Gong Si-Yi, Shen Yun, Gu Han-Ying, Zhuang Sheng, Fu Xiang, Wang Qiao-Jun, Mao Cheng-Jie, Hu Hua, Dai Yong-Ping, Liu Chun-Feng
Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, People's Republic of China.
Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, 215123, People's Republic of China.
Nat Sci Sleep. 2022 Mar 11;14:407-418. doi: 10.2147/NSS.S354063. eCollection 2022.
Idiopathic rapid eye movement sleep behavior disorder (iRBD) is the prodromal marker of α-synuclein degeneration with markedly high predictive value. We aim to evaluate the value of electroencephalography (EEG) data during rapid eye movement (REM) sleep and subjective RBD severity in predicting the conversion to neurodegenerative diseases in iRBD patients.
At the baseline, iRBD patients underwent clinical assessment and video-polysomnography (PSG). Relative spectral power for nine frequency bands during phasic and tonic REM sleep in three regions of interest, slow-to-fast ratios, clinical and PSG variables were estimated and compared between iRBD patients who converted to neurodegenerative diseases (iRBD-C) and iRBD patients who remained disease-free (iRBD-NC). Receiver operating characteristic (ROC) curves evaluated the predictive performance of slow-to-fast ratios, and subjective RBD severity as assessed with RBD Questionnaire-Hong Kong.
Twenty-two (33.8%) patients eventually developed neurodegenerative diseases. The iRBD-C group showed shorter total sleep time ( < 0.001), lower stage 2 sleep percentage ( = 0.044), more periodic leg-movement-related arousal index ( = 0.004), increased tonic chin electromyelographic activity ( = 0.040) and higher REM density in the third REM episode ( = 0.034) than the iRBD-NC group. EEG spectral power analyses revealed that iRBD phenoconverters showed significantly higher delta and lower alpha power, especially in central and occipital regions during the phasic REM state compared to the iRBD-NC group. Significantly higher slow-to-fast ratios were observed in a more generalized way during the phasic state in the iRBD-C group compared to the iRBD-NC group. ROC analyses of the slowing ratio in occipital areas during phasic REM sleep yielded an area under the curve of 0.749 ( = 0.001), while no significant predictive value of subjective RBD severity was observed.
Our study shows that EEG slowing, especially in a more generalized manner during the phasic period, may be a promising marker in predicting phenoconversion in iRBD, rather than subjective RBD severity.
特发性快速眼动睡眠行为障碍（iRBD）是α-突触核蛋白变性的前驱标志物，具有显著的高预测价值。我们旨在评估快速眼动（REM）睡眠期间的脑电图（EEG）数据和主观RBD严重程度在预测iRBD患者向神经退行性疾病转化中的价值。
在基线时，iRBD患者接受临床评估和视频多导睡眠图（PSG）检查。估计并比较了iRBD患者中转化为神经退行性疾病的患者（iRBD-C）和未患疾病的iRBD患者（iRBD-NC）在三个感兴趣区域的快速眼动睡眠期和紧张性快速眼动睡眠期九个频段的相对频谱功率、慢波与快波比值、临床和PSG变量。采用受试者操作特征（ROC）曲线评估慢波与快波比值以及用香港RBD问卷评估的主观RBD严重程度的预测性能。
22名（33.8%）患者最终发展为神经退行性疾病。与iRBD-NC组相比，iRBD-C组的总睡眠时间更短（<0.001）、第二阶段睡眠百分比更低（=0.044）、周期性腿部运动相关唤醒指数更高（=0.004）、紧张性颏肌肌电图活动增加（=0.040）以及第三个快速眼动期的快速眼动密度更高（=0.034）。脑电图频谱功率分析显示，与iRBD-NC组相比，iRBD表型转化者在快速眼动睡眠期的δ波功率显著更高，α波功率更低，尤其是在中央和枕叶区域在快速眼动相期间。与iRBD-NC组相比，iRBD-C组在快速眼动相期间以更普遍的方式观察到显著更高的慢波与快波比值。对快速眼动睡眠期枕叶区域的慢波比值进行ROC分析得出曲线下面积为0.749（=0.001），而未观察到主观RBD严重程度具有显著预测价值。
我们的研究表明，脑电图慢波，尤其是在快速眼动相期间以更普遍的方式出现，可能是预测iRBD表型转化的一个有前景的标志物，而不是主观RBD严重程度。
