Proportion Of Rapid Eye Movement Sleep Research Articles

Polysomnographic characteristics of sleep in adults with and without physician-diagnosed atopic dermatitis: results from the Study of Health in Pomerania

PurposeTo analyze sleep characteristics as measured with polysomnography (PSG) in adults from the general population with and without physician-diagnosed atopic dermatitis (AD).MethodsWe analyzed data from participants from the German population-based Study of Health in Pomerania (SHIP) TREND-0. AD was diagnosed in a standardized skin examination. The following polysomnographic parameters were measured: total sleep duration (min), sleep latency (min), wake after sleep onset (WASO; min), rapid eye movement (REM) latency (min), sleep efficiency (%), total number of wakefulness and movement episodes, stages of sleep (%), and apnea-hypopnea index (AHI). Additionally, the subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). We compared sleep characteristics of participants with and without AD.ResultsAmong 1187 participants, 47 (4.0%) had AD. We found no differences between participants with and without AD in any of the analyzed PSG parameters except for the total number of wakefulness and movement episodes and the percentage of REM sleep. Participants with AD had a higher number of wakefulness and movement episodes, and a lower proportion of REM sleep compared to those without AD. Regarding subjective sleep parameters, no significant differences were found between participants with and without AD.ConclusionOur data do not provide evidence for poor sleep quality in individuals with AD. Major limitations of the study include the unavailability of data on AD severity and the small number of participants with AD. Larger-scaled longitudinal studies considering disease severity and specific AD symptoms with an effect on sleep are required.

Distinct Sleep Alterations in Alcohol Use Disorder Patients with and without Korsakoff's Syndrome: Relationship with Episodic Memory.

Alcohol Use Disorder (AUD) results in sleep disturbances that may have deleterious impacts on cognition, especially on memory. However, little is known about the sleep architecture in patients with Korsakoff's syndrome (KS). This study aims at characterizing sleep disturbances in KS compared to AUD without KS and at specifying the relationships with cognitive impairments. Twenty-nine AUD patients (22 without KS and 7 with KS) and 15 healthy controls underwent a neuropsychological assessment and a polysomnography. The severity of sleep-disordered breathing and sleep fragmentation was similar in AUD and KS patients compared to controls. Sleep architecture differed between both patient groups: the proportion of slow-wave sleep was reduced in AUD patients only, while a lower proportion of rapid-eye movement (REM) sleep was specifically observed in KS patients. The proportion of REM sleep correlated with the severity of episodic memory deficits when AUD and KS were examined together. These data provide evidence for both similarities and specificities regarding sleep alterations in AUD patients with and without KS. They also indicate that altered sleep architecture may contribute to the pathophysiology of alcohol-related memory disorders.

A Preliminary Study of the Effect of Mattress Temperature on the Subjective and Objective Sleep Quality of Healthy Young Adults

Objective: We evaluated the effects of microclimate temperature on the subjective and objective sleep quality of healthy young adults. For this purpose, we maintained a constant ambient temperature and manipulated the mattress temperature to change the microclimate.Methods: We enrolled 34 healthy young adults (12 males and 22 females; mean age: 24.06±2.70 years). Data from 26 individuals were analyzed (8 males and 18 females; mean age: 23.46±2.40 years). Nocturnal polysomnography (nPSG) was performed and self-reported questionnaires were completed at an ambient temperature of 27°C and mattress temperature of 28°C, 30°C, or 32°C.Results: The subjective sleep satisfaction was lower at a mattress temperature of 32°C than at 28°C. The subjective sleep latency was longer at 32°C than at 30°C. The number of respondents that selected sleep environment (including temperature) as the cause of sleep dissatisfaction was greater at higher temperatures. Participants felt that the mattress temperature was the least cool when they woke up at 32° than 30°C. Furthermore, they reported that the sleep latency at 32°C was longer than the other temperatures compared to usual sleep, and that they had more frequent awakenings at 32°C than at 28°C. The nPSG results showed that the proportion of rapid eye movement (REM) sleep was lower at 28°C than at 30°C.Conclusion: A high microclimate temperature caused by a high mattress temperature was associated with poor subjective sleep quality. Mattress temperature was also related to the objective proportion of REM sleep; however, the results are inconsistent with previous findings. Additional large-scale studies that evaluate a wider temperature range are required.

Fatigue correlates with sleep disturbances in Parkinson disease

Background:Many Parkinson disease (PD) patients complain about chronic fatigue and sleep disturbances during the night. The objective of this study is to determine the relationship between fatigue and sleep disturbances by using polysomnography (PSG) in PD patients.Methods:Two hundred and thirty-two PD patients (152 with mild fatigue and 80 with severe fatigue) were recruited in this study. Demographic information and clinical symptoms were collected. Fatigue severity scale (FSS) was applied to evaluate the severity of fatigue, and PSG was conducted in all PD patients. FSS ≥4 was defined as severe fatigue, and FSS <4 was defined as mild fatigue. Multivariate logistic regression and linear regression models were used to investigate the associations between fatigue and sleep disturbances.Results:Patients with severe fatigue tended to have a longer duration of disease, higher Unified Parkinson Disease Rating Scale score, more advanced Hoehn and Yahr stage, higher daily levodopa equivalent dose, worse depression, anxiety, and higher daytime sleepiness score. In addition, they had lower percentage of rapid eye movement (REM) sleep (P = 0.009) and were more likely to have REM sleep behavior disorder (RBD) (P = 0.018). Multivariate logistic regression analyses found that the presence of RBD and proportion of REM sleep were the independent predictors for fatigue. After the adjustment of age, sex, duration, body mass index, severity of disease, scores of Hamilton Rating Scale for Depression, Hamilton Anxiety Rating Scale, and other sleep disorders, proportion of REM sleep and degree of REM sleep without atonia in patients with PD were still associated with FSS score.Conclusion:Considering the association between fatigue, RBD, and the altered sleep architecture, fatigue is a special subtype in PD and more studies should be focused on this debilitating symptom.

Postsession Dreaming in Neurofeedback as an Indication of Nondeclarative Learning

Clients may report increased dreaming following neurofeedback sessions. Increased dreaming may not be strictly a side effect of training but may rather be a result of the nondeclarative learning accomplished in training. Research has demonstrated the connection between dreaming and consolidation of memory in both animals and human subjects. Rapid eye movement (REM) deprivation studies have shown the importance of REM sleep to the retention of newly learned skills. Other studies have shown that learning may increase the proportion of REM sleep on subsequent nights. More specifically, REM dreaming may be related to the consolidation of procedural, nondeclarative memory, the type of learning that occurs also during neurofeedback training. When a client reports increased nocturnal dreaming following a neurofeedback session, this may serve as a valuable early indication that their brain is responding to this type of training.

Influence of rapid eye movement sleep on all-cause mortality: a community-based cohort study.

Introduction: Although the proportion and duration of rapid eye movement (REM) sleep are correlated with neurological and cardiovascular diseases, whether REM sleep is associated with all-cause mortality in community-based populations remains unknown.Methods: A prospective study was performed within the Sleep Heart Health Study (SHHS, Registration NO. NCT00005275). Total sleep time, sleep efficiency, and REM sleep were measured using polysomnography. Cox proportional hazards regression models were used to estimate the association of the REM sleep with all-cause mortality.Results: Over a mean follow-up period of 11.0 ± 3.1 y, 1234 individuals (21.9%) died. In the entire population, reduced REM sleep was significantly associated with increasing all-cause mortality. After adjustment for age, sex, race, body mass index, smoking status, total cholesterol, triglycerides, high-density lipoprotein, history of diabetes and hypertension, and the apnea–hypopnea index, the duration and proportion of REM sleep were found to be significantly associated with all-cause mortality when the lowest and the highest REM quartile groups were compared (hazard ratio, 95% confidence interval: 1.727, 1.434-2.079; 1.545, 1.298-1.839; respectively).Conclusion: The proportion and duration of REM sleep are negatively associated with all-cause mortality. This finding emphasizes the importance of personalized sleep management in community-based populations.

Schizotypal traits are associated with sleep spindles and rapid eye movement in adolescence.

Research suggests an association between schizophrenia and a decrease in sleep spindle activity, as well as a change in sleep architecture. It is unknown how the continuum of psychotic symptoms relates to different features in the sleep electroencephalogram. We set out to examine how sleep architecture and stage 2 spindle activity are associated with schizotypy in a healthy adolescent population. The participants in our study (n=176, 61% girls) came from a community-based cohort. Schizotypal traits were evaluated using the Schizotypal Personality Scale (STA) in early adolescence (mean age 12.3years, SD=0.5) and the participants underwent ambulatory overnight polysomnography at mean age 16.9years (SD=0.1). Sleep was scored in 30-s epochs into stages 1, 2, 3 and rapid eye movement (REM) sleep. Stage 2 spindles were detected using an automated algorithm. Spindle analyses from central and frontal derivations included spindle duration and density for slow (10-13Hz) and fast (13-16Hz) ranges. Covariates included sex and age. Those with the highest STA scores had a higher percentage of REM (B=2.07 [95% CI, 0.17, 4.0]; p=.03) than those with the lowest scores. Those with the highest scores had shorter spindle duration, as derived from the frontal regions, and a slower oscillation range (B=-0.04 [95% CI, -0.07, -0.01]; p=.023) than those with the lowest scores. We conclude that high levels of schizotypy characteristics measured in early adolescence may be associated with distinguished features of sleep architecture, namely with spindle morphology and a higher proportion of REM sleep.

Sleep in a comparative context: Investigating how human sleep differs from sleep in other primates

Primates vary in their sleep durations and, remarkably, humans sleep the least per 24-hr period of the 30 primates that have been studied. Using phylogenetic methods that quantitatively situate human phenotypes within a broader primate comparative context, we investigated the evolution of human sleep architecture, focusing on: total sleep duration, rapid eye movement (REM) sleep duration, non-rapid eye movement (NREM) sleep duration, and proportion of sleep in REM. We used two different Bayesian methods: phylogenetic prediction based on phylogenetic generalized least squares and a multistate Onrstein-Uhlenbeck (OU) evolutionary model of random drift and stabilizing selection. Phylogenetic prediction confirmed that humans sleep less than predicted for a primate of our body mass, predation risk, brain size, foraging needs, sexual selection, and diet. These analyses further revealed that humans pack an unexpectedly higher proportion of REM sleep within a shorter overall sleep duration, and do so by reducing NREM sleep (rather than increasing REM). The OU model generally confirmed these findings, with shifts along the human lineage inferred for TST, NREM, and proportion of REM, but not for REM. We propose that the risks and opportunity costs of sleep are responsible for shorter sleep durations in humans, with risks arising from terrestrial sleep involving threats from predators and conspecifics, and opportunity costs because time spent sleeping could be used for learning, creating material objects, and socializing.

Sophisticated sleep improves our brains: Our advanced cognitive and social skills might derive from the evolution of improved sleep quality; today, sleep therapy could help with mental health issues and learning.

In the past decades, sleep researchers have been quietly accumulating knowledge about the physiology of sleep. Without any real health application for this knowledge, however, the public and the press have slept blissfully through most of their breakthroughs. Yet, recent findings about the evolution of sleep in humans and the effects of sleep disruption on human health seem to have finally woken the public up. A recent paper from David Samson and Charles Nunn, evolutionary anthropologists from Duke University in the USA, puts forward the hypothesis that humans have evolved more efficient sleep patterns than other primates and that this is because “[e]arly humans experienced selective pressure to fulfill sleep needs in the shortest time possible” [1]. This efficient slumber, the authors argue, might have contributed to setting our ancestors on the evolutionary path toward human civilization. The New York Times , among other newspapers, covered the publication, which follows in the wake of research indicating that human sleep patterns have stayed largely stable during the course of human evolution, from hunter‐gatherers to modern city dwellers [2]. Both of these insights provide evolutionary context for the health impact of too little sleep, with both epidemiological and clinical research showing that sleep disruption has a negative effect on health and well‐being. More recently, however, there is evidence that sleep has distinctly positive therapeutic potential to treat a variety of phobias and other psychotic conditions. The evolutionary study that attracted media attention raises interesting questions about the co‐evolution of sleep and human cognitive faculties. Samson and Nunn suggest that sleep became subject to strong selective pressures—“including increased predation risk […] threats from intergroup conflict, and benefits arising from increased social interaction” [1]—when our ancestors moved down from the trees and onto the savannah. As a result, …

Clinical Considerations of Obstructive Sleep Apnea with Little REM Sleep.

Background and PurposeObstructive sleep apnea (OSA) is more severe during rapid eye movement (REM) sleep than during non-REM sleep. We aimed to determine the features of patients with OSA who experience little REM sleep.MethodsPatients with a chief complaint of sleep-disordered breathing were enrolled. All subjects underwent overnight polysomnography (PSG) and completed questionnaires on sleep quality. Patients were divided into the following three groups according to the proportion of REM sleep detected in overnight PSG: little REM sleep [REM sleep <20% of total sleep time (TST)], normal REM sleep (20–25% of TST), and excessive REM sleep (>25% of TST). Multiple logistic regression analyses were applied to the data. The success rate of continuous positive airway pressure (CPAP) titration was estimated in these groups.ResultsThe age and body mass index of the patients were 47.9±15.9 years (mean±SD) and 25.2±4.1 kg/m2, respectively. The 902 patients comprised 684 (76%) men and 218 (24%) women. The apnea-hypopnea index (AHI) in the little-REM-sleep group was 22.1±24.4 events/hour, which was significantly higher than those in the other two groups (p<0.05). Multiple logistic regression showed that a higher AHI (p<0.001; odds ratio, 1.512; 95% confidence interval, 1.020–1.812) was independently predictive of little REM sleep. The titration success rate was lower in the little-REM-sleep group than in the normal-REM-sleep group (p=0.038).ConclusionsThe AHI is higher and the success rate of CPAP titration is lower in OSA patients with little REM sleep than those with normal REM sleep.

Association between sleep stages and hunger scores in 36 children

Childhood obesity is a growing health challenge. Recent studies show that children with late bedtime and late awakening are more obese independent of total sleep time. In adolescents and adults, a delayed sleep phase has been associated with higher caloric intake. Furthermore, an adult study showed a positive correlation between REM sleep and energy balance. This relationship has not been demonstrated in children. However, it may be important as a delayed sleep phase would increase the proportion of REM sleep. This study investigated the relationship between hunger score and sleep physiology in a paediatric population. Thirty-six patients referred for a polysomnogram for suspected obstructive sleep apnoea were enrolled in the study. Sleep stages were recorded as part of the polysomnogram. Hunger scores were obtained using a visual analogue scale. Mean age was 9.6 ± 3.5 years. Mean hunger scores were 2.07 ± 2.78. Hunger scores were positively correlated with percentage of total rapid eye movement (REM) sleep (r = 0.438, P < 0.01) and REM sleep duration in minutes (r = 0.471, P < 0.05). Percentage slow wave sleep (SWS) was negatively correlated with hunger score (r = -0.360, P < 0.05). There were no correlations between age, sex, body mass index percentiles, apnoea-hypopnoea index, total sleep time, sleep efficiency, sleep onset latency, stage 2 sleep duration and hunger scores. These findings suggest that delayed bedtime, which increases the proportion of REM sleep and decreases the proportion of SWS, results in higher hunger levels in children.

Declarative memory consolidation during the first night in a sleep lab: The role of REM sleep and cortisol

While the consolidation of declarative memory is supported by slow wave sleep (SWS) in healthy subjects, it has been shown to be associated with rapid eye movement (REM) sleep in patients with insomnia. Sleep during a subject's first night in an unfamiliar environment is often disturbed, and this so-called first-night effect (FNE) has often been used as a model of transient insomnia. Additionally, sleeping for the first time in an unfamiliar environment can lead to increased cortisol secretion, and declarative memory consolidation likely depends on low cortisol levels, especially during the early part of the night. Accounting for intersubject variability in the FNE, we examined the relationship between sleep stages, cortisol secretion and declarative memory performance in 27 healthy young men. Declarative memory performance improved significantly after sleep. Whereas memory performance during the learning session and retrieval testing was strongly associated with cortisol secretion, the overnight gain was not. Post hoc analyses indicated that the overnight gain appears to be modulated by the extent of the FNE: a significant overnight improvement in memory performance was found only in subjects with a weak FNE (n=12). In these subjects, no association was found between any sleep stage and the improvement observed in their memory performance. In subjects with a strong FNE (n=12), however, the overnight change in memory performance was associated with the proportion of REM sleep and the total number of REMs. Disturbed sleep in an unfamiliar environment therefore appears to affect the memory consolidation process.

S26-3 Clinical application of PSG to REM sleep behavior disorder and periodic leg movements during sleep

Periodic leg movements during sleep (PLMS) is frequently observed in rapid eye movement (REM) sleep behavior disorder (RBD) especially during REM sleep period. We made a series of studies for investigating the clinical significance and the underlying mechanism of PLMS in RBD. Consecutive 54 patients with idiopathic RBD without PLMS (iRBD w/o PLMS, 65.9±6.9 yrs), 27 patients with iRBD with PLMS (iRBD-PLMS, 67.7±7.1 yrs), and 31 patients with idiopathic PLMS (iPLMS, 63.5±5.9 yrs) were enrolled. Scores of Epworth Sleepiness Scale (ESS) were compared among the three patients groups. PLMS index, mean duration of PLMS, and inter-PLMS interval were calculated during both NREM sleep period and REM sleep period respectively, and compared among the three patient groups. Correlation analysis between ratio of PLMS related arousal index to PLMS index (PLMAI/PLMI) and proportion of REM sleep without atonia to total REM sleep (RWA/REM) were performed in the iRBD-PLMS group. The associated factor for the presence of PLMS during REM sleep period was also investigated in the subject iRBD group. In 15 out of iRBD-PLMS patients, effectiveness of the treatment with pramipexole, a dopamine agonst, was also evaluated. The iRBD-PLMS group showed significantly lower ESS score than the iPLMS w/o PLMS group did. PLMAI/PLMI was negatively correlated with RWA/REM. The iRBD-PLMS group showed significantly higher PLMS index, longer duration of PLMS, and shorter inter-PLMS interval than the iPLMS group did. RWA/REM appeared as a significantly associated factor for the presence of PLMS during REM sleep period among the iRBD patients. However, pramipexole treatment did not show a statistical decrease in the amount of PLMS. Conclusions: RWA could be associated with attenuation of arousal response to PLMS possibly leading to lower daytime sleepiness in iRBD. Our result impresses that PLMS during this sleep period could become an disease process marker of iRBD.

Sleep and delirium after open heart surgery

Abstract The quantity and quality of sleep have been measured objectively in 4 patients before and after open heart surgery; 2 of these became delirious on the third postoperative day. A fifth patient was studied in relation to major abdominal surgery. The degree of sleep disturbance in the early postoperative period was greater after cardiac than abdominal surgery but was not consistently related to the ensuing delirium. Although patients were woken frequently by the necessity for nursing and other care, they were unable to remain asleep when left undisturbed during the period of delirium, which lasted for several days. Rapid eye movement (REM) sleep was absent and delta wave sleep markedly reduced after cardiac surgery and with delirium although the patients described frequent ‘dream-like’ experiences in their drowsy state. Delirium after cardiac surgery difsers from that which sometimes occurs after withdrawal of addictive drugs, when a high proportion of REM sleep is observed.

Sleep in Critically Ill Patients Requiring Mechanical Ventilation

To objectively measure sleep in critically ill patients requiring mechanical ventilation and to define selection criteria for future studies of sleep continuity in this population. Prospective cohort analysis. University teaching hospital medical-surgical ICU. Twenty critically ill (APACHE II [acute physiology and chronic health evaluation II] acute physiology score [APS], 10 +/- 5), mechanically ventilated adults (male 12, female 8, age 62 +/- 15 years) with mild to moderate acute lung injury (lung injury score, 1.8 +/- 0.9) 10 +/- 7 days after admission to the ICU. Patients were divided into three groups based on 24-h polysomnography (PSG) findings. No patient demonstrated normal sleep. In the "disrupted sleep" group (n = 8), electrophysiologic sleep was identified and was distributed throughout the day (6:00 AM to 10:00 PM; 4.0 +/- 2.9 h) and night (10:00 PM to 6:00 AM; 3.0 +/- 1.9 h) with equivalent proportions of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. Nocturnal sleep efficiency was severely reduced (38 +/- 24%) with an increased proportion of stage 1 NREM sleep (40 +/- 28% total sleep time [TST]) and a reduced proportion of REM sleep (10 +/- 14% TST). Severe sleep fragmentation was reflected by a high frequency of arousals (20 +/- 17/h) and awakenings (22 +/- 25/h). Electrophysiologic sleep was not identifiable in the PSG recordings of the remaining patients. These were classified either as "atypical sleep" (n = 5), characterized by transitions from stage 1 NREM to slow wave sleep with a virtual absence of stage 2 NREM and reduced stage REM sleep, or "coma" (n = 7), characterized by > 50% delta or theta EEG activity with (n = 5) and without (n = 2) evidence of EEG activation either spontaneously or in response to deep painful stimuli. The combined atypical sleep and coma groups had a higher APS (13 +/- 4 vs 6 +/- 4) and higher doses of sedative medications than the disrupted sleep group. Sleep, as it is conventionally measured, was identified only in a subgroup of critically ill patients requiring mechanical ventilation and was severely disrupted. We have proposed specific criteria to select patients for future studies to evaluate potential causes of sleep disruption in this population.

Polysomnographic Study in Patients with Severe Myoclonic Epilepsy During Infancy

Purpose: Patients with severe myoclonic epilepsy in infancy (SMEI) exhibit frequent febrile seizures before age 2 years when they show no neurologic deficits. They subsequently develop intractable nonfebrile myoclonic and generalized tonic‐clonic seizures with the appearance of ataxia, developmental delay, and mental retardation. Although its cause remains obscure, the progressive involvement of the cortical as well as subcortical structures has been described. Recently we introduced two indices (tonic inhibition index, TII; and phasic inhibition index, PII) that quantify outputs implicated in motor suppression. These indices were calculated through the standard sleep recording by making use of phasic chin‐muscle activity (PCMA) during rapid‐eye‐movement sleep (REMS). To assess the brainstem involvement in SMEI, these indices were examined in patients with SMEI. Methods: Five polysomnograms obtained from three patients aged from 9 to 25 months were examined. Each polygram consisted of electroencephalography, bipolar horizontal electrooculography, and surface electromyography including the chin muscle. In addition to the proportion of sleep stages in the total sleep time, the TII and PII were calculated. These parameters were compared with those obtained from the age‐matched controls (n = 12). PCMA was defined as a phasic chin‐muscle activity that lasted ≥ 2 s, with a peak amplitude of ≤ 50% above the baseline. TII is the rate of a short PCMA during REMS among the total numbers of PCMA during REMS. The short and long PCMA were separated at a duration of 0.5 s. TII expresses the degree of shortness of PCMA during REMS. PII is a geometric means of the following two values in REMS: (a) the percentage of PCMA that occurs with bursts of rapid eye movements (RBs) in relation to the total number of PCMA, and (b) the percentage of RBs that appear with PCMA in relation to the total number of RBs. As long as rapid eye movement‐related phasic inhibition acts on the chin muscle, PCMA is unlikely to appear in association with RBs. PII expresses the rate of the simultaneous occurrence of PCMA and RBs. Results: With the progression of age, the proportion of REMS and of slow‐wave sleep stages in patients gradually showed values lower than those in controls. The mean TII value in patients (0.66; SD, 0.08) did not differ significantly from that in controls (0.63; SD, 0.05). After 100 weeks of postconceptional age, the mean PII value in patients (7.83; SD, 2.11) was significantly higher than that in controls (4.52; SD, 2.32), whereas there was no difference between the patients (5.8) and controls (5.30; SD, 2.75) at earlier ages. Moreover, in contrast to the controls, PII increased with age in the patients. Conclusions: Although the decrease in the amount of REMS and slow‐wave sleep stages might reflect subcortical impairments, the responsible regions for these findings are uncertain. Because PII decreases during infancy in controls, an increase of PII with age in patients with SMEI suggests a progressive involvement of the neuronal systems. The mesopontine tegmentum plays key roles in the occurrence of rapid eye movement‐related phasic motor reduction, which is responsible for determining the PII value. The pontine as well as rostra1 and caudal medullary atonia zones are crucial for determining the TII value; however, an impairment of these brainstem atonia zones might also affect the PII value. Because TII values remain unaffected in our patients, we conclude that the mesopontine tegmentum is progressively disturbed in patients with SMEI.

Abnormal REM sleep in the irritable bowel syndrome

Motor abnormalities of the small bowel that occur only during the waking state have been reported in the irritable bowel syndrome (IBS), suggesting that central nervous system arousal is a necessary condition for expression of the disorder and that it may reflect inappropriate brain-gut interaction. This possible relationship was explored further by synchronous polysomnography and recording of upper small bowel motility in six healthy subjects and six patients with IBS. During sleep, there was no difference in the patterns of intestinal motility between the two groups. There was no difference between the rapid eye movement (REM) latency or number of REM episodes, but the proportion of REM sleep was markedly increased (36.5% ± 5.7% vs. 18.2% ± 5.7%; P < 0.01) in the IBS group, although the duration of sleep was similar (468 ± 13 minutes in IBS vs. 444 ± 10 minutes in controls; P > 0.1). Sleep apnea was detected in three of six patients with IBS but was not seen in controls. The data are consistent with the model of IBS as a disorder of brain-gut interaction.