Department of Psychiatry, Bellvitge University Hospital, Bellvitge Biomedical Research Institute-IDIBELL, Barcelona, Spain.
Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain.
Curr Top Behav Neurosci. 2021;49:269-300. doi: 10.1007/7854_2020_203.
In the last 20 years, functional magnetic resonance imaging (fMRI) has been extensively used to investigate system-level abnormalities in the brain of patients with obsessive-compulsive disorder (OCD). In this chapter, we start by reviewing the studies assessing regional brain differences between patients with OCD and healthy controls in task-based fMRI. Specifically, we review studies on executive functioning and emotional processing, protocols in which these patients have been described to show alterations at the behavioral level, as well as research using symptom provocation protocols. Next, we review studies on brain connectivity alterations, focusing on resting-state studies evaluating disruptions in fronto-subcortical functional connectivity and in cortical networks. Likewise, we also review research on effective connectivity, which, different from functional connectivity, allows for ascertaining the directionality of inter-regional connectivity alterations. We conclude by reviewing the most significant findings on a topic of translational impact, such as the use of different fMRI measurements to predict response across a variety of treatment approaches. Overall, results suggest that there exists a pattern of regions, involving, but not limited to, different nodes of the cortico-striatal-thalamo-cortical circuits, showing robust evidence of functional alteration across studies, although the nature of the alterations critically depends on the specific tasks and their particular demands. Moreover, such findings have been, to date, poorly translated into clinical practice. It is suggested that this may be partially accounted for by the difficulty to integrate into a common framework results obtained under a wide variety of analysis approaches.
在过去的 20 年中，功能磁共振成像（fMRI）被广泛用于研究强迫症（OCD）患者大脑的系统水平异常。在本章中，我们首先回顾了评估基于任务的 fMRI 中 OCD 患者与健康对照组之间大脑区域差异的研究。具体来说，我们回顾了关于执行功能和情绪处理的研究，这些研究方案中描述了这些患者在行为层面上的改变，以及使用症状诱发方案的研究。接下来，我们回顾了关于大脑连接改变的研究，重点关注静息态研究评估额皮质下功能连接和皮质网络的中断。同样，我们还回顾了关于有效连接的研究，与功能连接不同，有效连接可以确定区域间连接改变的方向性。最后，我们回顾了一个具有转化影响的主题的最重要发现，例如使用不同的 fMRI 测量来预测各种治疗方法的反应。总的来说，结果表明，存在一个涉及但不限于皮质-纹状体-丘脑-皮质回路不同节点的区域模式，这些区域在研究中显示出功能改变的有力证据，尽管改变的性质严重取决于特定的任务及其特定的要求。此外，迄今为止，这些发现尚未很好地转化为临床实践。有人认为，这可能部分归因于将在各种分析方法下获得的结果纳入一个通用框架存在困难。
