Auditory response of the reticular nucleus of thalamus in awake mice / 生理学报

This study aims to explore the auditory response characteristics of the thalamic reticular nucleus (TRN) in awake mice during auditory information processing, so as to deepen the understanding of TRN and explore its role in the auditory system. By in vivo electrophysiological single cell attached recording of TRN neurons in 18 SPF C57BL/6J mice, we observed the responses of 314 recorded neurons to two kinds of auditory stimuli, noise and tone, applied to mice. The results showed that TRN received projections from layer six of the primary auditory cortex (A1). Among 314 TRN neurons, 56.05% responded silently, 21.02% responded only to noise and 22.93% responded to both noise and tone. The neurons with noise response can be divided into three patterns according to their response time: onset, sustain and long-lasting, accounting for 73.19%, 14.49% and 12.32%, respectively. The response threshold of the sustain pattern neurons was lower than those of the other two types. Under noise stimulation, compared with A1 layer six, TRN neurons showed unstable auditory response (P < 0.001), higher spontaneous firing rate (P < 0.001), and longer response latency (P < 0.001). Under tone stimulation, TRN's response continuity was poor, and the frequency tuning was greatly different from that of A1 layer six (P < 0.001), but their sensitivity to tone was similar (P > 0.05), and TRN's tone response threshold was much higher than that of A1 layer six (P < 0.001). The above results demonstrate that TRN mainly undertakes the task of information transmission in the auditory system. The noise response of TRN is more extensive than the tone response. Generally, TRN prefers high-intensity acoustic stimulation.

Hiperacusia en trastornos del espectro autista: una revisión de la literatura / Hyperacusis in autism spectrum disorders: a review of the literature

Resumen La hiperacusia se define como la intolerancia a ciertos sonidos cotidianos que causa angustia y discapacidad significativas en las actividades sociales, ocupacionales, recreativas y otras actividades cotidianas. Los sonidos pueden percibirse como incómodamente fuertes, desagradables, atemorizantes o dolorosos. Se encuentra presente en aproximadamente un 3% población general, y aumenta significativamente en trastornos del espectro autista (TEA), alcanzando entre un 15% a 40%. Los mecanismos fisiopatológicos no son del todo claros, pero se ha propuesto, una alteración en el funcionamiento de mecanismos reflejos y de regulación, tanto a nivel de la vía auditiva periférica, como central, incluyendo estructuras no relacionadas directamente con la vía auditiva. El siguiente texto tiene como objetivo analizar la relación entre hiperacusia y TEA, enfatizando en la frecuencia en que se presentan como comorbilidades, en los posibles mecanismos fisiopatológicos, y en actualizaciones en el abordaje diagnóstico y terapéutico. Se realiza una revisión bibliográfica cualitativa en Pubmed con artículos entre los años 2008-2020 utilizando los términos: "hyperacusis autism", "sistema olivococlear", arrojando 39 artículos, de los cuales se seleccionaron en base a la temática de cada uno, evaluada por los autores. A pesar de una significativa relación entre hiperacusia y TEA, los mecanismos fisiopatológicos de ambas patologías siguen siendo un misterio. Existen estudios que sugieren pruebas de screening no invasivas que relacionan ambas patologías, pero debido a los sesgos de selección, todavía no son factibles de usar en forma universal. El abordaje terapéutico ha sido poco explorado, y no se dispone de fármacos que hayan demostrado su efectividad, por el contrario, algunos de ellos empeoran la sintomatología. Se recomienda al tratante, seguir un camino largo, en conjunto con el paciente, donde las terapias no farmacológicas como la terapia cognitivo conductual han mostrado tener buenos resultados.

Abstract Hyperacusis is defined as intolerance to certain sounds that causes significant distress and disability in social, occupational, recreational and other activities. Sounds can be perceived as uncomfortably loud, unpleasant, frightening, or painful. It is present in approximately 3% of the general population, and increases significantly in autism spectrum disorders (ASD), between 15% and 40%. The pathophysiological mechanisms are not entirely clear, but an alteration in the functioning of reflex and regulatory mechanisms has been proposed, both at the peripheral and central auditory pathways, including structures not directly related to the auditory pathway. The therapeutic approach has been little explored as there are no drugs that have demonstrated their effectiveness, on the contrary, some of them worsen the symptoms. The practitioner is recommended to follow a long path, in conjunction with the patient, where non-pharmacological therapies such as cognitive behavioral therapy have been shown to have good results. The following text shows a review of the literature with articles referring to the subject between the years 2008-2019.

Efeito inibitório da via eferente auditiva no transtorno de processamento auditivo central / Auditory efferent inhibitory effect in central auditory processing disorder

RESUMO Objetivo verificar e comparar a ocorrência e magnitude do efeito inibitório da via auditiva eferente em crianças e adolescentes com processamento auditivo normal e alterado, identificando um valor de corte para uso na prática clínica. Métodos estudo prospectivo, com amostra composta por 30 crianças de 7 a 14 anos, sendo 15 com avaliação de processamento auditivo normal (grupo controle) e 15 com processamento auditivo alterado (grupo estudo). Ambos os grupos foram submetidos à anamnese e avaliados por meio dos testes de emissões otoacústicas evocadas por estímulos transientes na ausência e presença de ruído contralateral, avaliação audiológica básica e de processamento auditivo. Resultados houve menor ocorrência do efeito inibitório da via eferente no grupo estudo (p-valor=0,038). Os valores médios obtidos no grupo controle foram 0,71 na orelha direita e 0,87 na orelha esquerda e no grupo estudo, 0,55 na orelha direita e 0,41 na orelha esquerda. Os grupos controle e estudo diferiram de modo significativo na orelha esquerda. Conclusão houve redução do efeito inibitório da via eferente em crianças e adolescentes com transtorno de processamento auditivo, sugerindo alteração funcional do sistema eferente olivococlear medial. O valor que separou as crianças com e sem alteração do sistema eferente foi de 0,55 dB na prática clínica, com 70% de sensibilidade e 66,7% de especificidade.

ABSTRACT Purpose Verify and compare the occurrence and magnitude of the inhibitory effect of the efferent auditory pathway in children and adolescents with normal and auditory processing disorder, identifying a cutoff value to use in clinical settings. Methods A prospective study, with a total sample of 30 children aged 7 to 14 years, half with normal auditory processing assessment (Control Group) and the other half with auditory processing disorder (Study Group). Both groups were submitted to anamnesis and evaluated using the otoacoustic emissions tests evoked by transient stimuli in the absence and presence of contralateral noise, basic audiological evaluation and auditory processing. Results The study group presented a lower occurrence of the inhibitory effect of the efferent pathway when compared to the control group (p value=0.038). The mean values ​​obtained for the control group were 0.71 in the right ear and 0.87 in the left ear and for the study group, 0.55 in the right ear and 0.41 in the left ear. The two groups showed a statistically significant difference for the left ear. Conclusion There was a reduction in the inhibitory effect of the efferent pathway in children and adolescents with auditory processing disorder, suggesting a functional change in the medial olivocochlear efferent system. In this study, the cutoff value of 0.55 dB separated children with and without alteration of the efferent system with 70% sensitivity and 66.7% specificity.

Plasticidade neuronal da via auditiva em crianças com transtorno dos sons da fala: estudo dos Potenciais Evocados Auditivos de Longa Latência / Neuronal plasticity of the auditory pathway in children with speech sound disorder: a study of Long-Latency Auditory Evoked Potentials

Resumo Objetivo Avaliar os achados dos Potenciais Evocados Auditivos de Longa Latência (PEALL) em crianças com Transtorno dos Sons na Fala (TSF) após terapia fonoaudiológica. Método Estudo clínico longitudinal e prospectivo em um grupo de 14 crianças com TSF, de cinco a sete anos de idade, de ambos os sexos. Foram aplicadas as provas de Nomeação de Figuras e Imitação de palavras, para as quais foi calculado o índice de gravidade Porcentagem de Consoantes Corretas. Foram registrados os PEALL com estímulo de fala e foram analisados os valores de latência e amplitude dos componentes P1, N1, P2, N2 e P3. Cada criança foi avaliada em dois diferentes momentos: avaliação inicial e após 12 sessões de terapia fonoaudiológica. Resultados Os resultados mostraram que após terapia fonoaudiológica, o valor do índice de gravidade Porcentagem de Consoantes Corretas aumentou e um maior número de componentes foi observado nos registros dos PEALL nas crianças com TSF. Também foi observado um aumento estatisticamente significativo na amplitude do componente P3, demostrando que modificações anatomofisiológicas ocorreram no sistema nervoso auditivo central após intervenção, proporcionando melhora nos resultados dos PEALL. Conclusão Após terapia fonoaudiológica, foi observada melhora no desempenho fonológico das crianças, aumento no número de componentes presentes nos PEALL, bem como aumento na amplitude do componente P3, demonstrando que ocorreu plasticidade na via auditiva após um curto período de intervenção fonoaudiológica.

Abstract Purpose To analyze the results of Long-latency Auditory Evoked Potentials (LLAEP) in children with Speech Sounds Disorder (SSD) after speech therapy. Methods Longitudinal and prospective clinical study at 14 children with SSD, with ages ranging from five to seven years, of both genders. Were applied Picture Naming task and Imitation task, and from these tasks it was calculated the Percentage of Consonants Correct index. For an analysis of the LLAEP with speech stimulus and recorded the latency and amplitude values ​​of P1, N1, P2, N2 and P3 components. Each child was evaluated in two different moments: initial evaluation and after 12 sessions of speech therapy. Results It was observed that after twelve sessions of speech therapy the value of Percentage of Consonants Correct index increased, and a greater number of components were observed in the LLAEP records of children with SSD, as well as a statistically significant increase in the amplitude of the P3 component, demonstrating that anatomical and physiological changes occurred in the central auditory nervous system after intervention, resulting in improved of the LLAEP results. Conclusion After speech therapy, improvement in the children's phonology was observed, and there was an increase in the number of components present in the LLAEP, as well as an increase in the amplitude of the P3 component, demonstrating that plasticity occurred in the auditory pathway during these three months of therapeutic intervention.

Hipoacusia unilateral: bases neurobiológicas de la ambliaudia / Unilateral hearing loss: neurobiological basis of amblyaudia

Resumen La hipoacusia unilateral es una alteración prevalente e importante en la población infantil que puede llevar a un deterioro del procesamiento auditivo. Cualquier patología que cause hipoacusia asimétrica (conductiva o sensorioneural) durante ventanas críticas del desarrollo cerebral, puede dar lugar a déficits del procesamiento auditivo que podrían persistir incluso después de la rehabilitación audiológica. Este proceso fisiopatológico se ha denominado "ambliaudia" y los niños que la presentan tienen un mayor riesgo de sufrir retraso en el desarrollo del lenguaje, así como de padecer dificultades académicas, sociales y cognitivas. Por esto, la ambliaudia se presenta como un desafío en audiología, siendo necesario comprender los mecanismos neurobiológicos que la subyacen. Entender de mejor manera cuáles son las consecuencias que tiene la pérdida auditiva asimétrica sobre el desarrollo del sistema nervioso podría ser clave para guiar de mejor forma las intervenciones terapéuticas. En este artículo se revisan trabajos en humanos y en modelos animales que describen las consecuencias neurobiológicas de la deprivación auditiva unilateral durante el desarrollo del sistema nervioso y su posible aplicación a la práctica clínica.

Abstract Unilateral hearing loss is a prevalent and important disorder in children that can lead to an impairment of auditory processing. Any pathology that causes asymmetric (conductive or sensorineural) hearing loss during critical brain development windows can lead to hearing deficits that may persist even after audiological rehabilitation. This pathophysiological process has been referred to as amblyaudia, and children are at greater risk of experiencing language developmental delays as well as academic, social and cognitive impairments. For this reason, amblyaudia presents itself as a challenge in audiology, and it has become necessary to understand its neurobiological mechanisms. A better understanding of the consequences of asymmetric hearing loss on the development of the nervous system may be key to better guiding therapeutic interventions. This article reviews studies performed in humans and animal models that describe the neurobiological consequences of unilateral hearing deprivation during the development of the nervous system and its possible applications to clinical practice.

Speech-in-noise perception ability can be related to auditory efferent pathway function: a comparative study in reading impaired and normal reading children / Capacidade de percepção da fala no ruído pode estar relacionada à função da via auditiva eferente: estudo comparativo de crianças com dificuldade de leitura e com leitura normal

Abstract Introduction: Deficient auditory processing can cause problems with speech perception and affect the development and evolution of reading skills. The efferent auditory pathway has an important role in normal auditory system functions like speech-in-noise perception, but there is still no general agreement on this. Objective: To study the performance of the efferent auditory system in a group of children with reading impairment in comparison with normal reading and evaluation of its relationship with speech-in-noise perception. Methods: A total of 53 children between the ages of 8-12 years were selected for the study of which 27 were with reading impairment and 26 were normal reading children. Transient evoked otoacoustic emissions suppression and auditory recognition of words-in-noise test were performed for all the children. Results: The average amplitude of transient evoked otoacoustic emissions suppression showed a significant difference between the two groups in the right (p = 0.004) and in the left ear (p = 0.028). Assessment of the relationship between transient evoked otoacoustic emissions suppression and monaural auditory recognition of words-in-noise scores showed a significant moderate negative relationship only in the right ear (p = 0.034, r = −0.41) of the normal reading children. Binaural auditory recognition of words-in-noise scores were significantly correlated with the amplitude of transient evoked otoacoustic emissions suppression in the right ear (p < 0.001, r = −0.75) and in the left ear (p < 0.001, r = −0.64) of normal reading children. In the reading impaired group, ?a weaker correlation was observed between binaural auditory recognition of words-in-noise scores and transient evoked otoacoustic emissions suppression in the right (p = 0.003, r = −0.55) and in the left ear (p = 0.012, r = −0.47). Conclusions: Transient evoked otoacoustic emissions suppression pattern in the reading impaired group was different compared with normal reading children, and this difference could be related to efferent system performance. Words-in-noise scores in children with impaired reading were lower than in normal reading children. In addition, a relationship was found between transient evoked otoacoustic emissions suppression and words-in-noise scores in both normal and impaired reading children.

Resumo Introdução: O processamento auditivo deficiente pode causar problemas na percepção da fala e afetar o desenvolvimento e a evolução das habilidades de leitura. A via auditiva eferente tem um papel importante nas funções do sistema auditivo normal, como a percepção da fala no ruído, mas ainda não há um consenso sobre isso. Objetivo: Estudar o desempenho do sistema auditivo eferente em um grupo de crianças com dificuldade de leitura em comparação às com leitura normal e avaliação de sua relação com a percepção da fala no ruído. Método: Foram selecionadas para o estudo 53 crianças entre oito e 12 anos, das quais 27 tinham dificuldade de leitura e 26 apresentavam leitura normal. A avaliação por emissões otoacústicas evocadas transientes e o teste auditory recognition of words-in-noise foram feitos em todas as crianças. Resultados: A amplitude média da supressão das emissões otoacústicas evocadas transientes mostrou diferença significante entre os dois grupos na orelha direita (p = 0,004) e esquerda (p = 0,028). A avaliação da relação entre a supressão das emissões otoacústicas evocadas transientes e os escores monoaurais do teste auditory recognition of words-in-noise mostrou uma relação negativa moderadamente significante apenas na orelha direita (p = 0,034, r = -0,41) das crianças com leitura normal. Os escores binaurais do auditory recognition of words-in-noise foram significantemente correlacionados com a amplitude de supressão das emissões otoacústicas evocadas transientes na orelha direita (p < 0,001, r = -0,75) e na orelha esquerda (p < 0,001, r = -0,64) das crianças com leitura normal. No grupo com dificuldade de leitura, uma correlação mais fraca foi observada entre os escores binaurais do auditory recognition of words-in-noise e supressão das emissões otoacústicas evocadas transientes, na orelha direita (p = 0,003, r = -0,55) e na esquerda (p = 0,012, r = -0,47). Conclusões: O padrão de supressão das emissões otoacústicas evocadas transientes no grupo com dificuldade de leitura foi diferente em comparação com as crianças com leitura normal e essa diferença pode estar relacionada ao desempenho do sistema eferente. Os escores de palavras no ruído em crianças com dificuldade de leitura foram menores do que nas crianças com leitura normal. Além disso, foi encontrada uma relação entre a supressão das emissões otoacústicas evocadas transientes e os escores de palavras no ruído tanto em crianças com leitura normal quanto nas com dificuldade de leitura.

Brainstem auditory pathway of children with acute lymphoid leukemia on chemotherapy with methotrexate / Via auditiva em tronco encefálico de crianças com leucemia linfoide aguda em quimioterapia com metotrexato

Abstract Objective: Investigate the auditory pathway in the brainstem of children with acute lymphoblastic leukemia submitted to chemotherapy (by intravenous or intrathecal infusion). Methods: Fourteen children aged between 2 and 12 years with diagnosis of acute lymphoid leukemia were evaluated. The following procedures were used: meatoscopy, acoustic immitance measurements, tonal audiometry, vocal audiometry, transient otoacoustic emissions, and auditory brainstem response. Results: From the 14 children with normal auditory thresholds, 35.71% showed an alteration in auditory brainstem response, with a predominance of hearing impairment in the lower brainstem. It was found that 80% of the children with alteration had used intrathecal methotrexate less than 30 days and that 40% had the highest cumulative intravenous methotrexate doses. Conclusion: Children with acute lymphoblastic leukemia submitted to chemotherapy, present auditory pathway impairment in the brainstem, with a predominance of a low brainstem.

Resumo Objetivo: Investigar a via auditiva em tronco encefálico de crianças com leucemia linfoide aguda submetidas à quimioterapia (por infusão intravenosa ou por via intratecal). Métodos: Foram avaliadas 14 crianças com idade entre 2 e 12 anos, com diagnóstico de leucemia linfoide aguda. Foram utilizados os seguintes procedimentos: meatoscopia, medidas de imitância acústica, audiometria tonal, audiometria vocal, emissões otoacústicas transientes e potencial evocado auditivo de tronco encefálico. Resultados: Das 14 crianças com limiares auditivos normais, 35,71% demonstraram alteração no Potencial Evocado Auditivo de Tronco Encefálico, com predomínio de comprometimento de via auditiva em tronco encefálico baixo. Verificou-se que 80% das crianças com alteração haviam feito uso do metotrexato via intratecal a menos de 30 dias e que 40% tinham as maiores doses acumulativas de metotrexato por via endovenosa. Conclusão: Crianças com leucemia linfoide aguda submetidas à quimioterapia apresentam comprometimento na via auditiva em tronco encefálico, com predomínio em tronco encefálico baixo.

Sequential bilateral cochlear implant: results in children and adolescents / Implante coclear bilateral sequencial: resultados em crianças e adolescentes

Abstract Introduction: The use of the bilateral cochlear implants can promote the symmetrical development of the central auditory pathways, thus benefiting the development of auditory abilities and improving sound localization and the ability of auditory speech perception in situations of competitive noise. Objective: To evaluate the ability of speech perception in children and adolescents using sequential bilateral cochlear implants, considering the association of these variables: age at surgery, time of device use and interval between surgeries. Methods: A total of 14 individuals between 10 and 16 years of age, who demonstrated surgical indication for the use of sequential bilateral cochlear implants as intervention in the auditory habilitation process, were assessed. The speech perception ability was assessed through sentence lists constructed in the Portuguese language, presented in two situations: in silence, with fixed intensity of 60 dB SPL, and in competitive noise, with a signal-to-noise ratio of +15 dB. The evaluation was performed under the following conditions: unilateral with the first activated cochlear implant, unilateral with the second activated cochlear implant and bilateral with both devices activated. Results: The results of the speech perception tests showed better performance in both silence and in noise for the bilateral cochlear implant condition when compared to the 1st cochlear implant and the 2nd cochlear implant alone. A worse result of speech perception was found using the 2nd cochlear implant alone. No statistically significant correlation was found between age at the surgical procedure, interval between surgeries and the time of use of the 2nd cochlear implant, and the auditory speech perception performance for all assessed conditions. The use of a hearing aid prior to the 2nd cochlear implant resulted in benefits for auditory speech perception with the 2nd cochlear implant, both in silence and in noise. Conclusion: The bilateral cochlear implant provided better speech perception in silence and in noise situations when compared to the unilateral cochlear implant, regardless of the interval between surgeries, age at the surgical procedure and the time of use of the 2nd cochlear implant. Speech perception with the 1st cochlear implant was significantly better than with the 2nd cochlear implant, both in silence and in noise. The use of the hearing aid prior to the 2nd cochlear implant influenced speech perception performance with the 2nd cochlear implant, both in silence and in noise.

Resumo Introdução: A utilização do implante coclear bilateral pode promover o desenvolvimento das vias auditivas centrais de maneira simétrica, beneficiando, assim, o desenvolvimento das habilidades auditivas e melhorando a localização sonora e a habilidade de percepção auditiva da fala em situações de ruído competitivo. Objetivo: Avaliar a habilidade de reconhecimento de fala em crianças e adolescentes usuários do implante coclear bilateral sequencial, considerando a relação das variáveis: idade cirúrgica, tempo de uso do dispositivo e intervalo entre as cirurgias. Método: Foram avaliados 14 indivíduos entre 10 e 16 anos, que receberam indicação cirúrgica para implante coclear bilateral sequencial como forma de intervenção no processo de habilitação auditiva. A habilidade de reconhecimento de fala foi avaliada por meio de listas de sentenças construídas na língua portuguesa, apresentadas em duas situações: no silêncio, com intensidade fixa de 60 dB NPS, e no ruído competitivo, com a relação sinal/ruído de + 15 dB. A avaliação foi feita nas seguintes condições: unilateral com o 1° implante coclear ativado, unilateral com o 2° implante coclear ativado e bilateral com ambos os dispositivos ativados. Resultado: Os resultados dos testes de reconhecimento de fala demonstraram melhor desempenho tanto no silêncio quanto no ruído para a condição implante coclear bilateral, quando comparado ao 1° implante coclear e 2° implante coclear isoladamente. Um pior resultado de reconhecimento de fala foi encontrado com o uso do 2° implante coclear isoladamente. Não foi encontrada correlação estatisticamente significante entre idade cirúrgica, intervalo entre as cirurgias e tempo de uso do 2° implante coclear e o desempenho de percepção auditiva da fala para todas as condições avaliadas. O uso do aparelho de amplificação sonora individual anterior ao 2° implante coclear beneficiou os resultados de percepção auditiva da fala com o 2° implante coclear, tanto no silêncio quanto no ruído. Conclusão: O implante coclear bilateral proporcionou melhor reconhecimento de fala em situações de silêncio e de ruído, quando comparado com o implante coclear unilateral, independentemente do intervalo entre as cirurgias, da idade cirúrgica e do tempo de uso do 2° implante coclear. O reconhecimento de fala com o 1° implante coclear foi significativamente melhor do que com o 2° implante coclear, tanto no silêncio quanto no ruído. O uso do aparelho de amplificação sonora individual anterior ao 2° implante coclear influenciou o desempenho de reconhecimento de fala com o 2° implante coclear, tanto no silêncio quanto no ruído.

Changes in the Laterality of Functional Connectivity Associated with Tinnitus: Resting-State fMRI Study

PURPOSE: One of the suggested potential mechanisms of tinnitus is an alteration in perception in the neural auditory pathway. The aim of this study was to investigate the difference in laterality in functional connectivity between tinnitus patients and healthy controls using resting state functional MRI (rs-fMRI). MATERIALS AND METHODS: Thirty-eight chronic tinnitus subjects and 45 age-matched healthy controls were enrolled in this study. Connectivity was investigated using independent component analysis, and the laterality index map was calculated based on auditory (AN) and dorsal attention (DAN), default mode (DMN), sensorimotor, salience (SalN), and visual networks (VNs). The laterality index (LI) of tinnitus subjects was compared with that of normal controls using region-of-interest (ROI) and voxel-based methods and a two-sample unpaired t-test. Pearson correlation was conducted to assess the associations between the LI in each network and clinical variables. RESULTS: The AN and VN showed significant differences in LI between the two groups in ROI analysis (P < 0.05), and the tinnitus group had clusters with significantly decreased laterality of AN, SalN, and VN in voxel-based comparisons. The AN was positively correlated with tinnitus distress (tinnitus handicap inventory), and the SalN was negatively correlated with symptom duration (P < 0.05). CONCLUSION: The results of this study suggest that various functional networks related to psychological distress can be modified by tinnitus, and that this interrelation can present differently on the right and left sides, according to the dominance of the network.

Efeito da levodopa na mecânica coclear e no sistema auditivo eferente de indivíduos com doença de Parkinson / Effect of levodopa on cochlear mechanics and efferent auditory system of Parkinson's disease individuals

RESUMO Objetivo Analisar o efeito da levodopa na dinâmica coclear, bem como na via eferente olivococlear medial de indivíduos com doença de Parkinson idiopática (DP). Método Indivíduos com e sem DP, acompanhados em um hospital universitário, realizaram a pesquisa das emissões otoacústicas por produto de distorção (EOAPD) e do efeito inibitório das EOAPD (EIEOA) na presença de ruído contralateral. Foram estabelecidas as medidas de correlação entre os resultados das EOAPD e do EIEOA com estágio Hoehn&Yahr (H&Y), dose diária de levodopa e tempo de diagnóstico da DP. Além disso, as medidas eletroacústicas foram comparadas entre os indivíduos sem DP e com DP, estratificados de acordo com a dose de levodopa administrada diariamente. Resultados Foi identificada correlação fraca e negativa entre a amplitude das EOAPD com a dose diária de levodopa e correlações positivas, de força moderada e fraca, entre o EIEOA com a dose diária de levodopa e o tempo de diagnóstico da DP, respectivamente. A amplitude das EOAPD foi maior nos indivíduos com DP em uso de levodopa ≤ 600 miligramas quando comparada à de indivíduos sem DP e com DP, em uso de dose superior. Já o EIEOA foi menor nos indivíduos em uso de doses ≤ 600 miligramas, quando comparado aos demais grupos. Conclusão Doses diárias de levodopa iguais ou inferiores a 600 mg/dia aumentam as respostas mecanotransdutoras cocleares nas frequências de 2 e 3 kHz, enquanto que a ação dos sistemas eferentes olivococleares é reduzida nesta região.

ABSTRACT Purpose To evaluate the effect of levodopa on cochlear dynamics and on the medial olivocochlear efferent pathway of idiopathic Parkinson's disease (PD) individuals. Methods Individuals with and without PD, followed at a University Hospital, were submitted to Distortion Product Otoacoustic Emissions (DPOAE) and DPOAE Inhibitory Effect (OAEIE) in the presence of contralateral noise. Correlation measures between DPOAE and OAEIE results with Hoehn&Yahr (H&Y) stage, daily dose of levodopa and PD diagnosis period were established. Furthermore, electroacoustic measures were compared between individuals without and those with PD, stratified by dose of levodopa daily administered. Results Weak negative correlation between DPOAE amplitude and daily dose of levodopa was found, as well positive correlations between EIEOA with daily dose of levodopa and time of PD diagnosis, respectively. Higher DPOAE amplitude was found in individuals with PD using daily doses of levodopa ≤ 600 milligrams when compared to individuals without PD and those with PD using higher doses. EIEOA was lower in individuals using doses ≤ 600 milligrams, when compared to the other groups. Conclusion Daily doses of levodopa up to 600 mg / day increase the cochlear mechanical-transducer responses in 2 and 3 kHz frequencies, while the action of olivocochlear efferent systems is reduced in this region.

Hyperbilirubinemia and Follow-up Auditory Brainstem Responses in Preterm Infants

OBJECTIVES.: Neonatal hyperbilirubinemia is considered one of the most common causative factors of hearing loss. Preterm infants are more vulnerable to neuronal damage caused by hyperbilirubinemia. This study aimed to evaluate the effect of hyperbilirubinemia on hearing threshold and auditory pathway in preterm infants by serial auditory brainstem response (ABR). In addition, we evaluate the usefulness of the unconjugated bilirubin (UCB) level compared with total serum bilirubin (TSB) on bilirubin-induced hearing loss. METHODS.: This study was conducted on 70 preterm infants with hyperbilirubinemia who failed universal newborn hearing screening by automated ABR. The diagnostic ABR was performed within 3 months after birth. Follow-up ABR was conducted in patients with abnormal results (30 cases). TSB and UCB concentration were compared according to hearing threshold by ABR. RESULTS.: The initial and maximal measured UCB concentration for the preterm infants of diagnostic ABR ≥40 dB nHL group (n=30) were statistically higher compared with ABR ≤35 dB nHL group (n=40) (P=0.031 and P=0.003, respectively). In follow-up ABR examination, 13 of the ABR ≥40 dB nHL group showed complete recovery, but 17 had no change or worsened. There was no difference in bilirubin level between the recovery group and non-recovery group. CONCLUSION.: UCB is a better predictor of bilirubin-induced hearing loss than TSB in preterm infants as evaluated by serial ABR. Serial ABR testing can be a useful, noninvasive methods to evaluate early reversible bilirubin-induced hearing loss in preterm infants.

Auditory Deficits in Patients With Mild and Moderate Obstructive Sleep Apnea Syndrome: A Speech Syllable Evoked Auditory Brainstem Response Study

OBJECTIVES: The energy consumption process of cochlea and neural signal transduction along the auditory pathway are highly dependent on blood oxygen supply. At present, it is under debate on whether the obstructive sleep apnea syndrome (OSAS) would affect the auditory function since the patients suffer from low oxygen saturation. Moreover, it is difficult to detect the functional state of auditory in less severe stage of OSAS. Recently, speech-evoked auditory brainstem response (speech-ABR) has been reported to be a new electrophysiological tool in characterizing the auditory dysfunction. The aim of the present study is to evaluate the auditory processes in adult patients with mild and moderate OSAS by speech-ABR. METHODS: An experimental group of 31 patients with mild to moderate OSAS, and a control group without OSAS diagnosed by apnea hypopnea index in polysomnogram were recruited. All participants underwent otologic examinations and tests of pure-tone audiogram, distortion product otoacoustic emissions, click-evoked auditory brainstem response (click-ABR) and speech-ABR, respectively. RESULTS: The results of pure-tone audiogram, distortion product otoacoustic emissions, and click-ABR in OSAS group showed no significant differences compared with the control group (P>0.05). Speech-ABRs for OSAS participants and controls showed similar morphological waveforms and typical peak structures. There were significant group differences for the onset and offset transient peaks (P < 0.05), where OSAS group had longer latencies for peak V (6.69± 0.33 ms vs. 6.39±0.23 ms), peak C (13.48±0.30 ms vs. 13.31±0.23 ms), and peak O (48.27±0.39 ms vs. 47.60± 0.40 ms) compared to the control group. The latency of these peaks showed significant correlations with apnea hypopnea index for peak V (r=0.37, P=0.040), peak C (r=0.36, P=0.045), as well as peak O (r=0.55, P=0.001). CONCLUSION: These findings indicate that some auditory dysfunctions may be present in patients with mild and moderate OSAS, and the damages were aggravated with the severity of OSAS, which suggests that speech-ABR may be a potential biomarker in the diagnosis and evaluation at early stage of OSAS.

The importance of central auditory evaluation in Friedreich's ataxia / A importância da avaliação auditiva central na ataxia de Friedreich

ABSTRACT Objective To assess central auditory function in Friedreich's ataxia. Methods A cross-sectional, retrospective study was carried out. Thirty patients underwent the anamnesis, otorhinolaryngology examination, pure tone audiometry, acoustic immittance measures and brainstem auditory evoked potential (BAEP) assessments. Results The observed alterations were: 43.3% in the pure tone audiometry, bilateral in 36.7%; 56.6% in the BAEP test, bilateral in 50%; and 46.6% in the acoustic immittance test. There was a significant difference (p < 0.05) in the comparison between the tests performed. Conclusion In the audiological screening, there was a prevalence of the descending audiometric configuration at the frequency of 4kHz, and absence of the acoustic reflex at the same frequency. In the BAEP test, there was a prevalence of an increase of the latencies in waves I, III and V, and in the intervals of interpeaks I-III, I-V and III-V. In 13.3% of the patients, wave V was absent, and all waves were absent in 3.3% of patients.

RESUMO Objetivo Avaliar a função auditiva central na ataxia de Friedreich (AFRD). Métodos Foi realizado um estudo retrospectivo de corte transversal. 30 pacientes realizaram anamnese, avaliações otorrinolaringológica, audiológica, imitanciométrica e do potencial evocado auditivo de tronco encefálico (PEATE). Resultados As alterações observadas foram: 43,3% no exame audiométrico sendo 36,7% dos casos, bilateralmente; 56,6% na avaliação do PEATE com 50% dos casos, bilateralmente e 46,6% no exame imitanciométrico. Houve diferença significativa (p < 0,05) na comparação entre os exames realizados. Conclusão No exame audiológico, ocorreu uma preponderância maior da configuração audiométrica descendente a partir da freqüência de 4kHz e ausência do reflexo acústico na mesma frequência. No exame do PEATE, houve prevalência do aumento das latências nas ondas I, III e V, e nos intervalos dos interpicos I-III, I-V e III-V. Em 13,3% dos casos, a onda V estava ausente, e em 3,3% dos casos, todas as ondas estavam ausentes.

Alterações auditivas em recém-nascidos e lactentes com mielomeningocele / Hearing impairment in newborns and infants with myelomeningocele

RESUMO Objetivo Verificar a ocorrência de alterações auditivas em recém-nascidos e lactentes com mielomeningocele e/ou Síndrome de Arnold Chiari tipo II. Métodos Foram incluídos na amostra 160 neonatos atendidos em unidade de terapia intensiva neonatal, distribuídos em três grupos: Grupo Estudo 1, formado por 42 neonatos com Síndrome de Arnold Chiari tipo II; Grupo Estudo 2, constituído por 38 neonatos com mielomeningocele e Grupo Controle, com 80 recém-nascidos sem síndromes, malformações e/ou riscos para alteração auditiva. Todos os pacientes realizaram a triagem auditiva neonatal com emissões otoacústicas evocadas por estímulo transiente e foram submetidos à pesquisa do potencial evocado auditivo de tronco encefálico com estímulo clique. Quando houve falha nas emissões, a pesquisa dos limiares eletrofisiológicos foi realizada mediante potencial evocado auditivo de tronco encefálico com tone burst . A análise estatística foi feita por meio de testes paramétricos e os dados encontrados foram descritos nos resultados, considerando o nível de significância p<0,05. Resultados Houve maior ocorrência de perda coclear, alteração central e neuropatia auditiva nos grupos estudados. No que se refere aos valores médios das latências absolutas e dos intervalos interpicos, nos três grupos, por orelha, houve aumento das latências absolutas das ondas III e V e dos intervalos interpicos III-V e I-V , no grupo de lactentes com Síndrome de Arnold Chiari tipo II. Conclusão Recém-nascidos e lactentes com Síndrome de Arnold Chiari tipo II e mielomeningocele apresentaram maior ocorrência de perda coclear, espectro da neuropatia auditiva e alterações centrais.

ABSTRACT Purpose To characterize Auditory and oral language performance in children under 2 years of age with Hearing and Language Development Scale (EDAL-1) and to compare the results to those of hearing children up to two years of age. Methods This is an experimental study of descriptive nature. A total of 141 children were divided into two groups: control group with 92 normal hearing, and the experimental group with 49 deaf children followed audiologically during the first two years after implantation. Normal hearing children underwent auditory assessment and parents responded to EDAL-1. The children implanted, every three months, underwent otorhinolaryngological and speech-language evaluation, and the parents answered EDAL-1. Results In both groups we observed upward responses, with improvement as chronological and auditory age increases. Results obtained in the study group are statistically worse than in the control group, but with a tendency to grow. EDAL-1 was easy to apply and allowed to monitor the performance of the implanted children. Conclusion Oral and auditory performance in deaf children with cochlear implants was characterized by EDAL-1, and it was shown to be growing as the time of auditory stimulation increased, a fact also seen in hearing children. Despite this, the results of the hearing children were better than those of the deaf children implanted.

Ongoing maturation in the time-compressed speech test

OBJECTIVES: To verify the neuromaturational influence in the ability of auditory closure, that is, to verify the performance of children and young adults in the ability of auditory closure, through the time compressed speech test (TCS). METHODS: Thirty children (8 to 10 years old) and 30 young adults (16 to 24 years old) with normal hearing without complaints (neurological, cognitive, auditory processing) who performed TFC (monosyllables and disyllables) with a compression ratio of 60% in both ears. Statistical analysis was performed using analysis of variance (ANOVA) and ANOVA with repeated measures with a significance level of 0.05. The minimum statistical power was 80%. RESULTS: In the comparison between ears, there was no significant difference between groups for the monosyllables. For disyllables, the second ear tested was better in children, and the right ear was better than the left ear for young adults. In the comparison between modalities (monosyllables and disyllables), children did not show significant differences. The performance of the young adults was better in the disyllables in both ears. Comparing the age groups, the young adults were better than the children for both modalities and ears. CONCLUSION: The study has demonstrated the influence and impact of age (maturational factor) on TCS test performance, showing the importance of establishing normality patterns for various age groups to provide a standardized tool for evaluation of auditory closure ability.

Monitoring auditory cortical plasticity in hearing aid users with long latency auditory evoked potentials: a longitudinal study

OBJECTIVE: The objective of this study was to compare long-latency auditory evoked potentials before and after hearing aid fittings in children with sensorineural hearing loss compared with age-matched children with normal hearing. METHODS: Thirty-two subjects of both genders aged 7 to 12 years participated in this study and were divided into two groups as follows: 14 children with normal hearing were assigned to the control group (mean age 9 years and 8 months), and 18 children with mild to moderate symmetrical bilateral sensorineural hearing loss were assigned to the study group (mean age 9 years and 2 months). The children underwent tympanometry, pure tone and speech audiometry and long-latency auditory evoked potential testing with speech and tone burst stimuli. The groups were assessed at three time points. RESULTS: The study group had a lower percentage of positive responses, lower P1-N1 and P2-N2 amplitudes (speech and tone burst), and increased latencies for the P1 and P300 components following the tone burst stimuli. They also showed improvements in long-latency auditory evoked potentials (with regard to both the amplitude and presence of responses) after hearing aid use. CONCLUSIONS: Alterations in the central auditory pathways can be identified using P1-N1 and P2-N2 amplitude components, and the presence of these components increases after a short period of auditory stimulation (hearing aid use). These findings emphasize the importance of using these amplitude components to monitor the neuroplasticity of the central auditory nervous system in hearing aid users.

Masking Level Difference em escolares: análises ambientais / Masking Level Difference in schoolchildren: environmental analysis

RESUMO Objetivo Pesquisar a habilidade auditiva de atenção seletiva na população escolar e identificar valores de referência para a faixa etária de sete a dez anos por meio do teste Masking Level Difference, além de identificar se a escolaridade dos pais, bem como a renda familiar, pode influenciar os resultados do teste. Método Participaram do estudo 31 escolares que se encaixaram nos critérios de elegibilidade da pesquisa, sendo 20 do gênero feminino e 11 do gênero masculino. Realizou-se anamnese para questionamento da renda familiar e escolaridade dos pais do escolar, inspeção visual do meato acústico externo, audiometria tonal liminar, logoaudiometria, medidas de imitância acústica, teste Dicótico de Dígitos e teste Masking Level Difference. Resultados A idade média dos indivíduos foi de 8,67 anos. Não foi observada diferença entre os gêneros e entre as idades avaliadas, no desempenho do MLD. Não houve relação entre a escolaridade dos pais e a renda mensal média com o desempenho das crianças no MLD. A média do MLD foi de 7,65 dB, com desvio padrão de 2,51 dB. Conclusão O Masking Level Difference em escolares de sete a dez anos é de 7,65 dB e independe do gênero, do nível de escolaridade dos pais ou da renda mensal média da família do escolar.

ABSTRACT Purpose To investigate the auditory ability of selective attention in the school population and to identify reference values to the age group from seven to ten years old through the Masking Level Difference Test, and to identify if the parents' schooling, as well as the family income can influence the test results. Methods Thirty-one schoolchildren who match the eligibility criteria attended the study, being 20 female and 11 male. An anamnesis was conducted to question the familiar income and the schooling of the children´s parents; we also performed visual inspection of the External Acoustic Meatus, Pure Tone Audiometry, Speech Audiometry, Acoustic Immittance Measures, Dichotic Digits Test and Masking Level Difference test. Results The mean age of the individuals was 8.67 years. There were no observed differences between genders and between the evaluated ages in the MLD performance. There was no relation between the parents' schooling and the average monthly income with the performance of the children in MLD Test. The MLD mean was 7.65 dB and standard deviation of 2.51 dB. Conclusion The Masking Level Difference in schoolchildren from seven to ten years old is 7.65 dB and is independent of the gender, parents' schooling and the average monthly income of the schoolchild.

Auditory maturation and psychological risk in the first year of life / Maturação auditiva e risco psíquico no primeiro ano de vida

ABSTRACT Purpose To assess the potential association between psychological risk and limited auditory pathway maturation. Methods In this longitudinal cohort study, 54 infants (31 non-risk and 23 at-risk) were assessed from age 1 to 12 months. All had normal hearing and underwent assessment of auditory maturation through cortical auditory evoked potentials testing. Psychological risk was assessed with the Child Development Risk Indicators (CDRIs) and PREAUT signs. A variety of statistical methods were used for analysis of results. Results Analysis of P1 and N1 latencies showed that responses were similar in the both groups. Statistically significant differences between-groups were observed only for the variables N1 latency and amplitude at 1 month. Significant maturation occurred in both groups (p<0.05). There was moderate correlation between P1 latency and Phase II CDRIs, which demonstrates that children with longer latencies at age 12 months were more likely to exhibit absence of these indicators in Phase II and, therefore, were at greater psychological risk. The Phase II CDRIs also correlated moderately with P1 and N1 latencies at 6 months and N1 latencies at 1 month; again, children with longer latency were at increased risk. Conclusion Less auditory pathway maturation correlated with presence of psychological risk. Problems in the mother-infant relationship during the first 6 months of life are detrimental not only to cognitive development, but also to hearing. A fragile relationship may reflect decreased auditory and linguistic stimulation.

RESUMO Objetivo Avaliar a associação entre risco psíquico e maturação da via auditiva. Método Neste estudo de coorte longitudinal, 54 crianças ouvintes (31 sem risco e 23 em risco psíquico) de 1 a 12 meses foram avaliadas. Todas foram submetidas à avaliação da maturação auditiva através dos Potenciais Evocados Auditivos Corticais. O risco psíquico foi avaliado com os Indicadores de Risco de Desenvolvimento Infantil (IRDI) e Sinais PREAUT. Uma variedade de métodos estatísticos foi utilizada para análise de resultados. Resultados A análise das latências de P1 e N1 mostraram respostas similares entre os grupos. Diferenças estatisticamente significantes entre os grupos foram observadas somente para as variáveis latência e amplitude de N1 no primeiro mês. A maturação auditiva foi significante nos dois grupos (p<0,05). Houve correlação moderada entre latência de P1 e a fase II dos IRDI, demonstrando que crianças com maior latência aos 12 meses apresentaram maior probabilidade de exibir a ausência desses indicadores na Fase II, estando em maior risco psíquico. A fase II dos IRDI também teve correlação moderada com as latências de P1 e N1 aos 6 meses e latências de N1 ao 1 mês; novamente, crianças com latência mais longa estavam em maior risco. Conclusão A menor maturação auditiva correlacionou-se com a presença de risco psíquico. Problemas na relação mãe-filho durante os primeiros 6 meses de vida são prejudiciais não apenas ao desenvolvimento cognitivo, mas também à audição. Um relacionamento frágil pode refletir diminuição da estimulação auditiva e linguística.

Taurine Transporter dEAAT2 is Required for Auditory Transduction in Drosophila / 神经科学通报·英文版

Drosophila dEAAT2, a member of the excitatory amino-acid transporter (EAAT) family, has been described as mediating the high-affinity transport of taurine, which is a free amino-acid abundant in both insects and mammals. However, the role of taurine and its transporter in hearing is not clear. Here, we report that dEAAT2 is required for the larval startle response to sound stimuli. dEAAT2 was found to be enriched in the distal region of chordotonal neurons where sound transduction occurs. The Ca imaging and electrophysiological results showed that disrupted dEAAT2 expression significantly reduced the response of chordotonal neurons to sound. More importantly, expressing dEAAT2 in the chordotonal neurons rescued these mutant phenotypes. Taken together, these findings indicate a critical role for Drosophila dEAAT2 in sound transduction by chordotonal neurons.

Effect of Neuronal Excitability in Hippocampal CA1 Area on Auditory Pathway in a Rat Model of Tinnitus / 中华医学杂志(英文版)

Background@#Tinnitus is a common disorder that causes significant morbidity; however, the neurophysiological mechanism is not yet fully understood. A relationship between tinnitus and limbic system has been reported. As a significant component of the limbic system, the hippocampus plays an important role in various pathological processes, such as emotional disturbance, decreased learning ability, and deterioration of memory. This study was aimed to explore the role of the hippocampus in the generation of tinnitus by electrophysiological technology.@*Methods@#A tinnitus model was established in rats through intraperitoneal injection of salicylate (SA). Subsequently, the spontaneous firing rate (SFR) of neurons in the hippocampal CA1 area was recorded with in vivo multichannel recording technology to assess changes in excitability induced by SA. To investigate the effect of excitability changes of hippocampus on the auditory pathway, the hippocampus was electrically stimulated and neural excitability in the auditory cortex (AC) was monitored.@*Results@#Totally 65 neurons in the hippocampal CA1 area were recorded, 45 from the SA group (n = 5), and 20 from the saline group (n = 5). Two hours after treatment, mean SFR of neurons in the hippocampal CA1 area had significantly increased from 3.06 ± 0.36 Hz to 9.18 ± 1.30 Hz in the SA group (t = -4.521, P 0.05). In the AC, 79.3% (157/198) of recorded neurons showed responses to electrical stimulation of the hippocampal CA1 area. Presumed pyramidal neurons were excited, while intermediate neurons were inhibited after electrical stimulation of the hippocampus.@*Conclusions@#The study shows that the hippocampus is excited in SA-induced tinnitus, and stimulation of hippocampus could modulate neuronal excitability of the AC. The hippocampus is involved in tinnitus and may also have a regulatory effect on the neural center.