Interpretação clínica do potencial evocado auditivo do tronco encefálico na frequência específica de 1000Hz em recém nascidos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Objective: To Establish normative data for clinical interpretation of frequency specific auditory brainstem response in 1000Hz, in full term newborns under 1 month of age, to be based on protocol by Hood (1998) and adapted to attended population on DERDIC. Method: Auditory brainstem response (ABR) stimulus click and toneburst 1000Hz, were performed in 10 newborns (NB), full term, with average chronological age of 24 days, without risks factors to hearing impairment, based on JCIH (2000), with normal response to EOAT and timpanometry type A. The analysis of results performed comparing the wave V latency for sex, ear and stimuli. Results: Response to ABR, stimuli click and toneburst 1000Hz, were obtained in all subject of the present research, showing the normal function of the structures of nerve vestibulococlear and brainstem pathway. No significant difference was found among the responses by sex and ear. Electrophysiological threshold were obtained in 30dBnNA (:t6,4) ranging from 20 to 40dBnNA in stimuli click and 35dBnNA (:t4,2) ranging from 30 to 40dBnNA to toneburst 1000Hz. The stimuli of low frequency (1000Hz) presented particular response, showed larger latency when compared as the high frequency (click) (p=O). Average latencies on stimuli click were 6,85ms, 7,36ms, 7,9ms, 8,45 and 8,4ms on intensities of 80, 60, 40, 30 and 20dBnNA respectively. Responses to toneburst 1000Hz were obtained at average latencies of 9,24ms, 9,88ms, 10,45ms and 11,2ms on intensities of 80, 60, 40 and 30dBnNA respectively. Conclusion: Obtaining specific frequency ABR in 1000Hz is feasible in newborns included latencies as threshold values . These values can be use as normative data for clinical interpretation for normal hearing. Future data on Visual Response Audiometry (VRA) at a future follow up study will further validate these conclusions

ASSUNTO(S)

recem-nascido surdez fonoaudiologia potenciais evocados auditivos

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