85 percent of Strokes are Ischemic Strokes Caused by a Clot
If you have an ischemic stroke, the artery that supplies oxygen-rich
blood to the brain becomes blocked. Blood clots often cause the
blockages that lead to ischemic strokes. When an artery to the brain is
blocked, the brain does not receive fresh blood from the heart and lungs
that supplies oxygen and nutrients to the brain, and takes away carbon
dioxide and cellular waste. If an artery is blocked, the brain cells
(neurons) cannot make enough energy and will eventually stop working. If
the artery remains blocked for more than a few minutes, the brain cells
may die. This is why immediate medical treatment is critical.
What causes Ischemic Stroke?
Ischemic stroke can be caused by several different kinds of diseases:
The most common problem is narrowing of the arteries in the neck
or head. This is most often caused by atherosclerosis, or
gradual cholesterol deposition. If the arteries become too
narrow, blood cells may collect and form blood clots. These
blood clots can block the artery where they are formed
(thrombosis), or can dislodge and become trapped in arteries
closer to the brain (embolism).
Another cause of stroke is blood clots in the heart, which can
occur as a result of irregular heartbeat (for example, atrial
fibrillation), heart attack, or abnormalities of the heart
While these are the most common causes of ischemic stroke, there
are many other possible causes. Examples include use of street
drugs, traumatic injury to the blood vessels of the neck, or
disorders of blood clotting.
Types of ischemic Stroke
Ischemic stroke can be divided into two main types:
Thrombotic – A thrombotic stroke occurs when diseased or damaged
cerebral arteries become blocked by the formation of a blood
clot within the brain. Clinically referred to as cerebral
thrombosis or cerebral infarction, this type of event is
responsible for almost 50 percent of all strokes. Cerebral
thrombosis can also be divided into an additional two categories
that correlate to the location of the blockage within the brain:
large-vessel thrombosis and small-vessel thrombosis.
Large-vessel thrombosis is the term used when the blockage is in
one of the brain’s larger blood-supplying arteries such as the
carotid or middle cerebral, while small-vessel thrombosis
involves one (or more) of the brain’s smaller, yet deeper,
penetrating arteries. This latter type of stroke is also called
a lacuner stroke.
Embolic – An embolic stroke is also caused by a clot within an
artery, but in this case the clot (or emboli) forms somewhere
other than in the brain itself. Often from the heart, these
emboli will travel in the bloodstream until they become lodged
and cannot travel any farther. This naturally restricts the flow
of blood to the brain and results in near-immediate physical and
Who is at Risk for Ischemic Stroke?
Stroke can affect people of all ages, including children.
Many people with ischemic strokes are older (60 or more years
old), and the risk of stroke increases with age.
Each year, about 55,000 more women than men have a stroke.
It is more common among African-Americans than members of other
Many people with stroke have other problems or conditions which
put them at higher risk for stroke, such as high blood pressure
(hypertension), heart disease, smoking, or diabetes.
Ischemic stroke, the most common type caused by a clot, can be treated
with medications such as antiplatelet medicines or blood thinners or
medical procedures to open up the blood flow to the brain.
if you believe you or someone else is experiencing a medical emergency.
For more information about Stroke Care at Main Line Health call 1.866.CALL.MLH.
For more information, call 1.866.CALL.MLH.