Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy; Neurology Unit, Department of Neurological and Vision Sciences, ASST Spedali Civili, Brescia, Italy.
Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
Brain Stimul. 2021 May-Jun;14(3):531-540. doi: 10.1016/j.brs.2021.03.007. Epub 2021 Mar 21.
To assess whether exposure to non-invasive brain stimulation with transcranial alternating current stimulation at γ frequency (γ-tACS) applied over Pz (an area overlying the medial parietal cortex and the precuneus) can improve memory and modulate cholinergic transmission in mild cognitive impairment due to Alzheimer's disease (MCI-AD).
In this randomized, double-blind, sham controlled, crossover pilot study, participants were assigned to a single 60 min treatment with exposure to γ-tACS over Pz or sham tACS. Each subject underwent a clinical evaluation including assessment of episodic memory pre- and post-γ-tACS or sham stimulation. Indirect measures of cholinergic transmission evaluated using transcranial magnetic stimulation (TMS) pre- and post-γ-tACS or sham tACS were evaluated.
Twenty MCI-AD participants completed the study. No tACS-related side effects were observed, and the intervention was well tolerated in all participants. We observed a significant improvement at the Rey auditory verbal learning (RAVL) test total recall (5.7 [95% CI, 4.0 to 7.4], p < 0.001) and long delayed recall scores (1.3 [95% CI, 0.4 to 2.1], p = 0.007) after γ-tACS but not after sham tACS. Face-name associations scores improved during γ-tACS (4.3 [95% CI, 2.8 to 5.8], p < 0.001) but not after sham tACS. Short latency afferent inhibition, an indirect measure of cholinergic transmission evaluated with TMS, increased only after γ-tACS (0.31 [95% CI, 0.24 to 0.38], p < 0.001) but not after sham tACS.
exposure to γ-tACS over Pz showed a significant improvement of memory performances, along with restoration of intracortical connectivity measures of cholinergic neurotransmission, compared to sham tACS.
评估经颅交流电刺激（transcranial alternating current stimulation，tACS）γ 频段（γ-tACS）刺激 Pz（覆盖内侧顶叶皮层和楔前叶的区域）是否可改善阿尔茨海默病相关轻度认知障碍（Alzheimer's disease，MCI-AD）患者的记忆，并调节胆碱能传递。
在这项随机、双盲、假刺激对照、交叉先导研究中，参与者被分配至单次 60 分钟 Pz 区γ-tACS 或假 tACS 暴露治疗。所有受试者均接受临床评估，包括γ-tACS 或假刺激前后的情景记忆评估。γ-tACS 或假 tACS 前后采用经颅磁刺激（transcranial magnetic stimulation，TMS）评估间接的胆碱能传递测量。
20 名 MCI-AD 参与者完成了这项研究。未观察到 tACS 相关的不良反应，所有参与者均能很好地耐受干预。我们观察到，与假 tACS 相比，γ-tACS 后 Rey 听觉言语学习测试（Rey auditory verbal learning test，RAVL）总回忆（5.7[95%置信区间，4.0 至 7.4]，p<0.001）和长延迟回忆评分（1.3[95%置信区间，0.4 至 2.1]，p=0.007）显著改善。γ-tACS 后面孔-名字关联测试（face-name associations test）评分改善（4.3[95%置信区间，2.8 至 5.8]，p<0.001），但假 tACS 后无改善。用 TMS 评估的胆碱能传递的短潜伏期传入抑制，一种间接的测量指标，仅在γ-tACS 后增加（0.31[95%置信区间，0.24 至 0.38]，p<0.001），但假 tACS 后无增加。
与假 tACS 相比，γ-tACS 刺激 Pz 可显著改善记忆表现，并恢复胆碱能神经传递的皮质内连接测量。
