A persistent vegetative condition ( PVS ) is a conscious disorder in which patients with severe brain damage are in a state of partial passion rather than true consciousness. After four weeks in a vegetative state (VS), patients were classified as being in a persistent vegetative state. The diagnosis is classified as a permanent vegetative state several months (3 in the US and 6 in the UK) after non-traumatic brain injury or one year after traumatic injury. Today, more doctors and neurologists prefer to call the state of consciousness an unresponsive syndrome of consciousness, mainly because of the ethical question of whether a patient can be called "vegetative" or not.
Video Persistent vegetative state
Definisi
There are several different definitions according to technical use versus layman. There are different legal implications in different countries.
Medical definition
A conscious state of consciousness lasting more than a few weeks is called a persistent (or 'sustainable') vegetative state.
Lack of legal clarity
Unlike brain death, permanent vegetative status (PVS) is recognized by laws as deaths in very few legal systems. In the US, the court has requested a petition before the cessation of life support indicating that the restoration of cognitive function over the vegetative state is judged as unlikely by authoritative medical opinion. In England and Wales legal precedents for clinical assisted withdrawal of nutrients and hydration in the case of patients in PVS were established in 1993 in the case of Tony Bland, who suffered an anoxic catastrophic brain injury in the 1989 Hillsborough disaster. An appeal to the Protection Court is now still required before nutrition and hydration may be withdrawn or retained from PVS patients (or 'minimally conscious' patients - MCS).
This gray area of ​​law has led to vocal supporters that those in the PVS should be left to die. Others are equally determined that, if recovery is entirely possible, care should be continued. The existence of a small number of cases of diagnosed PVS that ultimately result in improvements makes defining recovery as "impossible" very difficult in the legal sense. These legal and ethical issues raise questions about autonomy, quality of life, proper use of resources, the wishes of family members, and professional responsibility.
Vegetative Condition
The vegetative state is a chronic or long-term condition. This condition is different from a coma: coma is a state that has no awareness and awake. Patients in a vegetative state may have awakened from a coma, but are still not conscious again. In patients the vegetative state can open their eyelids occasionally and show a sleep-wake cycle, but it has absolutely no cognitive function. The vegetative state is also called "coma vigil". The likelihood of regaining consciousness diminishes significantly as the time spent in the vegetative state increases.
Persistent vegetative conditions
Persistent vegetative status is the use of a standard (except in the UK) for medical diagnosis, which is performed after various neurological and other tests, caused by extensive and irreversible brain damage that the patient has never achieved higher. function above the vegetative state. This diagnosis does not mean that doctors have diagnosed repairs as unlikely, but opens the possibility, in the US, for a judicial request to end life support. Informal guidelines state that this diagnosis can be done after four weeks in a vegetative state. US Caselaw has shown that a successful petition for cessation has been made after the diagnosis of a persistent vegetative state, although in some cases, such as that of Terri Schiavo, the ruling has generated widespread controversy.
In the UK, the term 'persistent vegetative state' is not recommended because two more precisely defined terms are highly recommended by the Royal College of Physicians (RCP). The guidelines recommend the use of sustainable vegetative conditions for patients in a vegetative state for more than four weeks. The medical definition of a permanent vegetative state can be made if, after thorough testing and customary 12-month observation, medical diagnosis is impossible by the medical expectation that the mental state will improve. Therefore, a "continuous vegetative state" in the UK can remain a diagnosis in cases to be called "persistent" in the US or elsewhere.
While the actual test criteria for a "permanent" diagnosis in the UK are very similar to the criteria for "persistent" diagnosis in the US, semantic differences give in the UK legal assumptions that are commonly used in court applications to end life support. The UK diagnosis is generally only done after 12 months of observing the static vegetative state. The diagnosis of persistent vegetative state in the US usually still requires applicants to prove in court that recovery is not possible by informed medical opinion, whereas in the UK a "permanent" diagnosis has given the applicant this presumption and may make the legal process less time consuming.
In common usage, the definitions of "permanent" and "persistent" are sometimes combined and used interchangeably. However, the acronym "PVS" is intended to define a "persistent vegetative state", without the need for the connotation of immortality, and is used as such throughout this article.
Bryan Jennett, who originally coined the term "a persistent vegetative state," now recommends the continuous and permanent use of the British division in his latest book The Vegetative State. This is one for precision purposes, arguing that the "persistent 'component' of this term... may seem to suggest irreversibility".
The National Health and Medical Research Council of Australia has suggested "post coma unresponsiveness" as an alternative term for "vegetative states" in general.
Maps Persistent vegetative state
Signs and symptoms
Most PVS patients are unresponsive to external stimuli and their conditions are associated with different levels of consciousness. A certain level of consciousness means that a person can still respond, in varying degrees, to stimuli. Someone in a coma, however, can not. In addition, PVS patients often open their eyes in response to feeding, which must be done by others; they are capable of swallowing, while the patient in the coma lives with the eyes closed (Emmett, 1989).
The eyes of a PVS patient may be in a relatively fixed position, or trace a moving object, or move in a disconjugate way (ie, completely out of sync). They may experience sleep-wake cycles, or are in a chronic wakeful state. They may show some behaviors that can be interpreted as arising from partial consciousness, such as gnashing of teeth, swallowing, smiling, shedding tears, snorting, moaning, or screaming without any obvious external stimulus.
Individuals in PVS are rarely in life-sustaining equipment other than the brainstem filled tubes, vegetative function centers (such as heart rate and rhythm, respiration, and gastrointestinal activity) are relatively intact (Emmett, 1989).
Recovery
Many people appear spontaneously from the vegetative state within a few weeks. Recovery opportunities depend on the extent of brain injury and the age of younger patients have a better chance of recovery than older patients. A 1994 report found that of those in the vegetative state a month after the trauma, 54% had recovered a year after the trauma, while 28% died and 18% were still in the vegetative state. But for non-traumatic injuries such as stroke, only 14% had recovered consciousness at one year, 47% had died, and 39% were still vegetative. Vegetative patients six months after the initial incidence were much less likely to recover consciousness a year after the incident than in the case of those reported only vegetatively at one month. The New Scientist article from 2000 provides a pair of charts showing changes in patient status during the first 12 months after a head injury and after an incident that robs the brain of oxygen. After a year, the chances of a PVS patient will regain very low and most patients who recover consciousness experience significant disability. The longer a patient in the PVS, the more likely the defect is produced. Rehabilitation can contribute to recovery, but many patients never advance to the point to be able to take care of themselves.
There are two dimensions of recovery from a persistent vegetative state: recovery of consciousness and function recovery. Recovery of consciousness can be verified by reliable evidence of self-awareness and the environment, consistent voluntary behavior responses to visual and auditory stimuli, and interaction with others. Recovery function is characterized by communication, ability to learn and to perform adaptive tasks, mobility, self-care, and participation in recreational or vocational activities. Recovery of consciousness can occur without functional recovery, but functional recovery can not occur without awareness recovery (Ashwal, 1994).
Cause
There are three main causes of PVS (persistent vegetative state):
- Acute traumatic brain injury
- Non-traumatic: neurodegenerative disorders or brain metabolic disorders
- Severe congenital anomalies in the central nervous system
Medical books (such as Lippincott, Williams, and Wilkins) (2007) In A Page: Pediatric Signs and Symptoms) describe some of the potential causes of PVS, which are as follows:
- Bacterial, viral, or fungal infections, including meningitis
- Increased intracranial pressure, such as tumors or abscesses
- Vascular pressure that causes intracranial hemorrhage or stroke
- Hypoxic ischemic injury (hypotension, cardiac arrest, arrhythmia, almost drowning)
- Toxins such as uremia, ethanol, atropine, opiates, lead, colloidal silver
- Trauma: concussion, bruising
- Seizure, nonconvulsive status epilepticus and postconvulsive state (postiktal status)
- Electrolyte imbalances, involving hyponatremia, hypernatremia, hypomagnesemia, hypoglycemia, hyperglycemia, hypercalcemia, and hypocalcemia
- Post-infection: Acute disseminated encephalomyelitis (ADEM)
- Endocrine disorders such as adrenal insufficiency and thyroid disorders
- Degenerative and metabolic diseases including urea cycle disorders, Reye syndrome, and mitochondrial disease
- Systemic infection and sepsis
- hepatic encephalopathy
In addition, the authors claim that doctors sometimes use AEIOU-TIPS mnemonic devices to remember part of the differential diagnosis: Alcohol intake and acidosis, Epilepsy and encephalopathy, Infection, Opiates, Uremia, Trauma, Overdose or insulin inflammatory disorders, Poisoning and psychogenic cause, and Shock.
Diagnosis
Although convergent convergent on the definition of a persistent vegetative state, recent reports have raised concerns about the accuracy of diagnosis in some patients, and the extent to which, in some cases, residual cognitive function may remain undetectable and patients diagnosed in a persistent vegetative state. Objective assessment of residual cognitive function can be very difficult because the motor response may be minimal, inconsistent, and difficult to document in many patients, or may be undetectable to others because no cognitive output is possible (Owen et al., 2002). In recent years, a number of studies have demonstrated an important role for functional neuroimaging in the identification of residual cognitive function in a persistent vegetative state; this technology provides new insights into brain activity in patients with severe brain damage. Such studies, when successful, may be particularly useful when there is concern about the accuracy of the diagnosis and the likelihood that residual cognitive function remains undetectable.
Diagnostic experiments
Researchers have begun using functional neuroimaging studies to study implicit cognitive processes in patients with a clinical diagnosis of a persistent vegetative state. Activation in response to sensory stimuli with positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and electrophysiological methods can provide information about the presence, degree, and location of any residual brain function. However, the use of this technique is in people with severe methodological, clinical, and theoretical brain damage and requires careful quantitative analysis and interpretation.
For example, PET research has shown identification of residual cognitive function in a persistent vegetative state. That is, external stimulation, such as a painful stimulus, still activates the "primary" sensory cortex in these patients but this area is functionally cut off from the "higher" associative areas needed for consciousness. These results suggest that the cortical portions are still functioning in "vegetative" patients (Matsuda et al., 2003).
In addition, other PET studies have revealed consistent and consistent responses in areas that the auditory cortex predicts in response to understandable speech implications. In addition, the initial fMRI examination revealed a partial response to semantic ambiguous stimuli, which are known to tap into the higher aspect of speech understanding (Boly, 2004).
In addition, several studies have used PET to assess the treatment of malignant somatosensory stimuli centers in patients in PVS. Malignant somatosensory stimulation is activated midbrain, the contralateral thalamus, and primary somatosensory cortex in each PVS patient, even in the absence of detectable cortical potential. In conclusion, somatosensory stimulation of PVS patients, on pain-inducing intensity of control, results in increased neuronal activity in the primary somatosensory cortex, even if resting brain metabolism is severely impaired. However, this primary cortical activation appears to be isolated and separated from the corticative associations of high levels (Laureys et al., 2002).
Also, there is evidence of some functional brain regions in the brain that are tragically injured. To study five patients in PVS with different behavioral features, researchers used PET, MRI and magnetoencephalographic (MEG) responses to sensory stimulation. In three of the five patients, co-registered PET/MRI correlated areas of brain metabolism that were relatively preserved with isolated fragments of behavior. Two patients experienced anoxic injury and showed a significant reduction in overall brain metabolism up to 30-40% of normal. Two other patients with non-anoxic, multifocal brain injury showed some isolated brain regions with higher metabolic rates, which ranged up to 50-80% from normal. Nevertheless, their global metabolic rate remains & lt; 50% of normal. MEG records of three PVS patients provide clear evidence for the absence, abnormality or reduction of responses. Despite the major abnormalities, however, these data also provide evidence for localized residual activity at the cortical level. Each patient partially maintains a limited sensory representation, as evidenced by a slow-evoking magnetic field and gamma band activity. In two patients, this activation correlated with isolated patterns of behavior and metabolic activity. The remaining active areas identified in three PVS patients with behavioral fragments appear to consist of separate corticothalamic tissues that retain partial functional connectivity and integrity. A single patient suffering severe injury to the tegmental mesencephalon and paramedian thalamus showed broadly preserved cortical metabolism, and a global average metabolic rate of 65% of normal. The relatively high preservation of cortical metabolism in these patients determines the first functional correlation of clinical-pathological reports linking permanent unconsciousness to structural damage to these areas. The specific patterns of metabolic activity preserved identified in these patients reflect new evidence of the modular nature of the individual functional tissues that underlie conscious functioning of the brain. Variations in cerebral metabolism in chronic PVS patients show that some cerebral regions may retain partial function in the catastrophically injured brain (Schiff et al., 2002).
Diagnostic error
The statistical PVS missiagnosis is not uncommon. An example study with 40 patients in the UK reported 43% of their patients who were classified as PVS were believed to be the case and another 33% had recovered during the study. Some cases of PVS can actually be misdiagnosed if the patient is in a minimally undiagnosed conscious state. Because the precise diagnostic criteria of a minimally conscious state were only formulated in 2002, there may be chronic patients diagnosed as PVS before the secondary idea of ​​a minimally conscious state becomes known.
The presence or absence of conscious awareness with the patient's vegetative condition is a prominent problem. Three different aspects of this must be distinguished. First, some patients may become aware only because they are misdiagnosed (see above). In fact, they are not in a vegetative state. Secondly, sometimes a patient is diagnosed correctly but then checked during the early stages of recovery. Third, perhaps one day the idea of ​​vegetative states will change to include elements of conscious awareness. The inability to describe these three examples causes confusion. An example of such confusion is a response to recent experiments using functional magnetic resonance imaging which reveals that a woman diagnosed with PVS is able to activate a predictable part of her brain in response to an examiner's request that she imagines herself playing tennis or moving from the room. to the room in his house. Brain activity in response to these instructions can not be distinguished from healthy patients.
In 2010, Martin Monti and his fellow researchers, working at the MRC Cognition Unit and Brain Sciences at Cambridge University, were reported in an article in the New England Journal of Medicine that some patients in a persistent vegetative state respond to verbal instructions with show different brain activity patterns on fMRI scan. Five of a total of 54 diagnosed patients seem to be able to respond when instructed to think about one of two different physical activities. One of these five is also able to "answer" yes or no questions, again by imagining one of these two activities. It is not clear, however, whether the fact that part of the patient's brain is on in fMRI can help these patients make their own medical decisions.
In November 2011, a publication on The Lancet featured bedside EEG equipment and showed that the signal could be used to detect consciousness in three of 16 patients diagnosed in a vegetative state.
Treatment
There is currently no treatment for vegetative state that will meet the criteria of evidence-based drug efficacy. Several methods have been proposed that can be divided into four categories: pharmacological methods, surgery, physical therapy, and various stimulation techniques. Pharmacological therapy primarily uses active substances such as tricyclic antidepressants or methylphenidate. Mixed results have been reported using dopaminergic drugs such as amantadine and bromocriptine and stimulants such as dextroamphetamine. Surgical methods such as deep brain stimulation are used less frequently because of invasive procedures. Techniques of stimulation include sensory stimulation, sensory regulation, music and musicokinetic therapy, social-tactile interaction, and cortical stimulation.
Zolpidem
There is limited evidence that the hypnotic drug zolpidem has an effect. The results of several scientific studies that have been published so far about the effectiveness of zolpidem have been contradictory.
Epidemiology
In the United States, it is estimated that there may be between 15,000 and 40,000 patients who are in a persistent vegetative state, but due to poor nursing home records, the exact figure is difficult to determine.
History
This syndrome was first described in 1940 by Ernst Kretschmer who called it apallic syndrome. The term persistent vegetative state was created in 1972 by Scottish spinal surgeon Bryan Jennett and American neurologist Fred Plum to describe the syndrome that seems to have been made possible by the increase in drug capacity to keep the patient's body alive.
Society and culture
Ethics and policies
The ongoing debate is about how much care, if any, the patient in a persistent vegetative state should receive in a health system that is plagued by limited resources. In the case before the New Jersey High Court, Betancourt Hospital v. Trinity , a community hospital looking for the decision that dialysis and CPR for such patients is a futile treatment. An American bioethicist Jacob M. Appel argues that the money spent on treating PVS patients would be better spent on other patients with a higher chance of recovery. The patient died naturally before the decision in the case, so the court found the issue moot.
In 2010, British and Belgian researchers reported in an article in the New England Journal of Medicine that some patients in a persistent vegetative state really have enough awareness to "answer" yes or no questions on scan fMRI. However, it is unclear whether the fact that part of the patient's brain is on in fMRI will help these patients make their own medical decisions. Professor Geraint Rees, Director of the Institute of Cognitive Neuroscience at University College London, responded to the study by observing that, "As a physician, it is important to satisfy yourself that the person you are communicating is competent to make that decision.It is too soon to conclude that someone capable of answering 5 of 6 yes/no questions is fully conscious like you or me. "In contrast, Jacob M. Appel from Mount Sinai Hospital told the Telegraph that this development could be a welcome move to clarify the patient's wishes. Appel stated: "I see no reason why, if we really believe such patients communicate, people should not respect their wishes.Even, as a doctor, I think an interesting case can be made that doctors have an ethical obligation to help. that by removing treatment I suspect that, if such people are trapped in their bodies, they may live in severe torture and will require that their treatment be stopped or even active euthanasia. "
Important case
See also
- Anencephaly
- Brain death
- Botulism
- Catatonia
- Karolina Olsson
- Syndrome is locked
- Process-oriented Coma Work, for an approach to work with residual awareness in patients in comatose and sedentary vegetation conditions
References
This article contains the text of the NINDS public domain page in TBI. [1] and [2].
Further reading
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SarÃÆ', M.; Sacco, S.; Cipolla, F.; Onorati, P.; Scoppetta, C; Albertini, G; Carolei, A (2007). "Unexpected recovery from a permanent vegetative state". Brain Injury . 21 (1): 101-103. doi: 10.1080/02699050601151761. PMID 17364525. - Canavero S, et al. (2009). "Recovery of consciousness after stimulation of the bifocal extradural cortex in permanent vegetative patients". Journal of Neurology . 256 (5): 834-6. doi: 10.1007/s00415-009-5019-4. PMID 19252808.
- Canavero S (editor) (2009). Therapeutic cortical stimulation textbook . New York: Nova Science. ISBN: 9781606925379. CS1 maint: Additional text: author list (link)
- Canavero S, Massa-Micon B, Cauda F, Montanaro E (May 2009). "Recovery of induced cortical-induced-extracorptive induction induction in permanent post-traumatic vegetative state". A Neurol . 256 (5): 834-6. doi: 10.1007/s00415-009-5019-4. PMID 19252808.
- Connolly, Kate. The victim of a car accident trapped in a coma for 23 years was conscious, The Guardian , November 23, 2009.
- Machado, Calixto, et al. The Cuban Perspective on Persistent Vegetative State Management. MEDICC Review 2012; 14 (1): 44-48.
Source of the article : Wikipedia
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