What Are the Causes of Defective Blood Vessels in the Brain?
Defects in brain vessels, notably arteries, include hardening by atherosclerotic plaque, which narrows carotid arteries and can cause stroke; formation of berry aneurysms, which can rupture causing subarachnoid hemorrhage; deposition of amyloid in cerebral vessels, which can bleed; and congenital arteriovenous malformations, which can bleed.
