Overview of Alzheimer's Disease and Its Effects on the Brain

Select network

                   

Alzheimer's disease is a serious malady of the central nervous system that affects a fairly large number of people in the nation, and especially the elderly. The purpose of the present sample essay provided by Ultius is to develop an overview of Alzheimer's disease and its effects on the brain.

Nature and prevalence of alzheimer's disease

The essay will have four main parts.

1. The first part of the essay will consist of an introduction to the nature and prevalence of the Alzheimer's disease.
2. The second part will describe what actually happens to the brain of a person who is afflicted by the illness.
3. The third part will discuss recent developments in research regarding Alzheimer's disease.
4. The fourth part will consider salient moral considerations regarding persons who have the illness. 

Alzheimer's disease is an illness of the central nervous system (i.e. the brain) that strongly affects the cognitive functioning of the patient. Some of the diagnostic criteria for the illness that have been delineated by the American Psychiatric Association (2000) include: memory impairment, language disturbance, cognitive disturbances that are consistent and not merely the result of delirium or substance abuse, and general gradual cognitive deterioration over time.

To an extent, then, Alzheimer's disease is diagnosed on the basis of exclusion of other diagnoses: if a given person is suffering from symptoms of cognitive deterioration and there is no other readily available explanation for why this is happening, then physicians generally consider it appropriate to make the diagnosis of Alzheimer's disease. This is especially the case of the person in question is elderly, since this is one of the most important predisposing factors for developing the illness.  

Conceptually, Alzheimer's disease can be understood as a form of dementia. There are many reasons why the brain can stop functioning to the point that cognitive functioning is impaired, and Alzheimer's disease is one of those reasons. According to Alzheimer's Foundation, the one in every nine Americans of 65 years of age or older suffer from Alzheimer's disease; one in three people people of age 85 or older suffer from the disease; and 82 percent of all people with the disease have an age of 75 years or older (16).

This indicates that Alzheimer's is strongly correlated with age: although it is not a natural consequence of aging, the aging process itself creates the relevant conditions of risk for the brain to develop this illness. Moreover, as the American population in general grows older, the prevalence of Alzheimer's disease within the nation can also be expected to increase.

Again, one in nine people who are 65 years of age older develop the illness; therefore, it logically follows that if the number of people who fall within this demographic group increases, then the number of people who suffer from Alzheimer's disease will also proportionally increase.

This is part of a broader trend that is taxing the resources of the American healthcare system as a whole. 

What does alxheimer's do to the brain?

Colbert has described the actual physiology of Alzheimer's disease in the following way:

"a protein called beta-amyloid shows up in irregular clumps or clusters in the brain. This protein comes from a precursor protein found in a fatty membrane that covers nerve cells. The clumps of beta-amyloid fragments stick together to form plaque. These sticky clusters interrupt signals between synapses" (2).

A synapse is essentially a space between neurons across which one neuron passes information to another neuron. If the synapse is blocked somehow, then this communication will not be able to occur in an effective way; and at the practical level, this interference manifests as the symptom of cognitive dysfunction. For example, a person with Alzheimer's disease may not be able to remember his friend's name, due to the fact that there is block in the pathways that would ordinarily facilitate this act of data retrieval.  

There has been some debate in the research literature about whether this build up of protein "plaque" within the brain is the actual cause of Alzheimer's disease, or whether the plaque itself is one of the effects (and not causes) of the disease process. Recent research on this subject seems to indicate that the plaque in fact serves the role of cause and not effect. As Belluck has reported:

"The largest analysis to date of amyloid plaques in people's brains confirms that the presence of the substance can help predict who will develop Alzheimer's and determine who has the disease" (paragraph 1).

That is, people who do not yet have Alzheimer's disease can be predicted to develop the disease on the basis of having this plaque in their brains. This means that the plaque logically and empirically precedes the onset of illness, which in turn means that the plaque cannot be a result of the illness. The only options are that: one, the plaque causes the illness; or two, that both the plaque and illness are caused by some other third factor of the lifecycle of human brain development.

In the vast majority of cases, Alzheimer's disease is caused by the aging process itself, which causes avoidable but nevertheless somewhat natural deterioration of the central nervous system. Alzheimer's in younger persons—that is, persons in their 30s through 50s—is

"called early-onset dominantly inherited Alzheimer's disease, always runs in families, and is caused by a mutation in one of three genes that a person has inherited from parents" (paragraph 12).

This kind of Alzheimer's, however, which can be traced to purely genetic causes, is extremely rare. Much more commonly, Alzheimer's disease occurs in older persons, for the simple reason that younger persons are almost physiologically incapable of suffering from the degeneration of the central nervous system that produces the hallmark symptoms of the illness. Advanced age is thus a very major risk factor for becoming afflicted with the disease. 

Recent developments in alzheimer's research

Groopman has written the following regarding the state of Alzheimer's research in the present day: the researchers

"mostly fall into two camps. The 'tauists' believe that the tau protein, tangled, within the neurons, causes dementia by disrupting the interior workings of the brain cells. The larger group, who call themselves 'baptists,' content that the beta-amyloid protein is the key to understanding the disease" (paragraph 17).

The baptists are different from the tauists in that whereas the tauists believe that the proteins cause internal disruptions within brain cells themselves, the baptists believe that the proteins primarily affect the synapses between brain cells. The accumulation of research over recent times tends to support the baptist position on this matter. This position has especially been supported by studies involving early onset Alzheimer's patients. While statistically a very rare form of Alzheimer's, research on this specific form of the disease has been able to cast light on the nature of the illness as a whole. 

Current research based on the baptist position is primarily based on trying to figure out how the protein plaque within the brain affects synapses, so that it could then become possible to counteract these proteins and thereby reverse the process of Alzheimer's disease. Research involving stem cells would seem to be especially promising in this regard. According to Euro Stem Cell,

"scientists bred mice with key symptoms and characteristics of Alzheimer's, such as memory impairment. They then injected neural stem cells into the brains of the mice and observed some improvement in memory" (paragraph 6).

The main empirical possibility here is that stem cells may be able to somehow rejuvenate the neurons within the brain in such a way that they no longer produce toxic protein plaque but are instead able to function in the natural way that neurons ordinarily function in younger persons. The feasibility of such a solution to Alzheimer's disease remains a subject of strong scientific debate. 

At the present time, though, there is no real cure for Alzheimer's disease. Drugs are sometimes utilized in order to control symptoms of dementia, and lifestyle recommendations are also often made, with an eye toward keeping the patient's mind as vigorous and youthful as possible. For example, it has been suggested by some parties that actively exercising the brain, through activities such as working on intellectual puzzles, could potentially help slow down and/or altogether halt the progress of Alzheimer's disease, as such activities would stimulate neural networks within the brain and as the breakdown of such networks that causes the symptoms of the illness.

In terms of empirical evidence, though, scientists are still somewhat unclear about the true causes of Alzheimer's disease, which means that it would be difficult to make objectively sound recommendations regarding specific activities or behaviors that could potentially address the illness. Present recommendations would seem to be based more on simple common sense than anything else.   

Moral considerations of alzheimer's research

One moral consideration that is quite relevant to the situation of Alzheimer's patients is the question of euthanasia. Insofar as Alzheimer's disease results in irreversible neurological degeneration, a patient who receives the diagnosis will know that in a matter of a few years, he will no longer be able to remember his life, recognize his friends and family, or personally take care of the basic functions of living.

Confronted with such a situation, a given person may well decide that he would like to end his own life before such extreme degeneration has the chance to occur. This would based on the simple value judgment that it would not be worthwhile to continue living, if one were to utterly lose one's whole sense of oneself. However, to acknowledge the patient's prerogative to end his own life on his terms would necessarily imply a kind of tacit endorsement of the practice of euthanasia. 

The legal scholar Dworkin has attempted to justify the right to request euthanasia in the case of dementia by making a conceptual distinction between critical interests and experiential interests (Henig). According to Dworkin, a critical interest speaks to the core of who a person is and what he believes to make his life worth living, whereas an experiential interest is more transitory and based on mood or situation rather than on fundamental identity.

The idea is that if a person changes in such a way that critical interests themselves begin to shift, then one could be meaningfully said to become a new person altogether, which would have implications for potential conflicts between the old and new "selves". For example, a person with late-stage Alzheimer's may feel himself to be happy, even as that same person several years ago would have thought very differently about the situation. In essence, Alzheimer's disease makes the moral question of euthanasia very problematic because the justification for euthanasia always hinges on the value of personal autonomy, and Alzheimer's specifically tends to undermine the very concept of autonomy itself.   

Conclusion 

In summary, this essay has consisted of an overview of Alzheimer's disease and its effects on the brain. It has been stated here that the pathophysiology of Alzheimer's disease primarily has to do with the emergence of protein plaque that prevents proper communications between the various neurons within the brain. Research into cures would thus need to focus on improving these communications and removing plaque from synapses; and that is why stem cell research is an especially promising are of research regarding Alzheimer's. The present essay has also engaged in a moral consideration and concluded that the disease in question can cause serious ethical dilemmas due to the fact that it destabilizes the very nature of what is ordinarily meant by basic concepts such as autonomy and selfhood.

Works Cited

Alzheimer's Association. "Alzheimer's Disease Facts and Figures." Alzheimer's & Dementia 10.2 (2014). Web. 31 Jul. 2015. <https://www.alz.org/downloads/Facts_Figures_2014.pdf>.

American Psychiatric Association. "DSM-IV Criteria for Diagnosis of Alzheimer's Disease." Diagnostic and Statistical Manual of Mental Disorders. Washington, D.C.: Author, 2000. Web. 31 Jul. 2015. <http://www.wai.wisc.edu/pdf/phystoolkit/diagnosis/DSM_IV_Criteria_Alzheimers_Disease.pdf>.

Belluck, Pam. "Studies Confirm Brain Plaque Can Help Predict Alzheimer's." New York Times. 19 May 2015. Web. 31 Jul. 2015. <http://www.nytimes.com/2015/05/20/health/studies-confirm-brain-plaque-can-help-predict-alzheimers.html?_r=0>. 

Colbert, Treacy. "What Does Alzheimer's Do to the Brain?" Healthline. 3 Dec. 2013. Web. 31 Jul. 2015. <http://www.healthline.com/health-slideshow/alzheimers-and-brain>. 

Euro Stem Cell. "Alzheimer's Disease: How Could Stem Cells Help." Author, 22 Jan. 2014. Web. 1 Aug. 2015. <http://www.eurostemcell.org/factsheet/alzheimer’s-disease-how-could-stem-cells-help>. 

Groopman, Jerome. "Before Night Falls." New Yorker. 24 Jun. 2013. Web. 31 Jul. 2015. <http://www.newyorker.com/magazine/2013/06/24/before-night-falls>. 

Henig, Robin Marantz. "The Last Day of Her Life." New York Times. 14 May 2015. Web. 31 Jul. 2015. <http://www.nytimes.com/2015/05/17/magazine/the-last-day-of-her-life.html>.