Svanborg E, Guilleminault C
Department of Clinical Neurophysiology, Karolinska Institute div. Söder Hospital, Stockholm, Sweden.
Sleep. 1996 Apr;19(3):248-54.
To study the effect of transient, apnea-induced hypoxemia on electrocortical activity, five patients with severe obstructive sleep apnea syndrome (OSAS) were investigated during nocturnal sleep. Polysomnographic and simultaneous digitized electro encephalographic (EEG) recordings for topographic and compressed spectral array analysis were made. The EEG recordings were timed exactly to respiratory events. During nonrapid eye movement (NREM) apnea, delta band amplitude increased, starting on average 13 seconds after the apnea onset. Average differences were 268% between initial and maximal values and 202% between initial and final values. In contrast, significant increases in delta amplitudes between the onset and end of REM apneas did not occur, although some caused deep oxygen desaturations. Changes in delta activity were not correlated to NREM apnea duration or degree of desaturation. These results indicate that the increased delta activity during NREM apneas may not be caused by arterial hypoxemia. It could instead be due to either an arousal mechanism, since arousals may be preceded by slow waves in EEG, or to a breakthrough of slow-wave-sleep activity. The sleep disturbance in severe OSAS may create such a propensity for slow-wave sleep that stages pass much more rapidly than in normal persons.
为研究短暂性呼吸暂停诱发的低氧血症对皮质电活动的影响，对5例重度阻塞性睡眠呼吸暂停综合征（OSAS）患者进行了夜间睡眠期间的调查。进行了多导睡眠图检查以及同步数字化脑电图（EEG）记录，用于地形图和压缩谱阵分析。EEG记录与呼吸事件精确同步。在非快速眼动（NREM）期呼吸暂停期间，δ波频段振幅增加，平均在呼吸暂停开始后13秒开始。初始值与最大值之间的平均差异为268%，初始值与最终值之间的平均差异为202%。相比之下，尽管一些快速眼动（REM）期呼吸暂停会导致严重的氧饱和度下降，但在REM期呼吸暂停开始和结束之间，δ波振幅没有显著增加。δ波活动的变化与NREM期呼吸暂停持续时间或氧饱和度下降程度无关。这些结果表明，NREM期呼吸暂停期间δ波活动增加可能不是由动脉低氧血症引起的。相反，这可能是由于觉醒机制，因为觉醒之前脑电图中可能会出现慢波，或者是由于慢波睡眠活动的突破。重度OSAS中的睡眠障碍可能会导致慢波睡眠的这种倾向，使得各阶段的进展比正常人快得多。
