Avaliação de indivíduos com queixa de zumbido por meio de procedimentos psicoacústicos e eletroacústicos

Abstract

Introduction: In an attempt to understand some aspects related with tinnitus we formulated the hypothesis that there would be a dysfunction of the efferent auditory system, more precisely in the region of the superior medial olivocochlear system (SMOCS). In addition to Suppressíon of Otoacoustic Emissions by Transient Stimuli (SOAETS), Acoustic Reflex measurements of stapedial muscle and Masking Levei Difference (MLD) may represent an alternative to assess the olivocochlear system (OCS). Objective: To assess the OCS in subjects with complaints of tinnitus using psychoacoustic and electroacoustic procedures. Method: We assessed 60 subjects, male or female, aged between 20 and 59 years, 30 with tinnitus (experimental group) and 30 without tinnitus (control group). We analyzed Masking Levei Difference (MLD) for the frequency of 500Hz bilaterally, at narrow band 40 dBHL, in S0R0 and SrR0 conditíons, SOAETS for white noise 50 dBHL, in contralateral condition, and Stapedial Muscle Acoustic Reflex (AR) contralaterally for frequencies 500, 1000 and 2000Hz. Results: In the experimental group, the mean value of MLD was 9.77dB, AR contralateral 94.4 dBHL and SOAETS ranged from 2.14 to 4.38. In the contrai group, the mean value for MLD was 9.73dB, AR contralateral was about 94.4dBHL and SOAETS ranged from 2.27 to 4.88. Sensitivity and specificity analyses, respectively, showed MLD (500 Hz) X AR (500 Hz) - 33% and 77%, MLD (500 Hz) X SOAETS (700 Hz) - 66% and 44%, and AR (500 Hz) X SOAETS' (700 Hz) - 71.45% and 47.85%, AR (1000 Hz) X SOAETS (1000 Hz)- 60%' and 68%, and AR (2000 Hz) X SOAETS (2000 Hz) - 42.85% and 69.55%. Conclusion: Despite the fact that they were not'statistically significant, MLD and AR tests showed levels of sensitivity and specificity that could contribute to the topographic diagnosis of tinnitus, because the experimental group presented different intra-group performance, which was at the same time different from the inter-group analysis. Further studies should be performed to confirm the efficacy of these two procedures