Electroacoustic and electrophysiological auditory assessment in aphasic individuals

ABSTRACT Purpose: to verify the functioning of the outer hair cells and the medial efferent olivocochlear system, and the integrity of the auditory pathways in the brainstem up to the auditory cortex, in aphasic individuals. Methods: the sample comprised 20 individuals - 10 without aphasia and 10 with it, aged from 21 to 58 years. The procedures used were the research of the otoacoustic emissions by a transient stimulus with and without noise, and the cognitive potential (tone-burst and speech stimuli). The findings were analyzed based on descriptive statistics. Results: the suppression effect was more present in individuals without aphasia when compared with the aphasic ones. In the cognitive potential, the mean latency values of P3 was within normality standards, with a higher latency in the individuals presented with aphasia for the tone-burst stimulus in both ears. A statistically significant difference of the P3-N2 amplitude was observed for the tone-burst stimulus, comparing the ears in both groups, and for speech stimulus only to the left ear in both groups. Conclusions: aphasic individuals did not present significant differences regarding suppression of the otoacoustic emissions. As for the cognitive potential, the aphasic individuals presented higher latency values when compared to those with no aphasia.

摘要 目的：验证失语症（aphasia）患者的外毛细胞（outer hair cells）、内侧橄榄耳蜗传出系统（medial efferent olivocochlear system）功能，以及脑干直至听觉皮层的听觉通路完整性。
方法：本研究纳入20名受试者，其中10名无失语症、10名罹患失语症，年龄范围为21~58岁。本次检测采用瞬态刺激诱发性耳声发射（otoacoustic emissions）（含噪声与不含噪声两种刺激模式），以及认知诱发电位（cognitive potential）检测，具体范式包括短声刺激（tone-burst）及言语刺激。所有检测结果均采用描述性统计学（descriptive statistics）方法进行分析。
结果：与失语症患者相比，非失语症受试者的耳声发射抑制效应更为显著。在认知诱发电位检测中，P3波（P3）的平均潜伏期处于正常参考范围内；双耳短声刺激下，失语症患者的潜伏期均更高。两组受试者在短声刺激下的P3-N2波幅（P3-N2 amplitude），双耳间均存在统计学显著差异（statistically significant difference）；而言语刺激仅在左耳组间存在该差异。
结论：失语症患者的耳声发射抑制效应未出现显著组间差异。而就认知诱发电位而言，失语症患者的潜伏期较非失语症受试者更高。