Aneurysm, brain

Aneurysm, brain: An aneurysm is a localized widening (dilatation) of an artery, vein, or the heart. At the area of an aneurysm, there is typically a bulge and the wall is weakened and may rupture. The word "aneurysm" comes from the Greek "aneurysma" meaning "a widening." A brain aneurysm is a small aneurysm that looks like a berry and classically occurs at the point at which a cerebral artery departs from the circular artery (the circle of Willis) at the base of the brain. Brain aneurysms rupture frequently and bleed. Also called a berry aneurysm.