Age impact on the eferent system actitivies in cochlear mechanical properties in normal hearing individuals
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Data
2009-06-01
Autores
Oliveira, Jerusa Roberta Massola de
Fernandes, João Candido [UNESP]
Costa Filho, Orozimbo Alves
Título da Revista
ISSN da Revista
Título de Volume
Editor
Associação Brasileira de Otorrinolaringologia e Cirurgia Cervicofacial
Resumo
O trato olivococlear medial realiza o controle eferente das células ciliadas externas, regulando as contrações lentas e atenuando as rápidas. Com a pesquisa da amplitude das emissões otoacústicas sem e com estimulação acústica contra, ipsi ou bilateralmente, é possível estimar as condições desse trato, uma vez que o efeito resultante de redução/supressão das emissões indica seu funcionamento. O envelhecimento implica em diminuição da atividade do sistema auditivo central, em função da degeneração das estruturas envolvidas nas habilidades auditivas. OBJETIVO: O objetivo foi investigar o efeito da idade na atividade do trato sobre a cóclea, com a análise da amplitude das emissões com estimulação acústica contralateral. MATERIAL E MÉTODO: A casuística foi composta por 75 indivíduos agrupados conforme a idade. A metodologia foi o modo convencional, com clique linear e o ruído branco. ESTUDO DE CASO: A análise considerou a resposta das orelhas e a comparação entre os grupos. RESULTADOS: Os resultados revelam diferenças estatisticamente significantes entre o response das emissões sem e com estimulação acústica contralateral, nos indivíduos (20 a 39 anos). O efeito redução/supressão das emissões diminui com a idade (quarta década). CONCLUSÃO: O envelhecimento prejudica a efetividade da atividade do trato.
The medial olivocochlear tract has efferent control over the outer hair cells, regulating the slow contractions and damping the fast ones. Using ipsilateral, contralateral or bilateral otoacoustic emissions amplitude studies, it is possible to estimate the conditions of this tract, since the effect resulting from the reduction/suppression of these emissions indicate the tract's functioning. Aging implies an activity reduction in the central auditory system, because of the degeneration of the structures involved in hearing skills. AIM: our goal was to investigate the effects of age on the activities of this tract on the cochlea, through the analysis of the emissions' amplitude with contralateral acoustic stimulation. MATERIALS and METHODS: Our series was made up of 75 individuals grouped according to age. The methodology was conventional, with a linear click and a white noise. CASE STUDY: the analysis considered the response from both ears and the comparison between the groups. RESULTS: the results show a statistically significant difference between the emissions' response with and without contralateral acoustic stimulation in the individuals between 20 and 39 years of age. The emissions reduction/suppression effect reduced with age (fourth decade). CONCLUSION: aging impairs the tract effectiveness.
The medial olivocochlear tract has efferent control over the outer hair cells, regulating the slow contractions and damping the fast ones. Using ipsilateral, contralateral or bilateral otoacoustic emissions amplitude studies, it is possible to estimate the conditions of this tract, since the effect resulting from the reduction/suppression of these emissions indicate the tract's functioning. Aging implies an activity reduction in the central auditory system, because of the degeneration of the structures involved in hearing skills. AIM: our goal was to investigate the effects of age on the activities of this tract on the cochlea, through the analysis of the emissions' amplitude with contralateral acoustic stimulation. MATERIALS and METHODS: Our series was made up of 75 individuals grouped according to age. The methodology was conventional, with a linear click and a white noise. CASE STUDY: the analysis considered the response from both ears and the comparison between the groups. RESULTS: the results show a statistically significant difference between the emissions' response with and without contralateral acoustic stimulation in the individuals between 20 and 39 years of age. The emissions reduction/suppression effect reduced with age (fourth decade). CONCLUSION: aging impairs the tract effectiveness.
Descrição
Palavras-chave
audição, envelhecimento, órgão de corti, hearing, aging, organ of corti
Como citar
Brazilian Journal of Otorhinolaryngology. Associação Brasileira de Otorrinolaringologia e Cirurgia Cervicofacial, v. 75, n. 3, p. 340-344, 2009.