Estudo do padrão de normalidade do potencial evocado auditivo de adultos ouvintes normais por meio de um novo equipamento de diagnóstico desenvolvido

• Ano de defesa: 2010
• Autor(a) principal: Soares, Ilka do Amaral [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Audiologia; Potenciais evocados auditivos; Diagnóstico; Audiology; Evoked Potentials, Auditory; Diagnosis
• Link de acesso: http://repositorio.unifesp.br/handle/11600/9565

Objective: To validate responses of the Auditory Brainstem Response (ABR) using a new equipment developed in Brazil. Method: The annalyses of the absolute latencies, inter slopes, and magnitude of the waves I and V, using a new equipment developed to asses the Experimental Group 1 (76 participants with normal hearing). Analysis of the ABR using the gold-standard equipment, EP15/Interacoustis, where performed in Gold Group 1 (15 participants with normal hearing) and Gold Group 2 (15 participants with sensorineural hearing loss). In order to assess the validity of the new equipment, analysis of the ABR were performed using the new equipment with participants of the Gold Group 1 to compare with participants from the Experimental Group 2, and with participants from the Gold Group 2 to compare with participants from the Experimental Group 3. The stimulus used to obtain the evocated responses was a non-filtrated click sound, with a duration of 100 μs and a total of 2,000 stimuli. All stimuli were given in the negative (rarefaction wave) polarities in a stimulation frequency of 13.1 clicks, with an intensity of 80 dB Nan, an interval of 10 milliseconds and a filter band-pass set between 100 and 3000Hz. The results were statistically analyzed considering a significance level of 0.05. Results: The means for the absolute latencies and inter slopes for the specific waves using the new equipment were: I=1.50, III=3.57, V=5.53, I-III=2.06, III-V=1.96 e I-V=4.02. Statistically significant gender differences were observed for the absolute latencies in wave III (p=0,000) and V (p=0,000) as well as for the inter slopes I-III (p=0,007) and I-V (p=0,001). The mean magnitude values for wave I and V were 0.384 μV and 0.825 μV, respectively. No statistically significant differences between the new equipment and the gold-standard were observed when comparing the results for absolute latencies and inter slopes in the same individual (with normal hearing or with sensorineural hearing loss). Conclusions: The components of the ABR assessed in adults with no hearing impairments using the new equipment were similar for both ears, with latencies significantly lower for women than for men. Moreover, the latencies of the ABR in the same individual (either normal or with sensorineural hearing loss) did not differ between the new equipment and the gold-standard equipament. In hearing loss of mild to moderate degree the most frequent finding on the ABR was the presence of Waves I, III, V and absolute latencies and inter slopes within normal limits. The referent values of normality for the ABR were obtained in adults with normal hearing.