Sleep Medicine Unit, Neurocenter of Southern Switzerland, Ospedale Civico, Lugano, Switzerland; Faculty of Biomedical Sciences, University of Southern Switzerland, Lugano, Switzerland; University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.
Institute of Computational Life Sciences, Zurich University of Applied Sciences, Wädenswil, Switzerland.
Cortex. 2022 Oct;155:62-74. doi: 10.1016/j.cortex.2022.05.021. Epub 2022 Jul 22.
Confusional arousal is the milder expression of a family of disorders known as Disorders of Arousal (DOA) from non-REM sleep. These disorders are characterized by recurrent abnormal behaviors that occur in a state of reduced awareness for the external environment. Despite frequent amnesia for the nocturnal events, when actively probed, patients are able to report vivid hallucinatory/dream-like mental imagery. Traditional (low-density) scalp and stereo-electroencephalographic (EEG) recordings previously showed a pathological admixture of slow oscillations typical of NREM sleep and wake-like fast-mixed frequencies during these phenomena. However, our knowledge about the specific neural EEG dynamics over the entire brain is limited. We collected 2 consecutive in-laboratory sleep recordings using high-density (hd)-EEG (256 vertex-referenced geodesic system) coupled with standard video-polysomnography (v-PSG) from a 12-year-old drug-naïve and otherwise healthy child with a long-lasting history of sleepwalking. Source power topography and functional connectivity were computed during 20 selected confusional arousal episodes (from -6 to +18 sec after motor onset), and during baseline slow wave sleep preceding each episode (from - 3 to -2 min before onset). We found a widespread increase in slow wave activity (SWA) theta, alpha, beta, gamma power, associated with a parallel decrease in the sigma range during behavioral episodes compared to baseline sleep. Bilateral Broadman area 7 and right Broadman areas 39 and 40 were relatively spared by the massive increase in SWA power. Functional SWA connectivity analysis revealed a drastic increase in the number and complexity of connections from baseline sleep to full-blown episodes, that mainly involved an increased out-flow from bilateral fronto-medial prefrontal cortex and left temporal lobe to other cortical regions. These effects could be appreciated in the 6 sec window preceding behavioral onset. Overall, our results support the idea that DOA are the expression of peculiar brain states, compatible with a partial re-emergence of consciousness.
意识模糊性觉醒是一组被称为非快速眼动睡眠觉醒障碍（DOA）的障碍的轻度表现。这些障碍的特征是反复发作的异常行为，发生在对外界环境意识降低的状态下。尽管患者对夜间事件经常健忘，但在积极探查时，他们能够报告生动的幻觉/梦境般的心理意象。传统（低密度）头皮和立体脑电图（EEG）记录先前显示，在这些现象中，存在典型的非快速眼动睡眠慢波和类似于觉醒的快速混合频率的病理性混合。然而，我们对整个大脑特定的神经 EEG 动力学的了解是有限的。我们使用高密度（hd）-EEG（256 个顶点参考测地线系统）结合标准视频多导睡眠图（v-PSG）从一名 12 岁的、无药物史且无其他健康问题的、长期梦游的儿童中连续采集了 2 次实验室睡眠记录。在 20 次选定的意识模糊性觉醒发作期间（从运动发作后-6 到+18 秒）和每次发作前的基线慢波睡眠期间（发作前-3 到-2 分钟），计算了源功率地形图和功能连接。我们发现，与基线睡眠相比，在行为发作期间，慢波活动（SWA）θ、α、β、γ功率广泛增加，而西格玛范围的功率平行下降。双侧 Broadman 区 7 和右侧 Broadman 区 39 和 40 相对免受 SWA 功率大幅增加的影响。功能 SWA 连接分析显示，从基线睡眠到完全发作的连接数量和复杂性急剧增加，主要涉及双侧额内侧前额叶皮层和左颞叶到其他皮质区域的传出增加。这些效应可以在行为发作前的 6 秒窗口中得到体现。总的来说，我们的结果支持这样一种观点，即 DOA 是特定脑状态的表现，与意识的部分重新出现兼容。
