静息态fMRI联合DTI对耳鸣听觉中枢-边缘系统功能连接与结构连接的研究

Subjective tinnitus refers to the phantom sensation that occurs in the absence of any corresponding external auditory source. Due to the lack of effective examination and standard therapy, the neural basis underlying tinnitus still remains unclear. Now tinnitus has become one of the major global health problems. Tinnitus is hypothesized to arise from aberrant neural activity; however, its neural bases are poorly understood. Previous studies and our preliminary results have indicated that the auditory-limbic interactions may play a pivotal role in tinnitus pathophysiology. In the current study, chronic tinnitus patients and well-matched healthy controls will be recruited. Then we collect the demographic data, the auditory examination, the neurological assessment and the multi-modal MRI data, including the T1WI, resting-state fMRI and DTI. Combining the resting-state fMRI with DTI techniques, we will investigate the abnormal functional and structural connectivity or network between auditory and limbic system in tinnitus patients. Combining the imaging, audiology and neurological assessment, the relationships between the abnormalities and specific clinical variables will be detected. Meanwhile, we will explore the correlations between the tinnitus-related functional connectivity and structural connectivity. The present study will lead to a deeper understanding of the neuro-pathophysiology underlying tinnitus and serve as a potential imaging biomarker for confirming the cause of tinnitus and evaluating the curative effect.

耳鸣是人耳在没有相应的外部声音刺激时的主观听觉感知。耳鸣的机制不明，目前尚缺乏客观检查方法及标准化治疗手段，现已成为全球重大卫生问题之一。耳鸣的中枢神经系统病变已得到证实，但其真正的神经病理学基础尚未明确。文献报道及我们前期工作均提示听觉中枢与边缘系统的相互作用可能在耳鸣发生发展过程中起着关键作用。本项目拟收集临床慢性耳鸣患者以及良好匹配的健康对照，采集一般临床资料、听力学指标和神经学量表，进行多模态MRI扫描，包括结构像、静息态fMRI及DTI。通过静息态fMRI及DTI数据处理技术，从结构、功能、网络等角度全面评价耳鸣患者听觉中枢-边缘系统功能连接与结构连接改变，检测异常功能及结构连接与耳鸣临床参数的相关性，并探讨耳鸣听觉中枢-边缘系统功能连接与结构连接的关系。本研究将进一步丰富对耳鸣神经病理学的认识，为临床耳鸣患者明确疾病发病原因和评估治疗预后提供重要的影像学新靶标。

慢性主观性耳鸣是在没有外部声音刺激时人耳的主观听觉感知。慢性耳鸣的机制不明，目前尚缺乏客观检查方法及标准化治疗手段，现已成为全球重大卫生问题之一。慢性耳鸣的中枢神经系统病变已得到证实，但其确切的神经机制尚未明确。文献报道及我们前期工作均提示大脑皮层与边缘系统的相互作用可能在慢性耳鸣发生发展过程中起着关键作用。因此，本研究我们共收集120例临床慢性耳鸣患者以及健康对照100例，采集一般临床资料、听力学指标和多模态功能磁共振（functional magnetic resonance imaging, fMRI）数据，通过联合应用静息态fMRI及弥散张量成像（diffusion tensor imaging, DTI）技术研究耳鸣皮层-边缘系统功能连接与结构连接的异常改变，并检测其与耳鸣临床参数的相关性。主要研究结果表明，慢性耳鸣患者的额颞叶皮层-海马/杏仁核环路有向功能连接异常，且与耳鸣病程及严重程度密切相关；伴抑郁状态的慢性耳鸣患者杏仁核功能异常，且与前额叶-扣带回-颞叶神经环路密切相关；而慢性耳鸣患者听觉皮层、前额叶皮层、视觉皮层等多个皮层脑区与前扣带回皮质网络、默认网络存在的异常功能连接与结构连接。本研究进一步增强了对慢性耳鸣神经病理学机制的理解，额颞叶皮层与边缘系统功能连接与结构连接的异常可能为慢性耳鸣患者的临床治疗及评估治疗预后提供潜在的神经影像学靶点，具有重要的临床意义。