Ischaemic Stroke
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Approximately 80% of strokes happen when a blood clot blocks one of the arteries carrying blood to the brain. This type of stroke is referred to as an Ischaemic Stroke.
Stroke causes some brain tissue to die. This area is called a cerebral infarction.
The following are three of the more common type of Ischaemic Stroke:
Cerebral Thrombosis
Cerebral Embolism
Lacunar Stroke
Cerebral Thrombosis
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is a blockage of an artery of the brain by a blood clot. Clots can form in arteries (blood vessels) that have already been narrowed by atherosclerosis (hardening of the arteries.)
Atherosclerosis causes fatty material to build up on the inside lining of the arteries, the arteries become narrower, and the blood flow is slowed down, making it more likely to form a clot.
Cerebral Embolism
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is a blockage or clot in the brain, but has originated somewhere else in the body. Sometimes, a clot can form in the blood vessels in the neck or in the heart. This clot may break off and travel in the bloodstream where it may lodge in a smaller blood vessel thus blocking the blood supply to that part of the brain.
Lacunar Stroke
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is where the small blood vessels deep in the brain become blocked as a result of damage over time.
Haemorrhagic Stroke
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About 20% of strokes are caused by bleeding from a burst blood vessel. Haemorrhagic Stroke
is a bleed into the brain as a result of a burst blood vessel. Bleeding can occur inside the brain itself - this is referred to as an intracerebral haemorrhage or a bleeding into the subarachnoid space (the lining protecting the brain) and is referred to as a subarachnoid haemorrhage. A blood vessel can burst due to changes made by atherosclerosis or as a result of a weakness in the vessel wall - an aneursym.
Transient Ischaemic Attack
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A transient ischaemic attack (TIA), is sometimes called a mini-stroke. It happens when the blood supply to the brain is interrupted for a short time.
A TIA is a major warning of a stroke and should never be ignored. The symptoms are the same as a stroke (i.e. weakness on one side of the body, loss of sight, slurred speech) but these symptoms are temporary – lasting from a few minutes or several hours, but always gone after 24 hours. In a TIA, the affected part of the brain is without oxygen for just a few minutes. A TIA is a sign that part of the brain is not getting enough blood and there is a risk of a more serious stroke in the future. |
