State Of Unresponsiveness Research Articles

Persistent Hiccups Following Thalamic Hemorrhage (P2-5.014)

<h3>Objective:</h3> N/A <h3>Background:</h3> Persistent hiccups (lasting more than 48 hours) can cause physical and emotional distress. They can result in dehydration, exhaustion, malnutrition, insomnia, wound dehiscence, ventilatory desynchronization and hemodynamic changes. Hiccups are thought to be due to a complex reflex arc involving peripheral nerves and central structures such as the brainstem, temporal lobe, basal ganglia, hypothalamus and the spinal cord levels C3–5. Medullary strokes, for instance, have been reported to cause hiccups. We report a patient with a thalamic bleed who developed persistent hiccups. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> A 56-year-old man was brought to the hospital in an unresponsive state. He was intubated for airway protection. CT brain showed a left thalamic hemorrhage with edema and mass effect on the 3^rd ventricle, intraventricular extension of hemorrhage and hydrocephalus. External ventricular drain was placed successfully with adequate drainage. One week after admission, patient developed persistent abdominal jerks. These jerks were occurring every 3–4 seconds and would last for hours with brief periods of remission. He was started on levetiracetam 1000 mg IV bid and then increased to 1500 mg IV BID without any improvement of symptoms. The patient was also placed on video EEG which did not reveal any epileptiform abnormality but did show an EMG artifact. His electrolytes including sodium, potassium and corrected calcium levels were normal. He did not have any evidence of pneumonia or other infections. It was determined that these jerks were likely hiccups. Metoclopramide 10 mg IV was tried without any benefit. He was then started on Baclofen 10 mg PO TID which resulted in a significant improvement in hiccups. <h3>Conclusions:</h3> Our case suggests that thalamic lesions might also lead to persistent hiccups. <b>Disclosure:</b> Dr. Nemade has nothing to disclose. Dr. Shivkumar has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Teva. Dr. Shivkumar has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Sunovion. Dr. Dhingra has nothing to disclose.

Abstract WP140: Coma As A Presentation For Large Vessel Occlusion Stroke

Introduction: Coma is an unresponsive state of disordered consciousness characterized by impaired arousal and awareness. While coma has been studied in the context of traumatic brain injury, the epidemiology and pathophysiology of coma in ischemic stroke has been underexplored. We sought to characterize the incidence and clinical features of coma as a presentation of large vessel occlusion (LVO) stroke. Methods: Individuals who presented with LVO were identified from July 2018 to December 2020. Coma was defined as an unresponsive state of impaired arousal and awareness, operationalized as a score of 3 on NIHSS item 1a: responds only with reflex motor or autonomic effects or totally unresponsive, flaccid, and areflexic. Results: A total of 28/638 (4.4%) patients with large vessel occlusion stroke were identified as presenting with coma. The median age was 65 (IQR 48-78), and 57% were female. The median NIHSS was 32 (IQR 29-34). Occlusion locations included basilar (10), vertebral (2), P1 posterior cerebral (2), internal carotid (4), M1 middle cerebral (6), and M2 middle cerebral arteries (4). In all 14 patients with anterior LVO, the acute LVO was unilateral. Of these 14, 6 had evidence of acute or chronic stroke involving the contralateral hemisphere; 1 experienced seizure; 1 experienced cardiac arrest; and 1 had chronic occlusion of the contralateral ICA. Overall, 20/28 died during the admission. Of those who died, 9 presented with anterior LVO and 11 with posterior LVO. Eight patients were treated with EVT. For those not treated, reasons included established infarct with ASPECTS &lt;6 (11), delayed presentation (2), pre-stroke disability and goals of care (3), and absence of intracranial proximal occlusion on repeat imaging (2). Conclusions: It is not uncommon for patients with LVO stroke to present with coma, and 65% of patients not treated with EVT had delayed presentations or large established infarcts, emphasizing the need for maintaining a high index of suspicion. While more commonly thought to result from posterior LVO, coma in our cohort was similarly likely to result from anterior LVO. Further study of these patients may shed light on the pathophysiology of coma. Efforts to improve early diagnosis and care are crucial given their poor outcomes.

MR Neuroimaging Findings in Adult Diabetic Patients- Two Case Reports

Diabetes Mellitus (DM) can affect any part of the central and peripheral nervous systems. Significant variations in glucose levels are often symptomatic. Hypoglycaemia as well as hyperglycaemia can present a wide variety of clinical symptoms. Imaging helps by suggesting the correct diagnosis and ensuring early treatment. We hereby present two cases, one of hypoglycaemic encephalopathy and a case of diabetic striatopathy. A 40-year-old female with a 25-year-old history of type 2 diabetes was brought into the emergency room in an unresponsive state since afternoon. The blood glucose was 28 mg/dL, and immediate administration of D 25%x2 stat was done. MRI revealed hyperintensities in the bilateral hippocampi and in the cortex of the bilateral high parietal region on T2WI/FLAIR. Despite intensive medical treatment the patient’s neurologic condition didn’t improve, due to irreversible brain tissue damage, and the patient ultimately died. A 63-year-old male was brought by relatives to causality with complaints of involuntary movements of the right-side of the body since three months, but symptoms have exaggerated since three days. Newly diagnosed DM since three months was on medication T.Metformin 500 mg BD. MRI revealed T1 hyperintensities in posterior half of left putamen. Patient was put on Inj. haloperidol 0.5 mg SOS, T.Aspirin 150 mg OD, T.Atorva 20 mg HS, T.sodium valproate 200 mg BD, T.tetrabenazine 25 mg BD and T.Serenace 0.5 mg BD and patient had improved symptomatically after 15 days of treatment. Imaging can play a crucial role in diagnosis and guide treatment and markedly influence the prognosis of patient.

542: AWAKENING AFTER EXTRACORPOREAL LIFE SUPPORT: ASSESSING AWARENESS IN UNRESPONSIVE WAKEFULNESS

Introduction: Emergence from coma have many stages. Patients enter unresponsive wakefulness (UW) from coma when they open eyes with only reflexive motor responses. The development of voluntary responses to stimuli indicates a minimally conscious state (MCS). The addition of functional communication or object use signifies emergence from MCS. Cognitive motor dissociation has been reported in unresponsive patients with evidence of appropriate brain activation. We present a pediatric case where we detected awareness with bedside electroencephalogram (EEG) and the patient showed eventual emergence from UW. Description: A depressed teenage girl was admitted after suicidal attempt with fluoxetine and lamotrigine ingestion with subsequent cardiopulmonary arrest. After prolonged cardiopulmonary resuscitation, she was cannulated on veno-arterial extracorporeal membrane oxygenation. Initial head computed tomography showed preserved gray-white differentiation. On post-arrest day 5, she was successfully decannulated but remained in an unresponsive wakefulness state. Brain magnetic resonance imaging showed diffuse cerebral microhemorrhages. To assess preserved awareness, we performed protocolized stimulation with EEG. Consistent reactivity with increased frequency and amplitude were observed after both nociceptive and auditory stimulation, with greater response to stimuli from her parent. After slow improvement she emerged from UW on post-arrest day 35 and showed consistent appropriate responses. She was discharged to inpatient rehabilitation on post-arrest day 50. Discussion: Analysis of quantitative EEG data often requires advanced machine learning algorithms that were not readily available to bedside providers. Assessing EEG reactivity with protocolized stimulation is an effective alternative to assess preserved awareness. Our case adds to limited pediatric literature on emergence from coma and detection of preserved awareness early after brain injury. Clinically she was unresponsive to external stimuli but demonstrated signs of arousal to nociceptive and auditory stimuli on EEG, especially when from her parents. Our case demonstrates the feasibility of assessing preserved awareness at bedside via protocolized stimulation with EEG, which may assist in prognosis.

Detecting residual brain networks in disorders of consciousness: A resting-state fNIRS study

Functional near infrared spectroscopy (fNIRS) is an emerging non-invasive technique that allows bedside measurement of blood oxygenation level-dependent hemodynamic signals. We aimed to examine the efficacy of resting-state fNIRS in detecting the residual functional networks in patients with disorders of consciousness (DOC). We performed resting-state fNIRS in 23 DOC patients of whom 12 were in minimally conscious state (MCS) and 11 were in unresponsive wakefulness state (UWS). Ten regions of interest (ROIs) in the prefrontal cortex (PFC) were selected: both sides of Brodmann area (BA) 9, BA10, BA44, BA45, and BA46. Graph-theoretical analysis and seed-based correlation analyses were used to investigate the network topology and the strength of pairwise connections between ROIs and channels. MCS and UWS exhibited varying degrees of the loss of topological architecture, and the regional nodal properties of BA10 were significantly different between them (Nodal degree, PLeft BA10 = 0.01, PRight BA10 < 0.01; nodal efficiency, PLeft BA10 = 0.03, PRight BA10 < 0.01). Compared to healthy controls, UWS had impaired functions in both short- and long-distance connectivity, however, MCS had significantly impaired functions only in long-distance connectivity. The functional connectivity of right BA10 (AUC = 0.88) and the connections between left BA46 and right BA10 (AUC = 0.86) had excellent performance in differentiating MCS and UWS. MCS and UWS have different patterns of topological architecture and short- and long-distance connectivity in PFC. Intraconnections within BA10 and interhemispheric connections between BA10 and 46 are excellent resting-state fNIRS classifiers for distinguishing between MCS and UWS.

Multimodal prediction of residual consciousness in the intensive care unit: the CONNECT-ME study.

Functional MRI (fMRI) and EEG may reveal residual consciousness in patients with disorders of consciousness (DoC), as reflected by a rapidly expanding literature on chronic DoC. However, acute DoC is rarely investigated, although identifying residual consciousness is key to clinical decision-making in the intensive care unit (ICU). Therefore, the objective of the prospective, observational, tertiary center cohort, diagnostic phase IIb study 'Consciousness in neurocritical care cohort study using EEG and fMRI' (CONNECT-ME, NCT02644265) was to assess the accuracy of fMRI and EEG to identify residual consciousness in acute DoC in the ICU. Between April 2016 and November 2020, 87 acute DoC-patients with traumatic or non-traumatic brain injury were examined with repeated clinical assessments, fMRI and EEG. Resting-state EEG and EEG with external stimulations were evaluated by visual analysis, spectral band analysis and a Support Vector Machine (SVM) consciousness classifier. In addition, within- and between-network resting-state connectivity for canonical resting-state fMRI networks were assessed. Next, we used EEG and fMRI data at study enrollment in two different machine-learning algorithms (Random Forest and SVM with a linear kernel), to distinguish patients in a minimally conscious state or better (≥MCS) from those in coma or unresponsive wakefulness state (≤UWS), at time of study enrollment and at ICU-discharge (or before death). Prediction performances were assessed with area under the curve (AUC). Of 87 DoC-patients (mean age, 50.0 ± 18 years, 43% women), 51 (59%) were ≤ UWS and 36 (41%) were ≥ MCS at study enrollment. Thirty-one (36%) patients died in the ICU, including 28 who had life-sustaining therapy withdrawn. EEG and fMRI predicted consciousness levels at study enrollment and ICU-discharge, with maximum AUCs of 0.79 (95% CI 0.77-0.80) and 0.71 (95% CI 0.77-0.80), respectively. Models based on combined EEG and fMRI features predicted consciousness levels at study enrollment and ICU-discharge with maximum AUCs of 0.78 (95% CI 0.71-0.86) and 0.83 (95% CI 0.75-0.89), respectively, with improved positive predictive value and sensitivity. Overall, both machine-learning algorithms (SVM and Random Forest) performed equally well. In conclusion, we suggest that acute DoC prediction models in the ICU be based on a combination of fMRI and EEG features, regardless of the machine-learning algorithm used.

Neuroimaging Findings in CHANTER Syndrome: A Case Series.

Recently, a distinct clinicoradiologic entity involving cerebellar, hippocampal, and basal nuclei transient edema with restricted diffusion (CHANTER) on MR imaging was identified. Patients present in an unresponsive state following exposure to drugs of abuse. Very little information exists regarding this entity, particularly in the radiology literature. We identify and describe 3 patients at our institution with similar clinical and radiographic findings. Multifocal restricted diffusion in the brain is typically associated with poor outcomes. By contrast, CHANTER involves intraventricular obstructive hydrocephalus that, when treated, can lead to substantial recovery. This novel syndrome should be on the differential in patients who present in an unresponsive state after recent opioid use in the context of the above imaging findings. Additional diagnoses on the differential can include ischemic stroke, hypoxic-ischemic encephalopathy, "chasing the dragon," leukoencephalopathy, opioid-associated amnestic syndrome, and pediatric opioid-use-associated neurotoxicity with cerebellar edema.

Tolerance protocol of living kidney transplant for developing countries through basic strategy of lymphocyte depletion.

End-stage kidney failure (ESKD) is a global issue where kidney replacement therapy imposes enormous economic burden to people of developing countries, in addition to the severe limitations to the availability of hemodialysis and peritoneal dialysis technique. The best option of kidney transplantation also requires lifelong combination immunosuppressive medicines, the cost of which is equally comparable to lifelong dialysis. A strategy of achieving transplant tolerance that requires minimum immunosuppressive medicines, although in experimental stage, also requires state-of-art technology with costly medicines and interventions. This is evidently beyond the reach of ESKD patients of developing countries. Hence, globally in developing countries, a need for an innovative but cost-effective tolerance protocol is a burning need for a successful transplant program. In brief, transplant tolerance is defined as a state of donor-specific unresponsiveness to the allograft antigens without the need for ongoing pharmacologic immunosuppression or with a minimal need. Current state-of-art techniques involves: (1) A state of hematological chimera, for complete tolerance; (2) Prope or partial tolerance where immune-reactive T-lymphocytes are inhibited using monoclonal antibodies; and (3) Chimeric antigen receptor for T-regulatory (T-reg) cell therapy using genetically engineered T-reg cells targeting specific T-lymphocyte receptors for inducing anergy. From our real-world experience in transplant management in post-transplant lympho-proliferative disorders (PTLD), we noticed frequently a drastic reduction in the need of immunosuppressive medicines following lympho-ablative therapy for PTLD. We recently published a case study on a real-world experience transplant case where we explained a partial or prope tolerance that developed after lymphocyte ablation therapy, following which the allograft was maintained with low dose dual standard immunosuppressive medicines. Based on this publication, we propose here an innovative tolerance protocol for living related low risk kidney transplantation for developing countries, in this opinion review.

Catatonia; A Case Study and Literature Review

IntroductionCatatonia is a state of apparent unresponsiveness to external stimuli in a person who is awake. More common in patients with unipolar major depression or bipolar disorder. Common signs: immobility, rigidity, mutism, posturing, excessive motor activity, stupor, negativism, staring, and echolalia. We will discuss a case of a 23 year old male with schizophrenia presented with catatonia and decompensation of his schizophrenia in the context of medication non-compliance. We will discuss findings from litrature pertaining to catatonia and treatment strategies.Objectives- To discuss catatonia, its incidence in different psychiatric disorders. - To discuss literature pertaining to catatonia. - To discuss different treatment strategiesMethods- Case studyResults- Signs of catatonia: immobility, mutism, withdrawal and refusal to eat, staring, negativism, posturing, rigidity, waxy flexibility/catalepsy, stereotypy, echolalia, or echopraxia, verbigeration. - Diagnosis: Clinical, Lorazepam challenge. Bush-Francis Catatonia Rating Scale (BFCRS) - BFCR scale is used as the screening tool. If 2 of the 14 are positive, prompts further evaluation and completion of the remaining 9 items. - Differential Diagnosis include; Neuroleptic Malignant Syndrome, Serotoninergic Syndrome, Malignant Hyperthermia, Akinetic Mutism, Delirium, Parkinson’s disease. - Lorazepam can be scheduled at interval doses until the catatonia resolves. - ECT in combination with benzodiazepines is used to treat malignant catatonia. - Possible complications are Physical trauma, malignant catatonia (autonomic instability, life-threatening), dehydration, pneumonia, pressure ulcers due to immobility, muscle contractions, DVT, PEConclusionsPsychiatrists need to be diligent in evaluating patients with Catatonia for other comorbid psychiatric conditions, addressing these conditions and conducting a thorough assessment and prompt treatment.DisclosureNo significant relationships.

Comparison of Testosterone and Prostate-Specific Antigen Nadir Value between Castration Resistant Prostate Cancer and Non-Castration Resistant Prostate Cancer Patients after Androgen Deprivation Therapy - A Single Center Study in Indonesia

BACKGROUND: Prostate cancer is the second most commonly occurring cancer in adult males worldwide. Androgen deprivation therapy (ADT) is the mainstay treatment for patients with advanced prostate cancer. However, despite the low testosterone level (indicative of ADT success), most advanced prostate cancers progress into an androgen unresponsive or castrate resistant state; such cases are defined as castrate-resistant prostate cancer (CRPC) and were associated with worse outcomes and more rapid prostate cancer progression. This study aimed to compare the value of nadir testosterone level and nadir PSA in CRPC and non-CRPC patients who received ADT. AIM: This study was aimed to compare value of nadir testosterone level and nadir PSA in CRPC and non-CRPC patients who received ADT. METHODS: Prostate cancer patients receiving ADT in dr. Hasan Sadikin Bandung General Hospital in September 2018–September 2020 without previous history of CRPC and surgical castration, and prostate cancer with histopathological confirmation were included to the study. The patients prior had received complete blockade ADT with luteinizing hormone agonist (LHRH) goserelin acetate 10.8 mg injected subcutaneously per 3 months and oral anti-androgen bicalutamide 50 mg orally daily. Testosterone and PSA levels were assessed on 1st, 3rd, 6th, and 12th month. Patients then were grouped into CRPC group and non-CRPC group and further subdivided according testosterone levels (&lt;20 and 20–500 ng/dL). Paired t-test and Chi-square test were used to analyze statistical difference (p &lt; 0.05 deemed significant). RESULTS: Significantly higher baseline PSA (p = 0.002) and nadir PSA (p = 0.013) were found on the CRPC group. Nadir testosterone in CRPC group was higher than non-CRPC group but statistically insignificant (p = 0.849). Time to CRPC is faster in nadir testosterone 20–50 ng/dl group than in &lt;20 ng/dl group but statistically insignificant (p = 0.837). CONCLUSION: Prostate cancer patients who had high baseline PSA and nadir PSA after ADT need a longer follow-up time and more frequent testing of the testosterone and PSA values. It can predict the incidence of CRPC and to ensure that prostate cancer patients receive adequate therapy.

Research Highlights

Research Highlights

LPS Guides Distinct Patterns of Training and Tolerance in Mast Cells.

Mast cells (MCs) are tissue-resident, long lived innate immune cells with important effector and immunomodulatory functions. They are equipped with an eclectic variety of receptors that enable them to sense multiple stimuli and to generate specific responses according on the type, strength and duration of the stimulation. Several studies demonstrated that myeloid cells can retain immunological memory of their encounters – a process termed ‘trained immunity’ or ‘innate immune memory’. As MCs are among the one of first cells to come into contact with the external environment, it is possible that such mechanisms of innate immune memory might help shaping their phenotype and effector functions; however, studies on this aspect of MC biology are still scarce. In this manuscript, we investigated the ability of MCs primed with different stimuli to respond to a second stimulation with the same or different ligands, and determined the molecular and epigenetic drivers of these responses. Our results showed that, while the stimulation with IgE and β-glucan failed to induce either tolerant or trained phenotypes, LPS conditioning was able to induce a profound and long-lasting remodeling of the signaling pathways involved in the response against LPS or fungal pathogens. On one side, LPS induced a strong state of unresponsiveness to secondary LPS stimulation due to the impairment of the PI3K-AKT signaling pathway, which resulted in the reduced activation of NF-κB and the decreased release of TNF-α and IL-6, compared to naïve MCs. On the other side, LPS primed MCs showed an increased release of TNF-α upon fungal infection with live Candida albicans, thus suggesting a dual role of LPS in inducing both tolerance and training phenotypes depending on the secondary challenge. Interestingly, the inhibition of HDAC during LPS stimulation partially restored the response of LPS-primed MCs to a secondary challenge with LPS, but failed to revert the increased cytokine production of these cells in response to C. albicans. These data indicate that MCs, as other innate immune cells, can develop innate immune memory, and that different stimulatory environments can shape and direct MC specific responses towards the dampening or the propagation of the local inflammatory response.

Unraveling a Conserved Conformation of the FG Loop upon the Binding of Natural Ligands to the Human and Murine PD1.

The activation of T cells is normally accompanied by inhibitory mechanisms within which the PD1 receptor stands out. PD1 drives T cells to an unresponsive state called exhaustion, characterized by a markedly decreased capacity to exert effector functions upon binding the ligands PDL1 and PDL2. For this reason, PD1 has become one of the most important targets in cancer immunotherapy. Despite the numerous studies about PD1 signaling modulation, how the PD1 signaling pathway is activated upon the ligands' binding remains an open question. In this work, we used molecular dynamics simulations to assess the differences of the PD1 motion in the free state and in complex with the ligands. We found that, in both human and murine systems, the binding of PDL1 and PDL2 stabilizes the conformation of the FG loop similarly. This result, combined with the conservation of the FG loop residues across species, suggests that the conformation of the FG loop is somehow related to the signaling process. We also found a high similarity between the PD1-PDL1 structures with the variable region of an antibody structure, where the FG loop occupies a similar position to the CDR3 light chain.

Future of Solid Organ Transplantation: Organ-Specific Tolerance

A transplant between two people who are not genetically identical is called an allotransplant and the process is called allotransplantation. Donor organs and tissues can be from people who are living, or people who have died because of a significant brain injury or lack of circulation. Allotransplantation can create a rejection process where the immune system of the recipient attacks the foreign donor organ or tissue and destroys it. The recipient may need to take immunosuppressive medication for the rest of their life to reduce the risk of rejection of the donated organ. In general, deliberately induced immunosuppression is performed to prevent the body from rejecting an organ transplant. The adverse effects associated with these agents and the risks of long-term immunosuppression present a number of challenges for the clinician. Immune tolerance, or immunological tolerance, or immunotolerance, is a state of unresponsiveness of the immune system to substances or tissue that have the capacity to elicit an immune response in a given organism.

Looking to relate: observations of a proactive and resilient infant who, with the support of father’s nurturing, helped draw mother out of her unresponsive and disconnected state of mind

ABSTRACT The author describes eleven months of observations of baby Meena, whose mother was unresponsive to and disconnected from her during the first five months of observations after the birth. The observations illustrate the key role and contribution of the baby’s individual temperament in the development of the relationship with the Mother. It is further argued that, in this family, Meena’s father nurtured her and her own proactivity and, critically, her capacity, resilience and motivation assisted in carrying over positive aspects of her relationship with her Father to the relationship with her Mother. This seemed helpful in bringing Mother out of her more cut-off state of mind. Meena and her Mother were able to go on to achieve a reciprocally responsive relationship. These factors also helped Meena not to withdraw or to give up on trying to connect with her mother, as do the infants of unresponsive mothers in the still-face studies [Weinberg, M. K., & Tronick, E. Z. (1996). Infant affective reactions to the resumption of maternal interaction after the still-face. Child Development, 67(3), 905–914. https://doi.org/10.2307/1131869]. The presence of the observer and the extended family’s attribution of intelligence and communicative intent to Meena, even in utero, are seen as part of her ‘facilitating environment’ [Winnicott, D. W. (2018). The maturational processes and the facilitating environment: Studies in the theory of emotional development. Routledge. first published in 1965 by the Hogarth Press and the Institute of Psycho-Analysis.].

Merging Clinical and EEG Biomarkers in an Elastic-Net Regression for Disorder of Consciousness Prognosis Prediction.

Patients with Disorder of Consciousness (DoC) entering Intensive Rehabilitation Units after a severe Acquired Brain Injury have a highly variable evolution of the state of consciousness which is a complex aspect to predict. Besides clinical factors, electroencephalography has clearly shown its potential into the identification of prognostic biomarkers of consciousness recovery. In this retrospective study, with a dataset of 271 patients with DoC, we proposed three different Elastic-Net regressors trained on different datasets to predict the Coma Recovery Scale-Revised value at discharge based on data collected at admission. One dataset was completely EEG-based, one solely clinical data-based and the last was composed by the union of the two. Each model was optimized, validated and tested with a robust nested cross-validation pipeline. The best models resulted in a median absolute test error of 4.54 [IQR = 4.56], 3.39 [IQR = 4.36], 3.16 [IQR = 4.13] for respectively the EEG, clinical and hybrid model. Furthermore, the hybrid model for what concerns overcoming an unresponsive wakefulness state and exiting a DoC results in an AUC of 0.91 and 0.88 respectively. Small but useful improvements are added by the EEG dataset to the clinical model for what concerns overcoming an unresponsive wakefulness state. Data-driven techniques and namely, machine learning models are hereby shown to be capable of supporting the complex decision-making process the practitioners must face.

A novel approach for detection of consciousness level in comatose patients from EEG signals with 1-D convolutional neural network

Coma is an unresponsive state of unconsciousness from which a person cannot be awakened. Glasgow Coma Score (GCS) is a clinical scale for determining the depth and length of a coma. GCS plays an important role in effective and accurate patient evaluation and is critical in planning the right treatment modalities and patient care because it shows patient outcomes and is a measurement performed several times a day. The GCS is universally accepted as a gold standard and validated scale for assessing a patient's level of consciousness. However, the scale's success has been questioned due to variations in interobserver reliability performance. In this study, the data set generated from Electroencephalography (EEG) signals obtained from 39 comatose patients was used in the training of deep neural networks for the classification of consciousness level. The EEG signals were recorded during nurse and family interaction with comatose patients. The level of consciousness was classified with the proposed 1D-CNN model. Consequently, the two classes that we label as low and high consciousness are classified with 83.3% accuracy. To our best knowledge, no prior studies are using 1D-CNN for the classification of EEG-based level of consciousness using the proposed recording process. Our study is unique from other studies in terms of recording procedure and methods.

On no man’s land: Subjective experiences during unresponsive and responsive sedative states induced by four different anesthetic agents

To understand how anesthetics with different molecular mechanisms affect consciousness, we explored subjective experiences recalled after responsive and unresponsive sedation induced with equisedative doses of dexmedetomidine, propofol, sevoflurane, and S-ketamine in healthy male participants (N = 140). The anesthetics were administered in experimental setting using target-controlled infusion or vapouriser for one hour. Interviews conducted after anesthetic administration revealed that 46.9% (n = 46) of arousable participants (n = 98) reported experiences, most frequently dreaming or memory incorporation of the setting. Participants receiving dexmedetomidine reported experiences most often while S-ketamine induced the most multimodal experiences. Responsiveness at the end of anesthetic administration did not affect the prevalence or content of reported experiences. These results demonstrate that subjective experiences during responsive and unresponsive sedation are common and anesthetic agents with different molecular mechanisms of action may have different effects on the prevalence and complexity of the experiences, albeit in the present sample the differences between drugs were minute.

Evaluating reliability through soft error triggered exceptions at ARM Cortex-A9 microprocessor

ARM Cortex-A9 is a high-end microprocessor present in multiple programmable System-on-Chip that is used in many application fields, including those with high reliability requirements. This work aims to understand better the behaviour of a high-end microprocessor in a harsh environment through the analysis, evaluation, and classification of exceptions. Exceptions triggered by radiation effects may end up in an unresponsive state of the microprocessor which is undesirable in high reliability scenarios. Experimental results of both fault injection and irradiation presented in this work provide an extensive analysis of the exceptions and their relationship with the executed code, the usage of operating systems and microprocessor architecture.

Arousal State-Dependence of Interactions Between Short- and Long-Term Auditory Novelty Responses in Human Subjects.

In everyday life, predictable sensory stimuli are generally not ecologically informative. By contrast, novel or unexpected stimuli signal ecologically salient changes in the environment. This idea forms the basis of the predictive coding hypothesis: efficient sensory encoding minimizes neural activity associated with predictable backgrounds and emphasizes detection of changes in the environment. In real life, the brain must resolve multiple unexpected sensory events occurring over different time scales. The local/global deviant experimental paradigm examines auditory predictive coding over multiple time scales. For short-term novelty [hundreds of milliseconds; local deviance (LD)], sequences of identical sounds (/xxxxx/) are interspersed with sequences that contain deviants (/xxxxy/). Long-term novelty [several seconds; global deviance (GD)] is created using either (a) frequent /xxxxx/ and infrequent /xxxxy/ sequences, or (b) frequent /xxxxy/ and infrequent /xxxxx/ sequences. In scenario (a), there is both an LD and a GD effect (LDGD, “double surprise”). In (b), the global deviant is a local standard, i.e., sequence of identical sounds (LSGD). Cortical responses reflecting LD and GD originate in different brain areas, have a different time course, and are differentially sensitive to general anesthesia. Neural processes underlying LD and GD have been shown to interact, reflecting overlapping networks subserving the detection of novel auditory stimuli. This study examined these interactions using intracranial electroencephalography in neurosurgical patients. Subjects performed a GD target detection task before and during induction of anesthesia with propofol. Recordings were made from the auditory cortex, surrounding auditory-related and prefrontal cortex in awake, sedated, and unresponsive states. High gamma activity was used to measure the neural basis of local-by-global novelty interactions. Positive interaction was defined as a greater response to the double surprise LDGD condition compared to LSGD. Negative interaction was defined as a weaker response to LDGD. Positive interaction was more frequent than negative interaction and was primarily found in auditory cortex. Negative interaction typically occurred in prefrontal cortex and was more sensitive to general anesthesia. Temporo-parietal auditory-related areas exhibited both types of interaction. These interactions may have relevance in a clinical setting as biomarkers of conscious perception in the assessment of depth of anesthesia and disorders of consciousness.