Biomarkers

Area of Science:

• Neuroscience
• Biomarkers
• Alzheimer's Disease Research

Background:

• Sleep slow waves are crucial for clearing brain waste and preventing Alzheimer's disease (AD) lesions.
• Wake slow waves (wSW), observed in wake EEG, increase with sleep deprivation and predict errors.
• This study investigated wSW features in relation to amyloid and neurodegeneration status and transitions.

Purpose of the Study:

• To compare wake slow wave (wSW) features in elderly individuals based on amyloid (A) and neurodegeneration (N) status.
• To examine wSW features in individuals transitioning to amyloid or neurodegeneration positivity.
• To explore the potential of wSW as early biomarkers for AD pathology.

Main Methods:

• Utilized EEG recordings from 314 elderly participants with memory complaints.
• Assessed amyloid and neurodegeneration status using PET scans at baseline and 2-year follow-up.
• Analyzed wSW density and amplitude in delta and theta bands, adjusting for covariates and correcting for multiple comparisons.

Main Results:

• Lower delta wSW density was observed in participants with amyloid or neurodegeneration compared to controls.
• Individuals with both amyloid and neurodegeneration showed higher wSW amplitude in delta and theta bands.
• Transitions to amyloid or neurodegeneration positivity were associated with altered wSW features (higher amplitude or lower density).

Conclusions:

• Wake slow wave (wSW) features show potential as early EEG biomarkers for amyloid deposition and neurodegeneration.
• wSW metrics are measurable via brief resting-state EEG, aiding early identification of at-risk individuals.
• These findings suggest wSW can detect preclinical AD changes before cognitive decline.