Concomitant imaging and genetic findings in children with unilateral sensorineural hearing loss

A Prospective Study of Genetic Variants in Infants with Congenital Unilateral Sensorineural Hearing Loss

Children with unilateral sensorineural hearing loss (uSNHL) have a high risk of speech-language delays and academic difficulties. Still, challenges remain in the diagnosis of uSNHL. With a prospective cross-sectional design, 20 infants were consecutively recruited from a universal newborn hearing screening program and invited to genetic testing. Eighteen of the subjects agreed to genetic testing, 15 subjects with OtoSCOPE^® v.9 screening 224 genes, and four subjects underwent targeted testing, screening for chromosomal abnormalities or 105-137 gene mutations. The genetic results were described together with the 20 infants' previously published auditory profiles and imaging results. Genetic causes for the uSNHL were found in 28% of subjects (5/18) including CHARGE syndrome (CHD7), autosomal recessive non-syndromic hearing loss (GJB2), Townes-Brocks syndrome (SALL1), Pendred Syndrome (SLC26A4) and Chromosome 8P inverted duplication and deletion syndrome. In subjects with comorbidities (malformation of fingers, anus, brain, and heart), 100% were diagnosed with a genetic cause for uSNHL (3/3 subjects), while 13% (2/15 subjects) were diagnosed without comorbidities observed at birth (p = 0.002). Genetic testing for congenital uSNHL is currently efficient for alleged syndromes, whereas genetic variants for non-syndromic congenital uSNHL need further research.

A Prospective Study of Etiology and Auditory Profiles in Infants with Congenital Unilateral Sensorineural Hearing Loss

Congenital unilateral sensorineural hearing loss (uSNHL) is associated with speech-language delays and academic difficulties. Yet, controversy exists in the choice of diagnosis and intervention methods. A cross-sectional prospective design was used to study hearing loss cause in twenty infants with congenital uSNHL consecutively recruited from a universal neonatal hearing-screening program. All normal-hearing ears showed ≤20 dB nHL auditory brainstem response (ABR) thresholds (ABRthrs). The impaired ear median ABRthr was 55 dB nHL, where 40% had no recordable ABRthr. None of the subjects tested positive for congenital cytomegalovirus (CMV) infection. Fourteen subjects agreed to participate in magnetic resonance imaging (MRI). Malformations were common for all degrees of uSNHL and found in 64% of all scans. Half of the MRIs demonstrated cochlear nerve aplasia or severe hypoplasia and 29% showed inner ear malformations. Impaired ear and normal-hearing ear ABR input/output functions on a group level for subjects with ABRthrs < 90 dB nHL were parallel shifted. A significant difference in interaural acoustic reflex thresholds (ARTs) existed. In congenital uSNHL, MRI is powerful in finding a possible hearing loss cause, while congenital CMV infection may be relatively uncommon. ABRs and ARTs indicated an absence of loudness recruitment, with implications for further research on hearing devices.

Correlation of cochlear aperture stenosis with cochlear nerve deficiency in congenital unilateral hearing loss and prognostic relevance for cochlear implantation

The use of neonatal hearing screening has enabled the identification of congenital unilateral sensorineural hearing loss (USNHL) immediately after birth, and today there are several intervention options available to minimize potential adverse effects of this disease, including cochlear implantation. This study aims to analyze the characteristics of the inner ear of a homogeneous group of congenital non-syndromic USNHL to highlight the features of the inner ear, which can help in clinical, surgical, and rehabilitative decision-making. A retrospective chart review was carried out at a tertiary referral center. Systematic diagnostic work-up and rigorous inclusion-exclusion criteria were applied to 126 children with unilateral hearing impairment, leading to a selection of 39 strictly congenital and non-syndromic USNHL cases, undergoing computed tomography (CT) and magnetic resonance (MR) imaging studies. The frequency and type of malformations of the inner ear in USNHL and unaffected contralateral ears were assessed, with an in-depth analysis of the deficiency of the cochlear nerve (CND), the internal auditory canal (IAC) and the cochlear aperture (CA). Inner ear anomalies were found in 18 out of 39 (46%) of the USNHL patients. In 1 subject, the anomalies were bilateral, and the CND resulted in the predominant identified defect (78% of our abnormal case series), frequently associated with CA stenosis. Only 3 out of 14 children with CND presented stenosis of the IAC. CND and CA stenosis (and to a much lesser extent IAC stenosis) are a frequent association within congenital and non-syndromic USNHL that could represent a distinct pathological entity affecting otherwise healthy infants. In the context of a diagnostic work-up, the evaluation with CT and MRI measurements should take place in a shared decision-making setting with thorough counseling. Both imaging techniques have proven useful in differentiating the cases that will most likely benefit from the cochlear implant, from those with potentially poor implant performance.

[Common clinical causes and audiological manifestations of unilateral hearing loss in children]

Objective:To analyze the common clinical causes and audiological manifestations of unilateral hearing loss in children, and to provide a basis for early prevention and intervention. Method:A retrospective analysis of 20 cases of children diagnosed with unilateral hearing loss was conducted. The medical history was collected, followed by audiological and imaging examinations. Result:The audiological performance of 20 children with unilateral hearing loss: 1 case of conductive deafness, whose hearing curve was flat and showed moderate hearing loss. There were 19 cases of sensorineural deafness, of which 1 case was moderate deafness, 16 cases were severe deafness, and 2 cases were extremely severe deafness. The imaging results showed that there were 1 case with transverse fracture of the temporal bone, 1 case with congenital cholesteatoma, 9 cases with dysplasia of the cochlear nerve, and 4 cases with malformation of the inner ear. The history of the two children was collected and there were clear congenital cytomegalovirus infection and mumps virus infection. The causes of the remaining 3 cases were unknown. Conclusion:Unilateral hearing loss in children is a common clinical diseasewith complex and diverse causes. Carefully analysis should be made to find out the causes and symptomatic treatment to provide a basis for early prevention and intervention of children's hearing.

Assessment of the Clinical Benefit of Imaging in Children With Unilateral Sensorineural Hearing Loss: A Systematic Review and Meta-analysis

Importance

Imaging used to determine the cause of unilateral sensorineural hearing loss (USNHL) in children is often justified by the high likelihood of detecting abnormalities, which implies that these abnormalities are associated with hearing loss and that imaging has a positive contribution to patient outcome or well-being by providing information on the prognosis, hereditary factors, or cause of hearing loss.

Objectives

To evaluate the diagnostic yield of computed tomography (CT) and magnetic resonance imaging (MRI) in children with isolated unexplained USNHL and investigate the clinical relevance of these findings.

Evidence Review

Cochrane Library, Embase, PubMed, and Web of Science databases were searched for articles published from 1978 to 2017 on studies of children with USNHL who underwent CT and/or MRI of the temporal bone. Two authors (F.G.R. and E.N.B.P.) independently extracted information on population characteristics, imaging modality, and the prevalence of abnormalities and assessed the studies for risk of bias. Eligibility criteria included studies with 20 or more patients with USNHL who had CT and/or MRI scans, a population younger than 18 years, and those published in English.

Main Outcomes and Measures

The pooled prevalence with 95% CI of inner ear abnormalities grouped according to finding and imaging modality.

Findings

Of 1562 studies, 18 were included with a total of 1504 participants included in the analysis. Fifteen studies were consecutive case studies and 3 were retrospective cohort studies. The pooled diagnostic yield for pathophysiologic relevant findings in patients with unexplained USNHL was 37% for CT (95% CI, 25%-48%) and 35% for MRI (95% CI, 22%-49%). Cochleovestibular abnormalities were found with a pooled frequency of 19% for CT (95% CI, 14%-25%) and 16% for MRI (95% CI, 7%-25%). Cochlear nerve deficiency and associated cochlear aperture stenosis had a pooled frequency of 16% for MRI (95% CI, 3%-29%) and 44% for CT (95% CI, 36%-53%), respectively. Enlarged vestibular aqueduct (EVA) was detected with a pooled frequency of 7% for CT and 12% for MRI in children with USNHL.

Conclusions and Relevance

Imaging provided insight into the cause of hearing loss in a pooled frequency of about 35% to 37% in children with isolated unexplained USNHL. However, none of these findings had therapeutic consequences, and imaging provided information on prognosis and hereditary factors only in a small proportion of children, namely those with EVA. Thus, there is currently no convincing evidence supporting a strong recommendation for imaging in children who present with USNHL. The advantages of imaging should be carefully balanced against the drawbacks during shared decision making.

Early diagnosis and treatment of unilateral or asymmetrical hearing loss in children: CODEPEH recommendations

The aim of this document is to improve the management and the treatment of unilateral or asymmetrical hearing loss in children. One in one thousand newborn infants has unilateral hearing loss and this prevalence increases with age, due to cases of acquired and delayed-onset hearing loss. Although the impact on the development and learning processes of children of these kinds of hearing loss have usually been minimized, if they are not treated they will impact on language and speech development, as well as overall development, affecting the quality of life of the child and his/her family. The outcomes of the review are expressed as recommendations aimed at clinical diagnosis and therapeutic improvement for unilateral or asymmetrical hearing loss.