Virtual Reality in Acute and Chronic Pain Medicine: An Updated Review

PURPOSE OF REVIEW

This review critically analyzes the recent literature on virtual reality's (VR) use in acute and chronic pain management, offering insights into its efficacy, applications, and limitations.

RECENT FINDINGS

Recent studies, including meta-analyses and randomized controlled trials, have demonstrated VR's effectiveness in reducing pain intensity in various acute pain scenarios, such as procedural/acute pain and in chronic pain conditions. The role of factors such as immersion and presence in enhancing VR's efficacy has been emphasized. Further benefits have been identified in the use of VR for assessment as well as symptom gathering through conversational avatars. However, studies are limited, and strong conclusions will require further investigation. VR is emerging as a promising non-pharmacological intervention in pain management for acute and chronic pain. However, its long-term efficacy, particularly in chronic pain management, remains an area requiring further research. Key findings highlight that VR programs vary in efficacy depending on the specificity of the origin of pain.

Definition of the Post-COVID syndrome using a symptom-based Post-COVID score in a prospective, multi-center, cross-sectoral cohort of the German National Pandemic Cohort Network (NAPKON)

PURPOSE

The objective examination of the Post-COVID syndrome (PCS) remains difficult due to heterogeneous definitions and clinical phenotypes. The aim of the study was to verify the functionality and correlates of a recently developed PCS score.

METHODS

The PCS score was applied to the prospective, multi-center cross-sectoral cohort (in- and outpatients with SARS-CoV-2 infection) of the "National Pandemic Cohort Network (NAPKON, Germany)". Symptom assessment and patient-reported outcome measure questionnaires were analyzed at 3 and 12 months (3/12MFU) after diagnosis. Scores indicative of PCS severity were compared and correlated to demographic and clinical characteristics as well as quality of life (QoL, EQ-5D-5L).

RESULTS

Six hundred three patients (mean 54.0 years, 60.6% male, 82.0% hospitalized) were included. Among those, 35.7% (215) had no and 64.3% (388) had mild, moderate, or severe PCS. PCS severity groups differed considering sex and pre-existing respiratory diseases. 3MFU PCS worsened with clinical severity of acute infection (p = .011), and number of comorbidities (p = .004). PCS severity was associated with poor QoL at the 3MFU and 12MFU (p < .001).

CONCLUSION

The PCS score correlated with patients' QoL and demonstrated to be instructive for clinical characterization and stratification across health care settings. Further studies should critically address the high prevalence, clinical relevance, and the role of comorbidities.

TRAIL REGISTRATION NUMBER

The cohort is registered at www.

CLINICALTRIALS

gov under NCT04768998.

Associations between Sleep Disturbances, Personality Traits and Self-Regulation in a Sample of Healthy Adults

Background: Scientific evidence and everyday experience show that sleep disturbances and self-regulation as a proxy of stress reactivity are linked. Particular personality traits such as neuroticism, internalizing and externalizing problems are also associated with sleep disturbances. Here, we combined self-regulation and personality traits and associated these variables with subjective sleep disturbances. Methods: A total of 846 adults (mean age: 33.7 years; 78.7% females) completed questionnaires covering sleep disturbances, self-regulation and personality traits. Results: Higher scores for sleep disturbances were associated with higher scores for externalization, internalization, and instability and with lower scores for stability (all trait variables) and with poorer self-regulation (state variable). The regression model showed that higher scores for externalization and internalization (traits), and lower scores for self-regulation (state) predicted higher scores for sleep disturbance. Next, self-regulation had both a direct effect on sleep disturbance, and an indirect effect via personality traits. Conclusions: Sleep disturbances were related to both state (i.e., self-regulation) and trait (e.g., internalization and instability) dimensions. The current data analysis leapfrogs the state-trait dichotomy discussion and reconciles the state-and-trait approach in the prediction of poor sleep, though self-regulation appeared to have both direct and indirect effects on sleep disturbances.

MRS study on the correlation between frontal GABA+/Glx ratio and abnormal cognitive function in medication-naive patients with narcolepsy

OBJECTIVE

To compare the GABA+/Glx (glutamate-glutamine) ratio in the prefrontal lobe under non-rapid eye movement sleep between patients with narcolepsy type 1 (NT1) and normal controls and explore the correlation between this difference and abnormal cognitive function, using synchronous electroencephalography-functional magnetic resonance spectroscopy (EEG-fMRS).

METHODS

MRS measurements of GABA+ and Glx concentrations as well as synchronous EEG data were obtained from 26 medication-naive patients with NT1 and 29 sex- and age-matched healthy community volunteers. Cognition was appraised with the Beijing version of the Montreal Cognitive Assessment, and daytime sleepiness was measured using the Epworth Sleepiness Scale. All subjects recorded a 2-week sleep log as well as an overnight polysomnography within 1 week before MR scanning to understand their sleep habits and determine sleep stages. After PSG, they also underwent multiple sleep latency trials. Patient/control group differences in the individual measurements of GABA+ and Glx and the GABA+/Glx ratio and their relationship with cognition were assessed.

RESULTS

The GABA+/Glx ratio and GABA + levels of patients with narcolepsy were higher than those of the control group (P＜0.0001 and P = 0.0008, respectively). However, there was no significant difference in Glx levels (P = 0.6360). The GABA+/Glx ratio negatively correlated with abnormal cognitive function (r = -0.6710, P = 0.0002). Moreover, GABA + levels were inversely proportional to rapid eye movement sleep latency (REML) in patients with narcolepsy (r = -0.5019, P = 0.0106).

CONCLUSION

The GABA+/Glx ratio in the prefrontal lobe was higher in NT1 patients during N2 sleep than in normal controls, mainly caused by GABA + levels; this ratio was negatively related to abnormal cognitive function. In addition, GABA + levels were inversely proportional to REML.

Depression, anxiety, and insomnia symptoms among Chinese college students: A network analysis across pandemic stages

BACKGROUND

As the stages of the COVID-19 pandemic evolved, the symptoms of depression, anxiety, and insomnia have increasingly manifested among Chinese college students. The aim of this study is to investigate the relationships between these symptoms through network analysis among Chinese college students during COVID-19.

METHOD

A three-wave cross-sectional survey was conducted at 22 colleges in Guangdong Province, involving 381,152 students during three specific time intervals: T1 (baseline, February 3 to 10, 2020), T2 (19 months after baseline, June 10 to 18, 2021), and T3 (37 months after baseline, March 15 to April 22, 2023). Depression (PHQ-9), anxiety (GAD-7), and insomnia (YSIS) were used separately. We analyzed two key network indices: "Expected influence" and "Bridge expected influence". Network stability was assessed through a case-dropping bootstrap program.

RESULT

The effective sample sizes for the three periods were as follows: T1 - 164,101 (103,645 females, 63.2 %), T2 - 86,767 (52,146 females, 60.1 %), and T3 - 130,284 (76,720 females, 58.9 %). Across these three periods, the key central symptoms were "Fatigue" (PHQ4), "Restlessness" (GAD5), "Uncontrollable worrying" (GAD2), "Worry too much" (GAD3) and "Sleep insufficiency" (YSIS6). Notably, "Fatigue" (PHQ4), "Restlessness" (GAD5) and "Irritability" (GAD6) consistently served as bridge symptoms. In the T1 and T2 period, "Motor" (PHQ8) acted as a bridge symptom but weakened in T3.

CONCLUSION

Throughout the three periods, the mental health issues among Chinese college students displayed characteristics of somatization within the depression-anxiety-insomnia comorbidity network. Over time, anxiety symptoms appeared to become more prominent. Consequently, this study highlights the importance of accurately identifying and promptly intervening in these core symptoms of mental health among college students, as these symptoms may evolve across different stages of a pandemic.

Impact of Home-Based Work during the COVID-19 Pandemic on Mental and Physical Health in a German Population-Based Sample

Background: The COVID-19 outbreak necessitated physical distancing, as part of secondary prevention, at a personal and professional level. Working from home (WFH) became increasingly important. In this study, the impact of the COVID-19 pandemic restrictions on physical and mental health is investigated, compared with pre-pandemic data, and with employees who WFH and are on-site. Methods: Data from the German Saxon longitudinal study population were used. Attitudes towards WFH as well as mental and physical health assessments during the COVID-19 pandemic were examined. Comparisons were made with corresponding pre-pandemic scores and between employees WFH and on-site in 2022. Results: In total, 319 participants with equal gender distribution were included. Of those, 86 worked from home stating better organizability of their work, more time for partnership, less stress, and greater work satisfaction. Compared to pre-pandemic data, the D-score, PHQ-4, G-Score, and PHQ-SSS-8 showed a significant increase. No difference in physical or mental health between employees WFH and on-site was observed. Conclusion: In general, COVID-19 restrictions had a negative impact on mental and physical health. Although WFH is well accepted, it did not show significant health benefits.

The Effect of Sleep Deprivation on Brain Fingerprint Stability: A Magnetoencephalography Validation Study

This study examined the stability of the functional connectome (FC) over time using fingerprint analysis in healthy subjects. Additionally, it investigated how a specific stressor, namely sleep deprivation, affects individuals' differentiation. To this aim, 23 healthy young adults underwent magnetoencephalography (MEG) recording at three equally spaced time points within 24 h: 9 a.m., 9 p.m., and 9 a.m. of the following day after a night of sleep deprivation. The findings indicate that the differentiation was stable from morning to evening in all frequency bands, except in the delta band. However, after a night of sleep deprivation, the stability of the FCs was reduced. Consistent with this observation, the reduced differentiation following sleep deprivation was found to be negatively correlated with the effort perceived by participants in completing the cognitive task during sleep deprivation. This correlation suggests that individuals with less stable connectomes following sleep deprivation experienced greater difficulty in performing cognitive tasks, reflecting increased effort.

The effects of radiofrequency electromagnetic fields exposure on human self-reported symptoms: A systematic review of human experimental studies

BACKGROUND

The technological applications of radiofrequency electromagnetic fields (RF-EMF) have been steadily increasing since the 1950s exposing large proportions of the population. The World Health Organization (WHO) is assessing the potential health effects of exposure to RF-EMF.

OBJECTIVES

To systematically assess the effects of exposure to RF-EMF on self-reported non-specific symptoms in human subjects and to assess the accuracy of perceptions of presence or absence of RF-EMF exposure.

METHODS

Eligibility criteria: experimental studies carried out in the general population and in individuals with idiopathic environmental intolerance attributed to EMF (IEI-EMF), in any language.

INFORMATION SOURCES

Medline, Web of Science, PsycInfo, Cochrane Library, Epistemonikos, Embase and EMF portal, searched till April 2022. Risk of Bias (ROB): we used the RoB tool developed by OHAT adapted to the topic of this review.

SYNTHESIS OF RESULTS

we synthesized studies using random effects meta-analysis and sensitivity analyses, where appropriate.

RESULTS

Included studies: 41 studies were included, mostly cross over trials and from Europe, with a total of 2,874 participants.

SYNTHESIS OF RESULTS

considering the primary outcomes, we carried out meta-analyses of 10 exposure-outcomes pairs. All evidence suggested no or small non-significant effects of exposure on symptoms with high (three comparisons), moderate (four comparisons), low (one comparison) and very low (two comparisons) certainty of evidence. The effects (standard mean difference, where positive values indicate presence of symptom being exposed) in the general population for head exposure were (95% confidence intervals) 0.08 (-0.07 to 0.22) for headache, -0.01 (-0.22 to 0.20) for sleeping disturbances and 0.13 (-0.51 to 0.76) for composite symptoms; and for whole-body exposure: 0.09 (-0.35 to 0.54), 0.00 (-0.15 to 0.15) for sleeping disturbances and -0.05 (-0.17 to 0.07) for composite symptoms. For IEI-EMF individuals SMD ranged from -0.19 to 0.11, all of them with confidence intervals crossing the value of zero. Further, the available evidence suggested that study volunteers could not perceive the EMF exposure status better than what is expected by chance and that IEI-EMF individuals could not determine EMF conditions better than the general population.

DISCUSSION

Limitations of evidence: experimental conditions are substantially different from real-life situations in the duration, frequency, distance and position of the exposure. Most studies were conducted in young, healthy volunteers, who might be more resilient to RF-EMF than the general population. The outcomes of interest in this systematic review were symptoms, which are self-reported. The available information did not allow to assess the potential effects of exposures beyond acute exposure and in elderly or in chronically ill people. It cannot be ruled out that a real EMF effect in IEI-EMF groups is masked by a mix with insensitive subjects. However, studies on symptoms reporting and/or field perceptions did not find any evidence that there were particularly vulnerable individuals in the IEI-EMF group, although in open provocation studies, when volunteers were informed about the presence or absence of EMF exposure, such differences were consistently observed.

INTERPRETATION

available evidence suggests that acute RF-EMF below regulatory limits does not cause symptoms and corresponding claims in the everyday life are related to perceived and not to real EMF exposure status.

Attention and executive function impairments in obstructive sleep apnea are associated with decreased sleep spindles

INTRODUCTION

Sleep spindles play a key role in sleep-mediated cognitive processes. Cognitive functions are well-known to be affected in obstructive sleep apnea (OSA). Here, we analyzed attention and executive functions in patients with OSA and investigated the relationship between sleep spindles and cognitive abilities.

METHODS

Sixty patients with OSA (18-65 years, 19 females and 41 males) and a control group (n = 41) including age-and sex-matched healthy individuals were consecutively and prospectively enrolled. All participants had a full-night polysomnography, and sleep spindles were analyzed using a semi-automated program. For the evaluation of short-term memory, attention and executive functions, Stroop test, forward and backward digit span tests were applied to all participants upon awakening following polysomnography.

RESULTS

Scores of forward and backward digit span and Stroop tests were worse in OSA patients in compared to those in controls. Mean density of sleep spindles was decreased in OSA patients than those in controls (p = 0.044). A positive correlation was found between fast sleep spindle frequency and forward digit span (r = 2.222; p = 0.038) and backward digit span test scores (r = 2,157; p = 0.042) in OSA patients. In patients with moderate to severe OSA, sleep spindle density was positively correlated with forward (r = 2.323, p = 0.029) and backward (r = 2.500, p = 0.016) DSTs, and the duration of sleep spindles had positive correlation with backward DST (r = 2.452, p = 0.010).

CONCLUSION

Our findings demonstrated that the disturbances in sleep spindle characteristics in OSA are associated with the cognitive impairments in attention, short-term memory, and executive functions, especially in patients with moderate to severe OSA.

Actigraphic and self-reported characterization of sleep in systemic lupus erythematosus patients

OBJECTIVES

In a cross-sectional study, we explored possible differences in sleep parameters between SLE patients and age- and gender-matched healthy controls through actigraphic and self-reported measures. Furthermore, we aimed to identify possible predictors of such disturbances in the patient cohort.

METHODS

Participants' sociodemographic data and sleep parameters were collected. Sleep parameters were evaluated through the Pittsburgh Sleep Quality Index, the Insomnia Severity Index and 7-day actigraphic monitoring. The 10-item Perceived Stress Scale was used to investigate stress. Disease activity and daily glucocorticoid dose were assessed in SLE patients. Possible predictors of the SLE group were explored through two binomial logistic models. Within the SLE group, possible predictors of sleep parameters were tested estimating multiple linear regression models.

RESULTS

A total of 40 SLE patients and 33 controls were included in the study. The SLE group showed worse sleep maintenance actigraphic parameters (i.e. sleep efficiency and wake after sleep onset), higher total sleep time and higher perceived stress. Within the SLE cohort, the daily glucocorticoids dose was associated with an impairment in sleep maintenance despite no reduction in sleep duration, typical of normal sleep duration insomnia, whereas perceived stress was associated with short sleep duration insomnia.

CONCLUSION

Compared with healthy controls, SLE patients showed worse sleep quality and greater perceived stress severity. As glucocorticoids and perceived stress are associated with different types of insomnia in these patients, a multidimensional approach to both sleep characterization and therapy might be preferred.

Sex Differences in Neuromuscular Aging: The Role of Sex Hormones

Males and females experience different trajectories of neuromuscular function across the lifespan, with females demonstrating accelerated deconditioning in later life. We hypothesize that the menopause is a critical period in the female lifespan, during which the dramatic reduction in sex hormone concentrations negatively impacts synaptic input to the motoneuron pool, as well as motor unit discharge properties.

Environmental enrichment reverses proulcerogenic action of social isolation on the gastric mucosa and positively influences pain sensitivity and work capacity

The aim of the study was to investigate the effects of rat housing conditions-standard conditions, social isolation, environmental enrichment-and the subsequent reversal of these conditions on the vulnerability of the gastric mucosa to ulcerogenic stimuli, somatic pain sensitivity, and treadmill work capacity. Rats, aged 30 days, were placed in standard conditions (SC), social isolation (Is), and environmental enrichment (EE) for 4 weeks. Then half of each group underwent a reversal of housing conditions: SC rats were moved to Is, Is rats were placed in EE, EE rats were moved to Is, for 2 weeks. The other half served as a control with no change in their initial housing. Two weeks after the reversal, vulnerability of the gastric mucosa to ulcerogenic action of indomethacin (IM, 35 mg/kg, sc), somatic pain sensitivity (hot plate test), and work capacity (measured by the running distance on a treadmill) were assessed in control and reversed groups. Social isolation induced a proulcerogenic effect, increasing IM-induced gastric erosions, which was effectively reversed when rats were transferred to an environmental enrichment. Conversely, transferring rats from an environmental enrichment to social isolation exacerbated ulcerogenic action of IM. Somatic pain sensitivity and treadmill work capacity were also influenced by housing conditions, with environmental enrichment showing positive effects. The present findings show that social isolation of rats induces a proulcerogenic effect. Environmental enrichment reverses proulcerogenic action of social isolation on the gastric mucosa and increases resilience to pain stimuli and treadmill work capacity.

Influencing dreams through sensory stimulation: A systematic review

Sleep is typically considered a state of disconnection from the environment, yet instances of external sensory stimuli influencing dreams have been reported for centuries. Explaining this phenomenon could provide valuable insight into dreams' generative and functional mechanisms, the factors that promote sleep continuity, and the processes that underlie conscious awareness. Moreover, harnessing sensory stimuli for dream engineering could benefit individuals suffering from dream-related alterations. This PRISMA-compliant systematic review assessed the current evidence concerning the influence of sensory stimulation on sleep mentation. We included 51 publications, of which 21 focused on auditory stimulation, ten on somatosensory stimulation, eight on olfactory stimulation, four on visual stimulation, two on vestibular stimulation, and one on multimodal stimulation. Furthermore, nine references explored conditioned associative stimulation: six focused on targeted memory reactivation protocols and three on targeted lucid reactivation protocols. The reported frequency of stimulus-dependent dream changes across studies ranged from 0 to ∼80%, likely reflecting a considerable heterogeneity of definitions and methodological approaches. Our findings highlight a lack of comprehensive understanding of the mechanisms, functions, and neurophysiological correlates of stimulus-dependent dream changes. We suggest that a paradigm shift is required for meaningful progress in this field.

Sleep spindles as neurophysiological biomarkers of schizophrenia

Schizophrenia (SCZ) is a complex psychiatric disorder characterized by a wide range of clinical symptoms, including disrupted sleep. In recent years, there has been growing interest in assessing alterations in sleep parameters in patients with SCZ. Sleep spindles are brief (0.5-2 s) bursts of 12- to 16-Hz rhythmic electroencephalogram (EEG) oscillatory activity occurring during non-rapid eye movement (NREM) sleep. Spindles have been implicated in several critical brain functions, including learning, memory and plasticity, and are thought to reflect the integrity of underlying thalamocortical circuits. This review aims to provide an overview of the current research investigating sleep spindles in SCZ. After briefly describing the neurophysiological features of sleep spindles, I will discuss alterations in spindle characteristics observed in SCZ, their associations with the clinical symptomatology of these patients and their putative underlying neuronal and molecular mechanisms. I will then discuss the utility of sleep spindle measures as predictors of treatment response and disease progression. Finally, I will highlight future directions for research in this emerging field, including the prospect of utilizing sleep spindles as neurophysiological biomarkers of SCZ.

Daily worry, rumination, and sleep in late life

OBJECTIVE

Perseverative thinking (e.g., worry/rumination) is a common response to stress, and can be detrimental to well-being. Sleep may represent an important mechanism by which perseverative thinking is disrupted or amplified from day to day. This study examined the associations between older adults' everyday worry, rumination, and sleep.

METHODS

Older adults (N = 270) aged 65-89 completed a baseline interview and morning and evening assessments each day for 5-6 days. Every morning, they indicated their worry toward the day and their sleep duration and disturbances the prior night. Every evening, they rated worry and rumination experienced that day.

RESULTS

Multilevel models showed that perseverative thinking predicted worse sleep (i.e., fewer hours of sleep) at the between-person level (B = -0.29, p = .004) but better sleep (i.e., fewer sleep disturbances) at the within-person level (Bs < -0.18, ps < .003). At the within-person level, more hours of sleep (B = -0.06, p = .04) and fewer sleep disturbances (B = 0.10, p < .001) predicted less worry the next morning. Prior night's worry predicted greater next morning's worry, but this association was significant only when older adults reported fewer-than-usual hours of sleep (B = 0.24, p < .001), not when they reported more-than-usual hours of sleep (B = 0.04, p = .61).

CONCLUSION

Findings suggest that worry and rumination are intimately linked with sleep and highlight the protective role that better sleep may play in reducing older adults' everyday perseverative thinking.

A growth chart of brain function from infancy to adolescence based on EEG

BACKGROUND

In children, objective, quantitative tools that determine functional neurodevelopment are scarce and rarely scalable for clinical use. Direct recordings of cortical activity using routinely acquired electroencephalography (EEG) offer reliable measures of brain function.

METHODS

We developed and validated a measure of functional brain age (FBA) using a residual neural network-based interpretation of the paediatric EEG. In this cross-sectional study, we included 1056 children with typical development ranging in age from 1 month to 18 years. We analysed a 10- to 15-min segment of 18-channel EEG recorded during light sleep (N1 and N2 states).

FINDINGS

The FBA had a weighted mean absolute error (wMAE) of 0.85 years (95% CI: 0.69-1.02; n = 1056). A two-channel version of the FBA had a wMAE of 1.51 years (95% CI: 1.30-1.73; n = 1056) and was validated on an independent set of EEG recordings (wMAE = 2.27 years, 95% CI: 1.90-2.65; n = 723). Group-level maturational delays were also detected in a small cohort of children with Trisomy 21 (Cohen's d = 0.36, p = 0.028).

INTERPRETATION

A FBA, based on EEG, is an accurate, practical and scalable automated tool to track brain function maturation throughout childhood with accuracy comparable to widely used physical growth charts.

FUNDING

This research was supported by the National Health and Medical Research Council, Australia, Helsinki University Diagnostic Center Research Funds, Finnish Academy, Finnish Paediatric Foundation, and Sigrid Juselius Foundation.

Linking activity dyshomeostasis and sleep disturbances in Alzheimer disease

The presymptomatic phase of Alzheimer disease (AD) starts with the deposition of amyloid-β in the cortex and begins a decade or more before the emergence of cognitive decline. The trajectory towards dementia and neurodegeneration is shaped by the pathological load and the resilience of neural circuits to the effects of this pathology. In this Perspective, I focus on recent advances that have uncovered the vulnerability of neural circuits at early stages of AD to hyperexcitability, particularly when the brain is in a low-arousal states (such as sleep and anaesthesia). Notably, this hyperexcitability manifests before overt symptoms such as sleep and memory deficits. Using the principles of control theory, I analyse the bidirectional relationship between homeostasis of neuronal activity and sleep and propose that impaired activity homeostasis during sleep leads to hyperexcitability and subsequent sleep disturbances, whereas sleep disturbances mitigate hyperexcitability via negative feedback. Understanding the interplay among activity homeostasis, neuronal excitability and sleep is crucial for elucidating the mechanisms of vulnerability to and resilience against AD pathology and for identifying new therapeutic avenues.

Overnight neuronal plasticity and adaptation to emotional distress

Expressions such as 'sleep on it' refer to the resolution of distressing experiences across a night of sound sleep. Sleep is an active state during which the brain reorganizes the synaptic connections that form memories. This Perspective proposes a model of how sleep modifies emotional memory traces. Sleep-dependent reorganization occurs through neurophysiological events in neurochemical contexts that determine the fates of synapses to grow, to survive or to be pruned. We discuss how low levels of acetylcholine during non-rapid eye movement sleep and low levels of noradrenaline during rapid eye movement sleep provide a unique window of opportunity for plasticity in neuronal representations of emotional memories that resolves the associated distress. We integrate sleep-facilitated adaptation over three levels: experience and behaviour, neuronal circuits, and synaptic events. The model generates testable hypotheses for how failed sleep-dependent adaptation to emotional distress is key to mental disorders, notably disorders of anxiety, depression and post-traumatic stress with the common aetiology of insomnia.

Coupled sleep rhythms for memory consolidation

How do passing moments turn into lasting memories? Sheltered from external tasks and distractions, sleep constitutes an optimal state for the brain to reprocess and consolidate previous experiences. Recent work suggests that consolidation is governed by the intricate interaction of slow oscillations (SOs), spindles, and ripples - electrophysiological sleep rhythms that orchestrate neuronal processing and communication within and across memory circuits. This review describes how sequential SO-spindle-ripple coupling provides a temporally and spatially fine-tuned mechanism to selectively strengthen target memories across hippocampal and cortical networks. Coupled sleep rhythms might be harnessed not only to enhance overnight memory retention, but also to combat memory decline associated with healthy ageing and neurodegenerative diseases.

The assessment of emotion reactivity: The Italian validation of the Perth Emotional Reactivity Scale-Short Form (PERS-S)

Emotion reactivity refers to the activation, intensity and duration of emotional responses to internal or external stimuli. It can be differentiated from emotion regulation since the former is the very first response to an emotional trigger, and the latter can be defined as a tool for maintaining one's arousal in a window of tolerance. Since, to date, there are no Italian self-report measures able to evaluate individuals' emotional reactivity, this study aimed to contribute to the Italian validation of the Perth Emotional Reactivity Scale-Short Form (PERS-S). The PERS-S is an 18-item self-report measure answered on a 5-point Likert scale that generates six subscale scores and two composite scores, with higher scores indicating higher levels of reactivity. Data from 768 individuals showed that the PERS-S had good to excellent goodness of fit. The internal consistency was high, with an overall reliability coefficient (Cronbach's α) of .87 and .86 for the negative and positive general scales, respectively. The PERS-S also demonstrated appropriate convergent validity, showing significant correlations with conceptually related measures, and acceptable divergent validity, showing minimal correlations with unrelated constructs. Finally, we evaluated the Test-Retest Reliability by administering the PERS-S to the same sample twice, with a 2-week interval. The significant correlations between the two PERS-S administrations suggest temporal stability. The Italian version of the PERS-S will enrich the repertoire of self-report measures for investigating the development and risk factors of mental health disorders and may have practical applications in clinical settings.

Managing Circadian Disruption due to Hospitalization: A Pilot Randomized Controlled Trial of the CircadianCare Inpatient Management System

The objective of the present study was to test the effects of an inpatient management system (CircadianCare) aimed at limiting the negative impact of hospitalization on sleep by enhancing circadian rhythmicity. Fifty inpatients were randomized to either CircadianCare (n = 25; 18 males, 62.4 ± 1.9 years) or standard of care (n = 25; 14 males, 64.5 ± 2.3 years). On admission, all underwent a full sleep-wake evaluation; they then completed daily sleep diaries and wore an actigraph for the whole length of hospitalization. On days 1 (T0), 7 (T1), and 14 (T2, if still hospitalized), salivary melatonin for dim light melatonin onset (DLMO) and 24-h skin temperature were recorded. In addition, environmental noise, temperature, and illuminance were monitored. Patients in the CircadianCare arm followed 1 of 3 schedules for light/dark, meal, and physical activity timings, based on their diurnal preference/habits. They wore short-wavelength-enriched light-emitting glasses for 45 min after awakening and short-wavelength light filter shades from 18:00 h until sleep onset. While the first, primary registered outcome (reduced sleep-onset latency on actigraphy or diary) was not met, based on sleep diaries, there was a trend (0.05 < p < 0.1) toward an advance in bedtime for CircadianCare compared to standard of care patients between T0 and T1. Similarly, DLMO time significantly advanced in the small group of patients for whom it could be computed on both occasions, with untreated ones starting from earlier baseline values. Patients sleeping near the window had significantly higher sleep efficiency, regardless of treatment arm. As noise fluctuation increased, so did the number of night awakenings, regardless of treatment arm. In conclusion, the CircadianCare management system showed positive results in terms of advancing sleep timing and the circadian rhythm of melatonin. Furthermore, our study identified a combination of environmental noise and lighting indices, which could be easily modulated to prevent hospitalization-related insomnia.

Lifestyle habits, health indicators and sociodemographic factors associated with health-related quality of life and self-esteem in adolescents

BACKGROUND

Mental health is defined as a state of emotional, psychological, and social well-being, and has been shown to be positively associated with self-esteem and quality of life. It is important to note that mental health is dynamic and influenced by a wide range of social, biological, and behavioral factors. Therefore, the aim this study was to describe the health-related quality of life and self-esteem in adolescents, examining their relationship with various health indicators, lifestyle habits, and sociodemographic variables.

METHOD

A cross-sectional study was conducted with a representative sample of 761 students (14.51 ± 1.63 years). Health-related quality of life, self-esteem, satisfaction with body image, adherence to the Mediterranean diet, physical activity practice, hours of nightly sleep, maximum oxygen consumption, body mass index, academic performance, and various sociodemographic factors of all participants were analyzed.

RESULTS

Regression analysis showed that body satisfaction and academic performance were associated of both health-related quality of life and self-esteem. Additionally, physical activity, age, and favourable settings for physical activity engagement were also found to be related to health-related quality of life, whilst adherence to the Mediterranean diet, hours of nightly sleep, maximum oxygen consumption and socioeconomic status were associated with self-esteem.

CONCLUSIONS

Given the associations found between health-related quality of life and self-esteem with lifestyle habits and sociodemographic indicators, there is an urgent need to develop interdisciplinary and cross-cutting promotion strategies to improve the mental health of adolescents.

Nurses quality of life, sleep disturbance, and intention to leave critical care units: A cross-sectional moderated mediation analysis

OBJECTIVES

This study aims to explore the complex relationships between personal and demographic factors, intermediary factors such as quality of life (depression, anxiety, stress, burnout), and the mediating impact of sleep disturbance on nurses' intention to leave critical care units.

DESIGN

Cross-sectional quantitative survey.

SETTING

Data were collected from registered nurses at a major university hospital in southern Italy. Seven inpatient critical care units were sampled.

MAIN OUTCOME MEASURES

Intention to leave critical care units.

RESULTS

We included 160 participants recruited over five weeks in May and June 2023. The data showed that most were female, married, and possessed a bachelor's degree in nursing. The mean quality of life score was moderate, while stress, anxiety, and burnout were mild. A significant percentage of nurses reported poor sleep quality. Logistic regression indicates that service length did not significantly impact the intention to leave. The structural equation model showed that stress positively correlated with emotional exhaustion, whereas job quality was negatively associated with emotional exhaustion and the intention to leave. Sleep disturbance did not explain the relationship between stress and emotional fatigue; however, the results revealed that male gender moderated sleep mediation.

CONCLUSIONS

This study investigated factors influencing intention to leave among critical care unit nurses. The results suggest that the role of sleep disturbance should always be considered when assessing the issue. In this chain of causes, sleep disturbance explains the relationship between stress and emotional exhaustion. Furthermore, the strength of this mediation was influenced by gender, particularly by the male gender.

IMPLICATIONS FOR CLINICAL PRACTICE

Stress and emotional exhaustion significantly impact nurses' working quality of life, particularly when sleep quality is taken into account. This leads to a higher intention to leave critical care units. To reduce this tendency, healthcare managers could implement specific evidence-based interventions to promote a good climate of work, which would positively affect stress, emotional exhaustion and sleep disturbance. The likelihood of intention to leave decreased with achieving personal self-fulfilment among nurses.

Cortical hyperarousal in individuals with frequent nightmares

Nightmares are common among the general population and psychiatric patients and have been associated with signs of nocturnal arousal such as increased heart rate or increased high-frequency electroencephalographic (EEG) activity. However, it is still unclear, whether these characteristics are more of a trait occurring in people with frequent nightmares or rather indicators of the nightmare state. We compared participants with frequent nightmares (NM group; n = 30) and healthy controls (controls; n = 27) who spent 4 nights in the sleep laboratory over the course of 8 weeks. The NM group received six sessions of imagery rehearsal therapy (IRT), the 'gold standard' of cognitive-behavioural therapy for nightmares, between the second and the third night. Sleep architecture and spectral power were compared between groups, and between nights of nightmare occurrence and nights without nightmare occurrence in the NM group. Additionally, changes before and after therapy were recorded. The NM group showed increased beta (16.25-31 Hz) and low gamma (31.25-35 Hz) power during the entire night compared to the controls, but not when comparing nights of nightmare occurrence to those without. Moreover, low gamma activity in rapid eye movement sleep was reduced after therapy in the NM group. Our findings indicate, cortical hyperarousal is more of a trait in people with frequent nightmares within a network of other symptoms, but also malleable by therapy. This is not only a new finding for IRT but could also lead to improved treatment options in the future that directly target high-frequency EEG activity.

Exploring exercise, physical wellbeing and the role of physiotherapy: perspectives from people with narcolepsy

Narcolepsy is associated with reduced quality of life and physical performance. The study aimed to explore the attitudes of people with Type 1 narcolepsy towards exercise and physical activity, their physical wellbeing, and the potential role of physiotherapy. Semi-structured interviews were conducted with 22 people with narcolepsy attending a dedicated outpatient narcolepsy clinic located in Dublin, Ireland. Transcripts were iteratively coded; a thematic analysis was undertaken, and key themes were identified. Four themes were identified: 'Barriers and Facilitators to Exercising', 'Social Concerns', 'Health Concerns' and 'Suggestions for the Role of Physiotherapy'. Future research should explore the potential role of exercise to help manage narcolepsy-related symptoms in this population.

Sleep duration trajectories and cognition in early childhood: A systematic review

Sleep is dynamic in childhood and studies have shown the relationship between sleep and cognition in children. As the human brain is the most plastic during childhood, the study of longitudinal sleep patterns and neurocognition is an important research area. We aimed to systematically review studies that investigated sleep duration trajectories and cognition in typically-developing children. We searched four databases for articles published between 2003 to October 2023. We included observation studies of children with sleep duration trajectories as a predictor and outcomes related to cognition, memory, language, developmental milestones, intelligence or executive function. We excluded studies where children had atypical development or completed the sleep and neurocognitive assessments after six and 12 years of age respectively. Out of 752 articles identified, 511 were screened and 23 full texts were assessed. The selected studies included three single trajectory and four multiple group trajectories studies. We found associations between both types of trajectories and cognitive development. Overall, children with longer sleep trajectories or more mature sleep pattern with rapid decrease in sleep duration, had better performance scores in developmental assessment tools, and intelligence tests. Findings for language and executive functioning were mixed, whereby some studies found associations and others did not.

Emergent effects of synaptic connectivity on the dynamics of global and local slow waves in a large-scale thalamocortical network model of the human brain

Slow-wave sleep (SWS), characterized by slow oscillations (SO, <1Hz) of alternating active and silent states in the thalamocortical network, is a primary brain state during Non-Rapid Eye Movement (NREM) sleep. In the last two decades, the traditional view of SWS as a global and uniform whole-brain state has been challenged by a growing body of evidence indicating that sleep oscillations can be local and can coexist with wake-like activity. However, the understanding of how global and local SO emerges from micro-scale neuron dynamics and network connectivity remains unclear. We developed a multi-scale, biophysically realistic human whole-brain thalamocortical network model capable of transitioning between the awake state and slow-wave sleep, and we investigated the role of connectivity in the spatio-temporal dynamics of sleep SO. We found that the overall strength and a relative balance between long and short-range synaptic connections determined the network state. Models with relatively weaker long-range connectivity resulted in mixed states of global and local slow waves. Increase of synaptic strength led to more synchronized global SO. These results were compared to human data to validate probable models of biophysically realistic slow waves. The model producing mixed states provided the best match to the spatial coherence profiles obtained in the human subjects. These findings shed light on how the spatio-temporal properties of SO emerge from local and global cortical connectivity and provide a framework for further exploring the mechanisms and functions of SWS in health and disease.

Induction of excitatory brain state governs plastic functional changes in visual cortical topology

Adult visual plasticity underlying local remodeling of the cortical circuitry in vivo appears to be associated with a spatiotemporal pattern of strongly increased spontaneous and evoked activity of populations of cells. Here we review and discuss pioneering work by us and others about principles of plasticity in the adult visual cortex, starting with our study which showed that a confined lesion in the cat retina causes increased excitability in the affected region in the primary visual cortex accompanied by fine-tuned restructuring of neuronal function. The underlying remodeling processes was further visualized with voltage-sensitive dye (VSD) imaging that allowed a direct tracking of retinal lesion-induced reorganization across horizontal cortical circuitries. Nowadays, application of noninvasive stimulation methods pursues the idea further of increased cortical excitability along with decreased inhibition as key factors for the induction of adult cortical plasticity. We used high-frequency transcranial magnetic stimulation (TMS), for the first time in combination with VSD optical imaging, and provided evidence that TMS-amplified excitability across large pools of neurons forms the basis for noninvasively targeting reorganization of orientation maps in the visual cortex. Our review has been compiled on the basis of these four own studies, which we discuss in the context of historical developments in the field of visual cortical plasticity and the current state of the literature. Overall, we suggest markers of LTP-like cortical changes at mesoscopic population level as a main driving force for the induction of visual plasticity in the adult. Elevations in excitability that predispose towards cortical plasticity are most likely a common property of all cortical modalities. Thus, interventions that increase cortical excitability are a promising starting point to drive perceptual and potentially motor learning in therapeutic applications.

Embracing sleep-onset complexity

Sleep is crucial for many vital functions and has been extensively studied. By contrast, the sleep-onset period (SOP), often portrayed as a mere prelude to sleep, has been largely overlooked and remains poorly characterized. Recent findings, however, have reignited interest in this transitional period and have shed light on its neural mechanisms, cognitive dynamics, and clinical implications. This review synthesizes the existing knowledge about the SOP in humans. We first examine the current definition of the SOP and its limits, and consider the dynamic and complex electrophysiological changes that accompany the descent to sleep. We then describe the interplay between internal and external processing during the wake-to-sleep transition. Finally, we discuss the putative cognitive benefits of the SOP and identify novel directions to better diagnose sleep-onset disorders.

Bedtime to the brain: how infants' sleep behaviours intertwine with non-rapid eye movement sleep electroencephalography features

Adequate sleep is critical for development and facilitates the maturation of the neurophysiological circuitries at the basis of cognitive and behavioural function. Observational research has associated early life sleep problems with worse later cognitive, psychosocial, and somatic health outcomes. Yet, the extent to which day-to-day sleep behaviours (e.g., duration, regularity) in early life relate to non-rapid eye movement (NREM) neurophysiology-acutely and the long-term-remains to be studied. We measured sleep behaviours in 32 healthy 6-month-olds assessed with actimetry and neurophysiology with high-density electroencephalography (EEG) to investigate the association between NREM sleep and habitual sleep behaviours. Our study revealed four findings: first, daytime sleep behaviours are related to EEG slow-wave activity (SWA). Second, night-time movement and awakenings from sleep are connected with spindle density. Third, habitual sleep timing is linked to neurophysiological connectivity quantified as delta coherence. And lastly, delta coherence at 6 months predicts night-time sleep duration at 12 months. These novel findings widen our understanding that infants' sleep behaviours are closely intertwined with three particular levels of neurophysiology: sleep pressure (determined by SWA), the maturation of the thalamocortical system (spindles), and the maturation of cortical connectivity (coherence). The crucial next step is to extend this concept to clinical groups to objectively characterise infants' sleep behaviours 'at risk' that foster later neurodevelopmental problems.

Pre-existing sleep problems as a predictor of post-acute sequelae of COVID-19

Several months after COVID-19 many individuals still report persisting symptoms, the so-called 'post-COVID-19 syndrome'. An immunological dysfunction is one of the main pathophysiological hypotheses. As sleep is central to the functioning of the immune system, we investigated whether self-reported pre-existing sleep disturbance might be an independent risk factor for the development of post-COVID-19 syndrome. A total of 11,710 participants of a cross-sectional survey (all tested positive for severe acute respiratory syndrome coronavirus-2) were classified into probable post-COVID-19 syndrome, an intermediate group, and unaffected participants at an average of 8.5 months after infection. The case definition was based on newly occurring symptoms of at least moderate severity and ≥20% reduction in health status and/or working capacity. Unadjusted and adjusted odds ratios were calculated to investigate the association between pre-existing sleep disturbances and subsequent development of post-COVID-19 syndrome while controlling for a variety of demographic, lifestyle, and health factors. Pre-existing sleep disturbances were found to be an independent predictor of subsequent probable post-COVID-19 syndrome (adjusted odds ratio 2.7, 95% confidence interval 2.27-3.24). Sleep disturbances as part of the post-COVID-19 syndrome were reported by more than half of the participants and appeared to be a new symptom and to occur independent of a mood disorder in most cases. Recognition of disturbed sleep as an important risk factor for post-COVID-19 syndrome should promote improved clinical management of sleep disorders in the context of COVID-19. Further, it may stimulate further research on the effect of improving sleep on the prognosis of COVID-19 long-term sequelae and other post-viral conditions.

Parasomnias manifest different phenotypes of sleep-related behaviors in age and sex groups. A YouTube-based video research highlighting the age slope of sleepwalking

STUDY OBJECTIVE

Finding typical patterns - phenotypes - of sleep behaviors characterizing parasomnias in different age and sex groups.

METHODS

We analyzed YouTube videos on sleep-related behaviors likely representing parasomnias. We applied the search terms "sleepwalking", "somnambulism", "sleep eating", "sleep sex", "sleep talking", and "aggression in sleep" in six languages. We classified those persons shown on the videos into estimated biological sex and age (child, adult, elderly) groups. We scored the activity types by a self-made scale and applied binary logistic regression to analyze the association between sleep behaviors versus sex and age groups by the STATA package, providing a 95% confidence interval and the probability of statistical significance.

RESULTS

224 videos (102 women, 68 children, 16 adults, and 40 elderly people) were scored. Elderly people had significantly (P < 0.012) lower odds of sleepwalking compared to adults and children. Adult females performed complex manual activities during sleepwalking more often than males (P < 0.012). Elderly males had 40-fold odds compared to adults and children, to perform aggressive movements and 70-fold odds of complex movements in bed, compared to adults. Elderly people presented emotional behaviors less frequently than adults (P < 0.004), and females showed them twice as often as males. Adults sleep-talked full sentences more often than children and elderly people (P < 0.001).

CONCLUSION

Our results support the existence of age- and sex-specific parasomnia phenotypes, denoting possible safety measures. The remarkably low odds of sleepwalking in the elderly highlight the possibility of different pathomechanisms in higher age groups compared to children.

BRIEF SUMMARY AND STUDY IMPACT

Parasomnias present highly variable clinical forms and often cause injuries. Identifying typical phenotypes may help risk management and imply theoretical conclusions. Our study supports the existence of age-specific parasomnia phenotypes. We found that adult women have a high risk of performing dangerous activities during sleep, and elderly males often move violently in bed, likely representing dream enactment behaviors. Elderly people of both sexes have low odds of sleep ambulation- likely representing somnambulism; compared to adults and children, constituting a descending "age slope" of somnambulism that might reflect different underlying pathomechanisms in children versus adults and the elderly.

Sleep deprivation attenuates neural responses to outcomes from risky decision-making

Sleep loss impacts a broad range of brain and cognitive functions. However, how sleep deprivation affects risky decision-making remains inconclusive. This study used functional MRI to examine the impact of one night of total sleep deprivation (TSD) on risky decision-making behavior and the underlying brain responses in healthy adults. In this study, we analyzed data from N = 56 participants in a strictly controlled 5-day and 4-night in-laboratory study using a modified Balloon Analogue Risk Task. Participants completed two scan sessions in counter-balanced order, including one scan during rested wakefulness (RW) and another scan after one night of TSD. Results showed no differences in participants' risk-taking propensity and risk-induced activation between RW and TSD. However, participants showed significantly reduced neural activity in the anterior cingulate cortex and bilateral insula for loss outcomes, and in bilateral putamen for win outcomes during TSD compared with RW. Moreover, risk-induced activation in the insula negatively correlated with participants' risk-taking propensity during RW, while no such correlations were observed after TSD. These findings suggest that sleep loss may impact risky decision-making by attenuating neural responses to decision outcomes and impairing brain-behavior associations.

An Examination of Sleep as a Mediator of the Relationship between Childhood Adversity and Depression in Hispanic and Non-Hispanic Young Adults

The current study integrates previous research on adverse childhood experiences (ACEs) and long-term health outcomes to examine associations between ACEs, sleep duration, and depression in a diverse, mostly healthy, sample of young adults. We examine whether sleep duration mediates the association between ACEs and depression among young adults, and whether ethnicity may moderate observed relationships between ACEs, sleep duration and depression. Data were collected from 518 young adults (66.8% female, Mage=19.79 years, SDage=3.43 years) enrolled in undergraduate Psychology courses at a large Southwestern university. Participants primarily reported their racial/ethnic background as Non-Hispanic White (60.6%) and Hispanic/Latino (25.1%). Participants self-reported their ACEs exposure, sleep characteristics, and depressive symptoms. In addition to calculating overall exposure to ACEs, scores for the specific dimensions of adversity were also calculated (Abuse, Neglect, Exposure to Violence). Results supported a mediation model whereby higher reports of ACEs were associated with depressive symptoms both directly and through sleep duration. Results were not moderated by ethnicity. Findings provide support for sleep duration as one potential pathway through which ACEs may be associated with depressive symptoms in young adulthood, and suggest that this pathway is similar in Hispanic and non-Hispanic young adults.

Disentangling neuroplasticity mechanisms in post-stroke language recovery

A major objective in post-stroke aphasia research is to gain a deeper understanding of neuroplastic mechanisms that drive language recovery, with the ultimate goal of enhancing treatment outcomes. Subsequent to recent advances in neuroimaging techniques, we now have the ability to examine more closely how neural activity patterns change after a stroke. However, the way these neural activity changes relate to language impairments and language recovery is still debated. The aim of this review is to provide a theoretical framework to better investigate and interpret neuroplasticity mechanisms underlying language recovery in post-stroke aphasia. We detail two sets of neuroplasticity mechanisms observed at the synaptic level that may explain functional neuroimaging findings in post-stroke aphasia recovery at the network level: feedback-based homeostatic plasticity and associative Hebbian plasticity. In conjunction with these plasticity mechanisms, higher-order cognitive control processes dynamically modulate neural activity in other regions to meet communication demands, despite reduced neural resources. This work provides a network-level neurobiological framework for understanding neural changes observed in post-stroke aphasia and can be used to define guidelines for personalized treatment development.

Sleepiness and the transition from wakefulness to sleep

The transition from wakefulness to sleep is a progressive process that is reflected in the gradual loss of responsiveness, an alteration of cognitive functions, and a drastic shift in brain dynamics. These changes do not occur all at once. The sleep onset period (SOP) refers here to this period of transition between wakefulness and sleep. For example, although transitions of brain activity at sleep onset can occur within seconds in a given brain region, these changes occur at different time points across the brain, resulting in a SOP that can last several minutes. Likewise, the transition to sleep impacts cognitive and behavioral levels in a graded and staged fashion. It is often accompanied and preceded by a sensation of drowsiness and the subjective feeling of a need for sleep, also associated with specific physiological and behavioral signatures. To better characterize fluctuations in vigilance and the SOP, a multidimensional approach is thus warranted. Such a multidimensional approach could mitigate important limitations in the current classification of sleep, leading ultimately to better diagnoses and treatments of individuals with sleep and/or vigilance disorders. These insights could also be translated in real-life settings to either facilitate sleep onset in individuals with sleep difficulties or, on the contrary, prevent or control inappropriate sleep onsets.

From physiological awakening to pathological sleep inertia: Neurophysiological and behavioural characteristics of the sleep-to-wake transition

Sleep inertia refers to the transient physiological state of hypoarousal upon awakening, associated with various degrees of impaired neurobehavioral performance, confusion, a desire to return to sleep and often a negative emotional state. Scalp and intracranial electro-encephalography as well as functional imaging studies have provided evidence that the sleep inertia phenomenon is underpinned by an heterogenous cerebral state mixing local sleep and local wake patterns of activity, at the neuronal and network levels. Sleep inertia is modulated by homeostasis and circadian processes, sleep stage upon awakening, and individual factors; this translates into a huge variability in its intensity even under physiological conditions. In sleep disorders, especially in hypersomnolence disorders such as idiopathic hypersomnia, sleep inertia may be a daily, serious and long-lasting symptom leading to severe impairment. To date, few tools have been developed to assess sleep inertia in clinical practice. They include mainly questionnaires and behavioral tests such as the psychomotor vigilance task. Only one neurophysiological protocol has been evaluated in hypersomnia, the forced awakening test which is based on an event-related potentials paradigm upon awakening. This contrasts with the major functional consequences of sleep inertia and its potentially dangerous consequences in subjects required to perform safety-critical tasks soon after awakening. There is a great need to identify reproducible biomarkers correlated with sleep inertia-associated cognitive and behavioral impairment. These biomarkers will aim at better understanding and measuring sleep inertia in physiological and pathological conditions, as well as objectively evaluating wake-promoting treatments or non-pharmacological countermeasures to reduce this phenomenon.

The role of the GABAergic system on insomnia

Sleep is an essential activity for the survival of mammals. Good sleep quality helps promote the performance of daily functions. In contrast, insufficient sleep reduces the efficiency of daily activities, causes various chronic diseases like Alzheimer's disease, and increases the risk of having accidents. The GABAergic system is the primary inhibitory neurotransmitter system in the central nervous system. It transits the gamma-aminobutyric acid (GABA) neurotransmitter via GABAA and GABAB receptors to counterbalance excitatory neurotransmitters, such as glutamate, noradrenaline, serotonin, acetylcholine, orexin, and dopamine, which release and increase arousal activities during sleep. Several studies emphasized that dysfunction of the GABAergic system is related to insomnia, the most prevalent sleep-related disorder. The GABAergic system comprises the GABA neurotransmitter, GABA receptors, GABA synthesis, and degradation. Many studies have demonstrated that GABA levels correlate with sleep quality, suggesting that modulating the GABAergic system may be a promising therapeutic approach for insomnia. In this article, we highlight the significance of sleep, the classification and pathology of insomnia, and the impact of the GABAergic system changes on sleep. In addition, we also review the medications that target the GABAergic systems for insomnia, including benzodiazepines (BZDs), non-BZDs, barbiturates, GABA supplements, and Chinese herbal medicines.

Associations of Anxiety, Insomnia, and Physical Activity during the COVID-19 Pandemic

PURPOSE

Anxiety, insomnia, and physical activity (PA) are interrelated, but the bi-directional relationships between these three variables are not well understood. Less is known of these relationships in settings of disrupted daily activities and acute stress. This study aimed to characterize and examine relationships between insomnia, anxiety, and PA throughout the first year of the COVID-19 pandemic, when many lifestyle behaviors were disrupted.

METHODS

Participants comprised a convenience sample of 204 adults (55.4% female; 43.85 ± 15.85 years old) who completed the Generalized Anxiety Disorder Questionnaire (GAD-7), Insomnia Severity Index (ISI), and the International Physical Activity Questionnaire (IPAQ) at three time points through the first year of the COVID-19 pandemic. A cross-lagged panel model was used to evaluate these variables' concurrent, autoregressive, and cross-lagged relationships across time. Follow-up dynamic panel modeling using maximum likelihood and structural equation modeling was employed.

RESULTS

Approximately 64% of participants reported their work/occupation as affected by the pandemic. At baseline, associations between anxiety and insomnia were observed (β-coefficient: 15.87; p < 0.001). Insomnia was a positive future predictor of anxiety (ISI time point 2: 7.9 ± 5.6 points; GAD-7 at time point 3: 4.1 ± 4.2 points; β-coefficient: 0.16; p < 0.01). No associations were observed between PA and anxiety or insomnia (all p > 0.05).

CONCLUSIONS

Insomnia and anxiety were interrelated, and effects were cross-lagged. These data can inform future work focused on improving anxiety in settings of acute stress and disruptions to daily life, such as changes in occupational structure and stability. Specifically, targeting sleep parameters may be of interest to elicit downstream positive health behaviors.

Sleep loss disrupts decision-making ability and neuronal cytomorphology in zebrafish and the effects are mediated by noradrenaline acting on α1-adrenoceptor

Sleep is an instinct behavior, and its significance and functions are still an enigma. It is expressed throughout one's life and its loss affects psycho-somatic and physiological processes. We had proposed that it might maintain a fundamental property of the neurons and the brain. In that context, it was shown that sleep, rapid eye movement sleep (REMS) in particular, by regulating noradrenaline (NA), maintains the brain excitability. It was also reported that sleep-loss affected memory, reaction time and decision-making ability among others. However, as there was lack of clarity on the cause-and-effect relationship as to how the sleep-loss could affect these basic behaviors, their association was questioned and it was difficult to propose a cure or at least ways and means to ameliorate the symptoms. Also, we wanted to conduct the studies in a simpler model system so that conducting future molecular studies might be easier. Hence, using zebrafish as a model we evaluated if sleep-loss affected the basic decision-making ability, a cognitive process and if the effect was induced by NA. Indeed, our findings confirmed that upon sleep-deprivation, the cognitive decision-making ability of the prey zebrafish was compromised to protect itself by running away from the reach of the exposed predator Tiger Oscar (TO) fish. Also, we observed that upon sleep-loss the axonal arborization of the prey zebrafish brain was reduced. Interestingly, the effects were prevented by prazosin (PRZ), an α1-adrenoceptor (AR) antagonist and when the zebrafish recovered from the lost sleep.

The parasomnia defense in sleep-related homicide: A systematic review and a critical analysis of the medical literature

This review critically analyzes the forensic application of the Parasomnia Defense in homicidal incidents, drawing from medical literature on disorders of arousal (DOA) and rapid-eye-movement sleep behavior disorder (RBD). A systematic search of PubMed, Scopus, Embase, and Cochrane databases was conducted until October 16, 2022. We screened English-language articles in peer-reviewed journals discussing murders committed during sleep with a Parasomnia Defense. We followed PRISMA guidelines, extracting event details, diagnosis methods, factors influencing the acts, perpetrator behavior, timing, motives, concealment, mental experiences, victim demographics, and court verdicts. Three sleep experts evaluated each case. We selected ten homicides, four attempted homicides, and one homicide/attempted homicide that met inclusion/exclusion criteria. Most cases were suspected DOA as unanimously confirmed by experts. RBD cases were absent. Among aggressors, a minority reported dream-like experiences. Victims were primarily female family members killed in or near the bed by hands and/or with sharp objects. Objective sleep data and important crime scene details were often missing. Verdicts were ununiform. Homicides during DOA episodes, though rare, are documented, validating the Parasomnia Defense's use in forensics. RBD-related fatal aggression seems very uncommon. However, cases often lack diagnostic clarity. We propose updated guidelines to enhance future reporting and understanding of such incidents.

An EEG Signature of MCH Neuron Activities Predicts Cocaine Seeking

Background

Identifying biomarkers that predict substance use disorder (SUD) propensity may better strategize anti-addiction treatment. The melanin-concentrating hormone (MCH) neurons in the lateral hypothalamus (LH) critically mediates interactions between sleep and substance use; however, their activities are largely obscured in surface electroencephalogram (EEG) measures, hindering the development of biomarkers.

Methods

Surface EEG signals and real-time Ca2+ activities of LH MCH neurons (Ca2+MCH) were simultaneously recorded in male and female adult rats. Mathematical modeling and machine learning were then applied to predict Ca2+MCH using EEG derivatives. The robustness of the predictions was tested across sex and treatment conditions. Finally, features extracted from the EEG-predicted Ca2+MCH either before or after cocaine experience were used to predict future drug-seeking behaviors.

Results

An EEG waveform derivative - a modified theta-to-delta ratio (EEG Ratio) - accurately tracks real-time Ca2+MCH in rats. The prediction was robust during rapid eye movement sleep (REMS), persisted through REMS manipulations, wakefulness, circadian phases, and was consistent across sex. Moreover, cocaine self-administration and long-term withdrawal altered EEG Ratio suggesting shortening and circadian redistribution of synchronous MCH neuron activities. In addition, features of EEG Ratio indicative of prolonged synchronous MCH neuron activities predicted lower subsequent cocaine seeking. EEG Ratio also exhibited advantages over conventional REMS measures for the predictions.

Conclusions

The identified EEG Ratio may serve as a non-invasive measure for assessing MCH neuron activities in vivo and evaluating REMS; it may also serve as a potential biomarker predicting drug use propensity.

Genomic Insights into Dementia: Precision Medicine and the Impact of Gene-Environment Interaction

The diagnosis, treatment, and management of dementia provide significant challenges due to its chronic cognitive impairment. The complexity of this condition is further highlighted by the impact of gene-environment interactions. A recent strategy combines advanced genomics and precision medicine methods to explore the complex genetic foundations of dementia. Utilizing the most recent research in the field of neurogenetics, the importance of precise genetic data in explaining the variation seen in dementia patients can be investigated. Gene-environment interactions are important because they influence genetic susceptibilities and aid in the development and progression of dementia. Modified to each patient's genetic profile, precision medicine has the potential to detect groups at risk and make previously unheard-of predictions about the course of diseases. Precision medicine techniques have the potential to completely transform treatment and diagnosis methods. Targeted medications that target genetic abnormalities will probably appear, providing the possibility for more efficient and customized medical interventions. Investigating the relationship between genes and the environment may lead to preventive measures that would enable people to change their surroundings and minimize the risk of dementia, leading to the improved lifestyle of affected people. This paper provides a comprehensive overview of the genomic insights into dementia, emphasizing the pivotal role of precision medicine, and gene-environment interactions.

Promoting post-traumatic growth in cancer patients: a randomized controlled trial of guided written disclosure

Background

Cancer is a life-threatening disease that triggers not only vulnerability to distressing symptoms but also a meaning-making process that may lead to post-traumatic growth. As people often struggle to integrate cancer illness into their meaning system to reach an adaptive meaning, psychological interventions focused on a reappraisal of the illness experience can facilitate this process. This multicenter randomized controlled trial (RCT) was primarily aimed at assessing the efficacy of a writing intervention known as a guided disclosure protocol (GDP), compared to a generic writing intervention, in promoting post-traumatic growth in stage I-III breast and colon cancer patients at the end of their adjuvant chemotherapy.

Methods

Between January 2016 and August 2020 recruitment of eligible subjects took place during follow-up clinical consultations. Assessment occurred at baseline (T0), after the intervention (T1, 3 months from baseline), and at 6 months from baseline (T2). Both interventions consisted of three 20-min writing sessions to be performed once every two weeks. Change in post-traumatic growth was assessed using the Posttraumatic Growth Inventory, meaning with the Constructed Meaning Scale, and psychological distress with the Impact of Event Scale and the Hospital Anxiety and Depression Scale.

Results

In the five participating centers, 102 eligible patients were randomized and 72 participants completed follow-up evaluation. Most patients were women (79.4%), had breast cancer (68.6%), and stage I (27.5%), or stage II (44.1%) disease. Mean differences did not reach statistical significance for any of the dependent variables. However, an effect of the GDP, although not statistically relevant, was observed after the intervention in terms of enhanced post-traumatic growth and increased distress measured with the Impact of Event Scale.

Conclusion

This is the first RCT investigating the efficacy of a GDP in cancer patients having post-traumatic growth as the primary aim. Though GDP is a promising intervention in promoting post-traumatic growth, the lack of statistical significance of our findings may be due to the study being underpowered, hence this trial should be replicated with an adequate sample size, paying attention to supporting recruitment.

Clinical trial registration: ClinicalTrials.gov, identifier: 2015/0024360.

Translating and establishing the psychometric properties of the Jenkins Sleep Scale for Arabic-speaking individuals

BACKGROUND

The Jenkins Sleep Scale is a widely used self-report questionnaire that assesses sleep quality and disturbances. This study aimed to translate the scale into Arabic and evaluate its psychometric properties in an Arabic-speaking population.

METHODS

The Jenkins Sleep Scale was translated into Arabic using forward and backward translation procedures. The Arabic version was administered to a convenience sample of 420 adults along with the Pittsburgh Sleep Quality Index (PSQI) and Athens Insomnia Scale (AIS) for validation purposes. Reliability was examined using Cronbach's alpha and McDonald's omega coefficients. Confirmatory factor analysis (CFA) was also conducted to test the unidimensional factor structure. Convergent validity was assessed using correlations with PSQI and AIS scores.

RESULTS

The Cronbach's alpha and McDonald's omega values for the Arabic Jenkins Sleep Scale were 0.74 and 0.75, respectively, indicating good internal consistency. The 2-week and 4-week test-retest intraclass correlation coefficients were both 0.94 (p < 0.001), indicating excellent test-retest reliability. The CFA results confirmed the unidimensional factor structure (CFI = 0.99, TLI = 0.96, RMSEA = 0.08). The measurement model had an equivalent factor structure, loadings, intercepts, and residuals across sex, age, and marital status. Significant positive correlations were found between the Arabic Jenkins scale score and the PSQI (r = 0.80, p < 0.001) and AIS (r = 0.74, p < 0.001), supporting convergent validity.

CONCLUSION

The Arabic version of the Jenkins Sleep Scale demonstrated good psychometric properties. The findings support its use as a valid and reliable measure for evaluating sleep quality and disturbances among Arabic-speaking populations.

Are there effects of light exposure on daytime sleep for rotating shift nurses after night shift?: an EEG power analysis

Introduction

Night-shift workers often face various health issues stemming from circadian rhythm shift and the consequent poor sleep quality. We aimed to study nurses working night shifts, evaluate the electroencephalogram (EEG) pattern of daytime sleep, and explore possible pattern changes due to ambient light exposure (30 lux) compared to dim conditions (<5 lux) during daytime sleep.

Moethods

The study involved 31 participants who worked night shifts and 24 healthy adults who had never worked night shifts. The sleep macro and microstructures were analyzed, and electrophysiological activity was compared (1) between nighttime sleep and daytime sleep with dim light and (2) between daytime sleep with dim and 30 lux light conditions.

Results

The daytime sleep group showed lower slow or delta wave power during non-rapid eye movement (NREM) sleep than the nighttime sleep group. During daytime sleep, lower sigma wave power in N2 sleep was observed under light exposure compared to no light exposure. Moreover, during daytime sleep, lower slow wave power in N3 sleep in the last cycle was observed under light exposure compared to no light exposure.

Discussion

Our study demonstrated that night shift work and subsequent circadian misalignment strongly affect sleep quality and decrease slow and delta wave activities in NREM sleep. We also observed that light exposure during daytime sleep could additionally decrease N2 sleep spindle activity and N3 waves in the last sleep cycle.

Frontal P300 asymmetry and congruence judgment: Retroactive switching is impaired during school day mornings in female adolescents

Investigating frontal EEG asymmetry as a possible biomarker of cognitive control abilities is especially important in ecological contexts such as school and work. We used a novel approach combining judgment performance and hemispheric frontal event-related potential (ERP) P300 asymmetry (fP3As) to evaluate aspects of cognitive control (i.e., repetition and switching) in adolescent females over a two-week ordinary school period. While undergoing electroencephalographic recording, students performed a word-colour "Stroop-like" congruence judgment task during morning and afternoon sessions, on Mondays and Wednesdays. Proportion of incongruence and congruence trials was 75% and 25%, respectively. ERP analysis revealed larger "novelty" right hemispheric fP3As amplitude for infrequent congruence but equivalent or significantly smaller than left hemispheric fP3As amplitude for frequent incongruence. RTs increased with extent of right fP3As shift. Behaviorally, repeat trial pairs (i.e., congruent followed by congruent, incongruent followed by incongruent) generally did not differ by time or day and were associated with near-ceiling accuracy. In contrast, switch trial pairs (i.e., congruent followed by incongruent, incongruent followed by congruent) in the afternoon were slower and associated with lower accuracy at the expected 75% criterion rate (i.e., judging incongruence by default), dropping significantly below 75% in the mornings. Crucially, compared to afternoon, morning fP3As patterns did not change adaptively with switch trial pairs. Although retroactive switching during congruence judgment was affected at all testing times, we conclude it was most impaired in the mornings of both early and mid school weeks, supporting misalignment between adolescent circadian cycle and school start time. We discuss some implications for optimal learning of adolescents at school.

Sleep alterations as a function of 88 health indicators

BACKGROUND

Alterations in sleep have been described in multiple health conditions and as a function of several medication effects. However, evidence generally stems from small univariate studies. Here, we apply a large-sample, data-driven approach to investigate patterns between in sleep macrostructure, quantitative sleep EEG, and health.

METHODS

We use data from the MrOS Sleep Study, containing polysomnography and health data from a large sample (N = 3086) of elderly American men to establish associations between sleep macrostructure, the spectral composition of the electroencephalogram, 38 medical disorders, 2 health behaviors, and the use of 48 medications.

RESULTS

Of sleep macrostructure variables, increased REM latency and reduced REM duration were the most common findings across health indicators, along with increased sleep latency and reduced sleep efficiency. We found that the majority of health indicators were not associated with objective EEG power spectral density (PSD) alterations. Associations with the rest were highly stereotypical, with two principal components accounting for 85-95% of the PSD-health association. PC1 consists of a decrease of slow and an increase of fast PSD components, mainly in NREM. This pattern was most strongly associated with depression/SSRI medication use and age-related disorders. PC2 consists of changes in mid-frequency activity. Increased mid-frequency activity was associated with benzodiazepine use, while decreases were associated with cardiovascular problems and associated medications, in line with a recently proposed hypothesis of immune-mediated circadian demodulation in these disorders. Specific increases in sleep spindle frequency activity were associated with taking benzodiazepines and zolpidem. Sensitivity analyses supported the presence of both disorder and medication effects.

CONCLUSIONS

Sleep alterations are present in various health conditions.

Remote Evaluation of Sleep and Circadian Rhythms in Older Adults With Mild Cognitive Impairment and Dementia: Protocol for a Feasibility and Acceptability Mixed Methods Study

BACKGROUND

Sleep disturbances are a potentially modifiable risk factor for neurodegenerative dementia secondary to Alzheimer disease (AD) and Lewy body disease (LBD). Therefore, we need to identify the best methods to study sleep in this population.

OBJECTIVE

This study will assess the feasibility and acceptability of various wearable devices, smart devices, and remote study tasks in sleep and cognition research for people with AD and LBD.

METHODS

We will deliver a feasibility and acceptability study alongside a prospective observational cohort study assessing sleep and cognition longitudinally in the home environment. Adults aged older than 50 years who were diagnosed with mild to moderate dementia or mild cognitive impairment (MCI) due to probable AD or LBD and age-matched controls will be eligible. Exclusion criteria include lack of capacity to consent to research, other causes of MCI or dementia, and clinically significant sleep disorders. Participants will complete a cognitive assessment and questionnaires with a researcher and receive training and instructions for at-home study tasks across 8 weeks. At-home study tasks include remote sleep assessments using wearable devices (electroencephalography headband and actigraphy watch), app-based sleep diaries, online cognitive assessments, and saliva samples for melatonin- and cortisol-derived circadian markers. Feasibility outcomes will be assessed relating to recruitment and retention, data completeness, data quality, and support required. Feedback on acceptability and usability will be collected throughout the study period and end-of-study interviews will be analyzed using thematic analysis.

RESULTS

Recruitment started in February 2022. Data collection is ongoing, with final data expected in February 2024 and data analysis and publication of findings scheduled for the summer of 2024.

CONCLUSIONS

This study will allow us to assess if remote testing using smart devices and wearable technology is a viable alternative to traditional sleep measurements, such as polysomnography and questionnaires, in older adults with and without MCI or dementia due to AD or LBD. Understanding participant experience and the barriers and facilitators to technology use for research purposes and remote research in this population will assist with the development of, recruitment to, and retention within future research projects studying sleep and cognition outside of the clinic or laboratory.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/52652.