Sakurai N, Sasaki M
Jikei University, Faculty of Medicine, School of Nursing, Tokyo, Japan.
Psychiatry Clin Neurosci. 1998 Apr;52(2):253-5. doi: 10.1111/j.1440-1819.1998.tb01060.x.
The aim of this preliminary study was to investigate sleep-wake rhythm in active, healthy elderly people residing in their usual habitat. The subjects were thirty-five male volunteers within an age range of 65-95 for 3-4 days. We measured the sleep-wake rhythm of the subjects with an Actillume which is a combined wrist activity monitor and illumination recorder. Analysis of the Actillume recording showed that 24 of the 35 subjects (69%) kept continuous activity indicating good maintenance of wakefulness with high light exposure. The mean mesor of sleep-wake rhythm, however, significantly decreased in the older subjects (aged 80-95; n=15).
