e to the brain caused by the disease include inappropriate social behaviors, delusions and hallucinations.
However, the disease does not stop there. Its late stages are characterized by few or no verbal abilities, an inability to recognize family members or caregivers, a non-ambulatory state of being (meaning bedridden), and agitated behavior. Eventually the patient becomes completely dependent on others. The disease is terminal. Estimates of the disease's progression range from eight years to twenty years, though the average seems to be about ten.
Physical effects of the disease are limited to the brain. Alzheimer's causes the nerve cells to degenerate and the brain matter to shrink, in the process affecting the areas of the brain that control thought, memory, and language (JAMA, 1998, p.674). The hippocampus and neocortex undergo severe degeneration, especially the association between the cortex of the frontal and temporal lobes (Carlson, p. 429).
The brain develops neuritic plaques, which consist of a dense core of protein know as beta amyloid that is surrounded by degenerating axons and dendrites, along with activated microglia and reactive astrocytes (Carlson, p. 429). Neurofibrillary tangles can also be found. These are dying neurons that contain intercellular accumulations of twisted protein filaments that formerly served as the cells' internal skeleton (Carlson, p. 430). The neuritic plaques and neurofibrillary tangles prevent nutrients from getting delivered to the targeted brain cells and result in the cells= death. The end result is the symptoms described above (Sandroff, p. 68).
There are a number of possible causes for these developments currently being examined by researchers. One theory being explored is genetic. Familial Alzheimer's disease, sometimes referred to as FAD, accounts for about ten percent of all Alzheimer's cases (JAMA, 1998, p. 674). This form is the version typically diagnos...