PRISM Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
J Sleep Res. 2013 Apr;22(2):178-84. doi: 10.1111/jsr.12007. Epub 2012 Dec 6.
Hypocretin/orexin signalling varies among sleep-wake behaviours, impacts upon cardiovascular autonomic control and is impaired in patients with narcolepsy with cataplexy (NC). However, evidence concerning disturbed cardiovascular autonomic control in NC patients is contrasting, and limited mainly to waking behaviour. We thus investigated whether control of cardiovascular variability is altered in NC patients during wakefulness preceding sleep, light (1-2) and deep (3-4) stages of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. Polysomnographic recordings and finger blood pressure measurements were performed on nine drug-free male NC patients and nine matched healthy control subjects during spontaneous sleep-wake behaviour in a standardized laboratory environment. Indices of autonomic function were computed based on spontaneous fluctuations of systolic blood pressure (SBP) and heart period (HP). During wakefulness before sleep, NC patients showed significant decreases in indices of vagal HP modulation, cardiac baroreflex sensitivity and amplitude of central autonomic (feed-forward) cardiac control compared with control subjects. During NREM sleep, the negative correlation between HP and subsequent SBP values was greater in NC patients than in control subjects, suggesting a greater contribution of central autonomic commands to cardiac control. Collectively, these results provide preliminary evidence that autonomic control of cardiac variability by baroreflex and central autonomic (feed-forward) mechanisms is altered in NC patients during spontaneous sleep-wake behaviour, and particularly during wakefulness before sleep.
下丘脑分泌素/食欲素信号在睡眠-觉醒行为中存在差异，对心血管自主控制有影响，并且在猝倒性嗜睡症（narcolepsy with cataplexy，NC）患者中受损。然而，关于 NC 患者心血管自主控制紊乱的证据相互矛盾，且主要局限于清醒行为。因此，我们研究了在自然睡眠-觉醒过程中，NC 患者在睡眠前、1-2 级轻（light）睡眠和 3-4 级深（deep）非快速眼动（non-rapid eye movement，NREM）睡眠以及快速眼动（rapid eye movement，REM）睡眠期间，心血管变异性的控制是否发生改变。在标准化实验室环境中，对 9 名未服用药物的男性 NC 患者和 9 名匹配的健康对照者进行了多导睡眠图记录和手指血压测量，以记录其自发性睡眠-觉醒行为。基于收缩压（systolic blood pressure，SBP）和心率（heart period，HP）的自发性波动，计算了自主功能的指标。在睡眠前的清醒状态下，与对照组相比，NC 患者的迷走 HP 调制、心脏压力感受器敏感性和中枢自主（前馈）心脏控制的振幅等自主功能指标显著降低。在 NREM 睡眠期间，与对照组相比，NC 患者的 HP 与随后的 SBP 值之间的负相关更强，这表明中枢自主命令对心脏控制的贡献更大。总的来说，这些结果初步表明，在自然睡眠-觉醒行为中，尤其是在睡眠前的清醒状态下，NC 患者的心脏变异性的自主控制由压力感受器和中枢自主（前馈）机制发生改变。
