Case 2 Dementia (Monday afternoon)

"Dementia" is not a single disease, but a term that refers to a constellation of symptoms. It is an 'umbrella' term that can be caused by numerous diseases and conditions. In order to be labeled as suffering from "dementia" an individual must be experiencing some form of memory impairment and impairment in one, or more, cognitive domains.

Alzheimer's disease is, by far, the most common form of dementia.

Alzheimer's disease (AD) is characterized by unavoidable, progressive degeneration of the nerve cells of the brain. This deterioration initially begins in the hippocampus, structures that are located in the anterior poles of the temporal lobes. As the disease progresses, the association cortex of the parietal-occipital lobe junction and structures in the prefrontal cortex are negatively affected. Atrophy (shrinkage) is prominent in frontal, temporal, and parietal lobes. Microscopic findings are death of neurons in the cortex (outer covering of the brain), neurofibrillary tangles in the large neurons of the frontal and medial temporal structures, and senile plaques which are primarily concentrated in the medial temporal lobes. Neurochemical loss is associated with destruction of the nucleus basalis, the major source of cholinergic innervation to the cerebrum.

The most prominent cognitive deficits associated with AD are impairment in new memory and learning, difficulties with complex mental tracking, and deficits in language functioning and visuospatial abilities. Initially these cognitive deficits are insidious and may not be readily apparent, even to family members. Decline in work performance, or difficulty adjusting to unpredictable or unfamiliar events; however, may be noted. As the disease progresses, more cognitive abilities are disrupted and the disruptions become more severe.

Retrogenesis is a concept that refers to the process by which degenerative mechanisms reverse the order of acquisition in normal development. With AD, functional losses occur in the precise reversal in which they were acquired. In other words, things that an individual learned most recently are the very things that they will lose first. An Alzheimer's patient deteriorates backwards in time...losing first their ability to perform complex daily activities (such a managing their check book), then losing their ability to perform less complex daily activities (such as shopping, cooking, doing the laundry); as the disease progresses dressing becomes more difficult, then daily hygiene begins to suffer. Eventually the individual become totally dependent on others to provide the most basic of needs.