Department of Physics and Astronomy, Brain and Mind Institute, University of Western Ontario, London, ON, Canada.
Sensation and Perception Research Group, GIGA Consciousness, University of Liège, Liège, Belgium.
J Neurol. 2019 Sep;266(9):2197-2207. doi: 10.1007/s00415-019-09390-1. Epub 2019 May 31.
Tinnitus, the perception of sound in the absence of external stimuli, is often a disturbing symptom for which the underlying functional neuroanatomy still remains poorly understood. Most studies have focused solely on functional connectivity changes in the auditory cortex of tinnitus patients. The aim of this study was to investigate whether a correlation exists between tinnitus behavioural scores and functional brain connectivity of five resting-state networks comprising the auditory, the default mode, the external control left and right, and the salience network. For this purpose, a large sample of one hundred and thirty-five subjects underwent resting-state functional magnetic resonance imaging and their behavioural scores were obtained using clinical evaluations. Networks were extracted using independent component analysis, and functional connectivity patterns in the extracted networks were evaluated by a graph theoretical approach. The effects of tinnitus for each network were investigated by correlating the graph strength of all the regions with the tinnitus behavioural scores using stepwise fit regression analysis. Results indicated that alterations of functional interactions between key neural circuits of the brain are not limited to one single network. In particular, tinnitus distress showed a strong correlation with the connectivity pattern within and between the right executive control network and the other four resting-state networks, indicating that tinnitus distress is probably the consequence of a hyperactive attention condition. Among the behavioural scores, the strongest correlation was observed between age and hearing loss, while the tinnitus objective loudness was not correlated with any behavioural scores.
耳鸣是指在没有外部刺激的情况下感知到声音，常常是一种令人困扰的症状，但其潜在的功能神经解剖结构仍知之甚少。大多数研究仅关注耳鸣患者听觉皮层的功能连接变化。本研究旨在探讨耳鸣行为评分与包括听觉、默认模式、左右外部控制和突显网络在内的五个静息态网络的功能脑连接之间是否存在相关性。为此，一百三十五名受试者接受了静息态功能磁共振成像，并用临床评估获得他们的行为评分。使用独立成分分析提取网络，并通过图论方法评估提取网络中的功能连接模式。通过逐步拟合回归分析，将所有区域的图强度与耳鸣行为评分相关联，来研究每个网络的耳鸣效应。结果表明，大脑关键神经回路之间功能相互作用的改变不仅限于一个单一的网络。特别是，耳鸣困扰与右侧执行控制网络与其他四个静息态网络内部和之间的连接模式之间存在很强的相关性，这表明耳鸣困扰可能是过度活跃的注意力状态的结果。在行为评分中，年龄和听力损失之间的相关性最强，而耳鸣客观响度与任何行为评分均无相关性。
