Non-rapid eye movement sleep with low muscle tone as a marker of rapid eye movement sleep regulation

BMC Neuroscience

Table 2 Sleep variables derived from visual scoring

Variable	Night [min]	Night [%]	Morning [min]	Morning [%]
Total sleep time	162.92 ± 1.76		165.76 ± 0.97
Sleep efficiency		90.51 ± 0.98		92.37 ± 0.53
WASO	2.39 ± 0.61		5.30 ± 0.83**
Sleep latency	11.47 ± 1.38		5.28 ± 0.58**
REMS latency	72.26 ± 5.54		58.18 ± 4.00°
Movement time	3.28 ± 0.36		2.94 ± 0.30
Stage 1	7.22 ± 0.91	4.56 ± 0.62	12.99 ± 1.80*	7.93 ± 1.10*
Stage 2	93.01 ± 4.29	57.34 ± 2.90	85.50 ± 4.97*	51.55 ± 3.00*
Stage 3	29.43 ± 2.79	17.88 ± 1.60	16.29 ± 2.41**	9.86 ± 1.45**
Stage 4	9.55 ± 2.97	5.76 ± 1.78	3.77 ± 1.57*	2.30 ± 0.95*
SWS	38.98 ± 4.37	23.64 ± 2.52	20.06 ± 3.53**	12.16 ± 2.14**
NREMS	131.99 ± 2.51	80.99 ± 1.22	105.56 ± 3.73**	63.71 ± 2.25**
REMS	23.71 ± 2.17	14.46 ± 1.28	47.21 ± 2.70**	28.36 ± 1.61**
Sleep cycle	89.7 ± 2.4		88.4 ± 4.1
NREMS episode	70.0 ± 2.1		55.62.0**
REMS episode	19.7 ± 1.5		32.7 ± 3.7*

Mean values and standard errors (SEM) are reported (n = 16, 63 night and morning recordings of 16 subjects, except for sleep cycle duration: n = 15, one subject was excluded because of a 'skipped' first REMS episodes in all 4 nights). Mean values were first calculated within subjects prior to averaging across subjects. Stages are in min and in % of total sleep time. For night sleep, only the three first hours after lights out were used for the analyses. Statistics: comparison of night and morning sleep episodes by paired t-tests, * p < 0.01, ** p < 0.001
°n = 9, only subjects with at least one morning sleep episode without SOREMS (Sleep Onset REMS episodes: REMS episodes with latency < 20 min) were included.
WASO: waking after sleep onset; SWS: stages 3 and 4, NREMS: stages 2,3 and 4; REMS latency: time from sleep onset (first occurrence of stage 2) to the first occurrence of REMS.

ISSN: 1471-2202