Department of Psychiatry, Massachusetts General Hospital, Charlestown, MA 02129, United States.
J Psychiatr Res. 2010 Jan;44(2):112-20. doi: 10.1016/j.jpsychires.2009.06.011. Epub 2009 Aug 8.
We previously reported that patients with schizophrenia failed to demonstrate normal sleep-dependent improvement in motor procedural learning. Here, we tested whether this failure was associated with the duration of Stage 2 sleep in the last quartile of the night (S2q4) and with spindle activity during this epoch. Fourteen patients with schizophrenia and 15 demographically matched controls performed a motor sequence task (MST) before and after a night of polysomnographically monitored sleep. Patients showed no significant overnight task improvement and significantly less than controls, who did show significant improvement. While there were no group differences in overall sleep architecture, patients showed significant reductions in fast sigma frequency power (45%) and in spindle density (43%) during S2q4 sleep at the electrode proximal to the motor cortex controlling the hand that performed the MST. Although spindle activity did not correlate with overnight improvement in either group, S2q4 sleep duration in patients significantly correlated with the plateau level of overnight improvement seen at the end of the morning testing session, and slow wave sleep (SWS) duration correlated with the delay in reaching this plateau. SWS and S2q4 sleep each predicted the initial level of overnight improvement in schizophrenia, and their product explained 77% of the variance, suggesting that both sleep stages are necessary for consolidation. These findings replicate our prior observation of reduced sleep-dependent consolidation of motor procedural learning in schizophrenia and link this deficit to specific sleep stages. They provide further evidence that sleep is an important contributor to cognitive deficits in schizophrenia.
我们之前报道过精神分裂症患者在运动程序性学习方面未能表现出正常的睡眠依赖性改善。在这里,我们测试了这种失败是否与夜间最后四分之一阶段 2 睡眠(S2q4)的持续时间以及该时段的纺锤波活动有关。14 名精神分裂症患者和 15 名在人口统计学上匹配的对照组在经过一夜多导睡眠监测后进行了运动序列任务(MST)。患者在夜间没有显著的任务改善,明显低于对照组,对照组确实有显著的改善。虽然两组在总体睡眠结构上没有差异,但患者在靠近控制执行 MST 的手部运动皮层的电极处的 S2q4 睡眠中,快速西格玛频率功率(45%)和纺锤波密度(43%)显著降低。尽管在两组中,纺锤波活动都与夜间改善无关,但患者的 S2q4 睡眠时间与清晨测试结束时夜间改善的平台水平显著相关,而慢波睡眠(SWS)时间与达到该平台的延迟相关。SWS 和 S2q4 睡眠都预测了精神分裂症患者夜间改善的初始水平,它们的乘积解释了 77%的方差,表明这两个睡眠阶段对于巩固都是必要的。这些发现复制了我们之前观察到的精神分裂症患者运动程序性学习的睡眠依赖性巩固减少,并将这种缺陷与特定的睡眠阶段联系起来。它们进一步证明了睡眠是精神分裂症认知缺陷的一个重要贡献者。