Congenital hearing loss: a literature review of the genetic etiology in a Mexican population.

Hearing loss is the most frequent sensory disorder, with an incidence of 1:1500 live newborns. In more than 50% of patients, it is associated with a genetic cause, while in up to 30% of cases, it is related to syndromic entities. We performed a literature review of studies on congenital hearing loss of genetic origin in the Mexican population. We identified eight reports that showed that the pathogenic variants most frequently associated with hearing loss are related to the GJB2 gene, although in a low percentage (3%). Other mutations were identified in the GJB6, SLC26A4, or CHD23 genes. On this basis, a possible diagnostic strategy in Mexican patients with hearing loss is to consider an initial screening of these three genes. If these genes were negative for pathogenic variants, the following steps would be to consider second-generation sequencing analysis focused on panels of genes associated with hearing loss, isolated or syndromic, and if necessary, to perform exome or whole-genome analysis. Establishing an etiologic cause is critical in clinically evaluating patients with congenital hearing loss and their families. It can help determine rehabilitation strategies, such as hearing aids or cochlear implants and provide information on disease progression and genetic counseling in this population.

La pérdida auditiva es la alteración sensorial más frecuente, con una incidencia de 1:1500 recién nacidos vivos. En más del 50% de los pacientes se asocia con una causa genética, mientras que en más del 30% de los casos se asocia con entidades sindrómicas. Se llevó a cabo una revisión de la literatura de las investigaciones sobre la pérdida auditiva congénita de origen genético en la población mexicana. Se identificaron ocho reportes en los que se demostró que las variantes patogénicas más frecuentemente asociadas con pérdida auditiva se encuentran en el gen GJB2, aunque en un porcentaje bajo (3%). Se identificaron otras mutaciones en los genes GJB6, SLC26A4 o CHD23. Con base en esta información, una posible estrategia diagnóstica en pacientes mexicanos con pérdida auditiva es considerar un primer paso en el tamiz diagnóstico con los tres genes mencionados. Si estos genes fueran negativos para variantes patogénicas, el siguiente paso sería considerar el análisis por secuenciación de segunda generación enfocado en paneles de genes asociados con pérdida auditiva, tanto aislada como sindrómica, y en caso necesario, realizar el análisis del exoma o del genoma completo. Establecer una causa etiológica es un componente crítico en la evaluación clínica de los pacientes con pérdida auditiva congénita, ya que puede ayudar a determinar las estrategias de manejo y rehabilitación, como el uso de auxiliares auditivos o implantes cocleares, proporcionar información sobre la progresión de la enfermedad y dar asesoramiento genético en esta población.

Influência da habilidade comunicacional dos pais nas orientações de saúde ao filho surdo / Influence of parents' communication skills on health guidelines for deaf children / Influencia de las habilidades de comunicación de los padres en las pautas de salud para niños sordos

Objetivo: verificar a influência da comunicação dos pais no recebimento de informações e comportamento de saúde de filhos surdos. Método: estudo transversal realizado com 110 pessoas surdas, selecionadas com a técnica snowball sampling, em municípios no Noroeste do estado do Paraná. Os dados foram coletados de fevereiro a agosto de 2019, mediante aplicação de instrumento estruturado. Na análise dos dados utilizou-se a estatística descritiva e inferencial. Resultados: a maioria dos surdos (95,4%) recebeu alguma orientação de saúde no núcleo familiar; ser orientado sobre a importância de consultas de rotina mostrou-se associado à realização da mesma pelos filhos no último ano (OR= 3,40). O pai que sabe se comunicar em Libras constituiu fator de proteção, pois, nestes casos, ocorreram mais orientações sobre o uso de drogas e consumo abusivo de açúcar. Conclusão: a habilidade comunicacional dos pais possibilita que eles realizem mais orientações relacionadas à saúde e isto influencia o comportamento em saúde de filhos surdos.

Objective: to ascertain the influence of parents' communication on deaf children's reception of health information, and health behavior. Method: in this cross-sectional study of 110 deaf people selected by snowball sampling in municipalities in northwest Paraná state, data were collected from February to August 2019 using a structured instrument. Descriptive and inferential statistics were used in the data analysis. Results: most deaf people (95.4%) received some health guidance in the family; being guided about the importance of routine appointments was found to be associated with the children's attending such appointments in the prior year (OR = 3.40). The parent able to communicate in Libras was a protective factor, because in these cases, more guidance on drug use and sugar abuse occurred. Conclusion: the parents' communication skills enabled them to provide more health-related guidance, and this influenced their deaf children's health behavior.

Objetivo: determinar la influencia de la comunicación de los padres en la recepción de la información sanitaria y el comportamiento sanitario de los niños sordos. Método: en este estudio transversal de 110 personas sordas seleccionadas por muestreo de bola de nieve en municipios del noroeste del estado de Paraná, los datos se recolectaron de febrero a agosto de 2019 mediante un instrumento estructurado. Se utilizó estadística descriptiva e inferencial en el análisis de datos. Resultados: la mayoría de las personas sordas (95,4%) recibió alguna orientación sanitaria en la familia; Se descubrió que el hecho de recibir orientación sobre la importancia de las citas de rutina estaba asociado con la asistencia de los niños a dichas citas el año anterior (OR = 3,40). El padre capaz de comunicarse en Libra fue un factor de protección, porque en estos casos, hubo más orientación sobre el uso de drogas y el abuso de azúcar. Conclusión: las habilidades de comunicación de los padres les permitieron brindar más orientación relacionada con la salud, y esto influyó en el comportamiento de salud de sus hijos sordos.

Deafness and Vestibulopathy in Cerebellar Diseases: a Practical Approach.

Cerebellar ataxias are a clinically heterogeneous group of neurological disorders. Besides the cerebellum, several forms of hereditary ataxias or non-genetic ataxias also affect other areas of the brain. Some forms of cerebellar ataxias may have cochlear and vestibular involvement and may present with deafness and symptoms or signs of vestibulopathy (dizziness, nystagmus and diplopia). Recognizing otoneurological symptoms in patients with cerebellar ataxias is mandatory, since these signs may guide a specific diagnosis, and clinicians may provide a suitable therapeutic approach. In this review, we describe and discuss the most common forms of cerebellar ataxias associated with deafness and vestibulopathy.

Effect of GJB2 235delC and 30-35delG genetic polymorphisms on risk of congenital deafness in a Chinese population.

Congenital deafness is a serious and irreversible condition in humans. The GJB2 gene is implicated in the pathogenesis of autosomal recessive nonsyndromic hearing loss. Its 235delC and 30-35delG polymorphisms are reported to be associated with risk of hereditary deafness. However, the effect of the interaction between GJB2 235delC and 30-35delG and environmental factors on congenital deafness has not been described. Therefore, we performed a case-control study to investigate the influence of these polymorphisms on congenital deafness risk, and their interaction with maternal and other environmental factors in the development of this disease. Between March 2014 and May 2015, 118 patients with congenital deafness and 242 healthy controls were enrolled into our study. Compared with the GG genotype, the adjusted odds ratios (ORs) [and 95% confidence intervals (CIs)] for the 235delC GC and CC genotypes were 4.66 (1.77-13.07) and 8.28 (2.06-47.52), respectively. Individuals harboring the GC+CC genotypes were at a greatly increased risk of congenital deafness compared to those with the GG genotype (OR = 5.65, 95%CI = 2.54-13.18). However, no significant relationship was established between the 30-35delG variant and this disease. The 235delC polymorphism exhibited an interaction with use of aminoglycoside antibiotics during pregnancy in conferring susceptibility to congenital deafness (chi-square = 8.76, P = 0.003). In conclusion, our study suggests that the GJB2 235delC polymorphism, but not the 30-35delG variant, contributes to congenital deafness susceptibility in the Chinese population examined, and demonstrates an interaction with consumption of aminoglycoside antibiotics during pregnancy in exerting this effect.

Hospitalizations Attributable to Respiratory Infections among Children with Neurologic Disorders.

OBJECTIVES: To characterize respiratory infection hospitalizations in children with neurologic disorders and to compare them with those of the general pediatric population. STUDY DESIGN: We analyzed claims data from commercial insurance and Medicaid enrollees < 19 years of age from July 2006 to June 2011 who had ≥ 1 visit with an International Classification of Diseases, Ninth Revision, diagnosis code for a neurologic disorder. We identified hospitalizations with primary diagnosis codes indicating a respiratory infection and compared hospitalization rates with random samples of children from the commercial and Medicaid databases (comparison groups). RESULTS: Among 33,651923 children, 255,046 (0.76%) had ≥ 1 neurologic condition. Among children with neurologic conditions, 8249 of 68,717 hospitalizations (12%) were attributed to a respiratory infection (rate: 21/1000 person-years), although rates varied by disorder. Children with neurologic disorders had greater rates than children in comparison groups (relative rate: Commercial Claims 7.4 [95% CI 7.1-7.7]; Medicaid 5.0 [95% CI 4.8-5.2]). Children < 2 years were most likely to be hospitalized, although those 10-18 years were 14.5 (95% CI 13.3-16.7) times more likely to be hospitalized than age-matched comparison groups. Co-occurring deafness, blindness, and scoliosis were associated with increased respiratory hospitalization rates. CONCLUSIONS: Children with neurologic disorders are at 5- to 7-fold greater risk for hospitalization from respiratory infections compared with all children, although rates vary widely by disorder type, age, and comorbidities. Children with specific neurologic disorders and those who had co-occurring conditions have the highest rates.

Processo de diagnóstico da surdez em crianças na percepção de familiares e gestores / Process diagnosis of deafness in children in the perception of familiar and managers

OBJETIVO: Analisar a percepção de familiares e gestores (educação e saúde) sobre o processo de diagnóstico da surdez em crianças de um município do Paraná. MÉTODOS: A coleta de dados deu-se a partir da técnica de grupo focal formado por dez pais e por entrevista aberta individual com gestores. A análise do material extraído foi feita por meio do estudo do conteúdo na modalidade temática. A discussão dos dados foi organizada pela análise das falas dos sujeitos. RESULTADOS: Foi possível extrair duas grandes categorias temáticas: frustração no processo de diagnóstico, acolhimento e orientação; dificuldades na relação intersetorial Saúde e Educação. CONCLUSÃO: Os desdobramentos da surdez diagnosticada tardiamente permearam os âmbitos relacionados à saúde e à educação das crianças com surdez. O diagnóstico precoce e o acolhimento adequado não ocorreu na maioria das crianças e verificou-se que a relação intersetorial (saúde e educação) é insatisfatória.

PURPOSE: To analyze the perception of family and managers (education and health) on the process of diagnosis of deafness in children in a city in Paraná. METHODS: The analysis of the material gathered in the focus groups and on the interviews was made based on the analysis of content of the thematic mode. The discussion of the data was organized based on the analysis of the subjects' testimonies. RESULTS: The thematic categories were: the early diagnosis and hearing health as a human right; and the necessity of adequate support and initial guidance; challenges in the inter-sector and inter-network relations. CONCLUSION: We have reached the conclusion that the repercussions of a late deafness diagnosis have influence in health and education aspects of the deaf children's life. Early diagnosis and adequate support did not happen with the majority of the children. An inadequate inter-sector relation between Health and Education municipal authorities was verified.

The importance of fundus eye testing in rubella-induced deafness.

OBJECTIVE: The purpose of this study was to establish a new approach to improve detection of deafness due to rubella. METHODS: Colombian institutes for the deaf were visited by a medical team to perform in all enrolled individuals an ophthalmological examination with emphasis in fundus eye by a retina specialist. In cases where ocular alterations compatible with CRS were found, a medical interview by a clinical geneticist analyzing pre-and postnatal history and a thorough medical examination was done. RESULTS: A total of 1383 deaf institutionalized individuals were evaluated in 9 Colombian cities in the period of 2005 to 2006, finding a total of 463 positive cases for salt-and-pepper retinopathy (33.5%), in which rubella could be the etiology of deafness. Medellin, Cartagena, Bucaramanga and Barranquilla were the cities with the highest percentage of Congenital rubella, corresponding to 22.8% of analyzed population. The analysis performed on cases in which reliable prenatal history was obtained in a second appointment (n=88) showed association between positive viral symptoms during pregnancy and salt-and-pepper retinopathy in 62.5% of cases, while both (retinopathy and viral symptoms) were absent in 29.5% of cases; showing a correlation in 92% of cases. CONCLUSIONS: The frequency of deafness by rubella obtained by this study is significantly high compared with previous Colombian studies and with international reports. It was possible to correlate the antecedent of symptoms during pregnancy with the presence of salt-and-pepper retinopathy in this deaf population when reliable prenatal history was available, therefore eye testing with emphasis in fundus examination is a good indicator of rubella induced deafness. We propose a new approach in the search of deafness causes, based on a thorough ophthalmologic examination in all deaf people.

[Genetics of congenital deafness]. / Genética de la sordera congénita.

Congenital deafness is defined as the hearing loss which is present at birth and, consequently, before speech development. It is the most prevalent sensor neural disorder in developed countries, and its incidence is estimated between 1-3 children per 1,000 newborns, of which more than 50% are attributable to genetics causes. Deafness can be classified as syndromic or non-syndromic. In the first case, it is associated with outer ear malformations and/or systemic findings. More than 400 syndromes accompanied of deafness have been described, which represent about 30% of cases of congenital hearing loss. The remaining percentage corresponds to non-syndromic cases: 75-85% are autosomal recessive, 15-24% are autosomal dominant, and 1-2% are X-linked. The evaluation of a child with deafness requires a multidisciplinary collaboration among specialists, who must coordinate themselves and give information to the affected family. The aims of establishing a diagnosis are to predict other manifestations that may suggest some syndrome and to anticipate their management, as well as to perform genetic counseling to parents and affected individuals.

Paget's disease of bone: analysis of 134 cases from an island in Southern Brazil: another cluster of Paget's disease of bone in South America.

Paget's disease of bone (PDB) exhibits a marked geographic variation. In Brazil, the prevalence of PDB is unknown and only a few clinical data are available. The aim is to determine clinical, laboratory, imaging and response to treatment data in a large PDB case series in the city of Florianopolis, Brazil. We have performed a retrospective study based on charts reviews of all patients with PDB followed at the University Hospital of the Federal University of Santa Catarina and at five different private rheumatology outpatient offices in Florianopolis, between 1995 and 2009. One hundred and thirty-four patients with PDB were identified. Mean age at diagnosis was 63.2 ± 10.5 years, 67.2% were women, and 91.1% were Caucasian. Positive family history was reported in only 8.2%. Polyostotic disease was found in 75.0% of the cases, bone pain in 77.9%, and bone deformities in 15.9%. Higher levels of AP were significantly associated with polyostotic disease and skull involvement. Pelvic bones were the most frequently affected (53.7%). Complications included deafness in 8.2%, bone fractures in 3.0%, hydrocephalus in 2.2%, and cauda equina syndrome in 0.7% of the cases. Treatment with zoledronic acid achieved the best response with only 2.9% failing to respond adequately. According to literature data, PDB in South America seems to be characterized by an overall low prevalence, but with localized clusters with higher prevalence. The authors have described a cluster of PDB in Florianopolis, in Southern Brazil. Further properly designed studies are necessary to clarify the PDB epidemiology in South America.

Causas de sorderas profundas en niños chilenos asistentes a escuelas especiales para sordos / Causes of severe deafness in Chilean children enrolled in special schools for the deaf

La relación entre la audición y el desarrollo del lenguaje ha sido ampliamente demostrada, se aprende a hablar imitando los sonidos oídos y dándole la interpretación que oralmente los padres enseñan. Por ello, todos los países se están esforzando por realizar un tamizado universal en neonatos. El Estado de Chile, en un primer esfuerzo por detectar tempranamente las sorderas, está aplicando un tamizado auditivo a neonatos de alto riesgo. No hay en Chile estudio sobre las causas de sorderas, por lo cual se decidió investigar sobre esta materia en un grupo de niños sordos que estudia en alguna de las 4 escuelas especiales de Santiago. Conociendo las causas de sorderas congénitas y las de instalación en la infancia temprana, posibilita su prevención en el control del embarazo y de niño sano. Objetivo: Establecer las causas de sorderas profundas, según los conocimientos de sus padres o tutor legal y ficha escolar, en niños y jóvenes estudiantes de escuelas especiales para sordos. Material y método: En este estudio observacional, el universo fueron todos los niños que asisten a 4 escuelas especiales para sordos en Santiago. La muestra estuvo constituida por 315 casos que representan al 92 por ciento del universo. Se revisaron las fichas escolares de estos niños y la información se contrastó y completó con una entrevista a los padres o tutores. Conclusiones: El 63 por ciento de los niños presentaba sordera congénita, entre ellos el 9 por ciento fue por infección materna. Del total de la población, el 41.5 por ciento presentó sordera congénita de causa desconocida; el 13 por ciento fue adquirida por meningitis y en el 5.8 por ciento de los casos por prematurez.

The relationship between hearing and language development has been widely demonstrated, as children learn to speak by imitating sounds and interpreting them as they are orally taught by their parents. Because of this, countries are trying to put more emphasis on universal screening of newborns. In Chile, the first efforts of early detection of deafness have been in screening high risk newborns. En Chile there are no studies on the causes of deafness, and for this reason the present study seeks to investigate this issue in a group of Deaf children in special schools in Santiago. Understanding the causes of congenital and early childhood deafness allows for better prevention during pregnancy and early childhood. Objective: Establish the causes of severe deafness, according to the knowledge of parents or legal guardians and school records, in young students in special schools for the Deaf. Materials and Methods: In this observational study, the universe consisted of all children that attend 4 special schools for the Deaf in Santiago. The sample consisted of 315 cases, which represent 92 percent of the universe. School records were examined and information was contrasted and completed with and interview with parents or guardians. Conclusions: 63 percent of children suffered from congenital deafness, 9 percent of those due to infection during pregnancy. In 41.5 percent of all cases the cause of deafness was unknown. 13 percent was due to meningitis, and 5.8 percent was due to prematurity.

Comparação dos indicadores de risco para surdez em neonatos encontrados nos anos de 1995 e 2005 / Comparison of indicators of risk of deafness in newborns studied in the years 1995 and 2005

Introdução: Os dados apresentados pelo Centro de Vigilância Epidemiológica do Estado de São Paulo apontam que o número de crianças acometidas por doenças infecto-contagiosas aumenta a cada ano. Algumas dessas doenças são consideradas de risco para a audição. Objetivo: Verificar e comparar a ocorrência de indicadores de risco para Deficiência Auditiva durante o intervalo de 10 anos em uma maternidade de São Paulo. Método: Estudo de caráter quantitativo e retrospectivo, realizado a partir do levantamento e análise de dados dos registros fornecidos por uma maternidade da cidade de São Paulo. Foram levantados os registros dos bebês que nasceram de janeiro a dezembro dos anos de 1995 (n=2.077) e 2005 (n=5.129), e inclusos os que apresentaram indicadores de risco para surdez como prematuridade, baixo peso e asfixia, além de possuir diagnóstico confirmado ou suspeita de doenças infecto-contagiosas do grupo TORSCH-A. Resultados: Foram considerados os prontuários de 565 crianças nascidas em 1995, e de 1047 em 2005. Dentre os indicadores de risco para surdez, observou-se diferença significativa para o indicador prematuridade e asfixia, não havendo diferença significativa para o indicador baixo peso. Os indicadores de risco prematuridade, baixo peso e asfixia foram mais frequentes que a Toxoplasmose, a Sífilis e o HIV+. As crianças nascidas em 1995 tenderam a ter um maior número de indicadores de risco e/ou doenças do que as nascidas em 2005 (p<0,001). Conclusão: A maior incidência de indicadores em 1995 aponta melhoria na saúde, diminuindo ao longo de 10 anos o índice de recém-nascidos com risco para surdez.

Introduction: The data submitted by the Center of Epidemiological Surveillance of the State of São Paulo indicates the number of children affected by infecto-contagious diseases increases yearly. Some of these diseases are considered to be of risk for hearing. Objective: Check and compare the occurrence of risk indicators of the Hearing Loss during the interval of 10 years in a maternity of São Paulo. Method: Quantitative and retrospective study carried out from the research and review of data of registers supplied by a maternity of the city of São Paulo. We surveyed the registers of babies who were born from January through December of the years of 1995 (n=2.077) and 2005 (n=5.129), including those who had risk indicators for deafness and prematurity, low weight and asphyxia, besides having a diagnosis confirmed or suspicion of infecto-contagious diseases of group TORSCH-A. Results: We reviewed reports of 565 children born in 1995, and 1047 born in 2005. Among the risk indicators of deafness, we noticed a significant difference for the indicator of prematurity and asphyxia and there was no significant difference for the low weight indicator. The risk indicators of prematurity, low weight and asphyxia were more frequent than Toxoplasmosis, Syphilis and HIV+. The children born in 1995 tended to have a higher number of risk indicators and/or diseases than those born in 2005 (p<0.001). Conclusion: The major incidence of indicators in 1995 appoints an improvement to health that diminishes the index of newborns with risk of deafness along 10 years.

Newborn hearing screening and genetic testing in 8974 Brazilian neonates.

OBJECTIVE: An early diagnosis has been a priority in the audiological practice. Identifying hearing loss until 3 months old through Universal Newborn Hearing Screening and intervention before 6 months old, minimize the impact of auditory loss in the health and communication development of these children. However, in the clinical practice, despite the help of the risk indicators in the audiological and etiological diagnosis, the integrated services have come up against the challenge of determining the causes of auditory loss, bearing in mind that approximately 50% of the subjects who have congenital loss do not show risk factors in their clinical history. The current research aims introduce together etiologic and audiological diagnosis of newborns. METHODS: We eluted dried blood spots from paper and performed genetic testing for 35delG mutation in 8974 newborns that were also screened for transient otoacoustic emissions (TOAE). In addition, the A1555G and A827G mutations in the MTRNR1 mitochondrial gene were screened in all newborns. RESULTS: We have found 17 individuals who failed in TOAE. Among them, we detected 4 homozygous newborns for 35delG mutation and 3 individuals with A827G mutation in the MTRNR1 mitochondrial gene. The frequency of 35delG carriers was 0.94% [84/8974]. In all 17 individuals who failed in OAE no other mutation besides those mentioned above was found. CONCLUSIONS: The results greatly contribute to the public health area indicating the etiologic diagnosis, allowing family counseling as well as the early rehabilitation treatment or surgical intervention. Over time that will help to reduce the costs of rehabilitation considerably.

Prevalence of DFNB1 mutations in Argentinean children with non-syndromic deafness. Report of a novel mutation in GJB2.

OBJECTIVE: Mutations in DFNB1 locus, containing GJB2 (connexin 26) and GJB6 (connexin 30) genes, are the most common cause of autosomal recessive non-syndromic hearing loss. More than 100 mutations in GJB2 have been reported worldwide. Two deletions in GJB6, del(GJB6-D13S1830) and del(GJB6-D13S1854), have been found to be frequent in the Spanish population. The aim of this study was to determine the prevalence of GJB2 mutations and both GJB6 deletions in Argentinean children with non-syndromic deafness. METHODS: This study included 94 unrelated children with moderate to profound non-syndromic sensorineural hearing impairment. Molecular analysis was performed using a tiered approach. All DNA samples were screened for c.35delG mutation by PCR/RFLP. Samples from patients who were not homozygous for c.35delG were analysed for the presence of GJB6 deletions by PCR multiplex. The samples that remained unresolved after screening were further analysed by direct sequencing of GJB2 coding region. Finally, the splice site mutation IVS1+1G-->A was analysed by PCR/RFLP. RESULTS: Sequence variations in the GJB2 and GJB6 genes were found in 49 of the 94 unrelated patients. The most prevalent GJB2 mutation, c.35delG, was found in 40 of the 68 pathogenic alleles with the second most common allele being p.R143W (4/68). Fourteen sequence variations other than c.35delG were identified. Seven already described mutations were present in more than one allele; among them, IVS1+1G-->A, the rare splice site mutation flanking exon 1. In addition to known disease-related alterations, a novel GJB2 mutation, c.262G>C (p.A88P), was also identified. Six alleles were identified carrying GJB6 deletions; the most prevalent was del(GJB6-D13S1830). The frequency of the latter was found to be as high as that found in Spain from where Argentina has received one of its major immigration waves. CONCLUSIONS: The overall frequency of GJB2/GJB6 mutations in the present sample is in agreement with other Caucasian populations. As expected, c.35delG was the most prevalent mutation. The deletion del(GJB6-D13S1830) was the second most common mutation. These findings reinforce the importance of the study of GJB2/GJB6 genes in diagnosis to provide early treatment and genetic counselling.

Tamizaje universal de hipoacusia en el recién nacido / Universal screening of newborn hypoacusis

Neonatal hearing loss affects 1-3 from every 1000 live newborns. For optimal language and social development, proper diagnosis and treatment must be established before the first 6months of age. In Chile, screening for hearing loss is only performed on high-risk newborns weighting less than 1500 grams. However, about half of the newborns with hearing loss have no risk factors. Given the importance of this disability and the fact that it can be effectively diagnosed, a universal detection program for hearing loss becomes necessary. Further more, effective treatments for hearing loss, like hearing aids and cochlear implants are available in several institutions of our country, including the Clinical Hospital of the University of Chile. Worldwide, the most used screening methods are otoacoustic emissions and auditory brainstem evoked responses, the former, a test that detects the acoustic energy generated by the outer hair cells of the cochlea in response to a brief sound, and the latter a test that measures neural responses of the central auditory pathway. Both are objective and non-invasive techniques. Here we review evidences that support the need of creating a universal newborn hearing screening program in Chile.

Prevalence of early neurodevelopmental disabilities in Mexico: a systematic review.

OBJECTIVE: Early neurodevelopment disabilities (END) such as cerebral palsy (CP), deafness, blindness, epilepsy, and mental retardation (MR) are very important public health concerns. Although no strong data on END can be obtained in Mexico, the few papers concerning END epidemiology deserve systematic and critical review. Thus, this was the objective of the present paper. METHOD: We performed a systematic review of papers published reporting on the prevalence of END in Mexico. We performed a search in several medical data bases such as PubMed, Artemisa, ImBioMed, and LiLaCS. Each paper was downloaded, read and discussed. We only selected papers published between 1999 and 2008. RESULTS: No data on CP and epilepsy prevalence in infants have been found. Data on deafness prevalence report hearing loss in 0.65/1,000 healthy newborns, and in 2.6/100 in high-risk very premature infants. With regard to blindness, prevalence of retinopathy of premature infants in any stage was reported at ca 10.61 and 22.2/100 in high-risk premature infants. Congenital hypothyroidism (CH) prevalence in infants was found in 4.2/10,000 live newborns after a national universal screening survey. CONCLUSION: No universal data regarding the prevalence of END in Mexico have been investigated, with the exception of CH. Mexico needs more research to determine epidemiologic data focused on designing actions to prevent, treat, and rehabilitate END.

Prevalence of early neurodevelopmental disabilities in Mexico: a systematic review / Prevalencia de neuro-discapacidades tempranas en México: una revisión sistemática

OBJECTIVE: Early neurodevelopment disabilities (END) such as cerebral palsy (CP), deafness, blindness, epilepsy, and mental retardation (MR) are very important public health concerns. Although no strong data on END can be obtained in Mexico, the few papers concerning END epidemiology deserve systematic and critical review. Thus, this was the objective of the present paper. METHOD: We performed a systematic review of papers published reporting on the prevalence of END in Mexico. We performed a search in several medical data bases such as PubMed, Artemisa, ImBioMed, and LiLaCS. Each paper was downloaded, read and discussed. We only selected papers published between 1999 and 2008. RESULTS: No data on CP and epilepsy prevalence in infants have been found. Data on deafness prevalence report hearing loss in 0.65/1,000 healthy newborns, and in 2.6/100 in high-risk very premature infants. With regard to blindness, prevalence of retinopathy of premature infants in any stage was reported at ca 10.61 and 22.2/100 in high-risk premature infants. Congenital hypothyroidism (CH) prevalence in infants was found in 4.2/10,000 live newborns after a national universal screening survey. CONCLUSION: No universal data regarding the prevalence of END in Mexico have been investigated, with the exception of CH. Mexico needs more research to determine epidemiologic data focused on designing actions to prevent, treat, and rehabilitate END.

OBJETIVO: Las neuro-discapacidades tempranas (NDT) como la parálisis cerebral (PC), hipoacusia, debilidad visual, epilepsia y retardo mental (RM) son problemas muy importantes de salud pública. Aunque no existen suficientes datos sobre la prevalencia de NDT en México, el objetivo de este trabajo es hacer comentarios sistemáticos y críticos sobre los ya estudios existentes. MÉTODO: Realizamos una búsqueda sistemática de artículos publicados sobre NDT en México. La búsqueda comprendió las siguientes bases de publicaciones: PubMed, Artemisa, ImBioMed y LiLaCS. Cada artículo fue descargado, leído cuidadosamente y comentado. Se seleccionaron aquellos trabajos publicados entre 1999-2008. RESULTADOS: No se han publicado datos sobre la prevalencia de PC y epilepsia en niños mexicanos. La prevalencia de hipoacusia se ha reportado entre 0.65/1,000 en recién nacidos sanos y 2.6/100 en recién nacidos de alto riesgo. La prevalencia de retinopatía de la prematurez como indicador de debilidad visual ha sido reportada entre 10.61-22.2/100 recién nacidos de alto riesgo. La prevalencia de hipotiroidismo congénito (HC) como indicador de RM ha sido encontrada en 4.2/10,000 recién nacidos en el estudio nacional de tamizaje. CONCLUSIÓN: No hay datos sobre la prevalencia de NDT con la excepción del HC en México. Se necesita más investigació.

Screening, diagnosing and treating deafness: the knowledge and conduct of doctors serving in neonatology and/or pediatrics in a tertiary teaching hospital.

CONTEXT AND OBJECTIVE: Infant hearing deficiency is a human disorder with devastating effects and serious implications for the development of speech and language. Early diagnosis of hearing loss should be the objective of a multidisciplinary team, and early-intervention programs should immediately follow this. The aim of this study was to investigate the knowledge and conduct of pediatricians and pediatric residents in a tertiary teaching hospital regarding deafness. DESIGN AND SETTING: Cross-sectional study in a tertiary hospital in the state of São Paulo, Brazil. METHODS: Eighty-eight questionnaires were randomly distributed to pediatricians and pediatric residents. RESULTS: Thirty-six questionnaires were analyzed. Most respondents (61.1%) were residents in pediatrics and/or neonatology. Eighty-three percent of them performed special procedures on babies presenting a high risk of deafness, and 55% reported that they had no knowledge of techniques for screening hearing. Most of them were unaware of the classifications of level and type of hearing loss. According to 47.2% of them, infants could begin to use a hearing aid at six months of age. Most of them reported that infants could undergo hearing rehabilitation during the first six months of life, and all respondents stated 's responsibilities. CONCLUSIONS: Even though most of the participants followed special procedures with babies presenting a high risk of deafness, they did not routinely investigate hearing. All respondents believed that it is a doctor's responsibility to be concerned about child communication.

Screening, diagnosing and treating deafness: the knowledge and conduct of doctors serving in neonatology and/or pediatrics in a tertiary teaching hospital / Avaliação, diagnóstico e tratamento da surdez: conhecimento e conduta de médicos com atuação em neonatologia e/ou pediatria de um hospital-escola terciário

CONTEXT AND OBJECTIVE: Infant hearing deficiency is a human disorder with devastating effects and serious implications for the development of speech and language. Early diagnosis of hearing loss should be the objective of a multidisciplinary team, and early-intervention programs should immediately follow this. The aim of this study was to investigate the knowledge and conduct of pediatricians and pediatric residents in a tertiary teaching hospital regarding deafness. DESIGN AND SETTING: Cross-sectional study in a tertiary hospital in the state of São Paulo, Brazil. METHODS: Eighty-eight questionnaires were randomly distributed to pediatricians and pediatric residents. RESULTS: Thirty-six questionnaires were analyzed. Most respondents (61.1 percent) were residents in pediatrics and/or neonatology. Eighty-three percent of them performed special procedures on babies presenting a high risk of deafness, and 55 percent reported that they had no knowledge of techniques for screening hearing. Most of them were unaware of the classifications of level and type of hearing loss. According to 47.2 percent of them, infants could begin to use a hearing aid at six months of age. Most of them reported that infants could undergo hearing rehabilitation during the first six months of life, and all respondents stated 's responsibilities. CONCLUSIONS: Even though most of the participants followed special procedures with babies presenting a high risk of deafness, they did not routinely investigate hearing. All respondents believed that it is a doctor's responsibility to be concerned about child communication.

CONTEXTO E OBJETIVO: A deficiência auditiva na criança é uma das desordens humanas cujo impacto tem efeito devastador produzindo sérias conseqüências no desenvolvimento da fala e linguagem. O diagnóstico precoce da perda auditiva deve ser objetivo de uma equipe interdisciplinar e ser seguido imediatamente por programas de intervenção precoce. O objetivo foi investigar o conhecimento e condutas de pediatras e residentes em pediatria de um hospital-escola terciário em relação à surdez. TIPO DE ESTUDO E LOCAL: Estudo transversal, hospital terciário do Estado de São Paulo. MÉTODOS: Oitenta e oito questionários distribuídos para pediatras e residentes em pediatria. RESULTADOS: Analisados 36 questionários. A maioria dos entrevistados (61,1 por cento) foi de residentes em pediatria e/ou neonatologia. Oitenta e três por cento realizavam alguma conduta especial com bebês de alto risco para surdez, e 55 por cento referiram não ter conhecimento sobre técnicas de triagem auditiva. A maioria desconhecia as classificações de grau e tipo de perda auditiva. Para 47,2 por cento, a criança poderia utilizar o aparelho auditivo a partir de seis meses. A maioria referiu que a criança poderia realizar reabilitação auditiva nos primeiros seis meses de vida e todos os entrevistados responderam que é função do médico ter preocupação com a comunicação da criança. CONCLUSÕES: Mesmo a maioria adotando condutas especiais com bebês de alto risco para surdez, não se investigava rotineiramente a audição. Todos os entrevistados julgaram ser função do médico se preocupar com a comunicação da criança.

Neurosensory disabilities at school age in geographic cohorts of extremely low birth weight children born between the 1970s and the 1990s.

OBJECTIVE: To contrast the rates of neurosensory disabilities at age 8 years in extremely low birth weight (ELBW; birth weight 500 to 999 g) children born in the state of Victoria, Australia in 4 four distinct eras from the late 1970s to the late 1990s. STUDY DESIGN: Study subjects were assessed at age 8 years. Results were compared among 4 ELBW cohorts (87 of 89 children born in 1979-1980, 206 of 212 born in 1985-1987, 224 of 241 born in 1991-1992, and 160 of 170 born in 1997), and between each of these ELBW cohorts and normal birth weight (NBW; birth weight > 2499 g) controls. RESULTS: The survival rate for ELBW children rose from 25% for the 1979-1980 cohort to 73% for the 1997 cohort. No statistically significant differences in the disability rates were seen in the 4 eras; however, in the 1997 cohort, disability rates were significantly higher in the ELBW children compared with NBW controls: mild disability, 36.7% vs 9.8%; moderate disability, 10.1% vs 2.3%; and severe disability, 8.2% vs 0.6%. CONCLUSIONS: The survival rate of ELBW children continues to rise over time. Despite this, however, the rates of disability in these vulnerable children at school age have remained stable and high relative to controls.

Blood pressure, anti-hypotensive therapy, and neurodevelopment in extremely preterm infants.

OBJECTIVE: To compare neurodevelopment (ND) in 3 cohorts of extremely preterm infants: untreated with normal blood pressure (BP), untreated with low BP, and treated with low BP. STUDY DESIGN: We conducted a retrospective study of infants 23 to 25 weeks gestation. Low BP was defined as >or=3 mean arterial pressures