Sleep Cycle Research Articles

Neuroanatomical findings in isolated REM sleep behavior disorder and early Parkinson’s disease: a Voxel-based morphometry study

Isolated rapid eye movement (REM) sleep behavior disorder (iRBD) is a parasomnia characterized by loss of physiological atonia of skeletal muscles with abnormal behaviors arising during REM sleep. RBD is often the early manifestation of neurodegenerative diseases, particularly alpha-synucleinopathies, such as Parkinson’s disease (PD). Both structural and functional neuroimaging studies suggest that iRBD might share, or even precede, some of the features commonly found in PD, although without a definitive conclusion. Aim of the study is to evaluate the presence of structural abnormalities involving cortical and subcortical areas in PD patients with RBD and iRBD. Patients with video-polysomnographic (VPSG)-confirmed iRBD, and patients with a diagnosis of PD were recruited. In all PD patients, the presence of probable RBD was assessed during the follow-up visits (PD/pRBD). A group of healthy controls (HC) subjects was also recruited. Each subject underwent a structural brain MRI using a 3-D T1-weighted spoiled gradient echo sequence. Twenty-three patients with iRBD, 24 PD/pRBD, and 26 HC were enrolled. Voxel-based morphometry-AnCOVA analysis revealed clusters of grey matter changes in iRBD and PD/pRBD compared to HC in several regions, involving mainly the frontal and temporal regions. The involvement of cortical brain structures associated to the control of sleep cycle and REM stage both in PD/pRBD and iRBD might suggest the presence of a common structural platform linking iRBD and PD, although this pattern may not underlie exclusively RBD-related features. Further longitudinal studies are needed to clarify the patterns of changes occurring at different time points of RBD-related neurodegeneration.

Sleep apnea syndrome associated with gonadal hormone imbalance (Review).

Patients with obstructive sleep apnea exhibit an increased risk of developing gonadal disorders. Because a notable number of people worldwide have sleep respiratory and reproductive disorders, it is essential to recognize the association between local upper airway dysfunction and its gonadal effects. Repeated breathing pauses cause sleep fragmentation, disorganization of sleep cycles and stages, sympathetic activation, intermittent hypoxemia and systemic inflammation. Nocturnal intermittent hypoxemia has a direct central effect on neurotransmitters, with disturbances in the normal production of hypothalamic-pituitary hormones. Awakenings and micro-awakenings at the end of apneic episodes produce a central stress responsible for hormonal changes and subsequent endocrine imbalances. The aim of the present study was to investigate the impact of obstructive sleep apnea syndrome (OSAS) on gonadal hormonal homeostasis and its consequences. Recognizing and understanding how local upper airway dysfunction causes gonadal imbalance may facilitate better care for patients with OSAS. Although there may be a direct relationship between sleep-disordered breathing and gonadal function mediated by hormones via the hypothalamic-pituitary-gonadal axis, to date, current therapies have not been effective.

Public health monitoring of behavioural risk factors in USA: An exploratory study

Abstract Background The COVID-19 pandemic's restrictions had a significant impact on behavioural markers such as physical, sedentary and sleep activity. The Behavioral Risk Factor Surveillance System is a key data source for public health surveillance in the USA but is limited by subjectivity and data quality, and new-generation data sources like Fitbits face challenges with battery life and data access. This research study aims to use zero-effort technology and IoT-based big data to evaluate the impact of the COVID-19 pandemic on population-level behavioural changes in USA. Methods The study used a proposed methodology to analyze data from 470 households in New Mexico, USA, using the DYD dataset from Donate your Data initiative by ecobee (a smart thermostat company). The Microsoft Azure data lake is used for the storage of raw data and the Azure databricks is used for data pre-processing, processing, and analysis. The Gaussian mixture model is used to identify sleep parameters by segmenting the sleep cycle records into different clusters. The quantity of sleep is measured by a motion sensor based on the absence of movement, and an increase in sensor activation indicates longer duration of household occupancy. Results The findings show significant changes at the household and population level for the selected behavioural health indicators (sleep-time, wake-up time, time spent indoors, time spent outdoors) during COVID-19 pandemic, which could be attributed to the policy changes implemented to curb the spread of COVID-19. The study findings are shown by 1) heatmap visualizations at the household level showing trends for the selected indicators during the Covid-19 pandemic; and 2) statistical analysis indicating a significant difference in selected behavioural health indicators before and during the pandemic. Conclusions These innovative data analytics have the potential to provide real-time insights and alert system activation to monitor, promote, and improve public health. Key messages • Sleep health analysis using IoT data is a novel method of measuring public health indicators objectively using zero effort technology. • The available evidence from this study can further offer surveillance systems with near-real-time behavioral markers; alert system activation; and measure short- and long-term impact policy changes.

P050 Process O (onset/offset) cause of the 90-min sleep cycle

Abstract The ubiquitous sleep cycles across a normal sleep of approximately 90 minute period length were originally suggested to be a reflection of a 90-minute basic rest-activity cycle (BRAC) operating across the full circadian cycle of wakefulness and sleep. The evidence for a BRAC during the wakeful period is sparce requiring other explanations for the prominent 90min cycles during sleep. Recently another process, Process O (onset/offset), has been suggested in addition to Processes S (homeostatic) and C (circadian). It was hypothesised in order to account for the recuperative effects of a brief power nap, inexplicable by the other two processes. Process O hypothesises a development of inhibition to any ongoing state (wake, NREM, REM). The inhibition develops rapidly over 1-2 hours to a plateaued limited level and then, following the cessation of that state, dissipates rapidly (5-15 minutes). Thus, a “power” nap brings improved alertness because of the short break from wakefulness allowing the dissipation of wakefulness Process O inhibition. It is suggested that Process O inhibition accumulates also to periods of NREM sleep and REM sleep. The ‘sleep switch’ accounting for bi-stable states of sleep or awake is hypothesised to include REM and NREM as separate states accounting for stability and mutual inhibition between 3 rather than just 2 states. Thus Process O inhibition developing to an ongoing state tips the balance to other states (REM or NREM) resulting in the alternation between them of the sleep cycles and allowing longer sleep epochs after brief awakenings.

P047 Slow Wave Dynamics in Mild Cognitive Impairment compared with Age Matched Controls: A High Density EEG study.

Abstract Introduction Slow wave activity during non-rapid eye movement (NREM) sleep has been linked with memory consolidation in healthy older adults. To date, there has been limited research in mild cognitively impaired populations, particularly looking across the whole brain using high density EEG. We aimed to determine if the dynamics of slow wave activity (delta power) during the first NREM sleep cycle differ between patients with mild cognitive impairment (MCI) and healthy older adults. Methods Participants were assessed for MCI by a panel of neuropsychologists and clinicians. They underwent full polysomnography including high-density EEG (256 electrodes). We computed the delta power (0.5-4.5Hz) for each NREM cycle and slope between sleep onset and the peak of delta in the first NREM sleep cycle (rise-rate) which were compared between groups using t-tests. Results 17 older adults with MCI and 21 older healthy controls were assessed. The mean delta power in the first NREM cycle did not differ between MCI and controls across the whole brain, but the global rise-rate (1/min) of MCI and controls was 0.0015 and 0.0032 respectively (t-value -2.35, p=0.025). Discussion Global slow wave dynamics in the first NREM period appear to be altered in patients with MCI compared with age-matched controls. The gentler slope of rise-rate to the first delta peak in MCI patients than in healthy controls may indicate the dysfunction of sleep homeostasis in MCI patients. Regional slow wave dynamics, ultra-low frequency delta (0.25-1Hz), and associations with sleep dependent memory consolidation will further be explored.

A Case Report on Alcohol Dependence Syndrome with Relation to Insomnia

Alcohol dependence is a pattern of substance use, leading to clinically significant impairment or distress; chronic alcohol abuse has been known to disrupt the normal sleep cycle and lead to sleep disorders, including sleep terror disorder. A male patient of age 42 years was a known alcoholic for 24 years, and the patient does not have any previous psychiatric history. Then, he stopped drinking for four days and developed insomnia. The patient gave an account of emotional outbreaks from 2 days; vital signs included blood pressure 140\90 , pulse rate 81 bpm, respiratory rate 20 , and oxygen saturation 97%@RA and the patient's GRBS level was 210 mg\, and the patient was immediately given with medication in. 4mg (IV), . (2 amp in 100 ml NS, BD), . Panto 40mg (IV), the same drug, was continued for three days, and there was no complaint of visual hallucinations. The patient felt symptomatically better and was discharged on the 4th day with no fresh complaints. The patient was advised to continue Tab. 2mg for three days. The preliminary case investigation evaluated the link between insomnia and alcohol dependence syndrome (ADS).

Factors Influencing the Perception and its Impact on Self-rated Health: A Cross-sectional Survey

Objectives: A cross-sectional survey was made on self-rated health, which is a simple and easy-to-administer measure of general health. It is a valid and reliable measure among those without cognitive impairment. Initially, it replaced clinical assessments in survey research and clinical settings. Materials and Methods: This study was a cross-sectional survey and the study was conducted in a community-based online survey of 6-month duration. Psychologically ill patients, pregnant women, and pediatrics were excluded from this study. The sample size was set to be >800, and the collected data were 806. The data was procured from every willing individual in the age group of 18-60 years old. To identify the similarity and variances in their responses, they were correlated with the health rating of the responders. The physicians at RDT Hospital, Bathalapalli, Anantapur, Andhra Pradesh Prepared and validated the data collection form. Results: This study was evaluated to check the impact of health literacy on one’s health. All the factors were included and taken into consideration while framing the questionnaire. The parameters and the respondent’s answers were compared and correlated they were assessed by two-tailed test and significantly correlated using Pearson’s correlation. The self-rating of the health of the responders was found to be 47%. The major factors affecting health are age, gender, body mass index (BMI), occupation, weight profile, work profile, surrounding hygiene, quality of life, physical activity, eating habits, regular sleep cycle, sleep quality, stress factor, psychological and mental health, comorbidities, side effects, nutritional supplements, self-medication or doctor’s prescription, and literacy score. Respondent’s physical activities were collected and found to be 89.7% negative and statistically significant. The BMI of the responders was classified into four categories: Underweight (16.7%), normal (51.86%), overweight (20.09%), and obese (7.94%). It was found to be negatively significant and two-tailed correlated. Conclusion: The study has now provided evidence on what factors influence an individual’s health self-rating and how these factors correlate to influence each other on the same platform.

Was there a significant difference in sleep shifts in the high school population due to the COVID-19 pandemic depending on chronotype? A nationwide cross-sectional study

ABSTRACT The aim of this study was to detect whether the COVID-19 pandemic has caused changes in the sleep cycle (subjective sleep shifts) of high school students divided into a sample of young women – W (n = 1999, age = 17.65 ± 2.39 y) and young men – M (n = 1094, age = 17.49 ± 1.74 y) in Slovakia depending on circadian preference in comparison with the term before COVID-19. The present cross-sectional study employed a self-reported standardized questionnaire (Morningness-Eveningness Questionnaire) to study circadian preference, which was complemented by a question focused on subjective sleep shifts before and during the pandemic. The results revealed significant strong dependence between circadian preference and subjective sleep shift in both W (χ 2 (8) = 153.1, p < .01, Cramer’s V = .20, p < .01) and M (χ 2 (8) = 98.3, p < .01, Cramer’s V =.21, p < .01). The delay of the sleep cycle has mainly become apparent in the case of definite evening types (W: 75.7%; M: 71.8%) and moderate evening types (W: 83.1%; M: 70.3%). The delay also prevailed in the intermediate types (W: 61.9%; M: 53.8%). Subjective sleep shifts were not confirmed (W: 93.8%; M: 35.3%) in the definite morning type. The sleep cycle was changed to earlier hours of definite morning types (W: 6.3%; M: 52.9%). It is necessary to focus on definite and moderate evening types and regulate the unsuitable state to time shift of the sleep cycle.

L-SeqSleepNet: Whole-cycle Long Sequence Modelling for Automatic Sleep Staging.

Human sleep is cyclical with a period of approximately 90 minutes, implying long temporal dependency in the sleep data. Yet, exploring this long-term dependency when developing sleep staging models has remained untouched. In this work, we show that while encoding the logic of a whole sleep cycle is crucial to improve sleep staging performance, the sequential modelling approach in existing state-of-the-art deep learning models are inefficient for that purpose. We thus introduce a method for efficient long sequence modelling and propose a new deep learning model, L-SeqSleepNet, which takes into account whole-cycle sleep information for sleep staging. Evaluating L-SeqSleepNet on four distinct databases of various sizes, we demonstrate state-of-the-art performance obtained by the model over three different EEG setups, including scalp EEG in conventional Polysomnography (PSG), in-ear EEG, and around-the-ear EEG (cEEGrid), even with a single EEG channel input. Our analyses also show that L-SeqSleepNet is able to alleviate the predominance of N2 sleep (the major class in terms of classification) to bring down errors in other sleep stages. Moreover the network becomes much more robust, meaning that for all subjects where the baseline method had exceptionally poor performance, their performance are improved significantly. Finally, the computation time only grows at a sub-linear rate when the sequence length increases.

Study on the protective mechanism of neuropeptide S in neonates with hypoxic ischemic encephalopathy

Hypoxic-ischemic brain damage (HIBD) is a severe complication of neonatal asphyxia that contributes significantly to neonatal mortality, cerebral palsy, and delays in intellectual and motor development. Neuropeptide S (NPS) plays a role in the regulation of various physiological processes. This study aimed to determine the morphological localization of NPS in hypothalamic target neurons during HIBD, providing a basis for further investigation of HIBD. Seven-day-old SD neonatal male rats were assigned to a sham group and a model group to establish the HIBD model. Then, the rats in the model group were further averagely divided into the NPS group and the normal saline group. Immunohistochemical staining of Fos immunoreactivity (Fos-IR) found that NPS administration resulted in a significant increase in the count of Fos-IR neurons in the suprachiasmatic nucleus (122%), paraventricular nucleus (108%), dorsal tuberomammillary nucleus (174% and 386%), ventromedial hypothalamic nucleus (116%), arcuate nucleus (167%), perifornical nucleus (320%), ventral tuberomammillary nucleus (441%), and lateral hypothalamic area (278%) (P &lt; 0.0001), compared to the normal saline group. During HIBD, NPS can protect the above neurons and activate the above target neurons in the hypothalamus to participate in the sleep and wake cycle, mood, diet, circadian rhythm, temperature and neuroendocrine regulation.

Effects of exercise timing and intensity on physiological circadian rhythm and sleep quality: a systematic review.

Humans show near-24-h physiological and behavioral rhythms, which encompass the daily cycle of sleep and wakefulness. Exercise stimulates circadian rhythms, including those of cortisol, melatonin, and core body temperature, and affects sleep quality. We systematically reviewed studies that examined the effects of exercise intensity and timing on physiological circadian rhythms and sleep quality. In this systematic review, we used the online databases PubMed, Science Direct, Web of Science, and Embase. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two independent and experienced systematic reviewers performed the search and selected relevant studies. The participant, intervention, comparison, and outcome characteristics were: (1) adults; (2) exercise treatment; (3) no exercise treatment or different types of exercise (pre-exercise baseline); (4) cortisol, melatonin, or core body temperature measurement, and subjective or objective sleep quality assessments. We identified 9 relevant articles involving 201 participants (77.1% of whom were male). Our review revealed that short-term evening exercise delayed melatonin rhythm and increased nocturnal core body temperature; however, no negative effects on non-rapid eye movement sleep and sleep efficiency were observed. Moreover, no differences in sleep quality were observed between acute high-intensity and moderate-intensity exercises. With long exercise durations, the core body temperature tended to increase and return to baseline levels at 30-120 min. Our review showed that short-term evening exercise and high-intensity exercise did not have a significant negative effect on sleep quality but physiological circadian rhythm tended to alter. Longterm morning exercise tended to decrease cortisol concentrations after awakening and improve sleep quality. Future studies should examine the effects of long-term exercise timing and intensity on circadian rhythm and sleep.

A randomized controlled trial with a combination of low frequency electroacupuncture and cognitive behavioral therapy for short-term insomnia

ObjectiveTo explore the therapeutic effects of low frequency electroacupuncture (EA) combined with cognitive behavioral therapy (CBT) for short-term insomnia. MethodsPatients with “short-term insomnia” were randomly divided into the treatment and control groups. Patients in the treatment group were treated with low-frequency EA combined with CBT, while those in the control group were only treated with low-frequency EA. The Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), and Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS) scores in the two groups were compared before and after treatment within the same group, as well as between the two groups. After four weeks of treatment, the comprehensive therapeutic effects of both treatment modalities and the number of people who developed chronic insomnia were compared. ResultsThe differences in PSQI score, PSQI sleep rate, ISI score, and DBAS score band after treatment, within the same group and between groups were statistically significant. There was significant difference in DBAS score between the two groups before and after treatment, and in the composition ratio of comprehensive therapeutic effects between the two groups. ConclusionLow-frequency EA combined with CBT and low-frequency EA alone can significantly improve sleep cycles in patients with insomnia, reduce the sleep severity index, prevent daytime sleepiness symptoms in patients, and improve cognition in patients. Low-frequency EA combined with CBT had better therapeutic effects and improved cognition in patients, and hence can be recommended.

Nighttime Sleep and Respiratory Disturbances in Individuals Receiving Methadone to Treat Opioid Use Disorder.

Opioids are a leading cause of drug overdose deaths in the United States. Methadone used as medication for opioid use disorder (MOUD) reduces drug cravings and promotes abstinence. However, individuals in methadone-based MOUD treatment commonly report subjective sleep complaints and are at risk for respiratory depression from opioids. We investigated nighttime sleep and respiratory function in eight individuals (six women, two men; ages 31-68 years) in their first 90 days of methadone-based MOUD treatment. Participants underwent overnight cardiorespiratory polysomnography. Sleep and respiratory variables were characterized with descriptive statistics for comparison to reference data from similarly aged healthy adults. Although participants spent 8.1 ± 0.3 hours (mean ± SD ) in bed, their total sleep time was only 6.8 ± 1.3 hours. They exhibited longer sleep latency and intermittent wakefulness. Sleep structure was irregular, with disrupted sleep cycles. Participants also displayed a decreased amount of N1 sleep and an increased amount of N3 sleep, compared with reference data. Participants showed respiratory depression, with an average apnea-hypopnea index of 16.5 ± 8.9 events per hour. Central sleep apneas comprised 69.1% ± 20.9% of the respiratory events. A Cheyne-Stokes-like breathing pattern, consisting of 30-second cycles of three central sleep apneas, was observed in 75% of participants. Our results suggest that individuals early in methadone-based MOUD treatment experience disordered sleep and respiratory disturbances. Such nighttime physiological changes may have serious long-term health consequences and contribute to unintended overdose rates. Identifying and treating MOUD individuals with sleep apnea could reduce risk of death.

A nap consolidates generalized perceptual learning

Previous research has demonstrated that a night's sleep can consolidate rote and generalized perceptual learning. Over a waking retention period following training, performance gains from learning significantly decline, but sleep can restore performance to levels found immediately after learning. Furthermore, when sleep precedes a waking retention period following training, performance is protected against loss. Other research demonstrating that rote learning can be consolidated by a night's sleep has shown that a relatively brief nap can consolidate rote learning. This suggests that short periods of sleep can produce consolidation, indicating that consolidation may not require successive sleep cycles over an entire night to emerge. However, previous research has demonstrated that there can be differences in sleep-dependent consolidation for rote and generalized learning. In this study, we investigated whether an opportunity for a 90-min midday nap was sufficient to consolidate generalized perceptual learning of synthetic speech. We recruited 75 participants from the University of Chicago community (mean age of 20.83) who completed a pretest, training, and posttest in the morning on perception of synthetic speech. Training and testing in this manner are known to result in substantial generalized learning of synthetic speech. Participants then returned in the afternoon and were either given an opportunity for a 90-min nap or remained awake for 90-min. Participants were then given another posttest later that evening, never hearing the same words twice during the experiment. Results demonstrated that participants who did not nap showed significant loss of learning at the evening posttest. In contrast, individuals who napped retained what they learned, and did not show loss of learning at the evening posttest. These results are consistent with the view that an opportunity for a 90-min midday nap can consolidate generalized learning, as only individuals with consolidated learning should be able to retain what they learned despite an intervening waking retention period. This is the first demonstration that generalized skill learning is subject to sleep-dependent consolidation in short durations of sleep and does not require a full night of sleep. This work has implications for understanding the basic neural mechanisms that operate to stabilize short-term learning experiences.

Regulation of REM sleep in mice: The role of dopamine and serotonin function in the basolateral amygdala

Animals have a sleep cycle that involves the repetitive occurrence of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. In a previous study, we discovered that a transient increase in dopamine (DA) levels in the basolateral amygdala (BLA) during NREM sleep terminates NREM sleep and initiates REM sleep by acting on Drd2-positive neurons (Hasegawa et al., 2022). In this study, we identified the neurons activated by the transient increase of DA in the BLA and found that chemogenetic excitation of these neurons increased REM sleep. Additionally, we demonstrated that acute inhibition of serotonin (5HT) in the BLA elicited a transient increase in DA in the BLA, which triggered REM sleep.

Sleep and Fatigue in an Expeditionary Medical Team: Results and Lessons Learned from a Field Study

Sleep deprivation and fatigue can have significant detrimental effects on cognitive and task perform ance during continuous operations. The current study records sleep and wake cycles, fatigue, and cognitive performance of two Marine Corps expeditionary medical teams during a 48-hour field user exercise with a realistic patient stream. The results suggest that the participants receive less than optimal sleep during the operational period, and showed changes in self-reported fatigue and risk taking. The results are discussed in light of data being collected during a field exercise. Additionally, lessons learned that can be applied to future research are described.

ВЛИЯНИЕ ПЕРЕНЕСЕННОЙ ИНФЕКЦИИ SARS-COV-2 НА МЕНСТРУАЛЬНУЮ ФУНКЦИЮ У ЖЕНЩИН РАННЕГО РЕПРОДУКТИВНОГО ВОЗРАСТА

The pandemic has had a significant impact on the lives of people around the world. Both those who have directly had a coronavirus infection, and those who have been exposed to stress in conditions of social isolation, deteriorating financial well-being and other changes associated with long-term quarantine. Human existence is subject to biological rhythms, adapting the body to changing environmental conditions. One of the most important regulatory roles is played by circadian (daily) rhythms, namely the cycle of sleep and wakefulness. Pineal hormone - melatonin, is involved in the regulation of pigment metabolism, but its main effect is inhibition of the secretion of gonadotropins. In women, the highest level of melatonin is observed during menstruation, the lowest - during ovulation. This hormone plays an important role in the female reproductive system. In turn, SARS-CoV-2 can cause mental disorders by affecting the central nervous system. The most common symptoms and conditions: headaches and dizziness, taste and smell disorders (hyposmia and anosmia), weakness, anxiety, obsessive-compulsive disorders, insomnia, impaired attention and concentration. With prolonged illness, serious disorders of the central nervous system are observed. This study aims to correlate changes in sleep quality and changes in menstrual function in patients who have had SARS-CoV-2 infection.

Relationship between the use of social media and the effects on the sleep cycle among Sri Lankan undergraduate students

Background: University students do not get enough sleep due to many reasons such as mental, health, studies and addicted to social media issues. This research allows to find the impact on sleep cycle of undergraduate students after using social media (Facebook, YouTube and Instagram) Methods and materials: A questionnaire which consist of 10 questions was distributed among undergraduate students from Sri Lanka and 207 students responded. Moreover researches, journals and articles from Google scholar and Pub med are used. IBM SPSS software is used to analyze the gathered data. Results: A comprehensive data analysis shows Facebook is the most used social media. Majority, 108 students use social media for entertainment. 114 students use social media before sleep. Among them 54 students have rated 9 as their quality of sleep. And also 28 students who don’t use social media at all have rated 9 as their quality of sleep. 34 students who do not social media before bedtime have rated 10 as their quality of sleep. Findings give the opportunity to compare the quality of sleep between students who use social media before sleep and who don’t use social media. Conclusion: This project conveys no significant impact on the sleep cycle, using social media before bedtime. According to the survey results students use social media for educational and entertainment purposes. Even though they uses social media before bed, they tend to have a good sleep.

Lipid Therapy for Dyslipidemic Disorders Activates 21st Century Nano Antioxidant Hydrogen as a Potential Anti-COVID-19 Agent: Review

According to the World Health Organization (WHO), coronavirus infection (COVID-19, (COronaVIrus Disease 2019) is an infectious disease caused by the SARS-CoV-2 virus [1]. SARS-CoV-2 virus, Severe Acute Respiratory Syndrome-related coronavirus 2. Initially considered pulmonary - respiratory pathology, then it turned out to be poly-systemic, with multi-inflammation of many other organs, and central nervous system. Multisystem inflammatory syndrome in adults (MIS-A) [2], SARS-CoV-2 liver infection [3]. In pediatrics Multisystem inflammatory syndrome in children (MIS-C) or PMIS-TS (Pediatric MIS temporarily associated with SARS-CoV-2 infection) [4,5], SARS-COV-2/ COVID-19 in children induce Kawasaki-Like Disease [6]. Neurological manifestations [7], recurrence of COVID-19 infection with meningitis without pulmonary involvement [8]. Brain damage in COVID is primarily neurological, as a material signaling pathway of inflammatory COVID-infection of cerebral vessels. This is important, from the release of these patients, from additional stress, suffering, stigmatization in society, their isolation, intimidation, coercion (bullying) with violation and restriction of their rights. Since, concomitantly with inflammatory lesions of many organs, cognitive deficits are a component of the post-acute consequences of COVID-19 (PASC), where the role of the kynurenine pathway is significant with temporary cognitive impairment [9]. The main pathway for the breakdown of tryptophan is an amino acid, without which the synthesis of serotonin is impossible, which controls the cycles of sleep and wakefulness, which is the precursor of the sleep hormone melatonin In patients with COVID-19, an imbalance of T-helpers 1 and 2 leads to a cytokine storm that can contribute to myocardial damage [10]. MIS is conditioned caused by immunocompromising (IC) CHAOS - [C]ardiovascular Compromise: shock; [H]omeostasis; [A]poptosis; [O]rgan Dysfunction; [S]uppression of the Immune System with the development of Systemic inflammatory response syndrome (SIRS) and Multiple Organ Dysfunction Syndrome (MODS) [11,12]. With pronounced multiple and other symptoms: Electro - Ion Membrane Distress Syndrome (Syndrome Maria &amp; Irina Vasilieva) [13,14] with membrane manifestations of electrical storm or electromembrane paralysis; Capillary Leak Syndrome; Microcirculatory-Mitochondrial Distress Syndrom [15,16]. Also described: Overlap mechanisms of transient global amnesia and COVID-19 infection [17]; Hypokalemia-stroke mimic [18]; Differential diagnosis of cacosmia and dysgeusia in COVID-19 pandemic [19].

English translation of the first study reporting cyclical periods of increased respiration and eye and body motility during sleep in infants in 1926, with commentary.

This is the first English translation of the work Periodic phenomena in the sleep in children, published in 1926 in the Journal Novoe v refleksologii i fiziologii nervnoi sistemy (Vol. 2, pp. 338-345) by Maria Denisova and Nicholai Figurin; it is the first study to report data on what is currently termed rapid eye movement (REM) sleep. The authors acquired continuous quantitative respiration data, as well as, eye and body movements during sleep in children for up to 6 hours, and discovered several novel features of sleep cycles in healthy infants from birth to about 1 year of age. First, the study reports cyclical periods of increased respiration and eye and body movements, with rapid ocular movements visible under relaxed eyelids (separation: 0.5-1 mm). These observations suggest atonia of REM sleep. Second, the length of the complete cycle (alternating active and quiet sleep phases or states) is about 50 minutes, an estimate that is consistent with later work. Third, the study identifies infant-specific ordering of sleep states, with the active phase beginning after sleep onset, followed by the quiescence phase. Importantly, these published data on sleep cycles precede all published studies related to the state now termed REM sleep by about 30 years (i.e. publishing in Science and in the Journal of Applied Physiology in the 1950s by Eugene Aserinski and Nathaniel Kleitman). In the historical commentary accompanying this translation, the findings of those later works are carefully compared to the original data on respiration and ocular and body motility cycles during sleep in infants, first reported and published by Denisova and Figurin (1926).