[Factors that modify the natural course of Alzheimer's disease]

Alzheimer s disease (AD) is an insidious, and progressive disorder of the nervous system that typically occurs after age 65, with incidence rising with chronological age. The disorder is characterized by a pronounced memory loss, due to neuropathological changes in the mesial temporal lobes; as the pathology spreads throughout the cerebral cortex. However, it is still unknown why some areas are more affected than others, with the subsequent clinical heterogeneity (or phenotypes), and variability in the clinical course. The most salient neurobehavioral syndromes that can affect the clinical course are extrapyramidal signs, as well as a wide variety of psychiatric syndromes (e.g., psychotic symptoms, depression, aggression). Similarly, medication use (e.g., antipsychotics, sedatives) have shown to have a detrimental effect in the course of the disease. Current palliative treatments for AD may alter the natural history of the disease by extending the time that affected patients may live at home.