Terzano Mario Giovanni, Smerieri Arianna, Del Felice Alessandra, Giglia Francesca, Palomba Vincenzo, Parrino Liborio
Department of Neuroscience, Sleep Disorders Center, University of Parma, Via Gramsci, 14, 43100 Parma, Italy.
Sleep Med. 2006 Dec;7(8):619-26. doi: 10.1016/j.sleep.2005.12.003. Epub 2006 Jun 5.
Narcolepsy is a sleep disorder with clinical symptoms attributed to a reduced activation of the arousal system. Cyclic alternating pattern (CAP) is the expression of rhythmic arousability during non-rapid eye movement (NREM) sleep. CAP parameters, arousals and conventional sleep measures were studied in narcoleptic patients with cataplexy.
Data were collected from all-night polysomnographic (PSG) recordings and the multiple sleep latency test (MSLT) on the intervening day of 25 drug-naive patients (10 males and 15 females; mean age: 34+/-16 years) after adaptation and exclusion of other sleep disorders. A group of 25 age- and gender-matched normal sleepers were selected as controls. Each PSG recording was subdivided into sleep cycles. Analysis of CAP included classification of A phases into subtypes A1, A2, and A3.
There was an increase in sleep period time mainly due to an increased wake time after sleep onset. REM latency was sharply reduced. The percentage of NREM sleep was slightly reduced and the balance between light sleep (S1+S2) and deep sleep (S3+S4) showed a curtailment of the former, while deep sleep was slightly increased. Excluding sleep cycles with sleep onset REM periods (SOREMPs), the duration of ordered sleep cycles was not different between narcoleptics and controls. The two groups showed similar values of arousal index, while CAP time, CAP rate, number of CAP cycles and of phase A subtypes (in particular subtypes A1) were significantly reduced in narcoleptic patients.
The reduced periods of CAP in narcoleptic NREM sleep could be the electroencephalographic (EEG) expression of a generally reduced arousability or an increased strength of sleep-promoting forces in the balance between sleep and arousal systems. This can explain some of the clinical correlates of the disorder, i.e. excessive sleepiness, short sleep latency and impaired attentive performances, even without any sign of arousal-induced sleep fragmentation.
发作性睡病是一种睡眠障碍，其临床症状归因于觉醒系统激活减少。周期性交替模式（CAP）是非快速眼动（NREM）睡眠期间节律性可唤醒性的表现。对伴有猝倒的发作性睡病患者的CAP参数、觉醒及传统睡眠指标进行了研究。
收集了25例未服用过药物的患者（10例男性和15例女性；平均年龄：34±16岁）在适应并排除其他睡眠障碍后的次日进行的整夜多导睡眠图（PSG）记录及多次睡眠潜伏期试验（MSLT）的数据。选取25例年龄和性别匹配的正常睡眠者作为对照组。每次PSG记录被细分为睡眠周期。CAP分析包括将A期分为A1、A2和A3亚型。
睡眠时间增加，主要是由于睡眠开始后的觉醒时间增加。快速眼动睡眠潜伏期显著缩短。NREM睡眠百分比略有降低，浅睡眠（S1+S2）与深睡眠（S3+S4）之间的平衡显示前者减少，而深睡眠略有增加。排除有睡眠开始时快速眼动期（SOREMPs）的睡眠周期后，发作性睡病患者与对照组之间有序睡眠周期的时长无差异。两组的觉醒指数值相似，而发作性睡病患者的CAP时间、CAP率、CAP周期数及A期亚型（尤其是A1亚型）的数量均显著降低。
发作性睡病患者NREM睡眠中CAP周期减少可能是觉醒系统总体可唤醒性降低或睡眠与觉醒系统平衡中促进睡眠力量增强的脑电图（EEG）表现。这可以解释该疾病的一些临床相关表现，即过度嗜睡、短睡眠潜伏期及注意力表现受损，即使没有任何觉醒引起的睡眠片段化迹象。
