Table 3.
Quantitative EEG studies in patients with RTT.
| Study | Sample (n: Age) | EEG Settings | EEG Characteristics |
|---|---|---|---|
| [139] | RTT (57 including 20 in active regression (AR), 29 post-regression (PR)): 2–11) TD (37: 2–11) |
128-channel Hydrocel Geodesic Sensor Net System, 5–10 min while watching movies | Spectral power (2–50 Hz) ▼ beta (13–30 Hz) at frontal and central sites (absolute and relative) ▼ beta (13–30 Hz) at temporal sites (relative) ▼ high alpha (9–13Hz) widespread (absolute and relative) ▼ low alpha (6–9 Hz) at temporal and occipital sites (relative) ▼ low alpha (6–9 Hz) at central sites (absolute and relative) ▲ delta (2–4 Hz) widespread (relative) ▼ 1/f slope (more negative, in general and in PR) for AR: ▼ theta (4–6 Hz) at frontal sites (absolute) ▼ high alpha and beta (9–30 Hz) at frontal and central (absolute and relative) ▼ high alpha (9–13 Hz) at occipital (absolute) Abnormal development of delta and theta |
| [140] | RTT, MECP2 (32) PSV, MECP2 (4) RTT, CDKL5 (4) including Resistant Epilepsy (8), Treatment Responsive Epilepsy (16), without Epilepsy (18) Mean age: 7.69 +/− 5.22 |
8-electrode EEG, minimum of 20 min recordings during resting state | =spectral power (1–50 Hz) ▼ network activity (principal component of inter-electrode coherence) in CDKL5 compared to MECP2 ▲ left-hemispheric predominance in the occipital region Resistant > Epilepsy>no Epilepsy within RTT * ▲ left-sided parieto-occipital coherence in PSV compared to classic RTT * |
| [141] | RTT (10: 2–9) TD (15: 2–9) |
Overnight (F3, C3, and O1), slow wave sleep (SWS) | Spectral power (0.5–45 Hz), ▲ delta Absence of developmental decrease of gamma (35–45 Hz) * ▼ %SWS |
| [138] | RTT (38(20 with disease onset <1 year and 18 > 1 year): 2–8) TD (60: 2–8) |
16 channels; >15.4-s epochs | Spectral power (1.5–25 Hz) ▼ alpha ▲ theta activity in RTT ▼ central and occipital alpha ▲central and frontal theta activity in the group 1 (early disease onset). |
| [137] | RTT (9:2–8, stage 3) TD (17: 2–8) |
16 channels: eyes open (n= 6) and eyes close (n= 5); >8 4-s epochs | Relative Power (1–20 Hz) ▼ alpha and beta ▲ theta band |
| [142] | RTT (1:10) TD (10:10) |
16 channels: 20 artifact-free 5-s epochs |
Spectral power (1.5–30 Hz) ▲ delta and left anterior theta ▼ posterior alpha 1 |
| [143] | RTT (9: 10–22) Compared to unspecified normative data |
n = 11: 16–20 channels; 5–10 min of recording | Spectral power (1.0–16 Hz): ▲ low frequency activity (unspecified, statistical values not provided) |