Gabriela Ribeiro Ivo Rodrigues

Potenciais Evocados Auditivos de Estado Estável no diagnóstico audiológico infantil: uma comparação com os Potenciais Evocados Auditivos de Tronco Encefálico

Os Potenciais Evocados Auditivos de Estado Estavel (PEAEE) tem sido apontados como uma tecnica promissora na avaliacao audiologica infantil. OBJETIVO: Investigar o nivel de concordância entre os resultados dos PEAEE e dos Potenciais Evocados Auditivos de Tronco Encefalico (PEATE-clique) em um grupo de criancas com perda auditiva sensorioneural, averiguando assim a aplicabilidade clinica desta tecnica na avaliacao audiologica infantil. FORMA DE ESTUDO: Clinico prospectivo de coorte transversal. MATERIAL E METODO: 15 criancas com idade entre dois e 36 meses e diagnostico de perda auditiva sensorioneural. A concordância entre as respostas dos dois testes foi avaliada por meio do coeficiente de correlacao intraclasse e o teste de McNemar comparou os dois testes quanto a probabilidade de ocorrencia de resposta. RESULTADOS: Os coeficientes de correlacao encontrados foram 0,70; 0,64; 0,49; 0,69; 0,63 e 0,68 respectivamente para as frequencias de 1, 2, 4, 1-2, 2-4 e 1-2-4kHz. No teste de McNemar foi obtido p=0.000, indicando que a probabilidade de se obter resposta presente nos dois testes nao e igual, sendo maior nos PEAEE. CONCLUSAO: A boa concordância observada entre as tecnicas sugere que um exame pode ser complementar ao outro. Os PEAEE, entretanto, promoveram informacoes adicionais nos casos de perdas severas e profundas, acrescentando dados importantes para a reabilitacao destas criancas e proporcionando maior precisao no diagnostico audiologico.

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

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

AUDITORY STEADY-STATE RESPONSE IN CHILDREN WITH COCHLEAR HEARING LOSS

BACKGROUND auditory steady-state response (ASSR) is indicated as a promising technique in the assessment of the hearing status of children. AIM to investigate the level of agreement between the results of the ASSR and the visual reinforcement audiometry (VRA) in a group of children, thus examining the clinical applicability of this technique in hearing assessment of children. METHOD participants were 14 children with ages between 4 and 36 months (mean 16 months) with the diagnosis of cochlear hearing loss. The ASSR was recorded in the frequencies of 0.5, 1, 2 and 4kHz for multiple simultaneous stimulation and the results were compared with the visual reinforcement audiometry (VRA). RESULTS the intraclass correlation coefficients between ASSR and VRA were 0.90, 0.93, 0.93 and 0.89 respectively for the frequencies of 0.5, 1, 2 and 4kHz, indicating a strong correlation between the techniques. CONCLUSION the ASSR can provide accurate information to support the selection of hearing aids for children when it is not possible to perform the VRA.

Efeito de supressão das emissões otoacústicas evocadas por estímulo transiente em lactentes de risco para perda auditiva nascidos pré-termo

PURPOSE: to study the occurrence and magnitude of the transient otoacoustic emissions suppression in pre-term infants with high risk for hearing loss. METHODS: the study was carried out in 15 pre-term infants. The used equipment was ILO USB II V6 Clinical OAE Software from Ododynamics. The used stimulation was linear clicks displayed at the intensity of 60 dB pe SPL (± 5). The contralateral noise (white noise) was set at 60 dB SPL (± 5). RESULTS: From 15 infants, only one did not show bilateral suppression. Suppression effect was shown on 93.3% of the subjects, being 71.4% for both ears and 28.6% for only one ear. The results showed that there was a significant statistical difference between the right and left ears. We could not observe significant differences when actual and gestational age were analyzed. The baby boys showed higher responses when compared to baby girls. CONCLUSIONS: most of the studied population showed OAE suppression effect. White noise was found in the contralateral ear, and reduced the response level of the transient otoacoustic emissions, demonstrating the participation of the efferent system. The responses were different considering the side of the ear, being higher on the right ear and for boys.

Comparação dos estímulos clique e CE-chirp® no registro do Potencial Evocado Auditivo de Tronco Encefálico

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 <15 dBHL (24 ears) and mean age of 27 years. The parameters used for the recording with both stimuli in intensities of 80, 60, 40, 20 dBnHL were alternate polarity and repetition rate of 27.1 Hz. RESULTS: The CE-chirp® latencies for wave V were longer than click latencies at low intensity levels (20 and 40 dBnHL). At high intensity levels (60 and 80 dBnHL), the opposite occurred. Larger wave V amplitudes were observed with CE-chirp® in all intensity levels, except at 80 dBnHL. CONCLUSION: The CE-chirp® showed shorter latencies than those observed with clicks at high intensity levels and larger amplitudes at all intensity levels, except at 80 dBnHL. The waves I and III tended to disappear with CE-chirp® stimulation.

Potenciais evocados auditivos de tronco encefálico por frequência específica e de estado estável na audiologia pediátrica: estudo de caso

Preconiza-se o diagnostico ate os tres meses de idade em criancas com deficiencia auditiva congenita. Apos a etapa inicial de confirmacao do diagnostico, e necessario que se obtenha limiares precisos nas diferentes frequencias, para que seja possivel uma adequada selecao, indicacao e regulagem de aparelhos de amplificacao sonora. Nesse contexto, inserem-se os Potenciais Evocados Auditivos de Tronco Encefalico por Frequencia Especifica (PEATE-FE) e, mais recentemente, os Potenciais Evocados Auditivos de Estado Estavel (PEAEE). O objetivo deste estudo de caso foi apresentar os achados das duas tecnicas para estimar os limiares auditivos em uma crianca de tres meses de idade, com perda auditiva neurossensorial bilateral, diagnosticada utilizando-se como primeiro metodo de avaliacao os Potenciais Evocados Auditivos de Tronco Encefalico com estimulo clique, tanto por via aerea como por via ossea. As duas tecnicas mostraram-se eficientes para estimar os limiares auditivos, com uma vantagem dos PEAEE com relacao ao tempo de duracao de exame.

Comparação do tempo de dois procedimentos com novas tecnologias de Potencial Evocado Auditivo de Tronco Encefálico Automático (PEATE-A)

PURPOSE: To compare the testing time of two Automated Auditory Brainstem Response (AABR) procedures using different repetition rates and detection modes. METHODS: A hearing screening using AABR was performed in 30 newborns with mean age of 21 days. Each newborn was submitted to two hearing screening procedures using different AABR equipments (Procedure 1 and Procedure 2). Procedure 1 used a repetition rate of 53 Hz and the one-sample test for response detection; Procedure 2 used a repetition rate of 90 Hz, and the q-sample test for response detection. The ABR with click stimulus was then registered as gold standard test, and the responses were analyzed by a trained audiologist. RESULTS: The mean time observed for Procedure 1 considering both ears was 84.8 (±53.5) seconds; for Procedure 2 the mean time was 27.9 (±20.0) seconds. The testing time of the first procedure was three times longer than the second one. Statistical analysis showed significant difference between the testing times of the procedures. CONCLUSION: The q-sample test and the repetition rate of 90 Hz used in the AABR equipment showed earlier response detection.

Potenciais evocados auditivos por frequência específica em lactentes com audição normal

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. Method: 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.

New efficient stimuli for evoking frequency-specific auditory steady-state response

Rev Soc Bras Fonoaudiol. 2010;15(1):153-4 (1) Pós-graduanda (Doutorado) em Fonoaudiologia pela Pontifícia Universidade Católica de São Paulo – PUC-SP – São Paulo (SP), Brasil; Fonoaudióloga colaboradora do Centro de Referência em Saúde Auditiva – Centro Audição na Criança da Pontifícia Universidade Católica de São Paulo – PUC-SP – São Paulo (SP), Brasil. (2) Doutora, Professora Titular do Programa de Estudos Pós-Graduados em Fonoaudiologia da Faculdade de Ciências Humanas e da Saúde da Pontifícia Universidade Católica de São Paulo – PUC-SP – São Paulo (SP), Brasil; Fonoaudióloga do Centro de Referência em Saúde Auditiva – Centro Audição na Criança da Pontifícia Universidade Católica de São Paulo – PUC-SP – São Paulo (SP), Brasil. Endereço para correspondência: Gabriela Ribeiro Ivo Rodrigues. Centro Audição na Criança Divisão de Educação e Reabilitação dos Distúrbios da Comunicação – CeAC/DERDIC/PUC-SP. R. Estado de Israel, 860, Vl. Clementino, São Paulo (SP), Brasil, CEP: 04022-040. E-mail: gabrielaivo@hotmail.com New efficient stimuli for evoking frequency-specific auditory steady-state response

A triagem auditiva neonatal antecipa o diagnóstico e a intervenção em crianças com perda auditiva

Purpose To identify the age at diagnosis, intervention and amplification, pre and post Newborn Hearing Screening (NHS) implantation into a hearing health service and to compare with the indicators proposed by Joint Committee on Infant Hearing.Methods Three hundred and thirteen files of children enrolled in the auditory rehabilitation sector were analyzed, verifying if the newborn hearing screening and its results were performed, suspicion and age at the diagnosis, intervention and amplification and if they reach the recommended indicators: 3 months for diagnosis and 6 months for intervention.Results Children identified by the NHS were diagnosed and started the intervention sooner than those who did not perform newborn hearing screening. Considering the institutional demand pre and post NHS implementation, there was a reduction of intervention and amplification ages, post newborn hearing screening implementation. Regardless the NHS outcome (pass/fail), screened children had advantage when compared to the non-screened ones, once, among those screened, the diagnosis, intervention and amplification were anticipated. Less than a half of the children who failed NHS completed the diagnosis and began the intervention in the recommended period.Conclusion NHS anticipates the diagnosis and the intervention in children with hearing loss; however, some factors such as family non-adherence and the diagnosis slowed the process, making it impossible for the recommended indicators to be reached in most of the children.