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Persistent vegetative state
A persistent vegetative state (PVS) is a condition of patients with severe braindamage in whom comahas progressed to a state of wakefulness without detectable awareness. There is controversy in both the medical and legal fields as to whether this condition is irreversible. The syndrome was first described 1940 by Ernst Kretschmerafter whom it also has been called Kretschmer syndrome. (Das apallische Syndrom, in .Neurol.Psychiat, 169,576-579 (1940) The term was coined in 1972by ScottishneurosurgeonBryan Jennett and AmericanneurologistFred Plum to describe a syndrome that seemed to have been made possible by medicine's increased capacities to keep patients' bodies alive. [1] PVS is also known as corticaldeath, although it is not the same as comaor brain death. Patients in a persistent vegetative state are usually considered to be unconsciousand unaware. They are unresponsive to external stimuli, except, possibly, pain stimuli. Unlike coma, in which the patient's eyes are closed, patients in a vegetative state often open their eyes. They may experience sleep-wake cycles, or be in a state of chronic wakefulness. They may exhibit some behaviors that can be construed as arising from partial consciousness, such as grinding their teeth, swallowing, smiling, shedding tears, grunting, moaning, or screaming without any apparent external stimulus. Many patients emerge from a vegetative state within a few weeks, but those who do not recover within 30 days are said to be in a persistent vegetative state. The chances of recovery depend on the extent of injury to the brain and the patient's age, with younger patients having a better chance of recovery than older patients. Generally adults have a 50 percent chance and children a 60 percent chance of recovering consciousness from a PVS within the first 6 months. After a year, the chances that a PVS patient will regain consciousness are very low and most patients who do recover consciousness experience significant disability. The longer a patient is in a PVS, the more severe the resulting disabilities will be. Rehabilitation can contribute to recovery, but many patients never progress to the point of being able to take care of themselves. Few people have been reported to recover from PVS. Some authorities hold that PVS is, in fact, irreversible, and that the reportedly recovered patients were not suffering from true PVS. This conclusion is in dispute, however, as there have been cases like those of a man in Australia who was closely followed for years before suddenly 'waking up.' In the United States, it is estimated that there may be between 15,000-40,000 patients who are in a persistent vegetative state, but due to poor nursing home records exact figures are hard to determine.[{{fullurl:Template:FULLPAGENAME}}#endnote_uspvs] Nonetheless, some dispute still remains over the reliability of PVS diagnosis, particularly when a limited number of physicians (or physicians without experience in the area of PVS) make the diagnosis. One study of 40 patients in the United Kingdomconsidered that 43% of those patients classed as in a PVS were misdiagnosed and another 33% able to recover whilst the study was underway. [2]
Medical definitionTerminology in this area is somewhat confused. While the term 'persistent vegetative state' is the most frequent in media usage and legal provisions, it is discouraged by neurologists, who favour the use of the Royal College of Physicians (RCP)(1996) typology which refers only to the vegetative state, the continuing vegetative state, and the permanent vegetative state. This typology distinguishes various stages of the condition rather than using one term for them all. In his most recent book The Vegetative State, Jennett himself adopts this usage, on the grounds that "the 'persistent' component of this term...may seem to suggest irreversibility". The Australian National Health and Medical Research Council has suggested "post coma unresponsiveness" as an alternative term. Legal definitionAs opposed to brain death, PVS is not recognized as deathin any known legal system. This legal grey area has led to several court cases involving people in a PVS, those who believe that they should be allowed to die, and those who are equally determined that, if recovery is possible, care should continue. Well-known cases include Paul Brophy, Sunny von Bülowand Tony Bland, whose case created a precedent in the UK. The highly publicised case of Terri Schiavoin the United Statesinvolved disputes over a diagnosis of PVS given by several court-appointed doctors. Ultimately the court challenges were unsuccessful and Schiavo's feeding tubewas removed, leading to her subsequent death. References
Borthwick C (1996) The permanent vegetative state: ethical crux, medical fiction? Issues Law Med. 1996 Fall;12(2):167-85. Fulltext on author's website (Author questions the validity of most PVS diagnoses, and the validity of the basic nosology.)
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This article contains text from the NINDS public domain pages on TBI at http://www.ninds.nih.gov/health_and_medical/disorders/tbi_doc.htmand http://www.ninds.nih.gov/health_and_medical/pubs/tbi.htm de:Apallisches Syndrom ja:??????? nl:Coma vigil ru:???????????? ????????? Categories: Neurology
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