Human Sleep EEG Analysis Using the Correlation Dimension

2001 ◽  
Vol 32 (3) ◽  
pp. 112-118 ◽  
Author(s):  
Toshio Kobayashi ◽  
Shigeki Madokoro ◽  
Yuji Wada ◽  
Kiwamu Misaki ◽  
Hiroki Nakagawa
Keyword(s):  
Rem Sleep ◽  
Correlation Dimension ◽  
Degrees Of Freedom ◽  
Slow Wave Sleep ◽  
Sleep Stage ◽  
Sleep Eeg ◽  
Sleep Cycle ◽  
Sleep Stages ◽  
The Mean ◽  
Male Subjects

Sleep electroencephalograms (EEG) were analyzed by non-linear analysis. Polysomnography (PSG) of nine healthy male subjects was analyzed and the correlation dimension (D2) was calculated. The D2 characterizes the dynamics of the sleep EEG, estimates the degrees of freedom, and describes the complexity of the signal. The mean D2 decreased from the awake stage to stages 1,2,3 and 4 and increased during rapid eye movement (REM) sleep. The D2 during each REM sleep stage were high and those during each slow wave sleep stage were low, respectively, for each sleep cycle. The mean D2 of the sleep EEG in the second half of the night was significantly higher than those in the first half of the night. Significant changes were also observed during sleep stage 2, but were not seen during REM sleep and sleep stages 3 and 4. The D2 may be a useful method in the analysis of the entire sleep EEG.

nCPAP Treatment of Obstructive Sleep Apnea Increases Slow Wave Sleep in Prefrontal EEG

2007 ◽  
Vol 38 (3) ◽  
pp. 148-154 ◽  
Author(s):  
Veera Eskelinen ◽  
Toomas Uibu ◽  
Sari-Leena Himanen
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Treatment Period ◽  
Slow Wave ◽  
Slow Wave Sleep ◽  
Sleep Stage ◽  
Sleep Eeg ◽  
Sleep Stages ◽  
Obstructive Sleep ◽  
Sleep Stage Scoring

According to standard sleep stage scoring, sleep EEG is studied from the central area of parietal lobes. However, slow wave sleep (SWS) has been found to be more powerful in frontal areas in healthy subjects. Obstructive sleep apnea syndrome (OSAS) patients often suffer from functional disturbances in prefrontal lobes. We studied the effects of nasal Continuous Positive Airway Pressure (nCPAP) treatment on sleep EEG, and especially on SWS, in left prefrontal and central locations in 12 mild to moderate OSAS patients. Sleep EEG was recorded by polysomnography before treatment and after a 3 month nCPAP treatment period. Recordings were classified into sleep stages. No difference was found in SWS by central sleep stage scoring after the nCPAP treatment period, but in the prefrontal lobe all night S3 sleep stage increased during treatment. Furthermore, prefrontal SWS increased in the second and decreased in the fourth NREM period. There was more SWS in prefrontal areas both before and after nCPAP treatment, and SWS increased significantly more in prefrontal than central areas during treatment. Regarding only central sleep stage scoring, nCPAP treatment did not increase SWS significantly. Frontopolar recording of sleep EEG is useful in addition to central recordings in order to better evaluate the results of nCPAP treatment.

Scalp Topographic Distribution of Beta and Gamma Ratios During Sleep

2002 ◽  
Vol 16 (2) ◽  
pp. 107-113 ◽  
Author(s):  
Raffaele Ferri ◽  
Paolo Bergonzi ◽  
Filomena I.I. Cosentino ◽  
Maurizio Elia ◽  
Bartolo Lanuzza ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Sleep Stage ◽  
Power Spectra ◽  
Sleep Stages ◽  
Central Field ◽  
Subcortical Structures ◽  
Additional Time ◽  
The Difference ◽  
Topographic Distribution

Abstract The present study analyzes the topographic distribution of two newly introduced measures related to the beta and gamma EEG bands during REM sleep. For this purpose, power spectra of three EEG channels (F4, C4, and O2, all referred to A1) were obtained by means of the fast Fourier transform, and the power of the bands ranging from 0.75-4.50 Hz (delta) and 12.50-15.00 (sigma) was calculated for the whole period of analysis (7 h) in 10 healthy subjects. Also, two additional time series - the ratio between beta and gamma2 and between gamma1 and gamma2 - were calculated (beta and gamma ratios). The difference between the mean group values of the delta and sigma bands power, and of the beta and gamma ratios, during the different sleep stages, over the three different scalp locations recorded was evaluated by means of the nonparametric Friedman ANOVA. During non-REM slow-wave sleep, the delta band showed the highest values over the central and frontal regions, followed by those observed over the occipital lead. During sleep stage 2, the sigma band showed the highest values over the central regions, followed by those observed over the occipital areas and, lastly, those from the frontal lead. During REM sleep, the beta ratio showed its highest values over the central field, which were significantly higher that those obtained from both the frontal and the occipital regions. The gamma ratio showed a statistically nonsignificant tendency to show a similar topographic distribution pattern. Sleep can be considered a complex phenomenon with a differential involvement of multiple cortical and subcortical structures. The analysis of high-frequency EEG bands and of our beta and gamma ratios represent an additional important element to include in the study of sleep.

Sweating responses and body temperatures during nocturnal sleep in humans

1987 ◽  
Vol 252 (3) ◽  
pp. R462-R470 ◽  
Author(s):  
J. C. Sagot ◽  
C. Amoros ◽  
V. Candas ◽  
J. P. Libert
Keyword(s):  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Thermal Environment ◽  
Sweat Rate ◽  
Sleep Stage ◽  
Dew Point ◽  
Sleep Stages ◽  
Body Temperatures ◽  
Time Patterns ◽  
Stage 1

The changes in the central control of sweating were investigated in five sleeping subjects under neutral and warm conditions [operative temperature (To) = 30, 33, and 34 degrees C; dew-point temperature = 10 degrees C]. Esophageal (Tes) and mean skin (Tsk) temperatures, chest sweat rate (msw,1), and concomitant electroencephalographic data were recorded. Throughout the night, msw,1 was measured under a local thermal clamp of 38 degrees C. Results showed that the thermal environment exerted a strong influence on both the levels and the time patterns of body temperatures. Moreover, local sweating rate correlated positively with Tes, and this relationship varied according to sleep stages. For a given Tes level, there was a sleep stage-related gradation in msw,1 that was higher in slow-wave sleep (SWS) than in stage 1-2 and the lowest in rapid-eye-movement (REM) sleep. This is explained by a change in the excitability or the sensitivity of the thermoregulatory system. The msw,1 differences between stage 1-2 and SWS are accounted for by a decrease in the Tes threshold (Tset) for sweating while the slope of the msw,1-Tes relation remains unchanged. The lower msw,1 in REM sleep is explained by a lesser slope for the msw,1-Tes relation without any Tset change from stage 1-2.

Relationship between enteric migrating motor complex and the sleep cycle

1990 ◽  
Vol 259 (6) ◽  
pp. G983-G990 ◽  
Author(s):  
D. Kumar ◽  
C. Idzikowski ◽  
D. L. Wingate ◽  
E. E. Soffer ◽  
P. Thompson ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Sleep Stage ◽  
Total Duration ◽  
Migrating Motor Complex ◽  
Sleep Cycle ◽  
Sleep Stages ◽  
Nocturnal Sleep ◽  
Motor Complex ◽  
Fluoroscopic Control ◽  
Ligament Of Treitz

To address the question of synchrony between two major biorhythms with a similar periodicity, the cortical rapid eye movement (REM)/non-REM sleep cycle and the enteric migrating motor complex (MMC cycle), we recorded upper small bowel motor activity and sleep activity during nocturnal and diurnal sleep in six healthy subjects. Motility was measured continuously using a fine (2.2 mm OD) and relatively comfortable nasojejunal probe with two pressure-sensitive microtransducers positioned under fluoroscopic control on either side of the ligament of Treitz. Sleep stages were recorded while the subjects slept in a sleep laboratory. Each subject was studied twice; once during normal nocturnal sleep and then after acute reversal of sleep by advancing the time of going to bed by 4 h each night for three nights. The total duration of sleep was similar for diurnal and nocturnal sleep. There was a significantly higher number of REM episodes (P less than 0.001) and REM sleep stage shifts (P less than 0.02) during diurnal (reversed) sleep. During sleep (both diurnal and nocturnal) there was a significant reduction in the MMC cycle length (P less than 0.02, P less than 0.03) and the duration of phase II of the MMC (P less than 0.009, P less than 0.02). The distribution of MMCs among sleep stages and REM sleep was consistent with a random distribution. These data show that periodic activity in the gut is modulated by the presence or absence of sleep, but they also are consistent with the hypothesis that the two cycles are independent and that one is not contingent upon the other.

scholarly journals Heart Rate and Heart Rate Variability Change with Sleep Stage in Dairy Cows

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2095
Author(s):  
Laura B. Hunter ◽  
Marie J. Haskell ◽  
Fritha M. Langford ◽  
Cheryl O’Connor ◽  
James R. Webster ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Dairy Cows ◽  
Rem Sleep ◽  
Sleep Stage ◽  
Sleep Stages ◽  
Promising Alternative ◽  
Gold Standard Method ◽  
The Mean ◽  
Large Animals

Changes to the amount and patterns of sleep stages could be a useful tool to assess the effects of stress or changes to the environment in animal welfare research. However, the gold standard method, polysomnography PSG, is difficult to use with large animals such as dairy cows. Heart rate (HR) and heart rate variability (HRV) can be used to predict sleep stages in humans and could be useful as an easier method to identify sleep stages in cows. We compared the mean HR and HRV and lying posture of dairy cows at pasture and when housed, with sleep stages identified through PSG. HR and HRV were higher when cows were moving their heads or when lying flat on their side. Overall, mean HR decreased with depth of sleep. There was more variability in time between successive heart beats during REM sleep, and more variability in time between heart beats when cows were awake and in REM sleep. These shifts in HR measures between sleep stages followed similar patterns despite differences in mean HR between the groups. Our results show that HR and HRV measures could be a promising alternative method to PSG for assessing sleep in dairy cows.

scholarly journals Brainstem cholinergic modulation of the thalamocortical activity in urethane anesthetized mice.

2021 ◽  
Author(s):  
Y Audrey Hay
Keyword(s):  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Sleep Stage ◽  
Cholinergic Neurons ◽  
Sleep Stages ◽  
Thalamic Nuclei ◽  
Compensatory Mechanisms ◽  
Thalamic Neurons ◽  
Up States ◽  
Low Tone

In mammals, sleep consists in the recurrence of two main stages the rapid eye movement (REM) sleep and the slow wave sleep (SWS). The full expression of sleep rhythms requires an intact thalamocortical loop, and its modulation by neuromodulators such as acetylcholine. A high tone of acetylcholine is observed during REM sleep while a low tone of acetylcholine modulates the cortical slow waves during SWS. Brainstem Cholinergic neurons activity correlates with cortical sleep stages but these neurons do not project directly to the cortex. Instead, they could contribute to cortically-recorded sleep stage modulation via a thalamic relay, in particular via the midline thalamic nuclei. Focusing on the brainstem LDTg cholinergic neurons, I investigated how midline thalamic single unit activity and cortical sleep-like stages are modulated during optogenetic-induced activation or silencing of LDTg cholinergic neurons in urethane anesthetized mice. Thalamic neurons were more active during REM-like than SWS-like stages. Bursting activity predominated during SWS-like while tonic firing was prominent during REM-like stage. Optogenetic silencing of the brainstem LDTg cholinergic neurons abolished REM-like stages and reduced tonic spiking of thalamic neurons. Moreover, during SWS-like, silent Down states were prolonged and thalamic tonic spiking during Up states was reduced. Stimulation of the brainstem LDTg cholinergic neurons had a mild effect on thalamic activity even though tonic discharge was increased. Surprisingly, optogenetic stimulation abolished as well REM-like stages maybe through compensatory mechanisms.

scholarly journals Sleep, Subcortical Stimulation and Kindling in the Cat

1975 ◽  
Vol 2 (4) ◽  
pp. 447-455 ◽  
Author(s):  
T. Tanaka ◽  
H. Lange ◽  
R. Naquet
Keyword(s):  
Rem Sleep ◽  
Sleep Stage ◽  
Low Frequency ◽  
Mesencephalic Reticular Formation ◽  
Seizure Threshold ◽  
Sleep Stages ◽  
Central Gray Matter ◽  
Spike Discharge ◽  
Amygdaloid Stimulation ◽  
Stimulation Of

SUMMARY:A longitudinal study of the effects of sleep on amygdaloid kindling showed that kindling disrupted normal sleep patterns by reducing REM sleep and increasing awake time. Few interictal spike discharges were observed during the awake stage, while a marked increase in discharge was observed during the light and deep sleep stages. No discharges were observed during REM sleep. During the immediate post-stimulation period the nonstimulated amygdala showed a much higher rate of spike discharge. On the other hand, there was an increase in spike discharge in the stimulated amygdala during natural sleep without preceding amygdaloid stimulation. Amygdaloid stimulation at the generalized seizure threshold during each sleep stage resulted in a generalized convulsion.The influence of subcortical electrical stimulation on kindled amygdaloid convulsions was investigated in a second experiment. Stimulation of the centre median and the caudate nucleus was without effect on kindled convulsions, while stimulation of the mesencephalic reticular formation at high frequency (300 Hz) reduced the latency of onset of kindled generalized convulsions. Stimulation of the nucleus ventralis lateralis of the thalamus at low frequency (10 Hz) prolonged the convulsion latency, and at high current levels blocked the induced convulsion. Stimulation in the central gray matter at low frequency (10 Hz) also blocked kindled amygdaloid convulsions.

Correlations using the NREM-REM sleep cycle frequency support distinct regulation mechanisms for REM and NREM sleep

2002 ◽  
Vol 93 (1) ◽  
pp. 141-146 ◽  
Author(s):  
O. Le Bon ◽  
L. Staner ◽  
S. K. Rivelli ◽  
G. Hoffmann ◽  
I. Pelc ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Healthy Subjects ◽  
Nrem Sleep ◽  
Sleep Cycle ◽  
Cycle Frequency ◽  
Regulation Mechanisms ◽  
The Mean ◽  
Number Of Cycles ◽  
The Relationship ◽  
Sleep Cycles

Polysomnograms of most homeothermic species distinguish two states, rapid eye movement (REM) and non-REM (NREM) sleep. These alternate several times during the night for reasons and following rules that remain poorly understood. It is unknown whether each state has its own function and regulation or whether they represent two facets of the same process. The present study compared the mean REM/NREM sleep ratio and the mean number of NREM-REM sleep cycles across 3 consecutive nights. The rationale was that, if REM and NREM sleep are tightly associated, their ratio should be comparable whatever the cycle frequency in the night. Twenty-six healthy subjects of both sexes were recorded at their home for 4 consecutive nights. The correlation between the REM/NREM sleep ratio and the number of cycles was highly significant. Of the two sleep components, REM sleep was associated to the number of cycles, whereas NREM sleep was not. This suggests that the relationship between REM sleep and NREM sleep is rather weak within cycles, does not support the concept of NREM-REM sleep cycles as miniature units of the sleep process, and favors the concept of distinct mechanisms of regulation for the two components.

scholarly journals 1193 Accuracy of a Commercial Wearable in Detecting Sleep Stages Compared to Polysomnography in Adults: Considering Sleep Classification Methods and Effects of Evening Alcohol Consumption

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A456-A457 ◽  
Author(s):  
L Menghini ◽  
V Alschuler ◽  
S Claudatos ◽  
A Goldstone ◽  
F Baker ◽  
...  
Keyword(s):  
Alcohol Consumption ◽  
Rem Sleep ◽  
Sleep Stage ◽  
Cardiac Activity ◽  
Sleep Stages ◽  
Classification Methods ◽  
Management Platform ◽  
Wake Patterns ◽  
Wake Detection ◽  
Data Management Platform

Abstract Introduction Commercial wearable devices have shown the capability of collecting and processing multisensor information (motion, cardiac activity), claiming to be able to measure sleep-wake patterns and differentiate sleep stages. While using these devices, users should be aware of their accuracy, sources of measurement error and contextual factors that may affect their performance. Here, we evaluated the agreement between Fitbit Charge 2™ and PSG in adults, considering effects of two different sleep classification methods and pre-sleep alcohol consumption. Methods Laboratory-based synchronized recordings of device and PSG data were obtained from 14 healthy adults (42.6±9.7y; 6 women), who slept between one and three nights in the lab, for a total of 27 nights of data. On 10 of these nights, participants consumed alcohol (up to 4 standard drinks) in the 2 hours before bedtime. Device performance relative to PSG was evaluated using epoch-by-epoch and Bland-Altman analyses, with device data obtained from a data-management platform, Fitabase, via two methods one that accounts for short wakes (SW, awakenings that last less than 180s) and one that does not (not-SW). Results SW and not-SW methods were similar in scoring (96.76% agreement across epochs), although the SW method had better accuracy for differentiating “light”, “deep”, and REM sleep; but produced more false positives in wake detection. The device (SW-method) classified epochs of wake, “light” (N1+N2), “deep” (N3) and REM sleep with 56%, 77%, 46%, and 62% sensitivity, respectively. Bland-Altman analysis showed that the device significantly underestimated “light” (~19min) and “deep” (~26min) sleep. Alcohol consumption enhanced PSG-device discrepancies, in particular for REM sleep (p=0.01). Conclusion Our results indicate promising accuracy in sleep-wake and sleep stage identification for this device, particularly when accounting for short wakes, as compared to PSG. Alcohol consumption, as well as other potential confounders that could affect measurement accuracy should be further investigated. Support This study was supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) grant R21-AA024841 (IMC and MdZ). The content is solely the responsibility of the authors and does not necessarily represent the official views the National Institutes of Health.

Effect of carotid body denervation on arousal response to hypoxia in sleeping dogs

1981 ◽  
Vol 51 (1) ◽  
pp. 40-45 ◽  
Author(s):  
G. Bowes ◽  
E. R. Townsend ◽  
L. F. Kozar ◽  
S. M. Bromley ◽  
E. A. Phillipson
Keyword(s):  
Carotid Body ◽  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Sleep Stage ◽  
Critical Role ◽  
Ventilatory Responses ◽  
Progressive Hypoxia ◽  
Arousal Response ◽  
Arterial O2 Saturation ◽  
Carotid Body Denervation

We studied the arousal and ventilatory responses to hypoxia during sleep in three trained dogs, before and 1–4 wk after carotid body denervation (CBD). During the studies the dogs breathed through a cuffed endotracheal tube inserted via a chronic tracheostomy. Eucapnic progressive hypoxia was induced by a rebreathing technique, and arterial O2 saturation (Sao2) was measured with an ear oximeter. Sleep stage was determined by electroencephalographic and behavioral criteria. Following CBD, all dogs exhibited hypoventilation under resting conditions; hypoxic ventilatory responses during wakefulness, slow-wave sleep (SWS), and rapid-eye-movement (REM) sleep were less than 10% of control. Prior to CBD, hypoxic arousal occurred at Sao2 of 83.2 +/- 4.6% (mean +/- Se) during SWS and 70.6 +/-2.2% in REM sleep. Following CBD, arousal failed to occur during progressive desaturation to 60% in SWS and 50% in REM sleep, at which levels hypoxia was arbitrarily terminated. In a few studies following CBD where rebreathing was allowed to continue, the dogs occasionally failed to arouse at all and require active resuscitation. The results indicate a critical role for the carotid chemoreceptors in mediating the arousal response to hypoxia.

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