Application of Cervical Vestibular-Evoked Myogenic Potentials in Adults with Moderate to Profound Sensorineural Hearing Loss: A Preliminary Study

Abstract Introduction The cochlea and the vestibular receptors are closely related in terms of anatomy and phylogeny. Patients with moderate to profound sensorineural hearing loss (MPSHL) should have their vestibular organ functions tested. Objective To evaluate the incidence of vestibular abnormalities in patients with MPSHL and to study the correlation between the etiology of hearing loss (HL) and a possible damage to the labyrinth. Methods A case-control retrospective study was performed. In the case group, 20 adults with MPSHL of known etiology were included. The control group was composed of 15 adults with normal hearing. The case group was divided into 4 subgroups based on the etiology (bacterial meningitis, virus, vascular disease, congenital). Cervical vestibular-evoked myogenic potentials (cVEMPs) were used to rate the saccular function and lower vestibular nerve. Results The study was performed in 70 ears, and it highlighted the presence of early biphasic P1-N1 complex in 29 (71.5%) out of 40 ears in the study group, and in all of the 30 ears in the control group (p = 0.001). Regarding the presence or absence of cVEMPs among the four subgroups of patients with MPSHL, the data were statistically significant (p < 0.001). The comparison between the latencies and amplitude of P1-N1 in case and control groups from other studies and in the four subgroups of cases in the present study did not detect statistically significant differences. Conclusion The present study demonstrates that patients with MPSHL have a high incidence of damage to the labyrinthine organs, and it increases the current knowledge about the etiopathogenesis of sensorineural HL, which is often of unknown nature.

Frequency of GJB2 mutations in patients with nonsyndromic hearing loss from an ethnically characterized Brazilian population / Frequência de mutações de GJB2 em pacientes com perda auditiva não sindrômica em uma população brasileira etnicamente caracterizada

Abstract Introduction: In different parts of the world, mutations in the GJB2 gene are associated with nonsyndromic hearing loss, and the homozygous 35delG mutation (p.Gly12Valfs*2) is a major cause of hereditary hearing loss. However, the 35delG mutation is not equally prevalent across ethnicities, making it important to study other mutations, especially in multiethnic countries such as Brazil. Objective: This study aimed to identify different mutations in the GJB2 gene in patients with severe to profound nonsyndromic sensorineural hearing loss of putative genetic origin, and who were negative or heterozygote for the 35delG mutation. Methods: Observational study that analyzed 100 ethnically characterized Brazilian patients with nonsyndromic severe to profound sensorineural hearing loss, who were negative or heterozygote for the 35delG mutation. GJB2 mutations were detected by DNA-based sequencing in this population. Participants' ethnicities were identified as Latin European, Non-Latin European, Jewish, Native, Turkish, Afro-American, Asian and Others. Results: Sixteen participants were heterozygote for the 35delG mutation; 14 participants, including three 35delG heterozygote's, had nine different alterations in the GJB2 gene. One variant, p.Ser199Glnfs*9, detected in two participants, was previously unreported. Three variants were pathogenic (p.Trp172*, p.Val167Met, and p.Arg75Trp), two were non-pathogenic (p.Val27Ile and p.Ile196Thr), and three variants were indeterminate (p.Met34Thr, p.Arg127Leu, and p.Lys168Arg). Three cases of compound heterozygosity were detected: p.[(Gly12Valfs*2)];[(Trp172*)], p.[(Gly12Valfs*2)](;)[(Met34Thr)], and p.[(Gly12Valfs*2)(;)[(Ser199Glnfs*9)]). Conclusion: This study detected previously unclassified variants and one case of previously unreported compound heterozygosity.

Resumo Introdução: Em diferentes partes do mundo, mutações do gene GJB2 estão associadas a perda auditiva não sindrômica e a mutação homozigótica 35delG (p.Gly12Valfs*2) é uma das principais causas de perda auditiva hereditária. No entanto, a mutação 35delG não é igualmente prevalente em todas as etnias, faz com que seja importante estudar outras mutações, especialmente em países multiétnicos, como o Brasil. Objetivo: Identificar diferentes mutações no gene GJB2 em pacientes com perda auditiva neurossensorial grave ou profunda não sindrômica de origem genética putativa e negativos ou heterozigotos para a mutação 35delG. Método: Estudo observacional que analisou 100 pacientes brasileiros caracterizados etnicamente, com perda auditiva neurossensorial grave ou profunda não sindrômica, negativos ou heterozigotos para a mutação 35delG. As mutações de GJB2 foram detectadas por sequenciamento baseado no DNA nessa população. As etnias dos participantes foram identificadas como latino-europeia, não latino-europeia, judaica, nativa, turca, negra, asiática e outras. Resultados: Dezesseis participantes eram heterozigotos para a mutação 35delG e 14, incluindo três heterozigotos para 35delG, apresentaram nove alterações no gene GJB2. Uma variante, p.Ser199Glnfs*9, detectada em dois participantes, não havia sido relatada anteriormente. Três variantes eram patogênicas (p.Trp172*, p.Val167Met, e p.Arg75Trp), duas não patogênicas (p.Val27Ile e p.Ile196Thr) e três indeterminadas (p.Met34Thr, p.Arg127Leu, e p.Lys168Arg). Três casos de heterozigosidade composta foram detectados: p.[(Gly12Valfs*2)];[(Trp172*)], p.[(Gly12Valfs*2)](;)[(Met34Thr)], e p.[(Gly12Valfs*2)(;)[(Ser199Glnfs*9)]). Conclusão: Este estudo detectou variantes não classificadas anteriormente e um caso de heterozigosidade composta ainda não relatada.

Hipoacusia neurosensorial no sindrómica: caracterización molecular, desempeño auditivo y tratamiento en pacientes con mutaciones en las conexinas 26 y 30 / Non-syndromic sensorineural hearing loss: molecular characterization, auditory performance, and treatment in patients with connexin 26 and 30 mutations

La hipoacusia congénita o de aparición temprana es un trastorno sensorial muy frecuente en niños. Las causas son diversas, pueden intervenir factores genéticos y/o ambientales. El 80% de la sordera hereditaria es no sindrómica y de herencia autosómica recesiva. Hasta un 50% de estos casos se deben a mutaciones en el locus DFNB1 donde están localizados los genes GJB2 y GJB6, que codifican las conexinas 26 y 30, dos proteínas que se expresan predominantemente en la cóclea. Se han reportado más de 100 mutaciones en el gen GJB2, con una mutación muy frecuente, 35delG, que representa hasta un 85% de los alelos mutados. Una deleción en el gen GJB6, (delGJB6-D13S1830), surge como la segunda mutación más frecuente. La hipoacusia debida a mutaciones en estos genes es de inicio prelocutivo, con un grado de severidad que varía de moderado a profundo, existiendo casos leves en menor proporción, con variaciones inter e intrafamiliares. Es generalmente estable, bilateral, y afecta a todas las frecuencias. El conocimiento de las causas genéticas de la hipoacusia ha permitido contar con nuevas herramientas para el diagnóstico, y como consecuencia, se ha optimizado el asesoramiento genético y facilitado el diagnóstico precoz de los pacientes, incluso en el período prenatal. La detección precoz tiene un impacto inmediato en la implementación de terapias que permiten una estimulación auditiva temprana. En esta revisión se describe el papel de las conexinas en la fisiología auditiva, así como también las características moleculares y audiológicas y el desempeño auditivo con audífonos e implante coclear en pacientes que presentan mutaciones en las conexinas 26 y 30.

Congenital or early appearing hearing loss is a very common sensory disorder in children. The causes for the disorder are diverse and genetic as well as environmental factors may be involved. Overall, 80% of the hereditary deafness is non-syndromic and of autosomal recessive inheritance. Up to 50% of the cases are associated with mutations in the DFNB1 locus that contains the GJB2 and the GJB6 genes encoding connexins 26 and 30, two proteins that are predominantly expressed in the cochlea. More than 100 mutations of the GJB2 have been reported. The 35delG is a common mutation accounting for up to 85% of the mutated alleles. A deletion in the GJB6 gene, (delGJB6-D13S1830), is the second most frequent mutation found. Hearing loss due to mutations in these genes has an onset before speech develops and degree of severity varies from moderate to severe, with a lower incidence of mild cases and inter- and intrafamily variations. The condition is usually stable, bilateral, and affecting all frequencies. Increased knowledge on the genetic causes of hearing loss has allowed for the development of new diagnostic tools and consequently, improvement of genetic counseling and early, even prenatal, diagnosis. Early detection has an immediate impact with implementation of early auditory stimulation therapies. In this review the role of connexins in auditory physiology described, as well as molecular and audiological features and auditory performance with hearing aids and cochlear implants in patients with connexins 26 and 30 mutations.

Caracterización clínica del síndrome de Usher. Provincia Holguín / Usher syndrome clinical characterization. Holguin province

Fundamento: El síndrome de Usher es una enfermedad determinada genéticamente, con una gran heterogeneidad clínica y genética; está caracterizada por hipoacusia neurosensorial de moderada a severa, retinosis pigmentaria progresiva y puede acompañarse de alteración vestibular. Por la alta prevalencia de esta enfermedad en la provincia de Holguín, se considera necesario este estudio. Objetivo: Caracterizar clínicamente todos los enfermos con diagnóstico clínico de síndrome de Usher en la provincia Holguín, en el período de enero del 2009 a enero del 2016. Metodología: Se realizó un estudio descriptivo, retrospectivo, tipo serie de casos, a los 53 pacientes con diagnóstico clínico de síndrome de Usher en la provincia Holguín. La muestra estuvo formada por los 53 enfermos residentes en la provincia. Se revisaron los registros del Centro Provincial de Retinosis Pigmentaria y las historias clínicas de estos pacientes; se recogieron los datos de interés en un instrumento que se confeccionó para ello. Las variables estudiadas fueron el sexo, la edad, edad del diagnóstico de la hipoacusia y severidad, edad del diagnóstico de la retinosis pigmentaria y los resultados de las pruebas audiológicas, lo que permitió conocer la función vestibular. Resultados: Se caracterizó clínicamente el 100 % de los enfermos estudiados. Predominó el sexo masculino (60,37 %). El 80 % presentó la retinosis pigmentaria en la primera infancia y la hipoacusia congénita profunda en 67,92 %. Las pruebas vestibulares demostraron que el 71,70 % presenta síndrome de Usher tipo II y el 28,30 % tiene el tipo I. Conclusiones: Predominó el sexo masculino, la hipoacusia precedió a la alteración visual. Se logró caracterizar clínicamente a estos afectados. Prevaleció el síndrome de Usher tipo II.

Background: Usher syndrome is a genetically determined disease with great clinical and genetic heterogeneity. This disease is characterized by sensorineural hearing loss of moderate to severe, progressive pigmentosa retinitis and may be accompanied by vestibular alteration. At the high prevalence of this disease in the province of Holguin, this study is considered necessary. Objective: To characterize all patients clinically with clinical diagnosis of Usher syndrome in Holguin province, in the period from January 2009 to January 2016. Methodology: A series types of retrospective cases, descriptive study with 53 patients with clinical diagnosis of Usher syndrome in Holguin province was conducted. The sample consisted of 53 patients residing in the province. Provincial records Pigmentosa Retinitis Pigmentosa Center and the medical records of these patients were reviewed, the data of interest are collected in an instrument that was drawn up for these. The variables studied were sex, age, age at diagnosis of hearing loss and severity, age of diagnosis of pigmentosa retinitis and the results of the audiological tests, allowing knowing the vestibular function. Results: It was possible to clinically characterize 100 % of the patients studied, predominantly male in a 60.37 %. 80 % had pigmentosa retinitis in early childhood and profound congenital hearing loss in 67.92 %. Vestibular tests showed that 71. 70 % have Usher syndrome type II and 28.30 % have the type I. Conclusions: mainly males, hearing loss preceded visual impairment. It was possible to clinically characterize those affected. It prevailed Usher syndrome type II.

Perda auditiva unilateral em crianças: avaliação fonológica e do vocabulário / Unilateral hearing loss in children: phonology and vocabulary assessment

RESUMO Objetivo Analisar o desempenho fonológico e do vocabulário de crianças com perda auditiva unilateral. Métodos Participaram do estudo 12 crianças com perda auditiva unilateral, seis delas com perda condutiva por malformação congênita de orelha e seis com perda sensorioneural congênita ou adquirida no primeiro ano de vida, de qualquer grau, configuração, em qualquer ouvido e sem outro comprometimento associado, na faixa etária entre 3 anos e 7 meses e 7 anos e 8 meses. Foram aplicadas as provas de fonologia e vocabulário do "Teste de Linguagem Infantil - ABFW". Resultados Trinta e três por cento das crianças apresentaram desempenho diferente do esperado para a faixa etária, no que concerne ao desenvolvimento fonológico (2 crianças) e lexical (2 crianças). Na prova de fonologia, 1 criança com perda sensorioneural apresentou processos produtivos não esperados para a faixa etária (simplificações das líquidas e ensurdecimento de fricativas) e baixos índices de acertos no inventário fonético. Uma criança com perda auditiva condutiva por malformação congênita de orelha apresentou plosivação de fricativas, simplificação de líquidas e resultado limítrofe, na análise do inventário fonético (75%). Na prova de vocabulário, 2 crianças com perda sensorioneural apresentaram médias percentuais de Designação Verbal Usual abaixo das esperadas para as idades, nos diversos campos conceituais. Não houve diferença entre os grupos sensorioneural e condutivo nas provas de fonologia e de vocabulário. Conclusão Crianças com perda auditiva unilateral apresentam risco para o desenvolvimento de linguagem. Destaca-se a importância do acompanhamento de linguagem e audição neste grupo, uma vez que o monitoramento pode propiciar intervenções oportunas e eficazes, prevenindo possíveis alterações da linguagem e dificuldades escolares.

ABSTRACT Purpose To analyze the phonological and vocabulary performance of children with unilateral hearing loss. Methods Participants were twelve subjects with unilateral hearing loss of any degree and configuration, with deficit in any ear and without other associated impairments - six with conductive hearing loss due to congenital malformation of outer and/or middle ear, and six with congenital sensorineural hearing loss or acquired in the first year of life. Subjects' ages ranged from 3 years and 7 months to 7 years and 8 months. The phonology and vocabulary tasks of the "ABFW - Child Language Test" were applied. Results Thirty-three percent of the children presented performances different than expected for their age groups regarding phonological (2 children) and lexical developments (2 children). On the phonology test, one child with sensorineural hearing loss presented phonological processes that were not expected for the age group (liquid simplification and fricative devoicing) and low indices of correct production in the phonetic inventory. One child with conductive hearing loss due to malformation presented stopping and liquid simplification, and borderline results in the analysis of the phonetic inventory (75%). On the vocabulary test, two children with sensorineural unilateral hearing loss presented mean of Usual Verbal Designations below the expected for their ages in different semantic fields. There were no differences between children with sensorineural and conductive hearing loss in the phonology and vocabulary tests. Conclusion Children with unilateral hearing loss are considered at risk for language development. We emphasize the importance of language and auditory monitoring of these children, providing early and efficient interventions, thus preventing possible language disorders and learning difficulties.

P300 in individuals with sensorineural hearing loss / P300 em indivíduos com perda auditiva sensorioneural

INTRODUCTION: Behavioral and electrophysiological auditory evaluations contribute to the understanding of the auditory system and of the process of intervention. OBJECTIVE: To study P300 in subjects with severe or profound sensorineural hearing loss. METHODS: This was a descriptive cross-sectional prospective study. It included 29 individuals of both genders with severe or profound sensorineural hearing loss without other type of disorders, aged 11 to 42 years; all were assessed by behavioral audiological evaluation and auditory evoked potentials. RESULTS: A recording of the P3 wave was obtained in 17 individuals, with a mean latency of 326.97 ms and mean amplitude of 3.76 V. There were significant differences in latency in relation to age and in amplitude according to degree of hearing loss. There was a statistically significant association of the P300 results with the degrees of hearing loss (p = 0.04), with the predominant auditory communication channels (p < 0.0001), and with time of hearing loss. CONCLUSIONS: P300 can be recorded in individuals with severe and profound congenital sensorineural hearing loss; it may contribute to the understanding of cortical development and is a good predictor of the early intervention outcome. .

INTRODUÇÃO: As avaliações comportamentais e eletrofisiológicas auditivas contribuem para o entendimento do sistema auditivo e do processo de intervenção. OBJETIVO: Estudar P300 em indivíduos com perda auditiva sensorioneural severa ou profunda. MÉTODO: Estudo prospectivo transversal descritivo. Participaram 29 indivíduos, de ambos os sexos, com idade entre 18 e 45 anos com perda auditiva sensorioneural, congênita severa ou profunda e sem comorbidades, avaliados por meio de avaliação audiológica comportamental e potencial evocado auditivo de longa latência. RESULTADOS: O registro da onda P3 foi obtido em 17 indivíduos, com latência e amplitude média de 326,97 ms e 3,76V, respectivamente. Houve diferenças significativas da medida de latência em relação à idade e da amplitude segundo o grau da perda auditiva. Evidenciou-se associação do resultado do P300 aos graus de perda auditiva (p = 0,04) e ao canal de comunicação auditiva predominante (p = 0,0001) e ao tempo de privação auditiva (teste exato de Fisher). CONCLUSÕES: P300 pode ser registrado em indivíduos com perda auditiva sensorioneural congênita e colaborar para a compreensão do desenvolvimento cortical auditivo e ser preditor do resultado da intervenção. .

Programa de tamizaje universal e intervención precoz (PTUIP) en hipoacusia sensorioneural bilateral congénita: Tarea pendiente desde la perspectiva de políticas públicas de salud en Chile / Universal screening program and early intervention (uspei) in congenital bilateral sensorineural hearing loss in Chile

Congenital hearing loss is the total or partial inability to hear sounds through the ears. It is the most common disability in newborns in Chile and worldwide, and is a permanent condition. The direct impact on children who are not adequately diagnosed is the alteration in acquisition of language and cognitive skills and a decline in their social and school insertion, jeopardizing their professional and potentially productive life. Universal screening programs for hearing loss are essential for the diagnosis, since 50% of infants with hearing loss have no known risk factor. Screening before one month of age, confirmation before 3 months, and effective intervention before 6 months, allows the development of these children as if they had normal hearing. In Chile there is a selective program of screening for infants aged less than 32 weeks or 1,500 grams, as part of Explicit Health Guarantees, but it covers only 0.9% of newborns per year. Therefore, a large majority of children remain without diagnosis. The aim of this review is to compare the situation in Chile with other countries, raising the need to move towards a universal neonatal hearing loss screening program, and propose necessary conditions in terms of justification and implementation of a universal screening public policy.

Evaluación de mutaciones en los genes GJB2 y GJB6 en pacientes con sordera congénita identificados mediante screening neonatal / Evaluation of GJB2 and GJB6 gene mutation in Chilean patients with congenital deafness identified through neonatal screening

If not detected and treated early, congenital sensorineural hearing loss generates impairment in linguistic, intellectual and social development of individuals. Most congenital hearing deficits are genetic. The most common causes are mutations in GJB2 and GJB6 genes, both located on chromosome 13, encoding junction proteins that allow the transduction of sound in the inner ear. Objetive: To evaluate the presence of mutations in GJB2 and GJB6 genes in a population of children diagnosed with deafness in Complejo Hospitalario Sótero del Río since implementation of the universal newborn hearing screening program. Patients and Methods: 8 patients with congenital nonsyndromic sensorineural deafness were evaluated. Genomic DNA was extracted from oral mucosa swabs. PCR was performed to identify the 35 del G mutation in GJB2, followed by sequencing of this gene, and PCR for 2 GJB6 deletions. Results: Two patients were heterozygous for 35 del G mutation in GJB2, being their other alleles normal. Another 2 patients were heterozygous for V27I polymorphism, one of them also accompanied by p.A148A (c.444C > A) variant. A patient was found with a previously undescribed mutation (c.4360 C>T) in GJB2's intron 1, being the second allele normal. No mutations were identified in GJB6. Conclusions: In this population of children, mutations in the GJB2 gene were an identifiable cause of congenital sensorineural.

La hipoacusia neurosensorial congénita es una patología frecuente que si no es detectada y tratada oportunamente genera alteraciones en el desarrollo del niño. Desde el año 2005 se lleva a cabo en el Complejo Hospitalario Dr. Sótero del Río un programa de screening auditivo universal para la detección precoz de esta patología. La mayor parte de los déficits auditivos congénitos son genéticos. La etiología más común son las mutaciones en los genes GJB2 y GJB6, que codifican para proteínas "gap junction" que permiten la traducción del sonido en el oído interno. Objetivo: Evaluar la presencia de mutaciones de los genes GJB2 y GJB6 en una población de niños diagnosticados con hipoacusia congénita en el Complejo Hospitalario Dr. Sótero del Río a través del programa de screening auditivo universal. Pacientes y Método: Se evaluaron 8 pacientes con hipoacusia congénita neurosensorial no sindrómica. Se extrajo ADN genómico de hisopado de mucosa bucal y se realizó PCR para identificar la mutación 35 del G en GJB2, seguida de secuenciación de este gen, y PCR para 2 deleciones del gen GJB6. Resultados: Dos pacientes fueron heterocigotos para la mutación 35 del G en GJB2, siendo sus otros alelos normales. Dos fueron heterocigotos para el polimorfismo V27I; uno acompañado por la variante p.A148A (c.444 C > A). Se encontró además un paciente con una mutación no descrita anteriormente (c.4360 C>T) en el intrón 1 de GJB2, siendo su segundo alelo normal. No se identificaron mutaciones en GJB6. Conclusiones: En este grupo de niños estudiados se encontró mutaciones en el gen GJB2, causantes de sordera neurosensorial congénita.

Importance of ophthalmological examination in children with congenital sensorineural hearing loss

To evaluate the importance of ophthalmological examination in children with congenital sensorineural hearing loss [SNHL]. This study was conducted at the Ear, Nose, and Throat Department of Al-Ramadi Teaching Hospital in Al-Ramadi city, Iraq from 20 December 2007 to 30 October 2008. Fifty children with congenital SNHL were included in this prospective study. Ophthalmological examination was carried out for all patients. Out of 50 patients with SNHL, 16 [32%] had ocular abnormalities. Ocular abnormalities were more common in postlingual age group [81.3%] than other age groups, which is statistically significant [p=0.007]. Myopia was the most common abnormality that was present in 5 patients [31.3%]. The results showed that hyperopia was found in 2 patients [12.5%], squint in 2 patients [12.5%], retinitis pigmentosa 2 patients [12.5%], and blepharitis in 1 [6.3%] patient. Four other patients had multiple abnormalities: one with myopia and astigmatism, one with hyperopia and conjunctivitis, one with bilateral blepharitis, and allergic conjunctivitis, and the last one with myopia and blepharitis. Two children on examination of the eyes was diagnosed with Usher syndrome. Ocular abnormalities are a common problem in children with congenital SNHL necessitating ophthalmological examination to detect any abnormal visual acuity, and aid in the diagnosis of congenital deafness syndromes

Pendred syndrome in a large consanguineous Brazilian family caused by a homozygous mutation in the SLC26A4 gene / Síndrome de Pendred causada por mutação em homozigoze no gene SLC26A4 em uma família brasileira consangüínea

Pendred Syndrome (PS) is an autossomal recessive disorder characterized by sensorineural deafness, goiter and iodide organification defect. The hearing loss is associated with inner ear abnormalities, ranging from an isolated enlarged vestibular aqueduct (EVA) to a typical coclear dysplasia. Mutations in the gene that encodes pendrin (SLC26A4), a chloride/iodide transporter, have been shown to be associated with PS. We describe the clinical and molecular characteristics of a large consanguineous family harboring a mutation in the SLC26A4 gene. The proband was a 26-year-old deaf Brazilian woman who presented a bulky multinodular goiter and hypothyroidism since puberty. Five other siblings were deaf: one brother had a similar phenotype, three siblings also had goiters but normal thyroid function tests, and one brother had only a subtle thyroid enlargement. Other 4 siblings had no thyroid or hearing disorder. Parents were first degree cousins and had normal hearing. The mother was healthy, except for subclinical hypothyroidism; the father was deceased. A perchlorate test in the proband showed a discharge of 21 percent of the incorporated iodide 2h after the administration of 1g of KClO4. Audiological examinations showed profound hearing loss in all deaf subjects; CT and MRI of the temporal bones showed EVA in all of them. Genomic DNA was isolated from whole blood, from the 6 affected and 4 unaffected siblings, the mother and control. The coding region of the PDS gene (exons 2-21), including exon/intron boundaries, were amplified by PCR and sequenced. A single base-pair (T) deletion at position 1197 of exon 10 was detected in homozygous state in the 6 deaf siblings. The mother and 2 unaffected siblings were heterozygous for this mutation, which has been described by Everett et al. The 1197delT mutation is predicted to result in a frameshift and a truncated protein. The existence of PS phenocopies and intrafamilial phenotypic variability are...

A syndrome de Pendred (SP) é uma doença autossômica recessiva caracterizada por surdez neurossensorial, bócio e defeito de organificação do iodo. A perda auditiva está associada a anormalidades do ouvido interno, desde a dilatação isolada do aqueduto vestibular (DAV) até uma típica displasia coclear. Mutações no gene que codifica a pendrina (SLC26A4), um transportador de cloreto/iodeto, têm sido associadas à SP. Descrevemos as características clínicas e moleculares de uma grande família consangüínea portadora de uma mutação no gene SLC26A4. O caso-índice era uma paciente do sexo feminino, brasileira, 26 anos, portadora de surdez congênita, que apresentava um volumoso bócio multinodular e hipotireoidismo desde a puberdade. Outros cinco irmãos eram surdos: um irmão tinha fenotipo semelhante, três também tinham bócio, porém com função tiroideana normal e um irmão tinha apenas um discreto aumento da tiróide. Outros quatro irmãos não apresentavam alteração tiroideana ou auditiva. Os pais eram primos de primeiro grau e tinham audição normal. A mãe era saudável, exceto por hipotireoidismo subclínico; o pai era falecido. O teste do perclorato no caso-índice revelou a liberação de 21 por cento do iodo incorporado duas horas após a administração de 1 g de KClO4. Os exames audiológicos mostraram perda auditiva profunda em todos os indivíduos afetados; TC e RMN dos ossos temporais mostraram DAV em todos eles. O DNA genômico foi isolado do sangue total dos seis irmãos afetados e dos quatro não-afetados, da mãe e do controle. A região codificante do gene PDS (éxons 2-21), incluindo as junções éxon/íntron, foram amplificadas por PCR e seqüenciadas. Foi detectada a deleção de uma base (T) na posição 1197 do éxon 10, em homozigoze, nos seis irmãos afetados. A mãe e dois irmãos não-afetados eram heterozigotos para a mutação, que foi descrita inicialmente por Everett e cols. A mutação 1197delT provavelmente resulta em um erro de fase de leitura (frameshift)...

A Narrow Internal Auditory Canal with Duplication in a Patient with Congenital Sensorineural Hearing Loss

A narrow internal auditory canal (IAC) with duplication is a rare anomaly of the temporal bone. It is associated with congenital sensorineural hearing loss. Aplasia or hypoplasia of the vestibulocochlear nerve may cause the hearing loss. We present an unusual case of an isolated narrow IAC with duplication that was detected by a CT scan. In this case, the IAC was divided by a bony septum into an empty stenotic inferoposterior portion and a large anterosuperior portion containing the facial nerve that was clearly delineated on MRI.

P300 em sujeitos com perda auditiva / P300 in subjects with hearing loss

TEMA: as avaliações comportamentais e eletrofisiológicas contribuem para o entendimento do sistema auditivo e do processo de intervenção. OBJETIVO: estudar P300 em sujeitos com perda auditiva neurossensorial congênita, segundo as variáveis gênero, idade e grau da perda auditiva. MÉTODO: a presente investigação consiste em um estudo descritivo, transversal. Foram examinados 29 sujeitos, sendo 15 do gênero masculino e 14 do gênero feminino, com idade entre 11 a 42 anos. Os critérios de elegibilidade para composição da amostra foram: idade superior a 11 anos e inferior a 45 anos; ser portador de deficiência auditiva congênita severa ou profunda; não apresentar outro tipo de distúrbio; não apresentar perda auditiva central e/ou comprometimento condutivo. A primeira etapa caracterizou-se por avaliação comportamental auditiva e fisiológica que incluiu: audiometria tonal limiar (via aérea e via óssea), logoaudiometria - LDV e medidas do ganho funcional para os sujeitos que faziam uso de próteses auditivas, Imitanciometria: curva timpanométrica e pesquisa dos reflexos ipsi e contra-laterais, registro das emissões otoacústicas (EOA) - emissões otoacústicas transitórias (EOAT) e emissões otoacústicas por produto de distorção (EOAPD). A avaliação eletrofisiológica constituiu a quarta etapa do procedimento de coleta de dados e incluiu: potenciais auditivos evocados de tronco encefálico (PEATE) e de longa latência (P300). RESULTADOS: o P300 foi registrado em 17 sujeitos, com latência e amplitude média de 326,97ms e 3,76V, respectivamente. Apresentou diferenças significantes da latência em relação à idade (p < 0,03 para derivação CzA2 e p < 0,02 para derivação CzA1) e da amplitude, segundo o grau da perda auditiva (p < 0,0015). CONCLUSÃO: o P300 pode ser registrado em sujeitos com perda auditiva.

BACKGROUND: behavioral and electrophysiological evaluations contribute to the understanding of the hearing system and to the intervention process. AIM: to investigate the occurrence of P300 in subjects with congenital severe to profound hearing loss, according to the variables of gender, age and hearing loss level. METHOD: the design of this research is a descriptive transversal study. Twenty-nine subjects, 15 male and 14 female, ranging in age from 11 to 42 years, were evaluated. Inclusion criteria were: to have at least 11 years of age and no more than 45 years; to have the diagnosis of congenital severe to profound sensorineural hearing loss; to have no other disorder; and absence of central hearing loss or any other auditory conductive disorder. The first stage consisted of an auditory behavioral and physiological evaluation, including: pure tone audiometry (air and bone conduction measures), speech audiometry, SDT (Speech Detection Threshold) and functional gain measures for the subjects using hearing aids, and immittance measures - tympanometry and acoustic reflexes thresholds; transient evoked otoacoustic emissions (TEOAE); distortion product otoacoustic emissions (DPOAE). The electrophysiological evaluation was the fourth stage of the study and included: auditory brainstem response (ABR) and late latency response (P300). RESULTS: P300 was obtained for 17 out of the 29 subjects. Mean latency and amplitude were 326.97 ms and 3.76 V, respectively. A statistical significant difference was observed for latency when considering the variable age (electrode CzA2 p < 0.003 and CzA1 p < 0.02) and for amplitude when considering the variable hearing loss level (p < 0.0015). CONCLUSION: P300 can be recorded in subjects with hearing loss.

A novel G21R mutation of the GJB2 gene causes autosomal dominant non-syndromic congenital deafness in a Cuban family

Deafness is a complex disorder affecting 1/1000 infants. In developed countries, more than 50 percent of deafness cases are thought to have a genetic cause. At least 40 loci for dominant non-syndromic deafness and another 30 for recessive non-syndromic deafness have been described. Mutations in the GJB2 gene are the cause of an important number of cases of non-syndromic recessive deafness but are not as common in non-syndromic dominant deafness cases. We describe here a new dominant mutation (G21R) in the GJB2 gene which causes deafness and has been identified in a three generation Cuban family with dominant non-syndromic congenital sensorineural profound deafness.

Three dimensional magnetic resonance inner ear in meniere's disease and congential sensorineural hearing loss

This study was done on 30 patients divided into two groups: Group I [15 patients with Meniere's disease] and group II [15 patients with congenital sensorineural hearing loss [SNHL]]. Computed tomography [CT] was done for patients of congenital SNHL to exclude any bony abnormalities, then 3D MRI was done to all patients. In group I, 3D MRI showed good visualization of the membranous labyrinth, cochlea, vestibule, the semicircular canals and the endolymphatic duct and sac in all patients. In group II, CT did not show any abnormality. The 3D MRI showed good visualization of the endolymphatic sac, the semicircular canals, the internal auditory canal and the vestibular aqueduct. In one case in group II, there was enlarged endolymphatic sac [large vestibular aqueduct syndrome]. It was concluded that 3D MRI is a good method to study inner ear pathology. It is the only imaging technique that allows evaluation of the potency of the membranous labyrinth. Its thin images and high contrast allow detection of small lesions inside the IAC and any membranous labyrinth malformations. Moreover, it is the best imaging technique to detect vascular compression on the VII or VII nerves, causing SNHL, vertigo or facial paralysis

Congenital hearing impairment associated with rubella: lessons from Bangladesh.

Infection with rubella virus during pregnancy may cause fetal death or the multiple congenital fetal abnormalities that are known as congenital rubella syndrome (CRS). Studies have demonstrated that congenital hearing impairment is the most frequent abnormality associated with intrauterine rubella infection. In the present study, the first of its kind in Bangladesh, we investigated the presence of rubella antibody in hearing-impaired children in order to understand the possible role of rubella infection in the development of hearing impairment. A total of 198 hearing-impaired children and 200 children without hearing problems were studied. After taking a detailed history from the parents, blood samples were collected from both mothers and children; sera were subjected to enzyme-linked immunosorbent assay (ELISA) for anti-rubella IgG. Rubella antibody was detected in 74% of the hearing-impaired children and in 18% of those with normal hearing: this finding correlated with the presence of rubella antibody in the mothers (67%) of rubella seropositive hearing-impaired children. In contrast, we observed rubella antibody in only 14% of the mothers of the children without hearing problems. Consistent with the presence of antibody, 41% of the seropositive mothers who had hearing-impaired children gave a history of fever and rash during early pregnancy. Our study indicates a strong association between rubella infection and hearing impairment in Bangladeshi children. In addition, it also indicates that infection by rubella virus is common in Bangladesh: this suggests that priority should be given to implementing appropriate measures for the control of rubella.

Autoimmune thyroid disease in a patient with Usher's syndrome: case report

Usher's syndrome [US] is a rare genetic disorder characterized by congenital sensorineural deafness arid retinitis pigmentosa. Here, we describe the association of US and hypothyroidism due to autoimmune thyroid disease [AITD] in a 50-year-old Kuwaiti woman diagnosed clinically to have US. As far as we are aware, this is the first case report of US in Kuwait arid to our knowledge the association with AITD has not been previously reported

Síndrome de Waardenburg tipo II: a propósito de dos casos clínicos / Waardenburg's syndrome type II: a propose of 2 clinical cases

El Síndrome de Waardenburg representa la forma más común de sordera congénita; es una condición pleitrópica, autosómica dominante, con penetrancia y expresividad variable. Se describen dos casos clínicos de Síndrome de Waardenburg tipo II. Las principales manifestaciones son la sordera sensorioneural congénita, alteraciones de la pigmentación pilosa y cutánea, puente nasal ancho, hipertricosis de las cejas, mandíbula cuadrada, encanecimiento prematuro y alteraciones neurológicas. Se revisan los criterios de diagnóstico de la enfermedad y los hallazgos asociados descritos de la literatura

Semiologia neurológica numa populaçäo de crianças deficientes auditivas / Neurologic semiology in a population of hearing impaired children

Foi constituída uma amostra aleatória de 42 crianças deficientes auditivas neurossensoriais congênitas, profundas e bilaterais, com idade cronológica variando entre 4 e 7 anos, que frequentavam classes de habilitaçäo da cidade de Campinas. As criançs propostas foram comparadas com dois grupos controles de 42 crianças, da mesma faixa etária, de classe comum. Todas foram submetidas ao exame neurológico tradicional. Verificou-se que os aspectos que demonstraram diferenças foram o perímetro craniano e o tono muscular. Nos demais itens avaliados, mostrou-se hiperatividade motora, síndrome cerebelar e síndrome ocular, porém näo houve diferença significativa entre os dois grupos