A cerebral aneurysm is a disorder
that involves
localized widening of one or more blood
vessel(s) in the
brain.
Causes and
Risks
Aneurysms in the
brain occur when there is a weakened
area in the wall of
a blood vessel. They may occur as a
congenital defect or
may develop later in life.
A saccular aneurysm (berry
aneurysm) is usually
small in size. The aneurysm resembles
a sack of blood
attached to one side of the blood vessel
by a narrow
neck. These are more common in
adults. Multiple berry
aneurysms are not unusual. They occur
in any part of the
brain but are most often seen in the
large arteries at the
base of the brain. Berry aneurysm is
also associated with
polycystic kidney disease and
coarctation of the aorta.
Rarely, berry aneurysm can run in
families.
Other types of cerebral aneurysm
may involve
widening (dilatation) of the entire
circumference of the
blood vessel in an area, or may appear
as a ballooning
out of part of a blood vessel. These
types of aneurysms
can occur in any part of the brain.
Prevention
There is
no known way to
prevent formation of a cerebral
aneurysm. If discovered in
time, unruptured aneurysms can be
treated before
causing problems.
Symptoms
Symptoms
usually do not
appear until complications develop.
Bleeding is the most
common cause of symptoms, with
subarachnoid
hemorrhage the usual type of bleed.
Weakness,
numbness, or other loss of nerve
function (neurologic
deficits) may occur because of
pressure from the
aneurysm on adjacent brain tissue or
because of
reduced blood flow caused by a spasm
of other blood
vessels near a ruptured
aneurysm.
Symptoms of a
bleed may include:
- sudden occurrence of a headache
(severe or
described as "the worst in patient's
experience")
- headaches with nausea or
vomiting
- stiff neck (occasionally)
- muscle weakness, difficulty moving
any part of the
body
- numbness or decreased sensation
in any part of the
body
- vision changes
- eye lid drooping
- changes in mental status, the
person may be
lethargic, sleepy, or stuporous
- seizures
- slow, sluggish, lethargic movement
- speech impairment
- irritability or poor temper
control
Note: Cerebral aneurysms have no
symptoms until
complications such as bleeding occur.
Diagnosis
There may
be signs of
increased pressure within the brain
(intracranial
pressure) including swelling of the optic
nerve
(papilledema) that is shown on eye
examination.
Cerebral aneurysm is usually
diagnosed by tests to
determine the cause of bleeding within
the brain.
- A CT scan of the head indicates
bleeding and
occasionally locates the aneurysm.
- A CSF (cerebrospinal fluid)
examination may confirm
bleeding when CT scan is
non-diagnostic.
- An MRI of the head may be an
alternative to a CT
scan, but is not as sensitive to bleeding
within the brain
(subarachnoid bleeding).
- Cerebral angiography pinpoints the
location of the
aneurysm(s).
- EEG (electroencephalogram) may
be performed if
seizures occur.
Last Updated: December 03, 2007
