Grigorescu Christina, Chalah Moussa A, Lefaucheur Jean-Pascal, Kümpfel Tania, Padberg Frank, Ayache Samar S, Palm Ulrich
Department of Psychiatry and Psychotherapy, Klinikum der Universität München, Munich, Germany.
EA 4391, Excitabilité nerveuse et thérapeutique, Université Paris-Est-Créteil, Créteil, France.
Front Neurol. 2020 Oct 15;11:545377. doi: 10.3389/fneur.2020.545377. eCollection 2020.
Multiple Sclerosis (MS) is a chronic inflammatory disease of the central nervous system. Cognitive impairment occurs in 40-65% of patients and could drastically affect their quality of life. Deficits could involve general cognition (e.g., attention and working memory) as well as social cognition. Transcranial direct current stimulation (tDCS), is a novel brain stimulation technique that has been assessed in the context of several neuropsychiatric symptoms, including those described in the context of MS. However, very rare trials have assessed tDCS effects on general cognition in MS, and none has tackled social cognition. The aim of this work was to assess tDCS effects on general and social cognition in MS. Eleven right-handed patients with MS received two blocks (bifrontal tDCS and sham, 2 mA, 20 min, anode/cathode over left/right prefrontal cortex) of 5 daily stimulations separated by a 3-week washout interval. Working memory and attention were, respectively, measured using N-Back Test (0-Back, 1-Back, and 2-Back) and Symbol Digit Modalities Test (SDMT) at the first and fifth day of each block and 1 week later. Social cognition was evaluated using Faux Pas Test and Eyes Test at baseline and 1 week after each block. Interestingly, accuracy of 1-Back test improved following sham but not active bifrontal tDCS. Therefore, active bifrontal tDCS could have impaired working memory via cathodal stimulation of the right prefrontal cortex. No significant tDCS effects were observed on social cognitive measures and SDMT. Admitting the small sample size and the learning (practice) effect that might arise from the repetitive administration of each task, the current results should be considered as preliminary and further investigations in larger patient samples are needed to gain a closer understanding of tDCS effects on cognition in MS.
多发性硬化症（MS）是一种中枢神经系统的慢性炎症性疾病。40%至65%的患者会出现认知障碍，这可能会严重影响他们的生活质量。认知缺陷可能涉及一般认知（如注意力和工作记忆）以及社会认知。经颅直流电刺激（tDCS）是一种新型脑刺激技术，已在多种神经精神症状的背景下进行了评估，包括在MS背景下描述的症状。然而，极少有试验评估tDCS对MS患者一般认知的影响，且没有一项试验涉及社会认知。这项研究的目的是评估tDCS对MS患者一般认知和社会认知的影响。11名右利手MS患者接受了两个疗程（双额叶tDCS和假刺激，2毫安，20分钟，阳极/阴极置于左/右前额叶皮质），每天刺激5次，中间间隔3周的洗脱期。在每个疗程的第一天和第五天以及1周后，分别使用N-回溯测试（0-回溯、1-回溯和2-回溯）和符号数字模态测试（SDMT）测量工作记忆和注意力。在基线以及每个疗程后1周，使用失言测试和眼神测试评估社会认知。有趣的是，假刺激后1-回溯测试的准确性提高了，但双额叶tDCS刺激后没有提高。因此，双额叶tDCS刺激可能通过阴极刺激右前额叶皮质损害了工作记忆。在社会认知测量和SDMT方面未观察到显著的tDCS效应。鉴于样本量小以及重复执行每个任务可能产生的学习（练习）效应，目前的结果应被视为初步结果，需要在更大的患者样本中进行进一步研究，以更深入地了解tDCS对MS患者认知的影响。
