Cerebral Aneurysm

Also known as: Brain Aneurysm; Berry Aneurysm
What is it?
Cerebral aneurysms are abnormal saccular outpouchings of blood vessels occurring on blood vessels of the brain. Aneurysms usually at artery branch points and may take a variety of shapes and sizes. According to some studies, approximately 5% of the population may harbor brain aneurysms. Twenty percent of patients with one cerebral aneurysm will have additional aneurysms. Aneurysms usually cause medical problems by bleeding (rupture) or by putting pressure on near by brain structures.
Who gets it?
Most cerebral aneurysms are sporadic, in other words they are not related to any particular disease or inherited trait. Long-standing hypertension (high blood pressure) and smoking are risk factors for the development and rupture of brain aneurysms. Less commonly, aneurysms can occur in patients with a history of blood vessel wall abnormalities seen in such diseases as Marfan’s syndrome, polycystic kidney disease, fibromuscular dysplasia, connective tissue disorders and coarctation of the aorta. can also predispose patients to intracranial aneurysms. collagen vascular disorders. Aneurysms are usually not hereditary and most do not run in families. However, if a person has a family history of two or more first-degree relatives (e.g. sibling, parent or child) with cerebral aneurysms, the risk of having an aneurysm is increased. In such people, screening for an aneurysm with an MRI/MRA is generally recommended.
What causes it?
Cerebral aneurysms have been thought to develop from weaknesses in blood vessel walls especially at branching. Smoking, high blood pressure and certain connective tissue disorders appear to promote the development of aneurysms. Less commonly, aneurysms may be traumatic in nature secondary to blood vessel injury. Rarely, infectious causes can lead to what are referred to as mycotic aneurysms.
What are the symptoms?
Many patients with cerebral aneurysms have no symptoms. However, the most common reason brain aneurysms come to medical attention is through bleeding (rupture). The typical symptoms of brain aneurysm bleeding include, severe headache (usually described as the worst headache of the patient’s life), a stiff neck, light irritating the eyes and nausea/vomiting. In the absence of aneurysm bleeding, patients may develop focal neurological problems as a growing or changing aneurysm compresses normal brain structures.
How is it diagnosed?
Cerebral aneurysms can be noted on diagnostic imaging studies such as CT scans or MRI/MRA. However, the current gold standard for evaluation of cerebral aneurysms is cerebral angiography. During a cerebral angiogram a catheter is navigated into the arteries feeding the brain and x-ray pictures are obtained while contrast dye is injected through the catheter. Cerebral angiography is usually necessary prior to treatment of an aneurysm. In some situations a CT angiogram, which uses a CT scanner and intravenously injected contrast (no catheter), may be used to assist in delineating some features of the aneurysm.
What is the treatment?
The two major methods of aneurysm treatment are microsurgery and endovascular surgery. Microsurgical treatment for aneurysms involves an open surgical procedure to expose the aneurysm by slipping under and around the brain using delicate instruments and high-powered magnification. Once the aneurysm has been located, a titanium clip is placed across the neck (base) of the aneurysm. The clip stops blood from entering the aneurysm, thereby preventing it from bleeding. In endovascular surgery, a catheter is introduced into a patient's peripheral artery and navigated, using an angiogram as a "road map" to the area where the aneurysm is located. Once found, the aneurysm is then filled from the inside with tiny platinum “coils.” The coils react with the surrounding blood causing it to clot thereby obliterating the aneurysm. Both techniques are effective and each method has certain advantages and disadvantages that vary depending on the size, configuration and location of the aneurysm.
Currently, there are no medicines available to treat brain aneurysms. However, in some instances, depending on the patient’s age and general medical health, as well as the characteristics of the aneurysm itself, it is possible that no treatment will be recommended.