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Cerebral Embolism Formation
Cardiac Sources
 Identification
of the sources of embolism has been problematic [Mohr JP and
Sacco RL, 1992]. Traditionally, the term "embolism"
refers to arterial thromboembolism stemming from a cardiac
source. The major source of cerebral emboli is the heart,
and for this to occur the abnormality, such as one resulting
in atrial fibrillation.
Cardiogenic emboli lodge in the
middle cerebral artery or its branches in 80% of cases, in
the posterior cerebral artery or its branches 10% of the time,
and in the vertebral artery or its branches in the remaining
10% of cases [Kistler JP, et al. In: Braunwald E, et al (eds).
Harrison's Principles of Internal Medicine. New York, McGraw-Hill,
1994:2250]. Cardiac emboli rarely reach the anterior
cerebral artery. If an embolus is large enough to occlude
the proximal stem of the middle cerebral artery (3 to 4 mm),
a major stroke results.
A cerebral embolus can also originate
in the internal carotid artery, where deposits of atheroma
cause stenosis of the artery. The site of this stenosis
is most often at the bifurcation of the common carotid artery
into its internal and external branches.
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Stroke Education
