Pierre Champetier (ICM, Paris): "Local sleep in early Alzheimer’s disease"

Monday 15 Dec 2025, 14:00 → 15:00 Europe/Brussels

B-30/0-000 - Big meeting room (CRC)

Abstract: An increasing body of evidence has highlighted the critical role of sleep slow waves in facilitating the clearance of brain waste, affecting the accumulation of Alzheimer's disease (AD) brain lesions. Interestingly, recent studies have identified sleep-like slow waves in wake EEG of young adults, often interpreted as intrusions of local sleep during wakefulness. The occurrence of these wake slow waves (wSW) is known to increase during sleep deprivation, and can predict behavioral errors across various tasks. We explored the associations between wSW features and 1) AD brain lesions, and 2) cognitive performance in older adults with subjective cognitive decline (SCD), often considered to be at risk for developing AD. 

We analyzed data from 274 SCD individuals from the INSIGHT-preAD cohort (76.6 ± 3.5 years, range: 70-85 years). Amyloid (A) and neurodegeneration (N) status were assessed at baseline and after 2 years, using Florbetapir and 18F-FDG PET scans. wSW were detected in high-density EEG recordings (2min resting-state, 256 channels) at both time points and were divided according to their frequency in delta (1-4 Hz) and theta (4-7 Hz) waves. Cognitive performance was assessed at baseline using three composite scores (memory, attention, and executive functions) derived from standardized neuropsychological tests. Linear models were applied to each EEG channel to examine wSW features during resting-state in relation to 1) cognitive composite scores, 2) current A and N status, and 3) transitions to A+ between baseline and year-2 follow-up. 

We found that higher amplitude of wSW correlated with poorer cognition. Besides, wSW patterns are modulated by current A/N status. Finally, among individuals who were amyloid negative (A-)  at baseline, those who transitioned to amyloid positivity (A+) during the 2-year follow-up exhibited wSW with higher amplitude at baseline (i.e., while still being A-) compared to those who remained A- or to those already A+ at baseline.

Overall, this first study exploring wSW in a population of older adults suggests that these EEG metrics, measured during a simple resting-state recording, hold promise for identifying individuals at risk of progressing along the AD continuum at early stages of the disease, even before cognitive decline onset. 

Biosketch: I’m a postdoctoral fellow at the Paris Brain Institute (ICM) in France. My research focuses on sleep alterations (notably sleep spindles and slow waves) in older adults, and in the context of Alzheimer's disease. After completing my PhD in Caen at the Cyceron center under the supervision of Géraldine Rauchs, I joined the Oudiette/Arnulf team at the ICM. Here, I work with Thomas Andrillon and Delphine Oudiette on local sleep and Targeted Memory Reactivation (TMR) in older adults with and without cognitive impairments.