Cognitive function and low blood pressure in elderly people: no causal link, so it's all right to treat moderate hypertension.(Editorial)

Vascular damage of the brain is probably second only to Alzheimer's disease and related cerebral atrophies as a cause of dementia. Multiple cerebral infarcts, lacunes, subcortical arteriosclerotic encephalopathy (Binswanger's disease),[1] and the late sequelae of hypoxia and hypoperfusion are the main pathological substrates of vascular dementia. Hypertension is the single most important factor in the aetiology of cerebrovascular disease. Atherothrombotic brain infarction develops seven times more often in hypertensive people than in normotensive people. Of the 400 000 new strokes that occur annually in the United States, more than half are associated with or caused by hypertension, and borderline rises in blood pressure are seen with another 25%.[2] However, sustained low blood pressure and hypoxia secondary to hypoperfusion can also induce widespread cortical destruction with consequent dementia.[3] It is therefore reasonable to examine the relation between low blood pressure and dementia, especially since …