Darchia Nato, Campbell Ian G, Feinberg Irwin
University of California, Davis 95616, USA.
Sleep. 2003 Dec 15;26(8):973-7. doi: 10.1093/sleep/26.8.973.
While there is general agreement on the age changes in non-rapid eye movement sleep, there is conflicting evidence on whether eye movement density (EMD) in rapid eye movement sleep is affected by aging. We therefore performed computer measurement of EMD in young and elderly normal subjects.
Sleep electroencephalogram and electrooculogram were recorded in each subject on 4 nonconsecutive baseline nights. Eye movement density in the elderly subjects was compared to that in young adults.
A sleep research laboratory with 4 separate bedrooms.
Not applicable.
Subjects were 19 young normal adults and 19 elderly normal adults.
Digitized electrooculograms were analyzed with the extensively validated zero-cross period-amplitude module of PASS PLUS software. The EMD was measured as 0.3 to 2 Hz integrated amplitude per 20-second stage of rapid eye movement sleep. Eye-movement incidence was the number of half waves. Eye-movement amplitude was the sum of peak-trough excursions (curve length) in the average half wave. We also counted visually the number of 2-second epochs with eye movements for 1 baseline night in both groups. The EMD in the elderly subjects was substantially and significantly lower than in the young subjects. Visual scoring of EMD on 1 baseline night confirmed the statistically significant difference between age groups. Period-amplitude analysis revealed that a lower eye-movement incidence rather than reduced amplitude caused the lower EMD in the elderly. The EMD was significantly correlated within subjects across the nonconsecutive baseline nights in both groups; in both, subjects' EMD average across 2 nights provided a correlation greater than .90 with the 4-night mean.
The incidence of eye movements during rapid eye movement sleep is substantially reduced in the elderly. We hypothesize that this reduction is due to degenerative (aging) rather than developmental brain changes. The correlation analysis indicates that EMD is a reasonably stable individual trait in both young and elderly adults. These results encourage normative studies of EMD over a wider age span and continued exploration of the relation of EMD to cognitive function in the elderly.
虽然对于非快速眼动睡眠中的年龄变化已达成普遍共识，但关于快速眼动睡眠中的眼动密度（EMD）是否受衰老影响，证据存在冲突。因此，我们对年轻和老年正常受试者进行了眼动密度的计算机测量。
在4个不连续的基线夜晚记录每个受试者的睡眠脑电图和眼电图。将老年受试者的眼动密度与年轻成年人的进行比较。
一个有4个独立卧室的睡眠研究实验室。
不适用。
受试者为19名年轻正常成年人和19名老年正常成年人。
使用经过广泛验证的PASS PLUS软件的过零周期 - 振幅模块分析数字化眼电图。眼动密度的测量方法是快速眼动睡眠每20秒阶段的0.3至2赫兹积分振幅。眼动发生率是半波的数量。眼动振幅是平均半波中峰 - 谷偏移（曲线长度）的总和。我们还在两组中对1个基线夜晚有眼动的2秒时段进行了视觉计数。老年受试者的眼动密度显著低于年轻受试者。在1个基线夜晚对眼动密度进行视觉评分证实了年龄组之间的统计学显著差异。周期 - 振幅分析表明，老年受试者眼动密度较低是由于眼动发生率较低而非振幅降低所致。在两组中，受试者在不连续的基线夜晚的眼动密度在个体内显著相关；在两组中，受试者2晚的眼动密度平均值与4晚平均值的相关性均大于0.90。
老年人快速眼动睡眠期间的眼动发生率显著降低。我们推测这种降低是由于退行性（衰老）而非发育性脑变化所致。相关性分析表明，眼动密度在年轻和老年成年人中都是一个相当稳定的个体特征。这些结果鼓励在更广泛的年龄范围内进行眼动密度的规范性研究，并继续探索眼动密度与老年人认知功能的关系。
