An aneurysm is a balloon-like bulge that occurs in a weak blood vessel, usually at the point where the vessel branches. This weak point in the vessel wall bulges under pressure as blood passes through it. Aneurysms may develop in any blood vessel in the body. However, the most common sites are the abdominal aorta and the brain.
An aneurysm that forms in the brain is called a cerebral aneurysm. Cerebral aneurysms are usually only symptomatic if they rupture and largely go undetected otherwise. If an aneurysm does burst, however, the consequences can be life threatening.
The rupture of an aneurysm is termed subarachnoid hemorrhage, an event that can cause severe brain damage. Some of the symptoms of subarachnoid hemorrhage include an intensely painful headache, stiff neck, nausea, vomiting and a painful sensitivity to light (photophobia). About 60% of people who suffer a subarachnoid hemorrhage die within two weeks. Of those who survive, about 50% will be severely brain damaged or disabled.
Cerebral aneurysms often go undetected due to the absence of symptoms but if an aneurysm is detected prior to rupture, preventative treatment may be recommended. However, the majority of aneurysms do not rupture and preventative treatments are generally only applicable in high risk cases.
When considering whether to recommend treatment, a doctor takes into account the patient’s risk factors for subarachnoid hemorrhage which include age, the size and location of the aneurysm, family medical history and general health. Treatment usually involves inserting tiny platinum coils into the aneurysm until blood can no longer enter it or sealing the aneurysm shut with a metal clip.