[Pathophysiology and genetics of deafness].
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Age Factors↗
Biomedical subjects
N Loundon
Publications and source records attributed to N Loundon.
Results of cochlear implantation in two children with mutations in the OTOF gene.
OBJECTIVE: The purpose of the study is to present the results of cochlear implantation in case of deafness involving mutations in the OTOF gene. This form of deafness is characterized by the presence of transient evoked otoacoustic emissions (TEOAE). In cases of profound deafness with preserved TEOAE, two main etiologies should be considered: either an auditory neuropathy (a retrocochlear lesion) or an endocochlear lesion. It is essential to differentiate these two entities with regards to therapy and screening. PATIENTS: We report two children who presented with profound prelingual deafness, confirmed by the absence of detectable responses to auditory evoked potentials (AEP), associated with the presence of bilateral TEOAE. Genetic testing revealed mutations in OTOF, confirming DFNB9 deafness. Both patients have been successfully implanted (with a follow-up of 18 and 36 months, respectively). MAIN OUTCOME MEASURES: Clinical (oral production, closed and open-set words and sentences list, meaningful auditory integration scale), audiometric evaluation (TEOAE, AEP) before and after implantation, and neural response telemetry (NRT). RESULTS: Both patients present a good quality of clinical responses and electrophysiological tests after implantation, indicating satisfactory functioning of the auditory nerve. This confirms the endocochlear origin of DFNB9 and suggests that these mutations in OTOF lead to functional alteration of inner hair cells. CONCLUSION: In the absence of a context of neurological syndrome, the combination of absent AEP and positive TEOAE should lead to a genetic screening for mutations in OTOF, in order to undertake the appropriate management.
Audiometry↗
Auditory neuropathy or endocochlear hearing loss?
AIMS: The purpose of the study was to define boundaries between endocochlear hearing loss and auditory neuropathy in children with congenital profound hearing loss and positive otoacoustic emissions. PATIENT: A child presented with bilateral profound hearing loss, which was confirmed by the absence of evoked auditory potentials at 110 dB and with conserved otoacoustic emissions. The lack of any relevant medical history, a normal neurologic pediatric examination, and the improvement obtained with powerful hearing aids suggested an endocochlear cause. Genetic testing identified mutations in OTOF, responsible for the DFNB9 recessive form of hearing loss. RESULTS: In recent years, cases of children with hearing loss associated with positive otoacoustic emissions have been labeled as "auditory neuropathy." Classically, this form of hearing loss is refractory to the use of hearing aids and cochlear implants. Mutations in OTOF lead to inner hair cells dysfunction, whereas the outer hair cells are initially functionally preserved. As this form of endocochlear hearing loss can be detected at a molecular level, genetic testing can be proposed for cases of nonsyndromic auditory neuropathy, as those children could benefit from cochlear implantation. CONCLUSION: It is advisable to reserve the term "auditory neuropathy" for patients who present hearing loss and conserved otoacoustic emissions in the context of a neurologic syndrome or for children with suggestive perinatal history. In other cases, genetic testing for mutations in OTOF should be carried out.
Child, Preschool↗
Cochlear implantation in children with internal ear malformations.
OBJECTIVE: To evaluate surgical aspects and results of cochlear implantation in inner ear malformations. STUDY DESIGN: Retrospective cohort study. SETTING: Ear, nose, and throat department of a tertiary referral hospital. PATIENTS: Out of 260 implanted children, 18 (6.9%) had inner ear malformations: complex cochleovestibular malformation (n = 11), common cavity (n = 1), and enlarged vestibular aqueduct (EVA) (n = 6). Deafness was progressive in 12 cases (G1) and congenital in 6 cases (G2). Genetics lead to diagnosis in 12 of 13 cases: PSD mutation (n = 11), Waardenburg syndrome (n = 1), negative (1). Mean age at implant was 7.8 years. Mean follow-up period was 48 months. MAIN OUTCOME MEASURES: Medical and surgical outcomes were reported. Closed (CSW) and open (OSW) set word perception and level of speech production were evaluated each year. The results were compared pre- and postoperatively and between the two groups. RESULTS: Gusher at surgery was observed in 50% of cases, with a persistent leak in one case. No facial injury or infectious complications were observed. At 12 months, 83% of the population had achieved more than 75% recognition in CSW, versus 16% before implant (p = 0.001). After 2 years, 64% of patients had more than 50% recognition in OSW. Good oral language was seen in 76% at 2 years and 100% at 3 years, versus 55% before implant (respectively, p > 0.05 and p = 0.03). At 1 year after implant, 83% of the G1 and 20% of the G2 achieved more than 50% recognition in OSW (p = 0.02). After 24 months, 83% of G1 and 40% of G2 had more than 50% in OSW (p > 0.05). Before implant, 75% in G1 and 0% in G2 had good oral language (p = 0.01). At 1 year, 83% in G1 and 16% in G2 had good oral language (p = 0.02). At 2 years, 100% in G1 and 20% in G2 had good oral language (p = 0.02). One child in G1 had no improvement after implantation. CONCLUSIONS: No major complication was seen. Perceptive and linguistic results were variable and depended on the type of the deafness. In progressive deafness, the perceptive and linguistic result are expected to be good. In congenital deafness, the results are more variable.
Adolescent↗
[Vestibular dysfunction after cochlear implantation: a national multicenter clinical study].
Vertigo and dizziness are the most common complications of cochlear implantation. Data of a multicentric study about clinical aspects and cost utility were collected for vertigo and dizziness: incidence, clinical and treatment were analyzed among 469 adults and children. Results demonstrated that 16% of adults and 3% of children experienced dizziness postoperatively. In a few cases a specific mechanism as perilymphatic fistula was identified. In other cases the mechanism underlying delayed vertigo remains speculative and endolymphatic hydrops was suggested.
Adolescent↗
Screening of SLC26A4 (PDS) gene in Pendred's syndrome: a large spectrum of mutations in France and phenotypic heterogeneity.
Sensorineural hearing defect and goiter are common features of Pendred's syndrome. The clinical diagnosis of Pendred's syndrome remains difficult because of the lack of sensitivity and specificity of the thyroid signs. The identification of PDS as the causative gene allowed molecular screening and enabled a re-evaluation of the syndrome to identify potential diagnostic characteristics. This report presents the clinical and genotypic findings of 30 French families, for whom a diagnosis of Pendred's syndrome had been made. Twenty-seven families had at least one mutated allele. Twenty-eight different mutations were identified, 11 of which had never been previously reported. The main clinical characteristics were: early hearing loss, fluctuation in terms of during deafness evolution, and the presence of an enlarged vestibular aqueduct.
Adolescent↗
[Cochlear implantation in the child: results and perspectives].
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Child↗
[Pediatric cochlear implants].
Indications for cochlear implants have been widened since 1995. Most implant candidates are children with severe congenital deafness. The cochlear implant must be inserted as early as possible for these children in order to optimize development of perception and language. A cochlear implant can also be discussed in certain particular cases for children with associated diseases, malformation of the inner ear, or severe deafness. The educational project must be realistic and take into account the future difficulties as well as an established set of criteria for successful language acquisition.
Acoustic Impedance Tests↗
Audiophonological results after cochlear implantation in 40 congenitally deaf patients: preliminary results.
The aim of this study is to evaluate the prognostic factors of audiophonological results in cochlear implant in congenitally deaf patients. Between 1991 and 1996. 40 congenitally deaf children underwent cochlear implantation in our department, at an average age of 7 years (median: 5 years). The results of speech therapy were evaluated with a mean follow-up of 2 years and were classified according to four criteria: perception of sound, speech perception, speech production and the level of oral language. For each criterion, a score was established ranging from zero to four. These scores were weighted according to age such that the results before and after implantation only reflected the changes related to the implantation. The prognostic factors for good results were: a good level of oral communication before implantation, residual hearing, progressive deafness and implantation at a young age. On the other hand, poor prognostic factors were: the presence of behavioral disorders and poor communication skills prior to implantation. Overall, the major prognostic factor for a good outcome appeared to be the preoperative level of oral language, even if this was rudimentary.
Adolescent↗
Head and neck infantile myofibromatosis--a report of three cases.
Infantile myofibromatosis (IM) is a proliferative disorder characterized by the development of single or multiple nodular lesions arising from cutaneous, subcutaneous, muscular, bone or visceral structures. This proliferation may occur at any anatomical site, but in 30% of the cases it involves the head and neck. We report here three cases of head and neck IM occurring in young children and presenting as solitary lesions. The clinical heterogeneity and the misleading histopathological appearances can make the diagnosis difficult. The treatment is surgical but the low rate of recurrence and the possibility of spontaneous tumoral regression may lead to conservative surgery or therapeutic abstention.
Child↗
Evolution of the bacteriologic features of persistent acute otitis media compared with acute otitis media: a 15-year study.
OBJECTIVES: To define the epidemiologic features of persistent acute otitis media (PAOM) and modifications of these features during the past 15 years and to investigate for possible differences in bacterial resistance between acute otitis media (AOM) and PAOM. DESIGN: Retrospective patient series. SETTING: Academic tertiary care center. PATIENTS AND METHODS: Persistent acute otitis media was defined as AOM lasting longer than 3 weeks despite 1 or several courses of antibiotic therapy, with the persistence of clinical and otoscopic signs of AOM. From 1982 to 1997, 475 children with PAOM were seen in our department. Every patient had 1 or several specimens of aspirations or swabs of spontaneous otorrhea (or both). Microbiologic characteristics of the isolated strains (including antibiotic susceptibility) were analyzed. Four successive series of specimens were analyzed-group 1: from October 1, 1982, to June 30, 1986 (136 patients); group 2: from January 1, 1987, to December 31, 1989 (165 patients); group 3: from January 1, 1992, to April 30, 1993 (73 patients); and group 4: from January 1, 1994, to January 31, 1997 (101 patients). During the same study periods, the bacteriologic results of patients with AOM in the same geographic region were recorded. MAIN OUTCOME MEASURES: A longitudinal comparison between the groups of patients with PAOM and a cross-comparison within each group between patients with PAOM and those with AOM. RESULTS: Obtaining repeated and multiple specimens from patients with PAOM led to a progressive decrease in the rate of sterile specimens, from 35.3% (group 1, 48 patients) to 14.9% (group 4, 15 patients) (P<.01). During this period, the prevalence of Streptococcus pneumoniae increased in patients with positive culture results, from 18.2% (group 1, 16 of 88 patients) to 44.2% (group 4, 38 of 86 patients) (P<.001). These strains rapidly and dramatically became resistant to penicillin (amoxicillin) (0% through 1989, 76.2% [16 of 21 patients] in 1993, and 97.4% [37 of 38 patients] in 1996) (P = .01). The overall prevalence of Haemophilus influenzae remained stable (between 31.4% [27 of 86 patients] and 45.4% [40 of 88 patients]), but the proportion of beta-lactamase-producing strains increased from 30.0% (group 1, 12 patients) to 55.6% (group 4, 15 patients) (P=.04). The prevalences of Pseudomonas aeruginosa and Staphylococcus aureus did not vary significantly (from 23.1% [group 2, 30 patients] to 10.7% [group 3, 6 patients] and from 10.2% [group 1, 9 patients] to 4.6% [group 4, 4 patients], respectively). Comparing data from patients with PAOM with those with AOM revealed that the increased resistance of H influenzae and, in particular, of S pneumoniae was more rapid and more marked in patients with PAOM than in those with AOM (highest rate of resistance in AOM: 36.0% [271 of 753 specimens] and 50.6% [398 of 787 specimens] for H influenzae and S pneumoniae, respectively; P<.001 for S pneumoniae). CONCLUSIONS: The increase in bacterial resistance frequently encountered during otitis media is even more marked in patients with PAOM. The identification of the organism is essential when the otitis does not resolve, especially in patients with PAOM. Obtaining repeated specimens helps to decrease the rate of sterile cultures.
Acute Disease↗
Current approach of primary tracheal dyskinesia.
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Female↗
[Neuroglial heterotopia. Apropos of 8 cases with non-nasofrontal sites].
Neuroglial heterotopia, glioma, is an uncommon congenital nervous tissue tumor, usually found in a nasofrontal localization. About 60 cases with an atypical localization, usually in the pterygomaxillary fossa have been reported. We present 8 cases. Symptomatology followed CT-scan or MRI identified localization and was helpful in orienting diagnosis before biopsy. Exeresis was difficult, particularly in deep infratemporal localizations reaching the base of the skull. The main risk is recurrence. Different surgical approaches have been discussed and should be adapted to each case.
Choristoma↗
[Screening of deafness in the young child. Value, techniques and initial results of products of acoustic distortion].
Distortion-product otoacoustic emissions are otoacoustic emissions evoked by two pure tones called primaries and proposed in order to provide a frequency specific investigation of the cochlea. This paper first reports complete input-output functions of distortion-product otoacoustic emissions for conventional audiometric frequencies in a population of 35 neonates without any risk for cochlear function. Distortion-product otoacoustic emissions could be useful, in association with evoked otoacoustic emissions and comportemental audiometry, to precisely evaluate the peripheral auditory system in infants and neonates.
Audiometry↗