The impact of sleep components, quality and patterns on glymphatic system functioning in healthy adults: A systematic review.

OBJECTIVE: The glymphatic system is thought to be responsible for waste clearance in the brain. As it is primarily active during sleep, different components of sleep, subjective sleep quality, and sleep patterns may contribute to glymphatic functioning. This systematic review aimed at exploring the effect of sleep components, sleep quality, and sleep patterns on outcomes associated with the glymphatic system in healthy adults. METHODS: PubMed®, Scopus, and Web of Science were searched for studies published in English until December 2021. Articles subjectively or objectively investigating sleep components (total sleep time, time in bed, sleep efficiency, sleep onset latency, wake-up after sleep onset, sleep stage, awakenings), sleep quality, or sleep pattern in healthy individuals, on outcomes associated with glymphatic system (levels of amyloid-ß, tau, α-synuclein; cerebrospinal fluid, perivascular spaces; apolipoprotein E) were selected. RESULTS: Out of 8359 records screened, 51 studies were included. Overall, contradictory findings were observed according to different sleep assessment method. The most frequently assessed sleep parameters were total sleep time, sleep quality, and sleep efficiency. No association was found between sleep efficiency and amyloid-ß, and between slow-wave activity and tau. Most of the studies did not find any correlation between total sleep time and amyloid-ß nor tau level. Opposing results correlated sleep quality with amyloid-ß and tau. CONCLUSIONS: This review highlighted inconsistent results across the studies; as such, the specific association between the glymphatic system and sleep parameters in healthy adults remains poorly understood. Due to the heterogeneity of sleep assessment methods and the self-reported data representing the majority of the observations, future studies with universal study design and sleep methodology in healthy individuals are advocated.

Sleep Problems in Preschoolers With Autism Spectrum Disorder Are Associated With Sensory Sensitivities and Thalamocortical Overconnectivity.

BACKGROUND: Projections between the thalamus and sensory cortices are established early in development and play an important role in regulating sleep as well as in relaying sensory information to the cortex. Atypical thalamocortical functional connectivity frequently observed in children with autism spectrum disorder (ASD) might therefore be linked to sensory and sleep problems common in ASD. METHODS: Here, we investigated the relationship between auditory-thalamic functional connectivity measured during natural sleep functional magnetic resonance imaging, sleep problems, and sound sensitivities in 70 toddlers and preschoolers (1.5-5 years old) with ASD compared with a matched group of 46 typically developing children. RESULTS: In children with ASD, sleep problems and sensory sensitivities were positively correlated, and increased sleep latency was associated with overconnectivity between the thalamus and auditory cortex in a subsample with high-quality magnetic resonance imaging data (n = 29). In addition, auditory cortex blood oxygen level-dependent signal amplitude was elevated in children with ASD, potentially reflecting reduced sensory gating or a lack of auditory habituation during natural sleep. CONCLUSIONS: These findings indicate that atypical thalamocortical functional connectivity can be detected early in development and may play a crucial role in sleep problems and sensory sensitivities in ASD.

Sleep Problems Prior to Radio-chemotherapy in Patients With Locally Advanced Cancer of the Esophagus or the Esophagogastric Junction.

BACKGROUND/AIM: Many patients with locally advanced cancer of the esophagus or esophagogastric junction receive definitive or neoadjuvant radiochemotherapy. Patient anticipation of this treatment can cause or aggravate distress and sleep disorders. This study aimed to identify the prevalence of sleep disorders and risk factors. PATIENTS AND METHODS: Thirty-eight patients assigned to radio-chemotherapy were retrospectively evaluated for pre-treatment sleep disorders. Investigated characteristics included age; sex; performance score; comorbidity index; previous malignancies; family history; distress score; emotional, physical or practical problems; tumor site; histology and grading; tumor stage; planned treatment; and relation to 2019 Coronavirus pandemic. RESULTS: Sleep problems were reported by 15 patients (39.5%). Significant associations were found for higher distress scores (p=0.016) and greater numbers of emotional problems (p<0.0001). A trend was observed for greater numbers of physical problems (p=0.176). CONCLUSION: The prevalence of sleep problems was high. Risk factors were found that can help identify patients requiring psychological support already prior to radio-chemotherapy.

Sleep Disturbance and Alzheimer's Disease: The Glial Connection.

Poor quality and quantity of sleep are very common in elderly people throughout the world. Growing evidence has suggested that sleep disturbances could accelerate the process of neurodegeneration. Recent reports have shown a positive correlation between sleep deprivation and amyloid-ß (Aß)/tau aggregation in the brain of Alzheimer's patients. Glial cells have long been implicated in the progression of Alzheimer's disease (AD) and recent findings have also suggested their role in regulating sleep homeostasis. However, how glial cells control the sleep-wake balance and exactly how disturbed sleep may act as a trigger for Alzheimer's or other neurological disorders have recently gotten attention. In an attempt to connect the dots, the present review has highlighted the role of glia-derived sleep regulatory molecules in AD pathogenesis. Role of glia in sleep disturbance and Alzheimer's progression.

Neural correlates of sleep quality in children: Sex-specific associations shown by brain diffusion tractography.

BACKGROUND AND PURPOSE: Sleep quality is important for healthy growth and development of children. We aimed to identify associations between sleep disturbances in healthy children without clinical diagnosis of sleep disorders and brain white matter (WM) microstructure using an advanced diffusion-weighted magnetic resonance imaging (DW-MRI) based tractography analysis, and to explore whether there are sex differences in these associations. METHODS: Brain DW-MRI data were collected from sixty-two 8-year-old children (28 boys, 34 girls) whose parents also completed Children's Sleep Habits Questionnaire (CSHQ). Track-weighted imaging (TWI) measures were computed from the DW-MRI data for 37 WM tracts in each subject. Sex-specific partial correlation analyses were performed to evaluate correlations between TWI measures and a set of sleep disturbance scores derived from the CSHQ. RESULTS: Significant correlations (P < .05, FDR-corrected; r: .48-.67) were identified in 13 WM tracts between TWI and sleep disturbance scores. Sexually dimorphic differences in correlations between sleep disturbance scores and WM microstructure measurements were observed. Specifically, in boys, daytime sleepiness positively correlated with track-weighted mean or radial diffusivity in 10 WM tracts (bilateral arcuate fasciculus, left cingulum, right middle longitudinal fasciculus, and three bilateral segments of superior longitudinal fasciculus). In girls, total CSHQ score, night walking, or sleep onset delay negatively correlated with track-weighted fractional anisotropy or axial diffusivity in 4 WM tracts (bilateral inferior longitudinal fasciculus and uncinate fasciculus). CONCLUSIONS: The findings suggest that sleep disturbances without clinical diagnosis of sleep disorders are associated with lower WM microstructural integrity in children. Additionally, the associations possess unique patterns in boys and girls.

Sleep duration, sleep problems, and perceived stress are associated with hippocampal subfield volumes in later life: findings from The Irish Longitudinal Study on Ageing.

STUDY OBJECTIVES: This study examines the cross-sectional and 2-year follow-up relationships between sleep and stress and total hippocampal volume and hippocampal subfield volumes among older adults. METHODS: Four hundred seventeen adults (aged 68.8 ± 7.3; 54% women) from the Irish Longitudinal Study on Ageing completed an interview, a questionnaire, and multiparametric brain magnetic resonance imaging. The relationships between self-reported sleep duration, sleep problems, perceived stress, and total hippocampal volume were examined by using ordinary least squares regressions. Linear mixed-effects models were used to investigate the relationships between sleep duration, sleep problems, perceived stress, changes in these measures over 2-years, and hippocampal subfield volumes. RESULTS: No cross-sectional and follow-up associations between sleep and total hippocampal volume and between stress and total hippocampal volume were found. By contrast, Long sleep (≥9-10 h/night) was associated with smaller volumes of molecular layer, hippocampal tail, presubiculum, and subiculum. The co-occurrence of Short sleep (≤6 h) and perceived stress was associated with smaller cornu ammonis 1, molecular layer, subiculum, and tail. Sleep problems independently and in conjunction with higher stress, and increase in sleep problems over 2 years were associated with smaller volumes of these same subfields. CONCLUSION: Our study highlights the importance of concurrently assessing suboptimal sleep and stress for phenotyping individuals at risk of hippocampal subfield atrophy.

Production of Lactobacillus brevis ProGA28 attenuates stress-related sleep disturbance and modulates the autonomic nervous system and the motor response in anxiety/depression behavioral tests in Wistar-Kyoto rats.

AIMS: Many studies have reported that the production of Lactobacillus brevis is beneficial for sleep, but the underlying mechanism remains unclear. Other known beneficial effects of Lactobacillus brevis include improvement of anxious or depressive symptoms and better modulation of the autonomic nervous system, both of which impact sleep. In this study, we investigated whether the sleep benefit of Lactobacillus brevis was associated with the modulating effects on the autonomic nervous system and anxious/depressive symptoms. MAIN METHODS: Wistar-Kyoto rats were fed the production of Lactobacillus brevis (ProGA28) for the last 2 weeks of treatment before being exposed to case exchange (stress-induced insomnia paradigm). Waking, quiet sleep, and paradoxical sleep states were defined based on polysomnographic measurements. Autonomic functioning was assessed by heart rate variability (HRV). A combined behavioral test was used to evaluate anxiety-like or depressive-like behaviors after the following 2 days. KEY FINDINGS: In exposure to the dirty cage, the control group had significant prolongation of sleep latency, sleep loss during the first 2 h, and decreased parasympathetic activity and increased sympathetic activity during quiet sleep, which were significantly mitigated in the ProGA28 group. In behavioral tests, the ProGA28 group exhibited significantly less anxiety/depression-like motor responses in the elevated plus maze test, the forced swimming test, and the three-chamber social interaction test. Less initial sleep loss in the ProGA28 group was related to higher parasympathetic activity during quiet sleep, and shorter sleep latency in both groups was associated with longer time staying in the open arm in the elevated plus maze test. SIGNIFICANCE: These findings suggest that L. brevis ProGA28 can attenuate stress-related sleep disturbance, which may be associated with increased parasympathetic activity and decreased anxiety-like behaviors.

Obesity Exacerbates Irritable Bowel Syndrome-Related Sleep and Psychiatric Disorders in Women With Polycystic Ovary Syndrome.

Background/Objectives: Polycystic ovary syndrome (PCOS) and irritable bowel syndrome (IBS) share similar clinical and psychosocial features. We aimed to investigate the clinical characteristics of IBS in women with PCOS, and its relationship with obesity, metabolic and hormonal profiles, as well as sleep and psychiatric disorders. Subjects/Methods: This is a cross-sectional case-control study of 431 untreated women with PCOS and 259 healthy volunteers. All participants were assessed with a comprehensive clinical evaluation and two questionnaires: the Athens Insomnia Scale (AIS) and the Brief Symptom Rating Scale (BSRS-5). IBS was diagnosed using the Rome III criteria. Obesity was defined as a BMI ≥30 kg/m2. Anthropometric measurements, metabolic, hormonal profiles, and psychosocial morbidities were compared. Results: Women with PCOS were more likely to have IBS (10.7% vs 5.8%, p=0.029) and obesity (29% vs 4%, p<0.001) than healthy volunteers. Mixed-type IBS (IBS-M) was the most common subtype (74%) among patients with PCOS and IBS. There was a higher prevalence of psychiatric morbidities (total BSRS-5 score ≥10) in women with PCOS than in healthy women (11.4% vs 3.5%, p<0.001). Women with PCOS and IBS were more likely to have sleep difficulties (67.4% vs 30.9%, p<0.001) and psychiatric morbidities (21.7% vs 10.1%, p=0.019) than those without IBS. Anthropometrics, metabolic and hormonal profiles were similar between PCOS women with and without IBS. Among women with PCOS, those with both IBS and obesity had the highest risk of developing sleep difficulties (odds ratio: 5.91; 95% confidence interval: 1.77-19.77) and psychiatric distress (odds ratio: 4.39; 95% confidence interval: 1.26-15.29) than those without. Conclusion: Women with PCOS have increased IBS, obesity, sleep and psychiatric disturbances. The presence of IBS in PCOS women is associated with sleep and psychiatric disorders. The coexistence of obesity and IBS exacerbates sleep difficulties and psychiatric distress. Screening and management of IBS and obesity might be warranted to improve sleep and psychiatric disturbances in women with PCOS.

Network Pharmacology-Based and Molecular Docking-Based Analysis of Suanzaoren Decoction for the Treatment of Parkinson's Disease with Sleep Disorder.

This study is aimed at exploring the possible mechanism of action of the Suanzaoren decoction (SZRD) in the treatment of Parkinson's disease with sleep disorder (PDSD) based on network pharmacology and molecular docking. Traditional Chinese Medicine Systems Pharmacology (TCMSP) was used to screen the bioactive components and targets of SZRD, and their targets were standardized using the UniProt platform. The disease targets of "Parkinson's disease (PD)" and "Sleep disorder (SD)" were collected by OMIM, GeneCards, and DisGeNET databases. Thereafter, the protein-protein interaction (PPI) network was constructed using the STRING platform and visualized by Cytoscape (3.7.2) software. Then, the DAVID platform was used to analyze the Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Cytoscape (3.7.2) software was also used to construct the network of the "herb-component-target-pathway." The core active ingredients and core action targets of the drug were verified by molecular docking using AutoDock software. A total of 135 Chinese herbal components and 41 corresponding targets were predicted for the treatment of PDSD using SZRD. Fifteen important signaling pathways were screened, such as the cancer pathway, TNF signaling pathway, PI3K-AKT signaling pathway, HIF-1 signaling pathway, and Toll-like receptor signaling pathway. The results of molecular docking showed that the main active compounds could bind to the representative targets and exhibit good affinity. This study revealed that SZRD has the characteristics and advantages of "multicomponent, multitarget, and multipathway" in the treatment of PDSD; among these, the combination of the main active components of quercetin and kaempferol with the key targets of AKT1, IL6, MAPK1, TP53, and VEGFA may be one of the important mechanisms. This study provides a theoretical basis for further study of the material basis and molecular mechanism of SZRD in the treatment of PDSD.

An observational study investigating the CRY1Δ11 variant associated with delayed sleep-wake patterns and circadian metabolic output.

We conducted an observational research study to collect information on sleep-wake patterns from participants with a confirmed status of the cryptochrome circadian clock 1 (CRY1) splicing variant, CRY1Δ11 c.1657 + 3A > C, and their controls, defined as wild-type (WT) family members. Altogether, 67 participants were enrolled and completed this study in Turkey, recruited from a list of families with at least one CRY1-confirmed member. We measured sleep-wake patterns and metabolic output, specifically time and frequency of bowel movements, for all participants by daily post-sleep diaries over 28 days. The sleep diary measured self-reported bed time, wake time, midpoint of sleep, and latency to persistent sleep (LPS), and accounted for naps and awakenings for religious purposes. Wake time and midpoint of sleep were significantly later in the CRY1Δ11 variant group versus WT, and LPS was significantly greater in participants in the CRY1Δ11 variant group. The mean bed time on all nights of sleep was later in participants with a CRY1Δ11 variant versus WT. Additionally, participants with a CRY1Δ11 variant had significantly affected metabolic outputs, measured by later bowel movements than WT participants. These results demonstrate that, on average, individuals with the studied splicing variant experience pronounced delays in sleep period and circadian-related metabolic processes.

Thyroid Dysfunction and Sleep Disorders.

Thyroid disorders and sleep disorders are common problems in the general population that can affect people of all ages, backgrounds, and sexes, but little is known about their clinical associations. We reviewed the literature assessing the associations between thyroid disease and sleep disorders and noted that hyperthyroidism and hypothyroidism have clinical overlap with sleep conditions such as insomnia, restless legs syndrome, and obstructive sleep apnea. These findings highlight the importance of identifying and managing thyroid dysfunction for patients with these common sleep disorders. Additional research is needed to further understand how thyroid dysfunction affects sleep physiology.

The role of orexin in Alzheimer disease: From sleep-wake disturbance to therapeutic target.

Accumulating evidence has shown that sleep disturbance is a common symptom in Alzheimer's disease (AD), which is regarded as a modifiable risk factor for AD. Orexin is a key modulator of the sleep-wake cycle and has been found to be dysregulated in AD patients. The increased orexin in cerebrospinal fluid (CSF) is associated with decreased sleep efficiency and REM sleep, as well as cognitive impairment in AD patients. The orexin system has profuse projections to brain regions that are implicated in arousal and cognition and has been found to participate in the progression of AD pathology. Conversely the orexin receptor antagonists are able to consolidate sleep and reduce AD pathology. Therefore, improved understanding of the mechanisms linking orexin system, sleep disturbance and AD could make orexin receptor antagonists a promising target for the prevention or treatment of AD.

Changes in Locomotor Activity and Oxidative Stress-Related Factors after the Administration of an Amino Acid Mixture by Generation and Age.

Amino acids, as nutrients, are expected to improve sleep disorders. This study aimed to evaluate the generation- and age-dependent sleep-improving effects of γ-aminobutyric acid (GABA) and 5-hydroxytryptophan (5-HTP) coadministration. The differentially expressed genes and generation-related behavior after the administration of a GABA/5-HTP mixture were measured in a Drosophila model, while age-related changes in gene expression and oxidative stress-related parameters were measured in a mouse model. The GABA/5-HTP-treated group showed significant behavioral changes compared to the other groups. Sequencing revealed that the GABA/5-HTP mixture influenced changes in nervous system-related genes, including those involved in the regulation of the expression of behavioral and synaptic genes. Additionally, total sleep time increased with age, and nighttime sleep time in the first- and third-generation flies was significantly different from that of the control groups. The GABA/5-HTP mixture induced significant changes in the expression of sleep-related receptors in both models. Furthermore, the GABA/5-HTP mixture reduced levels of ROS and ROS reaction products in an age-dependent manner. Therefore, the increase in behavioral changes caused by GABA/5-HTP mixture administration was effective in eliminating ROS activity across generations and ages.

The Assessment of Sleep Quality in Patients Following Valve Repair and Valve Replacement for Infective Endocarditis: A Retrospective Study at a Single Center.

BACKGROUND The aim of this study was to measure sleep quality among patients who underwent infective endocarditis (IE) surgery and identify the risk factors involved in sleep disorders. MATERIAL AND METHODS In this study, we used actigraphy, the Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleep Scale (ESS) to determine the clinical characteristics of sleep disorders in 116 patients with IE who were in rehabilitation after surgery. RESULTS Our results showed that 46 (39.7%) patients had sleep efficiency over 85%, while 70 (60.3%) patients had sleep efficiency below 85%. The correlation analysis showed that sleep efficiency was related to the duration of the disease, with a longer duration leading to lower sleep efficiency (P=0.031). The sleep efficiency of patients with IE following surgery was also affected by alcohol consumption; however, surprisingly, patients with "heavy" alcohol consumption had higher sleep efficiency (P=0.030). We found a significant correlation between sleep efficiency and postoperative interleukin-6 (IL) levels, C-reactive protein (CRP) levels, and preoperative erythrocyte sedimentation rate (P<0.05). No significant correlation was found between brain natriuretic peptide levels and sleep efficiency, PSQI score, or ESS score. Postoperative hemoglobin (Hb) level was associated with sleep efficiency (R=0.194, P=0.036), but there was no statistically significant correlation between the PSQI and ESS scores. Postoperative alanine transaminase (ALT) showed a significant negative correlation with sleep efficiency (R=-0.27, P=0.003). CONCLUSIONS We found a high prevalence of sleep disorders in patients with IE along with an increase in inflammatory factors, including postoperative IL-6, CRP, ALT, and Hb levels.

Hippocampal and Reticulo-Thalamic Parvalbumin Interneurons and Synaptic Re-Organization during Sleep Disorders in the Rat Models of Parkinson's Disease Neuropathology.

We investigated the alterations of hippocampal and reticulo-thalamic (RT) GABAergic parvalbumin (PV) interneurons and their synaptic re-organizations underlying the prodromal local sleep disorders in the distinct rat models of Parkinson's disease (PD). We demonstrated for the first time that REM sleep is a predisposing state for the high-voltage sleep spindles (HVS) induction in all experimental models of PD, particularly during hippocampal REM sleep in the hemiparkinsonian models. There were the opposite underlying alterations of the hippocampal and RT GABAergic PV+ interneurons along with the distinct MAP2 and PSD-95 expressions. Whereas the PD cholinopathy enhanced the number of PV+ interneurons and suppressed the MAP2/PSD-95 expression, the hemiparkinsonism with PD cholinopathy reduced the number of PV+ interneurons and enhanced the MAP2/PSD-95 expression in the hippocampus. Whereas the PD cholinopathy did not alter PV+ interneurons but partially enhanced MAP2 and suppressed PSD-95 expression remotely in the RT, the hemiparkinsonism with PD cholinopathy reduced the PV+ interneurons, enhanced MAP2, and did not change PSD-95 expression remotely in the RT. Our study demonstrates for the first time an important regulatory role of the hippocampal and RT GABAergic PV+ interneurons and the synaptic protein dynamic alterations in the distinct rat models of PD neuropathology.

Brain Mechanisms of COVID-19-Sleep Disorders.

2020 and 2021 have been unprecedented years due to the rapid spread of the modified severe acute respiratory syndrome coronavirus around the world. The coronavirus disease 2019 (COVID-19) causes atypical infiltrated pneumonia with many neurological symptoms, and major sleep changes. The exposure of people to stress, such as social confinement and changes in daily routines, is accompanied by various sleep disturbances, known as 'coronasomnia' phenomenon. Sleep disorders induce neuroinflammation, which promotes the blood-brain barrier (BBB) disruption and entry of antigens and inflammatory factors into the brain. Here, we review findings and trends in sleep research in 2020-2021, demonstrating how COVID-19 and sleep disorders can induce BBB leakage via neuroinflammation, which might contribute to the 'coronasomnia' phenomenon. The new studies suggest that the control of sleep hygiene and quality should be incorporated into the rehabilitation of COVID-19 patients. We also discuss perspective strategies for the prevention of COVID-19-related BBB disorders. We demonstrate that sleep might be a novel biomarker of BBB leakage, and the analysis of sleep EEG patterns can be a breakthrough non-invasive technology for diagnosis of the COVID-19-caused BBB disruption.

Migraine and Sleep-An Unexplained Association?

Migraine and sleep disorders are common chronic diseases in the general population, with significant negative social and economic impacts. The association between both of these phenomena has been observed by clinicians for years and is confirmed by many epidemiological studies. Despite this, the nature of this relationship is still not fully understood. In recent years, there has been rapid progress in understanding the common anatomical structures of and pathogenetic mechanism between sleep and migraine. Based on a literature review, the authors present the current view on this topic as well as ongoing research in this field, with reference to the key points of the biochemical and neurophysiological processes responsible for both these disorders. In the future, a better understanding of these mechanisms will significantly expand the range of treatment options.

Brainstem damage is associated with poorer sleep quality and increased pain in gulf war illness veterans.

AIMS: Gulf War Illness (GWI) is manifested as multiple chronic symptoms, including chronic pain, chronic fatigue, sleep problems, neuropsychiatric disorders, respiratory, gastrointestinal, and skin problems. No single target tissue or unifying pathogenic process has been identified that accounts for this variety of symptoms. The brainstem has been suspected to contribute to this multiple symptomatology. The aim of this study was to assess the role of the brainstem in chronic sleep problems and pain in GWI veterans. MATERIALS AND METHODS: We enrolled 90 veterans (Age = 50 ± 5, 87% Male) who were deployed to the 1990-91 Gulf War and presented with GWI symptoms. Sleep quality was evaluated using the global Pittsburgh Sleep Quality Index. Pain intensities were obtained with the Brief Pain Inventory sum score. Volumes in cortical, subcortical, brainstem, and brainstem subregions and diffusion tensor metrics in 10 bilateral brainstem tracts were tested for correlations with symptom measures. KEY FINDINGS: Poorer sleep quality was significantly correlated with atrophy of the whole brainstem and brainstem subregions (including midbrain, pons, medulla). Poorer sleep quality also significantly correlated with lower fractional anisotropy in the nigrostriatal tract, medial forebrain tract, and the dorsal longitudinal fasciculus. There was a significant correlation between increased pain intensity and decreased fractional anisotropy in the dorsal longitudinal fasciculus. These correlations were not altered after controlling for age, sex, total intracranial volumes, or additional factors, e.g., depression and neurological conditions. SIGNIFICANCE: These findings suggest that the brainstem plays an important role in the aberrant neuromodulation of sleep and pain symptoms in GWI.

Dexmedetomidine alleviates neuroinflammation, restores sleep disorders and neurobehavioral abnormalities in rats with minimal hepatic encephalopathy.

The occurrence and progress of minimal hepatic encephalopathy (MHE) is closely related to the inflammatory response; however, inflammation contributes to behavioral abnormalities and sleep disorders. Dexmedetomidine has anti-inflammatory effects against various diseases. Whether dexmedetomidine improves MHE and the underlying mechanism is yet unclear. The present study aimed to explore the effects of dexmedetomidine on sleep structure, neurobehavior, and brain morphology of MHE rats and investigate its underlying mechanism. A rat MHE model was established by intraperitoneal injection of thioacetamide (TAA). Dexmedetomidine or yohimbine was administered intraperitoneally to investigate the role of α2 adrenoreceptor in the protection conferred by dexmedetomidine. The 24-h sleep, neurobehavioral changes, the liver function, blood ammonia and morphological changes of the liver and brain were assessed. Also, the microglia, astrocytes, neurons, the expression of pro-inflammatory factors (IL-1ß, TNF-α, IL-18), and NLRP3 inflammasomes were detected. The results showed that marked sleep disorders, cognitive impairment, anxiety, abnormal liver function and pathological damage of liver and brain were detected in the MHE rats. The microglia in the prefrontal cortex was highly activated along with the increased expression of pro-inflammatory factors and NLRP3 inflammasomes. Interestingly, dexmedetomidine improved above indicators, however, yohimbine significantly abolished the protection of dexmedetomidine. These findings showed that dexmedetomidine restored the changes in the sleep disorders and neurobehavior in rats and reduced brain damage. The mechanism might be partially related to the activation of α2 adrenergic receptors, reduction of neuroinflammatory response, and inhibition of the activation of microglia and NLRP3/Caspase1 signaling pathway.

Sleep Disorders in Patients With Breast Cancer Prior to a Course of Radiotherapy - Prevalence and Risk Factors.

BACKGROUND/AIM: Most patients with breast cancer are assigned to radiotherapy, which may cause fears leading to sleep disorders. Very few data are available regarding the prevalence of sleep disorders and corresponding risk factors. PATIENTS AND METHODS: Data of 175 patients with breast cancer presenting for adjuvant radiotherapy were retrospectively analyzed. Twenty-three patient and tumor characteristics were investigated for associations with pre-radiotherapy sleep disorders. RESULTS: Seventy-eight patients (44.6%) stated sleep disorders prior to radiotherapy. These were significantly associated with higher distress score (p<0.0001); greater number of emotional (p<0.0001), physical (p<0.0001) or practical problems (p<0.001); and request for psycho-oncological support (p<0.001). Trends were found for worse performance status (p=0.062) and higher comorbidity index (p=0.059). CONCLUSION: Sleep disorders prior to radiotherapy for breast cancer are common. This applies particularly to patients with risk factors including distress due to emotional, physical or practical problems. These patients should be offered psycho-oncological support as soon as possible.