Estrogen and cerebral blood flow: a proposed mechanism to explain the observed benefit of estrogen replacement therapy on the prevention and treatment of Alzheimer's disease

Alzheimer's Disease effects women in far greater numbers than age-matched m en. Epidemiological data suggests that estrogen replacement therapy may dec rease the risk and reduce the progression of this neuro-degenerative condit ion. Thus far, there has not been a comprehensive theory to explain these o bservations. The data from this pilot study suggest that the vascular chang es associated with hot flush episodes may predispose certain brain regions to metabolic injury. This data also suggests that it is the ability of estr ogen to stabilize and augment cerebral blood flow that might lower Alzheime r's Disease risk in treated women. If confirmed in the larger study underwa y, this theory would provide greater evidence for a pathophysiologic role o f vascular changes as the initiating event in the inflammatory process that progresses to Alzheimer's dementia.