Sleep最新文献

Poor sleep quality might contribute to the risk and progression of neurodegenerative disorders via deficient cerebral waste clearance functions during sleep. In this retrospective cross-sectional study, we explore the link between enlarged perivascular spaces (PVS), a putative marker of sleep-dependent glymphatic clearance, with sleep quality and motor symptoms in patients with Parkinson's disease (PD). T2-weighted magnetic resonance imaging (MRI) images of 20 patients and 17 healthy control participants were estimated visually for PVS in the basal ganglia (BG) and centrum semiovale (CSO). The patient group additionally underwent a single-night polysomnography. Readouts included polysomnographic sleep features and slow-wave activity (SWA), a quantitative EEG marker of sleep depth. Associations between PVS counts, PD symptoms (MDS-UPDRS scores), and sleep parameters were evaluated using correlation and regression analyses. Intra- and inter-rater reproducibility was assessed with weighted Cohen`s kappa coefficient. BG and CSO PVS counts in both patients and controls did not differ significantly between groups. In patients, PVS in both brain regions was negatively associated with SWA (1-2 Hz; BG: r(15) = -.58, padj = .015 and CSO: r(15) = -.6, padj = .015). Basal ganglia PVS counts were positively associated with motor symptoms of daily living (IRR = 1.05, CI [1.01, 1.09], p = .007, padj = .026) and antidepressant use (IRR = 1.37, CI [1.05, 1.80], p = .021, padj = .043) after controlling for age. Centrum Semiovale PVS counts in patients were positively associated with a diagnosis of REM sleep behavior disorder (IRR = 1.39, CI [1.06, 1.84], p = .018, padj = .11). These results add to evidence that sleep deterioration may play a role in impairing glymphatic clearance via altered perivascular function, potentially contributing to disease severity in PD patients.

Enhancing the retention of recent memory traces through sleep reactivation is possible via Targeted Memory Reactivation (TMR), involving cueing learned material during post-training sleep. Evidence indicates detectable short-term microstructural changes in the brain within an hour after motor sequence learning, and post-training sleep is believed to contribute to the consolidation of these motor memories, potentially leading to enduring microstructural changes. In this study, we explored how TMR during post-training sleep affects performance gains and delayed microstructural remodeling, using both standard Diffusion Tensor Imaging (DTI) and advanced Neurite Orientation Dispersion & Density Imaging (NODDI). Sixty healthy young adults participated in a five-day protocol, undergoing five Diffusion-Weighted Imaging (DWI) sessions, pre- and post-two motor sequence training sessions, and after a post-training night of either regular sleep (RS) or TMR. Results demonstrated rapid skill acquisition on Day 1, followed by performance stabilization on Day 2, and improvement on Day 5, in both RS and TMR groups. (Re)training induced widespread microstructural changes in motor-related areas, initially involving the hippocampus, followed by a delayed engagement of the caudate nucleus. Mean Diffusivity (MD) changes were accompanied by increased Neurite Density Index (NDI) in the putamen, suggesting increased neurite density, while Free Water Fraction (FWF) reduction indicated glial reorganization. TMR-related structural differences emerged in the dorsolateral prefrontal cortex (DLPFC) on Day 2 and the right cuneus on Day 5, suggesting unique sleep TMR-related neural reorganization patterns. Persistence of practice-related structural changes, although moderated over time, suggest a lasting neural network reorganization, partially mediated by sleep TMR.

Study objectives: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) may improve sleep dysfunction, a common non-motor symptom of Parkinson disease (PD). Improvement in motor symptoms correlates with DBS-suppressed local field potential (LFP) activity, particularly in the beta frequency (13 - 30 Hz). Although well-characterized in the short term, little is known about the innate progression of these oscillations across the sleep-wake cycle. We sought to characterize LFP fluctuations over several days and nights in the home setting in patients chronically treated with DBS.

Methods: LFPs in the beta and alpha frequency range were recorded from the STN in 13 PD subjects (18 hemispheres) over 14.6 (interquartile range 4) days. Sleep and wake were determined by validated actigraphy. We calculated the mean difference between sleep and wakefulness in LFP power (µVp), probability density functions of normalized LFP, and the fraction of overlap between probability density histograms.

Results: STN LFPs showed a consistent fluctuation based on behavioral state. LFP power was higher during wakefulness than during sleep, with little overlap in the magnitude of LFP power between these two states. Delineation of subject activity patterns revealed that LFP variance by time of day was more strongly correlated at night.

Conclusions: STN LFP fluctuations represent a useful measure to distinguish between sleep and wakefulness in PD. These fluctuations can be detected in the home setting using commercially available devices, including in patients who have been treated with DBS for years. This technology may lead to opportunities for closed-loop DBS therapy.

Study objectives: Exploding head syndrome (EHS) is a parasomnia characterized by the perception of loud noises, or explosions inside the head during the sleep-to-wake transition. The prevalence of EHS remains unclear. This survey aimed to elucidate the prevalence of and factors associated with EHS in this cohort.

Methods: As part of the Night in Japan Home Sleep Monitoring Study (NinjaSleep study), a cross-sectional survey was conducted among government employees in Koka City, Shiga Prefecture, Japan, in 2022. Participants were queried regarding their experiences with EHS as defined in the International Classification of Sleep Disorders, 3rd Edition, including sudden loud noises or sensations of explosions, subsequent abrupt awakenings and feelings of fright. Various standardized instruments were employed to evaluate depression, anxiety, insomnia, quality of life, and fatigue.

Results: Of the 2081 employees invited to participate, 1878 completed the survey. After excluding respondents with epilepsy and incomplete responses, 1843 participants were deemed eligible for analysis. Among them, 46 (2.49%) reported experiencing sudden noises or sensations of explosions, with 23 (1.25%) meeting the diagnostic criteria for EHS. The EHS was significantly related to the scores on the Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Athens Insomnia Scale, and Chalder Fatigue Scale, even after adjusting for age, sex, BMI and categorized mean sleep duration.

Conclusion: This study elucidates the prevalence of EHS among the Japanese population and underscores its potential association with insomnia symptoms and various psychological factors.

Study objectives: This study aimed to investigate the effect of dopamine agonists (DA) and Clonazepam on Large Muscle Group Movements during sleep (LMM), a distinct motor phenomenon, in Restless Legs Syndrome (RLS).

Methods: A retrospective analysis was conducted on 51 drug-free adult patients with RLS, divided into three groups: 33 received a DA (pramipexole or ropinirole), 15 received clonazepam, and 18 received a placebo. Each patient underwent two consecutive nocturnal polysomnographic (PSG) recordings: one baseline and one following treatment administration. LMM and periodic leg movements during sleep (PLMS) were scored. Differences between groups were analyzed using ANCOVA, with the International Restless Legs Syndrome Study Group severity scale as a covariate, and within-group changes were assessed using paired t-tests.

Results: At baseline, no significant difference in LMM or PLMS was observed between groups. Following treatment, DA significantly reduced PLMS and periodicity indexes but did not significantly alter LMM indexes, except for a small increase in LMM duration. The placebo group exhibited a significant decrease in LMM index during the second night, potentially reflecting a first-night effect (FNE). Clonazepam did not significantly affect either PLMS or LMM.

Conclusions: DA effectively reduced PLMS but did not significantly impact LMM, suggesting that LMM may involve different neurophysiological mechanisms. The potential FNE observed in the placebo group underscores the need for careful consideration of adaptation effects in sleep studies. Future research should explore alternative or adjunctive therapies targeting LMM and residual sleep disturbances in RLS.