Methods. Sixty-nine subjects fulfilling criteria for MCI were enrolled; cortical connectivity (spectral coherence) and (low resolution brain electromagnetic tomography) sources of EEG rhythms (δ=2–4 Hz; θ=4–8 Hz; α 1=8–10.5 Hz; α 2=10.5–13 Hz: β 1=13–20 Hz; β 2=20–30 Hz; and γ=30–40) were evaluated at baseline (time of MCI diagnosis) and follow up (about 14 months later). At follow-up, 45 subjects were still MCI (MCI Stable) and 24 subjects were converted to AD (MCI Converted).
Results. At baseline, fronto-parietal midline coherence as well as δ (temporal), θ (parietal, occipital and temporal), and α 1 (central, parietal, occipital, temporal, limbic) sources were stronger in MCI Converted than stable subjects (P<0.05). Cox regression modeling showed low midline coherence and weak temporal source associated with 10%annual rate AD conversion, while this rate increased up to 40%and 60%when strong temporal δ source and high midline γ coherence were observed respectively.
Interpretation. Low-cost and diffuse computerized EEG techniques are able to statistically predict MCI to AD conversion.