Gu Jun, Li Da, Li Zhaohui, Guo Yuan, Qian Fuqiang, Wang Ying, Tang Li
Department of Mental Rehabilitation, Wuxi Mental Health Center, Wuxi, China.
Department of Neurorehabilitation, Wuxi Tongren Rehabilitation Hospital, Wuxi, China.
Front Neurosci. 2022 Feb 17;16:811403. doi: 10.3389/fnins.2022.811403. eCollection 2022.
This study aimed to investigate the efficacy of transcranial direct current stimulation (tDCS) on episodic memory in patients with mild cognitive impairment (MCI) and analyze the neural mechanism of tDCS therapy from the perspective of neuroelectrophysiological parameters.
Forty MCI patients were recruited and randomly divided into a sham group ( = 20) and a tDCS group ( = 20). Patients in the tDCS group were treated with a tDCS instrument for 20 min, once a day, for 5 days. Patients in the sham group were treated with sham stimulus. Montreal Cognitive Assessment Scale (MoCA), Wechsler Memory Scale (WMS), and event-related potential (ERP) (amplitude and latency of P300 wave) were comparatively assessed between the two groups at pre-treatment, 5 days and 4 weeks post-treatment points.
The two groups showed no significant difference in any of the assessed parameters at pre-treatment ( > 0.05). At 5 days post-treatment, memory quotient (MQ) score in the tDCS group significantly increased ( < 0.05), scores of picture memory, visual regeneration, logical memory, memory span, visual regeneration-delay, and logical memory-delay were significantly increased compared to pre-treatment ( < 0.01). The P300 amplitude significantly increased, and its latency significantly shortened ( < 0.01). Four weeks post-treatment, the scores of MQ and visual regeneration-delay in the tDCS group increased, compared to pre-treatment ( < 0.05); picture memory, visual regeneration, logical memory, memory span, and logical memory-delay improved ( < 0.01); the P300 amplitude increased, and its latency shortened ( < 0.01). At 5 days and 4 weeks post-treatment points, the tDCS group, compared with the sham group ( < 0.01), exhibited greater scores of MQ, picture memory, visual regeneration, logical memory, memory span, visual regeneration-delay, and logical memory-delay, increased P300 amplitude, and shortened P300 latency. Similarly, the tDCS group showed higher MQ scores at 5 days post-treatment ( < 0.05) and 4 weeks post-treatment ( < 0.01). Before treatment and after 5 days of treatment, P300 amplitude and latency difference were positively correlated with MQ difference ( < 0.05).
tDCS improved episodic memory in MCI patients, and the effect lasted for 4 weeks. Changes in ERP (P300) suggested that tDCS could promote changes in brain function.
本研究旨在探讨经颅直流电刺激（tDCS）对轻度认知障碍（MCI）患者情景记忆的疗效，并从神经电生理参数角度分析tDCS治疗的神经机制。
招募40例MCI患者，随机分为假刺激组（n = 20）和tDCS组（n = 20）。tDCS组患者使用tDCS仪器治疗20分钟，每天1次，共5天。假刺激组患者接受假刺激。在治疗前、治疗后5天和4周时，对两组患者进行蒙特利尔认知评估量表（MoCA）、韦氏记忆量表（WMS）及事件相关电位（ERP）（P300波的波幅和潜伏期）的比较评估。
治疗前两组患者各评估参数比较，差异均无统计学意义（P > 0.05）。治疗后5天，tDCS组记忆商数（MQ）评分显著升高（P < 0.05），图片记忆、视觉再生、逻辑记忆、记忆广度、视觉再生延迟及逻辑记忆延迟评分较治疗前显著升高（P < 0.01）。P300波幅显著升高，潜伏期显著缩短（P < 0.01）。治疗后4周，tDCS组MQ及视觉再生延迟评分较治疗前升高（P < 0.05）；图片记忆、视觉再生、逻辑记忆、记忆广度及逻辑记忆延迟评分改善（P < 0.01）；P300波幅升高，潜伏期缩短（P < 0.01）。治疗后5天和4周时，tDCS组与假刺激组相比（P < 0.01），MQ、图片记忆、视觉再生、逻辑记忆、记忆广度、视觉再生延迟及逻辑记忆延迟评分更高，P300波幅升高，潜伏期缩短。同样，tDCS组在治疗后5天（P < 0.05）和4周（P < 0.01）时MQ评分更高。治疗前及治疗5天后，P300波幅和潜伏期差值与MQ差值呈正相关（P < 0.05）。
tDCS改善了MCI患者的情景记忆，且效果持续4周。ERP（P300）的变化提示tDCS可促进脑功能改变。
