Altunkaya Sabri, Özmen Güzin, Babur Ercan
Department of Electrical and Electronics Engineering, Necmettin Erbakan University, Konya, Turkey.
Department of Biomedical Engineering, Selcuk University, Konya, Turkey.
Brain Connect. 2025 Aug 6. doi: 10.1177/21580014251362839.
Tinnitus is a neurological condition characterized by the perception of ringing or other phantom sounds in the absence of external auditory stimuli. It affects an estimated 10%-15% of adults worldwide and can significantly affect sleep and mood. Neuroimaging techniques, particularly functional Magnetic Resonance Imaging (fMRI), have been widely used to investigate the auditory system and brain networks in tinnitus. Resting-state fMRI (rs-fMRI), a noninvasive approach, is particularly effective in examining spontaneous neural activity and functional connectivity (FC) across brain regions. This study investigated alterations in FC in individuals with chronic, non-bothersome tinnitus due to acoustic trauma using both static FC (sFC) and dynamic FC (dFC) analyses. A constrained independent component analysis was applied to identify five resting-state networks across the 23 regions of interest. sFC analysis revealed increased connectivity between the posterior cingulate cortex (a key region in the default mode network) and left angular gyrus (in the executive control network) in the tinnitus group. The dFC analysis showed that patients with tinnitus spent significantly more time in a weakly connected state, whereas healthy controls predominantly occupied a more segregated and strongly connected state. Findings suggest reduced network differentiation and altered temporal stability in individuals with non-bothersome tinnitus, potentially influenced by hearing loss. These alterations in both static and dynamic FC patterns provide insights into the neural underpinnings of tinnitus and its interaction with large-scale brain networks. Impact Statement This study demonstrated the value of combining resting-state functional magnetic resonance imaging, constrained independent component analysis, and dynamic functional connectivity to investigate the neural underpinnings of non-bothersome tinnitus. By examining both static and time-varying connectivity across five major resting-state networks, we identified specific alterations in the default mode network, executive control network, and salience network. Our findings suggest that tinnitus affects brain regions involved in attention, memory, and emotion beyond the auditory system. These results offer novel insights into the temporal dynamics of brain networks in tinnitus and may help guide future research on network-level therapeutic strategies.
耳鸣是一种神经病症，其特征是在没有外部听觉刺激的情况下感知到耳鸣或其他幻听。据估计，全球10%-15%的成年人受其影响，它会显著影响睡眠和情绪。神经成像技术，特别是功能磁共振成像（fMRI），已被广泛用于研究耳鸣患者的听觉系统和脑网络。静息态fMRI（rs-fMRI）是一种非侵入性方法，在检查大脑区域间的自发神经活动和功能连接（FC）方面特别有效。本研究使用静态FC（sFC）和动态FC（dFC）分析，调查了因声创伤导致的慢性、非困扰性耳鸣个体的FC变化。应用约束独立成分分析来识别23个感兴趣区域中的五个静息态网络。sFC分析显示，耳鸣组后扣带回皮质（默认模式网络中的关键区域）与左角回（执行控制网络中）之间的连接增加。dFC分析表明，耳鸣患者处于弱连接状态的时间明显更长，而健康对照主要处于更隔离且连接更强的状态。研究结果表明，非困扰性耳鸣个体的网络分化减少且时间稳定性改变，可能受听力损失影响。这些静态和动态FC模式的变化为耳鸣的神经基础及其与大规模脑网络的相互作用提供了见解。影响声明 本研究证明了结合静息态功能磁共振成像、约束独立成分分析和动态功能连接来研究非困扰性耳鸣神经基础的价值。通过检查五个主要静息态网络的静态和随时间变化的连接性，我们确定了默认模式网络、执行控制网络和突显网络中的特定变化。我们的研究结果表明，耳鸣会影响听觉系统之外涉及注意力、记忆和情绪的脑区。这些结果为耳鸣脑网络的时间动态提供了新见解，并可能有助于指导未来关于网络水平治疗策略的研究。
