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HOLDING: Tube feeding may be withheld or withdrawn from a person in a persistent semi-conscious state even though her living will did not explicitly decline tube feeding, and there is no clear and convincing evidence of her intention to decline tube feeding.
Comatose, vegetative, minimally conscious or locked-in patients represent a problem in terms of diagnosis, prognosis, treatment and everyday management at the intensive care unit. The evaluation of possible cognitive functions in these patients is difficult because voluntary movements may be very small, inconsistent and easily exhausted. Functional neuroimaging cannot replace the clinical assessment of patients with altered states of consciousness. Nevertheless, it can describe objectively how deviant from normal the cerebral activity is and its regional distribution at rest and under various conditions of stimulation. The quantification of brain activity differentiates patients who sometimes only differ by a brief and incomplete blink of an eye. In the present paper, we will first try to define consciousness as it can be assessed at the patient's bedside. We then review the major clinical entities of altered states of consciousness encountered in the intensive care unit. Finally, we discuss the functional neuroanatomy of these conditions as assessed by positron emission tomography (PET) scanning.
A cytopathic 'stealth' virus was cultured from the cerebrospinal fluid of a patient with a bipolar psychotic disorder who developed a severe encephalopathy leading to a vegetative state. DNA sequencing of a polymerase chain reaction-amplified product from infected cultures has identified the virus as an African green monkey simian cytomegalovirus (SCMV)-related stealth virus. The virus is similar to the SCMV-related stealth virus isolated from a patient with chronic fatigue syndrome. The findings support the concepts that stealth viruses can account for a spectrum of dysfunctional brain diseases and that some of these viruses may have arisen from live polio viral vaccines.
A young woman was rendered tetraplegic and anarthric as a result of a traumatic brain injury in 1993. Two years later, she was considered to be in a minimally conscious state and became the subject of legal debate in the UK with regard to withdrawal of artificial feeding and hydration. Before injury, she made a verbal advanced directive that she would not wish to continue living if ever becoming severely disabled. Neuropsychological assessment found statistically significant evidence for sentience and expression of a wish to live and the application to Court was withdrawn. Further meaningful recovery occurred between 7-10 years after injury. She now lives in the community with 24 hour care. She speaks, initiates conversation and actions, expresses clear and consistent preferences and has a spontaneous sense of humour. She uses an electric wheelchair, eats solid food and drinks through a straw. Her mood is variable and sometimes low. This case demonstrates the need for careful consideration of advanced directives and for specialist neuropsychological assessment in people with severe cognitive and communication difficulties. It supports the view that routine assessment and follow-up of people thought to be in minimally conscious states is important. In addition, it shows that recovery with reduction in disability and significant implications for quality of life can continue for at least 10 years after extremely severe traumatic brain injury.
We review cerebral processing of auditory and noxious stimuli in minimally conscious state (MCS) and vegetative state (VS) patients. In contrast with limited brain activation found in VS patients, MCS patients show activation similar to controls in response to auditory, emotional and noxious stimuli. Despite an apparent clinical similarity between MCS and VS patients, functional imaging data show striking differences in cortical segregation and integration between these two conditions. However, in the absence of a generally accepted neural correlate of consciousness as measured by functional neuroimaging, clinical assessment remains the gold standard for the evaluation and management of severely brain damaged patients.
We review the nosological criteria and functional neuroanatomical basis for brain death, coma, vegetative state, minimally conscious state, and the locked-in state. Functional neuroimaging is providing new insights into cerebral activity in patients with severe brain damage. Measurements of cerebral metabolism and brain activations in response to sensory stimuli with PET, fMRI, and electrophysiological methods can provide information on the presence, degree, and location of any residual brain function. However, use of these techniques in people with severe brain damage is methodologically complex and needs careful quantitative analysis and interpretation. In addition, ethical frameworks to guide research in these patients must be further developed. At present, clinical examinations identify nosological distinctions needed for accurate diagnosis and prognosis. Neuroimaging techniques remain important tools for clinical research that will extend our understanding of the underlying mechanisms of these disorders.
Physicians may employ the concept of medical futility to justify a decision not to pursue certain treatments that may be requested or demanded by patients or surrogates. Medical futility means that the proposed therapy should not be performed because available data show that it will not improve the patient's medical condition. Medical futility remains ethically controversial for several reasons. Some physicians summarily claim a treatment is futile without knowing the relevant outcome data. There is no unanimity regarding the statistical threshold for a treatment to be considered futile. There is often serious disagreement between physicians and families regarding the benefits to the patient of continued treatment. Medical futility has been conceptualized as a power struggle for decisional authority between physicians and patients/surrogates. Medical futility disputes are best avoided by strategies that optimize communication between physicians and surrogates; encourage physicians to provide families with accurate, current, and frequent prognostic estimates; assure that physicians address the emotional needs of the family and try to understand the problem from the family's perspective; and facilitate excellent palliative care through the course of the illness. Critical care physicians should support the drafting of state laws embracing futility considerations and should assist hospital policymakers in drafting hospital futility policies that both provide a fair process to settle disputes and embrace an ethic of care.
OBJECTIVE: To discover if the neuropathology differs in head-injured patients who were in a vegetative state (VS) or were severely disabled at time of death. METHODS: Review of 35 VS cases and 30 severely disabled cases treated in this institute in the acute stage, surviving at least a month; all brains were fixed for 3 weeks before full neuropathologic examination. RESULTS: The severely disabled cases were older, had a higher incidence of skull fracture and of evacuated intracranial hematoma, and they had more cortical contusions. Diffuse axonal injury (DAI) was less common in the severely disabled cases, particularly its most severe grade. Structural damage in the thalamus was much less common in severely disabled cases. Half of the severely disabled patients had neither grade 2 or 3 DAI nor thalamic damage and 10 of these 15 cases did not have ischemic brain damage either. These combinations did not occur in a single VS case. However, some severely disabled cases had similar lesions to VS cases, and this included some patients who were in a minimally conscious state as well as some who were out of bed and mobile. CONCLUSIONS: Half the severely disabled cases had only focal brain damage, a feature not found in any VS cases. In the severely disabled patients with lesions similar to those of VS cases it is likely that a greater quantitative amount of damage occurred in the VS cases.
This case report describes a patient in vegetative state after severe traumatic brain injury (TBI) with hypothalamic damage and clinical manifestations of autonomic dysfunction. He also presented late onset paroxysmal hypothermia associated with mild bradycardia and hypotension. Hypothermia due to traumatic lesions of the hypothalamus is an uncommon clinical problem and few cases have been reported; no cases could be found in the literature which evidenced periodic hypothermia associated with clinical features of autonomic dysfunction after TBI. In the article, the main causes and the primary pathophysiology of hypothermia after TBI are discussed. The manifestations in this patient have been interpreted as possible consequences of autonomic dysfunction and considered atypical and rare clinical expression of acute post-traumatic hypothalamic instability.
A systematic neuropsychological assessment technique is described for use with severely physically disabled people who may be severely brain-damaged, in an incomplete locked-in state or potentially in vegetative state. The technique allows opinions regarding cognitive state to be statistically based. In the case described, the weight of expert opinion had been that involuntary feeding by gastrostomy tube should be terminated because the patient was functioning at a level little beyond the vegetative state, her quality of life was poor and she was unable to form a view about her present or future circumstances. An assessment approach is described which uses binomial statistics and allows for some variability in responding. Methods of minimizing sources of extraneous bias are also discussed. By use of this technique it was demonstrated that the patient was sentient though impaired, and that her own wish at the time of the assessment was to continue living. It is recommended that neuropsycholgical assessment of this kind should take place in all cases in which withdrawal of treatment is being considered and cognitive ability is not certain.
Epidemiological studies made within the western countries indicate an incidence of 200-300 traumatic head injuries per 100 000 residents each year. Severe head injuries account for 5-25% of all head injuries; 10-14% of all severe head-injured patients develop into a vegetative state, in which a sleep-wake rhythm is apparent, but however in which there is no evidence of awakeness or reactivity to the environment. The most commonly used labels, in the German and international literature, for these patients are 'vegetative state', 'apallic syndrome' and 'coma vigile'. This clinical characterization is not sufficient. It is necessary to employ additional criteria to distinguish subsets of vegetative patients e.g. computerized tomography, magnetic resonance imaging, single photon emission tomography, electroencephalography, brainstem reflexes, evoked potentials, assessment scales, age, premorbid brain disorders. Diagnostic and prognostic parameters must form the basis for various decisions relating to patients' care and intervention.
An important question for physicians in the aftermath of the Terri Schiavo case is whether the effort of elected officials to intervene was a one-time anomaly or signals a future trend of elected officials being involved in cases where patients are in a vegetative or long-term comatose state. To try to answer this question, we used results from 12 national opinion surveys conducted in March and April 2005, when the Schiavo case was being debated. A review of these survey results showed that efforts by elected politicians to intervene in the Schiavo case were opposed by the majority of Americans. However, the public was more divided on the question of whether Schiavo's feeding tube should be removed. Opposition to removing Schiavo's feeding tube was associated with opposition to abortion. The results suggest that issues involved in cases like Schiavo's are not likely to disappear from the political agenda.
BACKGROUND: The early post-traumatic vegetative state (VS) is compatible with recovery. Various clinical and laboratory tests have failed to predict recovery so we assessed the value of cerebral magnetic-resonance imaging (MRI) in prediction of recovery. METHODS: 80 adult patients in post-traumatic VS had cerebral MRI between 6 weeks and 8 weeks after injury. MRIs were reviewed by three neuroradiologists for the number, sizes, and location of brain lesions. Three neurologists assessed the patients at the time of MRI and at 2 months, 3 months, 6 months, 9 months, and 12 months after injury using the Glasgow Outcome Scale. FINDINGS: At 12 months, 38 patients had recovered while 42 patients remained in the VS. The demographic characteristics and causes and severity of injury were similar in patients in persistent VS (PVS) and those who recovered (NPVS). An average of 6.1 different brain areas were injured in patients in PVS compared with 4.6 areas in patients who had NPVS. Patients in PVS revealed a significantly higher frequency of corpus callosum, corona radiata, and dorsolateral brainstem injuries than did patients who recovered. Logistic regression analysis showed that corpus callosum and dorsolateral brainstem injuries were predictive of non-recovery. The adjusted odds ratios for non-recovery of patients with a corpus callosum lesion and dorsolateral brainstem injury were 213.8 (95% CI 14.2-3213.3), and 6.9 (11-42.9), respectively. In contrast, clinical characteristics, such as initial score on the Glasgow Coma Scale, age, and pupillary abnormalities failed to predict recovery. INTERPRETATION: Cerebral MRI findings in the subacute stage after head injury can predict the outcome of the post-traumatic VS. Corpus callosum and dorsolateral brainstem lesions are highly significant in predicting non-recovery.
Three-modality evoked potentials (TMEPs) have been used for several years in association with the EEG as a diagnostic and prognostic tool in acute anoxic or traumatic coma. Cognitive EPs have been recently introduced. EEG and cognitive EPs provide functional assessment of the cerebral cortex. TMEP parameters can be described by two indices: the index of global cortical function (IGCF) and the index of brainstem conduction (IBSC). Although it remains a unique tool for epilepsy assessment, the value of EEG is largely limited by its high sensitivity to the electrical environmental noise, its dependence on sedative drugs, and its inability to test the brainstem. Major TMEP alterations (absence of cortical activities more than 24 hours after the onset of post-anoxic coma, major pontine involvement in head trauma) are associated in all cases with an ominous prognosis (death or vegetative state). However, even if mild TMEP changes are associated with a good prognosis in 65% (post-anoxic coma) to 90% (head trauma) of cases, some patients never recover despite exogenous TMEPs that are only mildly altered in the acute stage. Thus, cognitive EPs can usefully complement exogenous EPs as a prognostic tool in coma. Indeed, even if the absence of cognitive EPs in comatose patients does not have any prognostic value, their presence implies a very high (more than 90%) probability of consciousness recovery. The major technical challenge for the future will be the development of reliable tools for continuous EEG and TMEP monitoring.
Medicine's diagnostic and therapeutic capacities raise increasingly complex ethical and legal issues for consideration. This is particularly so when the patient is in a permanent vegetative state. This article reviews the current legal position in the case of adults in permanent vegetative state (pVS), with particular attention to the devices used by courts in reaching decisions about whether or not to prolong assisted nutrition and hydration. The article further considers the impact of the Human Rights Act 1998, and argues that the current legal position is significantly, if not determinatively, based on clinical judgement, even where there is some doubt about whether or not the cases actually meet the terms of the Royal College of Physicians (RCP) diagnostic guidelines. In addition, the article asks whether or not the devices used by courts to permit withdrawing assisted nutrition and hydration from patients in pVS could be categorised as assisted death, and notes the (arguable) weakness of these devices as a basis for derogation from the sanctity of life principle.
Event-related potentials (ERPs) can provide valuable information about cognitive capabilities in severely brain-damaged patients. This study examined 120 patients with severe brain damage using event related potentials ERPs (N 400) to gain information about their remaining semantic processing capabilities and to contribute to differential diagnosis. Patients were classified into three diagnostic groups: patients in vegetative state (VS), patients in near vegetative state (NEVS) and patients not in vegetative state (NOVS). N400 ERPs were analyzed on an individual basis. All three groups could be differentiated by N400. While VS-patients as a group were least likely to show N400, some VS-patients (approx. 12%) showed clear semantic N400 potentials as an indication of semantic processing capabilities. Patients in NEVS showed significantly more intact semantic capabilities (76.74%) than the VS-group despite little clinical differences between the two groups. Thus, ERPs provide valuable information about patients with brain injury whose clinical conditions often do not allow a true assessment of their cognitive capabilities. Given these findings, we would espouse that both ethical and legal debate should take into account results of ERP studies of such patients.
The past decade has provided a wealth of data for theorists of visual awareness. Two empirical approaches, both seeking to dissociate conscious from unconscious neural processes, have been particularly fruitful. The first has focused on the neural correlates of changes in experience occurring in the absence of change in external stimuli, for example during binocular rivalry; the second has investigated the neural correlates of unconscious processes such as blindsight. Several of the theories based on these data propose that visual consciousness arises from interactions between thalamo-cortical modules whose independent operation is unconscious; popular candidate 'modules' include visual regions in the 'ventral' visual pathway and parieto-frontal regions associated with action planning. These theories can be tested against recent findings from patients in the vegetative state, a state of 'wakefulness without awareness', which can follow major insults to the brain. The findings indicate that stimulus-evoked cortical activity occurs in the vegetative state, but tends to be limited in extent, is often restricted to primary sensory areas, and is poorly integrated with activity elsewhere in the cerebrum. The theories of visual awareness reviewed previously predict that such activity should not give rise to visual experience. This prediction is reassuring, but can we be sure that it is correct? Reflection on the indirect nature of the evidence available to theorists of visual awareness makes it doubtful that we can confidently specify the minimum conditions for awareness, unless we are prepared to modify our everyday concept of consciousness. O'Regan and Noe have recently proposed a sophisticated redefinition of visual awareness along these lines. Progress at this frontier of visual neuroscience requires that scientists and philosophers join forces to clarify the concepts of experience and consciousness.
Mrs. J. is a 76-year-old woman who had been in good health. When she was brought to the hospital 10 days after being involved in an automobile accident, she was found to have severe brain injury and, despite vigorous treatment, has never regained consciousness. The consulting neurologist feels that she has no chance to recover completely and the "best case scenario" is that she may regain some consciousness without ever being able to take care of herself or probably without ever being able to interact with her environment in a meaningful fashion. She and her husband have been very close and had just celebrated their 50th wedding anniversary when the accident occurred. After long deliberation, her husband states that his wife had often said that "she would never want to live like this" and that she had always had a fear of being a burden to anyone. He wants active treatment stopped and asks that she only be kept comfortable and allowed to die. Their daughter agrees with this decision, although their son who lives in a distant state, feels that all treatment should continue and that she "certainly wouldn't be a burden." Among other considerations brought up by the husband is the fact that there are no financial arrangements to take care of long-term care in a nursing home.