarding which imaging modality is most ideal and should be the preferred study for these children. The objective of this study is to evaluate and compare the diagnostic yield of CT versus MRI in children with USNHL.

METHODS

A multi-institutional retrospective chart review was conducted. Pediatric patients with hearing loss (diagnosis codes 389.00-389.22) seen between 2010 and 2012 at three tertiary care centers were identified. Only patients with USNHL and imaging studies were reviewed and results of CT and MRI for each patient were examined and compared. Cochleovestibular or central nervous system findings known to directly correlate to SNHL were noted as positive findings on imaging. McNemar's test was used to compare patients with positive CT and MRI results.

RESULTS

A total of 219 patients between the ages of 0-18 years with USNHL who underwent CT and/or MRI were identified. Imaging abnormalities were found in 41/96 patients who underwent MRI with overall diagnostic yield of 42.7% and 69 of 188 patients who underwent CT with overall diagnostic yield of 36.7%. For patients who underwent both imaging modalities (n = 65), there was no statistically significant difference in positive findings detected by CT vs MRI (p > 0.05).

CONCLUSIONS

Both CT and MR imaging have similar overall diagnostic yield when used to evaluate children with USNHL. Parents and patients should be counseled regarding cost, test duration, radiation exposure, need for sedation, and diagnostic accuracy associated with each imaging modality and these factors should be considered to select the appropriate diagnostic study.

Comprehensive Genetic Testing for Deafness from Fresh and Archived Dried Blood Spots

Comprehensive genetic testing has become integral in the evaluation of children with deafness, but the amount of blood required to obtain DNA can be prohibitive in newborns. Dried blood spots (DBSs) are routinely collected and would provide an alternative source of DNA. Our objective was to evaluate the use of DBSs for comprehensive genetic testing for deafness. DNA derived from fresh and archived DBS samples was compared with DNA from whole blood. We performed next-generation sequencing of all known deafness genes in 4 DBS samples: 2 positive controls, an unknown sample, and a negative control. The DBS-derived DNA was of sufficient quantity and quality for clinical testing. In the 2 positive control samples, pathogenic variants were identified; in the negative control, no pathogenic variants were found; and in the unknown sample, homozygous deletion of the OTOA gene was identified as the cause of deafness. This pilot study shows that comprehensive genetic testing for deafness is feasible with fresh and/or archived DBSs.

Diagnosis and Treatment of Congenital Sensorineural Hearing Loss

Purpose of Review

The aim of this report is to review current literature regarding the work-up and management of congenital sensorineural hearing loss.

Recent Findings

Diagnostic evaluation of a newborn with sensorineural hearing loss begins with a complete audiologic evaluation and comprehensive history and physical exam. This review presents a diagnostic algorithm for the work-up of congenital hearing loss, focusing on the three following modalities: cytomegalovirus testing, genetic evaluation, and imaging.

Summary

Newborn hearing loss is a common problem and may be attributed to genetic and non-genetic factors. Complete diagnostic evaluation and treatment are essential for preventing delays in language development. Treatment consists of early intervention services and consideration of hearing aid amplification and cochlear implantation.

Does an Otolaryngology-Specific Database Have Added Value? A Comparative Feasibility Analysis

OBJECTIVES

There are multiple nationally representative databases that support epidemiologic and outcomes research, and it is unknown whether an otolaryngology-specific resource would prove indispensable or superfluous. Therefore, our objective was to determine the feasibility of analyses in the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) databases as compared with the otolaryngology-specific Creating Healthcare Excellence through Education and Research (CHEER) database.

STUDY DESIGN

Parallel analyses in 2 data sets.

SETTING

Ambulatory visits in the United States.

SUBJECTS AND METHODS

To test a fixed hypothesis that could be directly compared between data sets, we focused on a condition with expected prevalence high enough to substantiate availability in both. This query also encompassed a broad span of diagnoses to sample the breadth of available information. Specifically, we compared an assessment of suspected risk factors for sensorineural hearing loss in subjects 0 to 21 years of age, according to a predetermined protocol. We also assessed the feasibility of 6 additional diagnostic queries among all age groups.

RESULTS

In the NAMCS/NHAMCS data set, the number of measured observations was not sufficient to support reliable numeric conclusions (percentage standard error among risk factors: 38.6-92.1). Analysis of the CHEER database demonstrated that age, sex, meningitis, and cytomegalovirus were statistically significant factors associated with pediatric sensorineural hearing loss (P < .01). Among the 6 additional diagnostic queries assessed, NAMCS/NHAMCS usage was also infeasible; the CHEER database contained 1585 to 212,521 more observations per annum.

CONCLUSION

An otolaryngology-specific database has added utility when compared with already available national ambulatory databases.

Charges associated with imaging techniques in evaluation of pediatric hearing loss

OBJECTIVE

The best imaging study for evaluation of pediatric hearing loss is debated and it is well known magnetic resonance imaging is more costly than computed tomography. The objective of this study is to evaluate charges of computed tomography temporal bone (CTTB) versus magnetic resonance imaging brain, internal auditory canal/cerebellopontine angle (MRI IAC/CPA), with and without sedation in the pediatric population in order to assess to what extent the charges for the procedure are increased. In addition, differences in need for sedation and duration of sedation will be evaluated.

METHODS

All patients, 0-18 years that underwent CTTB or MRI IAC/CPA, between January 2013 through December 2014 within department of otolaryngology.

RESULTS

120 CTTBs (118 non-sedated and 2 sedated) and 51 MRI IAC/CPAs (32 non-sedated and 19 sedated) were performed. Average charge for non-sedated CTTB was $1856. CTTB scan under sedation incurred total additional charges of $2385. Average charges for non-sedated MRI IAC/CPA was $3770. Technical charges for sedated MRI IAC/CPA was $151 lower ($2858) but had additional sedation charges of $2256, a recovery room charge of $250, and additional professional fees of $1496 for total charges of $7621. 37% of MRI IAC/CPAs needed sedation to be completed in comparison to 1.6% of CTTB.

CONCLUSION

MRI IAC/CPAs are, on average, twice as costly as CTTBs. Almost 40% of patients need sedation to complete MRI IAC/CPA. These considerations may factor into decision making when choosing imaging modality in evaluation of pediatric hearing loss.

Diagnosis and Management of Congenital Sensorineural Hearing Loss

Hearing loss is the most common sensory disorder in the USA. The diagnosis of congenital hearing loss starts with newborn hearing screening, which is best performed with auditory brainstem evoked responses in order to avoid the risk of missing auditory neuropathy spectrum disorder. A careful history and physical exam can occasionally help reveal the etiology for congenital hearing loss. Imaging studies, either CT temporal bones or MRI of the internal auditory canals without gadolinium, and genetic testing, in particular for connexin 26, connexin 30, and Pendred syndrome, are the most useful diagnostic tests. Management of congenital hearing loss involves early fitting of amplification. Early cochlear implantation, preferably before 2 years of age, should be strongly considered for children with bilateral severe hearing loss.

Life-threatening unilateral hearing impairments. Review of the literature on the association between inner ear malformations and meningitis

BACKGROUND

Bacterial meningitis is a life threatening disease that can be triggered by a CSF leak through an inner ear malformation. Early identification of the specific type of cochleovestibular dysplasia and the associated risk of meningitis is of vital importance.

OBJECTIVES

The objective of this review is to collect and discuss available data on the association between inner ear malformations and meningitis in children.

METHODS

Electronic databases were crosschecked for obtaining relevant papers published in the last 20 years, and further cases were identified by hand searching through the references. Demographic data were extracted from full texts, together with information on the severity of hearing impairment, the type of inner ear anomaly, the site of cerebrospinal fluid leak, the number of recurrent meningitis episodes.

RESULTS

Sixty-seven cases of meningitis related to inner ear malformation have been identified among 45 papers. Mean age at presentation is 3.60±3.00 (range 0.1-14) years. Average diagnostic delay from the first episode of meningitis is 3.44±3.41 (range 0.00-10.00) years. The number of meningitis episodes that occurred before the correct diagnosis and definitive surgical treatment is 3.27±1.81 (range 1.00-10.00). Unilateral hearing impairment affects 70% of patients. Six patients had normal hearing at presentation. Two children are dead from inner-ear-malformation-related meningitis among reviewed reports.

CONCLUSION

A high number of paediatric patients carrying inner ear malformations, especially when associated with unilateral hearing impairment, could be at risk to develop recurrent bacterial meningitis. Universal newborn hearing screening programs should prompt a diagnostic work-up even in the case of unilateral hearing impairment, in order to prevent inner ear malformation-related meningitis.

Sensorineural Hearing Loss: A Changing Paradigm for Its Evaluation

OBJECTIVE

To determine how practicing clinicians evaluate patients with sensorineural hearing loss (SNHL) and to analyze the cost-effectiveness of current algorithms in the evaluation of these patients.

STUDY DESIGN/SETTING

An interactive online survey allowing respondents to order diagnostic testing in the evaluation of 4 simulated patients with SNHL across 2 testing encounters per patient.

SUBJECTS AND METHODS

The survey was distributed to clinician members of the American Society of Pediatric Otolaryngology and the American Society of Human Genetics between May and August 2014. Statistical tests included chi-square and nonparametric testing with Mann-Whitney U test.

RESULTS

Otolaryngologists were significantly more likely than other clinicians to order repeat audiometric testing and significantly less likely to order genetic testing. Respondents who completed training more recently were significantly more likely to order magnetic resonance imaging and electrocardiogram. On average, respondents spent $4756 in the evaluation of a single patient, with otolaryngologists spending significantly more than other clinicians. Computed tomography of the temporal bone (40%), ophthalmology consultation (39%), and genetics consultation (37%) were ordered most frequently in the first encounter. Comprehensive genetic testing was ordered least frequently on the first encounter (20%) but was the most frequently ordered test on the second encounter (30%).

CONCLUSION

Recent guidelines advocate comprehensive genetic testing in the evaluation of patients with SNHL, as early genetic testing can prevent uninformative additional tests that otherwise increase health care expenditures. Results from this survey indicate that comprehensive genetic testing is now frequently but not uniformly included in evaluation of patients with SNHL.

Progressive Hearing Loss and Head Trauma in Enlarged Vestibular Aqueduct

Objective

Enlarged vestibular aqueduct is the most common radiographically identified cause of congenital sensorineural hearing loss and is frequently progressive. Imaging is often ordered during the workup of children with congenital sensorineural hearing loss in part to identify enlarged vestibular aqueduct given concern for progression with head trauma. However, this association has not been systematically evaluated. We aimed to determine the rate of progression and association with head trauma in individuals with enlarged vestibular aqueduct.

Data Sources

Systematic review of primary studies identified through PubMed, Embase, Cochrane, and Web of Science.

Review Methods

Meta-analysis was performed on patient-level data describing enlarged vestibular aqueduct, progressive sensorineural hearing loss, and head trauma extracted from articles identified on systematic review according to PRISMA guidelines.

Results

Twenty-three studies (1115 ears with enlarged vestibular aqueduct) met inclusion criteria. Progressive sensorineural hearing loss was found in 39.6% of ears, with trauma-associated progression in 12%. Limited case-control data show no difference in the incidence of progression between patients with and without head trauma.

Conclusions

Long-term progressive sensorineural hearing loss is common in enlarged vestibular aqueduct, but its association with head trauma is not strongly supported.

Diagnostic yield of MRI for pediatric hearing loss: a systematic review

OBJECTIVE

To perform a systematic review to analyze the diagnostic yield of magnetic resonance imaging (MRI) for pediatric hearing loss, including comparison to computed tomography (CT) and subgroup evaluation according to impairment severity and specific diagnostic findings (cochlear anomalies, enlarged vestibular aqueduct, cochlear nerve abnormalities, and brain findings).

DATA SOURCES

Pubmed, EMBASE, and the Cochrane library were assessed from their inception through December 2013. Manual searches were also performed, and topic experts were contacted.

REVIEW METHODS

Data from studies describing the use of MRI with or without comparison to CT in the diagnostic evaluation of pediatric patients with hearing loss were evaluated, according to a priori inclusion/exclusion criteria. Two independent evaluators corroborated the extracted data. Heterogeneity was evaluated according to the I(2) statistic.

RESULTS

There were 29 studies that evaluated 2434 patients with MRIs and 1451 patients with CTs that met inclusion/exclusion criteria. There was a wide range of diagnostic yield from MRI. Heterogeneity among studies was substantial but improved with subgroup analysis. Meta-analysis of yield differences demonstrated that CT had a greater yield than MRI for enlarged vestibular aqueduct (yield difference 16.7% [95% CI, 9.1%-24.4%]) and a borderline advantage for cochlear anomalies (4.7% [95% CI, 0.1%-9.5%]). Studies were more likely to report brain findings with MRI.

CONCLUSIONS

These data may be utilized in concert with that from studies of risks of MRI and risk/yield of CT to inform the choice of diagnostic testing.