Nicholas Christian L, Sullivan Edith V, Pfefferbaum Adolf, Trinder John, Colrain Ian M
Department of Psychology, University of Melbourne, Melbourne, Australia.
J Sleep Res. 2002 Sep;11(3):247-53. doi: 10.1046/j.1365-2869.2002.00298.x.
Normal aging is associated with a reduction in the probability that an auditory stimulus will evoke a K-complex during sleep. Additional concomitants of aging are a reduction in the amplitude of the K-complex-related N550, an augmentation of the P2 component and the appearance of a long-lasting positivity (LLP) in the auditory evoked potential. Normal aging is also associated with a dramatic reduction in slow wave sleep (SWS) and a reduction in the volume of cortical gray matter, particularly in the frontal and prefrontal regions of the brain. As in aging, alcoholism is associated with reductions in both cortical gray matter and SWS. It can, therefore, be hypothesized that alcoholics would show similar evoked potential changes to those seen in aging. To test this hypothesis, we studied seven middle-aged abstinent long-term alcoholics and eight age-matched normal controls. Each subject spent one night in the laboratory. Electroencephalogram (EEG) was recorded from six midline scalp sites and auditory stimuli were presented during stage 2 non-rapid eye movement sleep. N550 amplitude in the K-complex average was lower in the alcoholics as compared with controls as was the likelihood of K-complex production. No differences were noted in either amplitude or latency of the P2 or N350 components, and both groups displayed a prominent LLP potential. The pattern of reduced K-complex production and N550 amplitude in alcoholics as compared with age-matched controls is consistent with an hypothesized association between atrophy of the frontal lobes and reductions in SWS and K-complexes. The finding also suggests that the evoked K-complex may be a relatively simple measure of the effect of alcoholism on EEG during sleep.
正常衰老与睡眠期间听觉刺激诱发K复合波的概率降低有关。衰老的其他伴随现象包括与K复合波相关的N550波幅降低、P2成分增强以及听觉诱发电位中出现持久正波（LLP）。正常衰老还与慢波睡眠（SWS）显著减少以及皮质灰质体积减少有关，尤其是在大脑的额叶和前额叶区域。与衰老一样，酗酒也与皮质灰质和SWS减少有关。因此，可以假设酗酒者会表现出与衰老中所见类似的诱发电位变化。为了验证这一假设，我们研究了7名中年戒酒的长期酗酒者和8名年龄匹配的正常对照者。每位受试者在实验室度过一晚。从头皮中线的六个部位记录脑电图（EEG），并在非快速眼动睡眠2期期间呈现听觉刺激。与对照组相比，酗酒者K复合波平均中的N550波幅较低，K复合波产生的可能性也较低。P2或N350成分的波幅或潜伏期均未发现差异，两组均显示出明显的LLP电位。与年龄匹配的对照组相比，酗酒者K复合波产生减少和N550波幅降低的模式与额叶萎缩、SWS减少和K复合波减少之间的假设关联一致。这一发现还表明，诱发的K复合波可能是酗酒对睡眠期间脑电图影响的一种相对简单的测量方法。
