Department of Phoniatrics and Audiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
PLoS One. 2013;8(1):e53180. doi: 10.1371/journal.pone.0053180. Epub 2013 Jan 10.
The phantom auditory perception of subjective tinnitus is associated with aberrant brain activity as evidenced by magneto- and electroencephalographic studies. We tested the hypotheses (1) that psychoacoustically measured tinnitus loudness is related to gamma oscillatory band power, and (2) that tinnitus loudness and tinnitus-related distress are related to distinct brain activity patterns as suggested by the distinction between loudness and distress experienced by tinnitus patients. Furthermore, we explored (3) how hearing impairment, minimum masking level, and (4) psychological comorbidities are related to spontaneous oscillatory brain activity in tinnitus patients.
Resting state oscillatory brain activity recorded electroencephalographically from 46 male tinnitus patients showed a positive correlation between gamma band oscillations and psychoacoustic tinnitus loudness determined with the reconstructed tinnitus sound, but not with the other psychoacoustic loudness measures that were used. Tinnitus-related distress did also correlate with delta band activity, but at electrode positions different from those associated with tinnitus loudness. Furthermore, highly distressed tinnitus patients exhibited a higher level of theta band activity. Moreover, mean hearing loss between 0.125 kHz and 16 kHz was associated with a decrease in gamma activity, whereas minimum masking levels correlated positively with delta band power. In contrast, psychological comorbidities did not express significant correlations with oscillatory brain activity.
Different clinically relevant tinnitus characteristics show distinctive associations with spontaneous brain oscillatory power. Results support hypothesis (1), but exclusively for the tinnitus loudness derived from matching to the reconstructed tinnitus sound. This suggests to preferably use the reconstructed tinnitus spectrum to determine psychoacoustic tinnitus loudness. Results also support hypothesis (2). Moreover, hearing loss and minimum masking level correlate with oscillatory power in distinctive frequency bands. The lack of an association between psychological comorbidities and oscillatory power may be attributed to the overall low level of mental health problems in the present sample.
主观耳鸣的幻听知觉与异常的大脑活动有关，这已被脑磁图和脑电图研究证明。我们检验了以下假设：（1）心理声学测量的耳鸣响度与伽马振荡频段功率有关；（2）耳鸣响度和与耳鸣相关的苦恼与耳鸣患者所经历的响度和苦恼之间的区别所暗示的不同大脑活动模式有关。此外，我们还探讨了（3）听力损伤、最小掩蔽级和（4）心理共病如何与耳鸣患者的自发性振荡大脑活动有关。
从 46 名男性耳鸣患者记录的静息状态振荡脑活动显示，伽马波段振荡与用重建的耳鸣声音确定的心理声学耳鸣响度之间存在正相关，但与用于其他心理声学响度测量的参数无关。与耳鸣相关的苦恼也与 delta 波段活动相关，但在与耳鸣响度相关的电极位置不同。此外，高度苦恼的耳鸣患者表现出更高的 theta 波段活动。此外，0.125 kHz 至 16 kHz 之间的平均听力损失与伽马活动减少有关，而最小掩蔽级与 delta 波段功率呈正相关。相比之下，心理共病与振荡大脑活动没有显著相关性。
不同的临床相关耳鸣特征与自发性大脑振荡功率有不同的关联。结果支持假设 1，但仅限于与重建的耳鸣声音匹配的耳鸣响度。这表明最好使用重建的耳鸣频谱来确定心理声学耳鸣响度。结果也支持假设 2。此外，听力损失和最小掩蔽级与特定频段的振荡功率相关。在本样本中，心理健康问题的总体水平较低，这可能导致心理共病与振荡功率之间没有关联。
