Table 2.
Frontal NREM sleep EEG power and polysomnography.
| All patients (n = 140) | Cognitively normal (n = 105) | Cognitively impaired (n = 35) | p† | |
|---|---|---|---|---|
| 0.5–1 Hz slow oscillation (%) | 49.3, 8.9 | 49.23, 8.9 | 49.5, 9.1 | 0.91 |
| 1–4 Hz SWA (%) | 37.8, 5.7 | 38.5, 5.3 | 36.2, 662 | 0.02 |
| 1–2 Hz SWA (%) | 26.5, 4.7 | 27.1, 4.5 | 24.8, 8.4 | 0.01 |
| 2–3 Hz SWA (%) | 9.6, 1.9 | 9.6, 1.7 | 9.3, 2.3 | 0.26 |
| 3–4 Hz SWA (%) | 5.2, 1.2 | 5.1, 1.0 | 5.3, 1.4 | 0.54 |
| 4–8 Hz theta (%) | 10.8, 3.6 | 10.5, 3.6 | 11.4, 3.6 | 0.20 |
| 8–13 Hz alpha (%) | 5.9, 3.0 | 5.2, 2.9 | 6.7, 3.5 | 0.49 |
| 13–20 Hz beta (%) | 2.2, 1.4 | 2.2, 0.9 | 2.4, 1.4 | 0.93 |
| Sleep period time (min) | 422.0, 50.6 | 418.4, 53.2 | 432.8, 40.5 | 0.18 |
| Total sleep time (min) | 325.0, 76.0 | 325.6, 77.2 | 323.3, 73.6 | 0.70 |
| Wake After Sleep Onset (min) | 96.9, 60.1 | 92.8, 59.1 | 109.5, 62.2 | 0.16 |
| Sleep efficiency (%) | 74.6, 15.3 | 75.3, 15.6 | 72.5, 14.6 | 0.23 |
| Sleep latency to N2 (min) | 25.1, 40.2 | 23.9, 41.0 | 28.7, 38.1 | 0.08 |
| N1 (%) | 14.6, 9.8 | 14.2, 8.5 | 15.9, 12.9 | 0.64 |
| N2 (%) | 38.6, 13.8 | 39.6, 13.2 | 35.4, 15.2 | 0.13 |
| N3 (%) | 13.2, 8.9 | 13.1, 8.9 | 13.3, 8.9 | 0.87 |
| R (%) | 11.5, 6.7 | 11.8, 6.7 | 10.6, 6.5 | 0.35 |
| Arousal index (events/hour) | 12.7, 8.5 | 12.7, 9.0 | 12.6, 7.0 | 0.56 |
| PLMS (events/hour) | 9.4, 20.8 | 8.1, 18.1 | 13.0, 27.0 | 0.41 |
| Apnea-hypopnea index (events/hour) | 5.2, 7.8 | 5.4, 8.1 | 4.3, 6.7 | 0.58 |
| REM sleep behavior disorder, n (%) | 110 (78.6) | 81 (77.1) | 29 (82.9) | 0.48 |
Means ± standard deviations are shown;
†
Comparison of PD patients with and without cognitive impairment; uncorrected p-values are displayed. Sleep stages are presented as percentages of sleep period time. Spectral power densities are presented as percentages of total power during NREM sleep and averaged across hemispheres from frontal derivations (F3, F4). PD, Parkinson disease; SWA, slow-wave activity; N1–3, non-rapid eye movement sleep stages 1–3; R, rapid eye movement sleep; PLMS, periodic limb movements during sleep.