Pathophysiology of Hemorrhagic vs. Ischemic

Pathophysiology of Hemorrhagic vs. Ischemic Stroke

Strokes are the third leading cause of death in the United States, but there are two different kinds of strokes a person can have. The two major categories are hemorrhagic and ischemic. Hemorrhagic strokes come from the bursting of a blood vessel in the brain. Ischemic strokes come from a blood clot or other interruption to the blood supply. Nearly 87% of the strokes that are seen today are of the ischemic variety (Donnan, et al., 2008). In the ischemic stroke, there is a decrease in the supply of blood to a specific part of the brain. This results in dysfunction of the tissue in the brain in that area. There are four reasons why this kind of stroke and resulting dysfunction could take place:

Embolism

Venous Thrombosis

Thrombosis

Systemic Hypoperfusion (Warlow, 2008)

Despite all of the explanations that are available for the causes of strokes, there are still strokes that are termed "cryptogenic," meaning that they do not have an explanation that is obvious. Between 30 and 40% of ischemic strokes fall into the cryptogenic category and simply do not have a clear reason as to why they occurred (Donnan, et al., 2008; O'Regan, et al., 2008). Acute ischemic strokes have various classifications, as well. These classifications are based on the symptoms that are initially presented, along with the extent to which the symptoms are noticed (Warlow, 2008). By classifying a stroke correctly, the area of the brain that has been affected along with the extent of the stroke, the underlying cause of the stroke, and the patient's prognosis can all be addressed. Because there have been strides in medicine in recent years, more people who have ischemic strokes are able to get prompt treatment and regain much if not all of what they lost at the time that the stroke initially occurred.

Hemorrhagic strokes are far less common than ischemic strokes, but they can be much more devastating when they do occur (Warlow, 2008). These kinds of strokes take place when a blood vessel bursts or there is a leakage of blood in an area of blood vessel where there has been damage or an abnormal growth. There are two different kinds - those that cause blood between the brain and the skull, and those that actually cause blood inside the brain itself. Most hemorrhagic strokes have specific symptoms, including headaches. They can also cause vomiting and loss of consciousness because of increased intracranical pressure from the blood accumulation (Donnan, et al., 2008). Some of these kinds of strokes happen because of previous head injuries, but others occur in people who have no known head injuries and no known risk factors. These strokes are harder to treat than strokes that are ischemic in nature, but that does not mean that the prognosis for patients with these kinds of strokes is always a negative one.