Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany.
J Affect Disord. 2020 Nov 1;276:1069-1076. doi: 10.1016/j.jad.2020.07.062. Epub 2020 Jul 18.
Neurosurgical intervention studies have provided direct evidence that the ventral striatum/nucleus accumbens (NAc) mediates symptoms of obsessive-compulsive disorder (OCD), yet meta-analysis of functional neuroimaging studies using symptom provocation revealed no striatal activation differences, and the existing studies reporting hyperactivity found abnormalities in dorsal but not ventral striatal subdivisions. Resting-state neuroimaging evidence holds that corticostriatal areas are more connected both locally and to distant regions, but the functional inferences to be drawn from these altered network characteristics regarding the present experience of OCD symptoms remain limited.
The present study tested whether symptom provocation induces abnormally high striatal network connectivity using two independent datasets of unmedicated patients with OCD. One study (14 patients, 14 matched controls) required passive viewing of OC-related, emotionally aversive and neutral pictures, the other (21 patients, 21 controls) involved self-referential evaluation of the same picture types, as well as distraction from these stimuli (engagement in a simple task).
Heightened local connectivity of the dorsal striatum occurred during passive viewing of briefly presented OC-related pictures in patients, however group differences were also observed in a neutral control condition. In contrast, distracted symptom provocation selectively yielded local connectivity differences of the ventral striatum, as heightened NAc connectivity to its immediate neighborhood was exclusively observed when OC-related pictures were accompanied by concurrent task demands.
Small samples sizes.
In moderately affected patients with OCD, symptom provocation induces a discrete, condition-specific network abnormality anchored in NAc, the location targeted by deep brain stimulation for refractory patients with OCD.
神经外科干预研究提供了直接证据，表明腹侧纹状体/伏隔核（NAc）介导强迫症（OCD）的症状，然而使用症状诱发的功能神经影像学研究的荟萃分析并未显示纹状体激活的差异，并且报告过度活跃的现有研究发现异常位于背侧纹状体而不是腹侧纹状体细分。静息态神经影像学证据表明皮质纹状体区域在局部和远距离区域的连接更为紧密，但从这些改变的网络特征中得出的关于目前 OCD 症状体验的功能推断仍然有限。
本研究使用未经药物治疗的 OCD 患者的两个独立数据集测试了症状诱发是否会导致异常高的纹状体网络连接。一项研究（14 名患者，14 名匹配的对照组）要求被动观看与 OC 相关的、情绪厌恶和中性图片，另一项研究（21 名患者，21 名对照组）涉及对相同图片类型的自我参照评估，以及对这些刺激的分心（从事简单任务）。
在患者中短暂呈现与 OC 相关的图片时，背侧纹状体的局部连接增加，但在中性对照组中也观察到了组间差异。相比之下，分心的症状诱发选择性地产生了腹侧纹状体的局部连接差异，因为当 OC 相关图片伴有并发任务要求时，仅观察到 NAc 与其直接邻近区域的连接增加。
样本量小。
在病情中等的 OCD 患者中，症状诱发会引起特定于条件的离散网络异常，该异常位于 NAc 中，这是难治性 OCD 患者深部脑刺激的目标位置。
