Aneurysm is an abnormal expansion of blood vessels. Cerebral aneurysm, also referred as Brain aneurysm is an abnormal expansion of blood vessels in the brain. At the base of the brain is a tangle of arteries that make up the so-called Willis circle from which it continues to branch off to the arteries that supply the brain. Crossroads of these arteries are the most common places where cerebral aneurysms arise. They can occur in all, including the children, but is more common in adults aged 35-60 years, more frequently in women.