Markus Canazei*, Julian Turiaux, Stefan E. Huber, Josef Marksteiner, Ilona Papousek and Elisabeth M. Weiss Pages 1084 - 1107 ( 24 )
<P>Background: Alzheimer's Disease (AD) is often accompanied by severe sleep problems and circadian rhythm disturbances which may to some extent be attributed to a dysfunction in the biological clock. The 24-h light/dark cycle is the strongest Zeitgeber for the biological clock. People with AD, however, often live in environments with inappropriate photic Zeitgebers. Timed bright light exposure may help to consolidate sleep- and circadian rest/activity rhythm problems in AD, and may be a low-risk alternative to pharmacological treatment. </P><P> Objective & Methods: In the present review, experts from several research disciplines summarized the results of twenty-seven light intervention studies which used wrist actigraphy to measure sleep and circadian activity in AD patients. </P><P> Results: Taken together, the findings remain inconclusive with regard to beneficial light effects. However, the considered studies varied substantially with respect to the utilized light intervention, study design, and usage of actigraphy. The paper provides a comprehensive critical discussion of these issues. </P><P> Conclusion: Fusing knowledge across complementary research disciplines has the potential to critically advance our understanding of the biological input of light on health and may contribute to architectural lighting designs in hospitals, as well as our homes and work environments.</P>
Light, dementia, actigraphy, sleep, circadian rhythm, physical activity.
Research Department, Bartenbach LichtLabor GmbH Ringgold Standard Institution, Bartenbach GmbH, Rinnerstrasse 14, Aldrans 6071, Department of Psychology, University of Graz, Graz, Institute of Ion Physics and Applied Physics, University of Innsbruck, Innsbruck, Tirol, Department of Psychiatry and Psychotherapy A, General Hospital, Milserstrasse 10 , Hall Tirol 6060, Department of Psychology, University of Graz, Graz, Department of Psychology, University of Graz, Graz