Table 5. Overall descriptive effects of AD and MCI on EEG measures compared to normal aging.
| EEG Measure | Normal Aging | AD | MCI |
|---|---|---|---|
| Relative Delta Power | ↓↓ Decreasing (mainly significant after 60 years) | ↑↑ Widespread significant increase | ↑ Increased, significant only at left temporal area. |
| Relative Theta Power | ↓↓ Significant decrease at most channels | ↑ Increased power mainly significant across right hemisphere channels. | ↑ Increased, and significant only in selected channels T3,T5,T6, F3 |
| Relative Alpha Power | ~~ No significant change after 40 years old | ↓↓ Significant and widespread decrease | ~~ Not significantly different than controls. |
| Alpha Peak Frequency | ↓ Decreasing with age, only significant at limited areas (occipital and temporal) | ↓↓ Significant and widespread decrease | ~~ Not significantly different than controls (except one channel only) |
| Theta-to-Alpha Ratio (TAR) | ↓↓ Decreasing with age (widespread and significant after 60 years old) | ↑↑ Significant and widespread | ↑ Increased and significant only in temporal areas |
| PDDM(0.95,1)(Theta,Alpha) | ↓ Decreasing with age after 60 years (significant for most channels) | ↑↑ Significant and widespread increase | ↑↑ Significant increase at most channels. |
| Norm. Delta Coherence | ↑*↓ Significant increase after 40 years old followed by significant decrease after 60 years old | ↑↑ Significant and widespread increase. | ↓ Limited localized decrease in the right temporal and occipital areas |
| Norm. Theta Coherence | ↑*↓ Significant widespread increase beyond 40 years old followed by significant localized decrease beyond 60 years old | ↑↑ Significant and widespread increase | Significant decrease mainly across anterior-posterior areas with significant increase across left to right temporal areas |
| Norm. Alpha Coherence | ↓↓ Significant and widespread decrease after 40 years old and almost no change after 60 years old | ↓↓ Significant and widespread decrease | Significant decrease only in limited areas from right temporal to left-temporal and left-frontal |
↓↓ widespread significant decrease, ↑↑ widespread significant increase, ↑*↓ not a consistent trend, ~~ no significant change, (↓) limited (localized) significant decrease, (↓) limited (localized) significant increase.