Movements after Captive Bolt Stunning in Cattle and Possible Animal- and Process-Related Impact Factors-A Field Study

Movements in cattle after captive bolt stunning cause problems in the slaughter process and lead to uncertainties in assessing stunning effectiveness. The objective of this study was to categorize and quantify these movements and determine animal- and process-related impact factors, as well as connections to stunning effectiveness and shooting position. In total 2911 cows, heifers, and bulls (dairy, beef, and crossbreeds) were examined (mean age 3.02 years). Movements from landing until at least four minutes after sticking were recorded by action cams (Apeman® A100). Nine movement categories were defined ("kicking hind limb", "twitching", "bending and stretching hind limb", "lifting and bending forelimb", "body arching laterally", "body arching ventrally", and "arching backwards"). According to the movement severity, a score was assigned to each category. The scores were summed, either for certain process intervals, e.g., LANDING (ejection from the stunning box), HOISTING, or STICKING, or for the total time between LANDING and end of the FOURTH MINUTE OF BLEEDING (sum score). Statistical analysis (ANOVA) was performed on the scores. Only 6.6% of cattle showed no movement. Most movements occurred during STICKING and FIRST MINUTE OF BLEEDING, occurring rarely up to 8 min after sticking. While cows moved most at LANDING, bulls and heifers moved more if all process intervals were considered. The sum score was highest in German Angus, Charolais, and Limousin and lowest in Brown Swiss and Simmental. The score at LANDING was highest in German Angus and Black Holstein. The use of pneumatic stunners and an increase in bolt-exit length significantly reduced movements. No impact of stunning effectiveness on movements was found, but only 19 cattle showed reduced effectiveness.

Unconsciousness as the main nonfocal symptom of anterior circulation transient ischemic attack: A case report

RATIONALE

Unconsciousness is a nonfocal symptom of transient ischemic attack (TIA) that is frequently observed in patients with vertebrobasilar artery stenosis or occlusion. Conversely, loss of consciousness due to anterior circulation involvement (e.g., middle cerebral artery [MCA]) is a rare occurrence in TIA.

PATIENT CONCERNS

This report describes a rare case in a 59-year-old woman who experienced recurrent episodes of altered consciousness because of the occlusion or stenosis of her MCAs.

DIAGNOSES

The diagnosis of the case was updated from TIA to acute cerebral infarction, finally. Following initial loss of consciousness, cranial magnetic resonance imaging (MRI) did not reveal any evidence of acute cerebral infarction. However, following the second and third episodes of unconsciousness, the MRI revealed multiple new acute cerebral infarcts affecting both the cerebral hemispheres. Further evaluation through digital subtraction angiography disclosed complete occlusion of the left MCA and severe stenosis of the right MCA.

INTERVENTIONS

Early in her illness, the patient was treated with vasodilators, aspirin and atorvastatin. Finally, 2 stents in her right and left MCAs were placed respectively, followed by treatment with aspirin, clopidogrel, and double-dosed atorvastatin calcium. Meanwhile, the patient focused on avoiding conditions which may lead to dehydration in her daily life routine.

OUTCOMES

The episodes of unconsciousness of this patient were completely resolved. During the 1-year postoperative follow-up, the patient remained clinically stable without any symptoms of unconsciousness, limb numbness or weakness, or dizziness.

LESSONS

These findings suggested that hypoperfusion in the bilateral cerebral hemispheres played a pivotal role in precipitating the patient episodes of unconsciousness. This case underscores the possibility that occlusion or severe stenosis in both MCAs can contribute to recurrent episodes of unconsciousness due to hypoperfusion. Moreover, it emphasizes the association between these episodes of unconsciousness and an increased risk of subsequent ischemic stroke.

One node among many: sevoflurane-induced hypnosis and the challenge of an integrative network-level view of anaesthetic action

Building on their known ability to influence sleep and arousal, Li and colleagues show that modulating the activity of glutamatergic pedunculopontine tegmental neurones also alters sevoflurane-induced hypnosis. This finding adds support for the shared sleep-anaesthesia circuit hypothesis. However, the expanding recognition of many neuronal clusters capable of modulating anaesthetic hypnosis raises the question of how disparate and anatomically distant sites ultimately interact to coordinate global changes in the state of the brain. Understanding how these individual sites work in concert to disrupt cognition and behaviour is the next challenge for anaesthetic mechanisms research.

Alternatives to Carbon Dioxide in Two Phases for the Improvement of Broiler Chickens' Welfare during Stunning

This study evaluated the exposure to gas mixtures of carbon dioxide (CO2) associated with nitrogen (N2) as alternatives to CO2 in two phases to improve the welfare of broiler chickens at slaughter. Broilers were exposed to one of three treatments: 40C90C (1st phase: <40% CO2 for 2 min; 2nd phase: >90% CO2 and <2% O2 for 2 min, n = 92), 40C60N (40% CO2, 60% N2, and <2% O2 for 4 min, n = 79), or 20C80N (20% CO2, 80% N2, and <2% O2 for 4 min, n = 72). Brain activity (EEG) was assessed to determine the onset of loss of consciousness (LOC) and death. Behavioural assessment allowed for characterisation of an aversive response to the treatments and confirmed loss of posture (LOP) and motionlessness as behavioural proxies of LOC and brain death in 40C60N and 20N80C. However, the lack of quality of the EEG traces obtained in 40C90C did not allow us to determine the onset of LOC and brain death for this treatment. The onset of LOC in 40C60N was found at 19 s [14-30 s] and in 20C80N at 21 s [16-37 s], whereas a LOP was seen at 53 s [26-156 s] in 40C90C. Birds showed brain death in 40C60N at 64 s [43-108 s] and in 20C80N at 70 s [45-88 s]), while they became motionless in 40C90C at 177 s [89-212 s]. The 40C90C birds not only experienced more events of aversive behaviours related to mucosal irritation, dyspnoea, and breathlessness during induction to unconsciousness but were at risk of remaining conscious when the CO2 concentration was increased in the 2nd phase (known to cause severe pain). From an animal welfare point of view, 40C60N proved to be the least aversive of the three treatments tested, followed by 20C80N and 40C90C.

A case report of near-missed heat stroke

RATIONALE

Heat-related illnesses have protean manifestations that can mimic other life-threatening conditions. The diagnosis of heat stroke requires a high index of suspicion if the patient has been exposed to a high-temperature environment. Central nervous system dysfunction is a cardinal feature. Strict adherence to temperature criteria can potentially lead to misdiagnosis.

PATIENT CONCERNS

A 37-year-old construction worker was brought in by his wife and coworker due to a sudden loss of consciousness while resting after completing his work.

DIAGNOSES

Due to challenges faced during the coronavirus disease 2019 pandemic, as well as language barriers, a detailed history from the coworker who witnessed the patient's altered sensorium was not available. He was initially suspected of having encephalitis and brainstem stroke. However, subsequent investigations revealed multiorgan dysfunction with a normal brain computed tomography and cerebral computed tomography angiogram. In view of the multiple risk factors for heat stroke, pupillary constriction, and urine color suggestive of rhabdomyolysis, a diagnosis of heat stroke was made.

INTERVENTIONS

Despite delayed diagnosis, the patient's multiorgan dysfunction recovered within days with basic supportive care.

OUTCOMES

There were no noticeable complications on follow-up 14 months later.

LESSONS

Heat stroke can be easily confused with other neurological pathologies, particularly if no history can be obtained from the patient or informant. When approaching a comatose patient, we propose that serum creatinine kinase should be considered as an initial biochemical screening test.

Loss of free will in the Iranian criminal justice system: Interdisciplinary analysis of law and neuroscience

Today, with the development of neuroscience and the discovery of new secrets of the brain, the social sciences, including law, have made significant progress with the help of new findings in this science. One of the significant applications of neuroscience in modern criminal law is the explanation of the neurological dimensions of human free will, which in addition to creating a profound and scientific approach to the definition of this important element of criminal responsibility, can help ascertain the loss of free will causes. To this end, the present study is an attempt to answer this question in the context of the Iranian criminal justice system: What are the core causes of the loss of free will from the perspective of neurolaw? The paper strives to take an appropriate step toward the development of criminal justice. In this study, we found that mental disorders, coercion, drunkenness, somnambulism, and error are the core causes that can be assessed in particular ways using EEG and fMRI techniques, however, each with limitations.

Acute Fatty Liver of Pregnancy Complicated With Mild Encephalitis/Encephalopathy With a Reversible Splenial Lesion: A Case Report

Acute fatty liver of pregnancy (AFLP) is a rare complication of pregnancy that may result in fulminant hepatic failure. A 28-year-old woman, at 36 weeks of gestation, presented to a maternal-fetal outpatient clinic with fever and headache. She was prescribed analgesics and was planned for follow-up. Two days later, she was taken back for evaluation by her husband to the previous physician again because of the subacute onset of impaired consciousness. Blood tests showed a marked elevation of liver enzymes and C-reactive protein (CRP), and the patient was transported to a tertiary hospital. A clinical diagnosis of AFLP or hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome was made, and an emergency cesarean section was performed. Unconsciousness was prolonged due to mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) for three days. A liver biopsy was performed on postoperative day 11. Liver biopsy results showed large and small droplet fatty deposits, and the diagnosis of AFLP was confirmed. Thereafter, the elevated liver enzymes resolved spontaneously solely by supportive care. The patient presented with symptoms of impaired consciousness due to mild encephalitis/encephalopathy with a reversible splenial lesion (MERS), which led to a visit to a tertiary hospital and early intervention for AFLP. This case suggested that there may be similarities between the two pathologies of AFLP and MERS.

Stunning Compliance in Halal Slaughter: A Review of Current Scientific Knowledge

Muslim scholars are not unanimous on the issue of the application of stunning in the halal slaughtering of animals. Appropriate stunning makes animals unconscious instantaneously, thus avoiding unnecessary pain and stress during the slaughtering of animals. The present review comprehensively summarizes the available scientific literature on stunning methods in view of their halal compliance during the slaughter of animals. The issue of maximum blood loss, reversibility of consciousness, and animals remaining alive during the halal cut are the key determinants of approval of stunning in the halal slaughter. Further, missed stuns due to poor maintenance of equipment, improper applications, and poor restraining necessitates additional stunning attempts, which further aggravates pain and stress in animals. Scientific findings suggest that halal-compliant stunning technologies are reversible, do not kill animals prior to the halal cut, and do not obstruct blood loss. There is a need to carry out further research on the refinement of available stunning technologies and their application, proper restraints, proper identification of the death status of animals, and assurance of animal welfare in commercial halal meat production.

Evaluation of a commercial electrical stunning method for farmed grower saltwater crocodiles (Crocodylus porosus) using non-invasive EEG measurements

The aim of this study was to assess welfare outcomes of electrical stunning as a means of restraint in farmed grower saltwater crocodiles (Crocodylus porosus). Physical handling of a stunned, unconscious crocodile is far safer for the operator than handling a fully conscious animal. Electroencephalogram (EEG) was recorded before and after the application of electrical stunning at 50 Hz or 400 Hz using an electrical stunner applied to the cranial plate (Position 1: P1-50 Hz; n = 31, P1-400 Hz; n = 29) or immediately behind the skull (Position 2: P2-50 Hz; n = 29; P2-400 Hz; n = 30). For all electrical stuns, percentage total EEG power in a 10-s epoch decreased in the alpha and beta frequency bands; and increased in the delta and lower frequencies bands. All electrical stuns resulted in increased strength of signal, based on the quadratic mean EEG power in all frequency bands of the EEG. Greatest change in power occurred in the delta frequency band, with P1-50 Hz. This was greater than with P2-50 Hz; while decibel change using 400 Hz at either position was intermediate and not significantly different from either. Application of either electrical stunner at position 1 resulted in seizure-like activity and activation in low frequencies, but at position 2 this was not consistent across all animals. The ability of the electrical stunning equipment to consistently induce recoverable unconsciousness could be ranked in decreasing order as: P1-50 Hz > P1-400 Hz = P2-50 Hz > P2-400 Hz. Based on behavioural observations, all animals in the study appeared to stunned however evaluation of duration of EEG changes indicates that use of the electrical stunning equipment at 50 Hz would allow some margin for inaccuracies in tong placement, while achieving a consistently reliable stun.

I focus only when I see your fear-fearful faces are not prioritized by attention when processed outside of awareness

The defensive reaction to threats consists of two components: non-specific physiological arousal and specific attentional prioritization of the threatening stimulus, both of which are assumed by the so-called "low-road" hypothesis to be induced automatically and unconsciously. Although ample evidence indicates that non-specific arousal can indeed be caused by unconscious threatening stimuli, data regarding the involvement of the attentional selection mechanism remain inconclusive. Therefore, in the present study we used ERPs to compare the potential engagement of attention in the perception of subliminal and supraliminal fearful facial expressions to that of neutral ones. In the conscious condition, fearful faces were preferentially encoded (as indicated by the N170 component) and prioritized by bottom-up (EPN) and spatial attention (N2pc) in an automatic, task-independent manner. Furthermore, consciously perceived fearful expressions engaged cognitive resources (SPCN, P3) when face stimuli were task-relevant. In the unconscious condition, fearful faces were still preferentially encoded (N170), but we found no evidence for any type of attentional prioritization. Therefore, by showing that threatening stimuli engage attention only when perceived consciously, our findings challenge the "low road" hypothesis and point to the limits of unconscious attentional selection.

Pre-Slaughter Stunning of Farmed Atlantic Halibut in CO2-Saturated Seawater: Assessment of Unconsciousness by Electroencephalography (EEG)

As fish welfare becomes a growing concern, it is important to ensure humane treatment during slaughter. This study aimed to assess the onset of unconsciousness in Atlantic halibut immersed in CO₂-saturated seawater through electroencephalography (EEG). Of the 29 fish studied, 10 exhibited escape attempts, indicating aversion to CO₂-saturated water despite its oxygenation. EEG signals showed four distinct phases: transitional, excitation (high amplitude-high frequency), suppressed, and iso-electric phases. The onset of the suppressed phase, indicative of unconsciousness, occurred on average 258.8 ± 46.2 s after immersion. The spectral analysis of the EEG signals showed a progressive decrease in median frequency, spectral edge frequency, and high frequency contribution, which corresponded to the gradual loss of consciousness. The study concludes that CO₂-saturated water is not recommended for pre-slaughter handling of halibut due to the extended time required for the onset of unconsciousness and the observed aversive behaviour. Ensuring humane treatment during slaughter is important for addressing public concern and safeguarding fish welfare in all stages of production.

P2X7 Receptor in microglia contributes to propofol-induced unconsciousness by regulating synaptic plasticity in mice

Propofol infusion is processed through the wake-sleep cycle in neural connections, and the ionotropic purine type 2X7 receptor (P2X7R) is a nonspecific cation channel implicated in sleep regulation and synaptic plasticity through its regulation of electric activity in the brain. Here, we explored the potential roles of P2X7R of microglia in propofol-induced unconsciousness. Propofol induced loss of the righting reflex in male C57BL/6 wild-type mice and increased spectral power of the slow wave and delta wave of the medial prefrontal cortex (mPFC), all of which were reversed with P2X7R antagonist A-740003 and strengthened with P2X7R agonist Bz-ATP. Propofol increased the P2X7R expression level and P2X7R immunoreactivity with microglia in the mPFC, induced mild synaptic injury and increased GABA release in the mPFC, and these changes were less severe when treated with A-740003 and were more obvious when treated with Bz-ATP. Electrophysiological approaches showed that propofol induced a decreased frequency of sEPSCs and an increased frequency of sIPSCs, A-740003 decrease frequency of sEPSCs and sIPSCs and Bz-ATP increase frequency of sEPSCs and sIPSCs under propofol anesthesia. These findings indicated that P2X7R in microglia regulates synaptic plasticity and may contribute to propofol-mediated unconsciousness.

Patients with Disorders of Consciousness: Are They Nonconscious, Unconscious, or Subconscious? Expanding the Discussion

Unprecedented advancements in the diagnosis and treatment of patients with disorders of consciousness (DoC) have given rise to ethical questions about how to recognize and respect autonomy and a sense of agency of the personhood when those capacities are themselves disordered, as they typically are in patients with DoC. At the intersection of these questions rests the distinction between consciousness and unconsciousness. Indeed, evaluations of consciousness levels and capacity for recovery have a significant impact on decisions regarding whether to discontinue or prolong life-sustaining therapy for DoC patients. However, in the unconsciousness domain, there is the confusing array of terms that are regularly used interchangeably, making it quite challenging to comprehend what unconsciousness is and how it might be empirically grounded. In this opinion paper, we will provide a brief overview of the state of the field of unconsciousness and show how a rapidly evolving electroencephalogram (EEG) neuroimaging technique may offer empirical, theoretical, and practical tools to approach unconsciousness and to improve our ability to distinguish consciousness from unconsciousness and also nonconsciousness with greater precision, particularly in cases that are borderline (as is typical in patients with DoC). Furthermore, we will provide a clear description of three distant notions of (un)consciousness (unconsciousness, nonconsciousness, and subconsciousness) and discuss how they relate to the experiential selfhood which is essential for comprehending the moral significance of what makes life worth living.

The Feasibility of Animal-Based Indicators of Consciousness and Unconsciousness for Stunning in Sheep: A Systematic Review

BACKGROUND

According to EU legislation, animal-based indicators (ABMs) are used to evaluate the efficacy of stunning methods to ensure that animals do not regain consciousness. EFSA has provided a list of ABMs for electrical and mechanical stunning in sheep; however, there is still a lack of information on their feasibility. We aimed to identify and evaluate the feasibility constraints of ABMs commonly applied in slaughterhouses to assess proper stunning in sheep.

METHOD

For this systematic review, we searched the Scopus and Web of Science databases from 2000 to 8 August 2022, including full peer-reviewed papers written in English on the welfare of sheep at the stunning and restraint phases. We excluded studies using a gas stunning method or without prior stunning, as well as manuscripts in which indicators were applied after sticking.

RESULTS

Of 1289 records identified, only 8 papers were eligible for the critical evaluation of physical aspects that affect the feasibility of ABMs. These aspects were defined as a given definition of the feasibility of ABMs, and information was summarized and critically evaluated. The results highlighted a lack of information on the feasibility of ABMs which should be considered in the various conditions of commercial slaughterhouses.

Case studies in physiology: is blackout in breath-hold diving related to cardiac arrhythmias?

Syncope or "blackout" (BO) in breath-hold diving (freediving) is generally considered to be caused by hypoxia. However, it has been suggested that cardiac arrhythmias affecting the pumping effectivity could contribute to BO. BO is fairly common in competitive freediving, where athletes aim for maximal performance. We recorded heart rate (HR) during a static apnea (STA) competition, to reveal if arrhythmias occur. Four male freedivers with STA personal best (PB) of 349±43s, volunteered during national championships, where they performed STA floating face down in a shallow indoor pool. A non-coded Polar T31 chest strap recorded R-R intervals and a water- and pressure proof pulse oximeter arterial oxygen saturation. Three divers produced STA near their PB without problems, while one diver ended with BO at 5min17s, which was 12s beyond his PB. He was immediately brought up by safety divers and resumed breathing within 10s. All divers attained similar lowest diving HR (47±4bpm), but HR recordings displayed a different pattern for the diver ending with BO. After a short tachycardia the three successful divers developed bradycardia which became more pronounced during the second half of the apnea. The fourth diver developed pronounced bradycardia earlier, and at 2.5min into the apnea HR started alternating between approximately 50 and 140 bpm, until the diver lost consciousness. At resumed breathing, HR returned to baseline. Nadir oxygen saturation was similar for all divers. We speculate that arrhythmia could have contributed to BO, by lowering stroke volume leading to a systolic blood pressure drop, affecting brain perfusion.

Lipid emulsion-induced recovery from unconsciousness caused by lidocaine toxicity: A case report

Lipid emulsion is used to treat systemic toxicity caused by local anesthetics. In addition, lipid emulsion was reported to be effective in ameliorating cardiovascular depression evoked by non-local anesthetic drug toxicity with high lipid solubility. A 47-year-old woman underwent local anesthetic infiltration with 40 mL of 2% lidocaine (20 and 20 mL) to remove a mass in the upper back. After operation, she experienced convulsions and loss of consciousness due to lidocaine toxicity. Midazolam followed by lipid emulsion was administered to treat central nervous system symptoms including unconsciousness and decreased Glasgow Coma Scale. The patient recovered from unconsciousness and presented improved Glasgow Coma Scale after lipid emulsion administration, and then fully recovered from local anesthetic systemic toxicity. This case suggests that early lipid emulsion treatment, before further progression of local anesthetic systemic toxicity, provides an enhanced recovery from unconsciousness and decreased Glasgow Coma Scale due to lidocaine toxicity.

Assessing Cognitive Outcomes in Coma Survivors: A Literature Review

(1) Background: Although cognitive impairments in coma survivors are common, methods of measuring long-term cognitive outcomes in this population are inconsistent, precluding the development of a strong evidence-base to support clinical decision making. In this literature review, we identify and characterize the measures used to track cognitive recovery in coma survivors to data. (2) Methods: We extracted the instrument used for cognitive assessment, the cognitive domains assessed, methods administration and scoring, and timing of assessment from 134 of 996 screened records. (3) Results: A total of 133 unique cognitive tests and cognitive testing batteries were identified, with 97 cognitive instruments used in less than three articles. The instruments assessed 20 different cognitive domains, with 73 articles also using tests that assess general "cognitive ability". Cognitive instruments ranged from subjective assessments to comprehensive cognitive batteries. There were inconsistent points of reference for the timing of assessment across studies, with few studies repeating assessments at more than one time point, and arbitrary time intervals between tests. (4) Conclusions: Overall, this review illustrates the enormous disparity between studies that track cognitive outcome in coma survivors, and the need for a systematic, patient-accessible method of assessing cognitive functioning in future studies with this population.

Theta phase coherence in visual mismatch responses involved in access processing to visual awareness

Introduction: The electroencephalographic brain response to a deviation from the preceding sequential regularity of visual events, called visual mismatch negativity (vMMN), is well known to reflect automatic visual change detection. Our preliminary study showed a significant correlation between the enhancement of the vMMN amplitude and facilitation of perceptual alternation in binocular rivalry when the deviant stimulus was presented unconsciously. This implies that the vMMN is relevant to access processing, in which the unconscious stimulus is consciously perceived. Recent studies have reported that theta band oscillation evoked by a deviant stimulus is involved in evoking vMMN. However, it has not been clarified whether theta band oscillation associated with vMMN is also relevant to access processing. Methods: We analyzed the correlations between event-related spectral perturbation (ERSP) and inter-trial phase coherence (ITPC) in the theta band and the proportion of perceptual alternation from before to after the presentation of deviation in the same experimental paradigm as in our previous study. Results: We found that an increase in ITPC in the theta band tended to correlate with facilitation of perceptual alternation in binocular rivalry when the deviant was presented unconsciously, but there was no significant correlation in ERSP. Discussion: The results suggest that theta phase coherence underlying the visual mismatch process is relevant to the access processing.

s-ketamine enhances thalamocortical and corticocortical synaptic transmission in acute murine brain slices via increased AMPA-receptor-mediated pathways

Despite ongoing research efforts and routine clinical use, the neuronal mechanisms underlying the anesthesia-induced loss of consciousness are still under debate. Unlike most anesthetics, ketamine increases thalamic and cortical activity. Ketamine is considered to act via a NMDA-receptor antagonism-mediated reduction of inhibition, i.e., disinhibition. Intact interactions between the thalamus and cortex constitute a prerequisite for the maintenance of consciousness and are thus a promising target for anesthetics to induce loss of consciousness. In this study, we aim to characterize the influence of s-ketamine on the thalamocortical network using acute brain-slice preparation. We performed whole-cell patch-clamp recordings from pyramidal neurons in cortical lamina IV and thalamocortical relay neurons in acute brain slices from CB57BL/6N mice. Excitatory postsynaptic potentials (EPSPs) were obtained via electrical stimulation of the cortex with a bipolar electrode that was positioned to lamina II/III (electrically induced EPSPs, eEPSPs) or via optogenetic activation of thalamocortical relay neurons (optogenetically induced EPSPs, oEPSPs). Intrinsic neuronal properties (like resting membrane potential, membrane threshold for action potential generation, input resistance, and tonic action potential frequency), as well as NMDA-receptor-dependent and independent spontaneous GABA_A-receptor-mediated inhibitory postsynaptic currents (sIPSCs) were evaluated. Wilcoxon signed-rank test (level of significance < 0.05) served as a statistical test and Cohen's U3_1 was used to determine the actual effect size. Within 20 min, s-ketamine (5 μM) significantly increased both intracortical eEPSPs as well as thalamocortical oEPSPs. NMDA-receptor-mediated intracortical eEPSPs were significantly reduced. Intrinsic neuronal properties of cortical pyramidal neurons from lamina IV and thalamocortical relay neurons in the ventrobasal thalamic complex were not substantially affected. Neither a significant effect on NMDA-receptor-dependent GABA_A sIPSCs (thought to underly a disinhibitory effect) nor a reduction of NMDA-receptor independent GABA_A sIPSCs was observed. Both thalamocortical and intracortical AMPA-receptor-mediated EPSPs were significantly increased.In conclusion, our findings show no evidence for a NMDA-receptor antagonism-based disinhibition, but rather suggest an enhanced thalamocortical and intracortical synaptic transmission, which appears to be driven via increased AMPA-receptor-mediated transmission.

Deterministic and Stochastic Components of Cortical Down States: Dynamics and Modulation

Slow oscillations are an emergent activity of the cerebral cortex network consisting of alternating periods of activity (Up states) and silence (Down states). Up states are periods of persistent cortical activity that share properties with that of underlying wakefulness. However, the occurrence of Down states is almost invariably associated with unconsciousness, both in animal models and clinical studies. Down states have been attributed relevant functions, such as being a resetting mechanism or breaking causal interactions between cortical areas. But what do Down states consist of? Here, we explored in detail the network dynamics (e.g., synchronization and phase) during these silent periods in vivo (male mice), in vitro (ferrets, either sex), and in silico, investigating various experimental conditions that modulate them: anesthesia levels, excitability (electric fields), and excitation/inhibition balance. We identified metastability as two complementary phases composing such quiescence states: a highly synchronized "deterministic" period followed by a low-synchronization "stochastic" period. The balance between these two phases determines the dynamical properties of the resulting rhythm, as well as the responsiveness to incoming inputs or refractoriness. We propose detailed Up and Down state cycle dynamics that bridge cortical properties emerging at the mesoscale with their underlying mechanisms at the microscale, providing a key to understanding unconscious states.SIGNIFICANCE STATEMENT The cerebral cortex expresses slow oscillations consisting of Up (active) and Down (silent) states. Such activity emerges not only in slow wave sleep, but also under anesthesia and in brain lesions. Down states functionally disconnect the network, and are associated with unconsciousness. Based on a large collection of data, novel data analysis approaches and computational modeling, we thoroughly investigate the nature of Down states. We identify two phases: a highly synchronized "deterministic" period, followed by a low-synchronization "stochastic" period. The balance between these two phases determines the dynamic properties of the resulting rhythm and responsiveness to incoming inputs. This finding reconciles different theories of slow rhythm generation and provides clues about how the brain switches from conscious to unconscious brain states.

Propofol anesthesia concentration rather than abrupt behavioral unresponsiveness linearly degrades responses in the rat primary auditory cortex

Despite extensive knowledge of its molecular and cellular effects, how anesthesia affects sensory processing remains poorly understood. In particular, it remains unclear whether anesthesia modestly or robustly degrades activity in primary sensory regions, and whether such changes are linked to anesthesia drug concentration versus behavioral unresponsiveness, which are typically confounded. Here, we used slow gradual intravenous propofol anesthesia induction together with auditory stimulation and intermittent assessment of behavioral responsiveness while recording epidural electroencephalogram, and neuronal spiking activity in primary auditory cortex (PAC) of eight rats. We found that all main components of neuronal activity including spontaneous firing rates, onset response magnitudes, onset response latencies, postonset neuronal silence duration, late-locking to 40 Hz click-trains, and offset responses, gradually changed in a dose-dependent manner with increasing anesthesia levels without showing abrupt shifts around loss of righting reflex or other time-points. Thus, the dominant factor affecting PAC responses is the anesthesia drug concentration rather than any sudden, dichotomous behavioral state changes. Our findings explain a wide array of seemingly conflicting results in the literature that, depending on the precise definition of wakefulness (vigilant vs. drowsy) and anesthesia (light vs. deep/surgical), report a spectrum of effects in primary regions ranging from minimal to dramatic differences.

A Comparison of Brain-State Dynamics across Common Anesthetic Agents in Male Sprague-Dawley Rats

Anesthesia is a powerful tool in neuroscientific research, especially in sleep research where it has the experimental advantage of allowing surgical interventions that are ethically problematic in natural sleep. Yet, while it is well documented that different anesthetic agents produce a variety of brain states, and consequently have differential effects on a multitude of neurophysiological factors, these outcomes vary based on dosages, the animal species used, and the pharmacological mechanisms specific to each anesthetic agent. Thus, our aim was to conduct a controlled comparison of spontaneous electrophysiological dynamics at a surgical plane of anesthesia under six common research anesthetics using a ubiquitous animal model, the Sprague-Dawley rat. From this direct comparison, we also evaluated which anesthetic agents may serve as pharmacological proxies for the electrophysiological features and dynamics of unconscious states such as sleep and coma. We found that at a surgical plane, pentobarbital, isoflurane and propofol all produced a continuous pattern of burst-suppression activity, which is a neurophysiological state characteristically observed during coma. In contrast, ketamine-xylazine produced synchronized, slow-oscillatory activity, similar to that observed during slow-wave sleep. Notably, both urethane and chloral hydrate produced the spontaneous, cyclical alternations between forebrain activation (REM-like) and deactivation (non-REM-like) that are similar to those observed during natural sleep. Thus, choice of anesthesia, in conjunction with continuous brain state monitoring, are critical considerations in order to avoid brain-state confounds when conducting neurophysiological experiments.

The Right Inferior Frontal Gyrus Plays an Important Role in Unconscious Information Processing: Activation Likelihood Estimation Analysis Based on Functional Magnetic Resonance Imaging

Unconsciousness is a kind of brain activity that occurs below the level of consciousness, and the masked priming paradigm is a classic paradigm to study unconscious perceptual processing. With the deepening of unconscious perception research, different researchers mostly use different experimental materials and different masked priming paradigms in a single experiment but not for the comprehensive analysis of the unconscious information processing mechanism itself. Thus, the purpose of this study is to conduct a comprehensive analysis through a cross-experimental paradigm, cross-experimental materials, and cross-experimental purposes. We used activation likelihood estimation to test functional magnetic resonance imaging studies, involving 361 subjects, 124 foci in eight studies representing direct comparison of unconscious processing with baseline, and 115 foci in 10 studies representing direct comparison of unconscious priming effects. In the comparison of unconscious processing and baseline, clusters formed in the left superior parietal gyrus, the right insular gyrus, and the right inferior frontal gyrus (IFG) triangular part after correcting for familywise error (FWE). In the comparison of priming effects, clusters formed in only the right IFG triangular part after correcting for FWE. Here, we found that ventral and dorsal pathways jointly regulate unconscious perceptual processes, but only the ventral pathway is involved in the regulation of unconscious priming effects. The IFG triangular part is involved in the regulation of unconscious perceptual processing and unconscious priming effects and may be an important brain area in unconscious information processing. These preliminary data provide conditions for further study of the neural correlation of unconscious information processing.

Neural Substrates for Regulation of Sleep and General Anesthesia

General anesthesia has been successfully used in clinics for over 170 years, but its mechanisms of effect remain unclear. Behaviorally, general anesthesia is similar to sleep as it produces a reversible transition between wakefulness and the state of being unaware of one’s surroundings. A discussion regarding the common circuits of sleep and general anesthesia has been ongoing as an increasing number of sleep-arousal regulatory nuclei are reported to participate in the consciousness shift occurring during general anesthesia. Recently, with progress in research technology, both positive and negative evidence for overlapping neural circuits between sleep and general anesthesia has emerged. This article provides a review of the latest evidence on the neural substrates for sleep and general anesthesia regulation by comparing the roles of pivotal nuclei in sleep and anesthesia.

Resuscitation of an Unconscious Victim of Accidental Hypothermia in 1805

In 1805, W.D., a 16-y-old boy, became hypothermic after he was left alone on a grounded boat in Leith Harbour, near Edinburgh, Scotland. He was brought to his own house and resuscitated with warm blankets, smelling salts, and massage by Dr. George Kellie. W.D. made an uneventful recovery. We discuss the pathophysiology and treatment of accidental hypothermia, contrasting treatment in 1805 with treatment today. W.D. was hypothermic when found by passersby. Although he appeared dead, he was rewarmed with help from Dr. Kellie and his assistants over 200 y ago using simple methods. One concept that has not changed is the critical importance of attempting resuscitation, even if it seems to be futile. Don't give up!

Self-Face Activates the Dopamine Reward Pathway without Awareness

The self-face advantage has been demonstrated not only at the supraliminal level, but also at the subliminal level. However, it remains unclear whether subliminal self-face processing involves the same neural networks as those for supraliminal self-face processing. Here, we show that the ventral tegmental area, a center of the dopamine reward pathway, exhibited greater activation to subliminal presentations of the self-face than those of the others’ faces, whereas subliminal presentations of the others’ faces induced activation in the amygdala, which generally responds to unfamiliar information. This self-other difference in brain response was consistently observed even when the facial configuration was modified without changing the shape of the facial parts. The present findings suggest that the dopamine reward pathway is involved in automatic self-advantage in face processing, and the subliminal self-other facial discrimination does not depend on information of the precise facial configuration.

Caring for an Unconscious Transgender Patient at the End of Life: Ethical Considerations and Implications

Individuals who identify as transgender (trans) or other gender-diverse identities are highly marginalized populations within the United States health care system. Transgender individuals experience a broad range of health disparities leading to devastating health outcomes. Experiences with discrimination and biased care often result in a lack of trust in providers and reduced care seeking, yet providers frequently rely on communication with trans patients to build competence. Consequently, when a trans patient has restricted communication, whether due to biological or psychological reasons, their care can be further disrupted. The nursing code of ethics compels the provision of competent care to all patients, regardless of demographics or gender identity, including individuals with serious illness and injury. This article describes an approach to the provision of affirmative, trans-inclusive care in a palliative nursing context that integrates cultural humility and self-reflection into an established patient care framework. The approach is then applied to identify ethical dilemmas present in the case of a trans patient who arrived at a hospital in an unconscious state following serious injury. Nurses' use of the ethical approach when caring for seriously ill trans patients would represent important progress toward fostering a health care system that provides affirmative, trans-inclusive care.

The efficacy of three on-farm euthanasia methods for broiler chickens throughout the production cycle

1. There is a need to humanely kill moribund or injured broiler birds on-farm with no reasonable chance of recovery. Two experiments evaluated the efficacy of three commercially applicable killing methods; manual cervical dislocation (CD), mechanical cervical dislocation with the Koechner Euthanising Device (KED) and a non-penetrative captive bolt device (Zephyr-EXL; ZEXL), at 7, 21 or 35 d of age, on their ability to induce insensibility (unconsciousness and loss of brain stem reflexes) and death.2. Experiment one assessed the damage to the cranial-cervical region resulting from the methods applied to cadavers of cull birds (n = 180) by radiography and gross pathology observation.3. Experiment two evaluated the latency to insensibility and death when cull broiler birds (n = 240) were killed by CD, KED or ZEXL, using behavioural and reflexive indicators. Insensibility and death were measured by the absence of pupillary light, palpebral blink and nictitating membrane reflexes and cessation of rhythmic breathing, cloacal winking and convulsions. Analysis of variance for the main effect of the method was performed to determine the differences.4. In experiment one, only the Zephyr resulted in skull fractures. A higher number of vertebral fractures occurred with KED application compared to CD, at 21 and 35 d.5. In experiment two, indicators of sensibility were absent earliest with the ZEXL (μ < 2 s); then,CD (μ = 28 s) and were longest with KED (μ = 47 s), at 21 and 35 d. Cloacal winking and convulsions ceased earlier after CD (88 s), compared to either KED (124 s) or Zephyr (118 s). Death after a single application occurred 100%, 100% and 98% of time for CD, KED and ZEXL, respectively.6. Overall, all methods were efficacious at inducing insensibility and death. Insensibility occurred earliest with ZEXL, whilst death occurred earliest with CD. KED resulted in the longest time to insensibility and death.

A conscious choice: Is it ethical to aim for unconsciousness at the end of life?

One of the most commonly referenced ethical principles when it comes to the management of dying patients is the doctrine of double effect (DDE). The DDE affirms that it is acceptable to cause side effects (e.g. respiratory depression) as a consequence of symptom-focused treatment. Much discussion of the ethics of end of life care focuses on the question of whether actions (or omissions) would hasten (or cause) death, and whether that is permissible. However, there is a separate question about the permissibility of hastening or causing unconsciousness in dying patients. Some authors have argued that the DDE would not permit end of life care that directly aims to render the patient unconscious. The claim is that consciousness is an objective human good and therefore doctors should not intentionally (and permanently) suppress it. Three types of end of life care (EOLC) practices will be explored in this article. The first is symptom-based management (e.g. analgesia); the second is proportional terminal sedation as a means of relieving suffering (also referred to as palliative sedation or continuous deep sedation); and finally, deliberate and rapid sedation to unconsciousness until death (a practice we call terminal anaesthesia in this paper). After examining the common arguments for the various types of symptom-based management and sedation, we apply the DDE to the latter two types of EOLC practices. We argue that aiming at unconsciousness, contrary to some claims, can be morally good or at least morally neutral in some dying patients.

Comparison of anaesthetic- and seizure-induced states of unconsciousness: a narrative review

In order to understand general anaesthesia and certain seizures, a fundamental understanding of the neurobiology of unconsciousness is needed. This review article explores similarities in neuronal and network changes during general anaesthesia and seizure-induced unconsciousness. Both seizures and anaesthetics cause disruption in similar anatomical structures that presumably lead to impaired consciousness. Despite differences in behaviour and mechanisms, both of these conditions are associated with disruption of the functionality of subcortical structures that mediate neuronal activity in the frontoparietal cortex. These areas are all likely to be involved in maintaining normal consciousness. An assessment of the similarities in the brain network disruptions with certain seizures and general anaesthesia might provide fresh insights into the mechanisms of the alterations of consciousness seen in these particular unconscious states, allowing for innovative therapies for seizures and the development of anaesthetic approaches targeting specific networks.

Isoflurane Potentiation of GABAA Receptors Is Reduced but Not Eliminated by the β3(N265M) Mutation

Background: Mice carrying the GABA_A receptor β3(N265M) point mutation, which renders receptors incorporating β3-subunits insensitive to many general anesthetics, have been used experimentally to link modulation of different receptor subtypes to distinct behavioral endpoints. Remarkably, however, the effect of the mutation on the susceptibility to modulation by isoflurane (a standard reference agent for inhalational vapors) has never been tested directly. Therefore, we compared the modulation by isoflurane of expressed α5β3(N265M)γ2L receptors with their wild type counterparts. Methods: Using whole-cell electrophysiological recording and rapid solution exchange techniques, we tested the effects of isoflurane at concentrations ranging from 80 μM to 320 μM on currents activated by 1 μM GABA. We measured drug modulation of wild-type α5β3γ2L GABA_A receptors and their counterparts harboring the β3(N265M) mutation. Results: Currents elicited by GABA were enhanced two- to four-fold by isoflurane, in a concentration-dependent manner. Under the same conditions, receptors incorporating the β3(N265M) mutation were enhanced by approximately 1.5- to two-fold; i.e., modulation by isoflurane was attenuated by approximately one-half. Direct activation by isoflurane was also present in mutant receptors but also attenuated. Conclusions: In contrast to the complete insensitivity of β3(N265M) mutant receptors to etomidate and propofol, the mutation has only a partial effect on receptor modulation by isoflurane. Therefore, the persistence of isoflurane effects in mutant mice does not exclude a possible contribution of β3-GABA_A receptors.

Brain Oscillatory Activity during Tactile Stimulation Correlates with Cortical Thickness of Intact Areas and Predicts Outcome in Post-Traumatic Comatose Patients

In this study, we have reported a correlation between structural brain changes and electroencephalography (EEG) in response to tactile stimulation in ten comatose patients after severe traumatic brain injury (TBI). Structural morphometry showed a decrease in whole-brain cortical thickness, cortical gray matter volume, and subcortical structures in ten comatose patients compared to fifteen healthy controls. The observed decrease in gray matter volume indicated brain atrophy in coma patients induced by TBI. In resting-state EEG, the power of slow-wave activity was significantly higher (2–6 Hz), and the power of alpha and beta rhythms was lower in coma patients than in controls. During tactile stimulation, coma patients’ theta rhythm power significantly decreased compared to that in the resting state. This decrease was not observed in the control group and correlated positively with better coma outcome and the volume of whole-brain gray matter, the right putamen, and the insula. It correlated negatively with the volume of damaged brain tissue. During tactile stimulation, an increase in beta rhythm power correlated with the thickness of patients’ somatosensory cortex. Our results showed that slow-wave desynchronization, as a nonspecific response to tactile stimulation, may serve as a sensitive index of coma outcome and morphometric changes after brain injury.

Are common delirium assessment tools appropriate for evaluating delirium at the end of life in cancer patients?

OBJECTIVES

The objectives of this study are to investigate how many advanced cancer patients became unconscious or non-communicative after pharmacological treatment for delirium, and to explore whether existing delirium assessment tools can successfully evaluate its severity at the end of life.

METHODS

This was a secondary analysis of a registry study that examined the efficacy and safety of antipsychotics for advanced cancer patients with delirium. A total of 818 patients were recruited from 39 specialized palliative care services in Japan. The severity of delirium was measured using the Richmond Agitation-Sedation Scale-Palliative care version, the Delirium Rating Scale-Revised-98 (DRS-R-98), and the Nursing Delirium Screening Scale (Nu-DESC) on Day 3. Data from 302 patients with motor anxiety with an Agitation Distress Scale score ≥2 on Day 0 were analyzed for this study. The patients were categorized into four treatment response groups: complete response (CR: no agitation and fully communicative), partial response (PR: no/mild agitation and partially communicative), unconscious/non-communicative (UC), and no change (NC).

RESULTS

On Day 3, 29 (10%; 95% confidence intervals [CI], 7-13) and 2 (1%; 95% CI, 0-2) patients became unconscious and non-communicative, respectively. Forty-four patients were categorized as CR, 97 as PR, 31 as UC, and 96 as NC. The scores of the DRS-R-98 and Nu-DESC in the UC group were rated higher than patients in the NC group were.

CONCLUSIONS

A considerable number of cancer patients with delirium became unconscious or non-communicative. Existing delirium assessment tools may be inappropriate for measuring the severity of delirium in end-of-life.

Neural signatures of α2-Adrenergic agonist-induced unconsciousness and awakening by antagonist

How the brain dynamics change during anesthetic-induced altered states of consciousness is not completely understood. The α2-adrenergic agonists are unique. They generate unconsciousness selectively through α2-adrenergic receptors and related circuits. We studied intracortical neuronal dynamics during transitions of loss of consciousness (LOC) with the α2-adrenergic agonist dexmedetomidine and return of consciousness (ROC) in a functionally interconnecting somatosensory and ventral premotor network in non-human primates. LOC, ROC and full task performance recovery were all associated with distinct neural changes. The early recovery demonstrated characteristic intermediate dynamics distinguished by sustained high spindle activities. Awakening by the α2-adrenergic antagonist completely eliminated this intermediate state and instantaneously restored awake dynamics and the top task performance while the anesthetic was still being infused. The results suggest that instantaneous functional recovery is possible following anesthetic-induced unconsciousness and the intermediate recovery state is not a necessary path for the brain recovery.

The Dream Catcher experiment: blinded analyses failed to detect markers of dreaming consciousness in EEG spectral power

The Dream Catcher test defines the criteria for a genuine discovery of the neural constituents of phenomenal consciousness. Passing the test implies that some patterns of purely brain-based data directly correspond to the subjective features of phenomenal experience, which would help to bridge the explanatory gap between consciousness and brain. Here, we conducted the Dream Catcher test for the first time in a step-wise and simplified form, capturing its core idea. The Dream Catcher experiment involved a Data Team, which measured participants' brain activity during sleep and collected dream reports, and a blinded Analysis Team, which was challenged to predict, based solely on brain measurements, whether or not a participant had a dream experience. Using a serial-awakening paradigm, the Data Team prepared 54 1-min polysomnograms of non-rapid eye movement sleep-27 of dreamful sleep and 27 of dreamless sleep (three of each condition from each of the nine participants)-redacting from them all associated participant and dream information. The Analysis Team attempted to classify each recording as either dreamless or dreamful using an unsupervised machine learning classifier, based on hypothesis-driven, extracted features of electroencephalography (EEG) spectral power and electrode location. The procedure was repeated over five iterations with a gradual removal of blindness. At no level of blindness did the Analysis Team perform significantly better than chance, suggesting that EEG spectral power could not be utilized to detect signatures specific to phenomenal consciousness in these data. This study marks the first step towards realizing the Dream Catcher test in practice.

Demystifying White Matter Injury in the Unconscious Patients with Diffusion Tensor Imaging

Background

Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) provide a noninvasive window to study the neural connectivity and reconstruct the tracts. Detection of white matter injury (WMI) by DTT is a recent application being used in stroke, diffuse axonal injury, and neurodegenerative disorders. Fiber tracking in patients with brain hemorrhage can detect loss of fibers and anatomical disruption of the tracts, which can be useful in the prognostication of patient outcome.

Materials and Methods

DTI and fiber tracking was done in four patients admitted at Fujita Health University Banbuntane Hospital, Japan, with decreased consciousness following brain hemorrhage (3 patients with aneurysmal subarachnoid hemorrhage and one patient with bifrontal hemorrhage), and WMI was analyzed. We also reviewed the literature on tractography in patients with brain hemorrhage and its correlation with consciousness.

Results

We found significant frontal WMI in the form of thinning and anatomical disruption in all four cases. The frontal white matter tracts form an important component of the limbic system and ascending reticular activating system and frontal WMI correlated with the poor conscious level and cognitive dysfunction. Structural damage to the fiber tracts demonstrated as thinning, reduction in the volume or absence on tractography with corresponding reduction in the mean fractional anisotropy values in the frontal white matter of the affected side.

Conclusion

DTI can be useful as a critical tool for revealing the anatomical basis for the cognitive dysfunction and unconsciousness and can be possibly used to prognosticate patient recovery. Early detection of WMI by DTI can also help in tailored rehabilitation. The authors believe that DTT could have a crucial role in the future for detecting structural changes which lead to cognitive dysfunction and further studies are needed to arrive at a specific protocol for detecting WMI.

Prediction of Body Weight of a Person Lying on a Smart Mat in Nonrestraint and Unconsciousness Conditions

We want to predict body weight while lying in bed for an elderly patient who is unable to move by himself/herself. To this end, we have implemented a prototype system that estimates the body weight of a person lying on a smart mat in nonrestraint and unconsciousness conditions. A total of 128 FSR (force sensing resistor) sensors were placed in a 16 × 8-grid structure on the smart mat. We formulated three methods based on the features to be applied: segmentation, average cumulative sum of pressure, and serialization. All the proposed methods were implemented with four different machine-learning models: regression, deep neural network (DNN), convolutional neural network (CNN), and random forest. We compared their performance using MAE and RMSE as evaluation criteria. From the experimental results, we chose the serialization method with the DNN model as the best model. Despite the limitations of the presence of dead space due to the wide spacing between the sensors and the small dataset, the MAE and the RMSE of the body weight prediction of the proposed method was 4.608 and 5.796, respectively. That is, it showed an average error of ±4.6 kg for the average weight of 72.9 kg.

Teaching Glasgow Coma Scale Assessment by Videos: A Prospective Interventional Study among Surgical Residents

Objective  Glasgow Coma Scale (GCS) assessment is vital for the management of various neurological, neurosurgical, and critical care disorders. Learning GCS scoring needs good training and practice. Due to limitation of teachers, the new entrants of the clinical team find it difficult to learn and use it correctly. Training through videos is being increasingly utilized in the medical field. This study aimed to evaluate the efficiency of video teaching of GCS scoring among general surgery residents. Materials and Methods  A prospective study was done utilizing the freely available video at glasgowcomascale.org. The participants (general surgery residents, 1st-3rd year) were asked to assess and record their responses related to GCS both before and after watching the video. A blinded neurosurgeon recorded the correct responses separately. Statistical Analysis  The difference between correct responses of the residents before and after watching the video was calculated using the "chi-square test." p -Value ≤ 0.05 was taken as significant. Results  There was a significant improvement in GCS scoring by residents after watching the videos ( p < 0.05). On estimating the responses separately, all the three responses (eye, verbal, and motor) improved significantly for 1st-year residents while only the motor response improved significantly for 2nd- and 3rd-year residents. The mode subjective improvement for the 1st-, 2nd-, and 3rd-year residents was 5, 4, and 3, respectively. Conclusion  Training GCS scoring through videos is an effective way of teaching the surgery residents with maximum benefit to the junior-most ones.

Socioneuroscience and its contributions to conscious versus unconscious volition and control. The case of gender violence prevention

Research in neuroscience is being very fruitful in providing evidence about the influence of social experience in the architecture and functioning of the brain. In so doing, neuroscience is posing new and fascinating research questions to examine in depth the social processes that produce those neural changes. To undertake the task of tackling such research questions, evidence from the social sciences are necessary to better understand how different types of social experiences produce different types of synaptic changes and even modify subcortical brain structures differently. It will be the dialogue between neuroscience, other natural sciences and the social sciences which will advance the scientific understanding of plastic changes in the brain which result from complex social experiences that have been traditionally studied by the social sciences. Socioneuroscience constitutes the arena for such interdisciplinary dialogue and research that can both advance the scientific understanding of the human brain and provide evidence-based solutions to most urgent social problems. Socioneuroscience studies the relations between the human brain and social interactions taking into account knowledge from all social sciences and the natural sciences. Processes of conscious versus unconscious social volition and control is one central area of inquiry in socioneuroscience. In this article, we discuss the dominant coercive discourse in society -which presents males with aggressive attitudes and behaviors as more attractive- as an example of social control of human volition which imprisons many individuals' sexual freedom. However, due to brain plasticity, certain experiences that question such dominant discourse and empty violence from attractiveness open up the possibility for the individual and the society to break free from the neural wiring imposed by the dominant coercive discourse and, in the words of Santiago Ramón y Cajal, be ourselves “the architects of our brain”, contributing to overcome violence against women.

Anesthetics: from modes of action to unconsciousness and neurotoxicity

Modern anesthetic compounds and advanced monitoring tools have revolutionized the field of medicine, allowing for complex surgical procedures to occur safely and effectively. Faster induction times and quicker recovery periods of current anesthetic agents have also helped reduce health care costs significantly. Moreover, extensive research has allowed for a better understanding of anesthetic modes of action, thus facilitating the development of more effective and safer compounds. Notwithstanding the realization that anesthetics are a prerequisite to all surgical procedures, evidence is emerging to support the notion that exposure of the developing brain to certain anesthetics may impact future brain development and function. Whereas the data in support of this postulate from human studies is equivocal, the vast majority of animal research strongly suggests that anesthetics are indeed cytotoxic at multiple brain structure and function levels. In this review, we first highlight various modes of anesthetic action and then debate the evidence of harm from both basic science and clinical studies perspectives. We present evidence from animal and human studies vis-à-vis the possible detrimental effects of anesthetic agents on both the young developing and the elderly aging brain while discussing potential ways to mitigate these effects. We hope that this review will, on the one hand, invoke debate vis-à-vis the evidence of anesthetic harm in young children and the elderly, and on the other hand, incentivize the search for better and less toxic anesthetic compounds.

Should we include monitors to improve assessment of awareness and pain in unconscious palliatively sedated patients? A case report

BACKGROUND

Awareness and pain during palliative sedation is typically assessed by observational scales, but the use of such scales has been put into question.

CASE PRESENTATION

A woman in her mid-80s was admitted to a palliative care unit, presenting with chronic lymphatic leukemia, depression, and a cerebrovascular accident, with right-sided hemiplegia and aphasia. The patient was unable to eat and was suffering from nausea and vomiting. Before admission, the patient had expressed her desire to discontinue treatment on several occasions.

CASE MANAGEMENT

The decision was made to initiate palliative sedation. The patient consented to take part in a study to assess level of comfort and pain using two monitoring devices (NeuroSense monitor and Analgesia Nociception Index monitor).

CASE OUTCOME

The patient died 90 h after initiation of palliative sedation. Titration of the medication was challenging and sedation was not deep enough during the first 2 days. Thirteen assessments made with the Ramsay Sedation Scale showed that the patient was considered to be in a deep sleep, while in fact the NeuroSense monitor indicated otherwise.

CONCLUSION

This case demonstrates the feasibility and potential advantages of using monitoring devices to objectify assessments of pain and discomfort in palliatively sedated patients.

Association between Syncope and Tumarkin Attacks in Ménière's Disease

OBJECTIVES

The aim of the current study was to further collect evidence that would confirm the hypothesis that vestibular drop attacks (VDAs) could cause syncope in patients with Ménière's disease (MD).

MATERIALS AND METHODS

A cross-sectional survey design was employed in the present study. An Internet-based survey was administered on 602 individuals with MD. The mean age of the participants was 56.7 (25-75) years, and the mean duration of the disease was 12.4 (0.5-35) years.

RESULTS

VDAs with varying severity were present among 307 (50.7%) patients and led to fall in 92 patients, and syncope occurred in 45 patients with VDA. The overall percentage of syncope due to MD was 4.7%. Factors, such as duration of disease, age, and gender of the patient, did not explain attacks of syncope. Migraine and headache were not associated with syncope. Syncope was witnessed in 23 and self-reported by 22 patients. Syncope was associated with frequent VDA, duration of VDA, and falls that occurred during VDA. Patients with syncope reported the experience as frightening, had reduced general health-related quality of life, had higher anxiousness scores, and suffered more from fatigue. They also experienced problems with work, employment, and social restrictions.

CONCLUSION

Approximately 5% of patients with MD suffer from syncope, and syncope occurs among patients with VDA. In vestibular syncope, the sympathetic tone is lost, and baroreflex feedback is inhibited leading to fall and syncope. The consequences of vestibular syncope are severe, and patients face injuries and a significantly reduced quality of life.

The arousal effect of hyperbaric oxygen through orexin/hypocretin an upregulation on ketamine/ethanol-induced unconsciousness in male rats

Approaches that facilitate the recovery from coma would have enormous impacts on patient outcomes and medical economics. Orexin-producing neurons release orexins (also known as hypocretins) energy-dependently to maintain arousal. Hyperbaric oxygen (HBO) could increase ATP levels by preserving mitochondrial function. We investigated, for the first time, the arousal effects of HBO and orexins mechanisms in a rat model of unconsciousness induced by ketamine or ethanol. A total of 120 Sprague-Dawley male rats were used in this study. Unconsciousness was induced either by intraperitoneal injection of ketamine or ethanol. The HBO treatment (100% O2 at 3 ATA) was administered immediately after unconsciousness induction for 1 hr. SB334867, orexin-1 receptor (OX1R) inhibitor, or JNJ10397049, orexin-2 receptor (OX2R) inhibitor was administered 30 min intraperitoneally before unconsciousness induction. Loss of righting reflex test (LORR) and Garcia test were used to evaluate the unconsciousness duration and neurological deficits after recovering from unconsciousness, respectively. Enzyme-linked immunosorbent assay was used to measure brain tissue ATP and orexin A levels. Ketamine or ethanol injection resulted in LORR immediately and neurological deficits 6 hr after unconsciousness induction. HBO treatment significantly reduced the LORR duration, improved Garcia scores and unregulated ATP and orexin A levels in the brain tissue. Administration of OX1R inhibitor or OX2 R inhibitor abolished arousal and neurological benefits of HBO. In conclusion, HBO exerted arousal-promoting effects on unconscious rats induced by ketamine or ethanol. The underlying mechanism was via, at least in part, ATP/orexin A upregulation. HBO may be a practical clinical approach to accelerate unconsciousness recovery in patients.

Disruption of cortical network activity by the general anaesthetic isoflurane

Background

Actions of general anaesthetics on activity in the cortico-thalamic network likely contribute to loss of consciousness and disconnection from the environment. Previously, we showed that the general anaesthetic isoflurane preferentially suppresses cortically evoked synaptic responses compared with thalamically evoked synaptic responses, but how this differential sensitivity translates into changes in network activity is unclear.

Methods

We investigated isoflurane disruption of spontaneous and stimulus-induced cortical network activity using multichannel recordings in murine auditory thalamo-cortical brain slices.

Results

Under control conditions, afferent stimulation elicited short latency, presumably monosynaptically driven, spiking responses, as well as long latency network bursts that propagated horizontally through the cortex. Isoflurane (0.05-0.6 mM) suppressed spiking activity overall, but had a far greater effect on network bursts than on early spiking responses. At isoflurane concentrations >0.3 mM, network bursts were almost entirely blocked, even with increased stimulation intensity and in response to paired (thalamo-cortical + cortical layer 1) stimulation, while early spiking responses were <50% blocked. Isoflurane increased the threshold for eliciting bursts, decreased their propagation speed and prevented layer 1 afferents from facilitating burst induction by thalamo-cortical afferents.

Conclusions

Disruption of horizontal activity spread and of layer 1 facilitation of thalamo-cortical responses likely contribute to the mechanism by which suppression of cortical feedback connections disrupts sensory awareness under anaesthesia.

The essential neurological examination of the unconscious patient in the emergency room

OBJECTIVE

To determine whether neurologists with long-term experience in the emergency room are in general agreement about the essential components of the neurological examination (NE) used on unconscious patients in whom an obvious cause for coma is lacking.

METHODS

We surveyed 31 board-certified practicing neurologists who regularly examine unconscious patients in the emergency room and asked them to list the specific components of the NE that they would normally choose to apply in at least 80% of cases.

RESULTS

Twenty-seven neurologists rated 24 of 38 items as essential steps of the neurological examination of the unconscious patient, with a high level of agreement amongst survey participants.

CONCLUSIONS

There was a high degree of consensus amongst the neurologists surveyed about which steps are essential for the NE of the unconscious patient. These findings provide an important source of validation for teaching this particular NE to medical students, as well as nonneurologists working in an emergency setting.

Psychogenic coma after dental surgery under general anaesthesia

Delayed awakening after general anaesthesia due to psychogenic coma is a phenomenon that rarely presents to the oral and maxillofacial surgeon. A case of psychogenic coma following general anaesthesia for dental extractions is presented here. It is recommended that patients at risk of conversion disorder should be counselled about the risks of psychogenic coma. Early diagnosis of this condition could lead to better patient management.

The Rational Unconscious: Implications for Mental Illness and Psychotherapy

Rational and reality-congruent unconscious processes facilitate adaptive functioning and have implications for mental illness and psychotherapy. With this knowledge, psychotherapists can more effectively guide interventions to improve mental health.