Tamar Shochat

Increased Light Exposure Consolidates Sleep and Strengthens Circadian Rhythms in Severe Alzheimer's Disease Patients

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 Alzheimers 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.

Functional consequences of inadequate sleep in adolescents: A systematic review

During adolescence, changes in sleep patterns due to biological and environmental factors are well documented. Later bedtimes and inadequate sleep, i.e., short and disrupted sleep patterns, insomnia and daytime sleepiness, have become increasingly common. Accumulating evidence suggests that sleep plays a crucial role in healthy adolescent development. This review systematically explores descriptive evidence, based on prospective and cross sectional investigations, indicating that inadequate sleep is associated with negative outcomes in several areas of health and functioning, including somatic and psychosocial health, school performance and risk taking behavior. Findings highlight the need for longitudinal investigations aimed at establishing the underpinnings of these associations and for developing and implementing interventions designed to achieve healthier and more balanced sleep patterns in the adolescent population.

Illumination levels in nursing home patients: effects on sleep and activity rhythms

Studies examining levels of illumination in adult populations have demonstrated that the level and amount of light exposure are lower in the elderly compared with younger adults, particularly in institutionalized patients with dementia. Although insufficient light exposure has been implied as a cause of sleep fragmentation, evidence for such a relationship is scant. Sixty‐six institutionalized elderly had their activity and light exposure monitored for a 3‐day period. Mean and median light levels, minutes spent over 1000 and over 2000 lux, percent sleep and wake, and number of naps were computed for daytime intervals, defined as 07.00–18.59. Percentages of sleep and wake, number of awakenings and mean duration of wake periods were computed for night‐time intervals, defined as 22.00–05.59. Mesor, amplitude and acrophase of activity and of light were determined by cosinor analysis. A mixed linear model was used to assess the effects of daytime Actillume measures on subsequent night‐time measures, and vice versa. Spearman correlations were computed, and multiple regression analyses were carried out with light variables and dementia level as predictors and sleep–wake and activity measures as dependent variables. The median light level was 54 lux and a median of only 10.5 min were spent over 1000 lux. Higher light levels predicted fewer night‐time awakenings, and severe dementia predicted more daytime sleep and lower mean activity. Increased bright light exposure predicted later activity acrophase. There was an association between the acrophases of light and of activity, with maximum illumination preceding peak activity. These results suggest that daytime light exposure has an impact on both night‐time sleep consolidation and timing of peak activity level.

Changes in Cognitive Function Associated with Sleep Disordered Breathing in Older People

OBJECTIVES: Sleep disordered breathing (SDB) is very common in older people and is known to be associated with complaints of impaired daily functioning, including excessive daytime sleepiness and cognitive impairments. As part of a larger study on SDB and aging, it became possible to examine the relationship between SDB and cognition in older men and women.

Melatonin fails to improve sleep or agitation in double-blind randomized placebo-controlled trial of institutionalized patients with Alzheimer disease.

OBJECTIVES Patients with Alzheimer dementia often display both agitated behavior and poor sleep. Given that the disease is often associated with low endogenous levels of melatonin, exogenous melatonin administration may lead to improvements in sleep and agitation. DESIGN Randomized, placebo-controlled study. SETTING Nursing homes in San Diego, CA, metropolitan area. PARTICIPANTS Subjects were patients with probable Alzheimer disease. INTERVENTION Melatonin (8.5 mg immediate release and 1.5 mg sustained release) (N = 24) or placebo (N = 17) administered at 10:00 P.M. for 10 consecutive nights. The protocol consisted of baseline (3 days), treatment (10 days), and posttreatment (5 days) phases. MEASUREMENTS Sleep was measured continuously using actigraphy. Agitation was rated using both the Agitated Behavior Rating Scale and the Cohen-Mansfield Agitation Inventory. Treatment effects were examined both across the 24-hr day and separately by nursing shift. RESULTS There were no significant effects of melatonin, compared with placebo, on sleep, circadian rhythms, or agitation. CONCLUSION : This study failed to find a beneficial effect of exogenous melatonin, consistent with a number of other studies. The lack of efficacy may be related to the absence of a true treatment effect or to the superphysiologic dose of melatonin used.

CIRCADIAN RHYTHMS OF AGITATION IN INSTITUTIONALIZED PATIENTS WITH ALZHEIMER'S DISEASE

Agitation is a common problem in institutionalized patientswith Alzheimers disease (AD). “Sundowning,” or agitationthat occurs primarily in the evening, is estimated to occur in 10—25%of nursing home patients. The current study examined circadian patterns ofagitation in 85 patients with AD living in nursing homes in the San Diego,California, area. Agitation was assessed using behavioral ratings collectedevery 15 minutes over 3 days, and activity and light exposure data were collectedcontinuously using Actillume recorders. A five-parameter extension of thetraditional cosine function was used to describe the circadian rhythms. Themean acrophase for agitation was 14:38, although there was considerable variabilityin the agitation rhythms displayed by the patients. Agitation rhythms weremore robust than activity rhythms. Surprisingly, only 2 patients (2.4%) were“sundowners.”In general, patients were exposed to very low levelsof illumination, with higher illumination during the night being associatedwith less robust agitation rhythms with higher rhythm minima (i.e., some agitationpresent throughout the day and night). Seasonality was examined; however,there were no consistent seasonal patterns found. This is the largest studyto date to examine agitation rhythms using behavioral observations over multiple24h periods. The results suggest that, although sundowning is uncommon, agitationappears to have a strong circadian component in most patients that is relatedto light exposure, sleep, and medication use. Further research into the understandingof agitation rhythms is needed to examine the potential effects of interventionstargeting sleep and circadian rhythms. (ChronobiologyInternational, 17(3), 405–418, 2000)

Sleep-disordered breathing and agitation in institutionalized adults with Alzheimer disease.

OBJECTIVE The authors examined the relationship between sleep-disordered breathing (SDB) and agitation in patients with Alzheimer disease (AD). METHODS Thirty-eight AD patients (29 women, 9 men) in nursing homes in San Diego, CA participated. The mean age was 82.3 years, with a range of 61 to 95 years. Mean Mini-Mental State Exam score was 6.5 (range: 0-16). Sleep was recorded for one night, and agitation was measured with behavioral observations and ratings by nursing staff. RESULTS SDB was very prevalent in this sample and was related to some types of agitation during the day but not in the evening or night. Aggressive Agitation on the Cohen-Mansfield Agitation Inventory and Manual Manipulation on the Agitated Behavior Rating Scale were greater with more severe SDB. Searching and wandering agitation decreased with more severe SDB. CONCLUSION This study supports the hypothesis that SDB is related to agitation in AD, although the results are specific to certain types of agitation. Treatment of SDB may decrease agitation, easing the burden of caregiving and prolonging the time that patients are able to remain at home.

Eveningness, Sleep Patterns, Daytime Functioning, and Quality of Life in Israeli Adolescents

The purpose of the study was to assess the relationships between eveningness, sleep patterns, measures of daytime functioning, i.e., sleepiness, sleep problem behaviors, and depressed mood, and quality of life (QOL) in young Israeli adolescents. A cross-sectional survey was performed in urban and rural middle schools in Northern Israel. Participants were 470 eighth and ninth grade middle school students (14 ± 0.8 yrs of age) in the normative school system. Students completed the modified School Sleep Habits Survey (SSHS) and Pediatric Quality of Life Inventory Short Form, assessing six subscales of physical, emotional, social, school performance, and psychosocial functioning, plus an addition generated total score. During weekdays and weekends, evening types went to bed later, their sleep latency was longer, their wake-up time was later, and their sleep duration was shorter than intermediate and morning types. Evening types exhibited more sleep problem behaviors, sleepiness, depressed mood, and lower QOL compared to intermediate and morning types. Based on the regression model, sleepiness, sleep-problem behaviors, and depressed mood were the variables most strongly associated with QOL, followed by morning-evening preference, weekday sleep duration, and weekend sleep latency. This study is the first to assess QOL in normative, healthy adolescents and to demonstrate strong associations between morning-evening preference and QOL. These findings enhance the need to identify young individuals with an evening preference, and to be aware of the characteristics and manifestations of the evening chronotype on daytime and nighttime behaviors in adolescence. (Author correspondence: Orna@yvc.ac.il)

Sleep patterns, electronic media exposure and daytime sleep-related behaviours among Israeli adolescents.

Aim:  The aim of this study was to assess weekday and weekend sleep patterns and their relationships with electronic media (television and computer) exposure and with daytime sleep‐related behaviours, including sleep problem behaviours, sleepiness and fatigue in Israeli adolescents.

Melatonin - the key to the gate of sleep

This article reviews the evidence that melatonin, a hormone produced by the pineal gland during the dark hours, plays a major role in the regulation of the sleep-wake cycle. In recent years, our laboratory has been involved in a large-scale project aimed at investigating the role of endogenous melatonin in sleep-wake regulation and the effects of nonpharmacological levels of melatonin on sleep. Based on our finding on the precise coupling between the endogenous nocturnal increase in melatonin secretion and the opening of the nocturnal sleep gate, we propose that the role of melatonin in the induction of sleep does not involve the active induction of sleep, but is rather mediated by an inhibition of a wakefulness-producing mechanism in the central nervous system. Our studies also suggest that exogenously administered melatonin may be beneficial in certain types of insomnia that are related to disturbances in the normal secretion of the hormone.