Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
Sleep. 2023 Apr 12;46(4). doi: 10.1093/sleep/zsac165.
Excessive daytime sleepiness (EDS) is a common and devastating symptom in Parkinson disease (PD), but surprisingly most studies showed that EDS is independent from nocturnal sleep disturbance measured with polysomnography. Quantitative electroencephalography (EEG) may reveal additional insights by measuring the EEG hallmarks of non-rapid eye movement (NREM) sleep, namely slow waves and spindles. Here, we tested the hypothesis that EDS in PD is associated with nocturnal sleep disturbance revealed by quantitative NREM sleep EEG markers.
Patients with PD (n = 130) underwent polysomnography followed by spectral analysis to calculate spindle frequency activity, slow-wave activity (SWA), and overnight SWA decline, which reflects the dissipation of homeostatic sleep pressure. We used the Epworth Sleepiness Scale (ESS) to assess subjective daytime sleepiness and define EDS (ESS > 10). All examinations were part of an evaluation for deep brain stimulation.
Patients with EDS (n = 46) showed reduced overnight decline of SWA (p = 0.036) and reduced spindle frequency activity (p = 0.032) compared with patients without EDS. Likewise, more severe daytime sleepiness was associated with reduced SWA decline (ß= -0.24 p = 0.008) and reduced spindle frequency activity (ß= -0.42, p < 0.001) across all patients. Reduced SWA decline, but not daytime sleepiness, was associated with poor sleep quality and continuity at polysomnography.
Our data suggest that daytime sleepiness in PD patients is associated with sleep disturbance revealed by quantitative EEG, namely reduced overnight SWA decline and reduced spindle frequency activity. These findings could indicate that poor sleep quality, with incomplete dissipation of homeostatic sleep pressure, may contribute to EDS in PD.
日间过度嗜睡（EDS）是帕金森病（PD）的一种常见且严重的症状，但令人惊讶的是，大多数研究表明，EDS 与多导睡眠图测量的夜间睡眠障碍无关。定量脑电图（EEG）通过测量非快速眼动（NREM）睡眠的 EEG 标志，即慢波和纺锤波，可能会提供更多的见解。在这里，我们检验了这样一个假设，即 PD 中的 EDS 与定量 NREM 睡眠 EEG 标志物揭示的夜间睡眠障碍有关。
130 例 PD 患者接受多导睡眠图检查，随后进行频谱分析以计算纺锤波频率活动、慢波活动（SWA）和夜间 SWA 下降，这反映了稳态睡眠压力的消散。我们使用 Epworth 嗜睡量表（ESS）评估主观日间嗜睡并定义 EDS（ESS > 10）。所有检查均为深部脑刺激评估的一部分。
与无 EDS 的患者相比，有 EDS 的患者（n = 46）的夜间 SWA 下降幅度较小（p = 0.036），纺锤波频率活动较低（p = 0.032）。同样，日间嗜睡越严重，SWA 下降幅度越低（β= -0.24，p = 0.008），纺锤波频率活动越低（β= -0.42，p < 0.001）。在所有患者中，SWA 下降幅度降低，而不是日间嗜睡，与多导睡眠图上的睡眠质量和连续性差有关。
我们的数据表明，PD 患者的日间嗜睡与定量 EEG 揭示的睡眠障碍有关，即夜间 SWA 下降幅度降低和纺锤波频率活动降低。这些发现可能表明，睡眠质量差，稳态睡眠压力未完全消散，可能导致 PD 中的 EDS。
