TRI Tinnitus Clinic, Brai²n, TRI & Department of Neurosurgery, University Hospital Antwerp, Wilrijkstraat 10, 2650 Edegem, Belgium.
Eur J Neurosci. 2011 Sep;34(5):718-31. doi: 10.1111/j.1460-9568.2011.07793.x. Epub 2011 Aug 16.
Tinnitus is characterized by an ongoing conscious perception of a sound in the absence of any external sound source. Chronic tinnitus is notoriously characterized by its resistance to treatment. In the present study the objective was to verify whether the neural generators and/or the neural tinnitus network, evaluated through EEG recordings, change over time as previously suggested by MEG. We therefore analyzed the source-localized EEG recordings of a very homogenous group of left-sided narrow-band noise tinnitus patients. Results indicate that the generators involved in tinnitus of recent onset seem to change over time with increased activity in several brain areas [auditory cortex, supplementary motor area and dorsal anterior cingulate cortex (dACC) plus insula], associated with a decrease in connectivity between the different auditory and nonauditory brain structures. An exception to this general connectivity decrease is an increase in gamma-band connectivity between the left primary and secondary auditory cortex and the left insula, and also between the auditory cortices and the right dorsal lateral prefrontal cortex. These networks are both connected to the left parahippocampal area. Thus acute and chronic tinnitus are related to differential activity and connectivity in a network comprising the auditory cortices, insula, dACC and premotor cortex.
耳鸣的特征是在没有任何外部声源的情况下持续存在声音感知。慢性耳鸣以其对治疗的抵抗力而臭名昭著。在本研究中，目的是验证通过 EEG 记录评估的神经发生器和/或神经耳鸣网络是否会随时间变化，正如 MEG 之前所建议的那样。因此，我们分析了一组非常同质的左侧窄带噪声耳鸣患者的源定位 EEG 记录。结果表明，新近发作的耳鸣所涉及的发生器似乎随时间变化而变化，几个脑区的活动增加[听觉皮层、补充运动区和背侧前扣带皮层（dACC）加岛叶]，同时不同听觉和非听觉脑结构之间的连通性下降。这种普遍连通性下降的一个例外是左初级和次级听觉皮层与左岛叶之间以及听觉皮层与右背外侧前额叶皮层之间的伽马带连通性增加。这些网络都与左海马旁回区相连。因此，急性和慢性耳鸣与包括听觉皮层、岛叶、dACC 和运动前皮层在内的网络中的差异活动和连通性有关。
