The spectrum of cochlear malformations in CHARGE syndrome and insights into the role of the CHD7 gene during embryogenesis of the inner ear.

PURPOSE: We reviewed the genotypes and the imaging appearances of cochleae in CHARGE patients from two large tertiary centres and analysed the observed cochlear anomalies, providing detailed anatomical description and a grading system. The goal was to gain insight into the spectrum of cochlear anomalies in CHARGE syndrome, and thus, in the role of the CHD7 gene in otic vesicle development. METHODS: We retrospectively reviewed CT and/or MR imaging of CHARGE patients referred to our institutions between 2005 and 2022. Cochlear morphology was analysed and, when abnormal, divided into 3 groups in order of progressive severity. Other radiological findings in the temporal bone were also recorded. Comparison with the existing classification system of cochlear malformation was also attempted. RESULTS: Cochlear morphology in our CHARGE cohort ranged from normal to extreme hypoplasia. The most common phenotype was cochlear hypoplasia in which the basal turn was relatively preserved, and the upper turns were underdeveloped. All patients in the cohort had absent or markedly hypoplastic semicircular canals and small, misshapen vestibules. Aside from a stenotic cochlear aperture (fossette) being associated with a hypoplastic or absent cochlear nerve, there was no consistent relationship between cochlear nerve status (normal, hypoplasia, or aplasia) and cochlear morphology. CONCLUSION: Cochlear morphology in CHARGE syndrome is variable. Whenever the cochlea was abnormal, it was almost invariably hypoplastic. This may shed light on the role of CHD7 in cochlear development. Accurate morphological description of the cochlea contributes to proper clinical diagnosis and is important for planning surgical treatment options.

Sodium Thiosulfate for Protection from Cisplatin-Induced Hearing Loss.

BACKGROUND: Cisplatin chemotherapy and surgery are effective treatments for children with standard-risk hepatoblastoma but may cause considerable and irreversible hearing loss. This trial compared cisplatin with cisplatin plus delayed administration of sodium thiosulfate, aiming to reduce the incidence and severity of cisplatin-related ototoxic effects without jeopardizing overall and event-free survival. METHODS: We randomly assigned children older than 1 month and younger than 18 years of age who had standard-risk hepatoblastoma (≤3 involved liver sectors, no metastatic disease, and an alpha-fetoprotein level of >100 ng per milliliter) to receive cisplatin alone (at a dose of 80 mg per square meter of body-surface area, administered over a period of 6 hours) or cisplatin plus sodium thiosulfate (at a dose of 20 g per square meter, administered intravenously over a 15-minute period, 6 hours after the discontinuation of cisplatin) for four preoperative and two postoperative courses. The primary end point was the absolute hearing threshold, as measured by pure-tone audiometry, at a minimum age of 3.5 years. Hearing loss was assessed according to the Brock grade (on a scale from 0 to 4, with higher grades indicating greater hearing loss). The main secondary end points were overall survival and event-free survival at 3 years. RESULTS: A total of 109 children were randomly assigned to receive cisplatin plus sodium thiosulfate (57 children) or cisplatin alone (52) and could be evaluated. Sodium thiosulfate was associated with few high-grade toxic effects. The absolute hearing threshold was assessed in 101 children. Hearing loss of grade 1 or higher occurred in 18 of 55 children (33%) in the cisplatin-sodium thiosulfate group, as compared with 29 of 46 (63%) in the cisplatin-alone group, indicating a 48% lower incidence of hearing loss in the cisplatin-sodium thiosulfate group (relative risk, 0.52; 95% confidence interval [CI], 0.33 to 0.81; P=0.002). At a median of 52 months of follow-up, the 3-year rates of event-free survival were 82% (95% CI, 69 to 90) in the cisplatin-sodium thiosulfate group and 79% (95% CI, 65 to 88) in the cisplatin-alone group, and the 3-year rates of overall survival were 98% (95% CI, 88 to 100) and 92% (95% CI, 81 to 97), respectively. CONCLUSIONS: The addition of sodium thiosulfate, administered 6 hours after cisplatin chemotherapy, resulted in a lower incidence of cisplatin-induced hearing loss among children with standard-risk hepatoblastoma, without jeopardizing overall or event-free survival. (Funded by Cancer Research UK and others; SIOPEL 6 ClinicalTrials.gov number, NCT00652132 ; EudraCT number, 2007-002402-21 .).

Hypothalamic malformations in patients with X-linked deafness and incomplete partition type 3.

Patients with X-linked deafness carry mutations in the POU3F4 gene and have pathognomonic inner ear malformations characterised by symmetrical incomplete partition type 3 (absent modiolus and lamina spiralis but preserved interscalar septum in a normal-sized cochlea) and large internal auditory meatus (IAM) with an increased risk of gusher during stapes surgery. We describe a range of fairly characteristic malformations in the hypothalamus of some patients with this rare condition, ranging from subtle asymmetric appearance and thickening of the tuber cinereum to more marked hypothalamic enlargement. We discuss the role of POU3F4 in the normal development of both the inner ear and hypothalamus and the proposed pathophysiology of incomplete partition type 3.

Correction to: The CAPOS mutation in ATP1A3 alters Na/K-ATPase function and results in auditory neuropathy which has implications for management.

The following information was inadvertently omitted in the original publication.

The CAPOS mutation in ATP1A3 alters Na/K-ATPase function and results in auditory neuropathy which has implications for management.

Cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorineural hearing impairment (CAPOS) is a rare clinically distinct syndrome caused by a single dominant missense mutation, c.2452G>A, p.Glu818Lys, in ATP1A3, encoding the neuron-specific alpha subunit of the Na+/K+-ATPase α3. Allelic mutations cause the neurological diseases rapid dystonia Parkinsonism and alternating hemiplegia of childhood, disorders which do not encompass hearing or visual impairment. We present detailed clinical phenotypic information in 18 genetically confirmed patients from 11 families (10 previously unreported) from Denmark, Sweden, UK and Germany indicating a specific type of hearing impairment-auditory neuropathy (AN). All patients were clinically suspected of CAPOS and had hearing problems. In this retrospective analysis of audiological data, we show for the first time that cochlear outer hair cell activity was preserved as shown by the presence of otoacoustic emissions and cochlear microphonic potentials, but the auditory brainstem responses were grossly abnormal, likely reflecting neural dyssynchrony. Poor speech perception was observed, especially in noise, which was beyond the hearing level obtained in the pure tone audiograms in several of the patients presented here. Molecular modelling and in vitro electrophysiological studies of the specific CAPOS mutation were performed. Heterologous expression studies of α3 with the p.Glu818Lys mutation affects sodium binding to, and release from, the sodium-specific site in the pump, the third ion-binding site. Molecular dynamics simulations confirm that the structure of the C-terminal region is affected. In conclusion, we demonstrate for the first time evidence for auditory neuropathy in CAPOS syndrome, which may reflect impaired propagation of electrical impulses along the spiral ganglion neurons. This has implications for diagnosis and patient management. Auditory neuropathy is difficult to treat with conventional hearing aids, but preliminary improvement in speech perception in some patients suggests that cochlear implantation may be effective in CAPOS patients.

Cochlear re-implant rates in children: 20 years experience in a quaternary paediatric cochlear implant centre.

The aim of this study is to determine the incidence and causes for cochlear explantation/re-implantation in children as a retrospective case review in a Quaternary paediatric Cochlear Implant (CI) Centre. The subjects included in the study were Paediatric CI patients requiring cochlear explantation/re-implantation. Outcome measurements were incidence and aetiology of device explantation/re-implantation. Patient age at implantation, aetiology of deafness, CI manufacturer, and timing of explantation/re P implantation were the independent variables. 778 paediatric cochlear implants were performed in 653 children between 1992 and January 2013. There were a total of 40 (5.1%) failed implants in 38 patients. The most common reason for explantation was device failure in 22 (2.8%). Risk factors for device failure were known manufacturing defect/device recall. Medical/surgical issues accounted for 18 (2.3%) implant failures. The mean time to explantation was 3 years 10 months. The incidence of explantation/re-implantation in our paediatric cochlear implant population is comparable to other published studies. The most common reason for explantation was device failure, however, the aetiology of deafness, in particular meningitis, does not appear to increase the risk of explantation as described in previous series.

Efficacy and safety of canakinumab therapy in paediatric patients with cryopyrin-associated periodic syndrome: a single-centre, real-world experience.

OBJECTIVE: The aim of this study was to determine the short- and long-term efficacy and safety of 8-weekly canakinumab therapy in children with cryopyrin-associated periodic syndromes (CAPS) in routine clinical practice. METHODS: A single-centre observational study was performed. Patients were assessed every 8 weeks at a dedicated clinic. Standardized assessments were the 10-domains DAS for CAPS, acute phase reactants (APRs), physician's global assessment of disease activity, Child Health Assessment Questionnaire (CHAQ) and Child Health Questionnaire Parent Form 28 (CHQPF-28). The primary endpoint was clinical improvement, defined as a reduction of DAS score 8 weeks after commencing therapy. Secondary endpoints included sustained clinical improvement in APRs, relapses, CHAQ score and CHQPF-28 score. RESULTS: Ten children with CAPS [eight Muckle-Wells syndrome (MWS), two chronic infantile cutaneous neurological articular (CINCA); median age 6.3 years] received 8-weekly canakinumab treatments at 2-8.7 mg/kg for a median of 21 months (range 12-31 months). Nine of 10 patients improved after the first dose: baseline median DAS of 7.5/20 decreased to 3.5/20 at 8 weeks (P = 0.04). This clinical improvement was sustained at a median follow-up of 21 months (range 12-31 months). Children with CINCA required higher doses of canakinumab than those with MWS. CHAQ and CHQ scores indicated improvement in functioning and health-related quality of life (HRQoL). Treatment was well tolerated, with no injection site reactions and no serious infections. CONCLUSION: Canakinumab, although costly, is a safe and effective treatment for CAPS in children, leading to sustained improvement in disease activity, serological markers, functional ability and HRQoL.

Etiology of Childhood Profound Sensorineural Hearing Loss: The Role of Hearing Loss Gene Panel Testing.

OBJECTIVE: Establishing the cause of hearing loss (HL) is important and rewarding, though not without its challenges. While our ability to identify the etiology for HL has improved with advances in scientific knowledge, a significant proportion of cases remain of unknown etiology. Recent protocol changes within the NHS Genomic Medicine Service support the utilization of the HL gene panel test, rather than individual gene tests. In light of these changes, determining the yield of these more extensive panel tests is important in informing future practice. STUDY DESIGN: Retrospective study. SETTING: The Cochlear Implant (CI) Department at Great Ormond Street Hospital (GOSH). METHODS: Four hundred seventy-six children with profound HL were identified from a database of referrals to the GOSH CI Department. Data on etiology of HL including genetic diagnosis was collected from hospital notes on an electronic patient records system and hospital genetics database. RESULTS: We identified a positive result in 163/476 (34%) cases through the gene panel test, representing an additional 19% yield to current level 1 investigations. Genetic HL, including both syndromic (including those not covered by the HL gene panel) and nonsyndromic (209/476, 44%) was the most common etiology in our cohort. Perinatal, intrauterine, ototoxicity, meningitis, and encephalitis categories altogether comprised 97/476 (20%) cases. CONCLUSION: Gene panel testing provides significant additional yield over current level 1 investigations which include GJB2 testing only. This has far-reaching implications for how we optimize investigations into HL in children and counsel families, and for future early interventions.

Use of Sodium Thiosulfate as an Otoprotectant in Patients With Cancer Treated With Platinum Compounds: A Review of the Literature.

PURPOSE: Hearing loss occurs in 50%-70% of children treated with cisplatin. Scientific efforts have led to the recent approval of a pediatric formula of intravenous sodium thiosulfate (STS) for otoprotection by the US Food and Drug Administration, the European Medicines Agency, and the Medicines and Health Regulatory Authority in the United Kingdom. To inform stakeholders regarding the clinical utility of STS, the current review summarizes available literature on the efficacy, pharmacokinetics (PK), and safety of systemic STS to minimize cisplatin-induced hearing loss (CIHL). DESIGN: A comprehensive narrative review is presented. RESULTS: Thirty-one articles were summarized. Overall, systemic STS effectively reduces CIHL in the preclinical and controlled clinical study settings, in both adults and children with cancer. The extent of CIHL reduction depends on the timing and dosing of STS in relation to cisplatin. Both preclinical and clinical data suggest that systemic STS may affect plasma platinum levels, but studies are inconclusive. Delayed systemic administration of STS, at 6 hours after the cisplatin infusion, does not affect cisplatin-induced inhibition of tumor growth or cellular cytotoxicity in the preclinical setting, nor affect cisplatin efficacy and survival in children with localized disease in the clinical setting. CONCLUSION: Systemic administration of STS effectively reduces the development and degree of CIHL in both the preclinical and clinical settings. More studies are needed on the PK of STS and cisplatin drug combinations, the efficacy and safety of STS in patients with disseminated disease, and the ability of STS to prevent further deterioration of pre-established hearing loss.

Lack of significant association between mutations of KCNJ10 or FOXI1 and SLC26A4 mutations in Pendred syndrome/enlarged vestibular aqueducts.

BACKGROUND: Pendred syndrome is a common autosomal recessive disorder causing deafness. Features include sensorineural hearing impairment, goitre, enlarged vestibular aqueducts (EVA) and occasionally Mondini dysplasia. Hearing impairment and EVA may occur in the absence of goitre or thyroid dyshormonogensis in a condition known as non-syndromic EVA. A significant number of patients with Pendred syndrome and non-syndromic EVA show only one mutation in SLC26A4. Two genes, KCNJ10, encoding an inwardly rectifying potassium channel and FOXI1, a transcriptional factor gene, are thought to play a role in the disease phenotypes. METHODS: Using Polymerase Chain Reaction and Sanger sequencing, sixty-eight patients with monoallelic mutations of SLC26A4 were tested for mutations in KCNJ10 and FOXI1. RESULTS: Two variants were observed in the KCNJ10 gene, p.Arg271Cys in three patients and p.Arg18Gln in one patient; only one variant, p.Arg123Trp was observed in the FOXI1 gene in a single patient. Both p.Arg271Cys and p.Arg18Gln are likely to be polymorphisms as judged by their frequency in the general population. CONCLUSION: Therefore we found no evidence for a significant association between mutations of KCNJ10 and FOXI1 with SLC26A4. It was also observed that the variant, p.Arg271Cys in KCNJ10, previously thought to have a protective effect against seizure susceptibility, was found in a patient with Pendred syndrome with co-existing epilepsy.

Recommendations for Age-Appropriate Testing, Timing, and Frequency of Audiologic Monitoring During Childhood Cancer Treatment: An International Society of Paediatric Oncology Supportive Care Consensus Report.

IMPORTANCE: Ototoxicity is an irreversible direct and late effect of certain childhood cancer treatments. Audiologic surveillance during therapy as part of the supportive care pathway enables early detection of hearing loss, decision-making about ongoing cancer treatment, and, when applicable, the timely use of audiologic interventions. Pediatric oncologic clinical practice and treatment trials have tended to be driven by tumor type and tumor-specific working groups. Internationally accepted standardized recommendations for monitoring hearing during treatment have not previously been agreed on. OBJECTIVE: To provide standard recommendations on hearing loss monitoring during childhood cancer therapy for clinical practice. METHODS: An Ototoxicity Task Force was formed under the umbrella of the International Society of Paediatric Oncology, consisting of international audiologists, otolaryngologists, and leaders in the field of relevant pediatric oncology tumor groups. Consensus meetings conducted by experts were organized, aimed at providing standardized recommendations on age-directed testing, timing, and frequency of monitoring during cancer treatment based on literature and consensus. Consensus statements were prepared by the core group, adapted following several videoconferences, and finally agreed on by the expert panel. FINDINGS: The consensus reached was that children who receive ototoxic cancer treatment (platinum agents, cranial irradiation, and/or brain surgery) require a baseline case history, monitoring of their middle ear and inner ear function, and assessment of tinnitus at each audiologic follow-up. As a minimum, age-appropriate testing should be performed before and at the end of treatment. Ideally, audiometry with counseling before each cisplatin cycle should be considered in the context of the individual patient, specific disease, feasibility, and available resources. CONCLUSIONS AND RELEVANCE: This is an international multidisciplinary consensus report providing standardized supportive care recommendations on hearing monitoring in children undergoing potentially ototoxic cancer treatment. The recommendations are intended to improve the care of children with cancer and facilitate comparative research on the timing and development of hearing loss caused by different cancer treatment regimens.

Ototoxicity-induced hearing loss and quality of life in survivors of paediatric cancer.

INTRODUCTION: Hearing loss is a permanent and debilitating side-effect of a range of interventions commonly used in the treatment of childhood cancers, primarily ototoxic medications such as cisplatin. The purpose of this study was to examine the impact of hearing loss, in a population already at risk of reduced quality of life due to the cancer and treatment-related factors. METHODS: This study used a questionnaire specifically designed to tap issues relevant to children with hearing loss, the Paediatric Audiology Quality of Life questionnaire (PAQL). Parents of 78 children treated for a wide range of solid tumours and leukaemias completed the PAQL, 41 of whom had sensorineural hearing loss as a result of the cancer treatment. RESULTS: Significant differences between those children with hearing loss and those whose hearing remained normal were found on all four scales of the questionnaire. Children affected by ototoxicity were rated as having poorer quality of life in terms of their ability to communicate with family and peers, their independence, interactions with peers and emotional well-being. CONCLUSION: These results highlight the impact of acquired hearing loss and reinforce the importance of assessing quality of life with a measure capable of tapping the issues of consequence to the population under investigation. They also have implications for the clinical management of children during and following treatment for a wide range of cancers: medically, audiologically, psychologically and educationally.

Use of a revised children's implant profile (GOSHChIP) in candidacy for paediatric cochlear implantation and in predicting outcome.

The aims of this study were to investigate statistically the way a revised version of the children's implant profile (GOSHChIP) is used to inform candidacy decisions and explore its utility in predicting outcomes in the first three years of implant use. A retrospective case series analysis design was employed. Data were collated for 127 children with a mean age of 4.7 years at implantation. Concerns in a number of areas of the child's pre-implant functioning as rated on the GOSHChIP (spoken or manual communication skills, cognitive abilities, family structure and support, and use of hearing aids) were associated with speech perception and intelligibility outcomes following implantation. In terms of non-verbal cognitive abilities, the score on tests of fluid reasoning skills (sequencing), that contributes to the cognitive factor on the GOSHChIP, was found to significantly predict speech perception and speech intelligibility post implant. The GOSHChIP is a useful tool in making paediatric cochlear implant candidacy decisions, and in forming a guide for counselling parents about the potential benefit their child may receive from an implant.

Systematic review of cochlear implantation in CHARGE syndrome.

Objective: CHARGE syndrome presents with a collection of congenital anomalies affecting multiple organs. Ear and temporal bone anomalies, including hearing loss are highly prevalent. We present an aid to management of this challenging condition and report the strategies and outcomes of cochlear implantation. Methods: Systematic review of Medline, EMBASE, Web of Science, CENTRAL and clinicaltrials.gov was performed up to 21/10/2018 The review and meta-analysis of studies were performed according to the PRISMA statement. Patient demographics, comorbidity, anatomical factors, details of cochlear implantation and audiological outcome were extracted and summarized. Anatomical and surgical factors were evaluated by meta-analysis. Audiological outcomes reported were too heterogeneous for meta-analysis. All statistics were calculated with SPSS v23.0 (IBM, New York, USA). Results: Thirty-one studies reported 165 cochlear implants in 156 patients with CHARGE syndrome. Temporal bone and facial nerve anomalies were common. Discussion: The assessment and management of patients with CHARGE syndrome undergoing cochlear implantation is challenging. Outcomes may be affected by cochlear nerve deficiency, inner ear anomalies, and developmental delay. Surgery is almost invariably complicated by abnormal anatomy, and increased incidence of complications. Conclusion: A careful, case-by-case assessment of an individual's requirements within a multi-disciplinary setup is essential for achieving the best possible outcome.

Cochlear implantation in individuals with Usher type 1 syndrome.

OBJECTIVE: To analyze the occurrence of the Usher type 1 (USH1) gene mutations in cochlear implant recipients with deaf-blind Usher syndrome, and to assess the potential effect of these genes and other factors on the therapeutic outcome. STUDY DESIGN: Case series study of nine patients with the phenotypic diagnosis of USH1. METHODS AND SUBJECTS: Mutation analysis of four USH1 genes (MYO7A, USH1C, CDH23, and PCDH15) by single strand conformational polymorphism (SSCP) and direct sequencing methods. Pre- and post-implantation audiologic tests including pure tone audiometry, speech perception measures, and qualitative assessment of auditory performance. Nine USH1 patients who received their cochlear implants at the University of Miami Ear Institute, Miami, FL, USA, and at the Department of Cochlear Implants, Great Ormond Street Hospital for Children, London, UK. RESULTS: DNA samples from five of the nine patients were available for mutation analysis. Three of the five patients were found to carry USH1 mutations including two with a truncated mutation in CDH23 and one being a digenic inheritance with mutations in CDH23 and PCDH15. We may have failed to detect mutations in the amplicons analyzed, as neither SSCP nor direct sequencing, even combined, detects all mutations present. Our failure to detect mutations in all five patients may also confirm the genetic heterogeneity of USH1 and additional USH1 loci remain to be mapped. Pre-implantation assessment indicated that all of the subjects were pre-linguistically profoundly deaf, had no consistent response to sound, had varying degrees of auditory-oral habilitation. Age at implantation ranged from 2 to 11 years. There was post-implantation improvement in sound detection and speech recognition measures in closed-set format in all patients. Children implanted at an age of 3 years or less showed good open-set speech perception with lip-reading. All patients are implant users. Those patients who do not show open-set perception still use the cochlear implant as an adjunct of lip-reading or total communication. CONCLUSION: Testing for mutations in the USH1 genes allows early identification and intervention of children with USH1; timely intervention is important to maximize the development of useful auditory-oral communication skills prior to the onset of the visual impairment.

Expert opinion: Assessing cochlear implant candidacy and progress for people with English as an additional language.

Special considerations relating to cochlear implants (CIs) are necessary for deaf people for whom English is an additional language (EAL). The audiological and pre-linguistic skills criteria for CI candidacy are the same for children with EAL as for children from English-speaking families. However, thorough assessment is not straightforward, for example, requiring employment of experienced interpreters. To ensure family engagement and thus appropriate support in the home, clear understanding of the family's social and cultural framework and of their needs and requirements is essential. Equally, the family must be enabled to understand the implications of CI. Additional training of staff in CI teams may be needed. This article will address these and other issues for children and also consider the situation for adults.

Phonological awareness in deaf children who use cochlear implants.

A short-term longitudinal study was conducted to investigate possible benefits of cochlear implant (CI) use on the development of phonological awareness in deaf children. Nineteen CI users were tested on 2 occasions. Two groups of deaf children using hearing aids were tested once: 11 profoundly deaf and 10 severely deaf children. A battery of tests was designed to investigate syllable, rhyme, and phoneme awareness. Syllable awareness in the CI users was equivalent to that of the severely deaf group, and rhyme and phoneme awareness was similar to that of the profoundly deaf children using hearing aids. CI use affords some benefit to the development of phonological awareness. The results from this study indicate that this enhancement is first observable at the syllable level.