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.

The Effect of Different Stimulation Rates on Brainstem Auditory-Evoked-Potential Responses

Introduction  Auditory-evoked potentials are influenced by several factors, including polarity, filter, stimulus intensity and stimulation rate. The presentation of higher rates of stimuli per second enables the collection of a greater number of responses in a given period of time, promoting a shorter testing time; however, the collected recordings are subject to changes related to wave morphology. Objectives  To compare the brainstem auditory-evoked-potential responses with click stimulus with the most commonly used stimulation rates in the clinical practice. Methods  The present cross-sectional analytical study was performed with fifteen participants of both genders and normal hearing thresholds. The brainstem auditory-evoked potential was performed at four different stimulation rates (21.1, 26.7, and 27.7 stimuli/s, and a rate determined based on a mathematical calculation using the a measurement of the transmission frequency of the power grid at the time of the examination). Results  We observed that the rate of 21.1 stimuli/s showed the highest amplitudes for waves I, III, and V when compared with the other rates. The rate of 26.7 stimuli/s, when compared with 27.7 stimuli/s, showed a higher amplitude for wave V. The latency if wave V was significantly lower with the rate of 21.1 stimuli/s than with 27.7 stimuli/s. Conclusions  The stimulation rate interferes with wave latencies and amplitudes; its decrease from 27.7 to 21.1 stimuli/s decreases the latency of wave V and increases the amplitues and improves the morphology of waves I, III and V. In addition, we found evidence that suggests an improvement in the visualization of wave III by adjusting the stimulation rate based on a measurement of the local transmission frequency of the power grid.

Changes in cortical auditory evoked potentials in response to auditory training in elderly hearing aid users: A pilot study

OBJECTIVE

To compare the cortical auditory evoked potential responses pre-and post-Auditory Musical Training associated with hearing aid adaptation in elderly people with presbycusis.

DESIGN

This is a pilot, prospective, randomized, single-blind study.

STUDY SAMPLE

Eight presbiacusis elderly people between 65 and 80 years, new hearing aid users, divided into two groups participated in the study: Hearing Aid Group: use of hearing aid; and Auditory Training Group: use of hearing aid in addition to musical auditory training for 16 sessions. All participants were submitted to cortical auditory evoked potential tests with verbal stimulation in two different moments: Initial assessment, carried out before hearing aid adaptation and auditory training, and after three months, final assessment at the end of the auditory training sessions. All participants were adapted bilaterally with digital mini hearing aids.

RESULTS

There was a decrease in the P3a latency component for the Auditory Training Group when initial and final assessment were compared.

CONCLUSION

There was a change in the cortical auditory evoked potential in elderly people with presbycusis in response to the Musical Auditory Training associated with the use of hearing aids in elderly people with presbycusis.

Cognitive performance and long-latency auditory evoked potentials: a study on aging

OBJECTIVE

To evaluate the relationship between cognitive performance and long-latency auditory evoked potentials in an elderly population.

METHODS

The sample consisted of adults between 20 and 58 years of age and elderly adults between 60 and 70 years of age. The screening procedures adopted were an inspection of the external auditory canal, tonal and vocal audiometry, tympanometry, brain stem auditory evoked potential, the Montreal Cognitive Assessment test, and long-latency auditory evoked potential.

RESULTS

The latency and amplitude values of cortical components by age group showed significant differences under the following conditions: (i) signals evoked by the speech stimulus /da/ and by the pure-tone stimulus at 2,000 Hz for the N2 amplitude (p=0.008 and p=0.001, respectively) , which were both higher for adults, and (ii) signals evoked by the speech stimulus /da/ for N1 latency (p=0.018) and by the pure-tone stimulus at 2,000 Hz for P2 latency (p=0.017), which were both higher in the elderly population. The cognitive component (P300) showed a significant difference when evoked by speech stimuli, with higher latency in the elderly population (p=0.013). When correlated with cognitive processes, the latency and amplitude of cortical potentials showed direct and medium-strength correlations between abnormal scores obtained on the Montreal Cognitive Assessment test and P2 amplitude (p<0.001 and r=0.452).

CONCLUSION

There is a relationship between long-latency potentials and cognitive performance in the elderly, which was observed by the increase in the P2 amplitude and the impairment of the process of sound decoding.

Olfactory and taste disorders in COVID-19: a systematic review

Introduction

The SARS-CoV-2 virus causes COVID-19, and it is responsible for the largest pandemic since the 1918 H1N1 influenza outbreak. The classic symptoms of the disease have been well defined by the World Health Organization; however, olfactory/gustatory disorders have been reported in some studies, but there are still several missing points in the understanding and in the consensus about the clinical management of these cases.

Objective

To identify evidence in the scientific literature about olfactory/gustatory disorders, their clinical presentation, prevalence and possible specific treatments associated with COVID-19.

Methods

A systematic review of articles published up to April 25, 2020 was performed in Medline, Cochrane Clinical Trials, ScienceDirect, Lilacs, Scopus and Google Schoolar, OpenGrey.eu, DissOnline, The New York Academy of Medicine and Reasearch Gate. Inclusion criteria: (1) Studies on patients with COVID-19; (2) Records of COVID-19 signs/symptoms, and olfactory/gustatory functions. Exclusion criteria: (1) Studies on non-human coronavirus; (2) Review articles; (3) Experimental studies (in animals or in vitro); (4) Olfactory/gustatory disorders initiated prior to SARS-CoV-2 infection. The risk assessment of bias of the selected studies was performed using the Newcastle-Ottawa scale.

Results

Six articles from the 1788 records met the inclusion criteria and were analyzed. A total of 1457 patients of different ethnicities were assessed; of them, 885 (60.7%) and 822 (56.4%) had smell and taste disorders, respectively, with women being most often affected. There were olfactory/gustatory disorders even without nasal obstruction/rhinorrhea and beginning even before the signs/symptoms of COVID-19; the recovery of smell/taste, when it occurs, usually happened in the first two weeks after COVID-19 resolution. There is evidence that olfactory/gustatory disorders are strong predictors of infection by SARS-CoV-2, and it is possible to recommend patient isolation, as early as of the medical consultation, preventing the spread of the virus. No scientific evidence has been identified for effective treatments for any of the disorders.

Conclusion

Olfactory/gustatory disorders may occur at varying intensities and prior to the general symptoms of COVID-19 and should be considered as part of the clinical features of COVID-19, even in mild cases. There is still no scientific evidence of specific treatments for such disorders in COVID-19 disease.

Vestibular evoked myogenic potentials (VEMP) captured in the forearm flexor muscles: a study of its feasibility and reference ranges

OBJECTIVE

To determine the central tendency measures and variability of vestibular evoked myogenic potential (VEMP) with regard to the latency and wave amplitude when potentials are captured from the flexor muscles of the forearm.

METHODS

Ten adult volunteers with normal hearing underwent examination of their forearm flexor muscles (right and left sides; 20 samples in total) for VEMP acquisition. To this end, 200 tone burst stimuli at a 500 Hz frequency and 95 dBnHL intensity were promediated.

RESULTS

No statistical differences were observed in VEMP responses acquired from the right and left forearm flexor muscles concerning P34 and N44 latencies (p=0.32 and 0.90, respectively). The mean latency obtained for the P34 wave component was 34.9 ms (±2.6), with a lower limit equal to 29.3 and an upper limit equal to 40.4 ms. The average latency of the N44 wave component was 43.6 ms (±2.1), with a lower limit of 39.1 ms and an upper limit of 48.1 ms. The results were consistent and had low variability, and showed an average asymmetry index of 15.4 (±10.7). These findings indicate that potentials may be investigated in different age groups and in specific clinical populations, such as pathologies that may alter the neuronal transmission of the inferior vestibular pathway, especially when a longer portion is observed.

CONCLUSIONS

VEMP recording from forearm flexors is both feasible and stable, with latency reference ranges between 29.3 and 40.4 ms for P34, and 39.1 and 48.1 ms for N44.

The Value of Electrically Evoked Stapedius Reflex in Determining the Maximum Comfort Level of a Cochlear Implant

BACKGROUND

One of the most important steps for good user performance with a cochlear implant (CI) is activation and programming, aimed at determining the dynamic range. In adults, current levels are determined by psychophysical measures. In babies, small children, or individuals with multiple disorders, this procedure requires techniques that may provide inconsistent responses because of auditory inexperience or the age of the child, making it a very difficult process that demands the collaboration of both the patient and the family.

PURPOSE

To study the relationship between the electrically evoked stapedius reflex threshold (ESRT) and maximum comfort level for stimulating electrodes (C-level) in postoperative CI users.

RESEARCH DESIGN

Cross-sectional analytical observational case series study.

STUDY SAMPLE

We assessed 24 patients of both sexes, aged between 18 and 68 yr, submitted to CI surgery.

INTERVENTION

Otoscopy and immittance. Next, an implant speech processor connected to an Itautec^® computer containing the manufacturer's software (custom sound Ep 3-2) was used, as well as an AT 235h probe inserted into the ear contralateral to the CI to capture the stapedius reflex, obtaining electrically evoked stapedius reflex thresholds.

DATA COLLECTION AND ANALYSIS

Data from the last programming, defining C-levels for each electrode studied, were extracted from the databank of each patient. The manual decay function of the AT 235h middle ear analyzer was used to observe ESRT response in a same window for a longer response capture time. Electrodes 22, 16, 11, 6, and 1 were tested when active, with the aim of using electrodes over the entire length of the CI, and ESRT was considered present when compliance was ≥0.05 ml. Stimuli, in current units, were always initiated at 20 cu above the C-level. The analysis of variance parametric test, Tukey's honest significant difference test, the t-test, Wilcoxon nonparametric test, and the Kolmogorov-Smirnov test examined whether significant relationships existed between these other factors.

RESULTS

The results demonstrate that all the electrodes selected for the study exhibited higher mean reflex threshold values than their mean C-level counterparts. However, there was no significant difference between them, for electrodes 1, 6, 11, and 16. The data provided allow the use of ESRT to define C-level values and make it possible to stipulate a correction factor ranging between 6 and 25.6 electrical units.

CONCLUSION

The use of electrically evoked stapedius reflex thresholds can help the team in charge of programming CIs, making the process faster and safer, mainly for infants, small children, or individuals with multiple disorders.

Aging and wave-component latency delays in oVEMP and cVEMP: a systematic review with meta-analysis

INTRODUCTION

The natural aging process may result in morphological changes in the vestibular system and in the afferent neural pathway, including loss of hair cells, decreased numbers of vestibular nerve cells, and loss of neurons in the vestibular nucleus. Thus, with advancing age, there should be a decrease in amplitudes and an increase in latencies of the vestibular evoked myogenic potentials, especially the prolongation of p13 latency. Moreover, many investigations have found no significant differences in latencies with advancing age.

OBJECTIVE

To determine if there are significant differences in the latencies of cervical and ocular evoked myogenic potentials between elderly and adult patients.

METHODS

This is a systematic review with meta-analysis of observational studies, comparing the differences of these parameters between elderly and young adults, without language or date restrictions, in the following databases: Pubmed, ScienceDirect, SCOPUS, Web of Science, SciELO and LILACS, in addition to the gray literature databases: OpenGrey.eu and DissOnline, as well as Research Gate.

RESULTS

The n1 oVEMP latencies had a mean delay in the elderly of 2.32ms with 95% CI of 0.55-4.10ms. The overall effect test showed p=0.01, disclosing that such difference was significant. The heterogeneity found was I²=96% (p<0.001). Evaluation of p1 latency was not possible due to the low number of articles selected for this condition. cVEMP analysis was performed in 13 articles. For the p13 component, the mean latency delay in the elderly was 1.34ms with 95% CI of 0.56-2.11ms. The overall effect test showed a p<0.001, with heterogeneity value I²=92% (p<0.001). For the n23 component, the mean latency delay for the elderly was 2.82ms with 95% CI of 0.33-5.30ms. The overall effect test showed p=0.03. The heterogeneity found was I²=99% (p<0.001).

CONCLUSION

The latency of oVEMP n1 wave component and latencies of cVEMP p13 and n23 wave components are longer in the elderly aged >60 years than in young adults.

Study of cochlear microphonic potentials in auditory neuropathy

Introduction

Auditory Neuropathy/Dyssynchrony is a disorder characterized by the presence of Otoacoustic Emissions and Cochlear Microphonic Potentials, an absence or severe alteration of Brainstem Evoked Auditory Potential, auditory thresholds incompatible with speech thresholds and altered acoustic reflexes. The study of the Cochlear Microphonic Potential appears to be the most important tool for an accurate diagnosis of this pathology.

Objective

Determine the characteristics of the Cochlear Microphonic in Auditory Neuropathy/Dyssynchrony using an integrative review.

Methods

Bibliographic survey of Pubmed and Bireme platforms and MedLine, LILACS and SciELO data banks, with standardized searches up to July 2014, using keywords. Criteria were established for the selection and assessment of the scientific studies surveyed, considering the following aspects: author, year/place, degree of recommendation/level of scientific evidence, objective, sample, age range, mean age, tests, results and conclusion.

Results

Of the 1959 articles found, 1914 were excluded for the title, 20 for the abstract, 9 for the text of the article, 2 for being repeated and 14 were selected for the study.

Conclusion

The presence of the Cochlear Microphonic is a determining finding in the differential diagnosis of Auditory Neuropathy/Dyssynchrony. The protocol for the determination of Cochlear Microphonic must include the use of insert earphones, reverse polarity and blocking the stimulus tube to eliminate electrical artifact interference. The amplitude of the Cochlear Microphonic in Auditory Neuropathy/Dyssynchrony shows no significant difference from that of normal individuals. The duration of the Cochlear Microphonic is longer in individuals with Auditory Neuropathy/Dyssynchrony.

The importance of electrically evoked stapedial reflex in cochlear implant

Introdução

A determinação da área dinâmica do implante coclear é um dos procedimentos mais importantes em sua programação. O uso de medidas objetivas, em especial a do limiar do reflexo estapédico evocado eletricamente, pode contribuir para a definição deste campo, principalmente em crianças ou em indivíduos com múltiplos comprometimentos, pois fornecem valores específicos que servem como base no início da programação do implante coclear.

Objetivo

Verificar por meio de uma revisão a utilização do limiar do reflexo estapédico evocado ele- tricamente durante o processo de ativação e de mapeamento do implante coclear. Métodos: Levantamento bibliográfico nas plataformas Pubmed e Bireme e nas bases de dados MedLine, LILACS e SciELO, com buscas padronizadas até setembro de 2012, utilizando-se palavras-chave. Para a seleção e avaliação dos estudos científicos levantados, foram estabelecidos critérios, contemplando os seguintes aspectos: autor, ano/local, grau de recomendação/nível de evidência científica, objetivo, amostra, faixa etária, média de idade em anos, testes avaliativos, resultados e conclusão.

Resultados

Dos 7.304 artigos encontrados, 7.080 foram excluídos pelo título, 152 pelo resumo, 17 pela leitura do artigo, 43 eram repetidos e 12 foram selecionados para o estudo. Conclusão: O reflexo estapédico evocado eletricamente é capaz de auxiliar na programação do implante coclear, principalmente em pacientes que apresentam respostas inconsistentes.

© 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Publicado por Elsevier Editora Ltda. Todos os direitos reservados.

Sound localization and occupational noise

OBJECTIVE

The aim of this study was to determine the effects of occupational noise on sound localization in different spatial planes and frequencies among normal hearing firefighters.

METHOD

A total of 29 adults with pure-tone hearing thresholds below 25 dB took part in the study. The participants were divided into a group of 19 firefighters exposed to occupational noise and a control group of 10 adults who were not exposed to such noise. All subjects were assigned a sound localization task involving 117 stimuli from 13 sound sources that were spatially distributed in horizontal, vertical, midsagittal and transverse planes. The three stimuli, which were square waves with fundamental frequencies of 500, 2,000 and 4,000 Hz, were presented at a sound level of 70 dB and were randomly repeated three times from each sound source. The angle between the speaker's axis in the same plane was 45°, and the distance to the subject was 1 m.

RESULT

The results demonstrate that the sound localization ability of the firefighters was significantly lower (p<0.01) than that of the control group.

CONCLUSION

Exposure to occupational noise, even when not resulting in hearing loss, may lead to a diminished ability to locate a sound source.

The impact of stimulation rates in vestibular evoked myogenic potential testing

Vestibular evoked myogenic potentials (VEMP) have been used in complementary otoneurological assessment, but the use of VEMP in clinical settings is limited. VEMPs can be used to assess vestibular function, particularly of the saccule, the inferior vestibular nerve, and/or the vestibular nucleus.

Objective

To verify the highest possible - and reliable - stimulation rate to obtain VEMPs.

Method

The VEMPs of 18 subjects were acquired using stimulation rates ranging between 5.1 and 40.8 stimuli per second. Study design: cross-sectional contemporary cohort study.

Results

Latencies were kept unaltered and amplitudes were progressively reduced as stimulation rates were increased. However, ANOVA and the Kruskal-Wallis test failed to find statistically significant differences between the tested parameters. The study further indicated that when stimulation rates of 5.1 and 10.2 stimuli per second were compared, no statistically significant differences were observed in latency.

Conclusion

The highest reliable stimulation rate observed in the group of young adults with normal hearing included in this study was 10.2 stimuli per second.

Non-flat audiograms in sensorineural hearing loss and speech perception

OBJECTIVE

The audibility thresholds for the sound frequency of 137 upward- and downward-sloping audiograms showing sensorineural hearing loss were selected and analyzed in conjunction with speech recognition thresholds obtained from individuals seen at a public otolaryngology clinic to determine which frequencies in slope audiograms best represent speech recognition thresholds.

METHOD

The linear regression model and mean square error were used to determine the associations between the threshold values.

RESULT

The mean square error identified larger errors when using thresholds of 500, 1000, and 2000 Hz than when using audibility thresholds of 500, 1000, 2000, and 4000 Hz. The linear regression model showed a higher correlation (91%) between the audiogram thresholds for frequencies of 500, 1000, 2000, and 4000 Hz than for the frequencies of 500, 1000, and 2000 Hz (88%).

CONCLUSION

Frequencies of 500, 1000, 2000, and 4000 Hz were the most significant in predicting the speech recognition threshold.

Influence of gender on the vestibular evoked myogenic potential

There is no consensus on the relevance of factors that influence gender differences in the behavior of muscles. Some studies have reported a relationship between muscle tension and amplitude of the vestibular evoked myogenic potential; others, that results depend on which muscles are studied or on how much load is applied.

Aims

This study aims to compare vestibular evoked myogenic potential parameters between genders in young individuals.

Methods

Eighty young adults were selected - 40 men and 40 women. Stimuli were averaged tonebursts at 500 Hz, 90 dBHL intensity, and a 10-1000 Hz bandpass filter with amplification of 10-25 microvolts per division. The recordings were made in 80 ms windows.

Study type

An experimental and prospective study.

Results

No significant gender differences were found in wave latency - p = 0.19 and p = 0.50 for waves P13 and N23, respectively. No differences were found in amplitude values - p = 0.28 p = 0.40 for waves P13 and N23, respectively.

Conclusion

There were no gender differences in latency and amplitude factors; the sternocleidomastoid muscle strain was monitored during the examination.

Standardization of brainstem auditory evoked potential using a new device

BACKGROUND

Standardization of Brainstem Auditory Evoked Potential (BAEP) using a new device.

AIM

To standardize BAEP responses using a new device developed (NDD) in Brazil.

METHOD

Analysis of absolute latencies, interpeaks and wave amplitudes of BAEP, using a new device developed to study normal-hearing groups (91 adults) and individuals (15 adults) with bilateral neurosensory hearing loss. Responses obtained in the EP15 hearing device/Interacoustics and the NDD were compared. For this, the following paramenters were used: non-filtered click of 100 microsecond (µs), totaling 2000 stimuli in rarefied polarity, stimulation frequency of 13.1 clicks/s, intensity of 80 decibels normalized hearing level (dB nHL), with a window of 10 milliseconds and bandpass filter between 100 and 3000 Hertz (Hz). Significance level was set at 0.05.

RESULTS

Absolute latency and interpeak means for 76 normal-hearing individuals with the NDD were: wave I=1.50, III=3.57, V=5.53, I-III=2.06, III-V=1.96 and I-V=4.02. When analyzing results according to gender, there was a statistically significant difference for the absolute latencies of waves III and V and in interpeaks I-III and I-V. Mean amplitude value of wave I=0.384 microvolt (µV) and of wave V=0.825 µV. There was no statistically significant difference between the absolute latencies and interpeaks of the two devices in the same individual.

CONCLUSION

The components of BAEP with the NDD in normal-hearing subjects were similar regarding the tested ears, with statistically lower latencies in women. The BAEP latencies in the same individual with NDD were similar to those obtained with the EP15 / Interacoustics. Normal values of BAEP were obtained in normal-hearing adults.

Disfonia e disfunção temporomandibular: há relação?

OBJETIVO: verificar se existe relação entre disfonia e disfunção temporomandibular (DTM). MÉTODOS: este estudo foi realizado com 21 indivíduos, do gênero feminino, com faixa etária variando entre 18 - 27 anos, que não referiram sintomas de DTM, antes de serem apresentados ao questionário de triagem e, após o mesmo terem apresentado pelo menos um sintoma. Foram excluídos os indivíduos que não concordaram com o termo da pesquisa, não concluíram o protocolo de coleta de dados e os que apresentaram história de traumas e/ou cirurgia de face. A seleção dos sujeitos ocorreu de forma não probabilística por conveniência, utilizando-se pacientes que foram submetidos à triagem da Clínica Prof. Jurandir Bóia Rocha da Faculdade de Fonoaudiologia de Alagoas apresentando como queixa alterações vocais, levando em consideração os critérios de inclusão. Foram realizadas as seguintes avaliações: Fonoaudiológica (perceptivo-auditiva da Voz e específica para DTM) e Odontológica. Após os dados obtidos serem caracterizados com a utilização de técnicas de estatística descritiva, foi aplicado o Teste de correlação bivariada. Os cálculos foram obtidos através do software SPSS, na versão 16.0. RESULTADOS: dos indivíduos com DTM: 46,15% (N=6) apresentaram qualidade de voz soprosa; 30,76% (N=4) articulação travada; 23,07% (N=3) loudness reduzida e 23,07% (N=3) com ressonância alterada. CONCLUSÃO: não houve correlação entre alterações vocais e disfunção temporomandibular, provavelmente devido ao número reduzido de sujeitos avaliados.