Ghaffari Hamidreza, Yoonessi Ali, Darvishi Mohammad Javad, Ahmadi Akbar
Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Department of Biomedical Engineering, Faculty of Engineering, Shahed University, Tehran, Iran.
Basic Clin Neurosci. 2018 Mar-Apr;9(2):135-146. doi: 10.29252/NIRP.BCN.9.2.135.
Transcranial Direct Current Stimulation (tDCS) has been used as a non-invasive method to increase the plasticity of brain. Growing evidence has shown several brain disorders such as depression, anxiety disorders, and chronic pain syndrome are improved following tDCS. In patients with Obsessive-Compulsive Disorder (OCD), increased brain rhythm activity particularly in the frontal lobe has been reported in several studies using Eectroencephalogram (EEG). To our knowledge, no research has been done on the effects of electrical stimulation on brain signals of patients with OCD. We measured the electrical activity of the brain using EEG in patients with OCD before and after tDCS and compared it to normal participants.
Eight patients with OCD (3 males) and 8 matched healthy controls were recruited. A 64-channel EEG was used to record a 5-min resting state before and after application of tDCS in both groups. The intervention of tDCS was applied for 15 minutes with 2 mA amplitude where anode was placed on the left Dorsolateral Prefrontal Cortex (DLPFC) and cathode on the right DLPFC.
In line with previous studies, the results showed that the power of Delta frequency band in OCD patients are significantly higher than the normal group. Following anodal tDCS, hyperactivity in Delta and Theta bands declined in most channels, particularly in DLPFC (F3, F4) and became similar to normal signals pattern. The reduction in Delta band was significantly more than the other bands.
Anodal tDCS over the left DLPFC significantly decreased the power of frequency bands of Delta and Theta in Patients with OCD. The pattern of EEG activity after tDCS became particularly similar to normal, so tDCS may have potential clinical application in these patients.
经颅直流电刺激（tDCS）已被用作一种增加大脑可塑性的非侵入性方法。越来越多的证据表明，tDCS后一些脑部疾病如抑郁症、焦虑症和慢性疼痛综合征有所改善。在强迫症（OCD）患者中，几项使用脑电图（EEG）的研究报告称大脑节律活动增加，特别是在额叶。据我们所知，尚未有关于电刺激对OCD患者脑信号影响的研究。我们在tDCS前后使用EEG测量了OCD患者的脑电活动，并将其与正常参与者进行比较。
招募了8名OCD患者（3名男性）和8名匹配的健康对照者。两组均使用64通道EEG记录tDCS应用前后5分钟的静息状态。tDCS干预以2 mA的幅度施加15分钟，阳极置于左侧背外侧前额叶皮质（DLPFC），阴极置于右侧DLPFC。
与先前的研究一致，结果表明OCD患者的δ频段功率显著高于正常组。阳极tDCS后，大多数通道中δ和θ频段的活动亢进下降，特别是在DLPFC（F3、F4），并变得与正常信号模式相似。δ频段的下降明显大于其他频段。
左侧DLPFC上的阳极tDCS显著降低了OCD患者δ和θ频段的功率。tDCS后脑电活动模式变得特别类似于正常模式，因此tDCS可能在这些患者中具有潜在的临床应用价值。
