Reflejo olivococlear contralateral y su relación con ansiedad y calidad de vida en pacientes con tinnitus

Resumen Introducción: La presencia de tinnitus se asocia a un incremento del nivel de ansiedad y empeoramiento de la calidad de vida, sin embargo, aún no existe claridad de si el sistema eferente auditivo podría influir en estas relaciones. Objetivo: Determinar si las amplitudes de las emisiones otoacústicas por producto de distorsión (EOAPD) y el efecto supresor del reflejo olivococlear gatillado con ruido contralateral (ROC) se asocian al grado del impacto psicoemocional y nivel de ansiedad en pacientes con tinnitus. Material y Método: Se evaluaron las amplitudes de EOAPD y magnitud del ROC para cada oído de manera independiente en una cohorte de 32 sujetos tinnitus y 26 controles, cuyos valores fueron correlacionados con State-Trait Anxiety Inventory (STAI) y Tinnitus Handicap Inventory (THI). Resultados: Los pacientes con tinnitus tuvieron una correlación significativa entre la magnitud del ROC del oído izquierdo y los puntajes en las pruebas de STAI y THI. Conclusión: Una mayor carga de ansiedad y peor calidad de vida en sujetos con tinnitus puede estar asociada con un empeoramiento del efecto supresor del ROC de la vía eferente auditiva.

Abstract Introduction: Tinnitus is associated with an increase in the degree of anxiety and with worse quality of life. However, whether there are relations between the function of the auditory efferent system and anxiety and tinnitus distress levels is not known. Aim: To determine possible associations between the distortion product otoacoustic emission (DPOAE) amplitudes and the suppressing effect of the olivo-cochlear reflex (OCR) with anxiety and psycho-emotional impact in tinnitus. Material and Method: DPOAE amplitudes and OCR strength were evaluated for each ear independently in a cohort of 32 tinnitus and 26 controls, whose values were correlated with the State-Trait Anxiety Inventory (STAI) and Tinnitus Handicap Inventory (THI). Results: A significant correlation of STAI and THI scales with the OCR strength measured in the left ear was found in subjects with tinnitus. Conclusion: A higher anxiety load and worse quality of life in subjects with tinnitus may be associated with an impaired olivocochlear reflex suppressing effect.

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.

Functional Significance of Medial Olivocochlear System Morphology in the Mouse Cochlea

OBJECTIVES: Baso-apical gradients exist in various cochlear structures including medial olivocochlear (MOC) efferent system. This study investigated the cochlear regional differentials in the function and morphology of the MOC system, and addressed the functional implications of regional MOC efferent terminals (ETs) in the mouse cochlea. METHODS: In CBA/J mice, MOC reflex (MOCR) was assessed based on the distortion product otoacoustic emission in the absence and presence of contralateral acoustic stimulation. High, middle, and low frequencies were grouped according to a mouse place-frequency map. Cochlear whole mounts were immunostained for ETs with anti-α-synuclein and examined using confocal laser scanning microscopy. The diameters of ETs and the number of ETs per outer hair cell were measured from the z-stack images of the basal, middle and apical regions, respectively. RESULTS: The middle cochlear region expressed large, clustered MOC ETs with strong MOCR, the base expressed small, less clustered ETs with strong MOCR, and the apex expressed large, but less clustered ETs with weak MOCR. CONCLUSION: The mouse cochlea demonstrated regional differentials in the function and morphology of the MOC system. Strong MOCR along with superior MOC morphology in the middle region may contribute to ‘signal detection in noise,’ the primary efferent function, in the best hearing frequencies. Strong MOCR in spite of inferior MOC morphology in the base may reflect the importance of ‘protection from noise trauma’ in the high frequencies.

Mercury Exposure in a Riverside Amazon Population, Brazil: A Study of the Ototoxicity of Methylmercury

Introduction Mercury poisoning causes hearing loss in humans and animals. Acute and long-term exposures produce irreversible peripheral and central auditory system damage, and mercury in its various forms of presentation in the environment is ototoxic. Objective We investigated the otoacoustic emissions responses in a riverside population exposed to environmental mercury by analyzing the inhibitory effect of the medial olivocochlear system (MOCS) on transient otoacoustic emissions (TEOAE). Methods The purpose of the research was to evaluate the entire community independently of variables of sex and age. All of the participants were born and lived in a riverside community. After otolaryngologic evaluation, participants were received tympanometry, evaluation of contralateral acoustic reflexes, pure tone audiometry, and recording of TEOAEs with nonlinear click stimulation. Hair samples were collect to measure mercury levels. Results There was no significant correlation between the inhibitory effect of the MOCS, age, and the level of mercury in the hair. Conclusions The pathophysiological effects of chronic exposure may be subtle and nonspecific and can have a long period of latency; therefore, it will be important to monitor the effects of mercury exposure in the central auditory system of the Amazon population over time. Longitudinal studies should be performed to determine whether the inhibitory effect of the MOCS on otoacoustic emissions can be an evaluation method and diagnostic tool in populations exposed to mercury. .

Desde la corteza auditiva a la cóclea: progresos en el sistema eferente auditivo / From auditory cortex to cochlea: progress in the auditory efferent system

El sistema eferente auditivo está constituido por el sistema olivococlear y por vías descendentes que provienen de la corteza auditiva y se dirigen a la cóclea. El sistema olivococlear se divide en una porción medial y una lateral, con neuronas que inervan a las células ciliadas externas y a fibras del nervio auditivo respectivamente. El principal neurotransmisor de las sinapsis olivococleares es acetilcolina, y tanto las células ciliadas externas como las fibras del nervio auditivo poseen receptores para esta molécula. El sistema eferente córtico-coclear se origina en la capa V y VI de la corteza auditiva y proyecta a los colículos inferiores y complejo olivar superior, donde a través del sistema olivococlear se conecta con el órgano receptor auditivo. En este artículo se revisan importantes hallazgos obtenidos en los últimos años que involucran (i) nuevos neurotransmisores y receptores del sistema eferente auditivo; (ii) vías descendentes de la corteza auditiva y su rol fisiológico sobre las respuestas cocleares y (iii) rol del sistema eferente auditivo en patologías audiológicas y neuropsiquiátricas.

The auditory efferent system is composed by the olivocochlear fibers and descending projections that originate in the auditory cortex and end in the cochlea. The olivocochlear system is divided into a medial and lateral division, with fibers directed to the outer hair cells and to the auditory nerve fibers respectively. It is known that acetylcholine is the main neurotransmitter of the olivocochlear synapses and that outer hair cells and auditory nerve fibers have receptors to this molecule. The cortico-cochlear efferent system originates in layers V and VI of the auditory cortex. These descending projections are directed to the inferior colliculus and superior olivary complex, a site in which the olivocochlear fibers emerge and connect the brain with the cochlear receptor. In this article recent discoveries obtained in the last years are reviewed: (i) new neurotransmitters and receptors of the olivocochlear system; (ii) anatomy and physiology of descending pathways from the auditory cortex to the cochlea and, (iii) clinical role of auditory efferents in audiological and neuropsychiatric pathologies.

Estudo comparativo entre o aproveitamento escolar de alunos de escola de 1º grau e teste de inibição de emissões otoacústicas transientes / Comparative study between school performance on first grade children and suppression of otoacoustic transient emission

O processamento auditivo é fundamental para a cognição e pode ocasionar deficiência no aprendizado. Os portadores de sua deficiência podem ser habilitados, melhorando o desempenho escolar. É fundamental identificá-los. Dentre os que apresentam baixo custo e facilidade operacional está o exame de emissões otoacústicas. TIPO DE ESTUDO: Clínico e experimental. OBJETIVO: Estudar a relação do aproveitamento escolar com a inibição da emissão otoacústica transiente por estímulo auditivo contralateral. Material e Métodos: Foram avaliados 39 alunos, de sete a doze anos, sendo 19 (48,7 por cento) com bom aproveitamento escolar e 20 (51,3 por cento) com aproveitamento inadequado. Os exames emissão otoacústica com inibição contralateral foram comparados aos resultados de aproveitamento escolar. RESULTADOS: A falha da supressão da otoemissão transiente por estímulo acústico contralateral foi mais encontrada no grupo de crianças com mau aproveitamento escolar. Foi estabelecido um valor de corte de 1.6 dB SPL de redução da otoemissão que caracteriza a criança como pertencente ao grupo com mau aproveitamento com sensibilidade de 65,0 por cento, especificidade de 72,2 por cento, acurácia de 68,4 por cento e valor preditivo positivo de 72,2 por cento. CONCLUSÃO: O teste da falha da inibição contralateral da emissão otoacústica por estímulo auditivo contralateral é preditivo de transtorno do aproveitamento escolar em indivíduos de seis a doze anos de idade.

School learning can be hampered if there are defects on the central auditory process. Since those with auditory deficiency can be rehabilitated, it is fundamental that we identify them. Otoacoustic emissions test has low cost and operational ease. Study design: clinical and experimental. AIM: to study the relationship between school learning and transient otoacoustic emission suppression by contralateral stimuli. MATERIAL AND METHODS: 39 individuals, from 7 to 12 years of age were evaluated, 19 (48.7 percent) with good school performance and 20 (51.3 percent) poor performers. RESULTS: A transient otoacoustic emission suppression failure for contralateral acoustic stimuli was more frequently found among children with poor school performance. We established a value of 1.6 dB SPL for emission reduction that characterized those children as belonging to the poor learning performance group: sensitivity 65 percent, specificity 72,2 percent, accuracy of 68.4 percent, positive predictive value of 72.2 percent. CONCLUSION: The contralateral emission suppression test of the right ear can be predictive of school difficulties in individuals from six to twelve years of age.

The Effect of Contralateral Acoustic Stimulation on the Latency of Distortion Product Otoacoustic Emissions / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The auditory efferent system -Medial olivocochlear bundle (MOCB)-controls the sensitivity and frequency selectivity of the cochlea and maintains the cochlea for optimal acoustic signaling. Contralateral acoustic sound stimulates the MOCB and has inhibitory effects on the sound evoked amplitude response of the cochlea. There are only a few reports on the latency response of contralateral acoustic stimulation (CAS) on distortion product otoacoustic emission (DPOAE), and it has no consistent conclusion. The purpose of this study was to evaluate whether changing the latency of DPOAE by CAS could be a stable method for monitoring the function of MOCB. SUBJECTS AND METHOD: The change in the latencies of DPOAE after CAS were monitored in 24 normal hearing ears with f2 sweep paradigm. The CAS level was divided into two groups, one was under 65 dB SPL and other was over 65 dB SPL. RESULTS: As f2 frequency changed from 1 kHz to 2 kHz, the latency of DPOAE was shortened from 11.82 +/- 1.87 ms to 7.29 +/- 0.86 ms in low stimulation level (50 dB SPL) and from 10.70 +/- 2.65 ms to 6.16 +/- 1.59 ms in high stimulation level (75 dB SPL) There were no significant shortening on the latency of DPOAE after CAS in low stimulation level group. But in higher stimulation level group (75 dB SPL), DPOAE latency changed from 10.70 +/- 2.65 ms to 10.12 +/- 1.95 ms (CAS level: 35 dB SL) and to 9.76 +/- 2.97 ms (CAS level: 50 dB SL) in 1 kHz, from 6.16 +/- 1.59 ms to 5.96 +/- 1.49 ms (CAS level: 35 dB SL) and to 5.83 +/- 1.28 ms (CAS level: 50 dB SL) in 2 kHz. CONCLUSION: Changes in the latency of DPOAE after CAS is not a stable monitoring tool for the function of MOCB.

Distribution of Calcitonin Gene-Related Peptide Immunoreactive Nerve Fibers in Rat Cochlea and Brainstem Auditory Nuclei / 대한이비인후과학회지

BACKGROUND: Calcitonin gene-related peptide(CGRP) is one of the neuronal elements of the inner ear. CGRP immunoreactive fibers are known to regulate auditory action potential and blood flow of cochlea. OBJECTIVES: This study was designed to localize the CGRP immunoreactive fibers in the cochlear tissue and auditory brainstem of normal rat. MATERIAL AND METHODS: Male Sprague-Dawley rats were perfused with 4% paraformaldehyde. Cochleae and brainstems were taken out and processed for surface preparations and frozen sections. Immunoperoxidase immunohistochemistry was carried out using anti-CGRP polyclonal antibody. RESULTS: Numerous CGRP immunoreactive fibers were located in the inner spiral bundle, intraganglionic nerve fibers, base of inner hair cells and lateral superior olivary nuclei in brainstems. CONCLUSION: CGRP is one of the neuropeptides in the olivocochlear effent system and may participate in the inhibitory effect on auditory action potential.