Sonia Ancoli-Israel, PhD, Roger Cole, PhD, Cathy Alessi, MD, Mark Chambers, PhD, William Moorcroft, PhD, Charles P. Pollak, MD; The Role of Actigraphy in the S

Approximately 50% of older adults complain of difficulty sleeping. Poor sleep results in increased risk of significant morbidity and mortality. The decrements seen in the sleep of the older adult are often due to a decrease in the ability to get needed sleep. However, the decreased ability is less a function of age and more a function of other factors that accompany aging, such as medical and psychiatric illness, increased medication use, advances in the endogenous circadian clock and a higher prevalence of specific sleep disorders. Given the large number of older adults with sleep complaints and sleep disorders, there is a need for health care professionals to have an increased awareness of these sleep disturbances to better enable them to assess and treat these patients. A thorough sleep history (preferably in the presence of their bed partner) is required for a proper diagnosis, and when appropriate, an overnight sleep recording should be done. Treatment of primary sleep problems can improve the quality of life and daytime functioning of older adults. This paper reviews the diagnoses and characteristics of sleep disorders generally found in the older adult. While aimed at the practicing geriatrician, this paper is also of importance for any gerontologist interested in sleep.

Sleep in the nursing home environment is extremely fragmented, possibly in part as a result of decreased light exposure. This study examined the effect of light on sleep and circadian activity rhythms in patients with probable or possible Alzheimer's disease. Results showed that both morning and evening bright light resulted in more consolidated sleep at night, as measured with wrist actigraphy. Evening light also increased the quality of the circadian activity rhythm, as measured by a 5-parameter extended cosine model (amplitude, acrophase, nadir, slope of the curve, and relative width of the peak and trough). Increasing light exposure throughout the day and evening is likely to have the most beneficial effect on sleep and on circadian rhythms in patients with dementia. It would behoove nursing homes to consider increasing ambient light in multipurpose rooms where patients often spend much of their days.