The Auditory Steady-State Response and the Relationship between Electrophysiological and Behavioural Thresholds.

BACKGROUND: This study examined the relationship between behavioural thresholds as measured by pure tone audiometry and electrophysiological thresholds measured by the Auditory Steady-State Response (ASSR) in children with normal hearing and sensorineural hearing loss. MATERIALS AND METHODS: After being assessed, 45 children of both sexes, ranging in age from 5 to 15, were split into four groups: 10 with moderate to moderately severe sensorineural hearing loss (G2M); 10 with steeply sloping sensorineural hearing loss (G2D); 10 with profound and severe sensorineural hearing loss (G2S); and 15 with normal hearing (G1). ASSR, tympanometry, acoustic reflex testing, pure tone audiometry, and speech audiometry (SRT and SDT) were performed. RESULTS: The electrophysiological maximum in the group with normal hearing thresholds varied from 19 to 27 dB NA. The correlation in the group with moderate to moderately severe hearing loss was 0.42-0.74. The correlation in the steeply sloping hearing loss group was 0.68-0.94. The correlation in the group of people with profound and severe hearing loss was 0.59-0.86. The normal hearing group's mean differences in ASSR threshold and audiometric threshold ranged from -0.3 to 12 dB, in the moderate and moderately severe hearing loss group from -9 to 2 dB, in the steeply sloping hearing loss group from 1.4 to 7.5 dB, and in the severe and profound hearing loss group from -0.40 to 8.5 dB. CONCLUSION: As expected, there was no strong relationship between behavioural and electrophysiological thresholds in the group with normal hearing. But in children with hearing loss, there was a strong correlation between electrophysiological and behavioural thresholds; this relationship was especially evident in children with severe and profound hearing loss and those with steeply sloping hearing loss.

Peripheral and brainstem auditory evaluation in post-COVID-19 individuals.

PURPOSE: The purpose of this study was to investigate the peripheral and central auditory pathways in adult individuals after COVID-19 infection. METHOD: A total of 44 individuals aged between 19 and 58 years, of both genders, post-COVID-19 infection, confirmed by serological tests, with no previous hearing complaints and no risk factors for hearing loss, were assessed. All the participants underwent the following procedures: pure tone audiometry, logoaudiometry, immitanciometry, and Brainstem Auditory Evoked Potentials (BAEP), in addition to answering a questionnaire about auditory symptoms. RESULTS: Thirteen individuals (29.5 %) had some hearing threshold impairment, mainly sensorineural hearing loss. In the BAEP, 18 individuals (40.9 %) presented longer latencies, mainly in waves III and V. According to the questionnaire answers, 3 individuals (9.1 %) reported worsened hearing and 7 (15.9 %) tinnitus that emerged after the infection. As for the use of ototoxic drugs during treatment, 7 individuals (15.9 %) reported their use, of which 5 showed abnormalities in peripheral and/or central auditory assessments. CONCLUSION: Considering the self-reported hearing complaints after COVID-19 infection and the high rate of abnormalities found in both peripheral and central audiological assessments, it is suggested that the new COVID-19 may compromise the auditory system. Due to the many variables involved in this study, the results should be considered with caution. However, it is essential that audiological evaluations are carried out on post-COVID-19 patients in order to assess the effects of the infection in the short, medium, and long term. Future longitudinal investigations are important for a better understanding of the auditory consequences of COVID-19.

Assessment of Peripheral and Central Auditory Processing after Treatment for Idiopathic Sudden Sensorineural Hearing Loss.

Introduction When cases of idiopathic sudden sensorineural hearing loss (SSNHL) are treated successfully, most clinicians assume the normality and symmetry of the auditory processing. This assumption is based on the recovery of the detection ability on the part of the patients, but the auditory processing involves much more than detection alone. Since certain studies have suggested a possible involvement of the central auditory system during the acute phase of sudden hearing loss, the present study hypothesized that auditory processing would be asymmetric in people who have experienced sudden hearing loss. Objective To assess the physiologic and electrophysiological conditions of the cochlea and central auditory system, as well as behavioral discrimination, of three primary aspects of sound (intensity, frequency, and time) in subjects with normal ears and ears treated successfully for SSNHL. Methods The study included 19 SSNHL patients whose normal and treated ears were assessed for otoacoustic emissions, speech auditory brainstem response, intensity and pitch discrimination, and temporal resolution in a within-subject design. Results The otoacoustic emissions were poorer in the treated ears compared to the normal ears. Ear- and sex-dependent differences were observed regarding otoacoustic emissions and pitch discrimination. Conclusion The asymmetrical processing observed in the present study was not consistent with the hearing threshold values, which might suggest that the central auditory system would be affected regardless of the status of the peripheral hearing. Further experiments with larger samples, different recovery scenarios after treatment, and other assessments are required.

NeuroSense: A non-invasive and configurable somatosensory stimulator with OPENVIBE communication.

Understanding the somatosensory system and its abnormalities requires the development of devices that can accurately stimulate the human skin. New methods for assessing the somatosensory system can enhance the diagnosis, treatments, and prognosis for individuals with somatosensory impairments. Therefore, the design of NeuroSense, a tactile stimulator that evokes three types of daily life sensations (touch, air and vibration) is described in this work. The prototype aims to evoke quantitative assessments to evaluate the functionality of the somatosensory system and its abnormal conditions that affect the quality of life. In addition, the device has proven to have varying intensities and onset latencies that produces somatosensory evoked potentials and energy desynchronization on somatosensory cortex.

The Relationship between Speech Sound Disorder and Cortical Auditory Evoked Potential.

INTRODUCTION: Speech sound disorder (SSD) is a speech and language disorder associated with difficulties in motor production, perception, and phonological representation of sounds and speech segments. Since auditory perception has a fundamental role in forming and organizing sound representation for its recognition, studies that evaluate the cortical processing of sounds are required. Thus, the present study aimed to verify the relation between SSD severity measured by the percentage of correct consonants (PCCs) with the cortical auditory evoked potentials (CAEPs) using speech stimulus. METHODS: Twenty-nine children with normal hearing participated in this research and were grouped into three groups by SSD level measured by the PCC index. In addition, the groups were subdivided according to the children's age group: between 60-71 months, 72-83 months, and 83-94 months. The CAEP with speech stimulus was carried out in all children. RESULTS: Older children had longer P1 and N1 latencies. In P2 latency, there was an interference of age only in the severe group. The N2 latency was affected by age, where older children had longer latency. CONCLUSION: The amplitude of CAEP has not suffered any interference with the age, or severity of SSD. For the latency, older children generally presented longer averages than younger ones.

The Effect of Simultaneous Contralateral White Noise Masking on Cortical Auditory Evoked Potentials Elicited by Speech Stimuli.

Introduction Noise obscures speech signal, causing auditory masking. The effects of this masking can be observed through the cortical auditory evoked potentials (CAEPs). White noise, in turn, has an effect on the auditory cortex, interfering, for example, with lexical decision making. Objective To analyze the effect of simultaneous masking by contralateral white noise on CAEPs elicited by speech stimuli. Methods Cross-sectional observational analytical study carried out with 15 participants of both sexes, who were submitted to CAEPs in two conditions: 1) without noise; 2) with white noise at 100 dBSPL intensity, contralaterally and simultaneously. To compare these conditions, the Student t test or the Wilcoxon test were used, depending on the sample normality. Differences with p values < 0.05 were considered significant. Results : When white noise was presented contralaterally and simultaneously to the CAEPs with speech stimulus, an increase in P1, N1 and P2 wave latencies was observed. P1 and P2 amplitudes and N1-P2 peak to peak amplitude also increased, unlike N1 amplitude, which decreased. The differences were significant for P1 and P2 wave latencies and for P2 wave amplitude. Conclusion The simultaneous masking effect was observed from the morphological alterations of the CAEPs with speech stimulus when white noise was presented in the contralateral ear. There was a significant increase in P1 and P2 wave latencies, as well as in P2 wave amplitude.

Changes in Auditory Evoked Potentials Increase the Chances of Adults Having Central Auditory Processing Disorder.

Introduction Auditory evoked potentials are widely used in clinical practice to complement the assessment of central auditory processing. However, it is necessary to understand whether these potentials are highly accurate, to assist in the diagnosis of auditory processing disorder. Objective To measure the accuracy of middle and long latency auditory evoked potentials in the diagnosis of auditory processing disorder in adults. Methods This is a case-control study, formed by a control group of 30 individuals with normal auditory processing assessment, and a case group composed of 43 individuals with altered auditory processing assessment. Their sensitivities, specificities, accuracies, positive and negative predictive values for the diagnosis of alterations were measured and compared between the potentials. Results The accuracies of the middle and long latency potentials were 51% and 67%, respectively. The P1-N1-P2 and N2-P300 complexes had an accuracy of 57.5% and 58.9%, respectively. The cognitive potential P300 showed an accuracy of 55%. There was no significant result for the middle-latency potential (OR = 1.8; 95% CI: 0.6-5.4, p > 0.42) and for P300 (OR = 2.63, 95% CI: 0.85-8.43, p > 0.11). However, the result was significant for the long-latency potential (OR = 6.3; 95% CI: 2-19.6, p < 0.01). There was a significant result for the P1-N1-P2 complexes (OR = 6.76, 95% CI:1.4-32.5, p = < 0.010) and N2-P300 (OR = 3.60; 95% CI: 10.16-11.20, p < 0.039). Conclusion Individuals with altered long-latency auditory evoked potential are more likely to have auditory processing disorder and, as such, this test can be used as a complementary tool to confirm the diagnosis.

A High-Resolution LED Stimulator for Steady-State Visual Stimulation: Customizable, Affordable, and Open Source.

Visually evoked steady-state potentials (SSVEPs) are neural responses elicited by visual stimuli oscillating at specific frequencies. In this study, we introduce a novel LED stimulator system explicitly designed for steady-state visual stimulation, offering precise control over visual stimulus parameters, including frequency resolution, luminance, and the ability to control the phase at the end of the stimulation. The LED stimulator provides a personalized, modular, and affordable option for experimental setups. Based on the Teensy 3.2 board, the stimulator utilizes direct digital synthesis and pulse width modulation techniques to control the LEDs. We validated its performance through four experiments: the first two measured LED light intensities directly, while the last two assessed the stimulator's impact on EEG recordings. The results demonstrate that the stimulator can deliver a stimulus suitable for generating SSVEPs with the desired frequency and phase resolution. As an open source resource, we provide comprehensive documentation, including all necessary codes and electrical diagrams, which facilitates the system's replication and adaptation for specific experimental requirements, enhancing its potential for widespread use in the field of neuroscience setups.

Visual evoked potential abnormalities in patients with COVID-19

SUMMARY OBJECTIVE: It has been suggested that diseases that may cause visual evoked potential abnormality, such as optic neuritis, may be associated with the coronavirus disease 2019. This study aimed to find out whether there are visual evoked potential abnormalities in coronavirus disease 2019 patients using pattern reversal visual evoked potential and flash visual evoked potential. METHODS: Patients with a history of coronavirus disease 2019 (coronavirus disease 2019 patients) and controls were included in this prospective case-control study. This study was conducted in the Clinical Neurophysiology Laboratory of Adana City Training and Research Hospital. Individuals without visual impairment were included. Coronavirus disease 2019 patients were required to have clinical features consistent with previous acute infection and a positive nose swab polymerase chain reaction test. Visual evoked potential was applied to coronavirus disease 2019 patients between July 2020 and July 2021. Controls consisted of patients without a history of chronic disease who underwent a visual evoked potential study between June 2017 and June 2018 due to headache or dizziness. Pattern reversal visual evoked potential and flash visual evoked potential were applied to all participants. N75, P100, and N135 waves obtained from pattern reversal visual evoked potential and P1, N1, P2, N2, P3, and N3 waves obtained from flash visual evoked potential were analyzed. RESULTS: A total of 44 coronavirus disease 2019 patients and 40 controls were included in the study. Age and gender were not different between the two groups. Pattern reversal visual evoked potential parameters were not different between the two groups. Right P2 latency was 114.4±21.1 and 105.5±14.7 ms in coronavirus disease 2019 patients and controls, respectively (p=0.031). Patients with P100 and P2 wave abnormalities were 6 (13.6%) and 13 (29.6%), respectively. CONCLUSION: This study showed that there may be visual evoked potential abnormalities in coronavirus disease 2019 patients.

Changes in Auditory Evoked Potentials Increase the Chances of Adults Having Central Auditory Processing Disorder

Abstract Introduction Auditory evoked potentials are widely used in clinical practice to complement the assessment of central auditory processing. However, it is necessary to understand whether these potentials are highly accurate, to assist in the diagnosis of auditory processing disorder. Objective To measure the accuracy of middle and long latency auditory evoked potentials in the diagnosis of auditory processing disorder in adults. Methods This is a case-control study, formed by a control group of 30 individuals with normal auditory processing assessment, and a case group composed of 43 individuals with altered auditory processing assessment. Their sensitivities, specificities, accuracies, positive and negative predictive values for the diagnosis of alterations were measured and compared between the potentials. Results The accuracies of the middle and long latency potentials were 51% and 67%, respectively. The P1-N1-P2 and N2-P300 complexes had an accuracy of 57.5% and 58.9%, respectively. The cognitive potential P300 showed an accuracy of 55%. There was no significant result for the middle-latency potential (OR = 1.8; 95% CI: 0.6-5.4, p > 0.42) and for P300 (OR = 2.63, 95% CI: 0.85-8.43, p > 0.11). However, the result was significant for the long-latency potential (OR = 6.3; 95% CI: 2-19.6, p < 0.01). There was a significant result for the P1-N1-P2 complexes (OR = 6.76, 95% Cl:1.4-32.5, p = < 0.010) and N2-P300 (OR = 3.60; 95% CI: 10.16-11.20, p < 0.039). Conclusion Individuals with altered long-latency auditory evoked potential are more likely to have auditory processing disorder and, as such, this test can be used as a complementary tool to confirm the diagnosis.

The Effect of Simultaneous Contralateral White Noise Masking on Cortical Auditory Evoked Potentials Elicited by Speech Stimuli

Abstract Introduction Noise obscures speech signal, causing auditory masking. The effects of this masking can be observed through the cortical auditory evoked potentials (CAEPs). White noise, in turn, has an effect on the auditory cortex, interfering, for example, with lexical decision making. Objective To analyze the effect of simultaneous masking by contralateral white noise on CAEPs elicited by speech stimuli. Methods Cross-sectional observational analytical study carried out with 15 participants of both sexes, who were submitted to CAEPs in two conditions: 1) without noise; 2) with white noise at 100 dBSPL intensity, contralaterally and simultaneously. To compare these conditions, the Student t test or the Wilcoxon test were used, depending on the sample normality. Differences with p values < 0.05 were considered significant. Results: When white noise was presented contralaterally and simultaneously to the CAEPs with speech stimulus, an increase in P1, N1 and P2 wave latencies was observed. P1 and P2 amplitudes and N1-P2 peak to peak amplitude also increased, unlike N1 amplitude, which decreased. The differences were significant for P1 and P2 wave latencies and for P2 wave amplitude. Conclusion The simultaneous masking effect was observed from the morphological alterations of the CAEPs with speech stimulus when white noise was presented in the contralateral ear. There was a significant increase in P1 and P2 wave latencies, as well as in P2 wave amplitude.

Evaluation of the maturational auditory process in children with the infection by Zika congenital syndrome / Avaliação do processo maturacional auditivo em crianças portadoras da síndrome da infecção congênita pelo Zika vírus

ABSTRACT Purpose: to analyze the absolute latencies of waves I. III and V and the interpeak intervals I-III. III-V and I-V of the ABR recorded from different age groups of children with congenital zika virus infection and their peers without risk indicators for hearing impairment. Methods: 84 newborns and infants (N=51 study group and N=33 control group) divided into groups with different post-conceptual ages. with the results of their hearing exams analyzed by age group and compared with their peers without other risk indicators for hearing impairment. The assessment of the auditory pathway was conducted through tympanometry. otoacoustic emissions and auditory brain stem responses. Results: only the latency of wave I and the interpeak III-V showed no significant difference between the study and control groups. The absolute latency and interpeak values found in the study group were significantly lower than those found in the control group. Conclusion: the maturation of the brain stem in children with ZIKV infection occurred within normal limits. with no retrocochlear disorders until the age of 5 years.

RESUMO Objetivo: analisar as latências absolutas das ondas I. III e V e os intervalos interpicos I-III. III-V e I-V do Potencial Evocado Auditivo de Tronco Encefálico obtidos em diversos grupos etários de crianças portadoras de infecção congênita por zika vírus e nos seus pares sem indicadores de risco para deficiência auditiva. Métodos: foram recrutados 84 recém-nascidos e lactentes (N=51 grupo de estudo e N=33 grupo controle) separados por grupos com diferentes idades pós-conceptuais. sendo os resultados dos seus exames auditivos analisados por faixa etária e comparados com seus pares sem outros indicadores de risco para deficiência auditiva. A avaliação da via auditiva foi realizada por meio da timpanometria. emissões otoacústicas transientes e potencial evocado de tronco encefálico. Resultados: somente a latência da onda I e o intervalo interpico III-V não apresentaram diferença significante entre grupo de estudo e controle. Os valores de latências absolutas e interpicos encontrados no grupo de estudo foram menores do que os obtidos no grupo controle de forma significativa. Conclusão: a maturação do tronco encefálico nas crianças portadoras de infecção por Zika Vírus ocorreu dentro da normalidade. não apresentando alterações retrococleares até a idade de 5 anos.

Methodological approach for assessing motor cortical excitability changes with single-pulse transcranial magnetic stimulation.

Transcranial Magnetic Stimulation (TMS) serves as a crucial tool in evaluating motor cortex excitability by applying short magnetic pulses to the skull, inducing neuron depolarization in the cerebral cortex through electromagnetic induction. This technique leads to the activation of specific skeletal muscles recorded as Motor-Evoked Potentials (MEPs) through electromyography. Although various methodologies assess cortical excitability with TMS, measuring MEP amplitudes offers a straightforward approach, especially when comparing excitability states pre- and post-interventions designed to alter cortical excitability. Despite TMS's widespread use, the absence of a standardized procedure for such measurements in existing literature hinders the comparison of results across different studies. This paper proposes a standardized procedure for assessing changes in motor cortical excitability using single-pulse TMS pre- and post-intervention. The recommended approach utilizes an intensity equating to half of the MEP's maximum amplitude, thereby ensuring equal likelihood of amplitude increase or decrease, providing a consistent basis for future studies and facilitating meaningful comparisons of results.•A method for assessing changes in motor cortical excitability using single-pulse TMS before and after a specified intervention.•We recommend using an intensity equal to half of the MEP's maximum amplitude during evaluations to objectively assess motor cortical excitability changes post-intervention.

Does the Number of Stimuli Influence the Formation of the Endogenous Components of the Event-Related Auditory Evoked Potentials?

Introduction The number of stimuli is important to determine the quality of auditory evoked potential records. However, there is no consensus on that number in studies, especially in the sample studied. Objectives To investigate the influence of the number of rare stimuli on forming N2 and P3 components, with different types of acoustic stimuli. Methods Cross-sectional, descriptive, comparative study, approved by the ethics committee of the institution. The sample comprised 20 normal hearing adults of both sexes, aged 18 to 29 years old, with normal scores in the mental state examination and auditory processing skills. The event-related auditory evoked potentials were performed with nonverbal (1 kHz versus 2 kHz) and verbal stimuli (/BA/ versus /DA/). The number of rare stimuli varied randomly in the recordings, with 10, 20, 30, 40, and 50 presentations. Results P3 latency was significantly higher for nonverbal stimuli with 50 rare stimuli. N2 latency did not show any difference between the type and number of stimuli. The absolute P3 and N2-P3 amplitudes showed significant differences for both types of stimuli, with higher amplitude for 10 rare stimuli, in contrast with the other ones. The linear tendency test indicated significance only for the amplitude - as the number of rare stimuli increased, the amplitude tended to decrease. Conclusion The components were identifiable in the different numbers of rare stimuli and types of stimuli. The P3 and N2-P3 latency and amplitude increased with fewer verbal and nonverbal stimuli. Recording protocols must consider the number of rare stimuli.

Auditory Pathway Maturation in Full-term Small for Gestational Age Children: A Systematic Review with Meta-analysis.

Introduction Factors of intrauterine growth restriction have been responsible for the births of full-term babies small for their gestational age (SGA). Scientific evidence points that this restriction can cause changes in the neural maturation process. Objectives To analyze the absolute latencies and interpeak intervals of brainstem auditory evoked potential waves in full-term and SGA children to investigate whether there are changes of neural maturation in this population. Data Synthesis The search for articles that reported the assessment of brainstem auditory evoked potential in SGA newborns compared with a control, appropriate for their gestational age, both born full-term, for the entire period available in the database research until October 31, 2021 was performed based on the MEDLINE/PubMed Central and on the Latin America and the Caribbean Health Sciences Literature and Virtual Health Library electronic databases. A total of 311 studies were found in the database research. Out of this total, 10 studies were included in the review, 5 of which were eligible for the meta-analysis, involving a total of 473 participants of both genders, with 193 participants belonging to the study group and 280 to the control group. Differences between the groups were only observed in the absolute latency of wave V (95% confidence interval [CI]: 0.02-0.15; p < 0.01). Conclusion The SGA condition is responsible for the appearance of brainstem neural conduction dysfunction measured by the brainstem auditory evoked potentials, probably by the maturation process of the auditory pathway of this population.

Stroke in children and adolescents: Analysis of electrophysiological and behavioral assessment findings of auditory processing.

PURPOSE: This study aimed to analyze the auditory processing behavior of children and adolescents diagnosed with stroke and compare it with that of typically developing individuals. METHODS: This was an analytical cross-sectional study involving 48 participants aged between 7 and 17 years with adequate schooling for age and grade, allocated equally to two groups: Stroke (SG) and Control Groups (CG). For the SG, cases identified between 2003 and 2018 were considered. In the CG, school-aged participants with typical development were randomized. After screening for differential audiological assessment and confirmation of auditory pathway integrity at the brainstem level, binaural analyses of the auditory processing behavior were conducted using the Dichotic Digit Test (DDT), Frequency Pattern Test (FPT), and electrophysiological assessment (P300). The Shapiro-Wilk test for normality was conducted, followed by the T and Mann-Whitney tests, with a 95 % confidence level and significance offset at p < 0.05, using the SPSS software (IBM®, v. 22.) RESULTS: The CG performed better in terms of auditory processing. These differences were significant (p < 0.0001) for the binaural integration of DDT, FPT humming and Labeling, and P300 latency. The P300 results were similar; however, with a greater amplitude in the SG. CONCLUSION: This study showed that children and adolescents with stroke performed worse in electrophysiological and behavioral tests of auditory processing assessed using the auditory evoked potentials. These data reinforce the hypothesis that stroke-related lesions compromise the neural mechanisms underlying auditory processing.

Potenciales evocados auditivos de tronco en neonatos nacidos a gran altitud / Brainstem auditory evoked potentials in newborn infants born in a high-altitude area

Introducción. Una forma no invasiva y segura de evaluar los parámetros neurofisiológicos en recién nacidos es la evaluación de los potenciales evocados auditivos del tronco encefálico (PEAT). Objetivo. Evaluar las latencias e intervalos de ondas de los PEAT en neonatos sanos nacidos a gran altitud (Cusco, 3399 msnm). Población y métodos. Estudio transversal y prospectivo. Se incluyeron neonatos menores a 14 días de vida, dados de alta a menos de 7 días de nacidos, evaluados para determinar los valores de los PEAT a intensidades sonoras de 70 dB, 80 dB y 90 dB. Se incluyeron las variables edad gestacional, peso al nacer, tipo de parto. Se calcularon las diferencias de las medianas de las latencias e intervalos de las ondas según edad gestacional y peso al nacer. Resultados. Se evaluaron 96 neonatos (17 pretérminos). Las medianas de las latencias de las ondas I a V a 90 dB fueron las siguientes: onda I 1,56 ms; onda II 2,74 ms; onda III 4,37 ms; onda IV 5,62 ms, onda V 6,63 ms. La latencia de la onda I para 80 dB fue de 1,71 ms y para 70 dB de 1,88 ms. Los intervalos para las ondas (I-III), (III-V) y (I-V) fueron de 2,8 ms, 2,2 ms y 5,0 ms respectivamente, sin diferencias entre intensidades (p >0,05). La prematuridad y el bajo peso estuvieron asociados a latencias de la onda I más prolongadas (p <0,05). Conclusiones. Se presentan valores ajustados de latencias e intervalos de los PEAT en neonatos nacidos a gran altitud. Se identificó que, a distintas intensidades sonoras, se ven diferencias en las latencias de las ondas, pero no en los intervalos entre ondas.

Introduction. A non-invasive and safe way to assess neurophysiological parameters in newborn infants is the evaluation of brainstem auditory evoked potentials (BAEPs). Objective. To assess the latencies and wave intervals of BAEPs in healthy newborn infants born in a high-altitude area (Cusco, 3399 MASL). Population and methods. Cross-sectional and prospective study. Newborn infants younger than 14 days of age, discharged less than 7 days after birth, were assessed to determine BAEP values at intensities of 70 dB, 80 dB, and 90 dB. The study variables were gestational age, birth weight, and type of delivery. The median differences in wave latencies and intervals were estimated according to gestational age and birth weight. Results. A total of 96 newborn infants (17 preterm infants) were assessed. The median latencies of waves I­V at 90 dB were for wave I: 1.56 ms, wave II: 2,74 ms, wave III: 4.37 ms, wave IV: 5.62 ms, and wave V: 6.63 ms. The latency of wave I for 80 dB was 1.71 ms and for 70 dB, 1.88 ms. Wave intervals (I­III, III­V, I­V) were 2.8 ms, 2.2 ms, and 5.0 ms, respectively, without differences among intensities (p > 0.05). Prematurity and low birth weight were associated with a longer wave I latency (p < 0.05). Conclusions. Here we describe adjusted BAEP latency and interval values for newborn infants born at high altitude. At different sound intensities, we identified differences in wave latencies, but not in interwave intervals.

Utilização do Potencial Auditivo de Estado Estável em lactentes com baixo risco para perda auditiva / Use of Auditory Steady State Response in infants at low risk for hearing loss / Uso del potencial auditivo de estado estacionario en bebés con bajo riesgo de pérdida auditiva

Introdução: Com base na necessidade do diagnóstico audiológico e da intervenção precoce na vida de uma criança com perda auditiva, faz-se necessário a elaboração de protocolos de avaliação auditiva que forneçam o maior número de informações. Objetivo: Analisar um programa de saúde auditiva infantil com relação à adesão à triagem auditiva e procedimentos de diagnóstico. Metodologia: Pesquisa de caráter transversal com análise quantitativa. Realizado em três etapas: 1ª etapa: triagem auditiva de neonatos de alojamento conjunto; 2ª etapa: reteste das falhas; 3ª etapa: diagnóstico audiológico dos lactentes que falharam nas etapas anteriores com a utilização do Potencial Evocado Auditivo de Estado Estável (PEAEE) em conjunto com o Potencial Evocado Auditivo de Tronco Encefálico (PEATE). Resultados: Em 2019, 1.898 neonatos foram triados e destes, 287 (15.2%) falharam na primeira testagem em pelo menos uma orelha. Um total de 197 (10.3%) foram retestados e 14 (0,73%) falharam em pelo menos uma orelha. Dez (0,52%) neonatos retornaram para diagnóstico compondo uma amostra homogênea de neonatos nascidos a termo. Um neonato apresentou perda auditiva unilateral. O tempo necessário para coleta de dados no PEAEE foi de 20 minutos. Conclusão: O PEAEE pode ser considerado uma alternativa a ser utilizado na bateria de testes na avaliação audiológica infantil, juntamente com outros procedimentos, utilizando-se do princípio de verificação cruzada e adicionando uma informação valiosa, especialmente com relação às baixas frequências. (AU)

Introduction: Based on the need for audiological diagnosis and intervention as soon as possible in the life of a child with hearing loss, it is necessary to elaborate of hearing evaluation protocols with high efficiency, which provide the greatest amount of information. Aim: To analyze a pediatric hearing health program regarding their adherence to hearing screening, failure rates, and diagnostic procedures. Method: This is a cross-sectional, descriptive, quantitative study, and consisted of tree stages: Performed in three steps: 1st step: hearing screening of rooming-in neonates; 2nd stage: retest of failures; 3rd stage: audiological diagnosis of infants who failed in the previous stages using the Steady State Response (ASSR) together with the Brainstem Evoked Response Audiometry (BERA). Results: In 2019, 1,898 infants were submitted to the program, of whom 287 (15.2%) failed the screening in at least one of the ears. A total of 197 (10.3%) infants attended the retest and 14 (0.73%) failed the TOAE in at least one of the ears. Ten (0.52%) infants returned for diagnosis. The sample was homogeneously full-term children. One child showed unilateral HL. The average amount of time required to collect information in the ASSR was 20 minutes. Conclusion: For diagnosis, ASSR can be an alternative to be used in the battery of examinations in pediatric hearing assessment along with the other procedures, using the cross-check principle and adding valuable information, especially regarding the low frequencies. (AU)

Introducción: En base a la necesidad de diagnóstico audiológico e intervención lo antes posibles en la vida de un niño con pérdida auditiva, es necesario elaborar protocolos de evaluación auditiva de alta eficiencia, que proporcionan la mayor cantidad de información. Objetivo: Analizar un programa de salud auditiva infantil en cuanto a la adherencia al tamizaje auditivo, tasa de fracaso y procedimientos diagnósticos. Metodología: Investigación transversal con análisis cuantitativo, Realizado en tres pasos: 1er paso: tamizaje auditivo de los neonatos en alojamiento conjunto; 2ª etapa: retest de fallas; 3ª etapa: diagnóstico audiológico de los lactantes que fracasaron en las etapas anteriores utilizando el Potencial Evocado Auditivo de Estado Estacionario junto con el Potencial Evocado Auditivo de Tallo Cerebral. Resultados: Em 2019, se cribaron 1,898 neonatos y de estos, 287 (15,2%) no pasaron la primera prueba en al menos un oído. Un total de 197 (10,3) fueron reevaluados y 14 (0,73%) fallaron en al menos un oído. Diez (0,52%) neonatos regresaron para diagnóstico, conformando una muestra homogénea de neonatos a término, con una edad gestacional media de 39 semanas y dos días. Un neonato tuvo pérdida auditiva unilateral. El tiempo de recogida de los resultados en el ASSR fue de 20 min. Conclusión: Para el diagnóstico, la ASSR puede considerarse una alternativa para ser utilizada en la batería de pruebas en la evaluación audiológica infantil, junto con otros procedimientos, utilizando el principio de verificación cruzada y agregando información valiosa, especialmente en lo que se refiere a las bajas frecuencia. (AU)

Asymmetry of Occupational Noise Induced Hearing Loss: An Electrophysiological Approach

Abstract Introduction The question as to whether occupational noise exposure causes symmetrical or asymmetrical hearing loss is still controversial and incompletely understood. Objective Two electrophysiological methods (cortical evoked response audiometry: CERA and auditory steady state responses: ASSR) were used to address this issue. Method 156 subjects with a well-documented history of noise exposure, a wide range of noise induced hearing loss (NIHL) and without middle ear pathology underwent both a CERA and an ASSR examination in the context of an exhaustive medicolegal expert assessment intended for possible compensation. Results Whatever the method (CERA or ASSR), the average electrophysiological hearing thresholds (1-2-3 kHz) are significantly worse in the left ear. The right - left differences in CERA and ASSR thresholds are strongly correlated with each other. No significant effect of frequency is found. No correlation is observed between right - left differences in hearing thresholds and either age or degree of hearing loss. Conclusion In NIHL, there is an actual average right - left difference of about 2.23 dB, i.e., 3.2%, the left ear being more impaired.

Asymmetry of Occupational Noise Induced Hearing Loss: An Electrophysiological Approach.

Introduction The question as to whether occupational noise exposure causes symmetrical or asymmetrical hearing loss is still controversial and incompletely understood. Objective Two electrophysiological methods (cortical evoked response audiometry: CERA and auditory steady state responses: ASSR) were used to address this issue. Method 156 subjects with a well-documented history of noise exposure, a wide range of noise induced hearing loss (NIHL) and without middle ear pathology underwent both a CERA and an ASSR examination in the context of an exhaustive medicolegal expert assessment intended for possible compensation. Results Whatever the method (CERA or ASSR), the average electrophysiological hearing thresholds (1-2-3 kHz) are significantly worse in the left ear. The right - left differences in CERA and ASSR thresholds are strongly correlated with each other. No significant effect of frequency is found. No correlation is observed between right - left differences in hearing thresholds and either age or degree of hearing loss. Conclusion In NIHL, there is an actual average right - left difference of about 2.23 dB, i.e., 3.2%, the left ear being more impaired.