N. Loundon

Cochlear Implant Failure and Revision Surgery in Pediatric Population

Objective: This study aimed to report pediatric cochlear reimplantation data focusing on failure of the device and to assess surgical challenges and functional outcomes. Methods: Retrospective case review from 1990 to 2012. Tertiary referral academic center. A retrospective review of medical and surgical records, audiologic results, and report of the manufacturer’s analysis was performed. The causes of revision cochlear implantation were divided into hard failure and soft failure. Results compared speech perception in open set or closed set words before and after revision surgery with cochlear implant only. Results: During the study period, 877 cochlear implantations were performed. Our reimplantation rate for failure of the device is 5.7% (50 of 877). The main reasons for hard failure were loss of hermeticity and cracked casing following head trauma. Surgical difficulties might be due to neo-osteogenesis related to the use of bone dust. Initial atraumatic insertion is important to ensure that revision surgeries are less problematic. In postmeningitis deafness, initial choice of electrode array is of utmost importance. We would suggest a plain shape and a larger diameter array, to ensure sufficient subsequent insertion. Post-reimplantation audiologic results were the same or better than preoperative levels in 86% of cases. Conclusion: Failure might be difficult to diagnose in children with limited language skills. The surgical team and patients should be aware of the surgical difficulties that can be encountered, especially in cases of meningitis or initial traumatic insertion. Auditory performances after reimplantation are the same or better in most cases.

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.

An Application of NGS for Molecular Investigations in Perrault Syndrome: Study of 14 Families and Review of the Literature.

Perrault syndrome (PS) is a rare autosomal recessive condition characterized by deafness and gonadic dysgenesis. Recently, mutations in five genes have been identified: C10orf2, CLPP, HARS2, HSD17B4, and LARS2. Probands included are presented with sensorineural deafness associated with gonadic dysgenesis. DNA was sequenced using next‐generation sequencing (NGS) with a panel of 35 deafness genes including the five Perrault genes. Exonic variations known as pathogenic mutations or detected with <1% frequency in public databases were extracted and subjected to segregation analysis within each family. Both mutations and low coverage regions were analyzed by Sanger sequencing. Fourteen female index patients were included. The screening in four cases has been extended to four family members presenting with PS phenotype. For four unrelated patients (28.6%), causative mutations were identified: three homozygous mutations in C10orf2, CLPP, and HARS2, and one compound heterozygous mutation in LARS2. Three additional heterozygous mutations in LARS2 and HSD17B4 were found in three independent familial cases. All these missense mutations were verified by Sanger sequencing. Familial segregation analyses confirmed the molecular diagnosis in all cases carrying biallelic mutations. Because of NGS, molecular analysis confirmed the clinical diagnosis of PS in 28.6% of our cohort and four novel mutations were found in four Perrault genes. For the unsolved cases, exome sequencing should be performed to search for a sixth unknown PS gene.

Pediatric Cochlear Implantation in Residual Hearing Candidates

Objectives: To propose categories for the various types of residual hearing in children and to review the outcomes of cochlear implantation (CI) in children with these different hearing conditions. Methods: We identified 53 children with residual hearing who had received a cochlear implant. Five groups were arbitrarily defined based on auditory features: G1, characterized by low-frequency residual hearing (n = 5); G2, characterized by severe sensorineural hearing loss (SNHL) and low speech discrimination (n = 12); G3, characterized by asymmetric SNHL (n = 9); G4, characterized by progressive SNHL (n = 15); and G5, characterized by fluctuating SNHL (n = 12). The main audiometric features and outcomes of the groups were analyzed. Results: The mean age at implantation was 10.15 years (range, 2.5-21 years). The mean preoperative score for the discrimination of open-set words was 48%; this score increased to 74% at 12 months and 81% at 24 months after the CI procedure (G1 to G5, respectively: 79/62/77%, 50/81/88%, 59/75/86%, 35/74/67%, and 39/69/80%). Children who were implanted after 10 years of age did not improve as much as those who were implanted at a younger age (open-set word list speech perception [OSW] score at 12 months: 62% vs 83%; P = .0009). Shorter delays before surgery were predictive of better performance (P = .003). Inner ear malformation and SLC26A4 mutations were not predictive of the outcome. Conclusions: CIs provide better results compared with hearing aids in children with residual hearing. Factors that may impact the benefits of CIs in patients with residual hearing are age, delay in performing the CI procedure, which ear is implanted, and initial underestimation of the patient’s hearing difficulties.

EDNRB mutations cause Waardenburg syndrome type II in the heterozygous state

Waardenburg syndrome (WS) is a genetic disorder characterized by sensorineural hearing loss and pigmentation anomalies. The clinical definition of four WS types is based on additional features due to defects in structures mostly arising from the neural crest, with type I and type II being the most frequent. While type I is tightly associated to PAX3 mutations, WS type II (WS2) remains partly enigmatic with mutations in known genes (MITF, SOX10) accounting for only 30% of the cases. We performed exome sequencing in a WS2 index case and identified a heterozygous missense variation in EDNRB. Interestingly, homozygous (and very rare heterozygous) EDNRB mutations are already described in type IV WS (i.e., in association with Hirschsprung disease [HD]) and heterozygous mutations in isolated HD. Screening of a WS2 cohort led to the identification of an overall of six heterozygous EDNRB variations. Clinical phenotypes, pedigrees and molecular segregation investigations unraveled a dominant mode of inheritance with incomplete penetrance. In parallel, cellular and functional studies showed that each of the mutations impairs the subcellular localization of the receptor or induces a defective downstream signaling pathway. Based on our results, we now estimate EDNRB mutations to be responsible for 5%–6% of WS2.

Newborn hearing screening: Prevalence and medical and paramedical treatment of bilateral hearing loss in a neonatal series in the Île-de-France region of France

OBJECTIVES We report results for newborn hearing screening in a cohort of children born in the Île-de-France region of France, as part of a national screening program set up by the French national health insurance agency. MATERIALS AND METHODS A prospective study was performed on neonates undergoing hearing screening by automated auditory brainstem response at 35 dB in maternity departments between 2005 and 2011. In case of positive findings, a further check was performed; if this was also positive in one or both ears, the child was referred to the diagnostic center. RESULTS The study recruited 27,885 births; 96% of neonates were tested. Retest was positive in 0.84% of cases. Bilateral hearing loss was diagnosed in 0.63% of infants. Fifty-nine percent of these had ≥ 1 risk factor. Hearing normalized by end of follow-up in 25% of cases. Hearing loss was moderate in 59% of hearing-impaired children, severe in 12% and profound in 29%. Mean age at hearing aid fitting ranged from 4 months in profound hearing loss to 11.4 months in moderate hearing loss. In children receiving a cochlear implant, mean age at implantation was 14 months. CONCLUSION Newborn hearing screening is now public policy. It is effective in terms of exhaustiveness, age at diagnosis and early management. Caution is appropriate in the treatment of moderate hearing loss. In case of moderate hearing loss associated with otitis media serosa, transtympanic aerators should be suggested as of the age of 6 months to enable hearing threshold measurement. Hearing aid fitting can then be considered around 9 months of age if hearing has not improved.

Speech perception, production and intelligibility in French-speaking children with profound hearing loss and early cochlear implantation after congenital cytomegalovirus infection.

OBJECTIVE To analyze speech in children with profound hearing loss following congenital cytomegalovirus (cCMV) infection with cochlear implantation (CI) before the age of 3 years. MATERIAL AND METHODS In a cohort of 15 children with profound hearing loss, speech perception, production and intelligibility were assessed before and 3 years after CI; variables impacting results were explored. RESULTS Post-CI, median word recognition was 74% on closed-list and 48% on open-list testing; 80% of children acquired speech production; and 60% were intelligible for all listeners or listeners attentive to lip-reading and/or aware of the childs hearing loss. Univariate analysis identified 3 variables (mean post-CI hearing threshold, bilateral vestibular areflexia, and brain abnormality on MRI) with significant negative impact on the development of speech perception, production and intelligibility. CONCLUSION CI showed positive impact on hearing and speech in children with post-cCMV profound hearing loss. Our study demonstrated the key role of maximizing post-CI hearing gain. A few children had insufficient progress, especially in case of bilateral vestibular areflexia and/or brain abnormality on MRI. This led us to suggest that balance rehabilitation and speech therapy should be intensified in such cases.

How to perform ABR in young children.

The diagnosis of hearing loss, especially in the context of newborn hearing screening, is mostly based on auditory brainstem response (ABR). According to the official CCAM nomenclature, ABR consists of recording early auditory evoked potentials to detect thresholds, study conduction times and measure amplitudes (corresponding to codes CDQP006 when performed without general anesthesia, and CDQP014 when performed with general anesthesia). ABR must be rigorously performed and interpreted, always in combination with a complete ENT examination and behavioral audiometry as soon as possible. In order to obtain good quality recordings, ABR must be performed with the infant totally immobile, during a nap. Several protocols can be used according to the childs age in order to obtain good quality sleep. ABR contribute to a precise hearing diagnosis, allowing early management by the first months of life.

Efficiency of Melatonin as Compared to Pentobarbital for Audiometry Brainstem Response in Children With Associated Disorders

PURPOSE Outpatient pediatric audiometry brainstem response (ABR) uses various techniques (no drug, hydroxyzine, pentobarbital, melatonin). The aim of this study was to evaluate the efficiency of melatonin as compared to pentobarbital in children with associated disorders. METHOD This was a retrospective study that took place in a tertiary care center. Eighty-three children (34 girls and 49 boys) had performed ABR under pentobarbital (GPent) or melatonin (GMel) between 2013 and 2014 and were included. All children had associated neurological or behavioral disorders or had failed a previous ABR using another technique. Success rate, defined as completed binaural investigation, delay, and duration of sleep (minutes), as well as side effects, were compared between GPent and GMel. RESULTS There were 56 patients in GMel and 27 in GPent, with a mean age at test of 3 years and 10 months (1-13 years) and 4 years and 1 month (1-14.5 years), respectively. Success rate was 76.8% and 88.8%, respectively (p > .05), sleep duration was 23 and 153 min (p < .0001), and mean delay was 35 and 54 min. No side effects have been reported. CONCLUSIONS Melatonin is a drug widely used, particularly for electroencephalogram in children. Sleep duration allowed a success rate that was comparable to pentobarbital. Melatonin seems to be an efficient alternative to pentobarbital for pediatric ABR.

Childhood psychogenic hearing loss: Identification and diagnosis

Psychogenic hearing loss, formerly known as functional or non-organic hearing loss, is a classic cause of consultation in infantile audiology. Risk factors include female gender, and age 8 or 12 years. Onset is relatively sudden, without impact on schooling or voice quality. Audiometric signs comprise non-superimposable audiometric thresholds (variable audiometric results), bilaterality, flat mean audiometric curve, and discrepancy between pure-tone and speech audiometry. The child needs reassuring during audiometric examination: attention-diversion techniques may be effective. Objective audiometry allows positive diagnosis, followed by rehabilitation and psychological care.