Treatment of Dementia with Vasoactive Drugs

Abstract

Both atherosclerosis and dementia are common in the elderly, and the incidence of both conditions increases throughout the sixth, seventh, and eighth decades of life (Keys, 1970; Mortimer et al, 1981). Brain cells, like those in other organs, require an adequate blood supply for survival and normal functioning. These facts, along with a lack of more precise knowledge about the causes of dementia in old age, led to the view, widely held for many years, that vascular disease was a primary cause of most age-related dementias. More specific formulations of this hypothesis often held that the loss of functioning brain cells in dementias of old age resulted from a lack of sufficient oxygen due to reduced blood flow (Jacobs et al., 1969). A variety of treatments designed to rectify these deficits by increasing either blood flow or oxygen availability were subsequently developed and tested. As our knowledge of the pathophysiology of dementia has increased, it has become clear that this view of the relationship of vascular disease to dementia is almost entirely wrong. Nevertheless, it is also clear that there are cerebrovascular changes associated with most age-related dementias. In addition, a variety of drugs that have been proposed as possible treatments for dementia have effects on the cerebral vascular system, although in many instances these may be only secondary effects.