Abstract：
OBJECTIVE: Idiopathic/isolated REM-sleep behavior disorder (iRBD) often precedes the onset of synucleinopathies. Here, we investigated whether baseline resting-state EEG advanced spectral power and functional connectivity differ between iRBD patients who converted towards a synucleinopathy at follow-up and those who did not.
METHODS: Eighty-one participants with iRBD (66.89±6.91 years) underwent a baseline resting-state EEG recording, a neuropsychological assessment and a neurological examination. We estimated EEG power spectral density using standard analyses and derived spectral estimates of rhythmic and arrhythmic components. Global and pairwise EEG functional connectivity analyses were computed using the weighted phase-lag index (wPLI). Pixel-based permutation tests were used to compare groups.
RESULTS: After a mean follow-up of 5.01±2.76 years, 34 patients were diagnosed with a synucleinopathy (67.81±7.34 years) and 47 remained disease-free (65.53±7.09 years). Among patients who converted, 22 were diagnosed with Parkinson\'s disease and 12 with dementia with Lewy bodies. As compared to patients who did not convert, patients who converted exhibited at baseline higher relative theta standard power, steeper slopes of the arrhythmic component and higher theta rhythmic power mostly in occipital regions. Furthermore, patients who converted showed higher beta global wPLI but lower alpha wPLI between left temporal and occipital regions.
CONCLUSIONS: Analyses of resting-state EEG rhythmic and arrhythmic components and functional connectivity suggest an imbalanced excitatory-to-inhibitory activity within large-scale networks, which is associated with later development of a synucleinopathy in iRBD patients.
METHODS: Eighty-one participants with iRBD (66.89±6.91 years) underwent a baseline resting-state EEG recording, a neuropsychological assessment and a neurological examination. We estimated EEG power spectral density using standard analyses and derived spectral estimates of rhythmic and arrhythmic components. Global and pairwise EEG functional connectivity analyses were computed using the weighted phase-lag index (wPLI). Pixel-based permutation tests were used to compare groups.
RESULTS: After a mean follow-up of 5.01±2.76 years, 34 patients were diagnosed with a synucleinopathy (67.81±7.34 years) and 47 remained disease-free (65.53±7.09 years). Among patients who converted, 22 were diagnosed with Parkinson\'s disease and 12 with dementia with Lewy bodies. As compared to patients who did not convert, patients who converted exhibited at baseline higher relative theta standard power, steeper slopes of the arrhythmic component and higher theta rhythmic power mostly in occipital regions. Furthermore, patients who converted showed higher beta global wPLI but lower alpha wPLI between left temporal and occipital regions.
CONCLUSIONS: Analyses of resting-state EEG rhythmic and arrhythmic components and functional connectivity suggest an imbalanced excitatory-to-inhibitory activity within large-scale networks, which is associated with later development of a synucleinopathy in iRBD patients.
摘要：
目的：特发性/孤立性REM睡眠行为障碍（iRBD）通常先于突触核蛋白病的发作。这里,我们调查了在随访时转变为突触核蛋白病的iRBD患者与未转变为突触核蛋白病的iRBD患者之间基线静息状态EEG高级谱功率和功能连通性是否存在差异.
方法：81例iRBD患者（66.89±6.91岁）接受了基线静息状态脑电图记录，神经心理学评估和神经学检查.我们使用标准分析和节律和心律失常成分的频谱估计来估计EEG功率谱密度。使用加权相位滞后指数（wPLI）计算全局和成对EEG功能连通性分析。使用基于像素的置换测试来比较组。
结果：经过平均5.01±2.76年的随访，34例患者被诊断为突触核蛋白病（67.81±7.34年），47例患者保持无病（65.53±7.09年）。在转换的患者中，22例被诊断为帕金森病，12例被诊断为路易体痴呆。与没有转换的患者相比，转换的患者在基线时表现出更高的相对θ标准功率，主要在枕骨区域，心律失常成分的斜率较陡，而theta节律功率较高。此外，转换的患者在左颞区和枕区之间显示较高的β整体wPLI,但较低的αwPLI.
结论：对静息状态脑电图节律和心律失常成分以及功能连通性的分析表明，在大规模网络中，兴奋性到抑制性活动不平衡，这与iRBD患者的突触核蛋白病的后期发展有关。
方法：81例iRBD患者（66.89±6.91岁）接受了基线静息状态脑电图记录，神经心理学评估和神经学检查.我们使用标准分析和节律和心律失常成分的频谱估计来估计EEG功率谱密度。使用加权相位滞后指数（wPLI）计算全局和成对EEG功能连通性分析。使用基于像素的置换测试来比较组。
结果：经过平均5.01±2.76年的随访，34例患者被诊断为突触核蛋白病（67.81±7.34年），47例患者保持无病（65.53±7.09年）。在转换的患者中，22例被诊断为帕金森病，12例被诊断为路易体痴呆。与没有转换的患者相比，转换的患者在基线时表现出更高的相对θ标准功率，主要在枕骨区域，心律失常成分的斜率较陡，而theta节律功率较高。此外，转换的患者在左颞区和枕区之间显示较高的β整体wPLI,但较低的αwPLI.
结论：对静息状态脑电图节律和心律失常成分以及功能连通性的分析表明，在大规模网络中，兴奋性到抑制性活动不平衡，这与iRBD患者的突触核蛋白病的后期发展有关。
