Effect of morning bright light treatment for rest–activity disruption in institutionalized patients with severe Alzheimer's disease

BACKGROUND Disturbances in rest-activity rhythm are prominent and disabling symptoms in Alzheimer's disease (AD). Nighttime sleep is severely fragmented and daytime activity is disrupted by multiple napping episodes. In most institutional environments, light levels are very low and may not be sufficient to enable the circadian clock to entrain to the 24-hour day. The purpose of this randomized, placebo-controlled, clinical trial was to test the effectiveness of morning bright light therapy in reducing rest-activity (circadian) disruption in institutionalized patients with severe AD. METHOD Subjects (n = 46, mean age 84 years) meeting the NINCDS-ADRDA (National Institute of Neurological and Communicative Disorders and Stroke--the Alzheimer's Disease and Related Disorders Association) AD diagnostic criteria were recruited from two large, skilled nursing facilities in San Francisco, California. The experimental group received one hour (09:30-10:30) of bright light exposure (> or = 2500 lux in gaze direction) Monday through Friday for 10 weeks. The control group received usual indoor light (150-200 lux). Nighttime sleep efficiency, sleep time, wake time and number of awakenings and daytime wake time were assessed using actigraphy. Circadian rhythm parameters were also determined from the actigraphic data using cosinor analysis and nonparametric techniques. Repeated measures analysis of variance (ANOVA) was used to test the primary study hypotheses. RESULTS AND CONCLUSION Although significant improvements were found in subjects with aberrant timing of their rest-activity rhythm, morning bright light exposure did not induce an overall improvement in measures of sleep or the rest-activity in all treated as compared to control subjects. The results indicate that only subjects with the most impaired rest-activity rhythm respond significantly and positively to a brief (one hour) light intervention.

[1]  D F Swaab,et al.  Bright light therapy: improved sensitivity to its effects on rest-activity rhythms in Alzheimer patients by application of nonparametric methods. , 1999, Chronobiology international.

[2]  Kristine Yaffe,et al.  Patient and caregiver characteristics and nursing home placement in patients with dementia. , 2002, JAMA.

[3]  S. Folstein,et al.  "Mini-mental state". A practical method for grading the cognitive state of patients for the clinician. , 1975, Journal of psychiatric research.

[4]  M. Folstein,et al.  Clinical diagnosis of Alzheimer's disease , 1984, Neurology.

[5]  Anna Wirz-Justice,et al.  Dawn–dusk simulation light therapy of disturbed circadian rest–activity cycles in demented elderly , 2003, Experimental Gerontology.

[6]  Scott S. Campbell,et al.  Exposure to light in healthy elderly subjects and alzheimer's patients , 1988, Physiology & Behavior.

[7]  H. Kraemer,et al.  Sleep/Wake Disruption in Alzheimer’s Disease: APOE Status and Longitudinal Course , 2004, Journal of geriatric psychiatry and neurology.

[8]  S. Ancoli-Israel,et al.  Use of wrist activity for monitoring sleep/wake in demented nursing-home patients. , 1997, Sleep.

[9]  J. Warner,et al.  Double blind randomised placebo controlled trial of low dose melatonin for sleep disorders in dementia , 2002, International journal of geriatric psychiatry.

[10]  H. Kraemer,et al.  Sleep/Wake Cycle Disturbance in Alzheimer's Disease: How Much Is Due to an Inherent Trait? , 2002, International Psychogeriatrics.

[11]  C. M. Singer,et al.  The effects of shifting sleep two hours within a fixed photoperiod , 2005, Journal of Neural Transmission / General Section JNT.

[12]  N. Kutner,et al.  Observed sleep/wakefulness and severity of dementia in an Alzheimer's disease special care unit. , 1995, The journals of gerontology. Series A, Biological sciences and medical sciences.

[13]  M. Mirmiran,et al.  Indirect bright light improves circadian rest-activity rhythm disturbances in demented patients , 1997, Biological Psychiatry.

[14]  Sonia Ancoli-Israel,et al.  Effect of Light Treatment on Sleep and Circadian Rhythms in Demented Nursing Home Patients , 2002, Journal of the American Geriatrics Society.

[15]  T Hope,et al.  Predictors of institutionalization for people with dementia living at home with a carer , 1998, International journal of geriatric psychiatry.

[16]  Philip Scheltens,et al.  Circadian rest—activity rhythm disturbances in alzheimer's disease , 1996, Biological Psychiatry.

[17]  L. Thal,et al.  A multicenter, placebo-controlled trial of melatonin for sleep disturbance in Alzheimer's disease. , 2003, Sleep.

[18]  S. Ancoli-Israel,et al.  Illumination levels in nursing home patients: effects on sleep and activity rhythms , 2000, Journal of sleep research.

[19]  A. Satlin,et al.  Bright light treatment of behavioral and sleep disturbances in patients with Alzheimer's disease. , 1992, The American journal of psychiatry.

[20]  J. Yesavage,et al.  Development of Diagnostic Criteria for Defining Sleep Disturbance in Alzheimer's Disease , 2003, Journal of geriatric psychiatry and neurology.

[21]  S. Ancoli-Israel,et al.  Sleep dysfunction in Alzheimer’s disease and other dementias , 2003, Current treatment options in neurology.