THE FRAGMENTATION OF REST/ACTIVITY CYCLES IN ALZHEIMERS-DISEASE

Clinicians caring for Alzheimer patients have observed that many have disruptions in nocturnal sleep patterns. Despite their obvious clinical importance, little research has been conducted to investigate abnormal activity patterns in these patients. In this study, diurnal rest/activity patterns were examined using an electronic monitor with a movement sensor. Eighteen patients diagnosed with Alzheimer's disease were monitored for 48 consecutive hours each. Subject variables such as age, estimated duration of illness and cognitive ratings were compared for degree of association with the movement data. Analyses indicated that an estimate of the duration of illness was superior to other variables in predicting the degree of change in activity rhythms. Specifically, the longer patients had suffered from Alzheimer's disease, the more disrupted their rest/activity patterns were. Patients who were in the late stages of Alzheimer's disease were less active and rested for longer than those in the earlier stages. In addition, circadian rhythmicity was reduced in the activity patterns of these patients, The present study confirms the findings of Hopkins and Rindlisbacher (1992) indicating that rest/activity patterns are dramatically altered as a result of Alzheimer's disease.