What Causes Cerebral Aneurysms?
Cerebral aneurysms can be congenital (present at birth), resulting from an inborn abnormality in an artery wall. They also are more common in people with certain genetic diseases, such as connective tissue disorders or polycystic kidney disease. They can be associated with other brain abnormalities such as an arteriovenous malformation (snarled tangles of arteries and veins in the brain that disrupt blood flow). This occurs roughly 10 percent of the time.
In children, especially, brain aneurysms may also result from a head injury, an infection in an arterial wall or may be associated with cancerous tumors of the head and neck. Aneurysms of these types tend to present most often as subarachnoid hemorrhages (bleeding between the brain and its surrounding membrane, the arachnoid).
Possible risk factors for rupture in adults include hypertension, alcohol abuse, drug abuse (particularly cocaine) and smoking.