Authors: Sherwin B Nuland
How We Die (20 page)
Within a few years of Alzheimer’s paper, other workers reported on similar patients. In each case, the clinical course was not unlike that of Alzheimer’s original woman, and the autopsies revealed a diffuse atrophy which, while it involved the entire brain, was particularly evident in the cortex. On microscopic examination, great numbers of the senile plaques and fibrillary tangles could be demonstrated. By 1911, there had been twelve such additional reports.
The relative youth of some of the patients seemed to set the findings off from later descriptions of autopsies in which senile plaques and fibrillary tangles were being found in people of all ages and apparently with a variety of clinical histories. By 1929, there were four reports of the disease in patients below the age of forty, and even one whose symptoms began when he was seven. The problem may have been compounded by a certain selectivity in reporting—physicians are more likely to write up cases that seem unusual than those that are run-of-the-mill. Also, in those countries (and they are in the majority) where autopsies are not mandatory, by far the greater number are done on patients who are “interesting.” What is more interesting than a young man with an old man’s disease? Thus, by the late 1920s, the great majority of the many cases of Alzheimer’s disease in the world medical literature were patients in the relatively young fifty-to-sixty age group.
Although perceptive clinicians obviously appreciated that the age criteria continued to have fuzzy margins, the syndrome continued to be designated as Alzheimer’s presenile dementia for decades. That was the name by which I first encountered it in textbooks during my medical school years in the 1950s.
The process by which “Alzheimer’s presenile dementia” was transformed into the much more accurate “senile dementia of the Alzheimer type” is a tale paradigmatic of the way biomedical culture has evolved in the last third of the twentieth century. By this, I mean a combination of science, government involvement, and a factor that may best be understood by the term
consumer advocacy
. For sixty years following Alzheimer’s initial work, evidence slowly accumulated that there is little or no validity in differentiating between the senile and presenile forms of a disease when both are characterized by the same microscopic pathology. After the point was finally hammered home at a 1970 conference on Alzheimer’s and related conditions, there began to arise a scientific consensus that the persistence of such an arbitrary distinction was not only erroneous but misleading.
consumer advocacy
. For sixty years following Alzheimer’s initial work, evidence slowly accumulated that there is little or no validity in differentiating between the senile and presenile forms of a disease when both are characterized by the same microscopic pathology. After the point was finally hammered home at a 1970 conference on Alzheimer’s and related conditions, there began to arise a scientific consensus that the persistence of such an arbitrary distinction was not only erroneous but misleading.
One of the obvious effects of the changed attitude was the inclusion under the diagnostic umbrella of a perfectly huge population of elderly patients and their families. As research interests were spurred, scientists quite correctly began to clamor for more funding and sought it from government sources. In the United States, this meant the involvement of the National Institutes of Health (NIH) and the enlistment of every advocate of the elderly who might have some political influence. The creation of the National Institute on Aging (NIA) was the natural outgrowth of this process. The coordinating of the efforts of the scientists, the NIA, and caregivers resulted in the founding of the ADRDA. A malady thought in my medical school days to be so unusual that it was used as a trivia question in late-night study sessions had emerged as one of the leading causes of death in World Health Organization statistics. As a result of all the coordinated effort, the Alzheimer’s research budget in the United States in 1989 was some eight hundred times what it had been only ten years earlier.
In spite of the great progress that has been made during the last decade and a half in the care of patients and the support of those who must provide that care, the advancements in the more biomedical aspects of the disease, such as cause, treatment, and prevention, have not yet led to the discovery of any distinct cause of the disease, a method of curing it, or any way in which it might be prevented.
There is some evidence that there may be a genetic predisposition to Alzheimer’s, but it is less than convincing with regard to older patients and not yet satisfactorily proven for the younger, even though certain chromosomal defects have been identified in small numbers of people with the disease. Explorations into the effect of external factors such as aluminum and other environmental agents, viruses, head trauma, and decreased sensory input sometimes yield suggestive findings and other times do not. As in other maladies of obscure etiology, changes in the immune system have been studied without definitive outcome, and even that ubiquitous villain the cigarette has been suspected by some. What seems very likely is that there will prove to be a range of different pathways each of which leads eventually to the degenerative process of Alzheimer’s.
Certain physical and biochemical changes have been found to be accompaniments of the disease process, but their role is still unclarified. For example, biopsy of a patient’s cerebral cortex demonstrates a 60 to 70 percent decrease in levels of acetylcholine, a key factor in the chemical transmission of nerve impulses. In fact, attempts to find some effective treatment have focused to a large extent on the search for drugs that might improve the defects in neurotransmission.
Evidence has recently appeared to indicate that acetylcholine may have a role in regulating the body’s production of amyloid. It appears that amyloid increases when levels of acetylcholine are low. This finding provides a possible direct link between the chemical characteristics of the disease and its microscopic pathology, and it may lead to new methods of treatment. Especially provocative has been the suggestion that beta-amyloid is toxic to nerve cells; if this still-controversial idea can be substantiated, there will probably be some real reason for optimism in the search for effective therapy. To illustrate the degree of scientific controversy, it must be appreciated that neurobiologists continue to disagree over the question of whether amyloid causes the degeneration of nerve cells or is merely the result of the breakdown of those cells.
Also, a third microscopic characteristic has been added to the duo of fibrillary tangles and senile plaques, which is the presence within certain cells in the hippocampus of empty spaces called vacuoles, surrounding densely stained granules of uncertain significance.
Hippocampus
is the Greek word for seahorse, bestowed by the physicians of antiquity on this graceful curving structure within the temporal lobe of the brain because its elongated shape evoked the image of that peculiar animal. The hippocampus is involved with the storage of memories. Other of its functions have remained enigmatic, and no one is quite sure of the significance of the vacuoles and their contained granules.
Hippocampus
is the Greek word for seahorse, bestowed by the physicians of antiquity on this graceful curving structure within the temporal lobe of the brain because its elongated shape evoked the image of that peculiar animal. The hippocampus is involved with the storage of memories. Other of its functions have remained enigmatic, and no one is quite sure of the significance of the vacuoles and their contained granules.
And so the laboratory scientists remain puzzled and hard at work. It is difficult to believe, considering the vast amount of research being done and the many findings already being scrutinized, that the present state of knowledge is not the prelude to a period when the small discoveries will begin to coalesce into some very large ones. That is, after all, the way science usually works in this last third of the twentieth century, rather than by huge leaps forward.
Physicians are now at the point where they can make the diagnosis accurately in about 85 percent of cases without resorting to such extreme measures as biopsies of the brain. Among the several important reasons for early diagnostic efforts is the very direct one that there are certain treatable entities which exhibit enough of the characteristics of dementia that they may be confused with it, thereby compounding the tragedy. Among them are depression, medications, anemia, benign brain tumor, low thyroid function, and some of the reversible effects of trauma, such as blood clots pressing on the brain.
There are no consolations in the diagnosis of Alzheimer’s disease. The anguish may be mitigated by good nursing care, support groups, and the closeness of friends and family, but in the end it will be necessary for patient and loved ones together to walk through that very tortuous valley of the shadow, in the course of which everything changes forever. There is no dignity in this kind of death. It is an arbitrary act of nature and an affront to the humanity of its victims. If there is wisdom to be found, it must be in the knowledge that human beings are capable of the kind of love and loyalty that transcends not only the physical debasement but even the spiritual weariness of the years of sorrow.
VI
Murder and Serenity
M
AN IS AN
obligate aerobe”: There, stated with the simple directness of any of the most quoted aphorisms of ancient Hippocrates, stands the secret of human life. The dependence on air of all mankind, and indeed all known terrestrial animals, was recognized by primitive tribesmen long before any of them were distinguished from their fellows by being called healers. No matter the technological sophistication of ultramodern molecular research, and no matter the increasingly abstruse terminology of its current literature, the circle of knowledge always returns to its starting point: In order to live, man must have air.
AN IS AN
obligate aerobe”: There, stated with the simple directness of any of the most quoted aphorisms of ancient Hippocrates, stands the secret of human life. The dependence on air of all mankind, and indeed all known terrestrial animals, was recognized by primitive tribesmen long before any of them were distinguished from their fellows by being called healers. No matter the technological sophistication of ultramodern molecular research, and no matter the increasingly abstruse terminology of its current literature, the circle of knowledge always returns to its starting point: In order to live, man must have air.
In the late eighteenth century, it was found that not air in general but one particular component of it, oxygen, is the crucial factor on which life depends. The conception of man as an obligate aerobe then took on a more specific meaning: We have no choice—without oxygen, our cells die and we die with them. Oxygen absorption was soon thereafter shown to be the reason that the color of blood turns instantly from a dark tiredness to the bright red of vibrant life as it passes through the lungs; its departure into the cells of the body’s distant tissues was recognized as the cause of blood’s exhaustion when it returns depleted and blue from the long journey, figuratively gasping for air. Since then, the role of this most vital of nature’s elements has been explored generation after generation by thousands upon thousands of researchers, who have recorded their findings in virtually every one of the world’s written languages. Oxygen is at the focal point of the lens through which the sustaining processes of living things must be studied.
After all the years and all the research, the scholars of human biology come ever back to the few words that have always been inherent in an individual’s understanding of what he must do to stay alive: Man is an obligate aerobe. I could have plucked one of the many variations of that maxim from almost any of the past two centuries’ profusion of writings on the subject, but its actual source is instructive. I found it in a recent issue of the
Bulletin of the American College of Surgeons
, entitled “What’s New in Surgery—1992.” It appeared not as the time-honored nutshell of wisdom it is but as an experimentally proven, molecular-level certainty. What may be even more revealing are the statement’s surroundings; it is situated smack in the middle of the
Bulletin
’s highly technical article on the latest developments in critical care, that brand-new (the trendy term is
cutting edge
) superspecialty created to defend the very border of a desperately ill person’s flickering existence, the ultimate battleground contested between the strained forces of life and the powerful assaults that disease is launching in order to overwhelm them.
Bulletin of the American College of Surgeons
, entitled “What’s New in Surgery—1992.” It appeared not as the time-honored nutshell of wisdom it is but as an experimentally proven, molecular-level certainty. What may be even more revealing are the statement’s surroundings; it is situated smack in the middle of the
Bulletin
’s highly technical article on the latest developments in critical care, that brand-new (the trendy term is
cutting edge
) superspecialty created to defend the very border of a desperately ill person’s flickering existence, the ultimate battleground contested between the strained forces of life and the powerful assaults that disease is launching in order to overwhelm them.
The new specialty’s venue is the intensive care unit; its primary defensive strategy is to maintain a dependable supply of oxygen to the beleaguered cells of the body. Certainly our cave-dwelling forebears would have agreed that this is the right thing to do. The late Milton Helpern, to whose autopsy rooms patients were sent for study if the battle was lost, spent his career seeking out the “ten thousand several doors” to death, and he always came up with the same underlying answer: not enough oxygen.
Oxygen takes a remarkably direct route in making its way from the inhaled air to its ultimate destination, which is the aerobically obligated cell. After passing readily through the thin walls of the lung’s alveoli and their attached network of capillaries, the oxygen molecules link themselves to the protein pigment of the red cells which we call hemoglobin. Thereafter known as oxyhemoglobin, the combined molecules are carried from the lung to the left heart and then out through the aorta to the broad highways and narrow footpaths of the arterial circulation, until they reach the distant capillaries in the tissues whose sustenance is the object of their journey.
Once arrived, the oxygen separates itself from its traveling companion, hemoglobin. It leaves the red cell like a passenger getting off a railroad car, and enters the individual tissue cell along with biochemical substances required for that cell’s normal function. In what may be thought of as an exchange, carbon dioxide diffuses into the circulating blood, which also carries away the waste products of cellular life, to be destroyed or released through those magnificently multitalented organs of purification, the liver, the kidneys, and the lungs.
Like any good system of delivery and pickup, this one depends on a predictably consistent flow of traffic, in this case the traffic being blood.
Shock
is the term used to describe the course of events that ensues when the blood flow is inadequate to meet the needs of the tissues. Although shock may be caused by a variety of mechanisms, the majority of cases are due to failure of the heart’s pumping action (as in myocardial infarction) or to a major decrease in circulating blood volume (as in hemorrhage). The two mechanisms are called, respectively, cardiogenic and hypovolemic shock. Another common instigator of shock is septicemia, the entrance into the bloodstream of the products of infection. So-called septic shock has profound effects on cellular function, as will be discussed later, but one of its major actions is to induce a redistribution of blood so that it pools in certain extensive networks of veins, like those of the intestine, thereby becoming lost to the general circulation. Regardless of cause, all forms of shock have a similar outcome: Cells are deprived of their source of biochemical exchange and oxygen, the ultimate factor in their death.
Shock
is the term used to describe the course of events that ensues when the blood flow is inadequate to meet the needs of the tissues. Although shock may be caused by a variety of mechanisms, the majority of cases are due to failure of the heart’s pumping action (as in myocardial infarction) or to a major decrease in circulating blood volume (as in hemorrhage). The two mechanisms are called, respectively, cardiogenic and hypovolemic shock. Another common instigator of shock is septicemia, the entrance into the bloodstream of the products of infection. So-called septic shock has profound effects on cellular function, as will be discussed later, but one of its major actions is to induce a redistribution of blood so that it pools in certain extensive networks of veins, like those of the intestine, thereby becoming lost to the general circulation. Regardless of cause, all forms of shock have a similar outcome: Cells are deprived of their source of biochemical exchange and oxygen, the ultimate factor in their death.
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