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To evaluate the association between headache, myofascial temporomandibular disorder (TMD), and awake bruxism (AB).Bruxism seems to act as a risk factor for TMD and its associated comorbidities, such as headaches.In total, 406 medical records of individuals who sought care at a university dental clinic were screened. The Research Diagnostic Criteria for Temporomandibular Disorders was used to assess and diagnose TMD, as well as to obtain self-reports of AB and headache.The sample consisted of 307 medical records. About 72.5% (221/305) of the sample reported having headaches, and 67.4% (180/267) and 68.4% (210/307) were diagnosed with AB and TMD, respectively. Individuals who reported having AB (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.09-4.7) and who were diagnosed with myofascial TMD (OR, 2.53; 95% CI, 1.15-5.5) were more likely to have had headaches in the past 6 months when compared with patients without myofascial TMD and bruxism. Also, individuals who self-reported headache were 2.27 times (95% CI, 1.09-4.7) more likely to have AB and 2.45 times (95% CI, 1.13-5.34) more likely to have myofascial pain than individuals without headaches.Individuals with myofascial TMD, headaches, or AB were more likely to have at least one of the other conditions.

Blood oxygenation level-dependent (BOLD) signals in the white matter (WM) have been demonstrated to encode neural activities by showing structure-specific temporal correlations during resting-state and task-specific imaging of fiber pathways with various degrees of correlations in strength and time delay. Previous neuroimaging studies have shown state-dependent functional connectivity and regional amplitude of signal fluctuations in brain gray matter across wakefulness and nonrapid eye movement (NREM) sleep cycles. However, the functional characteristics of WM during sleep remain unknown. Using simultaneous electroencephalography and functional magnetic resonance imaging data during wakefulness and NREM sleep collected from 66 healthy participants, we constructed 10 stable WM functional networks using clustering analysis. Functional connectivity between these WM functional networks and regional amplitude of WM signal fluctuations across multiple low-frequency bands were evaluated. In general, decreased WM functional connectivity between superficial and middle layer WM functional networks was observed from wakefulness to sleep. In addition, functional connectivity between the deep and cerebellar networks was higher during light sleep and lower during both wakefulness and deep sleep. The regional fluctuation amplitude was always higher during light sleep and lower during deep sleep. Importantly, slow-wave activity during deep sleep negatively correlated with functional connectivity between WM functional networks but positively correlated with fluctuation strength in the WM. These observations provide direct physiological evidence that neural activities in the WM are modulated by the sleep-wake cycle. This study provided the initial mapping of functional changes in WM during sleep.

The treatment of patients with disorders of consciousness (DoC) remains a challenging issue, and spinal cord stimulation (SCS) has been reported to be a promising treatment for DoC in some studies.This study explores the efficiency of SCS in treating patients with DoC at different consciousness levels, including the vegetative state/unresponsive wakefulness syndrome (VS/UWS) and the minimally conscious state (MCS) and summarizes and analyzes the long-term effect and related factors of SCS in patients with DoC.An overall positive outcome was reached in 35 of 110 patients (31.8%). Among patients with positive outcomes, the MCS group improved 45.53% more than VS/UWS group, and this difference was statistically significant. In terms of the recommendation standard, positive outcomes occurred in 33 patients (94.3%) in the highly recommended group and 2 patients (5.7%) in the weakly recommended group (p 0.001). After adjustment for potential covariables, young age (age ≤ 19 years old) (p = 0.045) and MCS (p 0.001) were significantly correlated with positive outcome. A nomogram based on age, state of consciousness, and pathogeny showed good predictive performance, with a c-index of 0.794. The Hosmer-Lemeshow goodness-of-fit test showed that the model was well calibrated (χSCS is one of the most feasible treatments for patients with DoC, especially for patients with MCS. Younger age is significantly associated with better outcomes and could therefore serve as a basis for preoperative screening. However, more evidence-based randomized controlled trials are needed to confirm the efficacy of the treatment.

Sleep is a universal and evolutionarily conserved behavior among many animal species, yet we do not have a fundamental understanding of why animals need to sleep. What we do know, however, is that sleep is critical for behavioral performance during the waking period and for long-term brain health. Here we provide an overview of some putative mechanisms that mediate the restorative effects of sleep, namely metabolic biosynthesis, fluid perfusion, and synaptic homeostasis. We then review recent experimental findings that advance the possibility of inducing sleep-like slow-wave activity (SWA) during wakefulness or enhance SWA during sleep in a top-down manner using noninvasive brain stimulation. SWA induction and SWA enhancement are believed to recapitulate the beneficial effects of sleep independent of the actual state of the subjects. If confirmed, these observations will change the way in which we investigate the neural correlates of sleep, thus paving the way for comprehending and actively controlling its restorative function.

Purpose To estimate dynamic off-resonance due to vigorous body motion in accelerated fMRI of awake behaving non-human primates (NHPs) using the standard EPI 3-line navigator, in order to attenuate the effects of time-varying off-resonance on the reconstruction. Methods In NHP fMRI the animal’s head is usually head-posted, and the dynamic off-resonance is mainly caused by motion in body parts that are distant from the brain and have low spatial frequency. Hence, off-resonance at each frame can be approximated as a spatially linear perturbation of the off-resonance at a reference frame, and is manifested as a relative linear shift in k-space. Using GRAPPA operators, we estimated these shifts by comparing the 3-line navigator at each time frame with that at the reference frame. Estimated shifts were then used to correct the data at each frame. The proposed method was evaluated in phantom scans, simulations, and in vivo data. Results The proposed method is shown to successfully estimate low-spatial order dynamic off-resonance perturbations, including induced linear off-resonance perturbations in phantoms, and is able to correct retrospectively corrupted data in simulations. Finally, it is shown to reduce ghosting artifacts and geometric distortions by up to 20% in simultaneous multi-slice in vivo acquisitions in awake-behaving NHPs. Conclusion A method is proposed that does not need any sequence modification or extra acquisitions and makes accelerated awake behaving NHP imaging more robust and reliable, reducing the gap between what is possible with NHP protocols and state-of-the-art human imaging.

Bronchospasm is a common respiratory adverse event in pediatric anesthesia. First line treatment commonly includes inhaled salbutamol. This review focusses on the current best practice to deliver aerosolized medications to awake as well as anesthetized pediatric patients and discusses the advantages and disadvantages of various administration techniques. Additionally, we detail the differences between various airway devices used in anesthesia. We highlight the unmet need for innovation of orally inhaled drug-products to deliver aerosolized medications during pediatric respiratory critical events such as bronchospasm. It is therefore important that clinicians remain up to date with the best clinical practice for aerosolized drug delivery in order to prevent and efficiently treat pediatric patients experiencing life-threatening respiratory emergencies.

Background and purpose Modafinil is a potent eugeroic (wakefulness-promoting) drug that is prescribed to treat narcolepsy and has a low incidence of abuse. Although previous studies have shown that modafinil-induced arousal depends on the dopamine receptors and transporters, the specific part/s of the dopamine transmitter system underlying this mechanism remained unclear. Here, we investigated the role of mesencephalic dopamine neurons in modafinil-evoked arousal. Experimental approach A dopamine indicator (dLight1.1) was employed to detect dopamine changes in the nucleus accumbens (NAc) and dorsal striatum. We specifically lesioned mesencephalic dopamine neurons via diphtheria toxin (DTA) in the dopamine transporter (DAT)-Cre mice. Then, the sleep-wake states were recorded to evaluate the effect of modafinil on arousal. Finally, the extent of DTA-induced lesions was determined by immunohistochemistry. Key results Modafinil promptly increased dopamine levels in the NAc and dorsal striatum in a dose-dependent manner. Lesioning of dopamine neurons in the substantia nigra pars compacta (SNc) or ventral tegmental area (VTA) had no significant effects on physiological sleep-wake cycles. Modafinil at 90 mg·kg-1 increased continuous wakefulness for 355 min in control mice. However, these effects were slightly decreased by 6.7% in the SNc-lesioned mice and were prominently diminished by 32.8% in VTA-lesioned mice. Furthermore, the modafinil-induced arousal was completely blocked in the SNc-VTA-lesioned mice, whereas lesions of the dorsal raphe nucleus had no effect. Conclusion and implications Taken together, our findings indicate that mesencephalic dopamine neurons are essential for modafinil-induced arousal.

The hippocampus is essential for spatial learning and memory. To assess learning we used contextual fear conditioning (cFC), where animals learn to associate a place with aversive events like foot-shocks. Candidate memory mechanisms for cFC are long-term potentiation and long-term depression, but there is little direct evidence of them operating in the hippocampus in vivo following cFC. Also, little is known about the behavioral state changes induced by cFC. To address these issues, we recorded local field potentials in freely behaving mice by stimulating in the left dorsal CA1 region and recording in the right dorsal CA1 region. Synaptic strength in the commissural pathway was monitored by measuring field excitatory postsynaptic potentials (fEPSPs) before and after cFC. After cFC, the commissural pathway’s synaptic strength was potentiated. Although recordings occurred during the wake phase of the light/dark cycle, the mice slept more in the post-conditioning period than in the pre-conditioning period. Relative to awake periods, in non-rapid eye movement (NREM) sleep the fEPSPs were larger in both pre- and post-conditioning periods. We also found a significant negative correlation between the animal’s speed and fEPSP size. Therefore, to avoid confounds in the fEFSP potentiation estimates, we controlled for speed-related and sleep-related fEPSP changes and still found that cFC induced long-term potentiation, but no significant long-term depression. Synaptic strength changes were not found in the control group that simply explored the fear-conditioning chamber, indicating that exploration of the novel place did not produce the measurable effects caused by cFC. These results show that following cFC, the CA1 commissural pathway is potentiated, likely contributing to the functional integration of the left and right hippocampi in fear memory consolidation. In addition, the cFC paradigm produces significant changes in an animal’s behavioral state, which are observable as proximal changes in sleep patterns.

Overnight sleep can reduce perceived stress, and improve associated cognitive disruptions and negative affect after an acute stressor. Whether a brief nap can also bestow these benefits in a non-sleep-restricted population is currently unknown. In this study that used a between-subjects design, stress was triggered by administering a modified Trier Social Stress Test to two groups of participants (nap [n = 29], wake [n = 41]). All participants were instructed they would give a speech during the study but the topic would be withheld until later, and then completed a math task. After a 40-min break in which participants watched a neutral video or took a nap monitored with electroencephalography, stress was reinforced by presenting the speech topics and giving participants a 10-min preparation period. Next, instead of giving a speech, the study ended and participants were debriefed. Negative affect, perceived stress and working memory were measured at multiple time points before and after the break. Both groups showed lower perceived stress and improved working memory after the break than before, but a nap did not confer additional benefits for perceived stress or working memory beyond taking a break. However, the nap group exhibited lower negative affect after the break than the wake group, and only the nap group showed a reduction in negative affect compared with initial negative affect levels. These results indicate a nap can improve negative emotions accompanying a stressor to a greater extent than taking a break, and suggest that brief naps may be a useful way to improve mood while experiencing an acute stressor.

Background Bruxism is a repetitive activity of the masticatory muscles that has been associated with orofacial disorders and psychosocial factors AIM: The aim of this study was to investigate associations between possible awake bruxism (PAB) and family functioning, bullying, and dental caries in children 8-10 years of age. Design A school-based study was conducted with 739 pairs of parents/guardians and children. The parents/guardians answered the Family Adaptability and Cohesion Evaluation Scales for the establishment of family functioning. Information on bullying due to dental conditions was collected from the children. Dental caries in the children was evaluated using International Caries Detection and Assessment System criteria. A directed acyclic graph was used to define the theoretical model and select control factors. Descriptive analysis was performed, followed by multivariate logistic regression for complex samples. Results Considering the parental reports, fewer years of mother's schooling, a low family income, very flexible family adaptability, and cavitated dental caries were associated with PAB. The female sex, bullying, and orofacial dysfunction were associated with self-reported PAB. Conclusions Therefore, the factors associated with PAB differ according to the reports of parents/guardians or self-reports of children. Healthcare providers should consider both reports for a more effective intervention addressing PAB.

Aims General anesthesia has been widely applied in surgical or nonsurgical medical procedures, but the mechanism behind remains elusive. Because of shared neural circuits of sleep and anesthesia, whether serotonergic system, which is highly implicated in modulation of sleep and wakefulness, regulates general anesthesia as well is worth investigating. Methods Immunostaining and fiber photometry were used to assess the neuronal activities. Electroencephalography spectra and burst‐suppression ratio (BSR) were used to measure anesthetic depth and loss or recovery of righting reflex to indicate the induction or emergence time of general anesthesia. Regulation of serotonergic system was achieved through optogenetic, chemogenetic, or pharmacological methods. Results We found that both Fos expression and calcium activity were significantly decreased during general anesthesia. Activation of 5‐HT neurons in the dorsal raphe nucleus (DRN) decreased the depth of anesthesia and facilitated the emergence from anesthesia, and inhibition deepened the anesthesia and prolonged the emergence time. Furthermore, agonism or antagonism of 5‐HT 1A or 2C receptors mimicked the effect of manipulating DRN serotonergic neurons. Conclusion Our results demonstrate that 5‐HT neurons in the DRN play a regulative role of general anesthesia, and activation of serotonergic neurons could facilitate emergence from general anesthesia partly through 5‐HT 1A and 2C receptors., General anesthesia decreases the activities of serotonergic neurons in the dorsal raphe. Activation of DRN 5‐HT neurons reduced the depth of anesthesia and accelerated the emergence from general anesthesia, partially through the 5‐HT 1A and 2C receptors.

Obstructive sleep apnea (OSA) is associated with abnormal cerebral perfusion at wakefulness, but whether these anomalies evolve over time is unknown. Here, we examined longitudinal changes in regional cerebral blood flow (rCBF) distribution in late middle‐aged and older adults with treated or untreated OSA. Twelve controls (64.8 ± 8.0 years) and 23 participants with newly diagnosed OSA (67.8 ± 6.2 years) were evaluated with polysomnography and cerebral 99mTc‐HMPAO single‐photon emission computed tomography during wakeful rest. OSA participants were referred to a sleep apnea clinic and 13 of them decided to start continuous positive airway pressure (CPAP). Participants were tested again after 18 months. Voxel‐based analysis and extracted relative rCBF values were used to assess longitudinal changes. Untreated OSA participants showed decreased relative rCBF in the left hippocampus and the right parahippocampal gyrus over time, while treated participants showed trends for increased relative rCBF in the left hippocampus and the right parahippocampal gyrus. No changes were found over time in controls. Untreated OSA is associated with worsening relative rCBF in specific brain areas over time, while treated OSA shows the opposite. Considering that OSA possibly accelerates cognitive decline in older adults, CPAP treatment could help reduce risk for cognitive impairment., Untreated OSA is associated with worsening relative rCBF in specific brain areas over time, while treated OSA shows the opposite. Considering that OSA possibly accelerates cognitive decline in older adults, CPAP treatment could help reduce risk for cognitive impairment.

In patients with intractable partial epilepsy who are eligible for epilepsy surgery, the best seizure control requires complete resection of the epileptogenic zone. When the epileptogenic zone is located very near to, or even with the eloquent cortex, this can be a challenge. In this study, we investigated the efficacy of awake craniotomy techniques to completely resect these epileptic zones while preserving the neural functions. We conducted a retrospective cohort study of 17 consecutive patients with intractable partial seizures of different aetiologies (non-lesional epilepsy [n=3], tuberous sclerosis [n=1], hypoxic ischaemic insult [n=1], dysembryoplastic neuroepithelial tumours [DNET] [n=2], focal cortical dysplasia type 2 [FCD] [n=4], and other malformations of cortical development [n=6]), located in eloquent language cortex (frontal [n=7], insular [n=5], and latero-temporal [n=5] regions). All patients were operated on between 2010 and 2019 for resective epilepsy surgery under awake conditions, with the aid of direct cortical stimulation. This report aimed to study the feasibility, efficacy and limitations of using the awake craniotomy technique for surgical resections of epileptogenic zones involving eloquent language cortex. Postoperative epilepsy control and neurological function were assessed and followed. The mean follow-up period was 5.7 years. In one patient, the surgery was aborted before resection. In the other patients, Engel Class I was achieved in seven patients (43.75%) and Engel Class II in four patients (25%), and worthwhile improvement (Engel Class I and II) was achieved in 11 patients (68.75%). Postoperative neurological deficits were encountered in four patients (23.5%). However, all these deficits were regressive and were absent at the last follow-up visit. Using the awake craniotomy technique, seizure freedom can be achieved in a high proportion of patients with epileptogenic zones located in language areas, who were previously considered only candidates for palliative measures.

The aim of this study was to clarify the effect of a stable concentration of propofol on interictal high-frequency oscillations (HFOs), which may contribute to identifying the epileptogenic zone intraoperatively for resection surgery. Nine patients with drug-resistant focal epilepsy who underwent invasive pre-surgical evaluation with chronic subdural electrodes were recruited. Five-minute electrocorticograms during wakefulness, slow-wave sleep, and under a stable brain concentration of propofol were recorded with the same electrodes. In each patient, 1-10 pairs of electrodes were selected for both electrodes with EEG changes within 5 seconds from the ictal onset (ictal pattern for 5 seconds [IP5]) and those outside the area of IP5 with no interictal epileptiform discharges (non-epileptiform [nEPI]). The numbers of ripples (80-250 Hz) and fast ripples (>250 Hz) were measured semi-automatically using an established algorithm. Statistical testing was performed with a mixed effect model. Thirty-seven pairs of electrodes from nine patients were analysed for IP5 and 29 pairs from seven patients were analysed for nEPI. The numbers of HFOs differed between the areas (IP5 and nEPI) and among the conditions (wakefulness, slow-wave sleep, propofol anaesthesia) (all p

KEY POINTS Sudden unexpected death in epilepsy (SUDEP) is the leading cause of premature death in patients with refractory epilepsy. SUDEP typically occurs during the night, although the reason for this is unclear. We found that, in normally entrained mice, time-of-day alters vulnerability to seizure-induced death. We found that, in free-running mice, circadian phase alters the vulnerability to seizure-induced death. These findings suggest that circadian rhythmicity may be responsible for the increased night-time prevalence of SUDEP ABSTRACT: Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related death. SUDEP typically occurs during the night following a seizure. Many aspects of mammalian physiology are regulated by circadian rhythms in ways that might make seizures occuring during the night more dangerous. Using two mouse models of seizure-induced death, we demonstrate that time-of-day and circadian rhythms alter vulnerability to seizure-induced death. We exposed normally entrained DBA/1 mice to a potentially seizure-inducing acoustic stimulus at different times of day and compared the characteristics and outcomes of the seizures. Time-of-day did not alter the probability of a seizure but it did alter the probability of seizure-induced death. To determine whether circadian rhythms alter vulnerability to seizure-induced death, we induced maximal electroshock seizures in free-running C57BL/6J mice at different circadian time points at the same time as measuring breathing via whole body plethysmography. Circadian phase did not affect seizure severity but it did alter postictal respiratory outcomes and the probability of seizure-induced death. By contrast to our expectations, in entrained and free-running mice, vulnerability to seizure-induced death was greatest during the night and subjective night, respectively. These findings suggest that circadian rhythmicity may be responsible for the increased night-time prevalence of SUDEP and that the underlying mechanism is phase conserved between nocturnal and diurnal mammals. All of the seizures in the present study were induced during wakefulness, indicating that the effect of time point on vulnerability to seizure-induced death was not the result of sleep. Understanding why SUDEP occurs more frequently during the night may inform future preventative countermeasures.

Aim Separating infants and their parents after a Caesarean section is still the routine care worldwide. This study investigated three caregiving models on the wakefulness and physiological parameters of full‐term infants after an elective Caesarean section. Methods Newborn infants born in a Chilean public hospital in 2009‐12 were randomised to three groups: cot, fathers' arms or skin‐to‐skin contact with their father. They were assessed at 15‐minute intervals, from 45 to 120 minutes after the Caesarean section. Their physiological parameters were measured, and their wakefulness was assessed using the Neonatal Behavioural Assessment Scale. Results We studied 95 infant (53% girls) born at a mean gestational age of 38.9 ± 0.9 weeks. Heart rates were significantly higher in the skin‐to‐skin than cot or fathers' arms groups and showed greater stability over time. Wakefulness was initially higher in the skin‐to‐skin group, but there were no significant differences by the end of the observation. There were no differences between the groups in peripheral oxygen saturation. Skin‐to‐skin contact had no negative impact on the infants. Conclusion The skin‐to‐skin group showed some advantages over the cot and fathers' arms groups when it came to establishing stable physiological parameters and wakefulness. This approach should be supported during mother‐infant separation.

Introduction The influence of aligners on the activity of the masticatory muscles is still controversial, especially regarding the behaviour associated with awake bruxism (AB). Objective To compare the frequency of AB behaviours between patients treated with aligners and fixed appliances. Methods The sample comprised 38 Class I patients (mean age 22.08 years), divided by simple randomisation into two groups: OA group; orthodontic aligners (n 19) and FA group; fixed appliance (n 19). The frequency of AB was investigated by the ecological momentary assessment using an online device (mentimeter), during 7 following days at different timepoints, before and after appliance placement and in the 2nd, 3rd, 4th and 6th months of orthodontic treatment. These variables were also evaluated: level of anxiety by the State-Trait Anxiety Inventory, stress by the Perceived Stress Scale, catastrophising related to pain and degree of hypervigilance by the Pain Vigilance and Awareness Questionnaire, and the presence of facial pain evaluated by the DC/TMD. Results There was no difference between groups in the frequency of AB behaviours, with mean of 53.5% for group OA and 51.3% for FA. The most frequent behaviour was slightly touching the teeth, and in FA group, there was a significant reduction in this behaviour soon after appliance placement. The groups did not differ concerning the degree of anxiety, stress, catastrophising, hypervigilance and facial pain. Conclusion The orthodontic treatment performed with aligners or fixed appliances did not influence the frequency of AB during the 6 months of treatment. REGISTRY OF CLINICAL TRIALS: (REBEC): RBR-9zytwf.

Objective To characterize the clinical presentation of sleep-disordered breathing and respiratory patterns at rest and during a 6-minute walk test (6MWT) in children with rapid-onset obesity, hypothalamic dysfunction, hypoventilation and autonomic dysregulation (ROHHAD) syndrome. Methods Retrospective study of children with ROHHAD who had a diagnostic baseline polysomnography, daytime cardiorespiratory monitoring at rest and a 6MWT. Polysomnography data were also compared with BMI-, age- and sex-matched controls. Results Of the 8 children with ROHHAD, all 8 (100%) had obstructive sleep apnea (OSA) and 2/8 (25%) had nocturnal hypoventilation on their baseline polysomnography. Comparing the ROHHAD group to the control group, there were no significant differences in the median [IQR] obstructive apnea-hypopnea index (OAHI) (11.1 [4.3-58.4] vs 14.4 [10.3-23.3] events/hour, respectively; p=0.78). However, children with ROHHAD showed a significantly higher desaturation index compared to the control group (37.9 [13.7-59.8] vs 14.7 [4.3-27.6] events/hour; p=0.05). While awake at rest, some children with ROHHAD experienced significant desaturations associated with central pauses. During the 6MWT, no significant desaturations were observed, but two children showed moderate functional limitation. Conclusions Among children with ROHHAD, respiratory instability may be demonstrated by a significant number and severity of oxygen desaturations during sleep in the presence of OSA, with or without nocturnal hypoventilation, and oxygen desaturations with central pauses at rest during wakefulness. Interestingly, during daily activities that require submaximal effort, children may not experience oxygen desaturations. Early recognition of respiratory abnormalities and targeted therapeutic interventions are important to limit associated morbidity and mortality in ROHHAD. This article is protected by copyright. All rights reserved.

Sleep is critical for health, cognition, and restorative processes, and yet, many experience chronic sleep restriction. Sleep interventions have been designed to enhance overnight sleep quality and physiology. Components of these interventions, like relaxation-based progressive muscle relaxation (PMR), have been studied in isolation and have shown direct effects on sleep architecture, including increasing time in restorative, slow-wave sleep (SWS). These relaxation methods have been understudied in naps, which are effective fatigue countermeasures that reduce deleterious effects of chronic sleep restriction. We hypothesised that PMR should boost SWS in a nap, as compared to an active control. We used a between-subject design in which healthy young adults underwent PMR training or listened to Mozart music (control) prior to a 90-min nap opportunity. We assessed changes in the amount and lateralisation of SWS, as evidence suggests left hemispheric lateralisation may be a proxy for recuperative sleep needs, and changes to state-dependent anxiety and fatigue before and after the nap to assess intervention success. We found PMR participants spent ~10 min more in SWS, equivalent to 125% more time, than the control group, and concomitantly, significantly less time in rapid eye movement sleep. PMR participants also had greater right lateralised slow-wave activity and delta activity compared to the control suggesting a more well-rested brain profile during sleep. Further, pre-sleep anxiety levels predicted nap architecture in the intervention group, suggesting benefits may be impacted by anxiety. The feasibility and accessibility of PMR prior to a nap make this an interesting research avenue to pursue with strong translational application.

Background Awake prone positioning has been widely used in patients with COVID-19 respiratory failure to avoid intubation despite limited evidence. Our objective was to evaluate if prone positioning is associated with a reduced intubation rate when compared to usual care. Methods This was a retrospective cohort study in the emergency department of a large quaternary hospital in Sao Paulo. We retrieved data from all admitted patients in need of oxygen supplementation (>3 L/min) and tachypnea (>24 ipm) from March 1 to April 30, 2020, excluding those who had any contraindication to the prone position or who had an immediate need for intubation. The primary endpoint was endotracheal intubation up to 15 days. Secondary outcomes included a 6-point clinical outcome ordinal scale, mechanical ventilation-free days, admission to the intensive care unit, and need of hemodialysis and of vasoactive drugs, all assessed at or up to 15 days. We analyzed unadjusted and adjusted effect estimates with Cox proportional hazards models, logistic regression, quantile regression, and sensitivity analyses using propensity score models. Results Of 925 suspected COVID-19 patients admitted off mechanical ventilation, 166 patients fulfilled inclusion and exclusion criteria: 57 were exposed to prone positioning and 109 to usual care. In the intervention group, 33 (58%) were intubated versus 53 (49%) in the control group. We observed no difference in intubation rates in the univariate analysis (hazard ratio = 1.21, 95% confidence interval [CI] = 0.78 to 1.88, p = 0.39) nor in the adjusted analysis (hazard ratio = 0.90, 95% CI = 0.55 to 1.49, p = 0.69). Results were robust to the sensitivity analyses. Secondary outcomes did not differ between groups. Conclusions Awake prone positioning was not associated with lower intubation rates. Caution is necessary before widespread adoption of this technique, pending results of clinical trials.

BACKGROUND: The medial prefrontal cortex (mPFC) is a brain region involved in the evaluation and selection of motivationally relevant outcomes. Neural activity in mPFC is altered following acute ethanol (EtOH) use and, in rodent models, doses as low as 0.75 g/kg yield cognitive deficits. Deficits in decision-making following acute EtOH are thought to be mediated, at least in part, by decreases in mPFC firing rates (FRs). However, the data leading to this conclusion have been generated exclusively in anesthetized rodents. The present study characterizes the effects of acute EtOH injections on mPFC neural activity in awake-behaving rodents. METHODS: Awake-behaving and anesthetized in vivo electrophysiological recordings were performed. We utilized three groups: the first received two saline injections, the second received a saline injection followed by 1.0 g/kg EtOH, the last received saline followed by 2 g/kg EtOH. One week later an anesthetized recording occurred where a saline injection was followed by an injection of 1.0 g/kg EtOH. RESULTS: The anesthetized condition showed robust decreases in neural activity and differences in up-down state dynamics. In the awake-behaving condition, FRs were grouped according to behavioral state: moving, not moving, and sleep. The differences in median FRs were found for each treatment and behavioral state combination. A FR decrease was only found in the 2.0 g/kg EtOH treatment during not moving states. However, robust decreases in FR variability were found across behavioral state in both the 1.0 g/kg and 2.0 g/kg EtOH treatment. Sleep was separately analyzed. EtOH modulated the up-down states during sleep producing decreases in FRs. CONCLUSIONS: In conclusion, the changes in neural activity following EtOH administration in anesthetized animals are not conserved in awake-behaving animals. The most prominent difference following EtOH was a decrease in FR variability suggesting that acute EtOH may be affecting decision-making via this mechanism.

Insomnia disorder is the most common sleep disorder and has drawn increasing attention. Many studies have shown that hyperarousal plays a key role in the pathophysiology of insomnia disorder. However, the specific brain mechanisms underlying insomnia disorder remain unclear. To elucidate the neuropathophysiology of insomnia disorder, we investigated the brain functional networks of patients with insomnia disorder and healthy controls across the sleep–wake cycle. EEG‐fMRI data from 33 patients with insomnia disorder and 31 well‐matched healthy controls during wakefulness and nonrapid eye movement sleep, including N1, N2 and N3 stages, were analyzed. A medial and anterior thalamic region was selected as the seed considering its role in sleep–wake regulation. The functional connectivity between the thalamic seed and voxels across the brain was calculated. ANOVA with factors “group” and “stage” was performed on thalamus‐based functional connectivity. Correlations between the misperception index and altered functional connectivity were explored. A group‐by‐stage interaction was observed at widespread cortical regions. Regarding the main effect of group, patients with insomnia disorder demonstrated decreased thalamic connectivity with the left amygdala, parahippocampal gyrus, putamen, pallidum and hippocampus across wakefulness and all three nonrapid eye movement sleep stages. The thalamic connectivity in the subcortical cluster and the right temporal cluster in N1 was significantly correlated with the misperception index. This study demonstrated the brain functional basis in insomnia disorder and illustrated its relationship with sleep misperception, shedding new light on the brain mechanisms of insomnia disorder and indicating potential therapeutic targets for its treatment., Thalamus‐based connectivity in patients with insomnia disorder and healthy controls during wakefulness and sleep was analyzed. A group‐by‐stage interaction was observed at widespread cortical regions. Regarding the main effect of group, patients with insomnia disorder demonstrated decreased thalamic connectivity with the left amygdala, parahippocampal gyrus, putamen, pallidum, and hippocampus across wakefulness and all three nonrapid eye movement sleep stages.

Background A definitive diagnosis of congenital central hypoventilation syndrome (CCHS) is made by genetic testing. However, there are only a few examinations that warrant genetic testing. Electrical activity of the diaphragm (Edi) reflects neural respiratory drive from respiratory center to diaphragm. We evaluated the function of the respiratory center in CCHS by Edi monitoring. Methods Monitoring of Edi was performed in six CCHS cases without mechanical ventilation. The monitoring time was 30 consecutive minutes from wakefulness to sleep. The TcPCO2 or EtCO2 and SpO2 were recorded simultaneously. Results The Edi peak during wakefulness was 14.0 (10.3-21.0) µV and the Edi peak during sleep was 6.7 (3.8-8.0) µV. The Edi peak during sleep was significantly lower than the Edi peak during wakefulness, and patients were in a state of hypoventilation. Although TcPCO2 or EtCO2 increased due to hypoventilation, an increase in the Edi peak that reflects central respiratory drive was not observed. ΔEdi/ΔCO2 was -0.06μV/mmHg. Maximum EtCO2 or TcPco2 was 51 mmHg, and the average SpO2 was 91.5% during monitoring. Conclusions We confirmed that Edi monitoring could evaluate the function of the respiratory center and reproduce the hypoventilation of CCHS. The present study suggested that Edi monitoring is a useful examination in deciding whether to perform genetic testing or not and it may lead to an early diagnosis of CCHS.

Pitt-Hopkins syndrome is a rare genetic disease, characterised by severe intellectual disability, distinctive dysmorphic features, epilepsy and distinctive breathing abnormalities during wakefulness. Here, we describe the case of a 22-year-old woman with Pitt-Hopkins syndrome who presented with intractable generalised tonic seizures from the age of 11 years, which increased in frequency with age and onset of menstruation despite usage of some anticonvulsant drugs. From the age of 16 years, polysomnography and video-EEG led to the detection of frequent epileptic apnoea during sleep. Although the frequency of generalised tonic seizure clusters was reduced by treatment with phenobarbital and potassium bromide, epileptic apnoea persisted. Furthermore, frequent epileptic apnoea observed in our patient was regarded as a factor for aspiration and deterioration of respiratory function. This study indicates that patients with Pitt-Hopkins syndrome require close monitoring for epileptic apnoea. Moreover, long-term EEG and respiratory monitoring are necessary to distinguish epileptic apnoea from other respiratory disorders in patients with Pitt-Hopkins syndrome.

Histamine plays pleiotropic roles as a neurotransmitter in the physiology of brain function, this includes the maintenance of wakefulness, appetite regulation and memory retrieval. Since numerous studies have revealed an association between histaminergic dysfunction and diverse neuropsychiatric disorders, such as Alzheimer's disease and schizophrenia, a large number of compounds acting on the brain histamine system have been developed to treat neurological disorders. In 2016, pitolisant, which was developed as a histamine H3 receptor inverse agonist by Schwartz and colleagues, was launched for the treatment of narcolepsy, emphasising the prominent role of brain histamine on wakefulness. Recent advances in neuroscientific techniques such as chemogenetic and optogenetic approaches have led to remarkable progress in the understanding of histaminergic neural circuits essential for the control of wakefulness. In this review article, we summarise the basic knowledge about the histaminergic nervous system and the mechanisms underlying sleep/wake regulation that are controlled by the brain histamine system. LINKED ARTICLES: This article is part of a themed issue on Neurochemistry in Japan. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.4/issuetoc.

BACKGROUND In the monitored anesthesia care (MAC) setting for awake craniotomy (AC), maintaining airway patency in sedated patients remains challenging. This randomized controlled trial aimed to compare the validity of the below-epiglottis transnasal tube insertion (the tip of the tube placed between the epiglottis and vocal cords) and the nasopharyngeal airway (simulated by the above-epiglottis transnasal tube with the tip of the tube placed between the epiglottis and the free edge of the soft palate) with respect to maintaining upper airway patency for moderately sedated patients undergoing AC. METHODS Sixty patients scheduled for elective AC were randomized to receive below-epiglottis (n = 30) or above-epiglottis (n = 30) transnasal tube insertion before surgery. Moderate sedation was maintained in the pre- and post-awake phases. The primary outcome was the upper airway obstruction (UAO) remission rate (relieved obstructions after tube insertion/the total number of obstructions before tube insertion). RESULTS The UAO remission rate was higher in the below-epiglottis group [100% (12/12) vs 45% (5/11); P = .005]. The tidal volume values monitored through the tube were greater in the below-epiglottis group during the pre-awake phase (P

Automated office blood pressure measurement eliminates the white coat effect and is associated with awake ambulatory blood pressure. This study examined whether automated office blood pressure values at lower limits were comparable to those of awake and mean 24‐hour ambulatory blood pressure. A total of 552 patients were included in the study, involving 293 (53.1%) men and 259 (46.9%) women, with a mean age 55.0 ± 12.5, of whom 36% were treated for hypertension. Both systolic and diastolic automated office blood pressures exhibited lower values compared to awake ambulatory blood pressure among 254 individuals with systolic automated office blood pressure

Spinal cord injury (SCI) is a common cause of disability, which often leads to sensorimotor cortex dysfunction above the spinal injury site. However, the cerebral regional effects on metabolic information after SCI have been little studied. Here, adult Sprague-Dawley rats were divided into acute and chronic treatment groups and sham groups with day-matched periods. The Basso, Beatte, and Bresnahan scores method were utilized to evaluate the changes in behaviors during the recovery of the animals, and the metabolic information was measured with the 1 H-observed/13 C-edited NMR method. Total metabolic concentrations in every region were almost similar in both treated groups. However, the metabolic kinetics in most regions in the acute group were significantly altered (P < .05), particularly in the cortical area, thalamus and medulla (P < .01). After long-term recovery, some metabolic kinetics were recovered, especially in the temporal cortex, occipital cortex, and medulla. The metabolic kinetic changes revealed the alteration of metabolism and neurotransmission in different brain regions after SCI, which present evidence for the alternation of brain glucose oxidation. Therefore, this shows the significant influence of SCI on cerebral function and neuroscience research. This study also provides the theoretical basis for clinical therapy after SCI, such as mitochondrial transplantation. \ud \ud Keywords: NMR; brain regions; metabolic kinetics; neurotransmitters; spinal cord injury.

OBJECTIVES/HYPOTHESIS: To examine the correlation between transoral and awake endoscopic examination and investigate their respective ability to predict outcomes of hypoglossal nerve stimulation (HGNS). STUDY DESIGN: Retrospective cohort study at a US medical center. METHODS: Subjects were adults with apnea-hypopnea index (AHI) >15 events/hr who underwent HGNS according to standard indications. Eligible subjects had diagnostic preoperative sleep studies, full-night efficacy postoperative studies, as well as postoperative video recordings of transoral examination and awake endoscopy. Recordings were independently scored by two blinded reviewers. Cohen’s κ coefficient, Student t test, and χ(2) analyses were performed. RESULTS: Fifty-seven patients met all inclusion criteria. On average, patients were Caucasian, middle aged, and overweight. The mean preoperative AHI was 36.7 events/hr, which improved significantly to 18.3 events/hr following HGNS (P < .01). Overall, the response rate (defined as AHI reduction >50% and AHI < 20 events/hr) was 49%. There was slight correlation between transoral tongue protrusion and endoscopic tongue base movement (κ = 0.10). On transoral examination, patients with minimal/moderate tongue motion achieved a greater mean AHI reduction than patients with full motion (26.0 ± 18.0 vs. 12.8 ± 24.1, P = .02). In contrast, on awake endoscopy, patients with minimal/moderate tongue motion achieved a lesser mean AHI reduction than patients with full motion (8.7 ± 19.9 vs. 22.1 ± 22.7, P = .04). CONCLUSIONS: Transoral tongue protrusion bears an inverse relationship to HGNS success and correlates poorly with endoscopic tongue base movement. Endoscopic tongue base motion appears reflective of response to HGNS, with greater motion corresponding to greater AHI reduction.

To evaluate the efficacy and safety of the Shikani optical stylet (SOS) versus fiberoptic bronchoscope (FOB) for awake nasal intubation in head and neck surgery patients with an anticipated difficult airway.Prospective randomized clinical trial.This study involved 50 adult patients scheduled for elective head and neck surgery and presented with an anticipated difficult airway. Patients planned for awake nasotracheal intubation were randomly divided into two groups: FOB (n = 25) and SOS (n = 25). Patients were intubated under local anesthesia and sedation using the randomly assigned intubation device by anesthetists proficient in both airway devices. The time to successful intubation was regarded as the primary endpoint.The median time (interquartile range) to tracheal intubation in the FOB group was 74 seconds (57-108) and 38 seconds (27-60) in the SOS group (P .001). Intubation success rates on the first attempt in the FOB and SOS groups were 96% and 92%, respectively (P .999). Airway assisted maneuvers were required in six (24%) SOS intubations compared to 21 (84%) FOB intubations (P .001). There were no significant differences between the groups in the incidences of oxygen desaturation and postoperative complications related to intubation.Compared to the FOB group, awake nasal intubation in the SOS group required significantly less time and fewer airway-assisted maneuvers on adult head and neck surgery patients with anticipated difficult airway.2 Laryngoscope, 131:319-325, 2021.

Objective High-frequency deep brain stimulation (DBS) of anterior thalamic nuclei (ANT) reduces the frequency and intensity of focal and focal to bilateral tonic-clonic epileptic seizures. We investigated the impact of high-frequency ANT-DBS on vigilance in epilepsy patients during relaxed and drowsy wakefulness, to better understand the effects and the mechanisms of action of this intervention in humans. Methods Four patients with different structural epileptic pathologies were included in this retrospective case-cohort study. Short- and long-term electroencephalography (EEG) was used to determine states of relaxed or drowsy wakefulness and the vigilance changes during stimulation-on and stimulation-off intervals. Results In relaxed, wakeful patients with eyes closed, the eyelid artifact rate increased acutely and reproducibly during stimulation-on intervals, suggesting an enhanced vigilance. This effect was accompanied by a slight acceleration of the alpha rhythm. In drowsy patients with eyes closed, stimulation generated acutely and reproducibly alpha rhythms, similar to the paradoxical alpha activation during eyes opening. The occurrence of the alpha rhythms reflected an increase in the vigilance of the drowsy subjects during ANT-DBS. Significance This is the first demonstration that ANT-DBS increases the vigilance of wakeful epilepsy patients. Our results deliver circumstantial evidence that high-frequency ANT-DBS activates thalamocortical connections that promote wakefulness.

In this age of 'fake news', it is crucial that children are equipped with the skills to identify unreliable information online. Our study is the first to examine whether children are influenced by the presence of inaccuracies contained in webpages when deciding which sources to trust. Forty-eight 8- to 10-year-olds viewed three pairs of webpages, relating to the same topics, where one webpage per pair contained three obvious inaccuracies (factual, typographical, or exaggerations, according to condition). The paired webpages offered conflicting claims about two novel facts. We asked participants questions pertaining to the novel facts to assess whether they systematically selected answers from the accurate sources. Selective trust in the accurate webpage was found in the typos condition only. This study highlights the limitations of 8- to 10-year-olds in critically evaluating the accuracy of webpage content and indicates a potential focus for educational intervention. Statement of contribution What is already known on this subject? Children display early epistemic vigilance towards spoken testimony. They use speakers' past accuracy when deciding whom to trust regarding novel information. Little is known about children's selective trust towards web-based sources. What does this study add? This study is the first to examine whether textual inaccuracy affects children's trust in webpages. Typos but not semantic errors led to reduced trust in a webpage compared to an accurate source. Children aged 8-10 years show limited evaluation of the accuracy of online content.

Background Gastroesophageal reflux disease may be an important risk factor for awake bruxism. Additionally, it has been known that a psychological stress task affects masseter muscle activity, and autonomic nervous system (ANS) activity modulation induces masseter muscle activity. Objectives This study aimed to investigate whether task-induced stress and experimental oesophageal acid infusion increase masseter muscle activity and alter ANS activity, compared to rest task and oesophageal saline infusion, respectively. Methods Polygraphic monitoring, consisting of electromyography of the masseter muscle and electrocardiography, was performed in 12 healthy adult men during 30-min interventions with intra-oesophageal saline or acid infusion, while reading a book quietly, as rest, and while performing calculation, as a stress task. Results At rest, masseter muscle activity and parasympathetic nervous system (PNS) activity during acid infusion were significantly higher (P = .019) and lower (P = .021) than during saline infusion, respectively. During saline infusion, both masseter muscle activity and sympathetic nervous system (SNS) activity or PNS activity while performing the calculation task were higher (P = .022 and .012, respectively) or lower (P = .007) than those during the reading task, respectively. In two-way repeated-measures ANOVA, intra-oesophageal infusion (saline or acid) significantly affected masseter muscle activity (P = .008) and PNS activity (P = .021). However, performing tasks (reading or calculation) significantly affected only PNS activity (P = .028). Conclusion Intra-oesophageal acid infusion significantly increased masseter muscle activity and decreased PNS activity. In contrast, stress task not only significantly decreased PNS activity, but only modestly increased masseter muscle activity and SNS activity.

Objectives Determine the rates of, reasons for, and effectiveness of device reprogramming utilizing in-office awake endoscopy (AE) in subjects who underwent upper airway stimulation (UAS) surgery. Study design Retrospective chart review. Methods Retrospective chart review at a tertiary care center on patients implanted with UAS devices from November 2015 to July 2018. Results Sixty patients were implanted with UAS devices. Average pre- and postsurgical total apnea-hypopnea index (AHI) was 40.6 and 4.2 with a 36.4 total AHI reduction. Treatment success based on Sher criteria was observed in 88% of patients. Postoperative titration polysomnography revealed an average functional threshold (FT) and minimum therapeutic amplitude (MTA) of 1.6 and 2.1 V, respectively. A total of 24 AEs were performed in 19 (32%) patients. The most common complaints and reasons for AE were perceived stimulus discomfort (42%), frequent awakenings (32%), and persistent fatigue or non-normalized AHI (21%). After first AE, there was a 0.87 (53%) and 0.93 (45%) V reduction in FT and MTA, respectively. Conclusion Patients with obstructive sleep apnea continue to succeed with UAS. Fewer than one-third of patients had postsurgical complaints requiring device reconfiguration utilizing AE to assess the pharyngeal airway and optimize device settings. Reduction in the FT and MTA after AE may improve compliance by reducing discomfort and frequent awakenings. Periodic monitoring of patients with implanted UAS devices is necessary to optimize efficacy and maintain patient compliance. Level of evidence 4 Laryngoscope, 130:2494-2498, 2020.

Background Pain and discomfort during the awake phase in awake craniotomy should be relieved to facilitate brain mapping. Although some anaesthesiologists use low-dose (0.01-0.05 µg/kg/min) remifentanil infusion to provide analgesia during this phase, its efficacy and side effects have never been evaluated. Therefore, this study primarily aimed to investigate the effects of low-dose remifentanil infusion on the need for antiemetic treatment during brain mapping and secondarily aimed to determine its effects on the need for additional analgesic treatment. Methods This retrospective study included 218 patients who underwent awake craniotomy at our centre from 2008 to 2018. The relationship between low-dose remifentanil infusion during the awake phase and the requirement for analgesic or antiemetic treatment was examined. A multivariable competing risk regression analysis was performed to adjust for patient and operative variables. Results Sixty-six patients (30.3%) received low-dose (median rate: 0.01 µg/kg/min) remifentanil infusion during the awake phase. Forty-nine patients (22.5%) received an antiemetic and 99 (45.4%) received additional analgesic treatment. The difference in additional analgesic treatment was not significant between patients who received low-dose remifentanil infusion and those who did not (adjusted hazard ratio: 1.13; 95% confidence interval: 0.75-1.70; P = .570); however, the use of antiemetics significantly increased in patients who received remifentanil (adjusted hazard ratio: 1.78; 95% confidence interval: 1.01-3.15; P = .047). Conclusion Low-dose remifentanil infusion during the awake phase in awake craniotomy significantly increased the need for antiemetics but did not decrease the need for additional analgesic treatment.

Traditionally, preclinical resting state functional magnetic resonance imaging (fMRI) studies have been performed in anesthetized animals. Nevertheless, as anesthesia affects the functional connectivity (FC) in the brain, there has been a growing interest in imaging in the awake state. Obviously, awake imaging requires resource- and time-consuming habituation prior to data acquisition to reduce the stress and motion of the animals. Light sedation has been a less widely exploited alternative for awake imaging, requiring shorter habituation times, while still reducing the effect of anesthesia. Here, we imaged 102 rats under light sedation and 10 awake animals to conduct an FC analysis. We established an automated data-processing pipeline suitable for both groups. Additionally, the same pipeline was used on data obtained from an openly available awake rat database (289 measurements in 90 rats). The FC pattern in the light sedation measurements closely resembled the corresponding patterns in both onsite and offsite awake datasets. However, fewer datasets had to be excluded due to movement in rats with light sedation. The temporal analysis of FC in the lightly sedated group indicated a lingering effect of anesthesia that stabilized after the first 5 min. In summary, our results indicate that the light sedation protocol is a valid alternative for large-scale studies where awake protocols may become prohibitively resource-demanding, as it provides similar results to awake imaging, preserves more scans, and requires shorter habituation times. The large amount of fMRI data obtained in this work are openly available for further analyses.

Summary Awake tracheal intubation has a high success rate and a favourable safety profile but is underused in cases of anticipated difficult airway management. These guidelines are a comprehensive document to support decision making, preparation and practical performance of awake tracheal intubation. We performed a systematic review of the literature seeking all of the available evidence for each element of awake tracheal intubation in order to make recommendations. In the absence of high‐quality evidence, expert consensus and a Delphi study were used to formulate recommendations. We highlight key areas of awake tracheal intubation in which specific recommendations were made, which included: indications; procedural setup; checklists; oxygenation; airway topicalisation; sedation; verification of tracheal tube position; complications; management of unsuccessful awake tracheal intubation; post‐tracheal intubation management; consent; and training. We recognise that there are a range of techniques and regimens that may be effective and one such example technique is included. Breaking down the key practical elements of awake tracheal intubation into sedation, topicalisation, oxygenation and performance might help practitioners to plan, perform and address complications. These guidelines aim to support clinical practice and help lower the threshold for performing awake tracheal intubation when indicated.

New finding What is the central question of this study? Transition to supine posture induces an inspiratory load associated with cortical activation in awake healthy subjects. Some obstructive sleep apnoea patients exhibit this cortical activity in the sitting position contributing to the arousal-dependent compensation of their upper airway abnormalities. Does a transition to the supine posture in awake obstructive sleep apnoea patients increase this cortical activity? What is the main finding and its importance? The transition to supine posture induces a reduction in the cortical activity despite evidence of an increase in genioglossus activity, suggesting that genioglossus activation is not driven by cortical activity. Abstract The anatomy and mechanical properties of the upper airway (UA) depend on posture. Lying in a supine position causes cephalad fluid shift to the neck, thus narrowing the UA and predisposing the individual to obstructive sleep apnoea (OSA). Increased UA dilator muscle activity during wakefulness prevents the UA collapse but the underlying mechanism has not yet been elucidated. In the sitting position during wakefulness, some OSA patients exhibit preinspiratory cortical activity (preinspiratory potential, PIP) probably related to UA abnormalities. The aim of this study was to investigate changes in the preinspiratory cortical activity and UA dilator muscle in OSA patients during postural challenge. An electroencephalogram was used to detect PIP, and the genioglossus electromyographic activity and ventilation were analysed in 17 awake, male OSA patients while they were sitting, just after lying down, and then in response to leg positive pressure to enhance cephalad fluid shift. The prevalence of PIP decreased from 53% (sitting) to 12% (supine) (P = 0.002) in association with increased genioglossus activity (tonic from median (25th, 75th centiles) 2.3 (1.8, 2.8)% to 3.6 (1.7, 5.0)% of voluntary deglutition, P = 0.019; phasic from 2.3 (1.9, 2.8)% to 3.7 (2.0, 6.1)%, P = 0.024), and with increased transcutaneous carbon dioxide pressure (from 43.0 (42.4, 44.2) to 44.6 (43.5, 45.2) mmHg). No change was observed during leg-positive-pressure application. Moving from the sitting position to the supine position reduces respiratory-related premotor cortical activity in awake OSA patients. The concomitant increase in genioglossus activity, therefore, is not driven by cortical respiratory activity.

Aims The brain function that detects deviations in the acoustic environment can be evaluated with mismatch negativity (MMN). MMN to sound duration deviance has recently drawn attention as a biomarker for schizophrenia. Nonhuman animals, including rats, also exhibit MMN‐like potentials. Therefore, MMN research in nonhuman animals can help to clarify the neural mechanisms underlying MMN production. However, results from preclinical MMN studies on duration deviance have been conflicting. We investigated the effect of sound frequency on MMN‐like potentials to duration deviance in rats. Methods Event‐related potentials were recorded from an electrode placed on the primary auditory cortex of free‐moving rats using an oddball paradigm consisting of 50‐ms duration tones (standards) and 150‐ms duration tones (deviants) at a 500‐ms stimulus onset asynchrony. The sound frequency was set to three conditions: 3, 12, and 50 kHz. Results MMN‐like potentials that depended on the short‐term stimulus history of background regularity were only observed in the 12‐kHz tone frequency condition. Conclusions MMN‐like potentials to duration deviance are subject to tone frequency of the oddball paradigm in rats, suggesting that rats have distinct sound duration recognition ability., We investigated the effect of sound frequency on mismatch negativity (MMN)‐like potentials to duration deviance in rats. The sound frequency was set to three conditions: 3, 12, and 50 kHz. As a result, MMN‐like potentials that depended on the short‐term stimulus history of background regularity were only observed in the 12‐kHz tone frequency condition.

Sleepy drivers have problems with keeping the vehicle within the lines, and might often need to apply a sudden or hard corrective steering wheel movement. Such movements, if they occur while driving on a slippery road, might increase the risk of ending off road due to the unforgiving nature of slippery roads. We tested this hypothesis. Twelve young men participated in a driving simulator experiment with two counterbalanced conditions; dry versus slippery road x day (alert) versus night (sleepy) driving. The participants drove 52.5 km on a monotonous two-lane highway and rated their sleepiness seven times using the Karolinska Sleepiness Scale. Blink durations were extracted from an electrooculogram. The standard deviation of lateral position and the smoothness of steering events were measures of driving performance. Each outcome variable was analysed with mixed-effect models with road condition, time-of-day and time-on-task as predictors. The Karolinska Sleepiness Scale increased with time-on-task (p < 0.001) and was higher during night drives (p < 0.001), with a three-way interaction suggesting a small increased sleepiness with driving time at night with slippery road conditions (p = 0.012). Blink durations increased with time-on-task (p < 0.01) with an interaction between time-of-day and road condition (p = 0.040) such that physiological sleepiness was lower for sleep-deprived participants in demanding road conditions. The standard deviation of lateral position increased with time-on-task (p = 0.026); however, during night driving it was lower on a slippery road (p = 0.025). The results indicate that driving in demanding road condition (i.e. slippery road) might further exhaust already sleepy drivers, although this is not clearly reflected in driving performance.

As many other facets of life-biological, behavioral, psychological, cognitive, and social-undergo change during adolescence, so too does sleep. The context of sleep behavior is modified by alterations to underlying bioregulatory processes that challenge sleep's timing, regularity, and quantity. The buildup of sleep pressure during the day gets slower, opening the door for youth to stay awake later; however, the amount of sleep required does not diminish. Further, the circadian timing system delays, again providing the biological impetus for later sleep. When these changes meet societal demands for early wake, most teens cannot find a way to get enough sleep at a consistent time from night to night. Insufficient and irregular sleep provides a fragile foundation to support mental health.

OBJECTIVE To compare awake endoscopy with Muller's maneuver (MM) during both sitting and supine positions, with drug-induced sleep endoscopy (DISE) as regard determination of different levels, patterns, and degrees of collapse of the upper airway in adult patients with obstructive sleep apnea (OSA). METHODS The study included adult patients with OSA symptoms, who had apnea hypopnea index (AHI) > 15. Patients were examined by MM in a sitting position, then during supine position; DISE then followed. Site, pattern, and degree of obstruction were assessed by experienced examiners according to the nose oropharynx hypopharynx and larynx classification. RESULTS Eighty-one adult subjects were included. The most common pattern of collapse at the retro-palatal level was the concentric pattern, while the predominant pattern at the hypopharyngeal level was the lateral wall collapse. The analysis of the pattern of collapse of the study group revealed that the individual pattern did not change (for the same patient at the same level) in the majority of patients whatever the maneuver or the position. CONCLUSION This study demonstrates the feasibility of positional awake endoscopy for providing valuable surgical information as regard level, pattern, and degree of severity in OSA. The data of positional awake endoscopy were comparable to those gained from DISE with less morbidity and costs. The idea and results of this work provide a useful foundation for future research in this area. Multicenter studies are encouraged to obtain more reliable conclusions and more clear standards aiming at a better surgical planning. LEVEL OF EVIDENCE 4 Laryngoscope, 130:2269-2274, 2020.

Awake tracheal intubation has a high success rate and a favourable safety profile but is underused in cases of anticipated difficult airway management. These guidelines are a comprehensive document to support decision making, preparation and practical performance of awake tracheal intubation. We performed a systematic review of the literature seeking all of the available evidence for each element of awake tracheal intubation in order to make recommendations. In the absence of high-quality evidence, expert consensus and a Delphi study were used to formulate recommendations. We highlight key areas of awake tracheal intubation in which specific recommendations were made, which included: indications; procedural setup; checklists; oxygenation; airway topicalisation; sedation; verification of tracheal tube position; complications; management of unsuccessful awake tracheal intubation; post-tracheal intubation management; consent; and training. We recognise that there are a range of techniques and regimens that may be effective and one such example technique is included. Breaking down the key practical elements of awake tracheal intubation into sedation, topicalisation, oxygenation and performance might help practitioners to plan, perform and address complications. These guidelines aim to support clinical practice and help lower the threshold for performing awake tracheal intubation when indicated.