Centre Leenaards de la Mémoire, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
Laboratory of Neuroimaging of Aging (LANVIE), University of Geneva, Geneva, Switzerland.
Alzheimers Res Ther. 2021 Oct 11;13(1):172. doi: 10.1186/s13195-021-00844-1.
Cognitive complaints in the absence of objective cognitive impairment, observed in patients with subjective cognitive decline (SCD), are common in old age. The first step to postpone cognitive decline is to use techniques known to improve cognition, i.e., cognitive enhancement techniques.We aimed to provide clinical recommendations to improve cognitive performance in cognitively unimpaired individuals, by using cognitive, mental, or physical training (CMPT), non-invasive brain stimulations (NIBS), drugs, or nutrients. We made a systematic review of CMPT studies based on the GRADE method rating the strength of evidence.CMPT have clinically relevant effects on cognitive and non-cognitive outcomes. The quality of evidence supporting the improvement of outcomes following a CMPT was high for metamemory; moderate for executive functions, attention, global cognition, and generalization in daily life; and low for objective memory, subjective memory, motivation, mood, and quality of life, as well as a transfer to other cognitive functions. Regarding specific interventions, CMPT based on repeated practice (e.g., video games or mindfulness, but not physical training) improved attention and executive functions significantly, while CMPT based on strategic learning significantly improved objective memory.We found encouraging evidence supporting the potential effect of NIBS in improving memory performance, and reducing the perception of self-perceived memory decline in SCD. Yet, the high heterogeneity of stimulation protocols in the different studies prevent the issuing of clear-cut recommendations for implementation in a clinical setting. No conclusive argument was found to recommend any of the main pharmacological cognitive enhancement drugs ("smart drugs", acetylcholinesterase inhibitors, memantine, antidepressant) or herbal extracts (Panax ginseng, Gingko biloba, and Bacopa monnieri) in people without cognitive impairment.Altogether, this systematic review provides evidence for CMPT to improve cognition, encouraging results for NIBS although more studies are needed, while it does not support the use of drugs or nutrients.
在主观认知下降（SCD）患者中，即使没有客观认知障碍，也会出现认知主诉，这在老年人群中很常见。延缓认知下降的第一步是使用已知可改善认知的技术，即认知增强技术。我们旨在通过认知、心理或身体训练（CMPT）、非侵入性脑刺激（NIBS）、药物或营养素，为改善认知正常个体的认知表现提供临床建议。我们根据 GRADE 方法对 CMPT 研究进行了系统评价，对证据强度进行了评分。CMPT 对认知和非认知结果具有临床相关影响。支持 CMPT 后改善结果的证据质量很高，涉及元记忆；中等，涉及执行功能、注意力、整体认知和日常生活中的概括能力；低，涉及客观记忆、主观记忆、动机、情绪和生活质量，以及对其他认知功能的转移。关于特定干预措施，基于重复练习的 CMPT（例如视频游戏或正念，但不包括体育锻炼）可显著改善注意力和执行功能，而基于策略学习的 CMPT 可显著改善客观记忆。我们发现有令人鼓舞的证据支持 NIBS 在改善记忆表现和减少 SCD 中自我感知记忆下降的潜在作用。然而，不同研究中刺激方案的高度异质性妨碍了在临床环境中实施的明确建议。没有确凿的证据表明推荐任何主要的药物认知增强药物（“聪明药”、乙酰胆碱酯酶抑制剂、美金刚、抗抑郁药）或草药提取物（人参、银杏叶和假马齿苋）用于认知正常的人群。总的来说，本系统评价为 CMPT 改善认知提供了证据，NIBS 的结果令人鼓舞，尽管还需要更多的研究，但不支持使用药物或营养素。
