Pineda Jaime A, Moore F Richard, Viirre Erik
Department of Cognitive Science University of California, San Diego, La Jolla, California 92093, USA.
Int Tinnitus J. 2008;14(1):17-25.
Recent studies have indicated that the pathophysiological basis for tinnitus may be abnormal activity in the auditory areas of the brain rather than aberrant activity in the periphery. Tinnitus-related activity leads to changes in tonotopic representation in auditory cortex. However, such reorganization can be reversed through training-induced changes in the response pattern of cortical neurons. We address this problem by using customized sounds that reproduce the subjective experience to reduce overactive auditory circuits. The results of two preliminary studies indicate that customized sound therapy (CST*) aimed at this central dysfunction reduces tinnitus quickly and safely. Participants described immediate relief, showed changes on the Tinnitus Handicap Questionnaire, and reported changes in hearing threshold within 3 weeks. We also saw changes in the intensity dependence of the auditory N100 in tinnitus patients, supporting the idea that tinnitus reflects a reorganization of tonotopic maps in the auditory cortex. The main correlate of this reorganization was the enhanced contrast between responses to the perceived tinnitus pitch and tones approximately one octave lower. After 3 weeks of CST, the intensity dependence to the tinnitus pitch decreased, making these responses more similar to those from normal subjects responding to tones in the same frequency.
近期研究表明，耳鸣的病理生理基础可能是大脑听觉区域的异常活动，而非外周的异常活动。耳鸣相关活动会导致听觉皮层音调定位表征的变化。然而，这种重组可通过训练诱导的皮层神经元反应模式变化得以逆转。我们通过使用定制声音来重现主观体验，以减少过度活跃的听觉回路，从而解决这一问题。两项初步研究结果表明，针对这种中枢功能障碍的定制声音疗法（CST*）能快速且安全地减轻耳鸣。参与者表示耳鸣症状立即得到缓解，耳鸣障碍问卷出现变化，且在3周内听力阈值也有改变。我们还观察到耳鸣患者听觉N100强度依赖性的变化，支持了耳鸣反映听觉皮层音调定位图重组的观点。这种重组的主要相关因素是对感知到的耳鸣音调与低约一个八度的音调反应之间对比度的增强。经过3周的CST后，对耳鸣音调的强度依赖性降低，使这些反应更类似于正常受试者对相同频率音调的反应。
