SPECIAL CONSIDERATIONS
Cerebral Death: Persistent Vegetative State
Cerebral death, the so-called persistent vegetative state, refers
to cessation of the functions of the cerebral cortices. Brainstem functions governing
the respiratory centers, autonomic nervous system, endocrine system, and immune system,
which are vital for maintaining life, are preserved. Although the cortical EEG is
flat, it is usually contaminated by electromyographic activity of the forehead, a
sign of preservation of function of the facial nerve in the brainstem. The persistent
vegetative state represents irreversible loss of consciousness but not irreversible
loss of life or the mechanism of life; patients in this state can survive for months
or years. The term cerebral death is occasionally
used by mistake to indicate brain death, which includes the brainstem.
Cerebral death has not been accepted traditionally as equivalent
to death.[68]
However, some advocate that cerebral
death should be accepted as the death of individuals because the critical elements
of life are the organized cognition and "personhood" as the unique feature of human
life, which originate from the cerebrum.[69]
[70]
The problems with this notion are that the permanence of cerebral dysfunction cannot
be easily predicted in most clinical circumstances and threatens the severely senile
and severely retarded, who may have severely damaged high-brain functions.[70]
[71]
Of 40 patients referred to as being in the
persistent vegetative state, 17 (43%) were considered to be misdiagnosed; they were
aware of surroundings and able to communicate.[72]
The shortage of infant organs available for transplantation worldwide
has promoted a growing recognition of the potential use of anencephalics, who are
born without a forebrain and a cerebrum but with a rudimentary functional brainstem,
as donors.[73]
[74]
The natural course is that one half of the fetuses die in utero, and about 95% of
liveborn anencephalics usually die within 7 days.[74]
In 1995, the American Medical Association Council on Ethical and Judicial Affairs
supported the use of live anencephalic infants as organ donors.[73]
It claimed that anencephalic neonates are definitely different from individuals
who are in a persistent vegetative state, infants with profound neurologic injury,
and elderly adults with severe dementia, because anencephalics have no history of
consciousness and no possibility of ever being conscious. However, in 1996, it suspended
its opinion because of concern about certain diagnoses of anencephaly and understanding
of consciousness in these neonates.[75]
In 1961,
a kidney transplantation was first performed with an anencephalic newborn as a donor,
[76]
followed by some attempts of heart transplantation.
[77]
[78]
However,
Western countries, with the exception of Germany, consider an anencephalic infant
to be legally alive as long as the brainstem is functioning.[79]
[80]
This issue is still controversial.[73]
[74]
[81]
[82]
[83]
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