The relationship between blood pressure and dementia: a review.

Hypertension has been related to the development of dementia, including Alzheimer's disease, and cognitive dysfunction in middle-aged and elderly populations. One possible explanation is that hypertension is a risk factor for cerebral infarcts and ischaemic subcortical white-matter lesions. Hypertension may also give rise to a blood-brain barrier dysfunction, which has been suggested to be involved in the aetiology and pathogenesis of Alzheimer's disease. Other possible explanations for the association are shared risk factors, such as psychological stress, and the formation of free oxygen radicals. Low blood pressure has also been hypothesized to give rise to brain damage and dementia. However, the brain is involved in blood pressure regulation and dementia disorders may therefore influence the blood pressure. The findings of an association between hypertension and dementia may have implications for prevention and treatment.