Ayanampudi V, Kumar V, Krishnan A, Walker M P, Ivry R B, Knight R T, Gurumoorthy R
StimScience Inc., Berkeley, CA, United States.
Department of Psychology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States.
Front Hum Neurosci. 2023 Jan 10;16:1066453. doi: 10.3389/fnhum.2022.1066453. eCollection 2022.
Insufficient sleep is a major health issue. Inadequate sleep is associated with an array of poor health outcomes, including cardiovascular disease, diabetes, obesity, certain forms of cancer, Alzheimer's disease, depression, anxiety, and suicidality. Given concerns with typical sedative hypnotic drugs for treating sleep difficulties, there is a compelling need for alternative interventions. Here, we report results of a non-invasive electrical brain stimulation approach to optimizing sleep involving transcranial alternating current stimulation (tACS). A total of 25 participants (mean age: 46.3, S.D. ± 12.4, 15 females) were recruited for a null-stimulation controlled (Control condition), within subjects, randomized crossed design, that included two variants of an active condition involving 15 min pre-sleep tACS stimulation. To evaluate the impact on sleep quality, the two active tACS stimulation conditions were designed to modulate sleep-dependent neural activity in the theta/alpha frequency bands, with both stimulation types applied to all subjects in separate sessions. The first tACS condition used a fixed stimulation pattern across all participants, a pattern composed of stimulation at 5 and 10 Hz. The second tACS condition used a personalized stimulation approach with the stimulation frequencies determined by each individual's peak EEG frequencies in the 4-6 Hz and 9-11 Hz bands. Personalized tACS stimulation increased sleep quantity (duration) by 22 min compared to a Control condition ( = 0.04), and 19 min compared to Fixed tACS stimulation ( = 0.03). Fixed stimulation did not significantly increase sleep duration compared to Control (mean: 3 min; = 0.75). For sleep onset, the Personalized tACS stimulation resulted in reducing the onset by 28% compared to the Fixed tACS stimulation (6 min faster, = 0.02). For a Poor Sleep sub-group ( = 13) categorized with Clinical Insomnia and a high insomnia severity, Personalized tACS stimulation improved sleep duration by 33 min compared to Fixed stimulation ( = 0.02), and 30 min compared to Control condition ( < 0.1). Together, these results suggest that Personalized stimulation improves sleep quantity and time taken to fall asleep relative to Control and Fixed stimulation providing motivation for larger-scale trials for Personalized tACS as a sleep therapeutic, including for those with insomnia.
睡眠不足是一个主要的健康问题。睡眠不足与一系列不良健康后果相关，包括心血管疾病、糖尿病、肥胖症、某些类型的癌症、阿尔茨海默病、抑郁症、焦虑症和自杀倾向。鉴于对治疗睡眠困难的典型镇静催眠药物的担忧，迫切需要替代干预措施。在此，我们报告了一种通过经颅交流电刺激（tACS）优化睡眠的非侵入性脑电刺激方法的结果。总共招募了25名参与者（平均年龄：46.3岁，标准差±12.4，15名女性），采用无刺激对照（对照条件）、受试者内随机交叉设计，其中包括两种主动条件变体，涉及睡前15分钟的tACS刺激。为了评估对睡眠质量的影响，两种主动tACS刺激条件旨在调节θ/α频段中与睡眠相关的神经活动，两种刺激类型分别在不同时段应用于所有受试者。第一种tACS条件在所有参与者中使用固定的刺激模式，该模式由5赫兹和10赫兹的刺激组成。第二种tACS条件采用个性化刺激方法，刺激频率由每个人在4 - 6赫兹和9 - 11赫兹频段的脑电图峰值频率确定。与对照条件相比，个性化tACS刺激使睡眠量（持续时间）增加了22分钟（P = 0.04），与固定tACS刺激相比增加了19分钟（P = 0.03）。与对照相比，固定刺激并未显著增加睡眠时间（平均：3分钟；P = 0.75）。对于入睡情况，与固定tACS刺激相比，个性化tACS刺激使入睡时间减少了28%（快6分钟，P = 0.02）。对于被归类为临床失眠且失眠严重程度较高的睡眠不佳亚组（n = 13），与固定刺激相比，个性化tACS刺激使睡眠时间增加了33分钟（P = 0.02），与对照条件相比增加了30分钟（P < 0.1）。总之，这些结果表明，相对于对照和固定刺激，个性化刺激改善了睡眠量和入睡时间，为将个性化tACS作为一种睡眠治疗方法进行更大规模试验提供了动力，包括针对失眠患者。
