Rapid eye movement sleep and slow wave sleep rebounded and related factors during positive airway pressure therapy.

This study aimed to investigate the clinical characteristics and predictors of increased rapid eye movement (REM) sleep or slow wave sleep (SWS) in patients with obstructive sleep apnea (OSA) following positive airway pressure (PAP) therapy. The study retrospectively analyzed data from patients with OSA who underwent both diagnostic polysomnography (PSG) and pressure titration PSG at the Tangdu Hospital Sleep Medicine Center from 2011-2016. Paired diagnostic PSG and pressure titration studies from 501 patients were included. REM rebound was predicted by a higher oxygen desaturation index, lower REM proportion, higher arousal index, lower mean pulse oxygen saturation (SpO2), higher Epworth sleepiness score and younger age (adjusted R2 = 0.482). The SWS rebound was predicted by a longer total duration of apneas and hypopneas, lower N3 duration, lower SpO2 nadir, lower REM proportion in diagnostic PSG and younger age (adjusted R2 = 0.286). Patients without REM rebound or SWS rebound had a high probability of comorbidities with insomnia and mood complaints. Some parameters (subjective and objective insomnia, excessive daytime sleepiness, age and OSA severity) indicate changes in REM sleep and SWS between diagnostic and titration PSG tests. Treatment of insomnia and mood disorders in patients with OSA may helpful to improve the use PAP.

Effects of transcranial direct current stimulation on performance and recovery sleep during acute sleep deprivation: a pilot study.

BACKGROUND: Previous studies claimed that transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) improves cognition in neuropsychiatric patients with cognitive impairment, schizophrenia, organic hypersomnia, etc, but few studies evaluated the effects of tDCS on cognitive improvement following sleep deprivation. The objective of this study was to determine whether tDCS (anode on the left DLPFC and cathode on the right DLPFC with a 2-mA current for 30 min) improves cognition following sleep deprivation. METHODS: Seven participants received active tDCS and eight participants received sham tDCS when their cognition declined during at least 30 h of sleep deprivation. All participants completed the psychomotor vigilance task, Trail Making Tests A and B, digit cancellation test, Stroop color word test, the Brief Visuospatial Memory Test-Revised and a procedural game every 2 h during the sleep deprivation and after recovery sleep. RESULTS: Compared to the sham stimulation, active tDCS (anode on the left DLPFC and cathode on the right DLPFC at a 2-mA current for 30 min) had beneficial effects on attention, memory, executive function, processing speed, and the ability to inhibit cognitive interference, and improved in subjective drowsiness and fatigue following sleep deprivation. The lasting effect of a single tDCS on cognition during sleep deprivation was greater than 2 h. In all participants, tDCS did not disturb recovery sleep, and cognitive performance recovered to the baseline levels after recovery sleep. CONCLUSIONS: The study results indicate that tDCS can improve cognition following sleep deprivation and does not disturb recovery sleep or cognitive performance after recovery sleep. The possible pathophysiological mechanisms might be related to the modulation of the corticothalamic pathway. We believe that tDCS can be applied in the treatment of sleep disorders involving sleepiness. TRIAL REGISTRATION NUMBER: ChiCTR2000029420. DATE OF REGISTRATION: 2020-1-31.

Association between leg motor restlessness and depression among Chinese males living at high-altitude: the mediating role of insomnia.

OBJECTIVE: Previous research has documented an association between insomnia and depression among patients with restless legs syndrome (RLS)/Willis-Ekbom disease. Given that leg motor restlessness (LMR) is closely related to RLS, the purpose of this study was to investigate the prevalence of insomnia and depression among individuals with LMR. In addition, we examined the associations among LMR, insomnia, and depression in a sample of young Chinese men living in high-altitude areas. METHODS: Chinese military personnel working on the Qinghai Tibet Plateau (Lhasa, an altitude of 3600 m) were recruited in 2019 to complete a series of questionnaires. Participants having the urge to move their legs but not meeting the diagnostic criteria for RLS were classified as having LMR. Hierarchical linear regressions and mediational analyses using the SPSS PROCESS macro in SPSS were conducted to examine the associations among LMR, insomnia, and depression. RESULTS: Of 196 participants, 36 (18%) had LMR. Only 1 participant was diagnosed with RLS. The proportions of participants suffering from insomnia who had LMR and did not have LMR were 44% and 22%, respectively. For depression, the proportions were 47% and 28%, respectively. Results of the hierarchical linear regressions showed that both LMR and depression were associated with increased insomnia symptoms. In addition, results from the mediational analyses indicated that the indirect effect of LMR on depression was significant and accounted for 52% of the total effect. CONCLUSIONS: Participants with LMR had a higher prevalence of insomnia and depression compared with those without LMR. In addition, LMR was correlated with depression, and insomnia played a significant role in this co-occurrence.