Abstract:
Cranial electrotherapy stimulation (CES) is a neuromodulation tool used for treating several clinical disorders, including insomnia, anxiety, and depression. More recently, a limited number of studies have examined CES for altering affect, physiology, and behavior in healthy, non-clinical samples. The physiological, neurochemical, and metabolic mechanisms underlying CES effects are currently unknown. Computational modeling suggests that electrical current administered with CES at the earlobes can reach cortical and subcortical regions at very low intensities associated with subthreshold neuromodulatory effects, and studies using electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) show some effects on alpha band EEG activity, and modulation of the default mode network during CES administration. One theory suggests that CES modulates brain stem (e.g., medulla), limbic (e.g., thalamus, amygdala), and cortical (e.g., prefrontal cortex) regions and increases relative parasympathetic to sympathetic drive in the autonomic nervous system. There is no direct evidence supporting this theory, but one of its assumptions is that CES may induce its effects by stimulating afferent projections of the vagus nerve, which provides parasympathetic signals to the cardiorespiratory and digestive systems. In our critical review of studies using CES in clinical and non-clinical populations, we found severe methodological concerns, including potential conflicts of interest, risk of methodological and analytic biases, issues with sham credibility, lack of blinding, and a severe heterogeneity of CES parameters selected and employed across scientists, laboratories, institutions, and studies. These limitations make it difficult to derive consistent or compelling insights from the extant literature, tempering enthusiasm for CES and its potential to alter nervous system activity or behavior in meaningful or reliable ways. The lack of compelling evidence also motivates well-designed and relatively high-powered experiments to assess how CES might modulate the physiological, affective, and cognitive responses to stress. Establishing reliable empirical links between CES administration and human performance is critical for supporting its prospective use during occupational training, operations, or recovery, ensuring reliability and robustness of effects, characterizing if, when, and in whom such effects might arise, and ensuring that any benefits of CES outweigh the risks of adverse events.
摘要:
颅电疗刺激(CES)是一种用于治疗几种临床疾病的神经调节工具,包括失眠,焦虑,和抑郁症。最近,有限数量的研究已经检查了CES改变情感,生理学,和健康的行为,非临床样本。生理,神经化学,目前尚不清楚CES效应背后的代谢机制。计算模型表明,CES在耳垂施加的电流可以以与阈值下神经调节效应相关的非常低的强度到达皮质和皮质下区域。使用脑电图(EEG)和功能磁共振成像(fMRI)的研究显示对α波段EEG活动的一些影响,和CES管理期间默认模式网络的调制。一种理论认为CES调节脑干(例如,髓质),边缘(例如,丘脑,杏仁核),和皮质(例如,前额叶皮层)区域,并增加自主神经系统中相对于交感神经的副交感神经驱动。没有直接的证据支持这个理论,但它的一个假设是CES可能通过刺激迷走神经的传入投射来诱导其效应,向心肺和消化系统提供副交感神经信号。在我们对临床和非临床人群使用CES的研究进行的严格审查中,我们发现了严重的方法论问题,包括潜在的利益冲突,方法和分析偏见的风险,虚假可信度的问题,缺乏盲目性,以及科学家选择和使用的CES参数的严重异质性,实验室,机构,和研究。这些限制使得很难从现有文献中获得一致或令人信服的见解,缓和对CES的热情及其以有意义或可靠的方式改变神经系统活动或行为的潜力。缺乏令人信服的证据也激发了精心设计和相对高功率的实验,以评估CES如何调节生理,情感,和对压力的认知反应。在CES管理与人类绩效之间建立可靠的经验联系对于支持其在职业培训期间的预期使用至关重要,操作,或恢复,确保效果的可靠性和鲁棒性,表征如果,when,这种影响可能出现在谁身上,并确保CES的任何好处都大于不良事件的风险。