K_Z
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Sorry to trouble you, but could you or someone else provide a link to the comments of "Dr. G" referenced in sentence two above? I'm looking for a way to help a friend understand why I'm so insistent that there is no recovery from brain death and that pretty much would put in pretty raw terms. It sounds similar but not identical to something else I had read. Thank you.
I'm not nore, and I don't have a link for Dr. G., but this article is easy to read, and quite clear about the changes in the brain that occur in brain death with prolonged ventilation. It's beautifully written by a procurement and transplant surgeon. (Warning- may be disturbing to some readers.) I have linked this here before.
http://www.vqronline.org/essay/dead-enough-paradox-brain-death
The truth in brain death is mind-boggling. While normal brain tissue is firm, a brain that has been dead shows progressive autolysis, a form of biological self-destruction. It will almost be like soup, Dr. Harry Vinters, chief of neuropathology at UCLA, recently explained to me. He is the co-author of a major textbook on the pathology of the brain and has performed almost a hundred autopsies on the brain-dead. It really depends on how long they have been on the ventilator. If they have been on the ventilator for two days, then the brain is grey and softened. But if, for example, a family has had difficulty deciding what they want to do and the patient has been kept on the ventilator for two to three weeks, then theres tremendous autolysis. The brain gets very swollen, soft, and mushy. The nerve tissue can become so friable that fragments of brain from the head will break off and float down the spinal column. Sometimes Ill be looking at a slide of the spinal cord, says Vinters, and Ill see fragments of cerebellum floating around in the specimen.
And this article discusses hypoxic ischemic encephalopathy (HIE), and the subsequent liquefaction of brain tissue in "respirator brain" situation (prolonged ventilation in a brain dead person).
Severe and protracted HIE damages the cortex, deep nuclei, and brainstem, resulting in brain death. If such a patient is put on the respirator, the brain (under normal body temperature) undergoes an enzymatic autodigestion which may end in liquefaction. The term" respirator brain" that has been applied in such cases is misleading because the autolysis is not caused by the respirator. The term "non-perfused brain" is more accurate. Because circulation is arrested and all metabolic activity ceases, the non-perfused brain does not show any reactive changes (inflammation, macrophages, gliosis), only autolysis. Imaging reveals hypodensity due to edema and disintegration of brain tissue without enhancement.
http://neuropathology-web.org/chapter2/chapter2aHIE.html
This picture, from the above article, demonstrates no blood flow to any brain structures within the cranium.
http://neuropathology-web.org/chapter2/images2/2-nonperfused.jpg
http://www.sciencedirect.com/science/article/pii/S004681777380067XCausal factors in the development of brain death in respirator patients were analyzed in the present study. The syndrome, as manifested in the cases studied, is characterized by irreversible deterioration of nervous system function, with deepening coma and loss of electroencephalographic activity and, pathologically, by severe brain edema and softening, often with diffuse liquefaction necrosis.