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A persistent vegetative state (PVS) is a condition of patients with severe brain damage in whom coma has 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 Kretschmer after whom it also has been called Kretschmer syndrome. (Das apallische Syndrom, in .Neurol.Psychiat, 169,576-579 (1940)
The term was coined in 1972 by Scottish neurosurgeon Bryan Jennett and American neurologist Fred 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 cortical death, although it is not the same as coma or brain death.
Patients in a persistent vegetative state are usually considered to be unconscious and unaware. 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. They are unresponsive to external stimuli, except, possibly, pain stimuli. 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. In the United States, it is estimated that there may be as many as 15,000 patients who are in a persistent vegetative state.[2]
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 Kingdom considered that 43% of those patients classed as in a PVS were misdiagnosed and another 33% able to recover whilst the study was underway. [3]
Legal definition
As opposed to brain death, PVS is not recognized as death in 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 Bülow and Tony Bland, whose case created a precedent in the UK. The media circus case of Terri Schiavo in the United States is an example of PVS, having been so diagnosed by multiple court-appointed physicians. A dispute of this diagnosis was a major issue in a lengthy and unsuccessful court challenge.
The Schiavo case was governed by Florida Law, under which the legal definition of "PVS" is:
- (12) "Persistent vegetative state" means a permanent and irreversible condition of unconsciousness in which there is:
- (a) The absence of voluntary action or cognitive behavior of any kind.
- (b) An inability to communicate or interact purposefully with the environment.
This legal definition is found in State Law 765.101(12). [4]
Reference
- Jennett B, Plum F. (1972). Persistent vegetative state after brain damage. A syndrome in search of a name. Lancet 1 (7753), 734–737. PMID 4111204.
- Multi-Society Task Force on PVS (1994). Medical aspects of the persistent vegetative state. N Engl J Med (330), 1499–508. PMID 7818633, PMID 8177248.
- 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.)
- Andrews K, Murphy L, Munday R, Littlewood C. (1996). Misdiagnosis of the vegetative state: retrospective study in a rehabilitation unit. BMJ (313), 13–16. PMID 8664760, fulltext.
External links
Notes
- ↨ Hirsch, Joy. (May 2, 2005). "Raising consciousness". The Journal of Clinical Investigation. American Society for Clinical Investigation. 115(5): 1102.
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