On Aging, Dementia, and the Catholic Physician
At the time of Shakespeare, the perspective of a “second childhood,” melancholy and all, was a rare one. The life span of men was at the time several years–or even decades–shorter, and thus few ever reached the “last scene of all” of which Lord Jacques tells us. In recent years, by contrast, the steady increase in life expectancy has turned late aging in a commonly experienced phenomenon. Indeed, just in the United States over three million people can boast of having seen World War I, and the number of persons aged 85 or older is predicted to continue to increase towards the beginning of the next century.
In industrialized countries, this remarkable trend compounds a severe drop in birth rates, largely due to artificial contraception and systematic killing of the young through abortion, giving origin to a phenomenon known as population aging. In short, this means that the proportion (or ratio) of the young to the old is becoming a smaller and smaller number. It should not be surprising then that funding institutions and governments have taken an interest in research oriented to unravel the mysteries of aging. This quest was branded in a recent review published in the highly prestigious journal Science as “The Search for Methuselah,” and spans from genetic studies in flies, through molecular biology of worms, studies on aging rodents and monkeys, and studies of the human brain. In its most radical form, these scientific endeavors aspire to the arrest of the process of aging. More moderate scientists content themselves with:
...discovering ways to block age-related disorders of higher cortical function without necessarily prolonging life [so as to] enable many of the elderly to remain independent and enjoy life well beyond the eighth decade. 1
By “disorders of higher cortical function” the author refers to a series of changes in cognitive ability such as slowing in problem solving and other intellectual processing, as well as mild to moderate decreases in memory, all of which are common in normal aging. When these changes accelerate, they lead to “impaired memory, judgment, abstraction and language,” a picture known to physicians as dementia.
The Problem of Dementia: Its Magnitude
How common is dementia? Although numbers vary slightly from one study to another, there is by now solid evidence showing that the prevalence of dementia increases in each decade of life after age 60, from about 4 cases in 1,000 at age 60 to more than 20% at ages 85 or older.1 Although sometimes the symptoms are due to reversible, treatable causes (e.g.: medication side effects, lack of certain vitamins, metabolic imbalances, certain brain tumors and infections, or blood clots on the inner side of the skull pressing on the brain from the outside) this occurs in only about 5% of all cases. In all the rest, dementia is caused by diseases having distinct processes that result in specific and excessive irreversible deterioration of certain parts of the brain.
Alzheimer’s disease accounts for over 60% of about 4 million cases of dementia currently in the United States, and has thence been the focus of much attention by basic scientists, epidemiologists and clinicians. Its importance for public health is so big that it led to the creation of a special Advisory Panel, mandated by law to report before Congress between 1989 and 1992. This Panel was charged with reporting on the progress made on the field as well as with suggesting public policies oriented to ameliorate it.2 With the increasing aging of society the number of cases of dementia will continue to increase, concomitantly increasing the already staggering cost, both personal and societal of the illness. One of the notable features of this disease is that it affects people of all ethnic, cultural and racial heritages and of all socio-economic conditions.2 However, some protection appears to be afforded by education, since more educated people seem to have a lower risk of becoming ill (this “protective effect” from continued intellectual activity is not well understood, but it can be interpreted in the light of classical psychology as explained below).
But, What Is Alzheimer’s Disease? A Few Precisions
Alois Alzheimer was a nineteenth century French neuropa-thologist who first described the most common of the dementias, which now is named after him. He noticed that when a patient showed severe senile deterioration early in adult life, his or her brain was full of abnormal structures that were described by their microscopical appearance as neurofibrillary tangles and senile plaques. Since Alzheimer’s time, it has become generally accepted that the same abnormal process accounts for senile deterioration at later stages of life. The progressive accumulation of those plaques and tangles leads, by a mechanism which remains largely unclear, to the death of numerous nerve cells (neurons) in regions of the brain associated with memory and integration of experience. The loss of those neurons eventually results in the classical, astounding picture of a
...person whose ability to walk, eat and have sensations is essentially unaffected, but who cannot make sense of the world,1
and who
...progressing beyond the initial phases of forgetfulness...ultimately ...becomes entirely helpless, losing control over bodily functions, incapable of self-help.2
This progression in the degree of incapacitation, with the concomitant increase in reliance upon caregivers, usually takes 6 to 8 years (although periods of illness as long as 20 years have been reported).2
Alzheimer’s disease is at least partly inherited, but attempts at identifying a single gene, or even a few, responsible for that inheritance have been unsuccessful or not easy to reproduce. There are several technical explanations for that fact, which are however out of the scope of this commentary. Nonetheless, some associations between inheritance of specific genes and transmission of the disease have been reported in familial cases, although the genes seem to be different in different families.2 Many molecular abnormalities have been found in the brains of patients with Alzheimer’s disease, but it would seem that the foremost difference between senile dementia and normal aging is the speed at which each occurs, the former being much faster. Thus, the brain of a 90-year-old person deceased after keeping all his intellectual faculties in full power also contains abnormal structures typical of Alzheimer’s dementia, but in much smaller numbers. A host of other facts of the same nature could be pointed out, like the reduction in numbers of neurons, or accumulations of defects in the molecules that contain genetic information (so called nucleic acids), both of which are also present in normal aging. Evidence on what bearing all these multiple anatomic and functional age-related changes have on the mind in normal people is generally lacking, and a leading scientist in the field, Dennis Selkoe (in his article already quoted) thinks that:
In many people the answer may be ‘very little.’1
One important recent development in the medical aspects of Alzheimer’s disease has been the development of a very easy diagnostic test (consisting simply on a modified eye exam) which allows sure identification of the illness, by showing an exaggerated response to pharmacologic stimulation. This is an important step, since diagnosis of Alzheimer’s could only be accomplished by very invasive testing up to now.
Browsing Psychology On Mind and Brain
In any case, the question remains as to what is known about the relationship between the faculties of the mind and the brain. This fascinating problem has a history as long as that of philosophy. Already the early Greek thinkers devoted writings to it, which were critically reviewed and structured in a complete theory by Aristotle of Stagyra. Aristotelian psychology forms the backbone of the school known as moderate realism, but also of modern empiricism and to some extent of modern phenomenology, so it seems appropriate to turn now to a brief description of its main features in order to properly address this question.
First, it is worth pointing out that for Aristotle, psychology is the part of Physics (i.e., it is concerned with natural objects), being dedicated in particular to study those natural objects which are alive. The Philosopher approaches the problem by describing the four kinds of causes or explanations of living things. In fact:
...causes are spoken of in four senses. In one sense, they say the substance, or the essence, is the cause (...); in another, it is the matter or the underlying subject; in a third, the source which begins the motion; and in the fourth (...), the final cause or the good (for this is the end of every generation and every motion).3
The soul is the cause and principle of a living body (...) in three specified senses of “cause”... as a source of motion, and as final cause, and as the substance of the animated body.4
Natural substances are composites of matter and form, and the proper definition of the soul is then:
...the first actuality of a natural body which has organs,5
...the latter (i.e., the natural organic body) being the fourth (material) cause.
The simplest such form is the nutritive soul, which is the form of plants. Complexity is added in the form of animals by the addition of the powers of sensation, imagination and memory. Finally, in man, intellect is added. To each of these powers belongs a moving cause; nutrition, assimilation and growth are the movers in plants; desire and locomotion in animals; and in man also thought and the cause of thought the active intellect, which:
...alone can be separated from the body, just as that which is eternal can be separated from that which is destructible6.
If only the active intellect can be separated from the body, it follows that all other powers of the soul are properties of the composite, and hence cannot operate in a defective organ. The same is true regarding the affections of the soul, like meekness, fear, pity, gladness, love and hate, which exist with the body and indeed are:
...forms subsisting in the matter.7
St Thomas Aquinas comments on this point as follows:
From these follow two clarifications: one, that understanding is an operation proper to the soul which does not require the body except as its object (...) whereas seeing, and other properties and operations belong not only to the soul, but to the composite. The second, that that which contains in itself the operation contains also the act of being (esse) and the subsistence (...) Therefore, the intellect is a subsistent form, whereas all of the other powers are forms in the matter. (emphasis mine)8
...and subject to corruption and disease (emphasis mine).
Thus, sensation, imagination, memory and the elementary operations of the passive intellect which have the brain (and the nervous system in general) as their organ, would not be possible when the brain is severely ill. When this occurs, the integration of experience is severely disrupted, giving rise to illnesses which can affect primarily memory (amnesia), primarily perception (agnosia), primarily language (aphasia) or primarily the execution of planned motor behavior (apraxia). When all of the above functions are affected simultaneously, dementia ensues.
Experience is the Bridge Between Memory and Intellect
How is experience integrated? This problem, which has been the focus of much attention recently as a consequence of the so-called “neuroscience revolution,” has also been extensively dealt with by several philosophical schools, including moderate realism. Aristotle speaks about it in the beginning of Metaphysics:
All animals, except men, live with the aid of appearances and memory, and they participate but little in experience; but the race of men lives also by art and judgment. In men, experience comes into being from memory, for many memories of the same thing result in the capacity for one experience. And experience seems almost similar to science and art, but science and art come to men through experience.9
Thus, the Philosopher understands experience as a certain habitual knowledge originated mostly through the senses, which becomes the source of theoretical abstractions (arts and science) through inductive reasoning. Perhaps not so surprisingly this notion is largely shared by modern empiric scientists of materialistic extraction (who discuss it under the general label of “consciousness”). For example, Michael Posner, in an article published late last year in the very prestigious Proceedings of the National Academy of Sciences USA, argues that “an understanding of consciousness” should be pursued by appreciating the way the human brain achieves:
...selection of sensory information, activa[tion] of ideas stored in memory, and maintain[ance] of an alert state.10
Along the same lines, the Nobel Prize Winner Francis Crick–a hard core materialist–has argued that consciousness is synonymous with awareness, whether of objects on the external world or of internal concepts, and entails the operation of a mechanism combining attention and memory.11
In fact, if consciousness is equated with experience as a vital actuality, the conclusions of modern research fully confirm Aristotle’s speculation. However, experience is not only a vital actuality but also a cognitive habit, as explained before. This concept is further developed by St. Thomas Aquinas, who specifies the power (or faculty) by which such habit is acquired: the cogitative. Operation of the cogitative power is intellectual in that it entails a certain practical judgment regarding perception and memory (e.g., if it has happened before, to which kind it belongs, and so on). However, its operation occurs in the composite (we know now that in fact its organ is the brain), and in consequence is not separable. Through the operation of the cogitative power, experience becomes the source of scientific knowledge, by means of induction.
What The Physician Can Do
So, what happens in dementia? It may now be easier to understand that when the brain suffers:
...structural changes in neurons and their extensions, [they] contribute to a progressive disconnection of neural circuits serving memory and thinking (...) [which] helps lead to the impaired memory, judgment, abstraction and language that is too familiar in Alzheimer’s patients.1
Deterioration occurs without loss of faculties, but rather through the inability of the same to exert their operation in a defective organ. Let’s look at an example. In people who develop deafness because of lesions in the auditory organ of Corti (cells responsible for translating mechanical stimuli generated by the sound into nerve impulses degenerate), operation of the faculty of hearing is lost, but the faculty itself remains. This can be proven because implantation of a very crude electronic device which translates input (sound) in a range several orders of magnitude smaller than that of the organ of Corti (i.e., the biological transducer), can lead to full recovery of function, including the ability of speaking correctly. This recovery is accompanied by extensive remodelling of the brain connections and the creation of a new physical representation of auditory sensations in the brain. This kind of plasticity is the reason for most of the optimism in finding treatment for dementia. Indeed, it seems as if the soul had limitless ability to reorganize the operation of its faculties, provided a minimally adequate organ is provided.
At present, however, only marginally successful attempts have been made at improving the function of demented patients by medical treatments, and most of the hope is focused on developing medications which could arrest, or at least significantly slow down, the disease process.12 A few such medications are already in early stages of clinical application, such as drugs that enhance cognition, or so called nerve growth factors (and other drugs with unrelated mechanisms) which could prevent the progression of nerve cell death.12 In the meantime, the role of the physician is restricted in the first place to establishing the diagnosis, a very important step indeed, since on the one hand the same symptoms can be caused by reversible medical illnesses, and, on the other, early diagnosis may be the only case in which current medications are helpful. Secondly, the doctor has a role in supporting and orienting the family, and in providing prevention for severe complications such as accidental injury, malnutrition and infections, all of which occur far more easily in demented people.
Thou Shalt Honor Thy Father and Thy Mother
What to do, then, when one of our own is affected by this devastating illness? St. Thomas says:
After God, parents and our fatherland constitute principles of our being and government because we have been born from the former and raised in the latter. Therefore, after God, we owe the most to our parents and to our fatherland.13
This is the origin of the virtue of piety (pietas) by which we honor and serve our parents far beyond the exigence of justice, because there is no real proportion between what we can give back to them and what we actually owe them as our duty. Piety is somehow alike to the virtue of religion, and this likeness is not related to the end or object of the action, but to the human impossibility to reach a measure of retribution to either God or his parents. Hence, no sacrifice or task should be too big or too imposing when the object of our service is one of our parents.
It seems at times hard to reconcile the knowledge of the existence of a perfect, incorruptible intellect, with the view of this person we once knew, now “in second childhood and mere oblivion.” Nonetheless, we know that somehow the separable part of their soul is still there, shining in the darkness of a body now turned into a trap. That knowledge should suffice to cease not in our efforts to communicate our love to them. Modern man by his selfishness has lost all ability to see this truth, and equating appearance and essence, operation and faculty, can degrade himself to write, as the congressional Advisory Panel did, that:
...dementing disorders progress without mercy, robbing the sufferer of memory, of capacity, of humanity (emphasis mine).2
From here to euthanasia there is nothing but a short leap, for why not kill them if they are not human? God punishes the wise with blindness and confuses their understanding. The same Panel went on to say that:
No individual family is prepared emotionally, and very few economically, to care for an [Alzheimer’s disease]-afflicted relative; studies have shown that caring for a demented relative is among the most difficult forms of family responsibility, producing severe strain and potentially destructive effects on families that undertake caregiving.2
Although this statement may be well-meaning, I certainly hope that Catholic families will be an exception to this rule. The bigger the cross, the greater the graces that Our Lord grants the bearer, and the higher his or her place in heaven. The measure of our giving shall be all that we can give, and if we do it with righteous love, God will pay us hundredfold in our celestial home.
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