Confirmatory tests in the diagnosis of brain death: The role of the radioisotope brain scan

In recent years physicians have used a variety of laboratory studies as confirmatory tests in the diagnosis of brain death. The most widely used test has been the EEG. However, with the development of newer technologies capable of measuring other parameters of brain functions, other laboratory studies are playing an increasingly important role in confirming brain death. In this article, we discuss the role of one of these newer tests, the radioactive brain scan, and compare its advantages and limitations with the EEG.     

Carson Strong's “positive killing and the irreversibly unconscious patient”: A commentary

There is general agreement that death of the entire brain results in death of the person, and that such a condition can exist in a body which is still technically “alive.”1,2 Dr. Strong additionally contends that in cases of irreversible coma, since cognitive abilities characteristic of the person are no longer manifest and cannot be expected to reappear, such an individual no longer has the “right to life” and somatic death can be initiated by “positive killing.” This, the author claims, can be considered a logical and morally acceptable extension of the conceptual framework now in force for dealing with cases of isolated brain death.     

诊断脑死亡的伦理思考

随着医学的进步和社会的发展,死亡的定义、诊断标准和医生道德责任有了新的内容,脑死亡就是生命终结已为医学界普遍接受.诊断脑死亡是非常专业的技术性工作,有权进行脑死亡诊断的医疗单位和医生必须达到相应的资质要求.确诊和宣布脑死亡应遵循的伦理准则包含多方面的内容,如家属应有死亡标准选择权、脑死亡的诊断程序、脑死亡诊断结果的宣布和生效等方面的问题.     

脑死亡立法的艰难与中国传统文化

因中国传统伦理文化对人们意识观念的深刻影响导致中国脑死亡立法步履艰难。从中国传统文化视角分析中国的脑死亡及相关伦理问题,提出中国脑死亡诊断标准的制定必须充分考虑民族心理感受,要立足于民族文化理性地探索“中国脑死亡”。     

Epistemology of brain death determination

This article assesses what standards of safety and certainty of diagnosis need to be met in the determination of brain death. Recent medical, legal, and philosophical developments on brain death are summarized. It is argued that epistemologically adequate standards require the finding of whole-brain death rather than destruction of the cortex. Because of the possibility of positive error in misdiagnosing death, a tutioristic approach of ‘being on the safe side’ is advocated. Given uncertainties in diagnosis of so-called vegetative states like the apallic syndrome, anything less than whole-brain death, especially given the present state of diagnostic capability, should not qualify as an argument for removing therapy specifically on grounds that the patient is dead.     

Reduced electroencephalographic coherence asymmetry in the Chernobyl accident survivors

An electroencephalograph (EEG) study was carried out from 1990 to 2006, using power spectra, averaged coherence, and integral EEG coherence asymmetry coefficients to compare 189 clean-up workers of the Chernobyl accident with 63 age-matched healthy controls. Most of the Chernobyl workers showed three abnormal EEG patterns, as indicated by EEG power mapping. The higher power, most prominent in slow alpha and theta bands, or in fast alpha frequencies, were observed in persons 3-5 years after the clean-up works (the early stage). The lower EEG power in alpha band was found in Chernobyl workers 10 or more years after the accident (the late stage). EEG coherence analysis revealed the existence of two stages in EEG alterations following the Chernobyl clean-up. In the early stage, an increase of EEG coherence in the central brain areas was observed, whereas at the later stage, a decrease of EEG coherence, most prominent in the frontal brain areas, and reduced brain asymmetry prevailed. These results allow us to propose that the described EEG signs may be a reflection of radiation-induced brain dysfunction at the late period after the Chernobyl clean-up and were similar to the EEG markers of brain ageing. The results, in comparison to data of the literature, provide additional support to the premature brain ageing hypothesis in Chernobyl survivors as a result of the radiation brain damage after-effect.     

Brain tumor detection using fusion of hand crafted and deep learning features

The perilous disease in the worldwide now a days is brain tumor. Tumor affects the brain by damaging healthy tissues or intensifying intra cranial pressure. Hence, rapid growth in tumor cells may lead to death. Therefore, early brain tumor diagnosis is a more momentous task that can save patient from adverse effects. In the proposed work, the Grab cut method is applied for accurate segmentation of actual lesion symptoms while Transfer learning model visual geometry group (VGG-19) is fine-tuned to acquire the features which are then concatenated with hand crafted (shape and texture) features through serial based method. These features are optimized through entropy for accurate and fast classification and fused vector is supplied to classifiers. The presented model is tested on top medical image computing and computer-assisted intervention (MICCAI) challenge databases including multimodal brain tumor segmentation (BRATS) 2015, 2016, and 2017 respectively. The testing results with dice similarity coefficient (DSC) achieve 0.99 on BRATS 2015, 1.00 on BRATS 2015 and 0.99 on BRATS 2017 respectively.     

The degree of certainty in brain death: probability in clinical and Islamic legal discourse

The University of Michigan conference “Where Religion, Policy, and Bioethics Meet: An Interdisciplinary Conference on Islamic Bioethics and End-of-Life Care” in April 2011 addressed the issue of brain death as the prototype for a discourse that would reflect the emergence of Islamic bioethics as a formal field of study. In considering the issue of brain death, various Muslim legal experts have raised concerns over the lack of certainty in the scientific criteria as applied to the definition and diagnosis of brain death by the medical community. In contrast, the medical community at large has not required absolute certainty in its process, but has sought to eliminate doubt through cumulative diagnostic modalities and supportive scientific evidence. This has recently become a principal model, with increased interest in data analysis and evidence-based medicine with the intent to analyze and ultimately improve outcomes. Islamic law has also long employed a systematic methodology with the goal of eliminating doubt from rulings regarding the question of certainty. While ample criticism of the scientific criteria of brain death (Harvard criteria) by traditional legal sources now exists, an analysis of the legal process in assessing brain death, geared toward informing the clinician’s perspective on the issue, is lacking. In this article, we explore the role of certainty in the diagnostic modalities used to establish diagnoses of brain death in current medical practice. We further examine the Islamic jurisprudential approach vis-à-vis the concept of certainty (yaqīn). Finally, we contrast the two at times divergent philosophies and consider what each perspective may contribute to the global discourse on brain death, understanding that the interdependence that exists between the theological, juridical, ethical, and medical/scientific fields necessitates an open discussion and active collaboration between all parties. We hope that this article serves to continue the discourse that was successfully begun by this initial interdisciplinary endeavor at the University of Michigan.     

Informed consent for the diagnosis of brain death: a conceptual argument

Background

This essay provides an ethical and conceptual argument for the use of informed consent prior to the diagnosis of brain death. It is meant to enable the family to make critical end-of-life decisions, particularly withdrawal of life support system and organ donation, before brain death is diagnosed, as opposed to the current practice of making such decisions after the diagnosis of death. The recent tragic case of a 13-year-old brain-dead patient in California who was maintained on a ventilator for over 2 years illustrates how such a consent would have made a crucial difference.

Methods

Conceptual, philosophical, and ethical analysis.

Results

I first consider a conceptual justification for the use of consent for certain non-beneficial and unwanted medical diagnoses. I suggest that the diagnosis of brain death falls into this category for some patients. Because the diagnostic process of brain death lacks the transparency of traditional death determination, has a unique epistemic structure and a complex risk-benefit profile which differs markedly from case to case, and presents conflicts of interest for physicians and society, I argue that pre-diagnostic counseling and informed consent should be part of the diagnostic process. This approach can be termed as “allow cardiac death”, whose parallel logic with “allow natural death” is discussed. I also discuss potential negative impacts on organ donation and health care cost from this proposal and offer possible mitigation. I show that the pre-diagnostic counseling can improve the possibility for well-thought-out decisions regarding organ donation and terminating life-support system in cases of hopeless prognosis. This approach differs conceptually from the pluralism of the definition of death, such as those in New Jersey and Japan, and it upholds the Uniform Determination of Death Act.

Conclusions

My intention is not to provide an instant panacea for the ongoing impasse of the brain death debate, but to point to a novel conceptual ground for a more pragmatic, and more patient- and family-centered approach. By enabling the family to consent to or decline the diagnostic process of brain death, but not to choose the definition of death, it upholds the current legal definition of death.

     

Possibilities and limits of the diagnosis of specific learning disorders with neurophysiologic methods of study

EEG correlation analyses were conducted with children with and without specific learning weaknesses. Reduced left parietal correlation was found in children with dyslectic problems, and in children with adjustment and concentration problems, reduced bioelectric correlation. The frequent evidence of brain injury criteria suggests a link with general affectations of correlation but not specifically with cerebral correlation affections. It would appear to be appropriate to employ computer-assisted EEG correlation analysis, together with frequency analysis and the examination of evoked potentials in objective neurometric diagnosis where children with learning weaknesses are involved.     

Changes of chaoticness in spontaneous EEG/MEG

Depending on the task being investigated in EEG/MEG experiments, the corresponding signal is more or less ordered. The question still open is how can one detect the changes of this order while the tasks performed by the brain vary continuously. By applying a static measurement of the fractal dimension or Lyapunov exponent, different brain states could be characterized. However, transitions between different states may not be detected, especially if the moments of transitions are not strictly defined. Here we show how the dynamical measure based on the largest local Lyapunov exponent can be applied for the detection of the changes of the chaoticity of the brain processes measured in EEG and MEG experiments. In this article, we demonstrate an algorithm for computation of chaoticity that is especially useful for nonstationary signals. Moreover, we introduce the idea that chaoticity is able to detect, locally in time, critical jumps (phase-transition-like phenomena) in the human brain, as well as the information flow through the cortex.     

多人交互同步记录技术在大脑神经活动测量中的应用*

多人交互同步记录是一种新技术,可以实现同时对多人的脑活动进行测量,现已被越来越多地应用到社会交互的研究中。本文从不同技术角度出发,回顾已经发表的有关多人交互同步记录的研究,从中可以了解不同的脑活动记录技术是如何被应用到各种实验范式中,以及人脑间是如何动态交互的。同时本文也对不同的多人交互同步记录技术的优缺点进行了比较。鉴于该方法的优势,其在未来的社会交互研究中具有广泛的应用前景。     

The relationship between psychological test results and EEG patterns in healthy children

222 children (112 girls and 110 boys) aged 5–16 years with different types of EEG pattern, selected according to well defined normal criteria in order to exclude cerebral lesion elements, were investigated by current child-psychiatric diagnostic methods, including the Wechsler Intelligence Scale for children (WISC), which gave a mean IQ of 116.5. With two so-called tests of organicity (Bender Gestalt Test and Benton's Revised Visual Retention Test) poor performances indicating brain damage were shown in 22% and 24% of the children respectively. Various EEG patterns showed few significant correlations with the test variables. According to clinical judgement "slight symptoms of cerebral dysfunction" was found in some children, but no correlation appeared between such symptoms and poor performance in the psychological tests. The high frequency of defective scores in the Bender and Benton tests in this selected material of healthy children means that these tests cannot be used in clinical work for diagnosing brain injury in individual children. Nor can they be used to throw light on the clinical significance of the different EEG variables studied.     

Different Brain Wave Patterns and Cortical Control Abilities in Relation to Different Creative Potentials

Contemporary understanding of brain functions provides a way to probe into the mystery of creativity. However, the prior evidence regarding the relationship between creativity and brain wave patterns reveals inconsistent conclusions. One possible reason might be that the means of selecting creative individuals in the past has varied in each study. By distinguishing creative potential as open-ended versus closed-ended based on theoretical views, this study examined different brain wave patterns and cortical control abilities in relation to different creative potentials by using electroencephalogram (EEG) biofeedback equipment. The results demonstrated that participants’ performance on the open-ended creative problem was positively related to EEG alpha frequencies, whereas performance on the closed-ended creative problem was related to larger variability in EEG dynamics between alpha and beta waves when performing either open-ended or closed-ended creativity tasks. Further, better control in changing states of brain wave activities according to the EEG biofeedback signals could predict closed-ended creativity performance. Open-ended creativity was related only to the enhancement of alpha signals. These results help clarify previous inconsistent findings, reveal different natures of distinct creativities, and further suggest ways to improve different aspects of creativity with modified biofeedback procedures.     

Reconsidering the dead donor rule: is it important that organ donors be dead?

The "dead donor rule" is increasingly under attack for several reasons. First, there has long been disagreement about whether there is a correct or coherent definition of "death." Second, it has long been clear that the concept and ascertainment of "brain death" is medically flawed. Third, the requirement stands in the way of improving organ supply by prohibiting organ removal from patients who have little to lose--e.g., infants with anencephaly--and from patients who ardently want to donate while still alive--e.g., patients in a permanent vegetative state. One argument against abandoning the dead donor rule has been that the rule is important to the general public. There is now data suggesting that this assumption also may be flawed. These findings add additional weight to proposals to abandon the dead donor rule so that organ supply can be expanded in a way that is consistent with traditional notions of ethics, law, public policy, and public opinion.     

EEG相干分析在语言理解研究中的应用

EEG相干反映了EEG信号在各个脑区之间的信息传递,可以揭示各种认知加工过程中不同功能网络的协同工作方式。首先介绍了这一方法的基本原理,然后从词语和句子两个水平上阐述了EEG相干分析在语言理解研究中的应用。在词语水平上涉及一般认知加工过程、语法加工和语义加工三个方面;在句子水平上,从句子的语义整合角度进行了介绍。最后指出了这一方法的优缺点,并对今后的研究方向进行了展望     

Interpretation of paroxysmal slow activity--"subcortical signs"--in the electroencephalography of adults

Slow paroxysmal EEG activity, also referred to as "subcortical signs", offers an indication of impaired subcortico-cortical functional interaction that may be set off as a result of intracranial processes of a wide range of localisation. For this reason, the occurrence of this EEG pattern should not be taken to indicate a primary localisation in the range of the medical subcortical structures, nor does its absence imply any improbability of extensive lesions in the region. Taking into consideration the form and frequency of the waves during paroxysms and their local distribution, even this aspecific pattern yields more information for the clinical diagnosis. In particular, generalised paroxysms from monomorphic delta waves are usually associated with an existing primary or secondary brain illness, and would suggest the need for further diagnostic clarification. In interpreting the slow-wave groups restricted to the temporal regions, frequently counted among the "subcortical signs", the wave frequency and the patient's age must be taken into account. In the second half of life they frequently occur unaccompanied by any pathological process.     

Resting frontal brain asymmetry predicts affective responses to films

This article assessed whether resting electroencephalographic (EEG) asymmetry in anterior regions of the brain can predict affective responses to emotion elicitors. Baseline EEG was recorded from 32 female adults, after which Ss viewed film clips preselected to elicit positive or negative affect. Resting alpha power asymmetry in the frontal region significantly predicted self-reported global negative affect in response to clips and predicted the difference between global positive and negative affect. Analyses of discrete emotions revealed a strong relation between frontal asymmetry and fear responses to films. Effects were independent of Ss mood ratings at the time at which baseline EEG was measured. Resting anterior asymmetry may be a state-independent index of the individual's predisposition to respond affectively.     

Clarifying the paradigm for the ethics of donation and transplantation: Was 'dead' really so clear before organ donation?

Recent commentaries by Verheijde et al, Evans and Potts suggesting that donation after cardiac death practices routinely violate the dead donor rule are based on flawed presumptions. Cell biology, cardiopulmonary resuscitation, critical care life support technologies, donation and transplantation continue to inform concepts of life and death. The impact of oxygen deprivation to cells, organs and the brain is discussed in relation to death as a biological transition. In the face of advancing organ support and replacement technologies, the reversibility of cardiac arrest is now purely related to the context in which it occurs, in association to the availability and application of support systems to maintain oxygenated circulation. The 'complete and irreversible' lexicon commonly used in death discussions and legal statutes are ambiguous, indefinable and should be replaced by accurate terms. Criticism of controlled DCD on the basis of violating the dead donor rule, where autoresuscitation has not been described beyond 2 minutes, in which life support is withdrawn and CPR is not provided, is not valid. However, any post mortem intervention that re-establishes brain blood flow should be prohibited. In comparison to traditional practice, organ donation has forced the clarification of the diagnostic criteria for death and improved the rigour of the determinations.     

Electroencephalographic intercentral interaction as a reflection of normal and pathological human brain activity

The authors summarized EEG findings and defined the nature of the intercentral EEG relationships in different functional states in healthy subjects and patients with organic cerebral pathology, based on a coherence analysis. Similar EEG characteristics in healthy individuals were identified: an anterior-posterior gradient of average coherence levels, the type of cortical-subcortical relationships in anterior cerebral structures. Right- and left-handed individuals showed frequent and regional differences in EEG coherence, which mainly reflected specificity of intracortical relationships. Development and regression of pathology in right-and left-handed individuals with organic brain lesions were thought to be caused by these differences. Lesions of regulatory structures (diencephalic, brain stem and limbic structures) provoked a more diffused kind of changes of intercentral relationships, in contrast to cortical pathology. These changes tended to reciprocate. The dynamic nature of intercentral relationships and their interhemispheric differences was revealed when changing functional states of the brain (increase and decrease of functional level) in healthy individuals and patients with organic cerebral pathology in the process of conscious and psychic activity restoration. Changing activity predominance of certain regulatory structures was considered one of the most important factors determining the dynamic nature of EEG coherence.