Venue: BBS
And on Zoom: https://u-bordeaux-fr.zoom.us/j/87806586537
Meeting ID: 878 0658 6537
Defense in french
Aurore Jouvencel
Team: SWAN
Supervisor: Gwénaëlle Catheline
Title
Sleep-wake cycle and brain vulnerabilities in the elderly: A neuroimaging and actigraphy study
Abstract
With the growing numbers of older people in our societies, we need to better understand the risk factors of morbidity and mortality. We took an interest in a modifiable risk factor of neurodegenerative diseases, the sleep-wake cycle. The main objective of this thesis was to determine how disturbances in the sleep and sleep-wake cycle can constitute factors of brain vulnerability. We used a combination of ecological measurements of the sleep-wake cycle and multimodal imaging collected from cohorts of French and Dutch volunteers in order to comprehensively understand the relationship between the sleep-wake cycle and brain health. We first showed the complementarity of objective and subjective methods (actimetry and PSQI) to assess the quality and duration of sleep. But in a cohort of French older people, living in the countryside, the subjective measure of sleep problems was peculiar and was positively correlate with cognitive abilities, contradicting the literature. Establishing a need to use objective measure of sleep in this kind of population. By studying the links between sleep quality and self-reported frequency of dizziness, we were able to observe that poor subjective sleep quality was significantly linked to the prevalence of dizziness while no link was observed with objective measures of sleep.
Then we demonstrated that day-to-day variability in the objective quality of sleep at the start of the night was linked to a greater accumulation of amyloid beta proteins in the brain of elderly subjects without cognitive disorders. These results could result from a lower clearance efficiency of the glymphatic system in subjects with variable sleep. Finally, by evaluating the evolution of actimetric parameters seven years apart, we observed that the quality of sleep of people over 70 years old remains stable while the quality of their sleep-wake cycle deteriorates. Furthermore, we observed that this degradation was linked to smaller volumes of the anterior hippocampus, a structure that is particularly vulnerable in aging. We did not observe a link between the degradation of the sleep-wake cycle and functional connectivity of this structure.
All of our results suggest that the day-to-day variability of sleep and of the sleep-wake cycle seem to be good predictors of markers of more advance brain aging, through their link with two of the prodromal markers of Alzheimer’s disease, cerebral amyloid burden and hippocampalatrophy.
Keywords: Sleep, Sleep-wake cycle, MRI, Actimetry
Publications
Sleep and dizziness in middle-aged and elderly persons: A cross-sectional population-based study
Sanne J.W. Hoepel, Aurore Jouvencel, Anne van Linge, André Goedegebure, Ellemarije Altena, Annemarie I. Luik.
Sleep Epidemiology. 2023-12-01.
10.1016/j.sleepe.2023.100066
Night-to-night variability in sleep and amyloid beta burden in normal aging
Aurore Jouvencel, Marion Baillet, Marie Meyer, Bixente Dilharreguy, Frederic Lamare, Karine Pérès, Catherine Helmer, Jean-François Dartigues, Hélène Amieva, Willy Mayo, Gwenaëlle Catheline
Alzheimer’s & Dementia – 11 September 2023
doi.org/10.1002/dad2.12460
Jury
Ysbrand VAN DER WERF
Professeur, UMC Amsterdam Rapporteur
Christina SCHMIDT
Professeure, Université de Liège Rapporteure
Mickaël LAISNEY
Maitre de Conférence, EPHE Examinateur
Jean-Arthur MICOULAUD FRANCHI
Professeur, CHU Bordeaux Examinateur
Séverine SABIA
Professeure, INSERM Examinatrice
Gwenaëlle CATHELINE
DE, EPHE Directrice de thèse