Effects of the low Fowler's sleep position and methazolamide treatment on sleep bruxism: A randomized controlled trial.

Intracranial pressure is one of the determinants of sympathetic activities, and sleep bruxism is associated with increased sympathetic activities. This study aimed to investigate effects of the low Fowler's sleep position and methazolamide treatment on the occurrence of rhythmic masticatory muscle activities/sleep bruxism episodes in patients with sleep bruxism in a randomized controlled trial. Polysomnographic recordings were performed on the patients with sleep bruxism sleeping in the low Fowler's (15°-30°) or supine position (n = 11), and with methazolamide or placebo treatment (100 mg, 3-4 hr before bedtime, P.O., n = 9), and changes in sleep variables and heart rate variance during sleep in the low Fowler's position or with methazolamide treatment were determined. Sleep bruxism index, number of masseter muscle electromyographic bursts per hour of sleep, ratio of rhythmic masticatory muscle activities/sleep bruxism duration to the total sleep duration, index of total limb movements, index of limb movements with rhythmic masticatory muscle activities, and number of sleep bruxism clusters per hour of sleep in the low Fowler's position and after methazolamide intake were significantly smaller (p < 0.05-0.001) than those in the supine position and after placebo intake, respectively. The low-frequency heart rate variance powers during non-rapid eye movement sleep stage 2 (N2) in the low Fowler's position and with methazolamide treatment were significantly lower (p < 0.05) than those during sleep in the supine position and with placebo treatment, respectively. In conclusion, sleep in the low Fowler's position and methazolamide treatment were associated with significant decreases in the occurrence of rhythmic masticatory muscle activities/sleep bruxism episodes, which might be due to a reduction in intracranial pressure and sympathetic activities mainly during non-rapid eye movement sleep stage 2.

Effects of CPAP treatment on electroencephalographic activity in patients with obstructive sleep apnea syndrome during deep sleep: Preliminary findings of a cross-sectional study.

Study objectives: To investigate whether electroencephalographic (EEG) activities during non-rapid eye movement sleep stage 3 (N3) in obstructive sleep apnea syndrome (OSAS) patients were changed with continuous positive airway pressure (CPAP) treatment.Methods: A cross-sectional study of EEG activity during N3 sleep was conducted in 15 patients with moderate to severe OSAS without and with CPAP treatment compared to 15 normal controls. The amplitude, and absolute and relative power of delta, theta, alpha and beta waves as well as the absolute power ratio of slow to fast EEG waves (i.e., absolute power of delta and theta waves/absolute power of alpha and beta waves) and the spectral power density of 0-30 Hz EEG activities were analyzed.Results: CPAP significantly increased N3 sleep, the absolute and relative powers, amplitudes of delta and theta waves, and absolute power ratio of slow to fast EEG waves, but decreased relative alpha and beta powers during N3 sleep. However, there were no significant differences in those parameters between the OSAS patients with CPAP treatment and normal controls.Conclusions: CPAP prolongs N3 sleep and increases the power and amplitude of slow EEG waves during N3 sleep, which indicates an improvement in sleep quality and further provides evidence for recommendation of CPAP treatment for OSAS patients.

Effects of CPAP Treatment on Electroencephalographic Activity in Patients with Obstructive Sleep Apnea Syndrome During Deep Sleep with Consideration of Cyclic Alternating Pattern.

Objective: To investigate whether continuous positive airway pressure (CPAP) treatment would change EEG activities associated with cyclic alternating pattern (CAP subtype A1, A2, and A3) and non-CAP (NCAP) during non-rapid eye movement sleep stage 3 (N3) in patients with obstructive sleep apnea (OSA). Methods: The effects of CPAP treatment on the percentages of sleep stage N3 occupied by the CAP and NCAP, power of EEG waves in the CAP and NCAP were examined in 18 patients with moderate-to-severe OSA undergoing polysomnographic recordings. Results: Apnea and hypopnea index during sleep stage N3 was positively correlated with ratios of phases A2 and A3 duration to total phase A duration [Phase (A2+A3) /Phase A] and negatively correlated with phase A1/phase A. With CPAP treatment, percentages of sleep stage N3 occupied by total CAPs and subtypes A2 and A3, as well as CAP A2 and CAP A3 indexes were significantly decreased while percentages of sleep stage N3 occupied by NCAP (NCAP/N3) and CAP A1 index were significantly increased. In addition, CPAP treatment significantly decreased percentage of respiratory events associated CAPs and increased percentage of non-respiratory related CAPs. Moreover, absolute and relative delta power was significantly increased during phase A1, unchanged during phase A2 and phase B2, and significantly decreased during phases B1, A3 and B3. The absolute power of faster frequency EEG waves in CAPs showed a general trend of decrease. The absolute and relative power of delta waves with amplitudes ≥75 µV, but not <75 µV, was significantly increased. Conclusion: CPAP treatment improves the sleep quality in OSA patients mainly by increasing delta power and decreasing power of higher frequency waves during phase A1, and decreasing CAP A2 and A3 indexes as well as increasing NCAP/N3 and power of delta waves with amplitudes ≥75 µV during NCAP.

Influence of sleep bruxism on QTc interval and QT variability in patients with OSA: A pilot study.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with increases in QT interval corrected for heart rate (QTc interval) and QT variability index (QTVI) and sleep bruxism (SB) is prevalent in OSA patients. OBJECTIVES: To examine whether QTc interval and QT variability were changed during episodes of rhythmic masticatory muscle activities (RMMAs)/SB in SB patients with and without OSA. METHODS: The RR and QTc intervals, and QTVI during RMMAs with or without accompanied limb movements (RMMAs/LMs) in 10 normal controls and 10 SB patients without OSA and during apneic and recovery periods of OSA in 10 SB patients with OSA were analysed. RESULTS: In the SB patients without OSA and controls, QTc intervals and QTVI were significantly increased during RMMAs/LMs compared with those during the 10 s periods (from 10th to 20th s) before the onset and after the offset of RMMAs/LMs, and significantly increased during RMMAs/LMs with awakenings compared with those with microarousals and no arousals. In addition, QTc interval and QTVI were positively correlated with the duration of RMMAs/LMs. Moreover, in the SB patients with OSA, QTc interval and QTVI during the recovery period of OSA events were significantly longer and higher than those during the apneic period regardless of accompanied RMMAs/LMs, and QTc interval and QTVI during the apneic and recovery periods accompanied with RMMAs/LMs were significantly longer and higher than those without accompanied RMMAs/LMs. CONCLUSION: OSA and RMMAs/LMs events were associated with longer QTc intervals and higher QTVI, and RMMAs/LMs might contribute to these changes associated with OSA events accompanied with RMMAs/LMs.

Heart rate changes associated with rhythmic masticatory muscle activities and limb movements in sleep bruxers: Preliminary findings.

Objective: To investigate the relationship of rhythmic masticatory muscle activities (RMMAs) and limb movements (LMs) with heart rate (HR) acceleration. Methods: The amplitude and duration of HR increases, the time to reach peak HR associated with RMMAs/LMs during sleep, duration of movement events, and their relationships with cortical arousal levels were determined in 9 sleep bruxers and 10 normal controls. Results: A total of 48.15% and 49.44% HR increased before the onset of RMMAs/LMs in the sleep bruxers and controls, respectively. All of the parameters of HR increases were significantly different between the sleep bruxers and the controls (p < 0.05-0.001) and between different cortical arousal levels (p < 0.01), and the duration of RMMAs/LMs was positively correlated with the parameters (Sleep bruxers: r2 = 0.18-0.88, p < 0.0001; Controls: r2 = 0.16-0.78, p < 0.0001). Discussion: These data suggest the HR increases are associated with the movement events and changes in cortical arousal levels in the sleep bruxers and controls. Abbreviations: LMs: Limb movements; HR: Heart rate; RMMAs: Rhythmic masticatory muscle activities; SB: Sleep bruxism; PSG: Polysomnographic; EEG: Electroencephalographic; PLMS: Periodic leg movements; SSRIs: Selective serotonin reuptake inhibitors; ECG: Electrocardiographic; EOG: Electrooculographic; EMG: Electromyographic; SD: Standard deviation; Fig: Figure; SEM: Standard error of mean; N1: Non-rapid eye movement sleep stage 1; N2: Non-rapid eye movement sleep stage 2; N3: Non-rapid eye movement sleep stage 3; REM: Rapid eye movement ; NA: No arousal; mAR: Microarousal; AW: Awakening.

Changes in heart rate related to rhythmic masticatory muscle activities and limb movements in patients with sleep bruxism.

Most sleep bruxism (SB) episodes are accompanied by an increase in sympathetic tone and heart rate (HR). To characterise heart rate (HR) changes in relation to rhythmic masticatory muscle activities (RMMAs) in SB patients, polysomnographic recordings were performed on 10 SB patients and 11 normal controls. The duration of movement events, amplitude and duration of HR increases, and time to reach HR peak associated with RMMAs and limb movements (LMs) were determined, and the relationships of the parameters of HR increases with types of movements and RMMAs were analysed. All of the parameters of HR increases associated with three types of movements (RMMAs, RMMAs + LMs and LMs) and masseter activities (phasic, tonic and mixed) were significantly different (two-way ANOVA, P < .001 for all) in both SB patients and controls. The duration of RMMAs/LMs was positively correlated with the parameters (SB patients: R2  = .24-.85, P < .0001; controls: R2  = .23-.68, P < .0001). The amplitude of HR increases was also positively correlated with respiration changes in the SB patients (R2  = .3258, P < .0001) and controls (R2  = .09469, P < .05). The proportions of phasic RMMAs associated with awakenings, microarousals and no cortical arousals were significantly different and so were the proportions of tonic and mixed RMMAs (Friedman's tests, P < .05-.001). The HR increases associated with RMMAs may be intrinsic to the cortical arousal response and autonomic activation, and differences in HR increases associated with different types of movements and RMMAs might be related to the changes in respiration and differences in cortical arousal levels.

Eye movements in relation to rhythmic masticatory muscle activities in patients with sleep bruxism.

OBJECTIVES: To characterize eye movements during rhythmic masticatory muscle activities (RMMAs) in patients with sleep bruxism (SB). METHODS: Polysomnographic (PSG) recordings were performed on SB patients and normal controls during sleep (n = 8 for each group) and wakefulness (n = 9 for each group). The eye movements associated with episodes of RMMAs/SB during sleep and jaw movements during wakefulness were analyzed. RESULTS: During sleep, all episodes of RMMAs/SB in the SB patients and controls were associated with eye movements and most of the RMMAs/SB related slow eye movements (SB patients: 96.29%, 1583/1644; Controls: 97.49%, 543/557) were horizontal in the SB patients and controls. During wakefulness, all of the series of jaw movements were associated with eye movements. Most of cycles of jaw movements (SB patients: 88.89%, 200/225; Controls: 95.11%, 214/225) were associated with slow eye movements and most of the eye movements (SB patients: 52.50%, 105/200; Controls: 61.21%, 131/214) were vertical. There were significant correlations between the durations of episodes of eye movements and RMMAs/SB during sleep and between the duration of episodes of eye movements and duration of series of jaw movements during wakefulness in the SB patients and controls. CONCLUSIONS: Most of RMMAs/SB episodes during sleep and jaw movements during wakefulness are associated with eye movements in SB patients and normal controls.

Sex-differential effects of olanzapine vs. aripiprazole on glucose and lipid metabolism in first-episode schizophrenia

Abstract Objective To compare sex difference in metabolic effect of olanzapine versus aripiprazole on schizophrenia. Methods A twelve-week prospective open-label cohort study to compare four subgroups according to first-episode schizophrenia patients' type of drug usage and sex: female aripiprazole (n = 11), male aripiprazole (n = 11), female olanzapine (n = 10), and male olanzapine (n = 11) for body mass index, fasting serum triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and fasting glucose. Results Aripiprazole may be associated with weight gain in female patients with low-baseline weight. Aripiprazole may have an adverse effect of weight and favorable effects of circulating glucose and lipid on female over male schizophrenia patients. The aripiprazole-induced changes in glucose and lipid may be independent of body fat storage, especially for female schizophrenia patients. Olanzapine may have adverse effects of weight, glucose and lipid profiles on female over male schizophrenic patients. Discussion Our findings fill the gap in knowledge and provide a sex-specific guidance to psychiatrist better tailoring treatment to individual sex-differential characteristics and a key clue to understand the sex-differential mechanism of antipsychotics-induced metabolic dysfunction.

Characterisation of the relationships between rhythmic masticatory muscle activities and limb movements in patients with sleep bruxism.

BACKGROUND: Most rhythmic masticatory muscle activities (RMMAs) have been shown to be accompanied with limb movements (LMs) in sleep bruxism (SB) patients during sleep. OBJECTIVES: To compare the relationships between RMMAs and LMs in SB patients and normal subjects. METHODS: Polysomnographic recordings were performed on eight SB patients and nine normal subjects and the frequencies and durations of RMMAs as well as LMs were determined. Linear regression and correlation analysis were performed to study the relationship between durations of RMMAs and LMs when RMMAs occurred with LMs. RESULTS: Most LMs in SB patients, but not in normal subjects, were accompanied with RMMAs. RMMAs in SB patients were more likely to be isolated, phasic or mixed, while RMMAs in normal subjects were more likely to be tonic. The frequencies of LMs, isolated RMMAs and RMMAs accompanied with LMs in SB patients were significantly higher than those in normal subjects. Furthermore, linear regression and correlation analysis showed that duration of RMMAs was significantly associated with that of LMs when RMMAs occurred with LMs. The duration of RMMAs, when accompanied with LMs, in SB patients was significantly longer than that in normal subjects. CONCLUSIONS: Close relationships between LMs and RMMAs exist in SB patients and normal subjects, and SB episodes may be part of cortical arousal responses and the increased cortical activities associated with SB episodes may not just be localised to the central nervous system (CNS) that controls jaw movements but may also include other parts of CNS that controls LMs.

Companion of oral movements with limb movements in patients with sleep bruxism: preliminary findings.

BACKGROUND: Sleep bruxism (SB) patients show a higher incidence of leg movements than normal subjects. STUDY OBJECTIVES: The study aimed to characterize SB episodes and their relationships with limb movements (LMs). MATERIALS AND METHODS: Polysomnographic (PSG) recordings were performed on eight SB patients. The intervals between the onsets of adjacent SB episodes and LMs were determined and linear correlation analyses were used to estimate the relationship between the SB index and SB episodes in clusters. The Pearson χ2 and partitions of χ2 tests were used to analyze the differences in incidence of SB episodes and clusters in different sleep stages. RESULTS: A majority of SB episodes (85.05%) were found to be accompanied by LMs and among them, 70.52% SB episodes occurred with movements of both upper and lower limbs and most of LMs (70.54%) occurred before the onset of SB episodes. Most of SB episodes especially those accompanied by LMs occurred with microarousals or awakenings. Linear correlation analysis showed a positive correlation between the SB index and SB episodes in clusters (r2 = 0.7027, P = 0.0093). In addition, the percentage of SB episodes in clusters accompanied by LMs was significantly smaller than that of SB episodes not accompanied by LMs (χ2 test, P < 0.001) and the percentage of SB episodes in clusters during REM sleep was significantly smaller than that during NREM sleep (χ2 test, P < 0.0001). CONCLUSIONS: Most SB episodes might not be isolated events, but rather a part of a series of movements second to changes in arousal level.

[Impact of obstructive sleep apnea-hypopnea syndrome on cerebral microbleeds in patients with cerebral infarction].

OBJECTIVE: To investigate the impact of obstructive sleep apnea-hypopnea syndrome (OSAHS) on cerebral microbleeds (CMBs) in patients with cerebral infarction. METHODS: Consecutive patients with acute cerebral infarction who had cerebral microbleeds shown by susceptibility-weighted imaging (SWI) were enrolled to undergo polysomnography (PSG). The patients were divided into two groups, namely non-OSAHS group with apnea-hypopnea index (AHI) less than 5 and OSAHS group with greater AHI, and the clinical and radiological features of cerebral microbleeds were compared between them. RESULTS: Forty-nine patients were enrolled in this study, including 27 (55.1%) with both cerebral infarction and OSAHS and 22 (44.9%) with cerebral infarction but not OSAHS. A comparison of the risk factors showed that hypertension, a smoking history, and a history of stroke were more prevalent in patients with OSAHS than in those without OSAHS (P<0.05). The incidences of subclinical stroke in OSAHS and non-OSAHS patients were 37.0% (10/27) and 9.0% (2/22) (P<0.05), respectively. Neurological imaging revealed a greater number of cerebral microbleeds in OSAHS group than in non-OSAHS group (P<0.05). In OSAHS patients, 77.8% of the microbleeds were distributed in cortical-subcortical areas, 55.6% in the basal ganglia area, and 25.9% in the infratentorial area, as compared to the percentages of 50.0%, 40.9% and 50.0% in non-OSAHS patients, respectively (P<0.05). In OSAHS patients, 40.7% also had leukoaraiosis, and 48.1% had two or more causes, as compared to the percentages of 13.6% and 18.2% in non-OSAHS patients, respectively (P<0.05). CONCLUSIONS: OSAHS can be a risk factor for cerebral microbleeds. Patients with both cerebral infarction and OSAHS tend to have greater and more extensive lesions of cerebral microbleeds, more complicated cause of the disease, and a grater likeliness of stroke recurrence.