ays that this research, "can go a long way toward maintaining home care of Alzheimer's patients." O'Malley is director of the Sleep Disorders Center at Norwalk Hospital in Connecticut. In healthy people, changes in body temperature occur throughout the day and night, they are controlled by the body clock in the brain, and they mimic activity cycles. In general, body temperature is lowest when activity levels are lowest, such as in the middle of the night, and body temperature is at its highest during periods of highest activity, such as in the middle of the day. Harper and his colleagues studied the daily activity and body temperature cycles of 38 men who had Alzheimer's disease or another type of dementia, called frontotemporal degeneration, or FTD. Patients with Alzheimer's disease were not only more active at night, but they also had a higher body temperature during this time period. In contrast, the daily body temperature rhythms of patients with FTD were similar to those of healthy individuals even though they were also more wakeful at night. "Even though sleep disturbance is a common symptom of these two dementias, the cause of it appears to be entirely different," says Harper. These results suggest that efforts to 'reset' the brain body clock -- the part of the brain that determines sleep/wake cycles, through such strategies as giving patients the sleep hormone melatonin or exposing them to bright light at certain times of the day, should work in Alzheimer's patients but not FTD patients. Melatonin is a hormone that's produced especially at night in a gland in the brain. It is released in response to darkness and inhibited by light. It has been touted as effective treatment for jet lag and to improve longevity, among other things, though none of the claims have been conclusively proven. Traditionally, these therapies have not always worked for Alzheimer's patients, but Harper says this is because experts did not realize how sever...
