1019 Eeg Functional Connectivity During Wakefulness And Rem Sleep In Patients With Mild Cognitive Impairment
Bibliographic record
Abstract
Mild cognitive impairment (MCI), which is a prodrome of Alzheimer’s disease (AD), offers the opportunity to identify AD-related markers before the dementia phase. Cholinergic basal forebrain neurons, which degenerate early in AD, play a major role during Rapid-Eye-Movement (REM) sleep, at a time when several other neuronal systems are less active, leaving the cholinergic influence unmasked. Here we compared EEG functional connectivity (FC) during wakefulness and REM sleep in patients with MCI and in cognitively healthy individuals (CHI). 32 subjects with MCI (mean age 64 ± 6.1 years) and 32 subjects without cognitive impairment (mean age 63.7 ± 6.6 years) underwent a neuropsychological evaluation, a night of polysomnography and a resting-state EEG recording with 14 EEG electrodes. EEG FC was evaluated with using imaginary coherence analyses performed on manually selected artefact-free epochs in both REM sleep and resting wakefulness. Four frequency bands (delta, theta, alpha and beta) were analysed. Differences between REM sleep and wakefulness were assessed with a Welch’s t-stat. A non-parametric test on the max-stat and a permutation resampling allowed to account for multiple comparisons (between pairs of electrodes) in a false discovery rate like thresholding (p<0.04). During resting wakefulness, patients with MCI showed higher FC for the delta band, but slightly lower FC for the alpha band as compared to the CHI. During REM sleep, both groups showed a global FC decrease for the alpha band as compared to wakefulness but this decrease was less prominent in the MCI patients. Compared to CHI, patients with MCI individuals show a reduced ability to decrease FC in alpha during REM sleep with respect to wakefulness. Our results support previous reports showing higher EEG FC during wakefulness in the delta frequency and lower alpha EEG coherence in MCI patients as compared to CHI. As the cholinergic projection from the basal forebrain to the cerebral cortex is an important substratum of alpha rhythms, differences observed within this band during REM sleep could reflect the beginning of neurodegenerative changes. CIHR PJT-153259.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".