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Introduction Riluzole (2-amino-6-trifluoromethoxy benzothiazole) is known as a neuroprotective, antioxidant, antiapoptotic agent. It may have beneficial effects on neuronal cell death due to cisplatin-induced ototoxicity. Objective To evaluate the effect of riluzole on cisplatin-induced ototoxicity in guinea pigs. Methods Twenty-four guinea pigs, studied in three groups, underwent auditory brainstem response evaluation using click and 8 kHz tone burst stimuli. Subsequently, 5 mg/kg of cisplatin were administered to all animals for 3 days intraperitoneally (i.p.) to induce ototoxicity. Half an hour prior to cisplatin, groups 1, 2 and 3 received 2 ml of saline i.p., 6 mg/kg of riluzole hydrochloride i.p., and 8 mg/kg of riluzole hydrochloride i.p., respectively, for 3 days. The auditory brainstem responses were repeated 24 hours after the last drug administration. The cochleae were analyzed by transmission electron microscopy (TEM). Results After drug administiration, for 8,000 Hz stimulus, group 1 had significantly higher threshold shifts when compared with groups 2 ( p < 0.05) and 3 ( p < 0.05), and there was no significant difference in threshold shifts between groups 2 and 3 ( p > 0.05). Transmission electron microscopy findings demonstrated the protective effect of riluzole on the hair cells and the stria vascularis, especially in the group treated with 8 mg/kg of riluzole hydrochloride. Conclusion We can say that riluzole may have a protective effect on cisplatin- induced ototoxicity. However, additional studies are needed to confirm these results and the mechanisms of action of riluzole.
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ABSTRACT INTRODUCTION: ANSD is a challenging problem. OBJECTIVE: To present our experience on management of the children with ANSD with respect to clinical data. METHODS: This retrospective study included all children younger than 16 years of age who applied to the department between 2005 and 2013 (with the exception of newborn hearing screening NHS referrals). The data were derived from pure tone, OAEs and ABR tests, and further medical risk factors of the subjects were evaluated. RESULTS: ANSD was recognized in 74 ears of 40 children (B/U: 34/6) among 1952 children with SNHL (2.04%) detected among 9520 applicants to the department (0.42%). The clinical tests revealed that hearing loss greater than 15 dB was present in both ears of 38 cases. The degree of hearing loss was profound in 48% children, severe in 12% children, moderate in 28% children, mild in 10% children and normal in 5% children. ABRs were absent/abnormal in 37/3 ears and CMs were detected in all. Acoustic reflexes were absent in all ears. Rehabilitation was managed by CI and hearing aids in 15 and 23 cases, respectively. FM system was given to two cases displaying normal hearing but poor speech discrimination in noisy environments. CONCLUSION: ANSD is a relatively challenging problem for the audiology departments because of its various clinical features and difficulties in management. Our patients with ANSD most commonly displayed profound hearing loss. The number of overlooked cases may be minimized by performing ABR and OAE in every case referred with the suspicion of hearing loss.
Resumo Introdução: Espectro da neuropatia auditiva ainda é uma condição clínica desafiadora. Objetivo: Apresentar nossa experiência no tratamento de crianças com espectro da neuropatia auditiva em relação aos dados clínicos. Método: Este estudo retrospectivo incluiu crianças menores de 16 anos de idade que deram entrada no departamento entre 2005 e 2013 (com exceção de encaminhamentos para triagem auditiva neonatal). Foram avaliados os dados obtidos a partir dos exames de audiometria tonal, emissões otoacústicas (EOA), potencial evocado auditivo de tronco encefálico (ABR) e outros fatores de risco. Resultados: Das 1.952 crianças com perda auditiva neurossensorial (2,04%) detectadas dentre os 9.520 candidatos que deram entrada no departamento (0,42%), espectro da neuropatia auditiva foi reconhecida em 74 orelhas de 40 crianças (B/U: 34/6). Os testes clínicos revelaram que uma perda auditiva superior a 15 dB estava presente em ambas as orelhas em 38 casos. O grau de perda auditiva das crianças era profundo em 48%, grave em 12%, moderado em 28%, leve em 10%, e normal em 5%. ABR estava ausente/anormal em 37/3 orelhas e microfonia coclear foi detectado em todas as crianças. Reflexos acústicos estavam ausentes em todas as orelhas. A reabilitação foi tratada com implante coclear e aparelhos auditivos em 15 e 23 casos, respectivamente. Um sistema FM foi utilizado em dois casos que apresentavam audição normal, mas discriminação deficiente da fala em ambientes ruidosos. Conclusão: Espectro da neuropatia auditiva é um problema desafiador para os departamentos de audiologia, devido às suas várias características clínicas e dificuldades no tratamento. Em nossos pacientes a perda auditiva profunda foi a mais frequente. O número de casos negligenciados pode ser diminuído com a realização dos exames ABR e EOA em todos os casos encaminhados com suspeita de perda auditiva.
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Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Perda Auditiva Central/reabilitação , Perda Auditiva Neurossensorial/reabilitação , Reflexo Acústico , Audiometria de Tons Puros , Índice de Gravidade de Doença , Estudos Retrospectivos , Potenciais Evocados Auditivos do Tronco Encefálico , Emissões Otoacústicas Espontâneas , Perda Auditiva Central/diagnóstico , Perda Auditiva Neurossensorial/diagnósticoRESUMO
ABSTRACT INTRODUCTION: Hyperbilirubinemia is a common health problem in newborns. Its effects can be different according to the level and duration of the hyperbilirubinemia. The toxic effect of bilirubin on the auditory system can be seen as a sensory neural hearing loss or auditory neuropathy spectrum disorder (ANSD). OBJECTIVE: The purpose of our study was to determine the effects of toxic bilirubin level on the auditory system by using Auditory Brainstem Response audiometry. METHODS: Rats are used as animal models due to their low cost and easy attainability. Auditory Brainstem Response was used for auditory assessment. In this study, three groups were established: experimental, control and placebo groups. RESULTS: In the experimental group, which consists of rats with hyperbilirubinemia, sensory neural hearing loss was found bilaterally in 4 rats (66.67%) and unilaterally in 2 rats (16.67%) and auditory neuropathy spectrum disorder was found unilaterally in 1 rat (8.33%). Auditory Brainstem Response thresholds were significantly elevated compared to control and placebo groups (p < 0.05). CONCLUSION: Hyperbilirubinemia of newborn rats may result both in sensory neural hearing loss and auditory neuropathy spectrum disorder.
RESUMO INTRODUÇÃO: A hiperbilirrubinemia é um problema de saúde comum em neonatos. Seus efeitos podem variar, dependendo do nível e da duração da hiperbilirrubinemia. O efeito tóxico da bilirrubina no sistema auditivo pode ser observado na forma de deficiência auditiva sensorioneural ou de distúrbio do espectro da neuropatia auditiva. OBJETIVO: A finalidade de nosso estudo foi determinar os efeitos de nível tóxico de bilirrubina no sistema auditivo, com o uso da audiometria da resposta auditiva evocada de tronco cerebral. MÉTODO: Os ratos são empregados como modelos animais graças a seu baixo custo e fácil obtenção. Utilizamos a resposta auditiva evocada de tronco cerebral para avaliação da audição. No estudo, foram estabelecidos três grupos: experimental, controle e placebo. RESULTADOS: No grupo experimental, constituído de ratos com hiperbilirrubinemia, disacusia auditiva neurosensorial foi diagnosticada bilateralmente em quatro ratos (66,67%), e unilateralmente em dois (16,67%); e distúrbio do espectro da neuropatia auditiva foi observado unilateralmente em um rato (8,33%). Os limiares da resposta evocada de tronco cerebral estavam significantemente elevados, em comparação com os grupos controle e placebo (p < 0,05). CONCLUSÃO: A hiperbilirrubinemia de ratos neonatos pode resultar tanto em disacusia auditiva neurosensorial como em distúrbio do espectro da neuropatia auditiva.
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Animais , Masculino , Ratos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Potenciais Evocados Auditivos/fisiologia , Perda Auditiva Neurossensorial/fisiopatologia , Hiperbilirrubinemia Neonatal/fisiopatologia , Animais Recém-Nascidos , Audiometria , Modelos Animais de Doenças , Perda Auditiva Neurossensorial/etiologia , Hiperbilirrubinemia Neonatal/complicações , Ratos WistarRESUMO
INTRODUCTION: ANSD is a challenging problem. OBJECTIVE: To present our experience on management of the children with ANSD with respect to clinical data. METHODS: This retrospective study included all children younger than 16 years of age who applied to the department between 2005 and 2013 (with the exception of newborn hearing screening NHS referrals). The data were derived from pure tone, OAEs and ABR tests, and further medical risk factors of the subjects were evaluated. RESULTS: ANSD was recognized in 74 ears of 40 children (B/U: 34/6) among 1952 children with SNHL (2.04%) detected among 9520 applicants to the department (0.42%). The clinical tests revealed that hearing loss greater than 15dB was present in both ears of 38 cases. The degree of hearing loss was profound in 48% children, severe in 12% children, moderate in 28% children, mild in 10% children and normal in 5% children. ABRs were absent/abnormal in 37/3 ears and CMs were detected in all. Acoustic reflexes were absent in all ears. Rehabilitation was managed by CI and hearing aids in 15 and 23 cases, respectively. FM system was given to two cases displaying normal hearing but poor speech discrimination in noisy environments. CONCLUSION: ANSD is a relatively challenging problem for the audiology departments because of its various clinical features and difficulties in management. Our patients with ANSD most commonly displayed profound hearing loss. The number of overlooked cases may be minimized by performing ABR and OAE in every case referred with the suspicion of hearing loss.
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Perda Auditiva Central/reabilitação , Perda Auditiva Neurossensorial/reabilitação , Adolescente , Audiometria de Tons Puros , Criança , Pré-Escolar , Potenciais Evocados Auditivos do Tronco Encefálico , Feminino , Perda Auditiva Central/diagnóstico , Perda Auditiva Neurossensorial/diagnóstico , Humanos , Lactente , Masculino , Emissões Otoacústicas Espontâneas , Reflexo Acústico , Estudos Retrospectivos , Índice de Gravidade de DoençaRESUMO
INTRODUCTION: Hyperbilirubinemia is a common health problem in newborns. Its effects can be different according to the level and duration of the hyperbilirubinemia. The toxic effect of bilirubin on the auditory system can be seen as a sensory neural hearing loss or auditory neuropathy spectrum disorder (ANSD). OBJECTIVE: The purpose of our study was to determine the effects of toxic bilirubin level on the auditory system by using Auditory Brainstem Response audiometry. METHODS: Rats are used as animal models due to their low cost and easy attainability. Auditory Brainstem Response was used for auditory assessment. In this study, three groups were established: experimental, control and placebo groups. RESULTS: In the experimental group, which consists of rats with hyperbilirubinemia, sensory neural hearing loss was found bilaterally in 4 rats (66.67%) and unilaterally in 2 rats (16.67%) and auditory neuropathy spectrum disorder was found unilaterally in 1 rat (8.33%). Auditory Brainstem Response thresholds were significantly elevated compared to control and placebo groups (p<0.05). CONCLUSION: Hyperbilirubinemia of newborn rats may result both in sensory neural hearing loss and auditory neuropathy spectrum disorder.
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Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Potenciais Evocados Auditivos/fisiologia , Perda Auditiva Neurossensorial/fisiopatologia , Hiperbilirrubinemia Neonatal/fisiopatologia , Animais , Animais Recém-Nascidos , Audiometria , Modelos Animais de Doenças , Perda Auditiva Neurossensorial/etiologia , Hiperbilirrubinemia Neonatal/complicações , Masculino , Ratos , Ratos WistarRESUMO
INTRODUCTION: Mucopolysaccharidosis is a hereditary lysosomal storage disease, which develops due to a deficiency in the enzymes that play a role in the metabolism of glycosaminoglycans (GAG). The incidence of mucopolysaccharidosis is 1/25,000, with autosomal recessive inheritance (except for MPS II). Mucopolysaccharidosis occurs in seven different types, each with a different congenital deficiency of lysosomal enzymes. In mucopolysaccharidosis patients, even though progression of clinical findings is not prominent, the disease advances and causes death at early ages. Facial dysmorphism, growth retardation, mental retardation, and skeletal or joint dysplasia are the most frequently found symptoms in these patients. OBJECTIVE: The purpose of our study is to present the types of hearing loss types and tympanometric findings of patients with mucopolysaccharidosis referred to our clinic with suspicion of hearing loss. METHODS: After otorhinolaryngological examination, 9 patients with different types of mucopolysaccharidosis, underwent to immittance and audiometric evaluations, performed according to their physical and mental abilities, and ages, in order to determine their hearing thresholds. RESULTS: The audiometric findings of the 9 patients followed with mucopolysaccharidosis were reported separately for each case. CONCLUSION: Based on the high frequency of hearing loss in mucopolysaccharidosis patients, early and detailed audiological evaluations are highly desirable. Therefore, regular and systematic multidisciplinary evaluations are very important.