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.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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