Pollak C P, Stokes P E
Department of Neurology, Ohio State University, Columbus 43210, USA.
J Am Geriatr Soc. 1997 Apr;45(4):446-52. doi: 10.1111/j.1532-5415.1997.tb05169.x.
Disruptive nocturnal behaviors (DNBs) of older people often threaten the caregiving arrangements on which their community tenure depends. Dementing disorders are especially prone to result in disrupted sleep and agitated behaviors ("sundowning"). The objective here was to develop an objective correlate of DNBs, by which their severity and effects on caregivers can be measured.
Quantitative comparison of subjective sleep and motor activity patterns in older people and their caregivers. It was hypothesized that older people with reported DNBs would be more motorically active at night than their caregivers.
Subjects' homes.
Twenty-five demented and 18 nondemented older day-care participants and their paired caregivers.
Older subjects and caregivers simultaneously kept daily sleep logs and recorded wrist motor activity every .5 minute for 9 days. A novel method was devised to identify and exclude from analysis periods when the activity monitor was not being worn. Such periods were common. Activity data were analyzed by computing hourly means and by fitting cosine models by least squares.
Demented older people were not significantly more active at night than their caregivers, though group differences varied by time of night. They were significantly less active in the daytime than were their caregivers. Nondemented older people were significantly more active at night than their caregivers and were as active by day as their caregivers. The caregivers of demented and nondemented older people had similar rest-activity patterns. The mean amplitudes of cosine models were smaller in the older adults. Acrophases (peaks) fell between 2 and 3 pm and did not differ significantly among the groups.
As a result of increased nighttime motor activity and decreased daytime activity, rest-activity rhythms were flatter in older adults than in caregivers. This was not explained fully by age and does not necessarily imply that the output of a circadian pacemaker was low. Decreased daytime activity may have resulted from deficient physical stimulation or frailty. Frailty may also explain why nighttime activity was not more elevated in the demented older people. Increased nighttime activity is probably explained by depression, sleep-schedule disturbances, restless legs, or other sleep disorders. Judging by their shared variations of activity, caregivers interacted mainly with the demented older people at bedtime and at rising time in the morning.
老年人的夜间干扰行为（DNB）常常威胁到他们在社区居住所依赖的照料安排。痴呆症尤其容易导致睡眠中断和激越行为（“日落综合征”）。此处的目的是开发一种DNB的客观关联指标，借此可以衡量其严重程度及其对照料者的影响。
对老年人及其照料者的主观睡眠和运动活动模式进行定量比较。研究假设是，报告有DNB的老年人在夜间的运动活跃度会高于其照料者。
受试者家中。
25名患有痴呆症的老年人、18名未患痴呆症的老年日托参与者以及他们各自配对的照料者。
老年受试者和照料者同时记录每日睡眠日志，并连续9天每0.5分钟记录一次手腕运动活动。设计了一种新方法，用于识别并在分析中排除未佩戴活动监测器的时间段。这种情况很常见。通过计算每小时的平均值并采用最小二乘法拟合余弦模型来分析活动数据。
患有痴呆症的老年人在夜间的活跃度并不显著高于其照料者，不过组间差异因夜间时段而异。他们在白天的活跃度显著低于其照料者。未患痴呆症的老年人在夜间的活跃度显著高于其照料者，且白天的活跃度与照料者相当。患有痴呆症和未患痴呆症老年人的照料者具有相似的休息 - 活动模式。老年人中余弦模型的平均振幅较小。相位峰值（高峰）出现在下午2点至3点之间，各组之间无显著差异。
由于夜间运动活动增加和白天活动减少，老年人的休息 - 活动节律比照料者更平缓。这不能完全用年龄来解释，也不一定意味着昼夜节律起搏器的输出较低。白天活动减少可能是由于身体刺激不足或身体虚弱所致。身体虚弱也可能解释了为什么患有痴呆症的老年人夜间活动没有更高。夜间活动增加可能是由抑郁、睡眠时间表紊乱、不宁腿或其他睡眠障碍导致的。从他们活动的共同变化来看，照料者主要在就寝时间和早晨起床时与患有痴呆症的老年人互动。
