Maturação do sistema auditivo central em crianças ouvintes normais

Abstract

Background: the long latency auditory evoked potentials (LLAEP) provide objective data about the function of hearing cortical structures. Aim: to characterize the maturation of the central hearing system in normally hearing children. Method: record of LLAEP of fifty-six subjects with hearing tresholds within normal limits, of both genders, being 46 children and 10 adults. With the availability of two recording channels, one was directed to register the LLAEP and the other, to record the artifact generated by ocular movement, aiming at its control. The potentials were recorded with subjects in an alert state, through electrodes positioned in Cz (active) and A2 (reference), and the ocular movements, through electrodes in the left supra and infra-orbital positions; the ground electrode was placed in A1. The morphology and the values of latency and of amplitude for components P1, N1 and P2, according to age, were analyzed. In order to verify the reproducibility of the recorded potentials, a double blind study was carried out, by introducing the analysis of another evaluator. Results: the double blind study did not present statistically significant differences between the analyses. With the increase in age there was an improvement in the morphology and a decrease in the latency values of components P1, N1 and P2. Also there was a decrease in the amplitude of component P1 and no variation in the amplitude values was observed for components N1 and P2. No statistically significant difference was observed between genders. Conclusion: the maturational process of the central hearing system occurs gradually, being the greatest changes observed when comparing children and adults. Key Words: Hearing; Maturation; Auditory Evoked Potentials. ResumoTema: os potenciais evocados auditivos de longa latência (PEALLs) fornecem dados objetivos sobre a funcionalidade das estruturas centrais auditivas. Objetivo: caracterizar a maturação do sistema auditivo central em crianças com audição normal. Método: registro dos PEALLs de 56 indivíduos ouvintes normais, de ambos os sexos, sendo 46 crianças e 10 adultos. Com a disponibilidade de dois canais de registro, um foi destinado à captação dos PEALLs e outro, ao registro do artefato gerado pelo movimento ocular, visando ao seu controle. Os potenciais foram registrados com os indivíduos em estado de alerta, por meio de eletrodos posicionados em Cz (ativo) e A2 (referência) e os movimentos oculares, por eletrodos em posição supra e infra-orbital esquerda; o eletrodo terra foi colocado em A1. Foram analisados a morfologia e os valores de latência e amplitude dos componentes P1, N1 e P2, de acordo com a idade. Para verificar a reprodutibilidade dos registros, foi realizado um estudo duplo-cego com a introdução da análise de outra avaliadora. Resultados: o estudo duplo-cego não mostrou diferenças estatisticamente significantes entre as análises. Com o avanço da idade, houve melhora na morfologia e diminuição nos valores de latência dos componentes P1, N1 e P2. O componente P1 teve sua ampl...

Editorial

“…Tendo como pressuposto a afirmação de que os potenciais evocados auditivos de longa latência (PEALLs) fornecem dados objetivos sobre a funcionalidade das estruturas centrais auditivas, o objetivo do estudo apresentado por Ventura et al (2009) foi caracterizar a maturação do sistema auditivo central em 56 crianças com audição normal. Os resultados obtidos sugerem que o processo maturacional do sistema auditivo central acontece de maneira gradativa, sendo as maiores modificações observadas ao se comparar crianças e adultos.…”

“…Considering that the long latency auditory evoked potentials (LLAEP) provide objective data about the function of hearing cortical structures, the purpose of the study presented by Ventura et al (2009) was to characterize the maturation of the central hearing system in 56 normally hearing children. The obtained results suggest that the maturational process of the central hearing system occurs gradually, being the greatest changes observed when comparing children and adults.…”

Audição e linguagem em crianças nascidas a termo e pré-termo

“…CAEP emerged as a procedure that is able to measure the degree of maturation of the central auditory pathways in an objective way by analyzing the changes concerning morphology and latency values of P1-P2-N1 components, over time (4,5) . In newborns and smaller children, P1 and N1 are the predominant potentials (5,6) . On the other hand, the onset of other components would be related to the progressive maturation of central auditory pathways (5,6) .…”

“…In newborns and smaller children, P1 and N1 are the predominant potentials (5,6) . On the other hand, the onset of other components would be related to the progressive maturation of central auditory pathways (5,6) . It is noteworthy that the wave P1 was established as a biomarker to evaluate the auditory maturation (7,8) .…”

“…It is noteworthy that the wave P1 was established as a biomarker to evaluate the auditory maturation (7,8) . This component is a positive wave, generated by the thalamocortical circuit activity in the stimulation of sounds, being a measure that is capable of reflecting changes in central auditory nervous system (CANS), resulting from the neuronal plasticity (6) . It is also worth noting that the presence of waves in CAEP can be considered an indicator of cognitive development, especially in preterm infants, who are considered at risk for changes in auditory processing and in language (9) .…”