LIM-23, Department of Psychiatry, Faculdade de Medicina, Universidade de São Paulo, SP, Brazil.
LIM-23, Department of Psychiatry, Faculdade de Medicina, Universidade de São Paulo, SP, Brazil; Department of Methods and Techniques in Psychology, Pontifical Catholic University, São Paulo, SP, Brazil.
J Affect Disord. 2024 Jun 15;355:175-183. doi: 10.1016/j.jad.2024.03.141. Epub 2024 Mar 26.
Non-invasive neuromodulation is a promising intervention for obsessive-compulsive disorder (OCD), although its neurobiological mechanisms of action are still poorly understood. Recent evidence suggests that abnormalities in the connectivity of the default mode network (DMN) and the supplementary motor area (SMA) with other brain regions and networks are involved in OCD pathophysiology. We examined if transcranial direct current stimulation (tDCS) alters these connectivity patterns and if they correlate with symptom improvement in treatment-resistant OCD.
In 23 patients from a larger clinical trial (comparing active tDCS to sham) who underwent pre- and post-treatment MRI scans, we assessed resting-state functional MRI (rs-fMRI) data. The treatment involved 30-minute daily tDCS sessions for four weeks (weekdays only), with the cathode over the SMA and the anode over the left deltoid. We conducted whole-brain connectivity analysis comparing active tDCS-treated to sham-treated patients.
We found that active tDCS, but not sham, led to connectivity increasing between the DMN and the bilateral pre/postcentral gyri (p = 0.004, FDR corrected) and temporal-auditory areas plus the SMA (p = 0.028, FDR corrected). Also, symptom improvement was directly associated with connectivity increasing between the left lateral sensorimotor network and the left precuneus (r = 0.589, p = 0.034).
Limited sample size (23 participants with resting-state neuroimaging), inability to analyze specific OCD symptom dimensions (e.g., harm, sexual/religious, symmetry/checking, cleaning/contamination).
These data offer novel information concerning functional connectivity changes associated with non-invasive neuromodulation interventions in OCD and can guide new brain stimulation interventions in the framework of personalized interventions.
非侵入性神经调节是治疗强迫症（OCD）的一种很有前途的干预手段，尽管其作用的神经生物学机制仍知之甚少。最近的证据表明，默认模式网络（DMN）和补充运动区（SMA）与其他大脑区域和网络之间的连接异常与 OCD 的病理生理学有关。我们研究了经颅直流电刺激（tDCS）是否会改变这些连接模式，以及它们是否与治疗抵抗性 OCD 的症状改善相关。
在一项更大的临床试验（比较活性 tDCS 与假刺激）的 23 名患者中，他们在治疗前后接受了 MRI 扫描，我们评估了静息态功能磁共振成像（rs-fMRI）数据。治疗包括四周（仅工作日）每天 30 分钟的 tDCS 治疗，阴极置于 SMA 上，阳极置于左侧三角肌上。我们对活性 tDCS 治疗组与假刺激治疗组进行了全脑连接分析。
我们发现，与假刺激相比，活性 tDCS 导致 DMN 与双侧额/顶叶（p = 0.004，经 FDR 校正）和颞听觉区域加 SMA 之间的连接增加（p = 0.028，经 FDR 校正）。此外，症状改善与左侧外侧感觉运动网络与左侧楔前叶之间的连接增加直接相关（r = 0.589，p = 0.034）。
样本量有限（23 名接受静息态神经影像学检查的患者），无法分析特定的 OCD 症状维度（例如，伤害、性/宗教、对称/检查、清洁/污染）。
这些数据提供了与 OCD 中神经调节干预相关的功能连接变化的新信息，并为个性化干预框架中的新脑刺激干预提供了指导。
