强迫症及其同胞左右半球功能偏侧化脑机制研究

Patients with Obsessive-Compulsive Disorder (OCD) are associated with the hemispheric lateralization abnormalities, which is the foundation for studying OCD brain mechanism. Despite some recent work on neuroimaging studies, very little is still known about the functional activities at rest, i.e., resting state, in this clinical group. In particular, whether such an abnormality characteristic is a "trait" or a "state" is not yet fully unknown. Most recent studies have suggested that there were abnormal default mode networks (DMN) in OCD patients during resting-state and major abnormalities were increasing activities on the left hemisphere, which suggested that there is abnormal activities between left hemisphere and right hemisphere during resting-state in this clinical group. The current study aims to examine the resting-state of patients with OCD and their unaffected siblings. Moreover, it will focus on the mechanism of hemispheric lateralization in patients with OCD patients and attempt to identify any potential biological marker for the prevention and treatment of OCD. Based on the existing findings from the literature, we expect both patients OCD and their unaffected siblings will show a hemispheric lateralization during resting-state.

强迫症（OCD）左右半球功能偏侧化机制是研究其脑机制的前提和基础。OCD患者左右半球分工模式存在异常，但是，OCD患者在静息状态下左半球和右半球的活动模式，迄今还不清楚。另外，OCD患者这种特征性的左右半球活动模式是一种"特质"还是一种"状态"，也尚未知晓。研究发现OCD患者在静息状态下的默认网络存在异常，且主要表现为左半球功能增强，这提示OCD患者在静息状态下左右半球的活动模式存在异常。为此，我们推测OCD患者在静息状态下左右半球功能存在偏差化异常，另外，OCD患者的未患病同胞较正常人群具有更多患强迫症的素质，因此，我们推测未患病同胞可能存在相似的偏侧化异常。为证实这一假说，我们拟利用静息态fMRI采集脑神经元的活动信息，运用基于体素的镜像同伦功能连接方法分析静息状态下左半球和右半球的活动特征。本课题将从新的视角阐述OCD患者静息状态下左右脑偏侧化机制，为OCD的防治提供新的生物学标记。

本研究采用基于体素的镜像等位功能连接方法探讨了强迫症(OCD)患者及其未患病一级同胞在静息状态下左右半球神经元的活动特征，研究结果发现：(1) OCD患者在静息状态下左右半球功能存在偏差化异常，主要表现双侧颞叶和脑岛的功能连接增强；(2) OCD患者的未患病一级同胞在双侧的颞叶和前额叶功能连接增强；(3) OCD患者及其同胞都在双侧颞叶存在功能连接增强，提示其为强迫症的一种新的生物学标记物；(4) OCD患者及其未患病一级同胞同时存在左右半球结构的偏侧化异常。上述结果证实了我们提出OCD患者在静息状态下左右半球功能存在偏差化异常，且未患病一级同胞存在相似异常的假说，为OCD的防治提供新的生物学标记物。