A cerebral (cranial) aneurysm is a weakened section in the wall of a blood vessel in the brain that bulges or balloons out.
Possible causes of cerebral aneurysm include: a defect in the blood vessels present at birth, brain tumour, head trauma or atherosclerosis (fatty deposits start to block the arteries).
A small aneurysm may produce no symptoms but as it grows it might cause vision problems, facial numbness or seizures.
A ruptured or burst aneurysm can cause bleeding in and around the brain which may affect mental skills and bodily functions and may, in serious cases, lead to brain damage, stroke, coma or death.
This is a treatment that can be used for both unruptured and ruptured aneurysms. The skull is opened surgically (craniotomy) and the aneurysm is isolated from the rest of the blood vessel using a small metal clip that seals off each end of the aneurysm.
This is a less invasive form of treatment that avoids the need for surgery. A catheter (a small, flexible tube) is inserted into an artery in the groin and gently pushed up to the brain. At the site of the aneurysm, the catheter releases soft wire coils that block the aneurysm from inside the blood vessel. Sometimes a tiny balloon is also released to help hold the coils in place.