Automated detection of auditory response: non-detection stopping criterion and repeatability studies for multichannel EEG.

An Auditory Steady-State Response (ASSR) is a valuable tool for determining auditory thresholds in individuals who are either unable or unwilling to cooperate with conventional behavioral testing methods. This study proposes a sequential test technique for automatic detection of ASSRs, incorporating a non-detection stopping criterion. The electrophysiological thresholds of a normal hearing volunteer were established using data collected from multichannel EEG signals. The detection probabilities and critical values were obtained via Monte Carlo simulations. Remarkably, application of the non-detection stopping criterion resulted in a 60% reduction in exam time in the absence of a response. These findings clearly demonstrate the significant potential of the sequential test in enhancing the performance of automatic audiometry.

Dealing with correlations in the multichannel EEG using bipolar derivations and Monte Carlo simulations: application to the detection of auditory steady-state responses.

The multichannel objective response detection (MORD) techniques are statistical methods, which use information from more than one electroencephalography (EEG) channel, to infer the presence of evoked potential. However, the correlation level between the channels can lead to a decrease in MORD performance, such as an increase in the false positive (FP) rate and/or a decrease in the detection rate (DR). The present study aims to propose a method to deal with the correlations in the multichannel EEG. The method consists of making an adjustment in the Monte Carlo simulation, considering the information between channels. The MORD techniques with and without the new method were applied to an auditory steady-state response (ASSR) database, composed of the EEG multichannel of eleven volunteers during multifrequency stimulation. The proposed method kept the FP rate at values equal to or less than the significance level of the test and led to an increase of 8.51% in the DR in relation to non-application of the method. Results of this study indicate that the proposed method is an alternative to deal with the effect of the correlation between channels in situations where MORD techniques are applied.

Pure-Tone Hearing Thresholds and Brainstem Auditory Evoked Potentials in Sporadic Ataxia

Abstract Introduction Spinocerebellar ataxia (SCA) is part of a genetic and clinical heteroge- neous group of neurodegenerative diseases characterized by progressive cerebellar ataxia. Objective To describe the results of audiological and electrophysiological hearing evaluations in patients with sporadic ataxia (SA). Methods A retrospective cross-sectional study was carried out with 11 patients submitted to the following procedures: anamnesis, otorhinolaryngological evaluation, tonal and vocal audiometry, acoustic immittance and brainstem auditory evoked potential (BAEP) tests. Results The patients presented with a prevalence of gait imbalance, of dysarthria, and of dysphagia; in the audiometric and BAEPs, four patients presented with alterations; in the acoustic immittance test, five patients presented with alterations, predominantly bilateral. Conclusion The most evident alterations in the audiological evaluation were the prevalence of the descending audiometric configuration between the frequencies of 2 and 4 kHz and the absence of the acoustic reflex between the frequencies of 3 and 4 kHz bilaterally. In the electrophysiological evaluation, the patients presented changes with a prevalence of increased I, III and V wave latencies and the interval in the interpeak I-III, I-V and III-V. In the present study, it was observed that auditory complaints did not have a significant prevalence in this type of ataxia, which does not occur in some types of autosomal recessive and dominant ataxia.

Pure-Tone Hearing Thresholds and Brainstem Auditory Evoked Potentials in Sporadic Ataxia.

Introduction Spinocerebellar ataxia (SCA) is part of a genetic and clinical heterogeneous group of neurodegenerative diseases characterized by progressive cerebellar ataxia. Objective To describe the results of audiological and electrophysiological hearing evaluations in patients with sporadic ataxia (SA). Methods A retrospective cross-sectional study was carried out with 11 patients submitted to the following procedures: anamnesis, otorhinolaryngological evaluation, tonal and vocal audiometry, acoustic immittance and brainstem auditory evoked potential (BAEP) tests. Results The patients presented with a prevalence of gait imbalance, of dysarthria, and of dysphagia; in the audiometric and BAEPs, four patients presented with alterations; in the acoustic immittance test, five patients presented with alterations, predominantly bilateral. Conclusion The most evident alterations in the audiological evaluation were the prevalence of the descending audiometric configuration between the frequencies of 2 and 4 kHz and the absence of the acoustic reflex between the frequencies of 3 and 4 kHz bilaterally. In the electrophysiological evaluation, the patients presented changes with a prevalence of increased I, III and V wave latencies and the interval in the interpeak I-III, I-V and III-V. In the present study, it was observed that auditory complaints did not have a significant prevalence in this type of ataxia, which does not occur in some types of autosomal recessive and dominant ataxia.

Seizure Susceptibility Corrupts Inferior Colliculus Acoustic Integration.

Evidence suggests that the pathophysiology associated with epileptic susceptibility may disturb the functional connectivity of neural circuits and compromise the brain functions, even when seizures are absent. Although memory impairment is a common comorbidity found in patients with epilepsy, it is still unclear whether more caudal structures may play a role in cognitive deficits, particularly in those cases where there is no evidence of hippocampal sclerosis. This work used a genetically selected rat strain for seizure susceptibility (Wistar audiogenic rat, WAR) and distinct behavioral (motor and memory-related tasks) and electrophysiological (inferior colliculus, IC) approaches to access acoustic primary integrative network properties. The IC neural assemblies' response was evaluated by auditory transient (focusing on bottom-up processing) and steady-state evoked response (ASSR, centering on feedforward and feedback forces over neural circuitry). The results show that WAR displayed no disturbance in motor performance or hippocampus-dependent memory tasks. Nonetheless, WAR animals exhibited significative impairment for auditory fear conditioning (AFC) along with no indicative of IC plastic changes between the pre-conditioning and test phases (ASSR coherence analysis). Furthermore, WAR's IC response to transient stimuli presented shorter latency and higher amplitude compared with Wistar; and the ASSR analysis showed similar results for WAR and Wistar animals under subthreshold dose of pentylenetetrazol (pro-convulsive drug) for seizure-induction. Our work demonstrated alterations at WAR IC neural network processing, which may explain the associated disturbance on AFC memory.

Auditory processing disorder evaluations and cognitive profiles of children with specific learning disorder.

OBJECTIVE: This study investigated the auditory sensory-perceptual level of specific learning disorder (SLD) and explored relationships among neuropsychological assessments for SLD, auditory processing, and short and long latencies of auditory event-related potentials (ERPs). METHODS: Fifteen children (7-14 years old) comprised the control group; 34 children comprised the SLD group. Audiologic assessments included tone audiometry, acoustic immittance measurements, acoustic reflex, central auditory processing, brainstem evoked response audiometry, and long latency potentials (P3 and N2). Children's intelligence levels were assessed with 2 intelligence batteries, 1 verbal and 1 non-verbal, as well as with visuomotor skills. RESULTS: Multiple regression showed a significant interaction effect of APE tests and P3/N2 over Wechsler Scale performance in freedom of distractibility indexes and multiple subtests. Errors in the Bender Visual Motor Gestalt Test were predicted by lower parental education, lower performance in APE tests: dichotic digits and pediatric/synthetic sentence identification-ipsilateral, and longer P3/N2 latencies, particularly regarding integration and rotation distortions. CONCLUSIONS: Children with altered auditory processing exhibit a specific cognitive profile, including lower verbal and spatial reasoning performance, that is sensitive to parental education level. SIGNIFICANCE: Children with SLD should undergo a complete multimodal examination to identify their specific difficulties and needs.

Applicability of Evoked Auditory Brainstem Responses with Complex Stimuli in Adults with Hearing Loss.

Introduction The use of the speech-evoked auditory brainstem response (ABR) shows how the brainstem operates up to the subcortex in a more complex manner than when the click-evoked ABR is used. Objective To study the applicability of the speech-evoked ABR in adults with hearing loss. Methods The sample was composed of a study group of 11 subjects, with ages ranging between 18 and 59 years, and auditory thresholds within normal standards, with loss of up to 65 dB at high frequencies or up to moderately severe symmetric sensorineural hearing loss. The sample underwent a basic audiological assessment, as well as speech-evoked ABR and click-evoked ABR, in which waves I, III and V, and V, A, C, D, E, F were respectively marked. The electrophysiological assessments were performed using the SmartEP device (Intelligent Hearing Systems, Miami, FL, US). Results For the speech-evoked ABR, the reference values were used in the identification and analysis of the study group. Those values found for the study group were: V = 8.56; A = 10.97; C = 21.33; D = 29.51; E = 37.93; F = 46.96; and O = 55.97. In the comparison between groups, the study group presented an increase in latency only in wave C. Conclusion The speech-evoked ABR can be performed in subjects with up to moderately severe hearing loss, and the test proved to be appropriate, because, unlike the click-evoked ABR, the former does not suffer influence of peripheral hearing loss.

Applicability of Evoked Auditory Brainstem Responses with Complex Stimuli in Adults with Hearing Loss

Abstract Introduction The use of the speech-evoked auditory brainstem response (ABR) shows how the brainstem operates up to the subcortex in a more complexmanner than when the click-evoked ABR is used. Objective To study the applicability of the speech-evoked ABR in adults with hearing loss. Methods The sample was composed of a study group of 11 subjects, with ages ranging between 18 and 59 years, and auditory thresholds within normal standards, with loss of up to 65 dB at high frequencies or up to moderately severe symmetric sensorineural hearing loss. The sample underwent a basic audiological assessment, as well as speech-evoked ABR and click-evoked ABR, in which waves I, III and V, and V, A, C, D, E, F were respectively marked. The electrophysiological assessments were performed using the SmartEP device (Intelligent Hearing Systems, Miami, FL, US). Results For the speech-evoked ABR, the reference values were used in the identification and analysis of the study group. Those values found for the study group were: V = 8.56; A = 10.97; C = 21.33; D = 29.51; E = 37.93; F = 46.96; and O = 55.97. In the comparison between groups, the study group presented an increase in latency only in wave C. Conclusion The speech-evoked ABR can be performed in subjects with up to moderately severe hearing loss, and the test proved to be appropriate, because, unlike the click-evoked ABR, the former does not suffer influence of peripheral hearing loss.

Análise da diferença entre os limiares auditivos comportamentais e os resultados obtidos através do exame potencial evocado auditivo de estado estável (PEAEE) em adultos jovens / Analysis of difference between the behavioral hearing thresholds and the results obtained through the auditory steady state response (ASSR) in young adults / Análisis de la diferencia entre los umbrales auditivos comportamentales y los resultados obtenidos a través del examen potencial evocado auditivo de estado estable (PEAEE) en adultos jóvenes

Introdução: A audição, sentido que nos permite receber a informação sonora, se apresenta como um dos facilitadores para uma interação social eficaz. Um déficit nessa função acarreta prejuízo no processo comunicativo, devendo ser diagnosticado e tratado precocemente. Atualmente dispomos de meios subjetivos e objetivos para avaliar o sistema auditivo. A audiometria tonal é a forma subjetiva mais aplicada para medir esse sentido. Entretanto, em populações impossibilitadas de responder subjetivamente, aplicam-se técnicas objetivas, como o Potencial Evocado Auditivo de Estado Estável. Ambos pesquisam respostas auditivas do sujeito sob teste, utilizando técnicas distintas. Objetivo: Avaliar adultos jovens, sem queixas auditivas, pesquisando a sensibilidade auditiva e, a partir de indicadores estatísticos, calcular as médias das diferenças das respostas obtidas nesses procedimentos, verificando se há correlação entre eles. Método: Pesquisa de respostas auditivas via Audiometria Tonal e Potencial Evocado Auditivo de Estado Estável, nas frequências de 500, 1000, 2000 e 4000 Hz, em 30 sujeitos normo-ouvintes. Resultados: Ao calcularmos a média das diferenças entre as frequências testadas nos dois procedimentos, elas variaram de 10,47 a 18,22, não havendo forte correlação em nenhuma delas, deixando dúvidas na frequência de 1000 Hz. Conclusão: Podemos dizer que as médias das diferenças entre os valores obtidos nos dois procedimentos foram razoavelmente elevadas, principalmente em 500 Hz e, em menor proporção, para 4 kHz. Os valores obtidos nos dois exames, embora não tenham apresentado forte correlação, apresentaram-se discretamente melhores para 500 Hz. Resultados de 1000 Hz não nos permitem afirmar, inclusive, se existe alguma correlação entre os testes.

Introduction: Hearing is the sense which allows us to receive auditory information; therefore it facilitates efficient social interaction. Any loss in this function damages the communicative process, so it must be diagnosed and treated as soon as possible. Nowadays, both objective and subjective hearing tests are available. Pure Tone Audiometry is the most widely used subjective way to evaluate this sense. However, for those who are unable to respond subjectively, we can try objective techniques like the Auditory Steady State Response. Both will search for patients' minimum hearing responses, applying different approaches. Objective: To evaluate normal-hearing young adults with no hearing complaints by analyzing their hearing sensibility and, based on statistical indicators, calculate the average of the differences between the results obtained in both procedures in order to verify the existence of correlation between them. Method: We studied the hearing responses from 30 normal-hearing subjects through Pure Tone Audiometry and Auditory Steady State Response at 500, 1000, 2000 and 4000 Hz. Results: When we calculated the average of the differences between the tested frequencies, they ranged from 10,47 to 18,22 with no strong correlation, except at 1000 Hz whose results were uncertain. Conclusion: We concluded that the average of the differences of hearing values obtained in Pure Tone Audiometry and Auditory Steady State Response were reasonably elevated mainly at 500 Hz, and at a lower level at 4000 Hz. Although the scores obtained in both tests had not shown strong correlation, they were slightly better at 500 Hz. The results for 1000 Hz are inconclusive regarding any existing correlation between these two tests.

Introducción: La audición, sentido que nos permite recibir la información sonora, se presenta como uno de los facilitadores para una interacción social eficaz. Un déficit en esta función acarrea perjuicio en el proceso comunicativo, lo que debe ser diagnosticado y tratado lo antes posible. Actualmente disponemos de medios subjetivos y objetivos para evaluar el sistema auditivo. La audiometría tonal es la forma subjetiva más aplicada para medir ese sentido. Sin embargo, en poblaciones imposibilitadas de responder subjetivamente, se aplican técnicas subjetivas como el Potencial Evocado Auditivo de Estado Estable. Ambas investigan las respuestas auditivas del sujeto bajo test, utilizando técnicas distintas. Objetivo: Evaluar a adultos jóvenes, sin quejas auditivas, investigando la sensibilidad auditiva y, a partir de los indicadores estadísticos, calcular los promedios de la diferencias de las respuestas obtenidas en esos procedimientos, y comprobar si existe correlación entre ellos. Método: Pesquisa de respuestas auditivas vía Audiometría Tonal y Potencial Evocado Auditivo de Estado Estable en las frecuencias de 500,1000, 2000 y 4000 Hz, en 30 sujetos oyentes normales. Resultados: Tras el cálculo del promedio de las diferencias entre las frecuencias testadas en los dos procedimientos, se pudo verificar una variación de 10,47 a 18,22, donde no se ha registrado fuerte correlación en ninguna de ellas, dejando duda en la frecuencia de 1000 Hz. Conclusión: Podemos decir que los promedios de las diferencias entre los valores obtenidos en los dos procedimientos fueron razonablemente elevados, sobre todo en 500 Hz y, en menor proporción, para 4kHz. Los valores que se obtuvieron en los dos exámenes, aunque no hayan presentado fuerte correlación, se presentaron discretamente mejores para 500 Hz. Resultados de 1000 Hz no nos permiten afirmar, incluso, si hay alguna correlación entre los testes.

Multivariate evoked response detection based on the spectral F-test.

BACKGROUND: Objective response detection techniques, such as magnitude square coherence, component synchrony measure, and the spectral F-test, have been used to automate the detection of evoked responses. The performance of these detectors depends on both the signal-to-noise ratio (SNR) and the length of the electroencephalogram (EEG) signal. NEW METHOD: Recently, multivariate detectors were developed to increase the detection rate even in the case of a low signal-to-noise ratio or of short data records originated from EEG signals. In this context, an extension to the multivariate case of the spectral F-test detector is proposed. RESULTS: The performance of this technique is assessed using Monte Carlo. As an example, EEG data from 12 subjects during photic stimulation is used to demonstrate the usefulness of the proposed detector. COMPARISON WITH EXISTING METHOD(S): The multivariate method showed detection rates consistently higher than those ones when only one signal was used. CONCLUSIONS: It is shown that the response detection in EEG signals with the multivariate technique was statistically significant if two or more EEG derivations were used.

Electrocochleography for Ménière's disease: is it reliable?

INTRODUCTION: Endolymphatic hydrops, the histopathological substrate of Ménière's disease, is an almost universal finding in postmortem studies of patients with this disease. The cause of hydrops is still unknown, as is the mechanism by which it causes progressive dysfunction of the sensory organs of inner ear. The fluctuating course of the disease complicates the interpretation of certain tests, such as electrocochleography; thus, for some authors its diagnostic value is questionable. OBJECTIVE: The aim of this study was to analyze the clinical applicability of electrocochleography in the diagnosis of hydrops. It is a valuable tool, but still generates conflicting opinions among otolaryngologists. METHODS: Systematic review of the literature on electrocochleography in patients diagnosed with endolymphatic hydrops. RESULTS: A total of 34 articles regarding the use of electrocochleography in patients with hydrops, from the year 2000 onwards, were selected. Of these, 15 were excluded from the review as they were not observational studies. Only one cross-sectional study addressing the clinical use of electrocochleography by otolaryngologists was included. CONCLUSION: Electrocochleography is a valuable tool in the diagnosis of hydrops, as it is a non-invasive, easy to handle procedure, which offers new techniques to increase the sensitivity of the test, and thereby assists otolaryngologists in the management of Ménière's disease.

Electrocochleography for Ménière's disease: is it reliable?, / Eletrococleografia na doença de Ménière: é confiável?,

Introduction: Endolymphatic hydrops, the histopathological substrate of Ménière's disease, is an almost universal finding in postmortem studies of patients with this disease. The cause of hydrops is still unknown, as is the mechanism by which it causes progressive dysfunction of the sensory organs of inner ear. The fluctuating course of the disease complicates the interpretation of certain tests, such as electrocochleography; thus, for some authors its diagnostic value is questionable. Objective: The aim of this study was to analyze the clinical applicability of electrocochleography in the diagnosis of hydrops. It is a valuable tool, but still generates conflicting opinions among otolaryngologists. Methods: Systematic review of the literature on electrocochleography in patients diagnosed with endolymphatic hydrops. Results: A total of 34 articles regarding the use of electrocochleography in patients with hydrops, from the year 2000 onwards, were selected. Of these, 15 were excluded from the review as they were not observational studies. Only one cross-sectional study addressing the clinical use of electrocochleography by otolaryngologists was included. Conclusion: Electrocochleography is a valuable tool in the diagnosis of hydrops, as it is a non-invasive, easy to handle procedure, which offers new techniques to increase the sensitivity of the test, and thereby assists otolaryngologists in the management of Ménière's disease. .

Introdução: A hidropisia endolinfática é o substrato histopatológico e achado quase universal nos estudos post-mortem de pacientes com doença de Ménière. A causa da hidropisia ainda é desconhecida, assim como o mecanismo pelo qual causa disfuncção progressiva dos órgãos sensitivos da orelha interna. O curso flutuante da doença dificulta a interpretação de exames como a eletrococleografia, que apresenta, para alguns autores, valor diagnóstico controverso. Objetivos: O objetivo deste estudo é analisar a aplicabilidade clínica da eletrococleografia no diagnóstico da hidropisia endolinfática, sendo uma ferramenta de uso comum e que ainda gera opiniões conflitantes entre os otorrinolaringologistas. Método: Revisão sistemática da literatura sobre eletrococleografia em pacientes com diagnóstico de hidropisia endolinfática. Resultados: Foram selecionados 34 artigos sobre o uso da eletrococleografia em pacientes portadores de hidropisia endolinfática a partir do ano 2000; 15 artigos foram excluídos da revisão por não se tratarem de estudos observacionais, com inclusão de somente um estudo transversal que trata sobre o uso clínico da eletrococleografia entre os otorrinolaringologistas. Conclusão: A eletrococleografia é uma importante ferramenta no diagnóstico da hidropisia endolinfática, por ser não invasiva, de fácil mensuração, e por oferecer novas técnicas capazes de aumentar a sensibilidade do exame e auxiliar o otorrinolaringologista no tratamento da Doenca de Ménière. .

Potencial evocado auditivo de tronco encefálico por frequência específica por via aérea e via óssea em neonatos ouvintes normais / Air and bone-conduction frequency-specific auditory brainstem response in neonates with normal hearing

Objetivo determinar os níveis mínimos de resposta (NMR) e a latência da onda V do Potencial Evocado Auditivo de Tronco encefálico por Frequência específica (PEATE-FE) em neonatos ouvintes normais nas frequências de 0.5, 1, 2 e 4 kHz por via aérea e via óssea e determinar valores normativos. Métodos foram avaliados neonatos com audição normal, sendo realizado o PEATE-FE nas frequências de 0.5, 1, 2 e 4 kHz, tanto por via aérea (VA) quanto por via óssea (VO). Para cada frequência, foram avaliadas 12 orelhas em um total de 18 neonatos. A análise dos resultados avaliou o tempo de latência e a presença da onda V até a intensidade de 20 dBnNA para quatro intensidades e para os dois tipos de condução (aérea e óssea). Resultados observou-se aumento da latência da onda V com a diminuição da intensidade e maiores latências nas frequências mais baixas, tanto na VA quanto na VO. Porém, em fortes intensidades, em ambas condições, não houve diferença entre as latências de 0.5 e 1 kHz, contrariando os achados da literatura. Para VA, na frequência de 500 Hz, houve presença da onda V até 30 dBnNA em todas as orelhas, e em 1000 Hz, 11 orelhas (91,66 %) apresentaram resposta em 20 dBnNA; nas demais frequências, 100% das orelhas avaliadas apresentaram resposta em 20 dBnNA. Na VO, a presença da onda V em 20 dBnNA foi observada em todas as frequências estudadas. Conclusão os valores descritos podem ser considerados normativos e utilizados na clinica como padrão de normalidade, auxiliando no diagnóstico diferencial da perda auditiva ao nascimento. .

Purpose to determine the minimum response and the latency of V wave in the Frequency-specific auditory brainstem responses (FS-ABR) in normal hearing neonates at the frequencies: 0.5, 1, 2 and 4 kHz by air and bone conduction and to determine normative values. Methods normal hearing neonates were assessed with FS-ABR at 0.5, 1, 2 and 4 kHz, air and bone conduction. Twelve ears were assessed in each frequency, totalizing 18 neonates. Results analysis considered the latency and the presence of wave V until 20 dB nHL in air and bone conduction, for four intensities. Results it was observed an increase of wave V latency with the decrease of intensity, and greater latencies at lower frequencies in both air and bone conduction. Nevertheless, there was no difference between the latencies at 0.5 and 1 kHz with strong intensity stimuli in both conditions, contrasting to literature findings. Considering air conduction, wave V was present at 0,5 kHz at 30 dB nHL in all ears and at 1 kHz 11 ears (91,66%) presented it at 20 dB nHL. All subjects (100%) presented responses to the other frequencies at 20 dBn HL. Considering bone conduction, all subjects presented wave V at 20 dB nHL in all frequencies. Conclusion the found values can be used in clinical practice in order to guide the differential diagnosis of hearing loss, complementing the evaluation as for hearing neonates. .

Auditory evoked potentials: predicting speech therapy outcomes in children with phonological disorders

OBJECTIVES: This study investigated whether neurophysiologic responses (auditory evoked potentials) differ between typically developed children and children with phonological disorders and whether these responses are modified in children with phonological disorders after speech therapy. METHODS: The participants included 24 typically developing children (Control Group, mean age: eight years and ten months) and 23 children clinically diagnosed with phonological disorders (Study Group, mean age: eight years and eleven months). Additionally, 12 study group children were enrolled in speech therapy (Study Group 1), and 11 were not enrolled in speech therapy (Study Group 2). The subjects were submitted to the following procedures: conventional audiological, auditory brainstem response, auditory middle-latency response, and P300 assessments. All participants presented with normal hearing thresholds. The study group 1 subjects were reassessed after 12 speech therapy sessions, and the study group 2 subjects were reassessed 3 months after the initial assessment. Electrophysiological results were compared between the groups. RESULTS: Latency differences were observed between the groups (the control and study groups) regarding the auditory brainstem response and the P300 tests. Additionally, the P300 responses improved in the study group 1 children after speech therapy. CONCLUSION: The findings suggest that children with phonological disorders have impaired auditory brainstem and cortical region pathways that may benefit from speech therapy. .

Estudo comparativo entre audiometria tonal limiar e resposta auditiva de estado estavel em normouvintes / Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects

Introdução: As respostas auditivas de estado estável permitem avaliar de forma objetiva limiares auditivos frequência-específica. A audiometria tonal é o exame padrão-ouro; no entanto, nem sempre pode ser conclusiva, principalmente em crianças e adultos não colaborativos. Objetivo: Comparar os limiares auditivos da RAEE aos da audiometria tonal em indivíduos com audição normal. Materiais e métodos: Foram incluídos neste estudo prospectivo de corte transversal 26 adultos (52 orelhas), de ambos os gêneros, com audiometria normal e sem queixas otológicas. Os pacientes foram submetidos a anamnese, otomicroscopia, audiometria e imitanciometria. A seguir, realizou-se avaliação de respostas auditivas de estado estável. Os resultados obtidos foram analisados estatisticamente e comparados entre si. Resultados: A diferença entre os limiares (em dB NA) obtidos em ambos os exames para cada frequência testada foi de 7,12 dB para 500 Hz; 7,6 dB para 1000 Hz; 8,27 dB para 2000 Hz e 9,71 dB para 4000 Hz, com limiares mais elevados na RAEE, em todas as frequências. Não houve diferença estatística entre as médias para cada frequência testada. Conclusão: Os limiares obtidos na RAEE foram comparáveis aos da audiometria tonal em indivíduos normouvintes; entretanto, não deve ser usado como único método de avaliação auditiva. .

Introduction: Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. Aim: Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. Materials and methods: In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. Results: The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. Conclusion: ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation. .

Dental developmental abnormalities in a patient with subtelomeric 7q36 deletion syndrome may confirm a novel role for the SHH gene.

Studies in mice demonstrated that the Shh gene is crucial for normal development of both incisors and molars, causing a severe retardation in tooth growth, which leads to abnormal placement of the tooth in the jaw and disrupted tooth morphogenesis. In humans the SHH gene is located on chromosome 7q36. Defects in its protein or signaling pathway may cause holoprosencephaly spectrum, a disorder in which the developing forebrain fails to correctly separate into right and left hemispheres and that can be manifested in microforms such as single maxillary central incisor. A novel role for this gene in the developing human primary dentition was recently demonstrated. We report a 12-year old boy with a de novo 7q36.1-qter deletion characterized by high-resolution karyotyping, oligonucleotide aCGH and FISH. His phenotype includes intellectual disability, non-verbal communication, hypospadia, partial sacral agenesis and absence of coccyx, which are distinctive features of the syndrome and mainly correlated with the MNX1, HTR5A and EN2 genes. No microforms of holoprosencephaly spectrum were observed; but the patient had diastema and dental developmental abnormalities, such as conical, asymmetric and tapered inferior central incisors. The dental anomalies are reported herein for the first time in subtelomeric 7q36 deletion syndrome and may confirm clinically a novel role for the SHH gene in dental development.

Latent iron deficiency in utero is associated with abnormal auditory neural myelination in ≥ 35 weeks gestational age infants.

OBJECTIVE: To determine whether cord serum ferritin level is associated with auditory brainstem evoked response interpeak latencies, an index of auditory neural myelination, in infants at ≥ 35 weeks gestational age (GA). STUDY DESIGN: This prospective study compared auditory neural myelination in infants with latent iron deficiency (cord serum ferritin, 11-75 ng/mL) and infants with normal iron status (cord serum ferritin, >75 ng/mL) at birth. Our inclusion criteria were infants born at ≥ 35 weeks GA who had cord blood collected soon after birth and had 1 or more of the following risk factors for poor in utero iron status: maternal diabetes mellitus, pregnancy-induced hypertension, and intrauterine growth restriction. Cord serum ferritin level was measured using the chemiluminescence immunoassay method. Auditory brainstem evoked response was measured using 80-dB normal hearing level click stimuli at a rate of 69.9/second within 48 hours after birth to evaluate interpeak latencies, a measure of nerve conduction velocity or myelination. RESULTS: Of the 45 infants studied, 12 had latent iron deficiency. On repeated-measures ANCOVA using interpeak latencies I-III, III-V, and I-V as multiple outcomes, infants with latent iron deficiency had significantly prolonged interpeak latencies (P = .01) compared with infants with normal iron status after controlling for confounders. CONCLUSION: In utero latent iron deficiency is associated with abnormal auditory neural myelination at birth in infants born at ≥ 35 weeks GA.

Comparing auditory brainstem responses (ABRs) to toneburst and narrow band CE-chirp in young infants.

OBJECTIVE: The difference of characteristics (latency and amplitude) between toneburst and narrow CE-chirp stimuli on ABR recording was analyzed in normal hearing infants. METHODS: 500, 1000, 2000 and 4000 Hz toneburst and narrow band CE-chirp auditory brainstem responses (ABRs) were recorded in 40 normal-hearing infants. The amplitude and latency parameters of the ABR were collected for each of the four stimulus levels: 80, 60, 40, and 20 dB nHL. Both stimuli started from 80 dB nHL using alternating polarity and the rates were both 27.1/s. RESULTS: The toneburst latencies are greater than narrow band CE-chirp latencies for all intensities at 500, 1000 and 2000 Hz (p < 0.001). However, at 4000 Hz this difference was not significant. At 500 Hz, wave V amplitude is larger for toneburst than narrow CE-chirp (p < 0.001) in 80 dB nHL. The difference between the two stimuli in 60 dB nHL was not significant (p = 0.495) and at 40 and 20 dB nHL the wave V narrow band CE-chirp amplitude is greater than toneburst amplitude (p < 0.001). At 1000, 2000 and 4000 Hz there is no difference between the wave V toneburst and narrow band CE-chirp amplitudes at 80 dB nHL (p = 0.940; p = 0.776 and p = 0.217 respectively). On the other hand, in the levels to 60, 40 and 20 dB nHL, narrow band CE-chirp amplitudes are larger than toneburst amplitude (p < 0.001). CONCLUSION: Narrow band CE-chirp ABRs generates shorter latencies than the toneburst ABRs, especially to low frequencies. Higher amplitudes were found with narrow band CE-chirp stimuli for all frequencies tested, except to high levels.

Correlação dos achados do PEATE-FE e da avaliação comportamental em crianças com deficiência auditiva / Correlation between frequency-specific auditory brainstem responses and behavioral hearing assessment in children with hearing loss

OBJETIVO: analisar e correlacionar os achados dos Potenciais Evocados Auditivos de Tronco Encefáico por Frequência Específica e da avaliação comportamental, por Via aérea e Via óssea, em crianças com perda auditiva sensorioneural ou mista. MÉTODO: a casuística foi composta por dez crianças com até três anos de idade, diagnosticadas com perda auditiva sensorioneural. Foram realizados os PEATE-FE nas frequências de 0.5, 1, 2 e 4 kHz e a audiometria comportamental nas mesmas frequências, tanto por via aérea como por via óssea. Os resultados dos dois procedimentos foram correlacionados afim de verificar se o PEATE-FE é capaz de predizer o status auditivo de crianças com deficiência auditiva. RESULTADOS: os resultados mostraram forte correlação entre os dois procedimento nas quatro frequências estudadas por via aérea; já na via óssea, foi encontrada forte correlação nas frequências de 0.5, 1 e 2 kHz e moderada em 4 kHz. CONCLUSÃO: os PEATE-FE estimaram a audição com forte precisão quando comparados à audiometria comportamental. Desta forma, a aplicação dos PEATE-FE possibilita a estimativa da audição até que possam ser determinados, com segurança, os limiares comportamentais na população estudada.

PURPOSE: analyze and correlate the findings of the frequency specific auditory brainstem response and behavioral assessment by air and bone conduction in children with sensorineural hearing loss or mixed hearing loss. METHOD: the sample was composed of ten children up to three years old, diagnosed with sensorineural hearing loss. We conducted the FS-ABR in the frequencies of 0.5, 1, 2 and 4 kHz and behavioral audiometry in the same frequencies, by air and bone conduction. The results of both procedures were correlated in order to verify if the FS-ABR is able to predict auditory status of children with hearing impairment. RESULTS: it was observed a strong correlation between the two procedures in the four frequencies studied by air conduction; for bone conduction, found a strong correlation was found in the frequencies of 0.5, 1 and 2 kHz and a moderate correlation at 4 kHz. CONCLUSION: FS-ABR estimated the hearing with strong accuracy when compared to behavioral audiometry. Thus, the application of FS-ABR enables the estimation of hearing status until they can be determined by behavioral hearing tests in the population studied.

Dificuldades na comunicação em normo-ouvintes: estudo comportamental e eletrofisiológico / Communication disorders in subjects with normal hearing: a behavioral and electrophysiological study

Olimiar auditivo nem sempre prediz o desempenho em ambientes com redundância extrínseca reduzida. OBJETIVO: Investigar o relato de dificuldades de comunicação de adultos com audiograma normal e verificar o quadro subjacente por meio de avaliações comportamental e eletrofisiológica. MÉTODO: Estudo caso-controle de indivíduos com limiares normais, distribuídos em dois grupos: grupo estudo, 10 adultos com queixas auditivas de comunicação e grupo controle, 10 adultos, sem queixas. Foi medida a frequência em que os participantes apresentam dificuldades de comunicação e realizados testes de fala no silêncio e no ruído, audiometria e potencial evocado auditivo de tronco encefálico. RESULTADOS: O grupo estudo se diferenciou estatisticamente do grupo controle apenas nos escores de dificuldades de comunicação. Foi constatada uma correlação positiva entre os limiares tonais e os escores no autorrelato de dificuldade. CONCLUSÃO: A presença de queixa auditiva na ausência de alterações no audiograma não esteve associada a diferença no desempenho no reconhecimento de fala no ruído, nem nas demais avaliações. Com base na análise de correlação, observou-se que, quanto mais elevados os limiares auditivos, maiores os escores no relato de dificuldades auditivas relacionadas às situações de comunicação, mesmo os limiares variando de 0 a 25 dB.

Hearing thresholds are not always predictive of performance in environments with reduced extrinsic redundancy. OBJECTIVE: To investigate the communication disorders reported by adults with normal hearing, and to assess their underlying conditions through behavioral and electrophysiological testing. METHOD: This case control study enrolled 20 adults with normal hearing thresholds and divided them into two groups: a case group with 10 adults with hearing impairment-related communication disorders and a control group with 10 adults with normal hearing. The frequency of occurrence of communication difficulties was recorded during speech recognition tests run in quiet and noisy conditions, audiometry, and auditory evoked brainstem potential testing. RESULTS: Case group subjects differed statistically from controls only in self-reported scores of hearing impairment. The groups did not differ in the other ratings. A positive correlation was found between hearing thresholds and scores on self-reported impairment. CONCLUSION: The combination of hearing complaints and unaltered audiograms was not correlated with differences in performance in speech recognition testing in noisy conditions or in the remaining evaluations. Correlation analysis showed that the higher the pure tone thresholds, the greater were the reported communication difficulties, even in thresholds between 0 and 25 dB.