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Background Multiple sclerosis (MS) is an inflammatory demyelinating disease. Auditory evoked potential studies have demonstrated conduction and neural processing deficits in adults with MS, but little is known about the electrophysiological responses in children and adolescents.

Background/Aim. In everyday communication, people are exposed to a myriad of sounds that need to be sorted and relevant information extracted. The ability of a person to concentrate on certain sounds in a noisy background environment, perform selective attention, and focus their auditory attention is crucial for everyday functioning and communication. The aim of this study was to investigate the effect of the sensorimotor rhythm (SMR) (12–15 Hz) neurofeedback (NFB) training to improve auditory cognition measured by the achievements in the Quick speech-in-noise (QuickSIN) test, changes in the amplitudes and latencies of components of auditory evoked potentials (AEP) N100, N200, and P300 in the auditory oddball discrimination task, and changes in the spectral power of the SMR. Methods. The study included 16 healthy participants aged 25–40 years (8 males and 8 females). Each participant had 20 daily sessions of SMR NFB training. Auditory cognitive functions and electrophysiological correlates of cognitive processing were recorded 5 times – before NFB, after 5, 10, and 20 sessions, and one month after the last session of NFB. Re-sults. The results showed a statistically significant decrease in N200 and P300 latencies at frontal midline (Fz), central midline (Cz), and parietal midline (Pz) regions, an improvement on the QuickSIN test, and an increase in electroencephalogram SMR rhythm spectral power in the Cz region as a result of the NFB SMR training. No significant effect of the NFB training on the N100, N200, and P300 amplitudes on Fz, Cz, and Pz was found. Conclusion. The obtained results suggest that SMR NFB affects auditory perception in terms of shorter latencies of AEP and better performance on the QuickSIN test.

Background/Aim. Neurofeedback (NFB) training of sensorimotor rhythm (SMR) contributes to improving cognitive performance and increasing attention. SMR power is increased when a person is focused and task-oriented. The shorter reaction time (RT) of the P300 auditory evoked potentials (AEPs) is associated with better attention. Hence, the increase in SMR power after NFB SMR training should decrease the RT in a cognitive task. The aim of the study was to examine the ability of healthy individuals to modulate the SMR of electroencephalographic (EEG) activity between 12 and 15 Hz during 20-day NFB training sessions. In addition, the effect of NFB SMR training on RT was investigated. Methods. Participants were divided into experimental and control groups, with 24 subjects (12 males and 12 females) in each group, aged between 25 and 40 years. Participants in the experimental group were trained with authentic NFB SMR training, while in the control group, false (placebo) training was applied. AEPs were registered on five occasions: before NFB training, after 5, 10, and 20 training sessions, and one month after the last training. Results. The results showed that a series of 20 NFB SMR training sessions increased the amplitudes of the SMR. RT in the experimental group was significantly shortened, while in the control group, it was not observed. Moreover, the increase in the power of the EEG signal o f t he S MR showed a negative correlation with RT, but only in a subgroup of male subjects. Conclusion. The obtained results indicate the effects of NFB training on the improvement of the attention process expressed by RT.

ABSTRACT Purpose: to compare the Auditory Middle Latency Response in adults, one group with and another group without altered auditory skills. In addition, the aim was to compare cut-off values of 30% and 50% for the Ear Effect in terms of sensitivity and specificity. Methods: the sample comprised 32 individuals of both genders with no hearing loss who were divided into Group 1 (16 individuals with no alterations in auditory skills) and Group 2 (16 individuals with alterations in auditory skills). All participants received an audiological evaluation and measurement of Brainstem and Auditory Middle Latency Potentials. Results: when Group 1 and Group 2 were compared, a statistically significant difference was only observed in Na and Pa amplitude of waves A1C3 and A2C3. In the analysis of sensitivity and specificity of the Auditory Middle Latency Response, a cut-off value of 50% gave a better balance between sensitivity and specificity. Conclusion: adults presented with altered auditory abilities had smaller response amplitudes in the Na and Pa components of the waves generated in the left hemisphere. A cut-off value of 50% gave a better discrimination of the Ear Effect for identifying subjects with altered auditory skills.

Background/Aim. Neurofeedback (NFB) is a therapeutic method based on monitoring the electroencephalogram (EEG) and providing feedback on the brain activity of sub-jects. The aim of the pilot study was to investigate the effect of lower-beta or sensorimotor rhythm (SMR) (12–15 Hz) NFB training on amplitudes and latencies of late auditory event-related potentials (aERP) components N100, N200, P300 in Go-No go task of auditory discrimination. Methods. Each of 9 healthy participants aged 25–40 years (4 male) had 20 daily sessions of SMR neurofeedback training. The aERP was recorded 5 times: before NFB, after 5, 10, and 20 sessions, and one m onth after the last session. Results. The results showed a statistically significant decrease in N100, N200, and P300 latencies at Fz, Cz, and Pz regions. No significant effect of NFB training on amplitudes of components N100, N200 and N300 was found. Conclusion. The obtained results suggest that NFB training exerts its effect on the processes of auditory cognition.

Introduction: Central auditory processing refers to the efficiency and effectiveness with which the central nervous system uses auditory information: it may be altered in neurological disorders and brain injuries, such as strokes. However, despite evidence of probable alterations in the pediatric population, functional abilities and post-stroke limitations are still not well documented in the literature. Objective: To analyze the findings of the electrophysiological and behavioral evaluations of central auditory processing of children and adolescents diagnosed with stroke from a reference outpatient clinic, as well as to investigate possible associations with the variables: type and location of the stroke and age group. Methods: The present study is characterized as comparative cross-sectional. The sample, for convenience, included individuals aged 7–18 years divided into two groups: study group, composed of individuals with a diagnosis of stroke, and control group, composed of individuals with typical development. The evaluation consisted of the following procedures: anamnesis, basic audiological evaluation, behavioral evaluation of the auditory processing disorder (dichotic digit test, dichotic consonant-vowel, synthetic sentence identification/pediatric speech intelligibility, gaps in noise, pitch pattern sequence, masking level difference), and electrophysiological evaluation (P300 and mismatch negativity). Results: Nineteen children and adolescents were included in the study group. The control group was composed of 19 children and adolescents with typical development. In the comparison between the groups, a worse performance is observed for the study group in all the evaluated tests, behavioral and electrophysiological. In the behavioral evaluation of central auditory processing, there was a statistical difference for all tests, except for masking level difference and dichotic digit test, binaural separation step on the left. In the electrophysiological evaluation, there was a statistical difference in the latency of mismatch negativity and P300. No associations were found between the behavioral and electrophysiological findings and the location of the stroke and age group variables. Conclusion: Children and adolescents diagnosed with stroke present a worse performance in the electrophysiological and behavioral evaluations of central auditory processing when compared to a control group.

Introduction: Recent studies have shown that musical practice and training are effective and have the potential to assist in the acquisition and improvement of auditory skills. Objective: To verify the scientific evidence on the implications of musical practice in central auditory processing. Methods: A systematic review was carried out in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), using the Medline (Pubmed), LILACS, SciELO, BIREME, Scopus and Web of Science databases. The search period for the articles covered the last 5 years (2015–2020), without restriction of language and location. The quality of the articles was assessed, and the review included articles with a minimum score of 6 in a modified literature quality scale. Results: Initially, 1362 publications were found, of which 1338 were excluded after the title screening, 15 were excluded due to the abstract, with nine articles being analyzed in full and four of them excluded after the analysis, as they did not answer the guiding question proposed for this research. Five articles that met the proposed inclusion criteria were admitted for this research. It was found that in adults, musical ability is associated with better performance of several auditory processing skills, as well as the fact that musical training in children promoted an accelerated maturity of auditory processing and exposure to music facilitated the learning of auditory information in newborns. Conclusion: Considering the scientific evidence, it was found that the musical experience can improve specific skills of the central auditory processing, regardless of age, optimizing children’s linguistic development.

ABSTRACT Objective To analyze age-related changes in the central auditory pathway in healthy elderly individuals. Methods A prospective, quantitative cross-sectional study. The caseload comprised 18 adults (mean age, 22.78 years) and 18 elderly individuals (mean age, 66.72 years) of both sexes, who met inclusion criteria. Subjects were submitted to basic audiological evaluation and related electrophysiologic tests: brainstem auditory evoked potential with click stimulus and frequency-following response. Results Elderly individuals had higher wave and interpeak latencies (waves I, III and V and interpeaks I-V and III-V) of brainstem auditory evoked potential. Latencies of frequency following response waves A, E, F and O were also higher in elderly individuals. Frequency following response amplitudes were better in A than in D, F and O waves in these subjects. Likewise, interpeak intervals (V-A and V-O) were larger in elderly relative to adult individuals. Lower slope values were observed in elderly individuals. Conclusion Brainstem auditory evoked potential and frequency-following response allowed appropriate assessment of age-related changes in the auditory pathway. Slower neural response to auditory stimuli suggests reduced synchrony between neural structures.

ABSTRACT Purpose: to monitor, with long-latency auditory evoked potentials, the plasticity of the central auditory pathways in adults and older adults, new users of hearing aids. Methods: a total of 15 adults and older adults, aged 55 to 85 years, participated in the research. They had a symmetric bilateral mild to moderate sensorineural hearing loss, without previous experience with any type of hearing aid. The long-latency auditory evoked potentials were conducted with and without amplification, at 60 and 75 dBnHL, with speech stimulus in a sound field, in two assessment moments: up to one week after fitting the hearing aid and after six months of its use. The Student’s t-test was used for statistical analysis, considering significant the p-value < 0.05. Results: responses with lower latency values were observed for the right ear in the second assessment. Comparing the first with the second assessment, both with and without the hearing aid, an increase in the amplitude of P2-N2 was observed, as well as an increase in the latency of the P2 component at the intensity of 75 dBnHL. No statistically significant differences were observed at the intensity of 60 dBnHL. Conclusion:the use of the hearing aid promoted the plasticity of the central auditory pathways, increasing the number of neurons responsive to the sound stimuli.

Objective The tests of three types of auditory evoked potentials （AEPs） were performed on normal young adults, to understand the frequency characteristics of different testing methods and the relationship between response threshold and pure tone audiometry threshold of different methods, and to discuss the forensic value of 3 types of AEPs to evaluate hearing function. Methods Twenty normal young adults were selected, their standard pure tone audiometry threshold, short-term pure tone audiometry threshold and the response threshold of 3 types of AEPs （tone burst-auditory brainstem response, 40 Hz auditory event-related potential and slow vertex response） at 0.5 kHz, 1.0 kHz, 2.0 kHz and 4.0 kHz were recorded. The relationship between the response threshold and standard pure tone audiometry threshold, short-term pure tone audiometry threshold of 3 types of AEPs at different frequencies as well as the differences between different types of AEPs were analyzed. Results The short-term pure tone audiometry threshold was higher than the standard pure tone audiometry threshold at each frequency. The response threshold and standard pure tone audiometry threshold of the 3 types of AEPs all had a certain correlation, and the response threshold of the 3 types of AEPs was higher than short-term pure tone audiometry threshold and standard pure tone audiometry threshold at each frequency. The differences in the differences between the response threshold and standard pure tone audiometry threshold of the 3 types of AEPs at different frequencies had statistical significance. Linear regression mathematical models were established to infer the standard pure tone audiometry threshold （hearing level） from response threshold （sound pressure level） of 3 types of AEPs of normal young adults. Conclusion When using response threshold of different types of AEPs to estimate pure tone audiometry threshold, conversion and correction are needed. Combined use of different types of AEPs could improve the accuracy of hearing function evaluation.

Abstract Introduction Studies using the Brainstem Auditory Evoked Potential with speech stimulus are increasing in Brazil, and there are divergences between the methodologies used for testing. Objectives To analyze the parameters used in the study of the Brainstem Auditory Evoked Potentials with speech stimulus. Data Synthesis The survey was performed using electronic databases. The search strategy was as follows: “Evoked potentials, auditory” OR “Brain stem” OR “Evoked potentials, auditory, brain stem” AND “Speech.” The survey was performed from June to July of 2016. The criteria used for including articles in this study were: being written in Portuguese, English or Spanish; presenting the description of the testing parameters and the description of the sample. In the databases selected, 2,384 articles were found, and 43 articles met all of the inclusion criteria. The predominance of the following parameters was observed to achieve the potential during study: stimulation with the syllable /da/; monaural presentation with greater use of the right ear; intensity of 80 dB SPL; vertical placement of electrodes; use of in-ear headphones; patient seated, distracted in awake state; alternating polarity; use of speech synthesizer software for the elaboration of stimuli; presentation rate of 10.9/s; and sampling rate of 20 kHz. Conclusions The theme addressed in this systematic review is relatively recent. However, the results are significant enough to encourage the use of the procedure in clinical practice and advise clinicians about the most used procedures in each parameter.

RESUMO Objetivo O objetivo desse estudo foi comparar a latência e amplitude do potencial evocado auditivo cortical P1i entre neonatos em estado de alerta e durante o sono leve. Métodos Vinte e cinco neonatos com emissões otoacústicas evocadas transientes presentes foram testados, por meio do potencial evocado auditivo cortical (PEAC), sendo dez em estado de alerta e 15 durante o sono leve. Para pesquisa dos potenciais corticais, utilizou-se o equipamento Hearlab System, de um canal, no módulo Cortical Tone Evaluation (CTE). O potencial P1i foi pesquisado de forma monoaural, na intensidade de 80 dBnNA, para as frequências de 500, 1000, 2000 e 4000Hz. A detecção do P1i foi feita de maneira automática pelo equipamento. A marcação da latência e amplitude foi realizada por três juízes. Resultados Não houve diferença estatisticamente significativa entre os dois grupos de neonatos para os valores de amplitude e latência, nas quatro frequências testadas. Conclusão Não houve influência do estado comportamental dos neonatos na avaliação do potencial cortical P1i.

OBJETIVO: Descrever os resultados das avaliações audiológica e eletrofisiológica da audição em pacientes portadores de ataxia espinocerebelar (AEC). MÉTODOS: Foi realizado um estudo retrospectivo de corte transversal no qual se avaliou 43 pacientes portadores de AEC submetidos aos seguintes procedimentos: anamnese e avaliações otorrinolaringológica, audiológica, imitanciométrica e do potencial evocado auditivo de tronco encefálico (PEATE). RESULTADOS: Os pacientes apresentaram prevalência do desequilíbrio à marcha (83,7%), dificuldade para falar (48,8%), tontura (41,8%) e disfagia (39,5%). A perda auditiva foi referida em 27,9% dos casos; no exame audiométrico, 14 pacientes (32,5%) apresentaram alterações; na AEC 3, 33,3%; na AEC 2, 12,5%; na AEC 4, 100,0%; na AEC 6, 100,0%; na AEC 7, 100,0%; na AEC 10, 50,0%; e na AEC indeterminada, 21,4%. No PEATE, 20 pacientes (46,5%) apresentaram alterações, sendo 58,3% na AEC 3, 62,5% na AEC 2, 100,0% na AEC 6, 100,0% na AEC 7, 66,7% na AEC 10 e 14,2% na AEC indeterminada. No exame imitanciométrico, 19 pacientes (44,1%) apresentaram alterações, sendo 50,0% na AEC 3, 50,0% na AEC 2, 100,0% na AEC 4, 100,0% na AEC 6, 100,0% na AEC 7, 33,3% na AEC 10 e 28,5% na AEC indeterminada. CONCLUSÃO: As alterações mais evidenciadas na avaliação audiológica foram o predomínio da configuração audiométrica descendente a partir da frequência de 4 kHz bilateralmente e a ausência do reflexo acústico nas frequências de 3 e 4 kHz bilateralmente. Na avaliação eletrofisiológica, 50% dos pacientes apresentaram alterações com prevalência do aumento das latências das ondas I, III e V e do intervalo nos interpicos I-III, I-V e III-V.

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OBJETIVO: Comparar as latências e as amplitudes da onda V no registro do Potencial Evocado Auditivo de Tronco Encefálico (PEATE) com os estímulos clique e CE-chirp® e a presença ou ausência das ondas I, III e V em fortes intensidades. MÉTODOS: Estudo transversal com 12 adultos com limiares audiométricos PURPOSE: To compare the latencies and amplitudes of wave V on the Brainstem Auditory Evoked Potential (BAEP) recording obtained with click and CE-chirp® stimuli and the presence or absence of waves I, III and V in high intensities. METHODS: Cross-sectional study with 12 adults with audiometric thresholds

RESUMO Objetivo Pesquisar os potenciais exógenos em neonatos normo-ouvintes, nascidos a termo e pré-termo, correlacionando-os ao gênero e presença de Indicadores de Risco para Deficiência Auditiva (IRDA). Métodos A amostra inicial foi composta por 127 neonatos e, após análise de juízes, foram considerados 96. Destes, 66 eram nascidos a termo e 30 nascidos pré-termo, em um hospital público. Todos os neonatos apresentaram resultado “passa” na triagem auditiva neonatal. Os registros do exame foram feitos com os neonatos em sono natural, por meio de eletrodos assim posicionados: o ativo na fronte (Fz), o terra (Fpz) na fronte e os de referência na mastoide esquerda (M1) e direita (M2). Foram apresentados estímulos verbais, binauralmente, sendo /ba/ o estímulo frequente e /ga/ o estímulo raro, em intensidade de 70 dBNA, por meio de fones de inserção. Respeitou-se o paradigma oddball. Foi analisada a presença ou ausência dos potenciais exógenos. Para análise dos dados foram utilizados os testes estatísticos. Resultados Houve diferença significativa nos valores dos componentes para o gênero feminino, relacionados à amplitude de N1-P2, na orelha esquerda. Não houve diferença entre presença de IRDAs e ausência de componentes. Conclusão Verificou-se que os Potenciais Evocados Auditivos Corticais em neonatos apresentaram valores maiores de amplitude no Grupo Pré-termo, no gênero feminino, e ausência de diferença quanto à latência. Quanto à presença de IRDAs e ausência de componentes, não foi encontrada relação.

OBJETIVO: verificar a utilização do estímulo ruído branco, modulado em amplitude, no exame de Potencial Evocado Auditivo de Estado Estável (PEAEE). MÉTODO: foram avaliados 30 neonatos e lactentes, na Maternidade do Hospital das Clínicas da UFPE, que realizaram os exames de Emissões Otoacústicas Transientes (EOAT) e PEAEE, com ruído branco de amplitude modulada. RESULTADOS: para o exame de PEAEE, sugere-se que a intensidade ideal para o ponto de corte seja 50 dB NPS, para os casos com passa na triagem auditiva, com o exame de EOAT. CONCLUSÃO: o exame de PEAEE, realizado com ruído branco, modulado em amplitude, parece ser promissor como ferramenta de triagem auditiva. Entretanto, estudos são necessários para observar a relação entre os limiares das respostas auditivas de estado estável utilizando-se tons puros e ruído branco, a fim de melhor elucidar e definir parâmetros e protocolos de sua utilização.PURPOSE: to check the use of amplitude modulated white noise as a stimulus for the auditory steady state response. METHOD: thirty neonates were evaluated with transient otoacoustic emissions and auditory steady state response, with amplitude modulate white noise, at the Clinical Hospital in the Federal University of Pernambuco. RESULTS: for the auditory steady state response, it is suggested that the cut point intensity related with normal hearing is 50 dB SPL, as it was related to the presence of transient otoacoustic emissions. CONCLUSION: the auditory steady state response, evoked with amplitude modulate white noise seems to be promissory as a tool for hearing screening. More studies need to be done in order to better establish the hearing threshold and to define more precise protocols for its employment.

Background/Aim. Nowadays development of techniques enables detection of hearing impairment in a very short time, immediately after birth by using otoacoustic emissions. They are low-pitched sounds produced in physiologically clear cochlea and can be recorded in cochlear outer meatus. By this method, complete data are found on a whole presynaptic auditory nervous system functioning that has mostly been affected by pathological changes making it a perfect screening test. Reliability and sensibility of this method is up to 98%. The aim of this study was to present the first results of systematic neonatal screening of hearing function by otoacoustic emissions in the Clinical Center Kragujevac (Kragujevac, Serbia). Methods. This prospective study of neonatal hearing screening function, initiated systematically by the 2008 at the Clinical Center Kragujevac, included full-term newborns and premature born ones, within the first 24 h after birth, using a DPOAEs interacoustics otoread-screener. Retesting was done after a month. Results. From January 1st, 2009 to December 1st, 2010, a total number of examined infants by this method was 1,994 out of which 1,778 were full-term and 216 were premature born. The test passing was higher in the group of full-term babies (92.5%) than in the preterm ones (55.1%). No bilateral answers were recorded in premature born children compared to the full-term ones, of whom a larger number was with missing lateral responses. The results of re-examination test in the group of full-term born and premature newborns were 83.7%, and 61%, respectively. Conclusion. Deliberately provoked transient otoacoustic emission is an efficient method in testing hearing function in newborns, since it is non-invasive, rapid and objective. Its correlation with audibly evoked potentials is very high, which confirms its reliability.

OBJETIVO: determinar os níveis mínimos de resposta (NMR) e a latência da onda V em lactentes ouvintes nas frequências de 0.5, 1, 2 e 4 kHz. MÉTODOS: foram avaliados 23 lactentes sem indicadores de risco para deficiência auditiva que apresentavam emissões otoacústicas evocadas por estímulo transiente (EOAET) e potenciais evocados auditivos de tronco encefálico automático (PEATE-A) presentes bilateralmente. RESULTADOS: obtiveram-se NMR médios de 34.2 dBnNA, 25.4 dBnNA, 19 dBnNA e 17.5 dBnNA para as frequências de 0.5, 1, 2 e 4 kHz, respectivamente. Os tempos médios de latência da onda V em 70 e 20 dBnNA, respectivamente, na frequência de 0.5 kHz foram de 10.75 ms e 15.2 ms, em 1 kHz de 8.9 ms e 13.4 ms; de 7.7 ms e 10.2 ms em 2 kHz, e para 4 kHz foram de 7.3 ms e 9.4 ms. CONCLUSÃO: os valores encontrados podem ser utilizados na prática clínica para orientar o diagnóstico diferencial da perda auditiva, complementando a avaliação auditiva de lactentes.PURPOSE: to determine the ABR thresholds and the latency of V wave in hearing infants at the frequencies: 0.5, 1, 2 and 4 kHz. METHODS: 23 infants with no risk factors concerning hearing loss that had transient otoacoustic emissions (TOAE) and automatic auditory brainstem response (A-ABR), bilaterally present, were evaluated. RESULTS: ABR thresholds were obtained in average, namely: 34.2 dBHL, 25.4 dBHL, 19 dBHL and 17.5 dBHL for frequencies of 0.5, 1, 2 and 4 kHz, respectively. The mean latency of V wave at 70 and 20 dBHL, respectively, at a 0.5 kHz frequency were 10.75 ms and 15.2 ms, 1 kHz 8.9 ms and 13.4 ms; 7.7 ms and 10.2 ms at 2 kHz, and as for4 kHz they were 7.3 ms and 9.4 ms. CONCLUSIONS: 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 infants.

OBJETIVO: Avaliar a estabilidade dos parâmetros dos potenciais evocados auditivos em adultos normais. MÉTODOS: Foram submetidos à avaliação audiológica e eletrofisiológica (potencial evocado auditivo de tronco encefálico - PEATE, potencial evocado auditivo de média latência - PEAML e potencial cognitivo - P300) 49 indivíduos normais, de 18 a 40 anos (25 do gênero feminino e 24 do gênero masculino). Realizou-se reavaliação três meses após a avaliação. RESULTADOS: Foram observadas diferenças entre os gêneros na avaliação para as latências das ondas III e V e interpicos I-III e I-V do PEATE e amplitude N2-P3 do P300. Não foram verificadas diferenças significativas para os parâmetros do PEATE, PEAML (latência das ondas Na, Pa e amplitude Na - Pa) e P300 (latência da onda P300) entre os resultados obtidos na avaliação e reavaliação. CONCLUSÃO: Exceção feita à amplitude N2-P3, observou-se estabilidade dos parâmetros de PEATE, PEAML e P300 em adultos normais após período de três meses.PURPOSE: To evaluate the stability of parameters of auditory evoked potentials in normal adults. METHODS: Forty-nine normal subjects with ages from 18 to 40 years (25 females and 24 males) were submitted to audiological and electrophysiological hearing evaluation (auditory brainstem response - ABR, middle latency response - MLR, and cognitive potential - P300). Subjects were reassessed three months after the initial evaluation. RESULTS: Significant differences were observed between genders regarding the wave latencies III and V and the interpeaks I-III and I-IV of ABR, and the amplitude N2-P3 of the P300. No differences were found between the results of initial and final assessments for the parameters of the ABR, MLR (Na, Pa latencies and Na-Pa amplitude) and P300 (P300 latency). CONCLUSION: Except for the N2-P3 amplitude, it was observed stability of the parameters of ABR, MLR and P300 in normal adults after a period of three months.

TEMA: a fenilcetonúria é uma doença genética que provoca alterações bioquímicas conduzindo a uma deficiência na síntese de proteínas e de neurotransmissores, e prejudicando o processo de mielinização. Mudanças estruturais e funcionais da mielina podem alterar os padrões de condutividade neuronal e ou diminuir a conexão sináptica em indivíduos com fenilcetonúria. Essencialmente, um tratamento dietético deve ser realizado dentro das primeiras semanas de vida para evitar as manifestações clínicas e bioquímicas da doença. Quando a dieta é mantida ininterruptamente, as crianças com fenilcetonúria apresentam desenvolvimento normal. Porém, foram observados déficits em funções executivas, na interação inter-hemisférica, na linguagem e memória mesmo em crianças com tratamento precoce e dieta adequada. Algumas pesquisas foram realizadas para investigação da relação entre fenilcetonúria e alterações auditivas. OBJETIVO: rever de forma sistemática os artigos científicos dedicados à pesquisa da relação entre alterações auditivas e hiperfenilalaninemias, destacando a fenilcetonúria clássica. As referências bibliográficas foram obtidas por meio de pesquisa nas bases de dados Lilacs, Medline, Biblioteca Cochrane e Scielo e por busca na lista de referência dos artigos identificados e selecionados. CONCLUSÃO: conclui-se que a relação entre hiperfenilalaninemias, incluindo a fenilcetonúria, e alterações auditivas ainda é controversa na literatura. Sugere-se a realização de mais investigações sobre a função auditiva nesses indivíduos a fim de elucidar essa possível relação.BACKGROUND: phenylketonuria is a genetic disorder that causes biochemical alterations, leading to a deficiency in the synthesis of proteins and neurotransmitters and thereby hindering the myelination process. Structural and functional changes in myelin can alter neural conductivity patterns and or reduce synaptic connection in individuals with phenylketonuria. Essentially, a dietary treatment should be implemented in the first weeks of life in order to avoid clinical and biochemical manifestations of the disease. When diet is continually maintained, children with phenylketonuria show normal development. However, deficits in executive functions, interhemispherical interaction, language and memory have been observed even in children with early treatment and appropriate diet. Some researches were carried out for investigating the relationship between phenylketonuria and alterations in the hearing function. PURPOSE: to systematically review articles dedicated to the research of relationship between hearing disorders and hyperphenylalaninaemias, highlighting the classic phenylketonuria. The bibliographical references were obtained through research in the databases: Lilacs, Medline, Cochrane Library and Scielo and through search in the reference list of the identified and selected articles. CONCLUSION: the relationship among hyperphenylalaninaemias, including phenylketonuria, and hearing alterations is still controversial in the literature. It is suggested that more investigations as for the hearing function are necessary on those individuals in order to elucidate this possible relationship.

Background/Aim. A more recent method, the auditory steadystate response (ASSR), has become more and more important test method due to difference that was found in previous investigations between hearing thresholds determined by the ASSR and the pure-tone audiometry (PTA). The aim of this study was to evaluate the reliability of the ASSR in determining the frequency specific hearing thresholds by establishing a correlation between the thresholds determined by PTA, as well as to evaluate the reliability of ASSR in determining the hearing threshold with respect to the level of hearing loss and the configuration of the PTA findings. Methods. The prospective study included 46 subjects (92 ears) which were assigned to groups based on their level of hearing loss and audiometric configuration. All the subjects underwent determination of hearing thresholds by PTA and ASSR without insight into their previously obtained PTA results. Results. The overall sample differences between the ASSR and PTA thresholds were 4.1, 2.5, 4.4, and 4.2 dB at 0.5, 1, 2, and 4 kHz, respectively. A high level of correlation was achieved in groups with different configurations of PTA findings. The correlation coefficients between the hearing thresholds determined by ASSR and PTA were significant in subjects with all levels of hearing loss. The differences between hearing thresholds determined by ASSR and PTA were less than 10 dB in 85% of subjects (ranging from 4 dB for moderately severe hearing loss to 7.2 dB for normal hearing). Conclusion. The ASSR is an excellent complementary method for the determination of hearing thresholds at the 4 carrier frequencies, as well as determination of the level of hearing loss and the audiometric configuration.

OBJETIVO: Comparar com a literatura os valores de latência e amplitude de P300 em adultos jovens brasileiros saudáveis a fim de estabelecer um padrão normativo para futuros estudos, e verificar se os valores encontrados na amostra possuem correlação com o sexo, situação proposta na metodologia do exame e fases do ciclo menstrual. MÉTODOS: A amostra constou de 22 indivíduos saudáveis, sem queixa de desatenção, sem problemas neurológicos e auditivos, de 18 a 30 anos de idade. Todos os indivíduos foram submetidos à avaliação audiológica básica a fim de excluir aqueles com perda de audição. As respostas do P300 foram obtidas com equipamento AMPLAID MK22, de dois canais e em ambiente silencioso. RESULTADOS: Os resultados de latência encontrados na amostra, depois de comparados à literatura, enquadraram-se melhor nos intervalos de latência entre 220 e 380 ms. Somente os valores de amplitude foram influenciados pelas variáveis sexo e fase do ciclo menstrual. CONCLUSÃO: Os valores de latência da amostra não sofreram influência da variável sexo, ciclo menstrual e situação, e aproximaram-se com mais fidedignidade aos valores de intervalos de latência entre 220 e 380 ms. Contudo, os intervalos para a amplitude sofreram influência das variáveis sexo e ciclo menstrual, mas não se enquadraram adequadamente aos valores de intervalo encontrados na literatura.PURPOSE: To compare the values of latency and amplitude of P300 of healthy Brazilian young adults with the data available on the literature, in order to establish a normative standard for future studies. In addition, the aim was also to verify if the values found in the sample were correlated to gender, situation proposed in the methodology of the examination, and phase of menstrual cycle. METHODS: The sample consisted of 22 healthy individuals, without any attention complaints, neurological or auditory disorders, and with ages ranging from 18 to 30 years. All subjects carried out basic audiological evaluation in order to exclude those with hearing loss. The P300 test was carried out in a quiet room, using the two channels equipment AMPLAID MK22. RESULTS: The latency values obtained in the sample, after compared with the literature reference, were in accordance with the latency intervals between 220 e 380 ms. Only amplitude values were influenced by gender and phase of the menstrual cycle. CONCLUSION: The latency values of the sample were not influenced by the variables gender, methodology of the testing situation and menstrual cycle, and were in accordance to the latency interval values between 220 and 380 ms. Amplitude values were influenced by gender and menstrual cycle, but were not in accordance to the values found in literature.

To better understand sensory processing in frontal and parietal cortex of the rat, and to further assess the rat as a model of human frontal-parietal processing, we recorded local field potentials (LFPs) from microelectrode arrays implanted in medio-dorsal frontal and posterior parietal cortex of awake rats as they were presented with a succession of frequent "standard" tones and infrequent "oddball" tones. Extending previous results from surface recordings we found, after controlling for the frequencies of the standard and oddball tones, that rat frontal and parietal evoked LFPs (eLFPs) exhibit significantly larger N1 (~40ms latency), P2 (~100ms), N2 (~160ms), P3E (~200-240ms), and P3L(~300-500ms) amplitudes after an oddball tone. These neural oddball effects could contribute to the automatic allocation of attention to rare stimuli. To determine whether these enhanced responses to rare stimuli could be accounted for in terms of stimulus-specific neural adaptation (SSA), we also recorded during single-tone control sessions involving frequent standard or infrequent oddball beeps alone. We compared the difference between rare-tone and frequent-tone response amplitudes in the two-tone context (oddball effect) or single-tone context which isolates the contribution of SSA (SSA effect). An analysis of variance revealed a significant main effect of tone context on rare-tone response enhancements, showing that the rare-tone enhancements were stronger in the two-tone context than the single-tone context. This difference between tone contexts was greatest at the early P3E peak (200-240ms post-beep) in parietal cortex, suggesting true deviance detection by this evoked response component, which cannot be accounted for in terms of simple models of SSA.

Purpose: To verify the effectiveness of the Cognitive Auditory Evoked Potential-P300 (CAEP-P300) for monitoring the therapeutical evolution of students with developmental dyslexia. Methods: Twenty students diagnosed with developmental dyslexia, of both genders, aged between 8 and 14 years, divided into two randomized groups, one of them submitted to a phonological remediation program associated with reading and writing (GI), and the other one representing the control group (GII), participated in the study. The groups were paired up, and the individuals were submitted to two evaluations of the CAEP-P300 and the same interval was kept for both. Paired Student's t-test, ANOVA test, and Pearson's correlation coefficient were used, adopting 5% significance level. Results: The statistical comparison of the pre and post evaluations of each group demonstrated difference in the Phonological Awareness Test (p=0.000) and in the P300 latency (p=0.005) only for GI. Conclusion: CAEP-P300 use for monitoring the therapeutical evolution of children with developmental dyslexia is possible and represents a viable option for intervention programs.

RESUMO Objetivo: Caracterizar os Potenciais Evocados Auditivos de Longa Latência (PEALL) (P1, N1, P2, N2, P300) em campo sonoro, em crianças audiologicamente normais, bem como verificar a estabilidade destes potenciais. Métodos: Trata-se de um estudo prospectivo, longitudinal, composto por 17 crianças audiologicamente normais, na faixa etária de 6 a 13 anos de idade, com limiares de audibilidade dentro da normalidade. Foram captados os PEALL P1, N1, P2, N2, P300 com estímulos de fala e tone burst, em três momentos de avaliação: avaliação inicial (M0), três meses após a avaliação inicial (M3) e nove meses após a avaliação inicial (M9). Resultados: Foi observada diminuição dos valores de latência dos componentes P1 (M0xM3 / M0xM9 / M0xM3xM9) e P2 (M0xM9) e aumento no valor de amplitude do P300 (M0xM3), quando obtidos com estímulo de fala, e diminuição no valor de latência do P300 (M0xM9), obtido com estímulo tone burst. Conclusão: Foi possível identificar os componentes do PEALL na maioria dos indivíduos. Os componentes P1, N1, P2, N2 (tone burst) e N1 e N2 (fala) não sofreram modificações em latências e amplitudes entre os diferentes momentos de avaliação, sugerindo estabilidade deste potencial no período de nove meses. O P300 demonstrou ser um componente mais sensível a esse intervalo de tempo entre as avaliações, pois sofreu modificações indicativas de maturação do sistema nervoso auditivo central. As latências de todos os componentes obtidos com estímulo de fala foram maiores do que com tone burst, demonstrando que estímulos diferentes geram respostas corticais distintas.

PURPOSE: To study the absolute latencies of waves I , III and V and interpeak I-III , III-V and I-V of Auditory brainstem responses obtained in preterm newborns in relation to post-conceptual age, term newborns and six months of age infants, establishing reference values for each age group. METHODS: Retrospective study realized through the analysis of tests performed on 80 infants divided into four groups, being the group one composed per newborns assessed between 35 and 36 weeks post-conceptual age; group two by newborns assessed between 37 and 38 weeks; group three with newborns reviewed between 39 to 40 weeks; and group four with infants evaluated with six months. RESULTS: The wave I absolute latency in the group one was 1.81 ms, decreasing to 1.79 ms in groups two and three, and to 1.70 ms in group four. The wave III latency in group one was 4.74 ms, decreasing to 4.62 ms in group two, to 4.56 ms in the group three and to 4.37 ms in the group four. The wave V latency in group one was 7.14 ms, in the group two it was 7.05 ms, in the group three 6.90 ms; and in the group four it was 6.50 ms. Interpeak latencies were also decreased in all groups. CONCLUSION: The latencies studied decreased with the increasing age and were similar values with the international literature.

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

ABSTRACT Purpose: to compare the findings of minimum levels of answers through air and bone conductions between the Visual Reinforcement Audiometry and the Steady-State Auditory Evoked Potential in infants from six to twelve months, with and without conductive disorder. Methods: sixty children aged six to twelve months were evaluated, 30 presenting conductive disorder, and 30 not presenting it. Children with malformation in the external auditory meatus with neurological alteration and / or genetic syndrome were excluded, as well as patients with sensorineural or mixed hearing loss. The infants were subjected to Visual Reinforcement Audiometry and Steady-State Auditory Evoked Potential evaluation through air and bone conduction on the same day. The results of both assessments were compared and correlated. Results: in the comparison through air conduction, for the group without conductive disorder of the medium ear, the minimum levels of response for 500 and 1000Hz were lower (better thresholds) for Steady-State Auditory Evoked Potential in both ears, and through bone conduction were very similar in all frequencies. Concerning the infants that present conductive disorder, the responses through air conduction were better in all frequencies evaluated when obtained via Steady-State Auditory Evoked Potential test. Through bone conduction, the results were very similar for both groups. Conclusion: it was possible to compare the findings to the minimum levels of response through air and bone conductions between the Visual Reinforcement Audiometry and the Steady-State Auditory Evoked Potential, being that the comparison for bone conduction in both groups presents an equivalence in the results, being very similar. In addition, for the air conduction, in the control group, there was proximity of responses of some frequencies, while the values for the Steady-State Auditory Evoked Potential test were better than the behavioral responses in the conductive disorder group.

OBJETIVO: Comparar o tempo de dois procedimentos de Potencial Evocado Auditivo de Tronco Encefálico Automático (PEATE-A) utilizando taxa de repetição e modo de detecção diferentes. MÉTODOS: Foi realizada a triagem auditiva com Potencial Evocado Auditivo de Tronco Encefálico Automático (PEATE-A) em 30 neonatos, com média de idade de 21 dias. Cada neonato foi submetido a dois procedimentos de triagem auditiva com diferentes equipamentos de PEATE-A (Procedimento 1 e Procedimento 2). O Procedimento 1 utilizou taxa de repetição de 53 Hz e teste estatístico para detecção da resposta denominado one-sample test, e o Procedimento 2 utilizou taxa de repetição de 90 Hz e teste estatístico para detecção da resposta denominado q-sample test. Em seguida, foi registrado o PEATE com estímulo clique como teste padrão ouro, cuja análise das respostas foi realizada por um fonoaudiólogo com experiência neste procedimento. RESULTADOS: O tempo médio observado para o Procedimento 1 considerando ambas orelhas foi de 84,8 (±53,5) segundos; para o Procedimento 2, o tempo médio foi de 27,9 (±20,0) segundos. O primeiro procedimento apresentou tempo de exame aproximadamente três vezes maior quando comparado ao segundo. A análise estatística mostrou diferença significativa entre os tempos dos procedimentos. CONCLUSÃO: O q-sample test e taxa de repetição em torno de 90 Hz nos equipamentos de PEATE-A detectaram a resposta de maneira mais rápida.