Vascular Accidents (Strokes) and Other Types of Cerebrovascular Disorders
What is a cerebrovascular disorder?
Cerebrovascular disorders occur when blood supply to the brain is interrupted. This can occur suddenly or gradually, be complete or relative, and be permiant or transient.
Cerebrovascular disorders are one of the most common causes of death in the developed world.
The different types of cerebrovascular disorders include:
Cerebrovascular Accident (a stroke)
Cerebrovascular Accident (Stroke)
A cerebrovascular accident is also known as a stroke. There are two different kinds - an ischemic stroke, and a hemorrhagic stroke.
An ischemic stroke occurs when a blood vessel carrying blood to the brain is blocked by a blood clot.
A hemorrhagic stroke occurs when a blood vessel ruptures, causing blood to leak into the brain.
Several diseases and disorders can cause ischemia. It is the most common type of stroke, accounting for about 87% of all cases.
There is also something known as a transient ischemic attack (TIA) which is temporary disruption of bloodflow caused by a clot.
An ischemic stroke can be further subdivided:
Throbotic: A clot (thrombus) develops in the arteries supplying blood to the brain.
Embolic: Also caused by a clot within the artery but, in this case, the clot (emboli) was formed somewhere other than the brain.
A hemorrhage is the breakage of a weak blood vessel. When this occurs in the brain, the supply of oxygen and glucose is disrupted. The blood that comes in contact with the neural tissue can also be toxic to it. As well, if there is enough pressure from the bleed, the displacement of neural centers may occur.
A brain hemorrhage may be caused by thrombosis, or embolism, hypertension, foreign objects, or if the artery has a weak spot called an aneurysm.
Intracerebral hemorrhage: If it occurs within the brain.
Subarachnoid hemorrhage: If it occurs between the pia and arachnoid sections of the meninges.
Thrombosis is when a bloodclot forms within a cerebral blod vessel, but can also be formed outside of the brain. It is commonly caused by atherosclerosis which is a build up of fatty deposits on walls of blood vessels leading to the blood vessels becoming restricted.
The constriction of blood flow can affect large areas of the brain. The symptoms are diffuse and gradual.
An embolism is similar to thrombosis. It is typically a clot but can be an air bubble or piece of fat. It travels through the bloodstream from one area of the body to another where it becomes lodged or wedged and causes blockage.