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Decreased Actigraphic Daytime Activity is Associated with Lower Memory Performance in Cognitively-Unimpaired Individuals with Autosomal Dominant Alzheimer’s Disease INTRODUCTION: Alzheimer’s disease (AD) impacts brain regions that control circadian regulation systems such as wakefulness and daytime physical activity. Recent evidence shows that AD pathology is damaging for wake-promoting neurons. Whether early changes in wakefulness and daytime activity occur during asymptomatic stages of familial AD (fAD) remains unknown. In this study, we aimed to investigate whether daytime activity differs between cognitively-unimpaired carriers of early-onset fAD and age-matched non-carrier family members. Further, we examined the associations between daytime activity and memory performance. METHODS: A total of 25 members of the large Colombian kindred with the Presenilin1 (PSEN1) E280A mutation were included in the study (9 mutation carriers and 16 non-carriers, mean age=38.2). PSEN1 mutation carriers develop dementia before the age of 50. All subjects underwent wrist actigraphy for 7-14 days to measure daytime activity (average activity per minute and per epoch), and completed the CERAD Word List Learning and the Free and Cued Selective Reminding Test (FCSRT). RESULTS: Compared to non-carriers, mutation carriers had less average daytime activity (Mann-Whitney U Test p=.04). Higher average daytime activity was associated with better memory recall in both the CERAD word list delayed recall (r=.47, p=.05) and the FCRST delayed total recall (r=.53, p=.02). No associations with age were observed. CONCLUSION: Our results suggest that cognitively-unimpaired mutation carriers have reduced daytime activity, years before onset of dementia. Reduced daytime activity in carriers is also associated with lower memory performance. Our preliminary findings add to the growing evidence that circadian dysfunction is present in early AD, and may play an important role in subsequent memory impairment. Future research with large samples is needed to further examine sleep and circadian dysfunction in asymptomatic individuals at genetic risk for AD.
10:00 – 11:30 AM ET
HMS DSM Annual Faculty Meeting
10:00 – 11:30 AM ET
Mary A. Carskadon, PhD Introductory Meeting with HMS DSM Trainees
12:00 – 1:15 PM ET
Division of Sleep Medicine Annual Prize Lecture by Mary A. Carskadon, PhD
1:15 – 1:30 PM ET
Awarding of 2020 Harvard Medical School Division of Sleep Medicine Prize to Mary A. Carskadon, PhD
3:00 – 4:30 PM ET
4:30 – 5:30 PM ET
6:00 – 7:00 PM ET
Evening Public Lecture by Mary A. Carskadon, PhD
“Changes in Sleep Biology Create a Perfect Storm Affecting Teen Health and Well-Being”