In this report, we describe the case of a patient who has remained in a comatose state for more than one year after a traumatic and hypoxic brain injury. This state, which we refer to as long-lasting coma (LLC), may be a disorder of consciousness with significantly different features from those of conventional coma, the vegetative state, or brain death. On the basis of clinical, neurophysiological and neuroimaging data, we hypothesize that a multilevel involvement of the ascending reticular (...) activating system is required in LLC. This description may be useful for the identification of other patients suffering from this severe disorder of consciousness, which raises important ethical issues. (shrink)
Detecting conscious awareness in a patient emerging from a coma state is problematic, because our standard attributions of conscious awareness rely on interpreting bodily movement as intentional action. Where there is an absence of intentional bodily action, as in the vegetative state, can we reliably assume that there is an absence of conscious awareness? Recent neuroimaging work suggests that we can attribute conscious awareness to some patients in a vegetative state by interpreting their brain activity as intentional mental action. (...) I suggest that this change of focus, from the interpretation of motor behaviour as intentional bodily action to the interpretation of neural activity as intentional mental action, raises philosophical issues that affect the interpretation of the neuroimaging data. (shrink)
The essay examines Robin Cook’s Coma and Priscille Sibley’s The Promise of Stardust that dramatize the reified and disposable status of the brain-dead patients who are classified as nonpersons. The essay argues that the man-machine entanglement as depicted in the novels constructs a deterritorialized and entangled form of subjectivity that intervenes in the dominant biomedical understanding of personhood and agency that we notionally associate with a conscious mind. The essay concludes its arguments by discussing Alexander Beliaev’s Professor Dowell’s Head (...) which depicts human subjectivity as an essentially embodied and distributive phenomenon and interrogates the Cartesian mind body dualism embedded in the dominant biomedical narratives. (shrink)
Current research on the neural basis of consciousness is based mainly on neuroimaging, physiology and psychophysics. This target article reviews what is known about biochemical factors that may contribute to the development of consciousness, based on loss of consciousness (i.e., coma). There are two theories of the biochemical mode of action of general anaesthetics. One is that anaesthesia is a direct (i.e., not receptor-mediated) effect of the anaesthetic on cellular neurophysiological function; the other is that some alteration of receptor (...) function occurs. General anaesthetics are mainly GABA agonists but some (such as ketamine) are glutamate antagonists. They also affect other systems, particularly cholinergic ones. There are various comas of metabolic origin. For example, a combination of small doses of the iron chelators desferrioxamine and prochlorperazine induce a profound and long lasting coma in humans. The mechanisms that might mediate this include redox mechanisms at the glutamate synapse, post-synaptic endocytosis of dopamine and iron, and intracellular iron-dopamine complexes, which are powerful dismuters of the superoxide anion. New findings in cell biology relating to endocytosis and recycling of receptors are discussed in a wider context. These biochemical events may induce coma by two mechanisms: (i) Consciousness may depend on widespread cortical (or cortico-thalamic) activation. (ii) Whereas these biochemical changes are widespread, only the changes in a subset of consciousness' neurons may count. An experimental program to distinguish between these two alternatives is proposed. (shrink)
Following coma, some patients will recover wakefulness without signs of consciousness (only showing reflex movements, i.e., the vegetative state) or may show non-reflex movements but remain without functional communication (i.e., the minimally conscious state). Currently, there remains a high rate of misdiagnosis of the vegetative state (Schnakers et. al. BMC Neurol, 9:35, 8) and the clinical and electrophysiological markers of outcome from the vegetative and minimally conscious states remain unsatisfactory. This should incite clinicians to use multimodal assessment to detect (...) objective signs of consciousness and validate para-clinical prognostic markers in these challenging patients. This review will focus on advanced magnetic resonance imaging (MRI) techniques such as magnetic resonance spectroscopy, diffusion tensor imaging, and functional MRI (fMRI studies in both “activation” and “resting state” conditions) that were recently introduced in the assessment of patients with.. (shrink)
Jian Zhou,* Weiqiang Ju,* Xiaopeng Yuan, Xiaofeng Zhu, Dongping Wang, Xiaoshun HeOrgan Transplant Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China *These authors contributed equally to this work: Hyperosmolar nonketotic hyperglycemic coma is a serious, rare complication induced by methylprednisolone pulse therapy for acute rejection after orthotopic liver transplantation. Herein, we report an unusual case of a 58-year-old woman who experienced acute rejection at 30 months after OLT, only one case in which HNKHC resulted in (...) MP pulse therapy for acute rejection in all 913 recipients in our center. The general morbidity of HNKHC was 1.09‰ in this study. HNKHC is characterized by rapid onset, rapid progression, and a lack of specific clinical manifestations. High-dose MP management was a clear risk factor. The principle of treatment included rapid rehydration, low-dose insulin infusion, and correcting disorders of electrolytes and acidosis. In conclusion, clinicians considering MP pulse therapy after OLT should be alert to the occurrence of HNKHC. Keywords: liver transplantation, complications, hyperosmolar nonketotic hyperglycemic coma, methylprednisolone pulse therapy, principle of treatment. (shrink)
Herbert, Michael Clinicians are beginning to understand the varied outcomes following severe brain injury, one of which is post-coma unresponsiveness (PCU). However, much still needs to be done to fully comprehend this elusive state. Current clinical knowledge is outlined below.
McGovern, Kevin This article reviews three statements from the National Health and Medical Research Council on post-coma unresponsiveness (PCU). One of the functions of the NHMRC is to propose standards and guidelines for health care in Australia. The paper explores the causes and neuropathology of PCU, imaging and other tests and prognosis from unresponsiveness.
THE PRIMARY AIM OF THIS ESSAY is to advance discussion on how best to treat comatose patients. Its principal conclusion will be Some purportedly irreversibly comatose humans ought to be kept alive indefinitely. Of course, merely keeping such patients alive is not how best to treat them. How they are being treated while being kept alive is of paramount importance. Note that is compatible with the truth of All comatose humans ought to be kept alive indefinitely. I shall say nothing (...) more about. It will serve my present purpose if I can adequately defend, where "some" is to be understood in the usual manner, namely, as "at least one." The term "indefinitely," as one might surmise, is meant to convey some unspecified period of time. (shrink)
In 1968 the authors of the so-called Harvard Report, proposed the recognition of an irreversible coma as a new criterion for death. The proposal was accepted by the medical, legal, religious and political circles in spite of the lack of any explanation why the irreversible coma combined with the absence of brainstem reflexes, including the respiratory reflex might be equated to death. Such an explanation was formulated in the President’s Commission Report published in 1981. This document stated, that (...) the brain is the central integrator of the body, therefore the destruction of the brain results in the lack of that integration and the death of the organism. Therefore, according to that document, the so-called “brain dead” patients are really, biologically dead; strictly speaking they are not any more biological organisms but collections of organs and tissues. Their death was masked by the use of the medical equipment, but it was a real, biological death. Thus, the explanation given by the President’s Commission Report constituted a biological rationale for the new concept of death, known as “brain death.” However, after the long discussion, this rationale was refuted because of the evidence given by many medical authorities, that the bodies of the “brain dead” and “brainstem dead” patients are alive. In the context of the discussion about the neurological criteria for death, some authors follow the idea of Plato, that human being is the soul or mind, and the body does not belong to the human essence. Therefore, the loss of consciousness, which may be identified with the mind, constitutes the loss of personhood and may be interpreted as human death. The other group stresses the Aristotelian and Thomistic concept that the body belongs to the essence of every living creature, including human. Therefore, as long as the body is alive, the human being is alive and we cannot call the given patient dead even if he is deeply comatose. Moreover, in spite of the opinions dominating in the mass-media, these patients should be considered not only alive but also may be conscious to some degree and their state can be reversible. Their brains are lacking the electrical functions, but the neuronal tissue is alive and that state is reversible for at least first 48 hours since the onset of coma; this phenomenon is called “global ischemic penumbra” and is responsible for the regularly happening events interpreted as miracles, when some of the “brain dead” or “brainstem dead” patients turn to be alive and come back to normal life. Therefore, the neurological criteria of death are still lacking generally accepted scientific basis and should not be used in medicine and in the legal systems as a basis for diagnosing comatose/having no brainstem reflexes/apneic patients dead. (shrink)
: If we were asked to draw a graph to represent the distribution of consciousness in the world around us based on objective criteria, we would definitely be in trouble. The two objective parameters that have been traditionally considered as a guide – the complexity of behavior and brain size – lead to paradoxical conclusions and turn out to be unsatisfactory, to say the least. We need to find novel, reliable metrics. However, these can be identified, validated and calibrated only (...) if we first tackle seriously the problem of recognizing consciousness in our fellow humans, a task which is far from being obvious. Keywords: Consciousness; Animal; Brain; Behaviour; Coma La distribuzione della coscienza: un difficile diagramma cartesiano Riassunto: Se ci chiedessero di tracciare un grafico per rappresentare la distribuzione della coscienza nel mondo che ci circonda su una base oggettiva, ci troveremmo sicuramente in difficoltà. I due criteri oggettivi che sono stati tradizionalmente presi in considerazione come guida – la complessità del comportamento e la dimensione del cervello – conducono a conclusioni paradossali rivelandosi, come minimo, insoddisfacenti. È necessario individuare altre misure. Ma queste potranno essere individuate, validate e calibrate soltanto se prima affronteremo seriamente il problema di riconoscere la coscienza nell’uomo, un compito tutt’altro che scontato. Parole chiave: Coscienza; Animale; Cervello; Comportamento; Coma. (shrink)
In the care of patients with disorders of consciousness (DOC), some ethical difficulties stem from the challenges of accurate diagnosis and the uncertainty of prognosis. Current neuroimaging research on these disorders could eventually improve the accuracy of diagnoses and prognoses and therefore change the context of end-of-life decision making. However, the perspective of healthcare professionals on these disorders remains poorly understood and may constitute an obstacle to the integration of research. We conducted a qualitative study involving healthcare professionals from an (...) acute care university medical center. A short questionnaire captured demographic data as well as the experience of participants with DOC patients. A semi-structured interview was used to explore attitudes toward ethical issues identified in a previous literature review. Qualitative content analysis of interviews was conducted with the NVivo software. Accurate diagnosis among DOC is often regarded as a challenge, but this was generally not the case for our participants because most reported high confidence in DOC diagnoses. However, participants reported struggling with prognosis, especially because of its essential role for end-of-life decision making and communication with families. Variability of opinion between healthcare professionals was reported and identified by some as a minor issue while others stressed how families struggle with different medical opinions. End-of-life decision making encompassed a large proportion of ethical challenges in these patients, and the removal of artificial nutrition and hydration created significant discomfort in a minority of participants. The concept of futility was subject to wide-ranging understandings with both favorable and unfavorable opinions. Our data suggest that to ensure the incorporation of new evidence-based advances, attention should be directed to the real-world practices and challenges of accurate diagnosis and prognosis. Given pervasive challenges in end-of-life care, we recommend improved training of healthcare professionals in the care of patients with DOC, particularly in end-of life care, understanding the context of decision making, and determining how to optimally integrate new neuroscience research on the care of patients with DOC. (shrink)
After severe brain injury, one of the key challenges for medical doctors is to determine the patient’s prognosis. Who will do well? Who will not do well? Physicians need to know this, and families need to do this too, to address choices regarding the continuation of life supporting therapies. However, current prognostication methods are insufficient to provide a reliable prognosis. -/- Functional Magnetic Resonance Imaging (MRI) holds considerable promise for improving the accuracy of prognosis in acute brain injury patients. Nonetheless, (...) research on functional MRI in the intensive care unit context is ethically challenging. These studies raise several ethical issues that have not been addressed so far. In this article, Prof. Charles Weijer and his co-workers provide a framework for researchers and ethics committees to design and review these studies in an ethically sound way. (shrink)
Zum Hirntod werden zwei Fragen erneut kontrovers diskutiert: erstens, ob der Hirntod mit dem Tod gleichzusetzen ist, zweitens, wie man den Hirntod sicher diagnostiziert. Neue empirische Erkenntnisse erfordern eine neue Auseinandersetzung mit diesen Fragen: Erstens haben zahlreiche Studien ein längeres Überleben und die Integration von Körperfunktionen von hirntoten Patienten nachgewiesen. Der President's Council on Bioethics hat im Dezember 2008 eingestanden, dass die bisher vertretene Begründung für das Hirntodkriterium, nämlich die Annahme des engen zeitlichen und kausalen Zusammenhangs des Hirntodes und der (...) Desintegration der körperlichen Funktionen, empirisch widerlegt sei. Trotzdem hält der Council am Hirntodkriterium fest, stützt es aber nun auf eine neue naturphilosophische statt empirische Begründung, die den lebenden Organismus über die aktive Auseinandersetzung mit der Welt als notwendiges Kriterium für Leben bestimmt. Diese naturphilosophische Begründung ist nicht falsifizierbar und scheint den Interessen der Transplantationsmedizin geschuldet. Zweitens geben Studien mit fMRT und PET an hirntoten Patienten Anlass, an der Reliabilität der üblichen Hirntoddiagnostik zu zweifeln. Aus ethischen Gründen sollte eine Hirntoddiagnostik auf dem Stand der besten verfügbaren Technologie gesetzlich vorgeschrieben werden, also zumindest die Angiographie, in Zweifelsfällen auch fMRT oder PET. (shrink)
The prospect, in terms of subjective expectations, of immortality under the no-collapse interpretation of quantum mechanics is certain, as pointed out by several authors, both physicists and, more recently, philosophers. The argument, known as quantum suicide, or quantum immortality, has received some critical discussion, but there hasn't been any questioning of David Lewis's point that there is a terrifying corollary to the argument, namely, that we should expect to live forever in a crippled, more and more damaged state, that barely (...) sustains life. This is the prospect of eternal quantum torment. Based on some empirical facts, I argue for a conclusion that is much more reassuring than Lewis's terrible scenario.1. (shrink)
When an individual is comatose while parts of her brain remain functional, the question arises as to whether any mental characteristics are still associated with this brain, that is, whether the person still exists. Settling this uncertainty requires that one becomes clear about two issues: the type of functional loss that is associated with the respective profile of brain damage and the persistence conditions of persons. Medical case studies can answer the former question, but they are not concerned with the (...) latter. Conversely, in the philosophical literature, various accounts of personal identity are discussed, but usually detached from any empirical basis. Only uniting the two debates and interpreting the real-life configurations of brain damage through the lens of the philosophical concepts enables one to make an informed judgment regarding the persistence of comatose persons. Especially challenging are cases in which three mental characteristics that normally occur together—wakefulness, awareness and memory storage—come apart. These shall be the focus of this paper. (shrink)