The circadian rest-activity cycle in XXXX .

@entity1 @entity303 @entity167 @entity854 @entity716 @entity195
OBJECTIVES: @entity195 ( @entity195 ) has been associated with diminished function of the biological clock in the suprachiasmatic nuclei (SCN) and pronounced circadian sleep-wake cycle disturbances. Few studies have investigated other @entity303 etiologies. Because @entity167 acts on the SCN and modifies circadian rhythms in animal studies, @entity716 ( @entity716 ) may also be associated with circadian @entity854 . This pilot study investigated the rest-activity cycle of @entity716 to see whether there were sleep-wake cycle disturbances similar to those that the authors had observed in @entity1 with @entity195 . DESIGN AND SETTING: Cross-sectional observational study in a single academic medical center. @entity1 , MEASUREMENTS: The authors investigated the circadian rest-activity cycle of six moderately demented @entity1 with @entity716 who wore an activity/lux monitor for 10-26 days and compared these patterns with those of six home-living healthy individuals of the same age group. In addition, rest-activity cycle data from previous studies of @entity1 with @entity195 were examined. INTERVENTIONS: None. RESULTS: The rest-activity cycle of @entity716 was remarkably well entrained, without the marked circadian and sleep disturbances found in @entity1 with @entity195 on the same ward. @entity716 had a >2 hour earlier bedtime and rest onset than healthy subjects and a 30-minute earlier wake-up time, resulting in longer nocturnal rest duration. The major difference was a greatly diminished daytime activity level and extremely low light exposure. CONCLUSION: A stably entrained, although low-amplitude and phase-advanced rest-activity cycle may reflect the different neuropathology of demented @entity1 with @entity716 compared with @entity1 with @entity195 .
