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Background: Sleep on the first night in a sleep laboratory is characterized by a lower sleep quality and frequency of rhythmic masticatory muscle activity (RMMA) than that on the second night in moderate to severe sleep bruxism (SB) patients. Objective: The aims of this study was to clarify the physiological factors contributing to the first night effect on oromotor activity during sleep and investigate whether physiological factors involved in the first night effect differed between rhythmic and non‐rhythmic oromotor activities. Methods: Polysomnographic data collected on two consecutive nights from 15 moderate to severe SB subjects (F 7: M 8; age: 23.2 ± 1.3 [mean ± SD] years) were retrospectively analysed. Sleep variables, RMMA and non‐specific masticatory muscle activity (NSMA) were scored in relation to episode types (i.e. phasic or tonic and cluster or isolated), sleep architecture and transient arousals. The relationships between nightly differences in oromotor and sleep variables were assessed. The distribution of oromotor events, arousals, cortical electroencephalographic power, RR intervals and heart rate variability were examined in relation to sleep cycle changes. These variables were compared between the first and second nights and between RMMA and NSMA. Results: Sleep variables showed a lower sleep quality on Night 1 than on Night 2. In comparisons with Night 1, the RMMA index increased by 18.8% (p <.001, the Wilcoxon signed‐rank test) on Night 2, while the NSMA index decreased by 17.9% (p =.041). Changes in the RMMA index did not correlate with those in sleep variables, while changes in the NSMA index correlated with those in arousal‐related variables (p <.001, Spearman's rank correlation). An increase in the RMMA index on Night 2 was found for the cluster type and stage N1 related to sleep cyclic fluctuations in cortical and cardiac activities. In contrast, the decrease in the NSMA index was associated with increases in the isolated type and the occurrence of stage N2 and wakefulness regardless of the sleep cycle. Conclusion: Discrepancies in first night effect on the occurrence of RMMA and NSMA represent unique sleep‐related processes in the genesis of oromotor phenotypes in SB subjects. [ABSTRACT FROM AUTHOR]

Background: Brexpiprazole is an atypical antipsychotic drug widely used in Japan for the treatment of schizophrenia. Previous studies have investigated the therapeutic effects of some antipsychotics on sleep variables; however, to our knowledge, the effects of brexpiprazole on sleep architecture have not been examined in patients with schizophrenia. Therefore, we aimed to exploratorily investigate the effect of brexpiprazole on sleep variables measured by polysomnography in patients with schizophrenia. Methods: This study included 10 patients with schizophrenia who were originally treated with haloperidol alone. Sleep variables of the participants were measured using polysomnography. After excluding those who did not meet the study criteria, seven patients (five men and two women; mean age [SD], 59.0 [10.0] years) were eligible for further analysis. Polysomnography was repeated at 4 weeks after the participants were prescribed brexpiprazole in addition to haloperidol. We compared the sleep architecture of the participants, measured using polysomnography, before and after taking brexpiprazole. Results: Add‐on brexpiprazole significantly prolonged rapid eye movement latency, increased the duration and percentage of stage N2 and stage N3 sleep (min, %), and decreased the duration and percentage of stage rapid eye movement sleep (min, %) at a significance level of nominal p < 0.05. Conclusion: Although not significant after correcting for multiple comparisons, the present results showed that add‐on brexpiprazole could alter the sleep architecture of patients with schizophrenia. Future studies are warranted to replicate these findings and to further investigate the beneficial influence of brexpiprazole on sleep. [ABSTRACT FROM AUTHOR]

Background: The minimum narcolepsy criteria "mean sleep latency (MSL) ≤8 min and ≥2 sleep onset rapid eye movement (REM) periods (SOREMPs) on polysomnography (PSG) and the multiple sleep latency test (MSLT)," according to The International Classification of Sleep Disorders, Third Edition (ICSD-3), are not specific to narcolepsy. Recently, the characteristic sleep stage sequences preceding SOREMPs in narcolepsy have received attention, but their diagnostic utility remains unclear.Methods: We retrospectively reviewed PSG/MSLT records and chart data for 102 Japanese patients with hypersomnia and at least one SOREMP. We examined the sporadic rates of two sleep stage sequences preceding the SOREMPs-wakefulness or stage 1 to REM (W/S1→R) and stage 2 to REM (S2→R)-comparing these between patient groups with narcolepsy type 1 (N = 28), narcolepsy type 2 (N = 19), and other hypersomnia (N = 55). We also examined the utility of three simple indices using the occurrence of W/S1→R SOREMPs for distinguishing between narcolepsy and other hypersomnia in patients who satisfied the minimum narcolepsy criteria.Results: W/S1→R SOREMPs were significantly more frequent in narcolepsy than in other hypersomnia, and this tendency was also observed even in the patients who satisfied the minimum narcolepsy criteria. The three indices had moderate sensitivities and specificities for distinguishing between narcolepsy and other hypersomnia in patients satisfying the minimum narcolepsy criteria.Conclusions: The W/S1→R pattern was observed significantly more frequently in narcolepsy than in other hypersomnia, suggesting it may help with differentiating narcolepsy from other hypersomnia in patients demonstrating the narcolepsy criteria, although its ability to do so may be modest. [ABSTRACT FROM AUTHOR]

Rationale: Obstructive sleep apnea (OSA) can affect not only sleep quality but also sleep duration. Determining the therapeutic effects of continuous positive airway pressure (CPAP) on habitual sleep profiles may shed light on the impact of OSA on sleep duration.Objectives: To determine whether and how CPAP affects habitual sleep duration in patients with OSA.Methods: Assessments of sleep duration and sleep quality were performed on 57 newly diagnosed study subjects with OSA (46 men; median age, 63 yr; apnea-hypopnea index, >20 h-1) at baseline and 3 months after initiation of CPAP therapy. Measurements included in-laboratory sleep tests (polysomnography), assessments of habitual sleep (actigraphy with sleep diary for 7 d), and questionnaires on subjective symptoms (Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and Hospital Anxiety and Depression Scale).Results: Actigraphic night sleep time did not change after CPAP (from 354.0 ± 64.5 min to 353.0 ± 57.0 min; P = 0.87) in the entire group, despite improvements in sleep efficiency and sleep fragmentation. Changes in habitual night sleep duration varied among the participants; habitual night sleep duration increased by 33 minutes (interquartile range, 14-45 min) in 28 participants (sleep time restorers) and decreased by 23 minutes (interquartile range, -48 to -11 min) in 29 participants (sleep time nonrestorers). Subgroup analyses revealed that sleep time restorers were characterized at baseline as having shorter and more fragmented sleep with frequent daytime napping. Nonrestorers were characterized by frequent use of hypnotic drugs and comorbid insomnia, despite longer habitual sleep duration. Actigraphic sleep fragmentation, sleep efficiency, daytime sleepiness, and the frequency of daytime napping were improved after CPAP only in the sleep time restorers, whereas subjective sleep quality was improved in the nonrestorers. Multivariate linear regression showed that shorter baseline night sleep time, baseline daytime napping, and percentage of sleep time under CPAP were positive predictors of the restoration of actigraphic night sleep time, whereas hypnotic use was a negative predictor.Conclusions: Short-term CPAP did not affect habitual night sleep duration in the group as a whole but induced intraindividual changes in relation to phenotypic features of OSA. Clinical trial registered with www.umin.ac.jp (UMIN000012639). [ABSTRACT FROM AUTHOR]

Objective: Obstructive sleep apnea syndrome (OSAS) and insufficient sleep might increase the risk of drowsy driving and sleepiness-related vehicular accidents. This study retrospectively investigated the factors associated with these driving problems, particularly addressing OSAS severity and sleep amounts of affected drivers.Methods: This study examined 161 patients (146 male and 15 female) with OSAS (apnea-hypopnea index [AHI] ≥ 5) who drove on a routine basis and who completed study questionnaires. To investigate factors associated with drowsy driving during the prior year and sleepiness-related vehicular accidents or near-miss events during the prior five years, logistic regression analyses were performed with age, body mass index, monthly driving distance, habitual sleep duration on weekdays, the Japanese version of Epworth Sleepiness Scale score, AHI, and periodic limb movement index as independent variables.Results: Of the patients, 68 (42.2%) reported drowsy driving experiences, and 86 (53.4%) reported sleepiness-related vehicular accidents or near-miss events. Analyses revealed the following: older age (46-65 years, ≥66 years) was negatively associated with drowsy driving (p <0.05, p <0.05), and habitually shorter sleep duration on weekdays (≤6 hours) was positively associated with drowsy driving (p <0.01). Habitual sleep duration of ≤6 hours (p <0.01) and Epworth Sleepiness Scale score of ≥11 (p <0.01) were positively associated with sleepiness-related vehicular accidents and near-miss events. However, AHI was not associated with these driving problems.Conclusion: Insufficient sleep, rather than severity of OSAS, was associated with sleepiness-related driving problems in these Japanese OSAS patients. [ABSTRACT FROM AUTHOR]

Background and Purpose: Falling is an unexpected event for older adults, but few studies have investigated falls related to arousal levels and mobility immediately after waking up in the morning. Therefore, the purpose of this study was to clarify the possible relationship of arousal level and mobility with falls in the early morning hours. Methods: We investigated both arousal levels and mobility of 14 community-dwelling older adults after waking up, from 4:00 am until 2:00 p m . Mobility and arousal levels were evaluated through the following tests: Timed Up and Go, Functional Reach, postural sway, and critical frequency of fusion. Baseline of mobility and arousal levels were measured before sleep and after 5 hours of sleep. Immediately after waking up, each participant's mobility and arousal levels were remeasured and then also remeasured 2 hours later, 6 hours later, and 10 hours later, respectively. Stanford Sleepiness Scale was also chosen to measure the internal state of subjective sleepiness and it was measured 7 times at 2-hour intervals after the participants woke up from sleep. Results: Significant differences were found between before sleep and after awakening in the score of Timed Up and Go test and Stanford Sleepiness Scale. The speed of Timed Up and Go test after awaking was slower than that before sleep. The Stanford Sleepiness Scale showed high states of sleepiness. Conclusion: We found that the decrease in arousal level in the early morning may affect mobility. The awareness of the degree of arousal levels may increase fall prevention in older adults in the early morning hours. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Although sleep problems are a serious public concern, it is not clear if the presence of depression or multiple comorbid conditions has an additive or multiplicative effect on sleep quality. Methods: We conducted a population-based, cross-sectional survey in a rural town in Japan. Multivariable-adjusted linear regression models were used to explore the association between the number of comorbid conditions and the Pittsburgh Sleep Quality Index (PSQI) global score. The association between the number of comorbid conditions and presence of depression, as defined by the five-item Mental Health Inventory (scores⩽60), in those with poor quality sleep (PSQI global score>5) was determined using a non-parametric trend test. Results: Of 5107 respondents, 3403 (mean age: 51.0years, women: 52.6%) were used for the analysis after exclusion of missing PSQI data. The PSQI global score (mean: 4.9) increased as the number of comorbid conditions increased in a linear and statistically significant manner (p <0.0001). The PSQI global score increased by 0.374 for each additional comorbid condition (p <0.0001). Among those with poor sleep quality, the proportion with depression increased significantly and linearly (p <0.0001) as the number of comorbid conditions increased (37.5% for 0 vs. 59.9% for ⩾4 comorbid conditions). Conclusion: The number of comorbid conditions correlated positively with poor sleep quality, and as the number of comorbid conditions increased, the proportion of those also suffering from depression increased. Recognizing the signs of depression in patients with multiple comorbid conditions is important because of its exacerbation of poor sleep quality. [Copyright &y& Elsevier]

We report two cases of young adults sleepwalking. The first was a 19-year-old man whose episode occurred at the end of the first sleep stage 4. The second patient, a 28-year-old man, had episodes after the first and/or second slow wave sleep. Neither patient had epileptic discharges on a polysomnogram. Sleepwalking is diagnosed in only one percent of patients who are seen in our sleep clinic; this rate is lower than that of narcolepsy. In Japan, there have been few case reports of adult sleepwalking. We report these cases to further the study of sleep medicine, in particular of sleepwalking, in Japan. [ABSTRACT FROM AUTHOR]

Sleep-related painful erection is characterized by complaints of recurrent awakening with penile pain during erections, typically occurring during rapid eye movement sleep, followed by severe insomnia. Here, a case of sleep-related painful erection monitoring with nocturnal penile tumescence, the first case report in Japan, is presented. A 66-year-old man without obesity complained of nocturnal penile erections for 4 years. Overnight polysomnography and nocturnal penile tumescence monitoring showed an apnea-hypopnea index of 20 events/h, poor sleep efficiency of 73% and nocturnal awakenings after the second and third rapid eye movement sleep episodes with good rigidity and erection of penis. [ABSTRACT FROM AUTHOR]

Objectives: Non-restorative sleep (NRS) is related to qualitative aspects of sleep. The associations of NRS with exercise (EX; a planned and purposeful activity) and physical activity (PA; daily bodily movement) by gender and age have not yet been clarified. We investigated the associations of EX and/or PA with NRS by gender and age., Design: A cross-sectional study., Setting: The data on gender, age, presence of NRS and engagement in EX and/or PA were obtained from database and questionnaire of specified medical check-ups in FY 2013 in Japan. The analysis was conducted in 2017., Participants: The subjects comprised 90 122 residents (38 603 males and 51 519 females), aged 40-74 years, who had completed the specified medical check-ups., Outcome Measure: The presence of NRS was assessed using a question asking whether or not the subjects usually got enough sleep. NRS was considered to be present when the subjects answered 'No'. Binary logistic regression analysis was used to assess the associations of presence or absence of EX and/or PA with NRS. The OR and 95% CI of NRS prevalence were calculated and compared between those engaged in both EX and PA and the others., Results: Except for 40s and 70s among males and 40s and 50s among females, the absence of EX or PA was associated with higher ORs of NRS than referent. ORs were more than twice compared with the referents in males in their 50s (OR 2.030(95% CI 1.675 to 2.459)) and 60s (OR 2.148(95% CI 1.970 to 2.343)) and females in their 60s (OR 2.142(95% CI 1.994 to 2.302)) when they engaged in neither EX nor PA., Conclusions: Healthcare providers must take into account the similarities and differences in the associations of EX and/or PA with NRS by gender and age when they support people with NRS., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Both obstructive sleep apnea syndrome (OSAS) and sleep bruxism (SB) are commonly related to arousal events. In this study, we examined the effect of SB on the sleep architecture and investigated the relationship between SB and sleep respiratory events in patients with OSAS., Methods: Patients with OSAS (n=67) in whom apnea/hypopnea occurred five or more times per hour were recruited to this study. Healthy volunteers (n=16) were recruited as controls. None of the healthy volunteers had any sleep disorders or medical disorders, nor had they taken any medication or alcohol. Data were collected by standard polysomnography during overnight sleep tests in a dark, quiet room., Results: The frequency of SB was higher in the OSAS than in the control group. The risk of SB was significantly higher in the OSAS than in the control group (odds ratio, 3.96; 95% confidence interval, 1.03-15.20; P<0.05). Apnea/hypopnea and desaturation events occurred significantly more frequently in patients with than without SB. The frequency of the phasic type of SB correlated positively with that of obstructive apnea, micro-arousal, and oxygen desaturation. The frequency of SB events during micro-arousal events consequent on apnea/hypopnea events was significantly higher in the OSAS than in the control group., Conclusions: We found that patients with OSAS have a high risk of SB. In particular, this is the first report relating phasic-type SB to obstructive apnea events. This relationship suggests that improvement in OSAS might prevent exacerbations of SB.

Objective: The aim of the present school-based questionnaire was to analyze the sleep problems of children with developmental disorders, such as pervasive developmental disorder and attention deficit hyperactivity disorder., Methods: The sleep problems of 43 children with developmental disorders were compared with those of 372 healthy children (control group). All children attended one public elementary school in Kurume, Japan; thus, the study avoided the potential bias associated with hospital-based surveys (i.e. a high prevalence of sleep disturbance) and provided a more complete picture of the children's academic performance and family situation compared with a control group under identical conditions. Children's sleep problems were measured with the Japanese version of the Children's Sleep Habits Questionnaire (CSHQ)., Results: Children with developmental disorders had significantly higher total CSHQ scores, as well as mean scores on the parasomnias and sleep breathing subscales, than children in the control group. The total CSHQ score, bedtime resistance, sleep onset delay, and daytime sleepiness worsened with increasing age in children with developmental disorders; in contrast, these parameters were unchanged or became better with age in the control group. In children with developmental disorders, there was a significant association between a higher total CSHQ score and lower academic performance, but no such association was found in the control group. For both groups, children's sleep problems affected their parents' quality of sleep. There were no significant differences in physical, lifestyle, and sleep environmental factors, or in sleep/wake patterns, between the two groups., Conclusions: Children with developmental disorders have poor sleep quality, which may affect academic performance. It is important for physicians to be aware of age-related differences in sleep problems in children with developmental disorders. Further studies are needed to identify the association between sleep quality and school behavioral performance., (Copyright © 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

During the past several decades, obesity has been increasing globally. In Japan, obesity is defined by a BMI of 25 kg/m² or over; 28.6 % of men and 20.6 % of women are obese. Obese people have an increased incidence of developing cardiovascular, renal, and hormonal diseases and sleep disorders. Obese people also have shortened sleep durations. We investigated seasonal differences in melatonin concentrations, heart rates, and heart rate variability during sleep in obese subjects in Japan. Five obese (BMI, 32.0 ± 4.9 kg/m²) and five non-obese (BMI, 23.2 ± 2.9 kg/m²) men participated in this study in the summer and winter. Electrocardiograms were measured continuously overnight in a climatic chamber at 26 °C with a relative humidity of 50 %. Saliva samples for melatonin were collected at 2300 hours, 0200 hours, and 0600 hours. We found that melatonin concentrations during sleep in obese subjects were significantly lower than those in non-obese subjects in the winter. Heart rate during sleep in winter was significantly higher than that in summer in both obese and non-obese subjects. Heart rate variability was not significantly different in the summer and winter in both obese and non-obese subjects. Our results show that decreased nocturnal melatonin concentrations during winter in obese men may be related to higher heart rates, and this may suggest that obese men are at an increased risk of a cardiovascular incident during sleep, especially in the winter.

Objective: We explored differences between professional and non-professional drivers in terms of the factors associated with preferences for generally accepted, effective countermeasures for sleepiness at the wheel--i.e., napping and drinking coffee., Methods: We performed a cross-sectional questionnaire survey. Data from professional (n = 716) and non-professional (n = 3365) drivers were used for analyses., Results: The results showed that professional drivers experienced drowsy driving and traffic accidents due to falling asleep more often than non-professional drivers. Multiple logistic regression analyses showed that variables which may act as aggravating factors for sleepiness (i.e., engagement in shift-work and insufficient sleep) were associated with preferences for these countermeasures among non-professional drivers. In contrast, among professional drivers, being male and having experienced traffic accidents due to drowsy driving were associated with a preference for napping, while longer annual driving distances and shorter periods after the acquisition of driving licenses were associated with drinking coffee., Conclusion: Our results suggest that non-professional drivers are likely to take these effective countermeasures when they feel or have the potential to experience sleepiness at the wheel. However, this tendency was not observed in professional drivers, and it is speculated that they do not use naps as a countermeasure until they have experienced traffic accidents due to drowsy driving. Sleep education for professional drivers and their employers is desirable for preventing drowsy driving-related traffic accidents., (Copyright © 2011 Elsevier B.V. All rights reserved.)

A total of 788 people (aged from 60 to 93 years) living in the Okinawa prefecture, renowned for the long life expectancy of its citizens, were randomly chosen as subjects. A questionnaire based on lifestyle and sleep-health was distributed. Following this, subjects were chosen in groups of nine from the good sleep-health group and then from the poor sleep-health group based on the results of the survey; their physical activities were then recorded using actigraphs for 1 week. This study suggested that lifestyle, such as exercise, walking and short naps, occupies an important position in the maintenance and improvement of sleep-health. It also verified the reliability of the sleep-health risk index and the questionnaire.

The subjects were eight men of the Japanese Antarctic Research Expedition (average age 35.8 years), and 10 healthy people living around Kofu, Japan (28.9 years). They completed a sleep log for 12 to 18 months, and the sleep-wake state was scored in 10-min epochs. Q24 values calculated by chi2 periodgram were low in the Antarctic midwinter. This means that there was difficulty in synchronizing to a 24-h period in the Antarctic midwinter. In Antarctica, sleep onset and offset times were delayed mostly in the midwinter. In Japan, sleep offset time was delayed mostly around the winter solstice.

We investigated the questionnaire study on sleep of junior high school students to estimate the effect of excessive study hours on their sleep time in 1998. A total of 501 students answered the questionnaire. It was noted that most of the students sleep for 6-8 h on weekdays. The majority of the students of the junior high school felt that their sleep is insufficient on weekdays.

Five hundred and twelve students aged from 6 to 18 years were administered the morningness-eveningness questionnaire and a sleep log. The mean morningness-eveningness score decreased with grade; this decrease was significant around the seventh grade. The habitual waking time showed no difference among grades but the habitual bedtime became later with grade; thus, the sleep length on weekdays decreased with grade. The percentage of students falling asleep during school lessons significantly increased from the eighth to 12th grade. We found that a delay of sleep phase, reduction of sleep length, increased daytime sleep, and transition to evening type occurred at around the seventh grade.

A questionnaire concerning their sleep-related lifestyle and mental health was mailed to people aged in their twenties to fifties living in the Fukushima (North East), Tokyo (Central, Metropolitan) and Okayama (West) areas of Japan. We classified the sleeping pattern of 3642 people (1702 men, 1940 women; mean age 41.3+/-10.67) by multivariational analyses (factor analysis and cluster analysis). They were classified into six groups and defined as 'poor sleeper group' (30.0%), 'good sleeper group' (28.3%), 'long sleeper group' (8.2%), 'short sleeper group' (18.5%), 'irregular sleeper group' (11.3%), and 'Delayed Sleep Phase Syndrome group' (3.7%) based on their characteristics of the factor pattern.

Although sleep disturbance is commonly reported in pregnancy, there have been few studies on sleep characteristics in pregnancy. In this study, all women attending the antenatal clinic at Sapporo Medical College Hospital for 1 month during autumn and 3 months during winter were surveyed with a questionnaire and sleep log. Of the 192 patients, 169 (88.0%) stated that sleep was altered from their usual experience. A principal components analysis identified three sleep factors from the ten items in the measure of sleep used (Sleep Log). The three factors were: Sleep Duration and Quality, Insomnia and Daytime Alertness. Although no significant differences across trimesters were found on the three sleep factors, Sleep Duration and Quality, and Insomnia were worst during the first trimester. Sleep normalized in the second trimester, but the third trimester was characterized by increased Insomnia and decreased Daytime Alertness. The most frequent reasons cited by women for sleep alterations were urinary frequency, backache or ache in the hips and fetal movement. Contingency X2 analyses were used to investigate a relationship between the frequency of reporting the reasons and the trimester of pregnancy. Significant increases were found in reporting as the reasons for sleep difficulties, fetal movement in the third trimester, and heartburn, nausea and vomiting in the first trimester. The description of sleep patterns during pregnancy has clinical relevance as sleep alterations in pregnancy are common.

To summarize, SRM induces a state of relaxation as observed by psychological tests and by effects such as increases in the surface temperature of the hands. Such effects tend to occur from an early stage of training. Furthermore, SRM induces a state of "relaxed-alertness" as opposed to a drowsy state. A method to induce such a state of relaxation may be particularly suitable as a method of stress reduction in industrial settings, where a certain degree is vigilance is required. Currently, the authors are applying SRM in an industrial setting, hoping that such methods may result in stress reduction in a high-tech society.