Cerebrovascular effects
The brain is a major target of the deleterious effects exerted by hypertension and is responsible for a large portion of the related mortality and morbidity. Hypertension is the number one risk factor for stroke and is a leading cause of cognitive decline and dementia.
Many studies have focused on the possible mechanisms underlying hypertension-induced brain damage and recent advances in the comprehension of neurovascular regulation and of hypertension pathobiology, have led to a deeper insight of how hypertension may disrupt brain homeostasis. These new findings provide a unique opportunity for the dissection of molecular mechanisms at the basis of cerebrovascular effects of hypertension, and for the development of more selective therapies.
All the hypertension-induced structural alterations of cerebral blood vessels act in concert with the functional alterations of functional hyperemia, autoregulation, and endothelial function: the final outcome is a reduced compensatory capacity of the cerebral circulation and an increased susceptibility of the brain to vascular insufficiency.
Hypertension has a key role in two major brain pathologies, stroke and dementia. Stroke can result from the occlusion of a major cerebral artery (ischemic infarct) or rupture of intracerebral arterioles (hemorrhage). Hypertension also causes rupture of aneurysms of the circle of Willis, leading to bleeding into the subarachnoid space (subarachnoid hemorrhage). Vascular cognitive impairment (VCI) is caused by occlusion of small arterioles in the subcortical white matter, which interrupt neural connections subserving cognition and memory.
