Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
Biomedical Knowledge Engineering Laboratory, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
Sci Rep. 2020 Feb 11;10(1):2354. doi: 10.1038/s41598-020-59264-0.
Nitrous oxide, the least potent inhalation anesthetic, is widely used for conscious sedation. Recently, it has been reported that the occurrence of anesthetic-induced loss of consciousness decreases the interconnection between brain regions, resulting in brain network changes. However, few studies have investigated these changes in conscious sedation using nitrous oxide. Therefore, the present study aimed to use graph theory to analyze changes in brain networks during nitrous oxide sedation. Participants were 20 healthy volunteers (10 men and 10 women, 20-40 years old) with no history of systemic disease. We acquired electroencephalogram (EEG) recordings of 32 channels during baseline, nitrous oxide inhalation sedation, and recovery. EEG epochs from the baseline and the sedation state (50% nitrous oxide) were extracted and analyzed with the network connection parameters of graph theory. Analysis of 1/f dynamics, revealed a steeper slope while in the sedation state than during the baseline. Network connectivity parameters showed significant differences between the baseline and sedation state, in delta, alpha1, alpha2, and beta2 frequency bands. The most pronounced differences in functional distance during nitrous oxide sedation were observed in the alpha1 and alpha2 frequency bands. Change in 1/f dynamics indicates that changes in brain network systems occur during nitrous oxide administration. Changes in network parameters imply that nitrous oxide interferes with the efficiency of information integration in the frequency bands important for cognitive processes and attention tasks. Alteration of brain network during nitrous oxide administration may be associated to the sedative mechanism of nitrous oxide.
氧化亚氮是一种效力最低的吸入性麻醉剂，被广泛用于清醒镇静。最近有报道称，麻醉诱导的意识丧失会减少脑区之间的连接，导致脑网络发生变化。然而，很少有研究使用氧化亚氮来研究这种意识镇静状态下的变化。因此，本研究旨在使用图论分析氧化亚氮镇静期间脑网络的变化。参与者为 20 名健康志愿者（10 名男性，10 名女性，年龄 20-40 岁），均无系统性疾病史。我们在基线、氧化亚氮吸入镇静和恢复期间采集了 32 通道的脑电图（EEG）记录。从基线和镇静状态（50%氧化亚氮）提取 EEG 时段，并使用图论的网络连接参数进行分析。1/f 动力学分析显示，镇静状态下的斜率比基线时更陡。网络连接参数显示，在 delta、alpha1、alpha2 和 beta2 频段，基线和镇静状态之间存在显著差异。在氧化亚氮镇静期间，功能距离的变化在 alpha1 和 alpha2 频段最为明显。1/f 动力学的变化表明，在氧化亚氮给药期间，脑网络系统发生了变化。网络参数的变化意味着氧化亚氮干扰了对认知过程和注意任务重要的频率带中信息整合的效率。氧化亚氮给药期间脑网络的改变可能与氧化亚氮的镇静机制有关。
