ABSTRACT
Introduction: The effects of lead on children's health have been widely studied. Aim: To analyze the correlation between the long latency auditory evoked potential N2 and cognitive P3 with the level of lead poisoning in Brazilian children. Methods: This retrospective study evaluated 20 children ranging in age from 7 to 14 years at the time of audiological and electrophysiological evaluations. We performed periodic surveys of the lead concentration in the blood and basic audiological evaluations. Furthermore, we studied the auditory evoked potential long latency N2 and cognitive P3 by analyzing the absolute latency of the N2 and P3 potentials and the P3 amplitude recorded at Cz. At the time of audiological and electrophysiological evaluations, the average concentration of lead in the blood was less than 10 ug/dL. Results: In conventional audiologic evaluations, all children had hearing thresholds below 20 dBHL for the frequencies tested and normal tympanometry findings; the auditory evoked potential long latency N2 and cognitive P3 were present in 95% of children. No significant correlations were found between the blood lead concentration and latency (p = 0.821) or amplitude (p = 0.411) of the P3 potential. However, the latency of the N2 potential increased with the concentration of lead in the blood, with a significant correlation (p = 0.030). Conclusion: Among Brazilian children with low lead exposure, a significant correlation was found between blood lead levels and the average latency of the auditory evoked potential long latency N2; however, a significant correlation was not observed for the amplitude and latency of the cognitive potential P3...
Subject(s)
Humans , Male , Female , Child , Adolescent , Lead/toxicity , Cognition/radiation effects , Electrophysiology , Environmental Exposure , Evoked Potentials, Auditory , Threshold Limit Values , Lead Poisoning, Nervous System, ChildhoodABSTRACT
OBJETIVO: avaliar as medidas repetidas da resposta de ressonância da orelha externa sem (REUR) e com uso de amplificação (REAR) e o ganho de inserção (REIG), realizados face a face e via teleconsulta. MÉTODO: estudo prospectivo longitudinal. Foram realizadas quatro repetições da REUR, REAR e REIG (com estímulo speech noise apresentado em 65 dB NPS e 0º azimute) em 19 orelhas de adultos ouvintes normais, via face a face (F) e teleconsulta síncrona por controle remoto de aplicativo (T) e vídeo interativo. O software Polycom PVX foi utilizado para compartilhamento e transmissão de áudio e vídeo. A conexão foi realizada via LAN (Local Area Network) USP na velocidade de 384 kbps Foi calculado o erro causal (Dalhberg) entre as quatro medidas para frequências de 250 a 8000 Hz. RESULTADOS: os erros casuais entre as medidas F e T foram muito semelhantes, sendo maiores nas frequências acima de 4 kHz. As diferenças e variações entre as medidas F e T estavam dentro da magnitude de variabilidade do procedimento de medidas com microfone sonda. CONCLUSÃO: as medidas com microfone sonda via teleconsulta fornece resultados confiáveis e similares aos obtidos pelo procedimento padrão.
PURPOSE: to evaluate the repeated measurements of the real ear unaided response (REUR), real ear aided response (REAR) and insertion gain (REIG) conducted as face to face (F) and via telecounselling (T). METHOD: longitudinal prospective study. Four measures of REUR, REAR and REIG (carried out with speech noise stimulus presented at 65 dB SPL at 0° azimuth) were obtained in 19 ears in normal hearing adults, face to face and via synchronous telecounsellings with remote control of the real ear equipment and interactive video. Polycom PVX software was used for desktop sharing and video and audio transmission. The Loca Area Network (LAN) USP was used for the connection (transmission rate: 384 kbps). Dahlbergs casual errors were calculated for obtaining the measures for frequencies from 250 to 8000 Hz. RESULTS: casual errors between F and T measures were very similar, being greater for frequencies above 4 kHz. The differences between F and T measures were no greater than the variability reported for real ear measures. CONCLUSION: probe microphone measures obtained via telecounselling provides reliable results and similar to those obtained by standard procedures.