By Karla Gale
NEW YORK (Reuters Health) – Problems with sleep fragmentation and circadian rhythm abnormalities are improved when patients with dementia are exposed to bright light in the morning, investigators in San Diego report. Using a technique such as this may help prevent patients from wandering in the middle of night or sleeping all day, perhaps even postponing institutionalization.
Dr. Sonia Ancoli-Israel, of the University of California in San Diego, and colleagues randomly assigned 77 nursing home residents to morning bright light therapy, evening bright light, daytime sleep restriction, or evening dim red light. The patients ranged in age from 60 to 100, and had scores on the Mini-Mental State examination that averaged 12.8.
For the bright light groups, patients were placed in front of light boxes at 2500 lux for 2-hour periods begun at 9:30 a.m. or 5:30 p.m. For the 18-day trial periods, patients wore small wrist devices that recorded the average of all activity movements per minute and the maximum movement per minute.
Morning light exposure resulted in delayed activity rhythms of all patients in that group. The increase averaged nearly 2 hours. "When the activity rhythm is delayed, patients would stay alert a little bit later in the day and sleep later in morning," Dr. Ancoli-Israel told Reuters Health. Mean activity levels also increased significantly from baseline.
According to Dr. Ancoli-Israel, the patients exposed to morning bright light exhibited more sustained sleep and wake patterns. In contrast, "what we usually see in nursing homes is sleep that is so disrupted that patients often are never awake for a full hour or asleep for a full hour throughout the 24-hour day," she said.
"I would encourage any caregiver, whether in a private home or a nursing home, to try to increase patients' morning light exposure," she continued. "The best thing is to get them outside into the sunlight, or to sit them near a window when the sun is pouring in."
She advises that if nursing home personnel want to institute artificial light therapy, they should build in bright lights in the ceiling of rooms where patients spend a lot of time, such as multipurpose rooms or lounges. She also recommends that those interested should check out the web page of the Society for Light Therapy and Biological Rhythms (www.sltbr.org).
"There is a link to manufacturers who make light boxes and who can advise people how to integrate bright light into conventional room lights," she added.